diff --git a/NEWS b/NEWS
index 1885e0286..a7d5c6526 100644
--- a/NEWS
+++ b/NEWS
@@ -82,6 +82,12 @@ Changes to the Mercury standard library:
 * We have added the predicate unsorted_aggregate2/6 to the solutions module
   of the standard library.
 
+* We have added several predicates and functions to the error module
+  of the standard library. The predicates sorry/2 and sorry/3 report
+  the absence of a feature, while the predicates unexpected/2 and unexpected/3
+  report an internal error in the program; all have function versions too.
+  The predicate expect/3 calls unexpected if a condition isn't satisfied.
+
 Changes to the Mercury compiler:
 
 * We have added a new backend that generates C#.
diff --git a/compiler/accumulator.m b/compiler/accumulator.m
index 948c2bfc3..b2aa94d57 100644
--- a/compiler/accumulator.m
+++ b/compiler/accumulator.m
@@ -174,7 +174,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -192,6 +191,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/add_class.m b/compiler/add_class.m
index 796259a1f..e10f53690 100644
--- a/compiler/add_class.m
+++ b/compiler/add_class.m
@@ -60,7 +60,6 @@
 :- import_module hlds.make_hlds.make_hlds_warn.
 :- import_module hlds.make_hlds.state_var.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type.
 :- import_module parse_tree.prog_type_subst.
 :- import_module parse_tree.prog_util.
@@ -69,6 +68,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/add_clause.m b/compiler/add_clause.m
index 669959ee9..5bef72bec 100644
--- a/compiler/add_clause.m
+++ b/compiler/add_clause.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1993-2009 The University of Melbourne.
+% Copyright (C) 1993-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -72,7 +72,6 @@
 :- import_module hlds.make_hlds.make_hlds_warn.
 :- import_module hlds.make_hlds.superhomogeneous.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.mercury_to_mercury.
@@ -89,6 +88,7 @@
 :- import_module io.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module varset.
diff --git a/compiler/add_heap_ops.m b/compiler/add_heap_ops.m
index e1ff32e23..3c2baf202 100644
--- a/compiler/add_heap_ops.m
+++ b/compiler/add_heap_ops.m
@@ -48,7 +48,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.builtin_lib_types.
 :- import_module parse_tree.prog_data.
@@ -60,6 +59,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module term.
 :- import_module varset.
 
diff --git a/compiler/add_mode.m b/compiler/add_mode.m
index 997275279..6fefa4dc4 100644
--- a/compiler/add_mode.m
+++ b/compiler/add_mode.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1993-2006, 2008 The University of Melbourne.
+% Copyright (C) 1993-2006, 2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -38,10 +38,10 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.make_hlds.make_hlds_error.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_mode.
 
 :- import_module map.
+:- import_module require.
 
 %----------------------------------------------------------------------------%
 
diff --git a/compiler/add_pragma.m b/compiler/add_pragma.m
index a05af7152..4d105fe47 100644
--- a/compiler/add_pragma.m
+++ b/compiler/add_pragma.m
@@ -141,7 +141,6 @@
 :- import_module hlds.make_tags.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.
@@ -175,6 +174,7 @@
 :- import_module map.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/add_pred.m b/compiler/add_pred.m
index 802c04282..92bc25e2b 100644
--- a/compiler/add_pred.m
+++ b/compiler/add_pred.m
@@ -79,7 +79,6 @@
 :- import_module hlds.hlds_pred.
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.make_hlds.make_hlds_error.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.builtin_lib_types.
@@ -90,6 +89,7 @@
 
 :- import_module map.
 :- import_module set.
+:- import_module require.
 :- import_module term.
 :- import_module varset.
 
diff --git a/compiler/add_special_pred.m b/compiler/add_special_pred.m
index 79a6802f6..6d1bb22d4 100644
--- a/compiler/add_special_pred.m
+++ b/compiler/add_special_pred.m
@@ -70,7 +70,6 @@
 :- import_module hlds.make_hlds.add_pred.
 :- import_module hlds.pred_table.
 :- import_module hlds.special_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.prog_type.
@@ -80,6 +79,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module varset.
 
diff --git a/compiler/add_trail_ops.m b/compiler/add_trail_ops.m
index 7afc7f6b1..970485928 100644
--- a/compiler/add_trail_ops.m
+++ b/compiler/add_trail_ops.m
@@ -75,7 +75,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.builtin_lib_types.
@@ -88,6 +87,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module term.
 :- import_module varset.
 
diff --git a/compiler/add_type.m b/compiler/add_type.m
index 97c742918..e27b1f0f5 100644
--- a/compiler/add_type.m
+++ b/compiler/add_type.m
@@ -64,7 +64,6 @@
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_goal.
 :- import_module hlds.hlds_out.hlds_out_util.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.module_qual.
@@ -75,6 +74,7 @@
 :- import_module map.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module svmulti_map.
diff --git a/compiler/analysis.file.m b/compiler/analysis.file.m
index b916caaa9..1eb628c6a 100644
--- a/compiler/analysis.file.m
+++ b/compiler/analysis.file.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2003, 2005-2009 The University of Melbourne.
+% Copyright (C) 2003, 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU Library General
 % Public License - see the file COPYING.LIB in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -101,18 +101,6 @@
 
 :- implementation.
 
-:- import_module bool.
-:- import_module char.
-:- import_module dir.
-:- import_module exception.
-:- import_module parser.
-:- import_module term.
-:- import_module term_io.
-:- import_module type_desc.
-:- import_module univ.
-:- import_module varset.
-
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module libs.pickle.
@@ -121,6 +109,18 @@
 :- import_module parse_tree.prog_io_sym_name.
 :- import_module parse_tree.prog_out.
 
+:- import_module bool.
+:- import_module char.
+:- import_module dir.
+:- import_module exception.
+:- import_module parser.
+:- import_module require.
+:- import_module term.
+:- import_module term_io.
+:- import_module type_desc.
+:- import_module univ.
+:- import_module varset.
+
 %-----------------------------------------------------------------------------%
 
 % The format of an analysis result file is:
diff --git a/compiler/analysis.m b/compiler/analysis.m
index 8a6673193..7841cfbe7 100644
--- a/compiler/analysis.m
+++ b/compiler/analysis.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2003-2004, 2006-2009 The University of Melbourne.
+% Copyright (C) 2003-2004, 2006-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU Library General
 % Public License - see the file COPYING.LIB in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -319,11 +319,11 @@
 
 :- import_module analysis.file.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.                % XXX unwanted dependency
 :- import_module parse_tree.module_cmds.    % XXX unwanted dependency
 
 :- import_module map.
+:- import_module require.
 :- import_module string.
 :- import_module type_desc.
 :- import_module univ.
diff --git a/compiler/arg_info.m b/compiler/arg_info.m
index cfa255c3d..813abb7fd 100644
--- a/compiler/arg_info.m
+++ b/compiler/arg_info.m
@@ -114,10 +114,10 @@
 :- implementation.
 
 :- import_module check_hlds.mode_util.
-:- import_module libs.compiler_util.
 
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module int.
 :- import_module svset.
 
diff --git a/compiler/assertion.m b/compiler/assertion.m
index 0d4de0880..adb249597 100644
--- a/compiler/assertion.m
+++ b/compiler/assertion.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1999-2009 The University of Melbourne.
+% Copyright (C) 1999-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -134,7 +134,6 @@
 
 :- import_module hlds.goal_util.
 :- import_module hlds.hlds_clauses.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 
@@ -142,6 +141,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 
diff --git a/compiler/atsort.m b/compiler/atsort.m
index 02ee0be1f..b22ee8388 100644
--- a/compiler/atsort.m
+++ b/compiler/atsort.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-1995, 1997, 2004-2006 The University of Melbourne.
+% Copyright (C) 1994-1995, 1997, 2004-2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -47,7 +47,7 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
+:- import_module require.
 
 % :- pred main1(list(list(int))).
 % :- mode main1(out) is det.
diff --git a/compiler/base_typeclass_info.m b/compiler/base_typeclass_info.m
index 6130c095d..8914b7be5 100644
--- a/compiler/base_typeclass_info.m
+++ b/compiler/base_typeclass_info.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1996-2000, 2003-2007 The University of Melbourne.
+% Copyright (C) 1996-2000, 2003-2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -45,8 +45,6 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.hlds_rtti.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.
@@ -59,6 +57,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 
diff --git a/compiler/basic_block.m b/compiler/basic_block.m
index 1593711db..2e36e6c3d 100644
--- a/compiler/basic_block.m
+++ b/compiler/basic_block.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2001,2003-2007 The University of Melbourne.
+% Copyright (C) 1997-2001,2003-2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -99,10 +99,10 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.opt_util.
 
 :- import_module pair.
+:- import_module require.
 :- import_module svmap.
 :- import_module svset.
 
diff --git a/compiler/build_mode_constraints.m b/compiler/build_mode_constraints.m
index cd0f135cf..01b33aad1 100644
--- a/compiler/build_mode_constraints.m
+++ b/compiler/build_mode_constraints.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2004-2009 The University of Melbourne.
+% Copyright (C) 2004-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -201,8 +201,6 @@
 :- import_module hlds.hlds_args.
 :- import_module hlds.hlds_clauses.
 :- import_module hlds.hlds_desc.
-:- import_module libs.
-:- import_module libs.compiler_util.
 
 :- import_module bool.
 :- import_module cord.
@@ -211,6 +209,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svbimap.
 :- import_module svmulti_map.
diff --git a/compiler/bytecode.m b/compiler/bytecode.m
index 6f9ae0994..bb2c9f68e 100644
--- a/compiler/bytecode.m
+++ b/compiler/bytecode.m
@@ -152,10 +152,9 @@
 
 :- import_module backend_libs.bytecode_data.
 :- import_module backend_libs.c_util.
-:- import_module libs.
-:- import_module libs.compiler_util.
 
 :- import_module assoc_list.
+:- import_module require.
 :- import_module string.
 
 %---------------------------------------------------------------------------%
diff --git a/compiler/bytecode_data.m b/compiler/bytecode_data.m
index 9ebcc2752..db9b2421e 100644
--- a/compiler/bytecode_data.m
+++ b/compiler/bytecode_data.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1999-2000, 2003-2007, 2009 The University of Melbourne.
+% Copyright (C) 1999-2000, 2003-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -62,11 +62,9 @@
 
 :- implementation.
 
-:- import_module libs.
-:- import_module libs.compiler_util.
-
 :- import_module char.
 :- import_module int.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/bytecode_gen.m b/compiler/bytecode_gen.m
index c05958367..06a9b72fb 100644
--- a/compiler/bytecode_gen.m
+++ b/compiler/bytecode_gen.m
@@ -57,8 +57,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.passes_aux.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.
 :- import_module ll_backend.call_gen.  % XXX for arg passing convention
 :- import_module mdbcomp.
@@ -75,6 +73,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/call_gen.m b/compiler/call_gen.m
index 99747152c..38600ffa2 100644
--- a/compiler/call_gen.m
+++ b/compiler/call_gen.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1994-2009 The University of Melbourne.
+% Copyright (C) 1994-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -68,7 +68,6 @@
 :- import_module hlds.hlds_llds.
 :- import_module hlds.hlds_module.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module ll_backend.code_util.
 :- import_module ll_backend.continuation_info.
@@ -80,6 +79,7 @@
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/check_typeclass.m b/compiler/check_typeclass.m
index c59c9c674..1355e48b9 100644
--- a/compiler/check_typeclass.m
+++ b/compiler/check_typeclass.m
@@ -112,7 +112,6 @@
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -131,6 +130,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/clause_to_proc.m b/compiler/clause_to_proc.m
index 34b305cd3..42ae0738c 100644
--- a/compiler/clause_to_proc.m
+++ b/compiler/clause_to_proc.m
@@ -72,8 +72,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.make_hlds.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.
@@ -85,6 +83,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/closure_analysis.m b/compiler/closure_analysis.m
index b158b20d4..748f1710a 100644
--- a/compiler/closure_analysis.m
+++ b/compiler/closure_analysis.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2009 The University of Melbourne.
+% Copyright (C) 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -37,7 +37,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.prog_data.
@@ -51,6 +50,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/code_gen.m b/compiler/code_gen.m
index cfb4c111a..d3996a2b2 100644
--- a/compiler/code_gen.m
+++ b/compiler/code_gen.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1994-2009 The University of Melbourne.
+% Copyright (C) 1994-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -45,7 +45,6 @@
 :- import_module hlds.hlds_desc.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module ll_backend.call_gen.
 :- import_module ll_backend.commit_gen.
@@ -65,6 +64,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/code_info.m b/compiler/code_info.m
index 292875b1d..cd8b2942f 100644
--- a/compiler/code_info.m
+++ b/compiler/code_info.m
@@ -69,7 +69,6 @@
 :- import_module hlds.hlds_code_util.
 :- import_module hlds.hlds_desc.
 :- import_module hlds.hlds_rtti.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module libs.trace_params.
 :- import_module ll_backend.code_util.
@@ -82,6 +81,7 @@
 :- import_module cord.
 :- import_module int.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module stack.
 :- import_module string.
diff --git a/compiler/code_util.m b/compiler/code_util.m
index f65ec897c..4360a805b 100644
--- a/compiler/code_util.m
+++ b/compiler/code_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2009 The University of Melbourne.
+% Copyright (C) 1994-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -96,9 +96,9 @@
 :- import_module backend_libs.proc_label.
 :- import_module backend_libs.rtti.
 :- import_module hlds.code_model.
-:- import_module libs.compiler_util.
 
 :- import_module int.
+:- import_module require.
 :- import_module term.
 
 %---------------------------------------------------------------------------%
diff --git a/compiler/commit_gen.m b/compiler/commit_gen.m
index b8237da69..64ac66162 100644
--- a/compiler/commit_gen.m
+++ b/compiler/commit_gen.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1997-1998, 2003-2007, 2009 The University of Melbourne.
+% Copyright (C) 1997-1998, 2003-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -35,12 +35,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.code_gen.
 
 :- import_module cord.
 :- import_module list.
 :- import_module maybe.
+:- import_module require.
 :- import_module pair.
 :- import_module string.
 
diff --git a/compiler/common.m b/compiler/common.m
index 1e03cdc31..c23a9e511 100644
--- a/compiler/common.m
+++ b/compiler/common.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1995-2009 The University of Melbourne.
+% Copyright (C) 1995-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -98,7 +98,6 @@
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.instmap.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module parse_tree.error_util.
 :- import_module parse_tree.prog_type.
@@ -110,6 +109,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module sveqvclass.
 :- import_module svmap.
diff --git a/compiler/compile_target_code.m b/compiler/compile_target_code.m
index e5ec04aae..ce0a0b072 100644
--- a/compiler/compile_target_code.m
+++ b/compiler/compile_target_code.m
@@ -235,7 +235,6 @@
 :- import_module hlds.
 
 :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.handle_options.
 :- import_module libs.options.
@@ -250,6 +249,7 @@
 
 :- import_module dir.
 :- import_module getopt_io.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/compiler_util.m b/compiler/compiler_util.m
index 00a31a9c6..01f958286 100644
--- a/compiler/compiler_util.m
+++ b/compiler/compiler_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2006, 2009 The University of Melbourne.
+% Copyright (C) 1997-2006, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -22,28 +22,6 @@
 
 %-----------------------------------------------------------------------------%
 
-    % Call error/1 with a "Sorry, not implemented" message.
-    %
-    % Use this for features that should be implemented (or at least could be
-    % implemented).
-    %
-:- func sorry(string, string) = _ is erroneous.
-:- pred sorry(string::in, string::in) is erroneous.
-
-    % unexpected(ModuleName, Message):
-    %
-    % Call error/1 with an "Unexpected" message.
-    % Use this to handle cases which are not expected to arise (i.e. bugs).
-    %
-:- func unexpected(string, string) = _ is erroneous.
-:- pred unexpected(string::in, string::in) is erroneous.
-    
-    % expect(Goal, ModuleName, Message):
-    %
-    % Call Goal, and call unexpected(ModuleName, Message) if Goal fails.
-    %
-:- pred expect((pred)::((pred) is semidet), string::in, string::in) is det.
-
     % Record the fact that a warning has been issued; set the exit status
     % to error if the `--halt-at-warn' option is set.
     %
@@ -74,26 +52,6 @@
 
 %-----------------------------------------------------------------------------%
 
-    % Call error/1 with a "Sorry, not implemented" message.
-    %
-sorry(Module, What) = _ :- sorry(Module, What).
-sorry(Module, What) :-
-    string.format("%s: Sorry, not implemented: %s",
-        [s(Module), s(What)], ErrorMessage),
-    error(ErrorMessage).
-
-unexpected(Module, What) = _ :- unexpected(Module, What).
-unexpected(Module, What) :-
-    string.format("%s: Unexpected: %s", [s(Module), s(What)], ErrorMessage),
-    error(ErrorMessage).
-
-expect(Goal, Module, Message) :-
-    ( Goal ->
-        true
-    ;
-        unexpected(Module, Message)
-    ).
-
 record_warning(Globals, !IO) :-
     globals.lookup_bool_option(Globals, halt_at_warn, HaltAtWarn),
     (
diff --git a/compiler/complexity.m b/compiler/complexity.m
index 644957b77..a41c6c430 100644
--- a/compiler/complexity.m
+++ b/compiler/complexity.m
@@ -66,7 +66,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -83,6 +82,7 @@
 :- import_module int.
 :- import_module list.
 :- import_module map.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/constraint.m b/compiler/constraint.m
index a7b3e04a2..66d0bc74f 100644
--- a/compiler/constraint.m
+++ b/compiler/constraint.m
@@ -53,7 +53,6 @@
 :- import_module check_hlds.inst_match.
 :- import_module hlds.goal_form.
 :- import_module hlds.goal_util.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 
@@ -61,6 +60,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/continuation_info.m b/compiler/continuation_info.m
index 0ef81adce..9ef47a753 100644
--- a/compiler/continuation_info.m
+++ b/compiler/continuation_info.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2000,2002-2009 The University of Melbourne.
+% Copyright (C) 1997-2000,2002-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -408,12 +408,12 @@
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_llds.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module ll_backend.code_util.
 :- import_module parse_tree.prog_type.
 
 :- import_module int.
+:- import_module require.
 :- import_module solutions.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/coverage_profiling.m b/compiler/coverage_profiling.m
index f87af0d9e..839d7cf09 100644
--- a/compiler/coverage_profiling.m
+++ b/compiler/coverage_profiling.m
@@ -45,7 +45,6 @@
 
 :- import_module hlds.goal_util.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.deep_profiling.
@@ -56,6 +55,7 @@
 :- import_module counter.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/cse_detection.m b/compiler/cse_detection.m
index 6b1fb954e..25b8e33db 100644
--- a/compiler/cse_detection.m
+++ b/compiler/cse_detection.m
@@ -47,7 +47,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.quantification.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -64,6 +63,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/ctgc.fixpoint_table.m b/compiler/ctgc.fixpoint_table.m
index f1b5e4026..1c92492c5 100644
--- a/compiler/ctgc.fixpoint_table.m
+++ b/compiler/ctgc.fixpoint_table.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006 The University of Melbourne.
+% Copyright (C) 2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -89,11 +89,10 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module int.
 :- import_module list.
 :- import_module map.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/ctgc.livedata.m b/compiler/ctgc.livedata.m
index a83c53e8c..7668e071e 100644
--- a/compiler/ctgc.livedata.m
+++ b/compiler/ctgc.livedata.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006 The University of Melbourne.
+% Copyright (C) 2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -87,11 +87,11 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module transform_hlds.ctgc.datastruct.
 :- import_module transform_hlds.ctgc.structure_sharing.domain.
 
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/ctgc.selector.m b/compiler/ctgc.selector.m
index f40a3df7f..8b3bc5e20 100644
--- a/compiler/ctgc.selector.m
+++ b/compiler/ctgc.selector.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2006, 2008-2009 The University of Melbourne.
+% Copyright (C) 2005-2006, 2008-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -87,7 +87,6 @@
 :- implementation.
 
 :- import_module check_hlds.type_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type.
 
 :- import_module assoc_list.
@@ -96,6 +95,7 @@
 :- import_module map.
 :- import_module pair.
 :- import_module queue.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/ctgc.util.m b/compiler/ctgc.util.m
index c254b583f..1af413e23 100644
--- a/compiler/ctgc.util.m
+++ b/compiler/ctgc.util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006-2008 The University of Melbourne.
+% Copyright (C) 2006-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -76,13 +76,13 @@
 :- implementation.
 
 :- import_module check_hlds.type_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type.
 :- import_module parse_tree.prog_type_subst.
 
 :- import_module bool.
 :- import_module list.
 :- import_module map.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/dead_proc_elim.m b/compiler/dead_proc_elim.m
index 81e9b17d8..125ac7043 100644
--- a/compiler/dead_proc_elim.m
+++ b/compiler/dead_proc_elim.m
@@ -84,7 +84,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.error_util.
@@ -96,6 +95,7 @@
 :- import_module maybe.
 :- import_module pair.
 :- import_module queue.
+:- import_module require.
 :- import_module set_tree234.
 :- import_module set.
 :- import_module string.
diff --git a/compiler/deforest.m b/compiler/deforest.m
index 6ad2b413b..ec515eedb 100644
--- a/compiler/deforest.m
+++ b/compiler/deforest.m
@@ -60,7 +60,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.passes_aux.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -84,6 +83,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/delay_construct.m b/compiler/delay_construct.m
index e594449fb..2c2aab0d2 100644
--- a/compiler/delay_construct.m
+++ b/compiler/delay_construct.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001-2009 The University of Melbourne.
+% Copyright (C) 2001-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -45,7 +45,6 @@
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.instmap.
 :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module parse_tree.prog_data.
 
@@ -53,6 +52,7 @@
 :- import_module io.
 :- import_module list.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/delay_info.m b/compiler/delay_info.m
index 4f1573d8e..154a77d2f 100644
--- a/compiler/delay_info.m
+++ b/compiler/delay_info.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-1998, 2003-2007, 2009 The University of Melbourne.
+% Copyright (C) 1994-1998, 2003-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -90,13 +90,12 @@
 :- implementation.
 
 :- import_module check_hlds.mode_errors.   % for the mode_error_info
-                                            % and delay_info types.
-:- import_module libs.
-:- import_module libs.compiler_util.
+                                           % and delay_info types.
 
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module stack.
 :- import_module svmap.
diff --git a/compiler/delay_partial_inst.m b/compiler/delay_partial_inst.m
index 3a68b5f00..3f2349208 100644
--- a/compiler/delay_partial_inst.m
+++ b/compiler/delay_partial_inst.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007-2009 The University of Melbourne.
+% Copyright (C) 2007-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -132,8 +132,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.passes_aux.
 :- import_module hlds.quantification.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.
 :- import_module parse_tree.prog_data.
 
@@ -143,6 +141,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/dense_switch.m b/compiler/dense_switch.m
index d83b559fe..41cb056d9 100644
--- a/compiler/dense_switch.m
+++ b/compiler/dense_switch.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2007, 2009 The University of Melbourne.
+% Copyright (C) 1994-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -58,7 +58,6 @@
 :- import_module hlds.hlds_llds.
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_goal.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.code_gen.
 :- import_module ll_backend.trace_gen.
 :- import_module parse_tree.prog_type.
@@ -69,6 +68,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/dep_par_conj.m b/compiler/dep_par_conj.m
index 20669aa0a..6c43c3914 100644
--- a/compiler/dep_par_conj.m
+++ b/compiler/dep_par_conj.m
@@ -151,7 +151,6 @@
 :- import_module hlds.hlds_pred.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -168,6 +167,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module std_util.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/det_analysis.m b/compiler/det_analysis.m
index a0cfa869f..7edde4a19 100644
--- a/compiler/det_analysis.m
+++ b/compiler/det_analysis.m
@@ -122,7 +122,6 @@
 :- import_module libs.
 :- import_module libs.file_util.
 :- import_module libs.globals.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_data.
@@ -134,6 +133,7 @@
 :- import_module io.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/det_report.m b/compiler/det_report.m
index fbec440e2..29b8b4403 100644
--- a/compiler/det_report.m
+++ b/compiler/det_report.m
@@ -145,7 +145,6 @@
 :- import_module hlds.hlds_out.hlds_out_goal.
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
@@ -163,6 +162,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set_tree234.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/det_util.m b/compiler/det_util.m
index 8158f7beb..2bc918054 100644
--- a/compiler/det_util.m
+++ b/compiler/det_util.m
@@ -118,13 +118,13 @@
 :- implementation.
 
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.prog_type.
 :- import_module parse_tree.prog_util.
 
 :- import_module map.
+:- import_module require.
 :- import_module set_tree234.
 :- import_module term.
 
diff --git a/compiler/disj_gen.m b/compiler/disj_gen.m
index 0da14260d..5d2bb1972 100644
--- a/compiler/disj_gen.m
+++ b/compiler/disj_gen.m
@@ -40,7 +40,6 @@
 :- import_module backend_libs.builtin_ops.
 :- import_module hlds.goal_form.
 :- import_module hlds.hlds_llds.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.code_gen.
@@ -57,6 +56,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 
diff --git a/compiler/dupelim.m b/compiler/dupelim.m
index b1e6108e7..4c6e4c573 100644
--- a/compiler/dupelim.m
+++ b/compiler/dupelim.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1995-2007, 2009 The University of Melbourne.
+% Copyright (C) 1995-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -61,7 +61,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.basic_block.
 :- import_module ll_backend.opt_util.
 
@@ -69,6 +68,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module svset.
diff --git a/compiler/dupproc.m b/compiler/dupproc.m
index f96f491bd..15bec0e30 100644
--- a/compiler/dupproc.m
+++ b/compiler/dupproc.m
@@ -37,12 +37,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.opt_util.
 
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/elds.m b/compiler/elds.m
index 230b71b6e..3907c9f0c 100644
--- a/compiler/elds.m
+++ b/compiler/elds.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007 The University of Melbourne.
+% Copyright (C) 2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -99,7 +99,7 @@
     %
 :- type elds_rtti_defn
     --->    elds_rtti_defn(
-                rtti_defn_id        :: elds_rtti_id, 
+                rtti_defn_id        :: elds_rtti_id,
                 rtti_defn_exported  :: bool,
                 rtti_defn_varset    :: prog_varset,
                 rtti_defn_clause    :: elds_clause
@@ -256,7 +256,7 @@
     --->    elds_case(elds_term, elds_expr).
 
 :- type elds_catch
-    --->    elds_catch(elds_term, elds_term, elds_expr). 
+    --->    elds_catch(elds_term, elds_term, elds_expr).
 
 :- type elds_unop
     --->    plus
@@ -385,7 +385,7 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/elds_to_erlang.m b/compiler/elds_to_erlang.m
index ab7f054c8..55e2cc323 100644
--- a/compiler/elds_to_erlang.m
+++ b/compiler/elds_to_erlang.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007-2009 The University of Melbourne.
+% Copyright (C) 2007-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -47,7 +47,6 @@
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.pred_table.
 :- import_module hlds.special_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module mdbcomp.prim_data.
@@ -65,6 +64,7 @@
 :- import_module list.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/equiv_type.m b/compiler/equiv_type.m
index 847863df8..f89e355fa 100644
--- a/compiler/equiv_type.m
+++ b/compiler/equiv_type.m
@@ -109,7 +109,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_mode.
 :- import_module parse_tree.prog_util.
@@ -119,6 +118,7 @@
 :- import_module assoc_list.
 :- import_module bool.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module term.
diff --git a/compiler/equiv_type_hlds.m b/compiler/equiv_type_hlds.m
index 21331dfc8..49c0baf72 100644
--- a/compiler/equiv_type_hlds.m
+++ b/compiler/equiv_type_hlds.m
@@ -41,7 +41,6 @@
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.instmap.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.equiv_type.
 :- import_module parse_tree.prog_data.
@@ -54,6 +53,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module svset.
diff --git a/compiler/erl_call_gen.m b/compiler/erl_call_gen.m
index 9fff47698..b2d78dad9 100644
--- a/compiler/erl_call_gen.m
+++ b/compiler/erl_call_gen.m
@@ -106,11 +106,11 @@
 :- import_module backend_libs.builtin_ops.
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_module.
-:- import_module libs.compiler_util.
 
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 %
diff --git a/compiler/erl_code_gen.m b/compiler/erl_code_gen.m
index 12e9c921e..0386ef98b 100644
--- a/compiler/erl_code_gen.m
+++ b/compiler/erl_code_gen.m
@@ -59,7 +59,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -72,6 +71,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module varset.
diff --git a/compiler/erl_code_util.m b/compiler/erl_code_util.m
index fffbdd6c3..aac069170 100644
--- a/compiler/erl_code_util.m
+++ b/compiler/erl_code_util.m
@@ -1,16 +1,16 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007-2008 The University of Melbourne.
+% Copyright (C) 2007-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
-% 
+%
 % File: erl_code_util.m.
 % Main author: wangp.
-% 
+%
 % This module is part of the Erlang code generator.
-% 
+%
 %-----------------------------------------------------------------------------%
 
 :- module erl_backend.erl_code_util.
@@ -211,11 +211,11 @@
 :- import_module check_hlds.mode_util.
 :- import_module check_hlds.type_util.
 :- import_module hlds.goal_util.
-:- import_module libs.compiler_util.
 
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svset.
 :- import_module term.
diff --git a/compiler/erl_rtti.m b/compiler/erl_rtti.m
index db4edfd76..a13b662f9 100644
--- a/compiler/erl_rtti.m
+++ b/compiler/erl_rtti.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007, 2009 The University of Melbourne.
+% Copyright (C) 2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -49,7 +49,6 @@
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.hlds_rtti.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_util.
@@ -59,6 +58,7 @@
 :- import_module exception.
 :- import_module int.
 :- import_module maybe.
+:- import_module require.
 :- import_module string.
 :- import_module svvarset.
 :- import_module univ.
diff --git a/compiler/erl_unify_gen.m b/compiler/erl_unify_gen.m
index 620cced0c..c808dd0bb 100644
--- a/compiler/erl_unify_gen.m
+++ b/compiler/erl_unify_gen.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007-2009 The University of Melbourne.
+% Copyright (C) 2007-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -83,7 +83,6 @@
 :- import_module erl_backend.erl_call_gen.
 :- import_module hlds.hlds_module.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_util.
@@ -92,6 +91,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/exception_analysis.m b/compiler/exception_analysis.m
index c088fada1..325fcccb0 100644
--- a/compiler/exception_analysis.m
+++ b/compiler/exception_analysis.m
@@ -130,7 +130,6 @@
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -146,6 +145,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 
diff --git a/compiler/export.m b/compiler/export.m
index 612a2eda7..fc1474d3b 100644
--- a/compiler/export.m
+++ b/compiler/export.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1996-2009 The University of Melbourne.
+% Copyright (C) 1996-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -81,20 +81,18 @@
 
 :- implementation.
 
-:- import_module check_hlds.        % needed for type_util, mode_util
-:- import_module libs.
-
 :- import_module backend_libs.c_util.
 :- import_module backend_libs.foreign.
 :- import_module backend_libs.name_mangle.
 :- import_module backend_libs.proc_label.
+:- import_module check_hlds.
 :- import_module check_hlds.type_util.
 :- import_module hlds.arg_info.
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
+:- import_module libs.
 :- import_module libs.globals.
 :- import_module parse_tree.file_names.
 :- import_module parse_tree.module_cmds.
@@ -109,6 +107,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 
diff --git a/compiler/fact_table.m b/compiler/fact_table.m
index cb12b5333..5b2cb5274 100644
--- a/compiler/fact_table.m
+++ b/compiler/fact_table.m
@@ -102,7 +102,6 @@
 :- import_module hlds.arg_info.
 :- import_module hlds.code_model.
 :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -127,6 +126,7 @@
 :- import_module maybe.
 :- import_module pair.
 :- import_module parser.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 :- import_module term_io.
diff --git a/compiler/field_access.m b/compiler/field_access.m
index b781449cf..4faedbd54 100644
--- a/compiler/field_access.m
+++ b/compiler/field_access.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1993-2006, 2008-2009 The University of Melbourne.
+% Copyright (C) 1993-2006, 2008-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -105,12 +105,12 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.make_hlds.superhomogeneous.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_io_sym_name.
 
 :- import_module bool.
 :- import_module int.
+:- import_module require.
 :- import_module term.
 :- import_module varset.
 
diff --git a/compiler/file_names.m b/compiler/file_names.m
index c40c9d877..2018f4e4f 100644
--- a/compiler/file_names.m
+++ b/compiler/file_names.m
@@ -133,7 +133,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.handle_options.
 :- import_module libs.options.
@@ -146,6 +145,7 @@
 :- import_module dir.
 :- import_module library.
 :- import_module list.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/follow_code.m b/compiler/follow_code.m
index fd5b91ac6..bbe4adf86 100644
--- a/compiler/follow_code.m
+++ b/compiler/follow_code.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2009 The University of Melbourne.
+% Copyright (C) 1994-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -51,7 +51,6 @@
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.instmap.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.prog_data.
@@ -59,6 +58,7 @@
 :- import_module bool.
 :- import_module list.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/follow_vars.m b/compiler/follow_vars.m
index d70898a52..45ad09e0b 100644
--- a/compiler/follow_vars.m
+++ b/compiler/follow_vars.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2008 The University of Melbourne.
+% Copyright (C) 1994-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -53,7 +53,6 @@
 
 :- import_module hlds.arg_info.
 :- import_module hlds.code_model.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.call_gen.
 :- import_module parse_tree.prog_data.
 
@@ -64,6 +63,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/foreign.m b/compiler/foreign.m
index 99f8cc77d..57268624a 100644
--- a/compiler/foreign.m
+++ b/compiler/foreign.m
@@ -157,7 +157,6 @@
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_pred.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module parse_tree.error_util.
 :- import_module parse_tree.prog_out.
@@ -169,6 +168,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/frameopt.m b/compiler/frameopt.m
index 1348d2b6a..c997a3823 100644
--- a/compiler/frameopt.m
+++ b/compiler/frameopt.m
@@ -154,7 +154,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module ll_backend.opt_debug.
 :- import_module ll_backend.opt_util.
@@ -166,6 +165,7 @@
 :- import_module maybe.
 :- import_module pair.
 :- import_module queue.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/globals.m b/compiler/globals.m
index 7b1aabc7e..d7c377884 100644
--- a/compiler/globals.m
+++ b/compiler/globals.m
@@ -295,9 +295,8 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module int.
+:- import_module require.
 :- import_module string.
 :- import_module univ.
 
diff --git a/compiler/goal_form.m b/compiler/goal_form.m
index fc38185ee..72e23b3bb 100644
--- a/compiler/goal_form.m
+++ b/compiler/goal_form.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002-2009 The University of Melbourne.
+% Copyright (C) 2002-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -186,7 +186,6 @@
 
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_goal.
-:- import_module libs.compiler_util.
 :- import_module transform_hlds.exception_analysis.
 :- import_module transform_hlds.term_constr_main.
 
@@ -195,6 +194,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/goal_path.m b/compiler/goal_path.m
index 1027b9320..ec1928ddc 100644
--- a/compiler/goal_path.m
+++ b/compiler/goal_path.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2009 University of Melbourne.
+% Copyright (C) 1997-2010 University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -61,8 +61,6 @@
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_clauses.
 :- import_module hlds.hlds_goal.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.program_representation.
 :- import_module parse_tree.prog_data.
@@ -73,6 +71,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/goal_util.m b/compiler/goal_util.m
index ec7da0dbb..41506f2ec 100644
--- a/compiler/goal_util.m
+++ b/compiler/goal_util.m
@@ -451,7 +451,6 @@
 :- import_module check_hlds.type_util.
 :- import_module hlds.goal_form.
 :- import_module hlds.hlds_llds.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_mode.
 :- import_module parse_tree.prog_type.
@@ -460,6 +459,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module solutions.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/granularity.m b/compiler/granularity.m
index 7ade7bc9f..256391c97 100644
--- a/compiler/granularity.m
+++ b/compiler/granularity.m
@@ -31,7 +31,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module transform_hlds.dependency_graph.
@@ -44,6 +43,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/graph_colour.m b/compiler/graph_colour.m
index 02a3da1e8..2c4c186c6 100644
--- a/compiler/graph_colour.m
+++ b/compiler/graph_colour.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1995-1996, 2004-2006 The University of Melbourne.
+% Copyright (C) 1995-1996, 2004-2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -33,9 +33,8 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module list.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/headvar_names.m b/compiler/headvar_names.m
index 42e2f5b55..f195364c9 100644
--- a/compiler/headvar_names.m
+++ b/compiler/headvar_names.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007, 2009 The University of Melbourne.
+% Copyright (C) 2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -36,7 +36,6 @@
 :- import_module hlds.hlds_clauses.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.goal_util.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module parse_tree.prog_data.
 
@@ -44,6 +43,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module varset.
 :- import_module svmap.
diff --git a/compiler/hhf.m b/compiler/hhf.m
index 174e1e671..efdcb93e0 100644
--- a/compiler/hhf.m
+++ b/compiler/hhf.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001-2002, 2004-2009 The University of Melbourne.
+% Copyright (C) 2001-2002, 2004-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -46,7 +46,6 @@
 :- import_module hlds.hlds_args.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_type.
 :- import_module parse_tree.prog_util.
@@ -56,6 +55,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module term.
diff --git a/compiler/higher_order.m b/compiler/higher_order.m
index 94ed424f7..f7cb0ee7b 100644
--- a/compiler/higher_order.m
+++ b/compiler/higher_order.m
@@ -59,7 +59,6 @@
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
 :- import_module hlds.special_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -79,6 +78,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
@@ -88,10 +88,10 @@
 
 %-----------------------------------------------------------------------------%
 
-    % Iterate collecting requests and processing them until there are no more
-    % requests remaining.
-    %
 specialize_higher_order(!ModuleInfo, !IO) :-
+    % Iterate collecting requests and process them until there are no more
+    % requests remaining.
+
     module_info_get_globals(!.ModuleInfo, Globals),
     globals.lookup_bool_option(Globals, optimize_higher_order, HigherOrder),
     globals.lookup_bool_option(Globals, type_specialization, TypeSpec),
diff --git a/compiler/hlds_args.m b/compiler/hlds_args.m
index 8d9a14c2d..ffb70b94f 100644
--- a/compiler/hlds_args.m
+++ b/compiler/hlds_args.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006-2007 The University of Melbourne.
+% Copyright (C) 2006-2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -219,12 +219,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_util.
 :- import_module parse_tree.prog_type.  
-    % Require for apply_partial_map_to_list
-    % XXX that should really live in a different module.
+    % Required for apply_partial_map_to_list.
+    % XXX That should really live in a different module.
 
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/hlds_clauses.m b/compiler/hlds_clauses.m
index 7ec175502..76bf2ef52 100644
--- a/compiler/hlds_clauses.m
+++ b/compiler/hlds_clauses.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1996-2007, 2009 The University of Melbourne.
+% Copyright (C) 1996-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -237,11 +237,11 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_util.
 
 :- import_module int.
 :- import_module map.
+:- import_module require.
 :- import_module term.
 :- import_module varset.
 
diff --git a/compiler/hlds_code_util.m b/compiler/hlds_code_util.m
index e3644a9f3..edfac6e1d 100644
--- a/compiler/hlds_code_util.m
+++ b/compiler/hlds_code_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002-2009 The University of Melbourne.
+% Copyright (C) 2002-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -48,7 +48,6 @@
 :- import_module check_hlds.mode_util.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -57,6 +56,7 @@
 :- import_module bool.
 :- import_module char.
 :- import_module map.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/hlds_data.m b/compiler/hlds_data.m
index 74268966a..82e6460b3 100644
--- a/compiler/hlds_data.m
+++ b/compiler/hlds_data.m
@@ -34,13 +34,13 @@
 :- implementation.
 
 :- import_module check_hlds.type_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type_subst.
 :- import_module parse_tree.prog_util.
 
 :- import_module cord.
 :- import_module int.
 :- import_module multi_map.
+:- import_module require.
 :- import_module svmap.
 :- import_module varset.
 
diff --git a/compiler/hlds_error_util.m b/compiler/hlds_error_util.m
index 92faed510..16cbbde45 100644
--- a/compiler/hlds_error_util.m
+++ b/compiler/hlds_error_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2007, 2009 The University of Melbourne.
+% Copyright (C) 1997-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -116,7 +116,6 @@
 
 :- import_module hlds.special_pred.
 :- import_module mdbcomp.prim_data.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_mode.
 :- import_module parse_tree.prog_out.
@@ -125,6 +124,7 @@
 :- import_module int.
 :- import_module string.
 :- import_module list.
+:- import_module require.
 :- import_module term.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/hlds_goal.m b/compiler/hlds_goal.m
index ce418e9d2..96c680c2a 100644
--- a/compiler/hlds_goal.m
+++ b/compiler/hlds_goal.m
@@ -1785,7 +1785,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.builtin_lib_types.
 :- import_module parse_tree.prog_mode.
 :- import_module parse_tree.prog_type.
@@ -1793,6 +1792,7 @@
 :- import_module assoc_list.
 :- import_module cord.
 :- import_module map.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module svvarset.
diff --git a/compiler/hlds_llds.m b/compiler/hlds_llds.m
index 78da26e99..455e08bf4 100644
--- a/compiler/hlds_llds.m
+++ b/compiler/hlds_llds.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002-2007, 2009 The University of Melbourne.
+% Copyright (C) 2002-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -278,11 +278,11 @@
 :- implementation.
 
 :- import_module hlds.goal_util.
-:- import_module libs.compiler_util.
 
 :- import_module assoc_list.
 :- import_module list.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module varset.
 
diff --git a/compiler/hlds_module.m b/compiler/hlds_module.m
index 556618908..f3f986f49 100644
--- a/compiler/hlds_module.m
+++ b/compiler/hlds_module.m
@@ -661,13 +661,13 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.file_names.
 :- import_module parse_tree.module_imports.
 :- import_module parse_tree.prog_util.
 
 :- import_module assoc_list.
 :- import_module counter.
+:- import_module require.
 
 :- pred module_info_get_lambdas_per_context(module_info::in,
     map(prog_context, counter)::out) is det.
diff --git a/compiler/hlds_out_mode.m b/compiler/hlds_out_mode.m
index 2e3aaa554..907ce7de0 100644
--- a/compiler/hlds_out_mode.m
+++ b/compiler/hlds_out_mode.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2009 The University of Melbourne.
+% Copyright (C) 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -72,13 +72,13 @@
 
 :- import_module check_hlds.mode_util.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_io_util.
 :- import_module parse_tree.prog_util.
 
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/hlds_out_module.m b/compiler/hlds_out_module.m
index e158a1653..123ca4acf 100644
--- a/compiler/hlds_out_module.m
+++ b/compiler/hlds_out_module.m
@@ -45,7 +45,6 @@
 :- import_module hlds.hlds_out.hlds_out_goal.
 :- import_module hlds.hlds_out.hlds_out_pred.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.mercury_to_mercury.
@@ -56,6 +55,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/hlds_out_pred.m b/compiler/hlds_out_pred.m
index 0eaa9fa9b..56b348ebf 100644
--- a/compiler/hlds_out_pred.m
+++ b/compiler/hlds_out_pred.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2009 The University of Melbourne.
+% Copyright (C) 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -78,7 +78,6 @@
 :- import_module hlds.hlds_out.hlds_out_goal.
 :- import_module hlds.hlds_out.hlds_out_mode.
 :- import_module hlds.hlds_rtti.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.program_representation.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_ctgc.
@@ -90,6 +89,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/hlds_pred.m b/compiler/hlds_pred.m
index 964f9e447..08d79163c 100644
--- a/compiler/hlds_pred.m
+++ b/compiler/hlds_pred.m
@@ -47,19 +47,24 @@
 
 :- implementation.
 
+:- import_module backend_libs.
+:- import_module backend_libs.builtin_ops.
 :- import_module check_hlds.inst_match.
+:- import_module check_hlds.mode_errors.
 :- import_module check_hlds.mode_util.
 :- import_module check_hlds.type_util.
 :- import_module hlds.goal_form.
 :- import_module hlds.goal_util.
 :- import_module hlds.hlds_args.
 :- import_module hlds.hlds_rtti.
-:- import_module libs.compiler_util.
+:- import_module hlds.special_pred.
 :- import_module libs.options.
+:- import_module mdbcomp.program_representation.
 :- import_module parse_tree.prog_type.
 :- import_module parse_tree.prog_util.
 
 :- import_module int.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 :- import_module unit.
@@ -2215,9 +2220,6 @@ attribute_list_to_attributes(Attributes, Attributes).
 
 :- implementation.
 
-:- import_module check_hlds.mode_errors.
-:- import_module mdbcomp.program_representation.
-
 :- type proc_info
     --->    proc_info(
                 % The context of the `:- mode' decl (or the context of the
@@ -3114,10 +3116,6 @@ pred_info_is_field_access_function(ModuleInfo, PredInfo) :-
 
 :- implementation.
 
-:- import_module backend_libs.
-:- import_module backend_libs.builtin_ops.
-:- import_module hlds.special_pred.
-
 pred_info_is_builtin(PredInfo) :-
     ModuleName = pred_info_module(PredInfo),
     PredName = pred_info_name(PredInfo),
diff --git a/compiler/hlds_rtti.m b/compiler/hlds_rtti.m
index 961e64c8e..85250d86c 100644
--- a/compiler/hlds_rtti.m
+++ b/compiler/hlds_rtti.m
@@ -332,12 +332,12 @@
 :- implementation.
 
 :- import_module check_hlds.mode_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type.
 :- import_module parse_tree.prog_type_subst.
 
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set_tree234.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/ilasm.m b/compiler/ilasm.m
index 0275a6431..ffd7d7f6c 100644
--- a/compiler/ilasm.m
+++ b/compiler/ilasm.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1999-2007, 2009 The University of Melbourne.
+% Copyright (C) 1999-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -343,7 +343,6 @@
 :- implementation.
 
 :- import_module backend_libs.c_util. % for output_float_literal
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 
 :- import_module char.
@@ -351,6 +350,7 @@
 :- import_module int.
 :- import_module pair.
 :- import_module pprint.
+:- import_module require.
 :- import_module string.
 :- import_module term_io.
 :- import_module varset.
diff --git a/compiler/ilds.m b/compiler/ilds.m
index b3e5bba16..f577100fd 100644
--- a/compiler/ilds.m
+++ b/compiler/ilds.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1999-2006 The University of Melbourne.
+% Copyright (C) 1999-2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -437,9 +437,8 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module int.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/implementation_defined_literals.m b/compiler/implementation_defined_literals.m
index 545c82855..bc72a2021 100644
--- a/compiler/implementation_defined_literals.m
+++ b/compiler/implementation_defined_literals.m
@@ -35,7 +35,6 @@
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.hlds_pred.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.handle_options.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
@@ -44,6 +43,7 @@
 
 :- import_module list.
 :- import_module map.
+:- import_module require.
 :- import_module term.
 
 :- type subst_literals_info
diff --git a/compiler/inlining.m b/compiler/inlining.m
index 9a46529b0..b3d5b83c3 100644
--- a/compiler/inlining.m
+++ b/compiler/inlining.m
@@ -153,7 +153,6 @@
 :- import_module hlds.goal_util.
 :- import_module hlds.passes_aux.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module libs.trace_params.
@@ -171,6 +170,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svset.
 :- import_module term.
diff --git a/compiler/inst_graph.m b/compiler/inst_graph.m
index cde987a23..71f6ff003 100644
--- a/compiler/inst_graph.m
+++ b/compiler/inst_graph.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001-2007, 2009 The University of Melbourne.
+% Copyright (C) 2001-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -187,8 +187,8 @@
 
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
-:- import_module libs.compiler_util.
 
+:- import_module require.
 :- import_module set.
 :- import_module term.
 :- import_module term_io.
diff --git a/compiler/inst_match.m b/compiler/inst_match.m
index 51bac5445..4eb3730fa 100644
--- a/compiler/inst_match.m
+++ b/compiler/inst_match.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1995-1998, 2000-2009 The University of Melbourne.
+% Copyright (C) 1995-1998, 2000-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -319,8 +319,6 @@
 :- import_module check_hlds.inst_util.
 :- import_module check_hlds.mode_util.
 :- import_module check_hlds.type_util.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_data.
@@ -331,6 +329,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module set_tree234.
 :- import_module svset.
diff --git a/compiler/inst_util.m b/compiler/inst_util.m
index 2adf1655e..6cfa7b0df 100644
--- a/compiler/inst_util.m
+++ b/compiler/inst_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2009 The University of Melbourne.
+% Copyright (C) 1997-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -152,8 +152,6 @@
 :- import_module check_hlds.mode_util.
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_data.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_mode.
@@ -163,6 +161,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module svset.
diff --git a/compiler/instmap.m b/compiler/instmap.m
index 7468fb536..eb111ac16 100644
--- a/compiler/instmap.m
+++ b/compiler/instmap.m
@@ -359,13 +359,13 @@
 :- import_module check_hlds.inst_util.
 :- import_module check_hlds.mode_util.
 :- import_module check_hlds.type_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 
 :- import_module bool.
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module std_util.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/intermod.m b/compiler/intermod.m
index 54864a434..107335086 100644
--- a/compiler/intermod.m
+++ b/compiler/intermod.m
@@ -113,7 +113,6 @@
 :- import_module hlds.hlds_pred.
 :- import_module hlds.pred_table.
 :- import_module hlds.special_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -136,6 +135,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/interval.m b/compiler/interval.m
index 5ea55b5e3..930a17d38 100644
--- a/compiler/interval.m
+++ b/compiler/interval.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002-2009 The University of Melbourne.
+% Copyright (C) 2002-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -192,13 +192,12 @@
 :- import_module hlds.goal_util.
 :- import_module hlds.hlds_llds.
 :- import_module hlds.instmap.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.
 :- import_module ll_backend.call_gen.
 
 :- import_module assoc_list.
 :- import_module pair.
+:- import_module require.
 :- import_module svmap.
 :- import_module svset.
 :- import_module svvarset.
diff --git a/compiler/ite_gen.m b/compiler/ite_gen.m
index d12456b2b..c8f259bd5 100644
--- a/compiler/ite_gen.m
+++ b/compiler/ite_gen.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1994-2009 The University of Melbourne.
+% Copyright (C) 1994-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -43,7 +43,6 @@
 :- import_module hlds.hlds_module.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.code_gen.
@@ -64,6 +63,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/jumpopt.m b/compiler/jumpopt.m
index 79d8d2cf4..d6dcb6fda 100644
--- a/compiler/jumpopt.m
+++ b/compiler/jumpopt.m
@@ -64,7 +64,6 @@
 :- implementation.
 
 :- import_module backend_libs.builtin_ops.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.code_util.
 :- import_module ll_backend.opt_util.
 :- import_module parse_tree.prog_data.
@@ -72,6 +71,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 
diff --git a/compiler/lambda.m b/compiler/lambda.m
index 7c3d970b0..7ee9451cd 100644
--- a/compiler/lambda.m
+++ b/compiler/lambda.m
@@ -92,7 +92,6 @@
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -109,6 +108,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/layout_out.m b/compiler/layout_out.m
index 26a08448e..adaee722d 100644
--- a/compiler/layout_out.m
+++ b/compiler/layout_out.m
@@ -175,7 +175,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.special_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.trace_params.
 :- import_module ll_backend.llds_out.llds_out_code_addr.
 :- import_module ll_backend.llds_out.llds_out_data.
@@ -188,6 +187,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module varset.
 
diff --git a/compiler/lco.m b/compiler/lco.m
index 14e401ae1..24b6bae84 100644
--- a/compiler/lco.m
+++ b/compiler/lco.m
@@ -178,7 +178,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -196,6 +195,7 @@
 :- import_module multi_map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svbag.
diff --git a/compiler/live_vars.m b/compiler/live_vars.m
index 8dd3c4ae1..59b735dbe 100644
--- a/compiler/live_vars.m
+++ b/compiler/live_vars.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2008 The University of Melbourne.
+% Copyright (C) 1994-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -66,11 +66,11 @@
 :- import_module hlds.hlds_llds.
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/livemap.m b/compiler/livemap.m
index 698d60cf6..161bec24b 100644
--- a/compiler/livemap.m
+++ b/compiler/livemap.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1995-2007, 2009 The University of Melbourne.
+% Copyright (C) 1995-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -40,12 +40,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.opt_util.
 :- import_module parse_tree.prog_data.
 
 :- import_module bool.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svset.
 
diff --git a/compiler/liveness.m b/compiler/liveness.m
index fce0ccee8..a83bf9ee0 100644
--- a/compiler/liveness.m
+++ b/compiler/liveness.m
@@ -197,7 +197,6 @@
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.instmap.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module libs.trace_params.
@@ -211,6 +210,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svset.
 :- import_module term.
diff --git a/compiler/llds.m b/compiler/llds.m
index c35fde7b1..ab69b209d 100644
--- a/compiler/llds.m
+++ b/compiler/llds.m
@@ -1432,9 +1432,8 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module int.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/llds_out_data.m b/compiler/llds_out_data.m
index 4515922e4..6ab31245c 100644
--- a/compiler/llds_out_data.m
+++ b/compiler/llds_out_data.m
@@ -1,7 +1,7 @@
 %----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %----------------------------------------------------------------------------%
-% Copyright (C) 2009 The University of Melbourne.
+% Copyright (C) 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %----------------------------------------------------------------------------%
@@ -151,7 +151,6 @@
 :- import_module backend_libs.c_util.
 :- import_module backend_libs.name_mangle.
 :- import_module backend_libs.rtti.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.layout_out.
 :- import_module ll_backend.llds_out.llds_out_code_addr.
 :- import_module ll_backend.rtti_out.
@@ -161,6 +160,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module string.
 
 %----------------------------------------------------------------------------%
diff --git a/compiler/llds_out_file.m b/compiler/llds_out_file.m
index 5992a53a2..51f6f51e2 100644
--- a/compiler/llds_out_file.m
+++ b/compiler/llds_out_file.m
@@ -1,7 +1,7 @@
 %----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %----------------------------------------------------------------------------%
-% Copyright (C) 2009 The University of Melbourne.
+% Copyright (C) 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %----------------------------------------------------------------------------%
@@ -18,7 +18,6 @@
 :- module ll_backend.llds_out.llds_out_file.
 :- interface.
 
-% :- import_module hlds.hlds_llds.
 :- import_module libs.globals.
 :- import_module ll_backend.llds.
 
@@ -73,7 +72,6 @@
 :- import_module backend_libs.rtti.
 :- import_module hlds.hlds_module.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module libs.trace_params.
 :- import_module ll_backend.layout.
@@ -97,6 +95,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module set_tree234.
 :- import_module string.
diff --git a/compiler/llds_out_global.m b/compiler/llds_out_global.m
index f2943435f..9e05ebebd 100644
--- a/compiler/llds_out_global.m
+++ b/compiler/llds_out_global.m
@@ -1,7 +1,7 @@
 %----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %----------------------------------------------------------------------------%
-% Copyright (C) 2009 The University of Melbourne.
+% Copyright (C) 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %----------------------------------------------------------------------------%
@@ -54,7 +54,6 @@
 :- import_module backend_libs.name_mangle.
 :- import_module backend_libs.rtti.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.llds_out.llds_out_data.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_data.
@@ -64,6 +63,7 @@
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 
 %----------------------------------------------------------------------------%
diff --git a/compiler/llds_out_instr.m b/compiler/llds_out_instr.m
index 21cd7ad6b..8599cf99a 100644
--- a/compiler/llds_out_instr.m
+++ b/compiler/llds_out_instr.m
@@ -1,7 +1,7 @@
 %----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %----------------------------------------------------------------------------%
-% Copyright (C) 2009 The University of Melbourne.
+% Copyright (C) 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %----------------------------------------------------------------------------%
@@ -60,7 +60,6 @@
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.layout.
 :- import_module ll_backend.layout_out.
 :- import_module ll_backend.llds_out.llds_out_code_addr.
@@ -77,6 +76,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/llds_to_x86_64.m b/compiler/llds_to_x86_64.m
index ed503098f..241677a1a 100644
--- a/compiler/llds_to_x86_64.m
+++ b/compiler/llds_to_x86_64.m
@@ -49,7 +49,6 @@
 
 :- import_module backend_libs.builtin_ops.
 :- import_module backend_libs.name_mangle.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.llds_out.
 :- import_module ll_backend.llds_out.llds_out_code_addr.
 :- import_module ll_backend.x86_64_out.
@@ -60,6 +59,7 @@
 :- import_module int.
 :- import_module io.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/lookup_switch.m b/compiler/lookup_switch.m
index e168a90a5..c1b465ff2 100644
--- a/compiler/lookup_switch.m
+++ b/compiler/lookup_switch.m
@@ -170,7 +170,6 @@
 :- import_module check_hlds.type_util.
 :- import_module hlds.code_model.
 :- import_module hlds.goal_form.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.continuation_info.
@@ -184,6 +183,7 @@
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module std_util.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/lookup_util.m b/compiler/lookup_util.m
index 082895953..39db6e659 100644
--- a/compiler/lookup_util.m
+++ b/compiler/lookup_util.m
@@ -82,7 +82,6 @@
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_module.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module ll_backend.code_gen.
 :- import_module ll_backend.exprn_aux.
@@ -92,6 +91,7 @@
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 
 figure_out_output_vars(CI, GoalInfo, OutVars) :-
     InstMapDelta = goal_info_get_instmap_delta(GoalInfo),
diff --git a/compiler/loop_inv.m b/compiler/loop_inv.m
index ac5f592cd..1595f9716 100644
--- a/compiler/loop_inv.m
+++ b/compiler/loop_inv.m
@@ -125,7 +125,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.instmap.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_util.
@@ -136,6 +135,7 @@
 :- import_module list.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/lp.m b/compiler/lp.m
index b61ab5023..e71e47903 100644
--- a/compiler/lp.m
+++ b/compiler/lp.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997,2002-2007 The University of Melbourne.
+% Copyright (C) 1997,2002-2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -88,12 +88,11 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module bool.
 :- import_module float.
 :- import_module int.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
@@ -104,15 +103,16 @@
 %-----------------------------------------------------------------------------%
 
 :- type lp_info
-    --->    lp(
-                varset  :: varset,
-                urs_map :: map(var, pair(var)),
-                            % Map from variables with URS to the
-                            % corresponding pair of variables that
-                            % represent that variable in the standard
-                            % form (x = x' - x'', x', x'' >= 0).
-                slack_vars :: list(var),      % slack variables
-                artificial_vars :: list(var)  % artificial variables
+    --->    lp_info(
+                lpi_varset                  :: varset,
+
+                % Map from variables with URS to the corresponding pair
+                % of variables that represent that variable in the standard
+                % form (x = x' - x'', x', x'' >= 0).
+                lpi_urs_map                 :: map(var, pair(var)),
+
+                lpi_slack_vars              :: list(var),
+                lpi_art_vars                :: list(var)
             ).
 
 %-----------------------------------------------------------------------------%
@@ -152,7 +152,7 @@ lp_solve_2(Eqns0, Dir, Obj0, Result, !Info, !IO) :-
     ),
     simplify_coeffs(Obj1, Obj2),
 
-    get_urs_vars(URS, !.Info, _),
+    get_urs_vars(!.Info, URS),
     expand_urs_vars(Obj2, URS, Obj),
     list.length(Eqns, Rows),
     collect_vars(Eqns, Obj, Vars),
@@ -160,7 +160,7 @@ lp_solve_2(Eqns0, Dir, Obj0, Result, !Info, !IO) :-
     list.length(VarList, Cols),
     map.init(VarNums0),
     number_vars(VarList, 0, VarNums0, VarNums),
-    get_art_vars(ArtVars, !Info),
+    get_art_vars(!.Info, ArtVars),
     some [!Tableau] (
         init_tableau(Rows, Cols, VarNums, URS, !:Tableau),
         insert_equations(Eqns, 1, Cols, VarNums, !Tableau),
@@ -287,7 +287,7 @@ standardize_equation(Eqn0, Eqn, !Info) :-
         new_slack_var(Var, !Info),
         Coeffs = [Var - 1.0 | Coeffs0],
         simplify_eq(eqn(Coeffs, (=<), Const0), Eqn1),
-        get_urs_vars(URS, !Info),
+        get_urs_vars(!.Info, URS),
         expand_urs_vars_e(Eqn1, URS, Eqn)
     ).
 
@@ -300,7 +300,7 @@ standardize_equation(Eqn0, Eqn, !Info) :-
         new_art_var(Var, !Info),
         Coeffs = [Var - 1.0 | Coeffs0],
         simplify_eq(eqn(Coeffs, (=<), Const0), Eqn1),
-        get_urs_vars(URS, !Info),
+        get_urs_vars(!.Info, URS),
         expand_urs_vars_e(Eqn1, URS, Eqn)
     ).
 
@@ -314,7 +314,7 @@ standardize_equation(Eqn0, Eqn, !Info) :-
         new_art_var(AVar, !Info),
         Coeffs = [SVar - (-1.0), AVar - (1.0) | Coeffs0],
         simplify_eq(eqn(Coeffs, (>=), Const0), Eqn1),
-        get_urs_vars(URS, !Info),
+        get_urs_vars(!.Info, URS),
         expand_urs_vars_e(Eqn1, URS, Eqn)
     ).
 
@@ -603,9 +603,7 @@ fix_basis_and_rem_cols([V | Vs], !Tableau) :-
         )
     ),
     solutions.aggregate(all_rows(!.Tableau), BasisAgg, [], Res),
-    (
-        Res = [1.0 - Row]
-    ->
+    ( Res = [1.0 - Row] ->
         PivGoal = (pred(Col1::out) is nondet :-
             all_cols(!.Tableau, Col1),
             Col \= Col1,
@@ -630,7 +628,8 @@ fix_basis_and_rem_cols([V | Vs], !Tableau) :-
 
 %-----------------------------------------------------------------------------%
 
-:- type cell ---> cell(int, int).
+:- type cell
+    --->    cell(int, int).
 
 :- pred pivot(int::in, int::in, tableau::in, tableau::out) is det.
 
@@ -686,15 +685,15 @@ row_op(Scale, From, To, !Tableau) :-
 %-----------------------------------------------------------------------------%
 
 :- type tableau
-    ---> tableau(
-        rows         :: int,
-        cols         :: int,
-        var_nums     :: map(var, int),
-        urs_vars     :: map(var, pair(var)),
-        shunned_rows :: list(int),
-        shunned_cols :: list(int),
-        cells        :: map(pair(int), float)
-    ).
+    --->    tableau(
+                rows         :: int,
+                cols         :: int,
+                var_nums     :: map(var, int),
+                urs_vars     :: map(var, pair(var)),
+                shunned_rows :: list(int),
+                shunned_cols :: list(int),
+                cells        :: map(pair(int), float)
+            ).
 
 :- pred init_tableau(int::in, int::in, map(var, int)::in,
         map(var, pair(var))::in, tableau::out) is det.
@@ -832,75 +831,54 @@ lp_info_init(Varset0, URSVars, LPInfo) :-
     ),
     map.init(URSMap0),
     list.foldl(Introduce, URSVars, Varset0 - URSMap0, Varset - URSMap),
-    LPInfo = lp(Varset, URSMap, [], []).
+    LPInfo = lp_info(Varset, URSMap, [], []).
 
 :- pred new_slack_var(var::out, lp_info::in, lp_info::out) is det.
 
 new_slack_var(Var, !Info) :-
     some [!Varset] (
-        get_varset(!:Varset, !Info),
+        get_varset(!.Info, !:Varset),
         svvarset.new_var(Var, !Varset),
         set_varset(!.Varset, !Info)
     ),
-    get_slack_vars(Vars, !Info),
+    get_slack_vars(!.Info, Vars),
     set_slack_vars([Var | Vars], !Info).
 
 :- pred new_art_var(var::out, lp_info::in, lp_info::out) is det.
 
 new_art_var(Var, !Info) :-
     some [!Varset] (
-        get_varset(!:Varset, !Info),
+        get_varset(!.Info, !:Varset),
         svvarset.new_var(Var, !Varset),
         set_varset(!.Varset, !Info)
     ),
-    get_art_vars(Vars, !Info),
+    get_art_vars(!.Info, Vars),
     set_art_vars([Var | Vars], !Info).
 
-:- pred get_varset(varset::out, lp_info::in, lp_info::out) is det.
+:- pred get_varset(lp_info::in, varset::out) is det.
+:- pred get_urs_vars(lp_info::in, map(var, pair(var))::out) is det.
+:- pred get_slack_vars(lp_info::in, list(var)::out) is det.
+:- pred get_art_vars(lp_info::in, list(var)::out) is det.
 
-get_varset(Varset, Info, Info) :-
-    Info = lp(Varset, _URSVars, _Slack, _Art).
+get_varset(Info, Info ^ lpi_varset).
+get_urs_vars(Info, Info ^ lpi_urs_map).
+get_slack_vars(Info, Info ^ lpi_slack_vars).
+get_art_vars(Info, Info ^ lpi_art_vars).
 
 :- pred set_varset(varset::in, lp_info::in, lp_info::out) is det.
-
-set_varset(Varset, Info0, Info) :-
-    Info0 = lp(_Varset, URSVars, Slack, Art),
-    Info  = lp(Varset, URSVars, Slack, Art).
-
-:- pred get_urs_vars(map(var, pair(var))::out, lp_info::in, lp_info::out)
-    is det.
-
-get_urs_vars(URSVars, Info, Info) :-
-    Info = lp(_Varset, URSVars, _Slack, _Art).
-
 :- pred set_urs_vars(map(var, pair(var))::in, lp_info::in, lp_info::out)
     is det.
-
-set_urs_vars(URSVars, Info0, Info) :-
-    Info0 = lp(Varset, _URSVars, Slack, Art),
-    Info  = lp(Varset, URSVars, Slack, Art).
-
-:- pred get_slack_vars(list(var)::out, lp_info::in, lp_info::out) is det.
-
-get_slack_vars(Slack, Info, Info) :-
-    Info = lp(_Varset, _URSVars, Slack, _Art).
-
 :- pred set_slack_vars(list(var)::in, lp_info::in, lp_info::out) is det.
-
-set_slack_vars(Slack, Info0, Info) :-
-    Info0 = lp(Varset, URSVars, _Slack, Art),
-    Info  = lp(Varset, URSVars, Slack, Art).
-
-:- pred get_art_vars(list(var)::out, lp_info::in, lp_info::out) is det.
-
-get_art_vars(Art, Info, Info) :-
-    Info = lp(_Varset, _URSVars, _Slack, Art).
-
 :- pred set_art_vars(list(var)::in, lp_info::in, lp_info::out) is det.
 
-set_art_vars(Art, Info0, Info) :-
-    Info0 = lp(Varset, URSVars, Slack, _Art),
-    Info  = lp(Varset, URSVars, Slack, Art).
+set_varset(Varset, !Info) :-
+    !Info ^ lpi_varset := Varset.
+set_urs_vars(URSVars, !Info) :-
+    !Info ^ lpi_urs_map := URSVars.
+set_slack_vars(Slack, !Info) :-
+    !Info ^ lpi_slack_vars := Slack.
+set_art_vars(Art, !Info) :-
+    !Info ^ lpi_art_vars := Art.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/lp_rational.m b/compiler/lp_rational.m
index a0ba470a3..d317d0814 100644
--- a/compiler/lp_rational.m
+++ b/compiler/lp_rational.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2002, 2005-2007, 2009 The University of Melbourne.
+% Copyright (C) 1997-2002, 2005-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -177,7 +177,7 @@
 
 %-----------------------------------------------------------------------------%
 %
-% Bounding boxes and other approximations
+% Bounding boxes and other approximations.
 %
     % Approximate the solution space of a set of constraints using
     % a bounding box. If the system is inconsistent then the resulting
@@ -193,7 +193,7 @@
 
 %-----------------------------------------------------------------------------%
 %
-% Linear solver
+% Linear solver.
 %
 
 :- type objective == lp_terms.
@@ -223,7 +223,7 @@
 
 %-----------------------------------------------------------------------------%
 %
-% Projection
+% Projection.
 %
 
 :- type projection_result
@@ -260,7 +260,7 @@
 
 %-----------------------------------------------------------------------------%
 %
-% Entailment
+% Entailment.
 %
 
 :- type entailment_result
@@ -291,7 +291,7 @@
 
 %-----------------------------------------------------------------------------%
 %
-% Stuff for intermodule optimization
+% Stuff for intermodule optimization.
 %
 
     % A function that converts an lp_var into a string.
@@ -306,7 +306,7 @@
 
 %-----------------------------------------------------------------------------%
 %
-% Debugging predicates
+% Debugging predicates.
 %
 
     % Print out the constraints using the names in the varset.  If the
@@ -328,11 +328,10 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module assoc_list.
 :- import_module bool.
 :- import_module int.
+:- import_module require.
 :- import_module solutions.
 :- import_module string.
 :- import_module svmap.
@@ -340,7 +339,7 @@
 
 %-----------------------------------------------------------------------------%
 %
-% Constraints
+% Constraints.
 %
 
     % The following properties should hold for each constraint:
@@ -761,31 +760,31 @@ nonneg_box(VarsToIgnore, Constraints) = NonNegConstraints :-
 % XXX Most of this came from lp.m.  We should try to remove a lot of
 % nondeterminism here.
 
-:- type lp_info
-    --->    lp(
-                varset     :: lp_varset,
-                slack_vars :: lp_vars,  % - slack variables.
-                art_vars   :: lp_vars   % - artificial variables.
+:- type lpr_info
+    --->    lpr_info(
+                lpr_varset     :: lp_varset,
+                lpr_slack_vars :: lp_vars,
+                lpr_art_vars   :: lp_vars
             ).
 
 lp_rational.solve(Constraints, Direction, Objective, Varset) = Result :-
-    Info0 = lp_info_init(Varset),
+    Info0 = lpr_info_init(Varset),
     solve_2(Constraints, Direction, Objective, Result, Info0, _).
 
-    % solve_2(Eqns, Dir, Obj, Res, LPInfo0, LPInfo) takes a list
+    % solve_2(Eqns, Dir, Obj, Res, LPRInfo0, LPRInfo) takes a list
     % of inequalities `Eqns', a direction for optimization `Dir', an
-    % objective function `Obj' and an lp_info structure `LPInfo0'.
+    % objective function `Obj' and an lpr_info structure `LPRInfo0'.
     % See inline comments for details on the algorithm.
     %
 :- pred solve_2(constraints::in, direction::in, objective::in,
-    lp_result::out, lp_info::in, lp_info::out) is det.
+    lp_result::out, lpr_info::in, lpr_info::out) is det.
 
-solve_2(!.Constraints, Direction, !.Objective, Result, !LPInfo) :-
+solve_2(!.Constraints, Direction, !.Objective, Result, !LPRInfo) :-
     % Simplify the inequalities and convert them to standard form by
     % introducing slack/artificial variables.
 
     Obj = !.Objective,
-    lp_standardize_constraints(!Constraints, !LPInfo),
+    lp_standardize_constraints(!Constraints, !LPRInfo),
 
     % If we are maximizing the objective function then we need
     % to negate all the coefficients in the objective.
@@ -801,7 +800,7 @@ solve_2(!.Constraints, Direction, !.Objective, Result, !LPInfo) :-
     VarList = set.to_sorted_list(Vars),
     Columns = list.length(VarList),
     VarNums = number_vars(VarList, 0),
-    ArtVars = !.LPInfo ^ art_vars,
+    ArtVars = !.LPRInfo ^ lpr_art_vars,
     Tableau0 = init_tableau(Rows, Columns, VarNums),
     insert_constraints(!.Constraints, 1, Columns, VarNums, Tableau0, Tableau),
     (
@@ -880,43 +879,43 @@ two_phase(Obj0, Obj, ArtVars, VarNums, !.Tableau) = Result :-
 %-----------------------------------------------------------------------------%
 
 :- pred lp_standardize_constraints(constraints::in, constraints::out,
-    lp_info::in, lp_info::out) is det.
+    lpr_info::in, lpr_info::out) is det.
 
-lp_standardize_constraints(!Constraints, !LPInfo) :-
-    list.map_foldl(lp_standardize_constraint, !Constraints, !LPInfo).
+lp_standardize_constraints(!Constraints, !LPRInfo) :-
+    list.map_foldl(lp_standardize_constraint, !Constraints, !LPRInfo).
 
     % standardize_constraint performs the following operations on a
     % constraint:
-    %   - ensures the constant is >= 0
-    %       (multiplying by -1 if necessary)
+    %
+    %   - ensures the constant is >= 0 (multiplying by -1 if necessary)
     %   - introduces slack and artificial variables
     %
 :- pred lp_standardize_constraint(constraint::in, constraint::out,
-    lp_info::in, lp_info::out) is det.
+    lpr_info::in, lpr_info::out) is det.
 
-lp_standardize_constraint(Constr0 @ lte(Coeffs, Const), Constr, !LPInfo) :-
+lp_standardize_constraint(Constr0 @ lte(Coeffs, Const), Constr, !LPRInfo) :-
     ( Const < zero ->
         Constr1 = negate_constraint(Constr0),
-        lp_standardize_constraint(Constr1, Constr, !LPInfo)
+        lp_standardize_constraint(Constr1, Constr, !LPRInfo)
     ;
-        new_slack_var(Var, !LPInfo),
+        new_slack_var(Var, !LPRInfo),
         Constr = lte([Var - one | Coeffs], Const)
     ).
-lp_standardize_constraint(Eqn0 @ eq(Coeffs, Const), Eqn, !LPInfo) :-
+lp_standardize_constraint(Eqn0 @ eq(Coeffs, Const), Eqn, !LPRInfo) :-
     ( Const < zero ->
         Eqn1 = negate_constraint(Eqn0),
-        lp_standardize_constraint(Eqn1, Eqn, !LPInfo)
+        lp_standardize_constraint(Eqn1, Eqn, !LPRInfo)
     ;
-        new_art_var(Var, !LPInfo),
+        new_art_var(Var, !LPRInfo),
         Eqn = lte([Var - one | Coeffs], Const)
     ).
-lp_standardize_constraint(Eqn0 @ gte(Coeffs, Const), Eqn, !LPInfo) :-
+lp_standardize_constraint(Eqn0 @ gte(Coeffs, Const), Eqn, !LPRInfo) :-
     ( Const < zero ->
         Eqn1 = negate_constraint(Eqn0),
-        lp_standardize_constraint(Eqn1, Eqn, !LPInfo)
+        lp_standardize_constraint(Eqn1, Eqn, !LPRInfo)
     ;
-        new_slack_var(SVar, !LPInfo),
-        new_art_var(AVar, !LPInfo),
+        new_slack_var(SVar, !LPRInfo),
+        new_art_var(AVar, !LPRInfo),
         Eqn = gte([AVar - one, SVar - (-one) | Coeffs], Const)
     ).
 
@@ -1362,25 +1361,25 @@ get_basis_vars(Tableau) = Vars :-
 
 %-----------------------------------------------------------------------------%
 
-:- func lp_info_init(lp_varset) = lp_info.
+:- func lpr_info_init(lp_varset) = lpr_info.
 
-lp_info_init(Varset) = lp(Varset, [], []).
+lpr_info_init(Varset) = lpr_info(Varset, [], []).
 
-:- pred new_slack_var(lp_var::out, lp_info::in, lp_info::out) is det.
+:- pred new_slack_var(lp_var::out, lpr_info::in, lpr_info::out) is det.
 
-new_slack_var(Var, !LPInfo) :-
-    varset.new_var(!.LPInfo ^ varset, Var, Varset),
-    !:LPInfo = !.LPInfo ^ varset := Varset,
-    Vars = !.LPInfo ^ slack_vars,
-    !:LPInfo = !.LPInfo ^ slack_vars := [Var | Vars].
+new_slack_var(Var, !LPRInfo) :-
+    varset.new_var(!.LPRInfo ^ lpr_varset, Var, Varset),
+    !LPRInfo ^ lpr_varset := Varset,
+    Vars = !.LPRInfo ^ lpr_slack_vars,
+    !LPRInfo ^ lpr_slack_vars := [Var | Vars].
 
-:- pred new_art_var(lp_var::out, lp_info::in, lp_info::out) is det.
+:- pred new_art_var(lp_var::out, lpr_info::in, lpr_info::out) is det.
 
-new_art_var(Var, !LPInfo) :-
-    varset.new_var(!.LPInfo ^ varset, Var, Varset),
-    !:LPInfo = !.LPInfo ^ varset := Varset,
-    Vars = !.LPInfo ^ art_vars,
-    !:LPInfo = !.LPInfo ^ art_vars := [Var | Vars].
+new_art_var(Var, !LPRInfo) :-
+    varset.new_var(!.LPRInfo ^ lpr_varset, Var, Varset),
+    !LPRInfo ^ lpr_varset := Varset,
+    Vars = !.LPRInfo ^ lpr_art_vars,
+    !LPRInfo ^ lpr_art_vars := [Var | Vars].
 
 %-----------------------------------------------------------------------------%
 
@@ -1425,17 +1424,16 @@ between(Min, Max, I) :-
 %-----------------------------------------------------------------------------%
 
 :- type vector
-    ---> vector(
-        label :: set(int),
-            % The vector's label is for redundancy checking
-            % during Fourier elimination - see below.
+    --->    vector(
+                % The vector's label is for redundancy checking
+                % during Fourier elimination - see below.
+                label :: set(int),
 
-        terms :: map(lp_var, coefficient),
-            % A map from each variable in the vector to its
-            % coefficient
+                % A map from each variable in the vector to its coefficient.
+                terms :: map(lp_var, coefficient),
 
-        const :: constant
-    ).
+                const :: constant
+            ).
 
 :- type matrix == list(vector).
 
@@ -1493,7 +1491,7 @@ project(!.Vars @ [_|_], Varset, MaybeThreshold, Constraints0, Result) :-
 
 %-----------------------------------------------------------------------------%
 %
-% Convert each constraint into `=<' form and give each an initial label
+% Convert each constraint into `=<' form and give each an initial label.
 %
 
 :- func constraints_to_matrix(constraints) = matrix.
@@ -1931,10 +1929,10 @@ label_subsumed(VectorA, VectorB) :-
     % previous totals from the total number of constraints.
     %
 :- type coeff_info
-    ---> coeff_info(
-           pos :: int,
-           neg :: int
-    ).
+    --->    coeff_info(
+               pos :: int,
+               neg :: int
+            ).
 
 :- type cc_map == map(lp_var, coeff_info).
 
@@ -1959,9 +1957,10 @@ duffin_heuristic(Vars0 @ [_,_|_], Matrix, TargetVar, Vars) :-
 
 collect_remaining_vars([], _) = [].
 collect_remaining_vars([Var - _ | Rest], TargetVar) = Result :-
-    ( if    Var = TargetVar
-      then  Result = collect_remaining_vars(Rest, TargetVar)
-      else  Result = [ Var | collect_remaining_vars(Rest, TargetVar) ]
+    ( if Var = TargetVar then
+        Result = collect_remaining_vars(Rest, TargetVar)
+      else
+        Result = [Var | collect_remaining_vars(Rest, TargetVar)]
     ).
 
 :- func find_max(list(pair(lp_var, int))) = lp_var.
@@ -1974,14 +1973,16 @@ find_max([Var0 - ExpnNum0 | Vars]) = fst(find_max_2(Vars, Var0 - ExpnNum0)).
 
 find_max_2([], Best) = Best.
 find_max_2([Var1 - ExpnNum1 | Vars], Var0 - ExpnNum0) =
-    ( if    ExpnNum1 < ExpnNum0
-      then  find_max_2(Vars, Var1 - ExpnNum1)
-      else  find_max_2(Vars, Var0 - ExpnNum0)
+    ( if ExpnNum1 < ExpnNum0 then
+        find_max_2(Vars, Var1 - ExpnNum1)
+      else
+        find_max_2(Vars, Var0 - ExpnNum0)
     ).
 
 :- pred relevant(pair(lp_var, int)::in) is semidet.
 
-relevant(Var) :- Var \= _ - 0.
+relevant(Var) :-
+    Var \= _ - 0.
 
     % Given a list of variables and a system of linear inequalities
     % generate the expansion number for each of the variables in the
@@ -2080,16 +2081,18 @@ normalize_vector(Var, !.Terms, !.Constant, !:Terms, !:Constant) :-
 normalize_constraint(Var, Constraint0, Constraint) :-
     lp_rational.deconstruct_constraint(Constraint0, Terms0, Op0, Constant0),
     ( assoc_list.search(Terms0, Var, Coefficient) ->
-        ( if    Coefficient = zero
-          then  unexpected(this_file,
-                    "normalize_constraint/3: zero coefficient constraint.")
-          else  true
+        ( if Coefficient = zero then
+            unexpected(this_file,
+                "normalize_constraint/3: zero coefficient constraint.")
+          else
+            true
         ),
         Terms = list.map((func(V - C) = V - (C / Coefficient)), Terms0),
         Constant = Constant0 / Coefficient,
-        ( if    Coefficient < zero
-          then  Op = negate_operator(Op0)
-          else  Op = Op0
+        ( if Coefficient < zero then
+            Op = negate_operator(Op0)
+          else
+            Op = Op0
         )
     ;
         % In this case the the coefficient of the variable was zero
@@ -2110,13 +2113,14 @@ add_vectors(TermsA, ConstA, TermsB, ConstB, Terms, ConstA + ConstB) :-
     ),
     AddVal = (pred(Var::in, Coeffs0::in, Coeffs::out) is det :-
         NumA = TermsA ^ det_elem(Var),
-        ( if    Coeffs0 ^ elem(Var) = Num1
-          then
-                ( if    NumA + Num1 = zero
-                  then  Coeffs = map.delete(Coeffs0, Var)
-                  else  Coeffs = map.det_update(Coeffs0, Var, NumA + Num1)
-                )
-          else  Coeffs = map.det_insert(Coeffs0, Var, NumA)
+        ( if Coeffs0 ^ elem(Var) = Num1 then
+            ( if NumA + Num1 = zero then
+                Coeffs = map.delete(Coeffs0, Var)
+              else
+                Coeffs = map.det_update(Coeffs0, Var, NumA + Num1)
+            )
+          else
+            Coeffs = map.det_insert(Coeffs0, Var, NumA)
         )
     ),
     solutions.aggregate(IsMapKey, AddVal, TermsB, Terms).
@@ -2130,8 +2134,7 @@ add_vectors(TermsA, ConstA, TermsB, ConstB, Terms, ConstA + ConstB) :-
     % XXX It would be preferable not to use this as it can be very slow.
     %
 remove_some_entailed_constraints(Varset, Constraints0, Constraints) :-
-    remove_some_entailed_constraints_2(Varset, Constraints0, [],
-        Constraints).
+    remove_some_entailed_constraints_2(Varset, Constraints0, [], Constraints).
 
 :- pred remove_some_entailed_constraints_2(lp_varset::in, constraints::in,
     constraints::in, constraints::out) is semidet.
@@ -2161,9 +2164,10 @@ remove_some_entailed_constraints_2(Varset, [E, X | Es], !Constraints) :-
 
 restore_equalities([], []).
 restore_equalities([E0 | Es0], [E | Es])  :-
-    ( if    check_for_equalities(E0, Es0, [], E1, Es1)
-      then  E = E1, Es2 = Es1
-      else  Es2 = Es0, E = E0
+    ( if check_for_equalities(E0, Es0, [], E1, Es1) then
+        E = E1, Es2 = Es1
+      else
+        Es2 = Es0, E = E0
     ),
     restore_equalities(Es2, Es).
 
@@ -2171,9 +2175,7 @@ restore_equalities([E0 | Es0], [E | Es])  :-
     constraint::out, constraints::out) is semidet.
 
 check_for_equalities(Eqn0, [Eqn | Eqns], SoFar, NewEqn, NewEqnSet) :-
-    (
-        opposing_inequalities(Eqn0 @ lte(Coeffs, Constant), Eqn)
-    ->
+    ( opposing_inequalities(Eqn0 @ lte(Coeffs, Constant), Eqn) ->
         NewEqn = standardize_constraint(eq(Coeffs, Constant)),
         NewEqnSet = SoFar ++ Eqns
     ;
@@ -2200,7 +2202,7 @@ opposing_inequalities(lte(TermsA, Const), lte(TermsB, -Const)) :-
 %-----------------------------------------------------------------------------%
 %-----------------------------------------------------------------------------%
 %
-% Entailment test
+% Entailment test.
 %
 
 entailed(Varset, Constraints, lte(Objective, Constant)) = Result :-
@@ -2281,16 +2283,18 @@ get_vars_from_terms([Var - _ | Coeffs], !SetVar) :-
 :- pred write_term(lp_varset::in, lp_term::in, io::di, io::uo) is det.
 
 write_term(Varset, Var - Coefficient, !IO) :-
-    ( if    Coefficient > zero
-      then  io.write_char('+', !IO)
-      else  io.write_char('-', !IO)
+    ( if Coefficient > zero then
+        io.write_char('+', !IO)
+      else
+        io.write_char('-', !IO)
     ),
     io.write_string(" (", !IO),
     Num = abs(numer(Coefficient)),
     io.write_string(int_to_string(Num), !IO),
-    ( if    denom(Coefficient) \= 1
-      then  io.format("/%s", [s(int_to_string(denom(Coefficient)))], !IO)
-      else  true
+    ( if denom(Coefficient) = 1 then
+        true
+      else
+        io.format("/%s", [s(int_to_string(denom(Coefficient)))], !IO)
     ),
     io.write_char(')', !IO),
     io.write_string(varset.lookup_name(Varset, Var), !IO).
@@ -2309,8 +2313,8 @@ write_constraint(Varset, Constr, !IO) :-
     deconstruct_constraint(Constr, Coeffs, Operator, Constant),
     io.write_char('\t', !IO),
     list.foldl(write_constr_term(Varset), Coeffs, !IO),
-    io.format("%s %s\n", [s(operator_to_string(Operator)),
-        s(rat.to_string(Constant))], !IO).
+    io.format("%s %s\n",
+        [s(operator_to_string(Operator)), s(rat.to_string(Constant))], !IO).
 
 :- pred write_constr_term(lp_varset::in, lp_term::in, io::di, io::uo) is det.
 
@@ -2348,9 +2352,8 @@ write_vars_2(Varset, [V | Vs], !IO) :-
 
 var_to_string(Varset, Var) = varset.lookup_name(Varset, Var, "Unnamed").
 
-    % Write out the matrix used during fourier elimination.  If
-    % `Labels' is `yes' then write out the label for each vector
-    % as well.
+    % Write out the matrix used during fourier elimination.
+    % If `Labels' is `yes' then write out the label for each vector as well.
     %
 :- pred write_matrix(lp_varset::in, bool::in, matrix::in, io::di, io::uo)
     is det.
diff --git a/compiler/make.m b/compiler/make.m
index a239e2711..0d52395dc 100644
--- a/compiler/make.m
+++ b/compiler/make.m
@@ -65,7 +65,6 @@
 :- import_module backend_libs.compile_target_code.
 :- import_module hlds.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.handle_options.
 :- import_module libs.md4.
 :- import_module libs.options.
@@ -88,6 +87,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/make.module_target.m b/compiler/make.module_target.m
index f2c046f0a..b1e6a8996 100644
--- a/compiler/make.module_target.m
+++ b/compiler/make.module_target.m
@@ -50,13 +50,13 @@
     --->    foreign_code_file(
                 foreign_language    :: foreign_language,
 
+                % Name of the file produced by the Mercury compiler,
+                % e.g. module_c_code.c.
                 target_file         :: file_name,
-                                    % Name of the file produced by the Mercury
-                                    % compiler, e.g. module_c_code.c.
 
+                % Name of the file produced by the foreign language compiler,
+                % e.g. module_c_code.o.
                 object_file         :: file_name
-                                    % Name of the file produced by the foreign
-                                    % language compiler, e.g. module_c_code.o.
             ).
 
     % Find the foreign code files generated when a module is processed.
@@ -72,7 +72,6 @@
 :- implementation.
 
 :- import_module analysis.
-:- import_module libs.compiler_util.
 :- import_module libs.process_util.
 :- import_module parse_tree.file_names.
 :- import_module parse_tree.module_cmds.
@@ -84,6 +83,7 @@
 
 :- import_module dir.
 :- import_module float.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/make.program_target.m b/compiler/make.program_target.m
index fc4177235..7b749c12c 100644
--- a/compiler/make.program_target.m
+++ b/compiler/make.program_target.m
@@ -40,7 +40,6 @@
 :- implementation.
 
 :- import_module analysis.
-:- import_module libs.compiler_util.
 :- import_module libs.handle_options.
 :- import_module libs.process_util.
 :- import_module parse_tree.file_names.
@@ -56,6 +55,7 @@
 :- import_module digraph.
 :- import_module dir.
 :- import_module getopt_io.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/make.util.m b/compiler/make.util.m
index 3f925bcce..6f8a89617 100644
--- a/compiler/make.util.m
+++ b/compiler/make.util.m
@@ -336,7 +336,6 @@
 :- implementation.
 
 :- import_module analysis.
-:- import_module libs.compiler_util.
 :- import_module libs.handle_options.
 :- import_module libs.process_util.
 :- import_module parse_tree.file_names.
@@ -350,6 +349,7 @@
 :- import_module exception.
 :- import_module getopt_io.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module thread.
 :- import_module thread.channel.
diff --git a/compiler/make_hlds_passes.m b/compiler/make_hlds_passes.m
index 16420b305..5e9a60182 100644
--- a/compiler/make_hlds_passes.m
+++ b/compiler/make_hlds_passes.m
@@ -114,7 +114,6 @@
 :- import_module hlds.make_hlds.qual_info.
 :- import_module hlds.pred_table.
 :- import_module hlds.special_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -129,6 +128,7 @@
 
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/make_tags.m b/compiler/make_tags.m
index a17779da9..f4c155311 100644
--- a/compiler/make_tags.m
+++ b/compiler/make_tags.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-1996, 1998-2009 The University of Melbourne.
+% Copyright (C) 1994-1996, 1998-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -85,7 +85,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.prog_type.
@@ -94,6 +93,7 @@
 :- import_module bool.
 :- import_module int.
 :- import_module map.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/mark_static_terms.m b/compiler/mark_static_terms.m
index f3a15c2c9..7c6f64893 100644
--- a/compiler/mark_static_terms.m
+++ b/compiler/mark_static_terms.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2000-2009 The University of Melbourne.
+% Copyright (C) 2000-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -37,12 +37,12 @@
 :- implementation.
 
 :- import_module hlds.hlds_goal.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set_tree234.
 :- import_module svmap.
 
diff --git a/compiler/matching.m b/compiler/matching.m
index c68539842..c7532ccb2 100644
--- a/compiler/matching.m
+++ b/compiler/matching.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001-2007 The University of Melbourne.
+% Copyright (C) 2001-2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -85,12 +85,6 @@
 
 :- implementation.
 
-% Uncomment if you want to dump performance information into the .err file.
-% :- import_module unsafe.
-
-:- import_module libs.
-:- import_module libs.compiler_util.
-
 :- import_module assoc_list.
 :- import_module int.
 :- import_module io.
@@ -98,6 +92,7 @@
 :- import_module maybe.
 :- import_module pair.
 :- import_module queue.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 :- import_module svmap.
diff --git a/compiler/mcsolver.m b/compiler/mcsolver.m
index 17e0b801f..f858c6712 100644
--- a/compiler/mcsolver.m
+++ b/compiler/mcsolver.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2004-2007, 2009 The University of Melbourne.
+% Copyright (C) 2004-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -123,14 +123,12 @@
 
 :- implementation.
 
-:- import_module libs.
-:- import_module libs.compiler_util.
-
 :- import_module eqvclass.
 :- import_module io.
 :- import_module list.
 :- import_module map.
 :- import_module multi_map.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
@@ -264,7 +262,7 @@ prepare_abstract_constraint(Constraint, !PCs) :-
         ->
             disjunction_of_assignments(DisjOfAssgts, !PCs)
         ;
-            compiler_util.sorry(this_file,
+            sorry(this_file,
                 "Disjuction of constraints - general case.")
         )
     ).
@@ -277,19 +275,14 @@ prepare_abstract_constraint(Constraint, !PCs) :-
 
 prepare_var_constraint(equiv_bool(Var, Value), !PCs) :-
     assign(Var, Value, !PCs).
-
 prepare_var_constraint(equivalent(Vars), !PCs) :-
     equivalent(Vars, !PCs).
-
 prepare_var_constraint(implies(Var1, Var2), !PCs) :-
     implies(Var1, Var2, !PCs).
-
 prepare_var_constraint(equiv_disj(X, Ys), !PCs) :-
     equivalent_to_disjunction(X, Ys, !PCs).
-
 prepare_var_constraint(at_most_one(Vars), !PCs) :-
     at_most_one(Vars, !PCs).
-
 prepare_var_constraint(exactly_one(Vars), !PCs) :-
     exactly_one(Vars, !PCs).
 
diff --git a/compiler/mercury_compile.m b/compiler/mercury_compile.m
index c25a2e4d9..529d69660 100644
--- a/compiler/mercury_compile.m
+++ b/compiler/mercury_compile.m
@@ -95,12 +95,12 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
 :- import_module unit.
 
-
 %-----------------------------------------------------------------------------%
 
 real_main(!IO) :-
diff --git a/compiler/mercury_compile_front_end.m b/compiler/mercury_compile_front_end.m
index b950af5c6..c44bcc897 100644
--- a/compiler/mercury_compile_front_end.m
+++ b/compiler/mercury_compile_front_end.m
@@ -87,7 +87,6 @@
 :- import_module check_hlds.unused_imports.
 :- import_module hlds.hlds_error_util.
 :- import_module hlds.hlds_statistics.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -102,6 +101,7 @@
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/mercury_compile_llds_back_end.m b/compiler/mercury_compile_llds_back_end.m
index 2fc5ffd3e..0eff0afbf 100644
--- a/compiler/mercury_compile_llds_back_end.m
+++ b/compiler/mercury_compile_llds_back_end.m
@@ -58,7 +58,6 @@
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.mark_tail_calls.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -94,6 +93,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 
diff --git a/compiler/mercury_compile_middle_passes.m b/compiler/mercury_compile_middle_passes.m
index 28e752b67..7104a3f49 100644
--- a/compiler/mercury_compile_middle_passes.m
+++ b/compiler/mercury_compile_middle_passes.m
@@ -47,7 +47,6 @@
 :- import_module bytecode_backend.bytecode_gen.
 :- import_module check_hlds.det_analysis.
 :- import_module hlds.hlds_module.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -100,6 +99,7 @@
 :- import_module list.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module univ.
diff --git a/compiler/mercury_compile_mlds_back_end.m b/compiler/mercury_compile_mlds_back_end.m
index a96b8c86e..32572df42 100644
--- a/compiler/mercury_compile_mlds_back_end.m
+++ b/compiler/mercury_compile_mlds_back_end.m
@@ -59,7 +59,6 @@
 :- import_module backend_libs.type_ctor_info.
 :- import_module hlds.arg_info.
 :- import_module hlds.mark_static_terms.            % HLDS -> HLDS
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -86,6 +85,7 @@
 :- import_module getopt_io.
 :- import_module list.
 :- import_module pprint.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/mercury_to_mercury.m b/compiler/mercury_to_mercury.m
index 80e0cd4cf..340c9e2c7 100644
--- a/compiler/mercury_to_mercury.m
+++ b/compiler/mercury_to_mercury.m
@@ -414,7 +414,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module libs.rat.
@@ -430,6 +429,7 @@
 :- import_module map.
 :- import_module pair.
 :- import_module ops.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/middle_rec.m b/compiler/middle_rec.m
index a406fe02d..c3d216c7e 100644
--- a/compiler/middle_rec.m
+++ b/compiler/middle_rec.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1994-2009 The University of Melbourne.
+% Copyright (C) 1994-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -34,7 +34,6 @@
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_llds.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.code_gen.
 :- import_module ll_backend.code_util.
 :- import_module ll_backend.llds_out.
@@ -50,6 +49,7 @@
 :- import_module list.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/ml_call_gen.m b/compiler/ml_call_gen.m
index 144118889..0833353ca 100644
--- a/compiler/ml_call_gen.m
+++ b/compiler/ml_call_gen.m
@@ -92,7 +92,6 @@
 :- import_module check_hlds.mode_util.
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_module.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -105,6 +104,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 
diff --git a/compiler/ml_closure_gen.m b/compiler/ml_closure_gen.m
index ad8283bb7..fadefb207 100644
--- a/compiler/ml_closure_gen.m
+++ b/compiler/ml_closure_gen.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1999-2009 The University of Melbourne.
+% Copyright (C) 1999-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -77,7 +77,6 @@
 :- import_module check_hlds.type_util.
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_module.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.
@@ -100,6 +99,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module set_tree234.
 :- import_module string.
diff --git a/compiler/ml_code_gen.m b/compiler/ml_code_gen.m
index 58230305a..da2ffe419 100644
--- a/compiler/ml_code_gen.m
+++ b/compiler/ml_code_gen.m
@@ -520,7 +520,6 @@
 :- import_module hlds.goal_form.
 :- import_module hlds.hlds_module.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ml_backend.ml_call_gen.
@@ -541,6 +540,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/ml_code_util.m b/compiler/ml_code_util.m
index 0cbd8bcca..263bb7260 100644
--- a/compiler/ml_code_util.m
+++ b/compiler/ml_code_util.m
@@ -556,7 +556,6 @@
 :- import_module check_hlds.polymorphism.
 :- import_module check_hlds.type_util.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.program_representation.
@@ -573,6 +572,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module stack.
 :- import_module string.
diff --git a/compiler/ml_disj_gen.m b/compiler/ml_disj_gen.m
index 5f4245d3a..a171762b7 100644
--- a/compiler/ml_disj_gen.m
+++ b/compiler/ml_disj_gen.m
@@ -123,7 +123,6 @@
 :- import_module backend_libs.builtin_ops.
 :- import_module hlds.goal_form.
 :- import_module hlds.hlds_module.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ml_backend.ml_code_gen.
@@ -135,6 +134,7 @@
 :- import_module bool.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 
 ml_gen_disj(Disjuncts, GoalInfo, CodeModel, Context, Statements, !Info) :-
diff --git a/compiler/ml_elim_nested.m b/compiler/ml_elim_nested.m
index 7b9201434..08eadcf7c 100644
--- a/compiler/ml_elim_nested.m
+++ b/compiler/ml_elim_nested.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1999-2009 The University of Melbourne.
+% Copyright (C) 1999-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -442,7 +442,6 @@
 
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
 :- import_module ml_backend.ml_code_util.
@@ -453,6 +452,7 @@
 :- import_module int.
 :- import_module list.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/ml_foreign_proc_gen.m b/compiler/ml_foreign_proc_gen.m
index 0301fa984..7121a4fc3 100644
--- a/compiler/ml_foreign_proc_gen.m
+++ b/compiler/ml_foreign_proc_gen.m
@@ -53,7 +53,6 @@
 :- import_module check_hlds.mode_util.
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_module.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ml_backend.ml_code_util.
@@ -62,6 +61,7 @@
 :- import_module bool.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/ml_global_data.m b/compiler/ml_global_data.m
index 66709e171..24884d80d 100644
--- a/compiler/ml_global_data.m
+++ b/compiler/ml_global_data.m
@@ -185,11 +185,11 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ml_backend.ml_type_gen.
 
 :- import_module int.
 :- import_module maybe.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 
diff --git a/compiler/ml_lookup_switch.m b/compiler/ml_lookup_switch.m
index 6eac7ff98..8b43f353e 100644
--- a/compiler/ml_lookup_switch.m
+++ b/compiler/ml_lookup_switch.m
@@ -49,7 +49,6 @@
 :- import_module hlds.goal_form.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_module.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module ml_backend.ml_code_gen.
 :- import_module ml_backend.ml_code_util.
@@ -62,6 +61,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/ml_optimize.m b/compiler/ml_optimize.m
index bcca35194..15d9304d5 100644
--- a/compiler/ml_optimize.m
+++ b/compiler/ml_optimize.m
@@ -44,7 +44,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
 :- import_module ml_backend.ml_code_util.
@@ -55,6 +54,7 @@
 :- import_module list.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module std_util.
 :- import_module string.
 
diff --git a/compiler/ml_proc_gen.m b/compiler/ml_proc_gen.m
index 5934a1c17..6bc274ca0 100644
--- a/compiler/ml_proc_gen.m
+++ b/compiler/ml_proc_gen.m
@@ -39,7 +39,6 @@
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -60,6 +59,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module std_util.
 
diff --git a/compiler/ml_simplify_switch.m b/compiler/ml_simplify_switch.m
index 555e3a31d..0efc0d480 100644
--- a/compiler/ml_simplify_switch.m
+++ b/compiler/ml_simplify_switch.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2000-2001, 2003-2009 The University of Melbourne.
+% Copyright (C) 2000-2001, 2003-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -38,7 +38,6 @@
 
 :- import_module backend_libs.builtin_ops.
 :- import_module backend_libs.switch_util.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ml_backend.ml_code_util.
@@ -51,6 +50,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/ml_string_switch.m b/compiler/ml_string_switch.m
index e88bc40de..0fdb9af84 100644
--- a/compiler/ml_string_switch.m
+++ b/compiler/ml_string_switch.m
@@ -42,7 +42,6 @@
 :- import_module backend_libs.switch_util.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_module.
-:- import_module libs.compiler_util.
 :- import_module ml_backend.ml_code_gen.
 :- import_module ml_backend.ml_code_util.
 :- import_module ml_backend.ml_global_data.
@@ -55,6 +54,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module unit.
diff --git a/compiler/ml_switch_gen.m b/compiler/ml_switch_gen.m
index 720ba68e1..320e8104b 100644
--- a/compiler/ml_switch_gen.m
+++ b/compiler/ml_switch_gen.m
@@ -105,7 +105,6 @@
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_module.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module ml_backend.ml_code_gen.
 :- import_module ml_backend.ml_code_util.
@@ -122,6 +121,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/ml_tag_switch.m b/compiler/ml_tag_switch.m
index e37abb160..a65c36ba6 100644
--- a/compiler/ml_tag_switch.m
+++ b/compiler/ml_tag_switch.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2000, 2003-2009 The University of Melbourne.
+% Copyright (C) 2000, 2003-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -42,7 +42,6 @@
 :- import_module backend_libs.rtti.
 :- import_module backend_libs.switch_util.
 :- import_module hlds.hlds_data.
-:- import_module libs.compiler_util.
 :- import_module ml_backend.ml_code_gen.
 :- import_module ml_backend.ml_code_util.
 :- import_module ml_backend.ml_simplify_switch.
@@ -53,6 +52,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module unit.
diff --git a/compiler/ml_type_gen.m b/compiler/ml_type_gen.m
index e2c9b87ff..00bd93e37 100644
--- a/compiler/ml_type_gen.m
+++ b/compiler/ml_type_gen.m
@@ -117,7 +117,6 @@
 
 :- import_module check_hlds.polymorphism.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module ml_backend.ml_code_util.
 :- import_module ml_backend.ml_util.
@@ -131,6 +130,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/ml_unify_gen.m b/compiler/ml_unify_gen.m
index f1a187ef5..35a4e379a 100644
--- a/compiler/ml_unify_gen.m
+++ b/compiler/ml_unify_gen.m
@@ -128,7 +128,6 @@
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -147,6 +146,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/mlds.m b/compiler/mlds.m
index b9cb5b6ac..628954d52 100644
--- a/compiler/mlds.m
+++ b/compiler/mlds.m
@@ -1847,7 +1847,6 @@
 :- import_module backend_libs.foreign.
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_data.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module parse_tree.file_names.
 :- import_module parse_tree.prog_type.
@@ -1856,6 +1855,7 @@
 
 :- import_module char.
 :- import_module int.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 
diff --git a/compiler/mlds_to_c.m b/compiler/mlds_to_c.m
index af14c85d4..1eb0e9e91 100644
--- a/compiler/mlds_to_c.m
+++ b/compiler/mlds_to_c.m
@@ -78,7 +78,6 @@
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.         % for pred_proc_id.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -107,6 +106,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/mlds_to_cs.m b/compiler/mlds_to_cs.m
index 3848de221..b91c03ce9 100644
--- a/compiler/mlds_to_cs.m
+++ b/compiler/mlds_to_cs.m
@@ -50,7 +50,6 @@
 :- import_module backend_libs.c_util.
 :- import_module backend_libs.rtti.
 :- import_module hlds.hlds_pred.           % for pred_proc_id.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -79,6 +78,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/mlds_to_gcc.m b/compiler/mlds_to_gcc.m
index 7483f1289..966620169 100644
--- a/compiler/mlds_to_gcc.m
+++ b/compiler/mlds_to_gcc.m
@@ -159,7 +159,6 @@
 :- import_module backend_libs.rtti. % for rtti.addr_to_string.
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_pred.    % for proc_id_to_int and invalid_pred_id
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -180,6 +179,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/mlds_to_il.m b/compiler/mlds_to_il.m
index 023058ec3..643430d2a 100644
--- a/compiler/mlds_to_il.m
+++ b/compiler/mlds_to_il.m
@@ -149,7 +149,6 @@
 :- import_module backend_libs.foreign.
 :- import_module backend_libs.rtti.
 :- import_module hlds.code_model.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
 :- import_module ml_backend.ml_code_util.
@@ -169,6 +168,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 
diff --git a/compiler/mlds_to_ilasm.m b/compiler/mlds_to_ilasm.m
index dadb14a87..eabb5f667 100644
--- a/compiler/mlds_to_ilasm.m
+++ b/compiler/mlds_to_ilasm.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1999-2009 The University of Melbourne.
+% Copyright (C) 1999-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -34,8 +34,6 @@
 
 :- implementation.
 
-% :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.options.
 :- import_module ml_backend.ilasm.
@@ -48,6 +46,7 @@
 :- import_module bool.
 :- import_module list.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/mlds_to_java.m b/compiler/mlds_to_java.m
index 6bd91860b..c6f7a050f 100644
--- a/compiler/mlds_to_java.m
+++ b/compiler/mlds_to_java.m
@@ -89,7 +89,6 @@
 :- import_module backend_libs.rtti.
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_pred.           % for pred_proc_id.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -122,6 +121,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/mlds_to_managed.m b/compiler/mlds_to_managed.m
index 0e6256403..f9cd1ab44 100644
--- a/compiler/mlds_to_managed.m
+++ b/compiler/mlds_to_managed.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002-2007, 2009 The University of Melbourne.
+% Copyright (C) 2002-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -41,7 +41,6 @@
 :- implementation.
 
 :- import_module backend_libs.c_util.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
 :- import_module ml_backend.ilds.
@@ -59,6 +58,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/mmc_analysis.m b/compiler/mmc_analysis.m
index 4b2ccaf96..171058565 100644
--- a/compiler/mmc_analysis.m
+++ b/compiler/mmc_analysis.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2003-2006, 2008-2009 The University of Melbourne.
+% Copyright (C) 2003-2006, 2008-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -44,7 +44,6 @@
 :- implementation.
 
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -64,6 +63,7 @@
 :- import_module bool.
 :- import_module list.
 :- import_module maybe.
+:- import_module require.
 :- import_module string.
 :- import_module io.
 :- import_module unit.
diff --git a/compiler/mode_constraints.m b/compiler/mode_constraints.m
index c0afb3a7c..af09d15a6 100644
--- a/compiler/mode_constraints.m
+++ b/compiler/mode_constraints.m
@@ -62,7 +62,6 @@
 :- import_module hlds.passes_aux.
 :- import_module hlds.quantification.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.
@@ -87,6 +86,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module robdd.
 :- import_module set.
 :- import_module solutions.
diff --git a/compiler/mode_errors.m b/compiler/mode_errors.m
index df2fb3d47..e724673ce 100644
--- a/compiler/mode_errors.m
+++ b/compiler/mode_errors.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2009 The University of Melbourne.
+% Copyright (C) 1994-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -247,7 +247,6 @@
 :- import_module hlds.hlds_out.hlds_out_mode.
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.mercury_to_mercury.
@@ -261,6 +260,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/mode_info.m b/compiler/mode_info.m
index 2c409e76b..c1c9c7b88 100644
--- a/compiler/mode_info.m
+++ b/compiler/mode_info.m
@@ -336,13 +336,13 @@
 :- import_module check_hlds.mode_errors.
 :- import_module hlds.hlds_clauses.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svbag.
 :- import_module term.
diff --git a/compiler/mode_ordering.m b/compiler/mode_ordering.m
index 51db34b01..941eacebc 100644
--- a/compiler/mode_ordering.m
+++ b/compiler/mode_ordering.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001-2009 The University of Melbourne.
+% Copyright (C) 2001-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -51,8 +51,6 @@
 % :- import_module mode_robdd.check.
 % :- import_module mode_robdd.tfeir.
 :- import_module mode_robdd.tfeirn.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.program_representation.
 :- import_module parse_tree.
@@ -62,6 +60,7 @@
 :- import_module cord.
 :- import_module digraph.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module stack.
diff --git a/compiler/mode_util.m b/compiler/mode_util.m
index a25ddaaa8..7d19ec6c8 100644
--- a/compiler/mode_util.m
+++ b/compiler/mode_util.m
@@ -201,8 +201,6 @@
 :- import_module check_hlds.inst_util.
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_data.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_mode.
@@ -212,6 +210,7 @@
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/modecheck_call.m b/compiler/modecheck_call.m
index 28b9be61f..b2f1fee4a 100644
--- a/compiler/modecheck_call.m
+++ b/compiler/modecheck_call.m
@@ -88,14 +88,13 @@
 :- import_module check_hlds.modes.
 :- import_module check_hlds.unify_proc.
 :- import_module hlds.instmap.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_mode.
 :- import_module parse_tree.prog_type.
 
 :- import_module bool.
 :- import_module map.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 
diff --git a/compiler/modecheck_conj.m b/compiler/modecheck_conj.m
index 6963a6719..82ef8f5cc 100644
--- a/compiler/modecheck_conj.m
+++ b/compiler/modecheck_conj.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2009 The University of Melbourne.
+% Copyright (C) 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -41,8 +41,6 @@
 :- import_module hlds.hlds_module.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.instmap.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.
 :- import_module parse_tree.prog_data.
 
@@ -53,6 +51,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/modecheck_goal.m b/compiler/modecheck_goal.m
index 8d0cd17d5..dd0760c3e 100644
--- a/compiler/modecheck_goal.m
+++ b/compiler/modecheck_goal.m
@@ -132,8 +132,6 @@
 :- import_module hlds.hlds_pred.
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.
@@ -149,6 +147,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/modecheck_unify.m b/compiler/modecheck_unify.m
index b05d2f02a..c009abebc 100644
--- a/compiler/modecheck_unify.m
+++ b/compiler/modecheck_unify.m
@@ -62,7 +62,6 @@
 :- import_module hlds.hlds_pred.
 :- import_module hlds.instmap.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.
@@ -79,6 +78,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/modecheck_util.m b/compiler/modecheck_util.m
index 75a17dabc..f7df8c5c9 100644
--- a/compiler/modecheck_util.m
+++ b/compiler/modecheck_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2009 The University of Melbourne.
+% Copyright (C) 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -206,7 +206,6 @@
 :- import_module hlds.quantification.
 :- import_module hlds.special_pred.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -229,6 +228,7 @@
 :- import_module map.
 :- import_module pair.
 :- import_module queue.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/modes.m b/compiler/modes.m
index e6c24c2cb..d8bcbf23b 100644
--- a/compiler/modes.m
+++ b/compiler/modes.m
@@ -152,7 +152,6 @@
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -167,6 +166,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module queue.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/module_cmds.m b/compiler/module_cmds.m
index cc1a9d750..b42fdabfb 100644
--- a/compiler/module_cmds.m
+++ b/compiler/module_cmds.m
@@ -192,7 +192,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.process_util.
 :- import_module libs.handle_options.   % for grade_directory_component
 :- import_module libs.options.
@@ -204,6 +203,7 @@
 :- import_module dir.
 :- import_module getopt_io.
 :- import_module int.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/module_imports.m b/compiler/module_imports.m
index 5170212bc..109e176e5 100644
--- a/compiler/module_imports.m
+++ b/compiler/module_imports.m
@@ -251,12 +251,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module parse_tree.modules.    % undesirable dependency
 
 :- import_module bool.
 :- import_module dir.
+:- import_module require.
 :- import_module set.
 :- import_module svset.
 :- import_module term.
diff --git a/compiler/module_qual.m b/compiler/module_qual.m
index c7dd50b59..6d05950f8 100644
--- a/compiler/module_qual.m
+++ b/compiler/module_qual.m
@@ -128,7 +128,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module parse_tree.module_imports.
 :- import_module parse_tree.prog_io_sym_name.
@@ -138,6 +137,7 @@
 :- import_module assoc_list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module svmap.
diff --git a/compiler/modules.m b/compiler/modules.m
index fb6699090..d58959075 100644
--- a/compiler/modules.m
+++ b/compiler/modules.m
@@ -367,7 +367,6 @@
 :- implementation.
 
 :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module libs.handle_options.
 :- import_module libs.options.
 :- import_module make.              % XXX undesirable dependency
@@ -395,6 +394,7 @@
 :- import_module map.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module sparse_bitset.
diff --git a/compiler/opt_util.m b/compiler/opt_util.m
index f990b0f08..88b810234 100644
--- a/compiler/opt_util.m
+++ b/compiler/opt_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2009 The University of Melbourne.
+% Copyright (C) 1994-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -323,12 +323,12 @@
 :- import_module backend_libs.builtin_ops.
 :- import_module check_hlds.type_util.
 :- import_module hlds.special_pred.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.exprn_aux.
 :- import_module parse_tree.prog_data.
 
 :- import_module int.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/optimize.m b/compiler/optimize.m
index 36e40e62c..5dcc01e1b 100644
--- a/compiler/optimize.m
+++ b/compiler/optimize.m
@@ -37,7 +37,6 @@
 
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.options.
 :- import_module ll_backend.continuation_info.
@@ -63,6 +62,7 @@
 :- import_module io.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/options.m b/compiler/options.m
index 92c3a6a4c..07876239c 100644
--- a/compiler/options.m
+++ b/compiler/options.m
@@ -985,7 +985,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.handle_options.
 
 :- import_module assoc_list.
@@ -996,6 +995,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 
diff --git a/compiler/options_file.m b/compiler/options_file.m
index aa84d8759..bce831114 100644
--- a/compiler/options_file.m
+++ b/compiler/options_file.m
@@ -78,7 +78,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.error_util.
@@ -90,6 +89,7 @@
 :- import_module dir.
 :- import_module exception.
 :- import_module map.
+:- import_module require.
 :- import_module std_util.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/ordering_mode_constraints.m b/compiler/ordering_mode_constraints.m
index b7091bc85..33c3b4fbe 100644
--- a/compiler/ordering_mode_constraints.m
+++ b/compiler/ordering_mode_constraints.m
@@ -107,7 +107,6 @@
 :- import_module hlds.hlds_error_util.
 :- import_module hlds.hlds_goal.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module mdbcomp.
 :- import_module mdbcomp.program_representation.
@@ -123,6 +122,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svset.
 
diff --git a/compiler/par_conj_gen.m b/compiler/par_conj_gen.m
index f6e061a6d..fde833a15 100644
--- a/compiler/par_conj_gen.m
+++ b/compiler/par_conj_gen.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1998-2000,2002-2009 University of Melbourne.
+% Copyright (C) 1998-2000,2002-2010 University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -109,7 +109,6 @@
 :- import_module hlds.hlds_llds.
 :- import_module hlds.hlds_module.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.code_gen.
@@ -124,6 +123,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module unit.
 
diff --git a/compiler/parallel_to_plain_conj.m b/compiler/parallel_to_plain_conj.m
index 7c7ee50bb..0fd157e33 100644
--- a/compiler/parallel_to_plain_conj.m
+++ b/compiler/parallel_to_plain_conj.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=8 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2008 The University of Melbourne.
+% Copyright (C) 2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -33,10 +33,10 @@
 :- implementation.
 
 :- import_module hlds.hlds_goal.
-:- import_module libs.compiler_util.
 
 :- import_module bool.
 :- import_module list.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/passes_aux.m b/compiler/passes_aux.m
index 2a9316d0f..fd44db7bf 100644
--- a/compiler/passes_aux.m
+++ b/compiler/passes_aux.m
@@ -207,7 +207,6 @@
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_module.
 :- import_module hlds.hlds_out.hlds_out_util.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -223,6 +222,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set_tree234.
 :- import_module string.
 :- import_module varset.
diff --git a/compiler/pd_cost.m b/compiler/pd_cost.m
index eb21e4bd9..075361e63 100644
--- a/compiler/pd_cost.m
+++ b/compiler/pd_cost.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1998-2008 University of Melbourne.
+% Copyright (C) 1998-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -42,12 +42,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 
 :- import_module int.
 :- import_module list.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/pd_info.m b/compiler/pd_info.m
index 064693196..da4ed019c 100644
--- a/compiler/pd_info.m
+++ b/compiler/pd_info.m
@@ -119,7 +119,6 @@
 :- import_module check_hlds.inst_match.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_util.
@@ -129,6 +128,7 @@
 :- import_module bool.
 :- import_module int.
 :- import_module io.
+:- import_module require.
 :- import_module term.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/pd_term.m b/compiler/pd_term.m
index a7f01d8d2..6bc2a0098 100644
--- a/compiler/pd_term.m
+++ b/compiler/pd_term.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1998-2001, 2003-2008 The University of Melbourne.
+% Copyright (C) 1998-2001, 2003-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -103,7 +103,6 @@
 :- implementation.
 
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 :- import_module transform_hlds.pd_util.
 
@@ -111,6 +110,7 @@
 :- import_module bool.
 :- import_module int.
 :- import_module map.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/pd_util.m b/compiler/pd_util.m
index 8c84f196f..4e05311a1 100644
--- a/compiler/pd_util.m
+++ b/compiler/pd_util.m
@@ -164,7 +164,6 @@
 :- import_module hlds.goal_util.
 :- import_module hlds.instmap.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.error_util.
@@ -176,6 +175,7 @@
 :- import_module int.
 :- import_module io.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 :- import_module svmap.
diff --git a/compiler/pickle.m b/compiler/pickle.m
index 13d14bb8b..3bf92ecd9 100644
--- a/compiler/pickle.m
+++ b/compiler/pickle.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2008 The University of Melbourne.
+% Copyright (C) 2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -94,8 +94,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module bitmap.
 :- import_module bool.
 :- import_module char.
@@ -106,6 +104,7 @@
 :- import_module io.
 :- import_module list.
 :- import_module map.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/polyhedron.m b/compiler/polyhedron.m
index 7da4ae997..9e00d76cd 100644
--- a/compiler/polyhedron.m
+++ b/compiler/polyhedron.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2003, 2005-2007, 2009 The University of Melbourne.
+% Copyright (C) 2003, 2005-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -184,10 +184,10 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.rat.
 
 :- import_module pair.
+:- import_module require.
 :- import_module svmap.
 :- import_module svvarset.
 :- import_module varset.
diff --git a/compiler/polymorphism.m b/compiler/polymorphism.m
index 81dc3ca05..beea75945 100644
--- a/compiler/polymorphism.m
+++ b/compiler/polymorphism.m
@@ -400,7 +400,6 @@
 :- import_module hlds.special_pred.
 :- import_module libs.
 :- import_module libs.compiler_util.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -418,6 +417,7 @@
 :- import_module io.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/post_term_analysis.m b/compiler/post_term_analysis.m
index 0c585ccdd..2d4acd3b9 100644
--- a/compiler/post_term_analysis.m
+++ b/compiler/post_term_analysis.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %----------------------------------------------------------------------------%
-% Copyright (C) 2005-2007, 2009 The University of Melbourne.
+% Copyright (C) 2005-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %----------------------------------------------------------------------------%
@@ -42,7 +42,6 @@
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.special_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -55,6 +54,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 
 %----------------------------------------------------------------------------%
diff --git a/compiler/post_typecheck.m b/compiler/post_typecheck.m
index 0865817ae..8ff49e9bb 100644
--- a/compiler/post_typecheck.m
+++ b/compiler/post_typecheck.m
@@ -135,7 +135,6 @@
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.pred_table.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.program_representation.
@@ -151,6 +150,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/pred_table.m b/compiler/pred_table.m
index 949ca1169..f0833d386 100644
--- a/compiler/pred_table.m
+++ b/compiler/pred_table.m
@@ -30,7 +30,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.error_util.
 :- import_module parse_tree.prog_out.
 :- import_module parse_tree.prog_type.
@@ -39,6 +38,7 @@
 :- import_module int.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module svmulti_map.
diff --git a/compiler/proc_gen.m b/compiler/proc_gen.m
index 4f2d52591..8a73bf948 100644
--- a/compiler/proc_gen.m
+++ b/compiler/proc_gen.m
@@ -83,7 +83,6 @@
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -111,6 +110,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/proc_label.m b/compiler/proc_label.m
index 1d8457efa..c11830a32 100644
--- a/compiler/proc_label.m
+++ b/compiler/proc_label.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2003-2008 The University of Melbourne.
+% Copyright (C) 2003-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -47,13 +47,12 @@
 :- implementation.
 
 :- import_module backend_libs.rtti.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type.
 
 :- import_module bool.
 :- import_module list.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 
 make_proc_label_from_rtti(RttiProcLabel) = ProcLabel :-
diff --git a/compiler/prog_ctgc.m b/compiler/prog_ctgc.m
index 161056ac8..ec8355b31 100644
--- a/compiler/prog_ctgc.m
+++ b/compiler/prog_ctgc.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006, 2008-2009 The University of Melbourne.
+% Copyright (C) 2006, 2008-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -171,7 +171,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_io_sym_name.
 :- import_module parse_tree.prog_io_util.
@@ -182,6 +181,7 @@
 
 :- import_module int.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module varset.
diff --git a/compiler/prog_data.m b/compiler/prog_data.m
index cffc50f2a..c1bee59bf 100644
--- a/compiler/prog_data.m
+++ b/compiler/prog_data.m
@@ -43,8 +43,7 @@
 :- implementation.
 
 :- import_module library.
-:- import_module libs.compiler_util.
-
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/prog_event.m b/compiler/prog_event.m
index 7cc114983..a48181f2a 100644
--- a/compiler/prog_event.m
+++ b/compiler/prog_event.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006-2009 The University of Melbourne.
+% Copyright (C) 2006-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -59,7 +59,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.builtin_lib_types.
 :- import_module parse_tree.prog_mode.
@@ -74,6 +73,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svbimap.
diff --git a/compiler/prog_foreign.m b/compiler/prog_foreign.m
index 283dc36d5..ef95b3faf 100644
--- a/compiler/prog_foreign.m
+++ b/compiler/prog_foreign.m
@@ -27,6 +27,7 @@
 :- module parse_tree.prog_foreign.
 :- interface.
 
+:- import_module libs.
 :- import_module libs.globals.
 :- import_module parse_tree.prog_data.
 :- import_module mdbcomp.prim_data.
diff --git a/compiler/prog_io.m b/compiler/prog_io.m
index f092221ed..fcecfae29 100644
--- a/compiler/prog_io.m
+++ b/compiler/prog_io.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------e
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------e
-% Copyright (C) 1993-2009 The University of Melbourne.
+% Copyright (C) 1993-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -184,7 +184,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module parse_tree.file_names.
 :- import_module parse_tree.mercury_to_mercury.
@@ -212,6 +211,7 @@
 :- import_module map.
 :- import_module pair.
 :- import_module parser.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term_io.
diff --git a/compiler/prog_io_pragma.m b/compiler/prog_io_pragma.m
index 408388c75..0986caefb 100644
--- a/compiler/prog_io_pragma.m
+++ b/compiler/prog_io_pragma.m
@@ -43,7 +43,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.rat.
 :- import_module parse_tree.error_util.
 :- import_module parse_tree.mercury_to_mercury.
@@ -59,6 +58,7 @@
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module unit.
diff --git a/compiler/prog_io_type_defn.m b/compiler/prog_io_type_defn.m
index 88c43f9ee..9fca40227 100644
--- a/compiler/prog_io_type_defn.m
+++ b/compiler/prog_io_type_defn.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------e
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------e
-% Copyright (C) 2008-2009 The University of Melbourne.
+% Copyright (C) 2008-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -53,7 +53,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module parse_tree.error_util.
 :- import_module parse_tree.mercury_to_mercury.
@@ -65,6 +64,7 @@
 
 :- import_module bool.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module unit.
diff --git a/compiler/prog_io_typeclass.m b/compiler/prog_io_typeclass.m
index 8c1b1a52d..4fa4dfffb 100644
--- a/compiler/prog_io_typeclass.m
+++ b/compiler/prog_io_typeclass.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2009 University of Melbourne.
+% Copyright (C) 1997-2010 University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -58,7 +58,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.error_util.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_io.
@@ -72,6 +71,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module solutions.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/prog_io_util.m b/compiler/prog_io_util.m
index 361af21d3..a98626ec6 100644
--- a/compiler/prog_io_util.m
+++ b/compiler/prog_io_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1996-2009 The University of Melbourne.
+% Copyright (C) 1996-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -232,12 +232,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_io_sym_name.
 :- import_module parse_tree.prog_out.
 :- import_module parse_tree.prog_util.
 
+:- import_module require.
 :- import_module set.
 :- import_module term.
 
diff --git a/compiler/prog_mode.m b/compiler/prog_mode.m
index fd99db704..60d90f764 100644
--- a/compiler/prog_mode.m
+++ b/compiler/prog_mode.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2004-2006, 2008-2009 The University of Melbourne.
+% Copyright (C) 2004-2006, 2008-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -133,10 +133,10 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 
 :- import_module map.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/prog_out.m b/compiler/prog_out.m
index 47b654247..570d06663 100644
--- a/compiler/prog_out.m
+++ b/compiler/prog_out.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1993-2009 The University of Melbourne.
+% Copyright (C) 1993-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -152,12 +152,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.error_util.
 :- import_module parse_tree.prog_util.
 
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 :- import_module term_io.
diff --git a/compiler/prog_rep.m b/compiler/prog_rep.m
index e76fc112a..976d09fe6 100644
--- a/compiler/prog_rep.m
+++ b/compiler/prog_rep.m
@@ -85,13 +85,13 @@
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_util.
 
 :- import_module int.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module std_util.
 :- import_module string.
diff --git a/compiler/prog_type.m b/compiler/prog_type.m
index 03941ea35..f80678f2e 100644
--- a/compiler/prog_type.m
+++ b/compiler/prog_type.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2009 The University of Melbourne.
+% Copyright (C) 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -405,11 +405,11 @@
 :- implementation.
 
 :- import_module libs.options.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_out.
 :- import_module parse_tree.prog_util.
 :- import_module parse_tree.prog_type_subst.
 
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 
diff --git a/compiler/prog_type_subst.m b/compiler/prog_type_subst.m
index 0adf554f5..0441cfff7 100644
--- a/compiler/prog_type_subst.m
+++ b/compiler/prog_type_subst.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2006, 2009 The University of Melbourne.
+% Copyright (C) 2005-2006, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -121,10 +121,9 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/prog_util.m b/compiler/prog_util.m
index 3819da7ea..2b4aa863e 100644
--- a/compiler/prog_util.m
+++ b/compiler/prog_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2001, 2003-2009 The University of Melbourne.
+% Copyright (C) 1994-2001, 2003-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -189,7 +189,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_out.
 
@@ -197,6 +196,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module term_io.
diff --git a/compiler/prop_mode_constraints.m b/compiler/prop_mode_constraints.m
index e70ca3c7c..b13b836ff 100644
--- a/compiler/prop_mode_constraints.m
+++ b/compiler/prop_mode_constraints.m
@@ -83,14 +83,13 @@
 :- import_module hlds.hlds_clauses.
 :- import_module hlds.hlds_error_util.
 :- import_module hlds.hlds_goal.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.
 :- import_module parse_tree.error_util.
 :- import_module parse_tree.prog_data.
 
 :- import_module bool.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/pseudo_type_info.m b/compiler/pseudo_type_info.m
index 8c836753b..eed76730b 100644
--- a/compiler/pseudo_type_info.m
+++ b/compiler/pseudo_type_info.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1996-2000,2002-2003, 2005-2009 The University of Melbourne.
+% Copyright (C) 1996-2000,2002-2003, 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -63,14 +63,13 @@
 
 :- implementation.
 
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_type.
 
 :- import_module int.
 :- import_module list.
+:- import_module require.
 :- import_module term.
 
 %---------------------------------------------------------------------------%
diff --git a/compiler/purity.m b/compiler/purity.m
index 06a51fe13..55b3e6ba1 100644
--- a/compiler/purity.m
+++ b/compiler/purity.m
@@ -177,7 +177,6 @@
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -190,17 +189,18 @@
 :- import_module parse_tree.prog_out.
 :- import_module parse_tree.prog_type.
 
+:- import_module assoc_list.
 :- import_module bool.
 :- import_module int.
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
 :- import_module varset.
-:- import_module assoc_list.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/quantification.m b/compiler/quantification.m
index 82c5e0a55..4fba06455 100644
--- a/compiler/quantification.m
+++ b/compiler/quantification.m
@@ -105,13 +105,13 @@
 
 :- import_module hlds.goal_util.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 
 :- import_module assoc_list.
 :- import_module bool.
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module tree_bitset.
 :- import_module term.
@@ -2235,7 +2235,7 @@ goal_expr_vars_no_lambda_2(NonLocalsToRecompute, GoalExpr, !Set) :-
 
 unify_rhs_vars_maybe_lambda(NonLocalsToRecompute, RHS, !Set, !LambdaSet) :-
     (
-        RHS = rhs_var(Y), 
+        RHS = rhs_var(Y),
         insert(!.Set, Y, !:Set)
     ;
         RHS = rhs_functor(_, _, ArgVars),
@@ -2256,7 +2256,7 @@ unify_rhs_vars_maybe_lambda(NonLocalsToRecompute, RHS, !Set, !LambdaSet) :-
 
 unify_rhs_vars_maybe_lambda_and_bi_impl(RHS, !Set, !LambdaSet) :-
     (
-        RHS = rhs_var(Y), 
+        RHS = rhs_var(Y),
         insert(!.Set, Y, !:Set)
     ;
         RHS = rhs_functor(_, _, ArgVars),
@@ -2279,7 +2279,7 @@ unify_rhs_vars_maybe_lambda_and_bi_impl(RHS, !Set, !LambdaSet) :-
 
 unify_rhs_vars_no_lambda(NonLocalsToRecompute, RHS, MaybeSetArgs, !Set) :-
     (
-        RHS = rhs_var(Y), 
+        RHS = rhs_var(Y),
         insert(!.Set, Y, !:Set)
     ;
         RHS = rhs_functor(_, _, ArgVars),
diff --git a/compiler/rat.m b/compiler/rat.m
index eaa96ae4d..d32d9b074 100644
--- a/compiler/rat.m
+++ b/compiler/rat.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-1998, 2003, 2005-2006 The University of Melbourne.
+% Copyright (C) 1997-1998, 2003, 2005-2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU Library General
 % Public License - see the file COPYING.LIB in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -79,9 +79,8 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module int.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
@@ -245,4 +244,3 @@ this_file = "rat.m".
 %-----------------------------------------------------------------------------%
 :- end_module rat.
 %-----------------------------------------------------------------------------%
-%-----------------------------------------------------------------------------%
diff --git a/compiler/rbmm.add_rbmm_goal_infos.m b/compiler/rbmm.add_rbmm_goal_infos.m
index 4f92da644..08192c0c4 100644
--- a/compiler/rbmm.add_rbmm_goal_infos.m
+++ b/compiler/rbmm.add_rbmm_goal_infos.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007-2009 The University of Melbourne.
+% Copyright (C) 2007-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -62,7 +62,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.
@@ -78,6 +77,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/rbmm.condition_renaming.m b/compiler/rbmm.condition_renaming.m
index 56a82f931..52b24bbf4 100644
--- a/compiler/rbmm.condition_renaming.m
+++ b/compiler/rbmm.condition_renaming.m
@@ -132,8 +132,6 @@
 :- import_module check_hlds.
 :- import_module check_hlds.goal_path.
 :- import_module hlds.hlds_goal.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module transform_hlds.rbmm.points_to_graph.
 :- import_module transform_hlds.smm_common.
 
@@ -141,6 +139,7 @@
 :- import_module int.
 :- import_module list.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module svset.
diff --git a/compiler/rbmm.execution_path.m b/compiler/rbmm.execution_path.m
index 4f2c21e3b..d04c20977 100644
--- a/compiler/rbmm.execution_path.m
+++ b/compiler/rbmm.execution_path.m
@@ -35,13 +35,12 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.
 :- import_module parse_tree.prog_data.
 :- import_module transform_hlds.smm_common.
 
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module list.
diff --git a/compiler/rbmm.interproc_region_lifetime.m b/compiler/rbmm.interproc_region_lifetime.m
index 589212b26..7bef427ad 100644
--- a/compiler/rbmm.interproc_region_lifetime.m
+++ b/compiler/rbmm.interproc_region_lifetime.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2007, 2009 The University of Melbourne.
+% Copyright (C) 2005-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -64,8 +64,6 @@
 :- import_module hlds.arg_info.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_data.
@@ -80,6 +78,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/rbmm.live_region_analysis.m b/compiler/rbmm.live_region_analysis.m
index dd63e855d..370a12296 100644
--- a/compiler/rbmm.live_region_analysis.m
+++ b/compiler/rbmm.live_region_analysis.m
@@ -45,8 +45,6 @@
 :- import_module hlds.arg_info.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_data.
@@ -58,6 +56,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/rbmm.live_variable_analysis.m b/compiler/rbmm.live_variable_analysis.m
index f32fb94d7..564ce88bf 100644
--- a/compiler/rbmm.live_variable_analysis.m
+++ b/compiler/rbmm.live_variable_analysis.m
@@ -37,8 +37,6 @@
 :- import_module hlds.arg_info.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_data.
@@ -49,6 +47,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/rbmm.points_to_analysis.m b/compiler/rbmm.points_to_analysis.m
index 1d31ff9bb..2fb1620d2 100644
--- a/compiler/rbmm.points_to_analysis.m
+++ b/compiler/rbmm.points_to_analysis.m
@@ -52,8 +52,6 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.
 :- import_module parse_tree.prog_data.
 :- import_module transform_hlds.dependency_graph.
@@ -67,6 +65,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/rbmm.points_to_graph.m b/compiler/rbmm.points_to_graph.m
index 80b56461b..8df526dab 100644
--- a/compiler/rbmm.points_to_graph.m
+++ b/compiler/rbmm.points_to_graph.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2007, 2009 The University of Melbourne.
+% Copyright (C) 2005-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU Library General
 % Public License - see the file COPYING.LIB in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -269,13 +269,12 @@
 
 :- implementation.
 
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module transform_hlds.smm_common.
 
 :- import_module assoc_list.
 :- import_module counter.
 :- import_module pair.
+:- import_module require.
 :- import_module solutions.
 :- import_module svmap.
 :- import_module svset.
diff --git a/compiler/rbmm.region_arguments.m b/compiler/rbmm.region_arguments.m
index b71e971f9..fd25319f2 100644
--- a/compiler/rbmm.region_arguments.m
+++ b/compiler/rbmm.region_arguments.m
@@ -73,11 +73,11 @@
 :- import_module check_hlds.goal_path.
 :- import_module hlds.hlds_goal.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 
 :- import_module bool.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/rbmm.region_instruction.m b/compiler/rbmm.region_instruction.m
index 86e5d4205..bedd3977e 100644
--- a/compiler/rbmm.region_instruction.m
+++ b/compiler/rbmm.region_instruction.m
@@ -113,12 +113,11 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_llds.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module transform_hlds.rbmm.points_to_graph.
 
 :- import_module bool.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module svset.
diff --git a/compiler/rbmm.region_resurrection_renaming.m b/compiler/rbmm.region_resurrection_renaming.m
index cfa8bf9c6..bf2a675ea 100644
--- a/compiler/rbmm.region_resurrection_renaming.m
+++ b/compiler/rbmm.region_resurrection_renaming.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007, 2009 The University of Melbourne.
+% Copyright (C) 2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -152,8 +152,6 @@
 :- implementation.
 
 :- import_module hlds.hlds_goal.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module transform_hlds.rbmm.points_to_graph.
 
 :- import_module assoc_list.
@@ -161,6 +159,7 @@
 :- import_module counter.
 :- import_module int.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module svset.
diff --git a/compiler/rbmm.region_transformation.m b/compiler/rbmm.region_transformation.m
index aac629f9a..0832fa7e7 100644
--- a/compiler/rbmm.region_transformation.m
+++ b/compiler/rbmm.region_transformation.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007-2009 The University of Melbourne.
+% Copyright (C) 2007-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -83,8 +83,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.builtin_lib_types.
 :- import_module parse_tree.prog_mode.
@@ -96,6 +94,7 @@
 :- import_module int.
 :- import_module list.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module svvarset.
diff --git a/compiler/reassign.m b/compiler/reassign.m
index f765827f5..174d7321d 100644
--- a/compiler/reassign.m
+++ b/compiler/reassign.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002-2009 The University of Melbourne.
+% Copyright (C) 2002-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -111,12 +111,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.code_util.
 
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 
diff --git a/compiler/recompilation.check.m b/compiler/recompilation.check.m
index b688dd69b..aa6d8391b 100644
--- a/compiler/recompilation.check.m
+++ b/compiler/recompilation.check.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002-2009 The University of Melbourne.
+% Copyright (C) 2002-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -66,7 +66,6 @@
 :- import_module hlds.hlds_data.    % for type field_access_type
 :- import_module hlds.hlds_pred.    % for field_access_function_name,
                                     % type pred_id.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module libs.timestamp.
 :- import_module parse_tree.error_util.
@@ -89,6 +88,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module parser.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/recompilation.usage.m b/compiler/recompilation.usage.m
index 9ca770fa1..f787533d3 100644
--- a/compiler/recompilation.usage.m
+++ b/compiler/recompilation.usage.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001-2009 University of Melbourne.
+% Copyright (C) 2001-2010 University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -86,7 +86,6 @@
 :- import_module hlds.hlds_pred.
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -105,6 +104,7 @@
 :- import_module bool.
 :- import_module int.
 :- import_module queue.
+:- import_module require.
 :- import_module solutions.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/recompilation.version.m b/compiler/recompilation.version.m
index 54d7bf3e0..74b41bbd0 100644
--- a/compiler/recompilation.version.m
+++ b/compiler/recompilation.version.m
@@ -48,7 +48,6 @@
 
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_mode.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.error_util.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.prog_io_sym_name.
@@ -59,6 +58,7 @@
 :- import_module bool.
 :- import_module list.
 :- import_module map.
+:- import_module require.
 :- import_module string.
 :- import_module varset.
 
diff --git a/compiler/rtti.m b/compiler/rtti.m
index 9a1a2bdbf..a631a921b 100644
--- a/compiler/rtti.m
+++ b/compiler/rtti.m
@@ -30,6 +30,7 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.hlds_rtti.
+:- import_module libs.
 :- import_module libs.globals.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
@@ -958,13 +959,12 @@
 :- import_module check_hlds.        % needed for type_util, mode_util
 :- import_module check_hlds.mode_util.
 :- import_module hlds.hlds_data.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_foreign.
 :- import_module parse_tree.prog_type.
 
 :- import_module int.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module table_builtin.
 :- import_module varset.
diff --git a/compiler/rtti_out.m b/compiler/rtti_out.m
index c793c3ece..a3f2db3a2 100644
--- a/compiler/rtti_out.m
+++ b/compiler/rtti_out.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2000-2007, 2009 The University of Melbourne.
+% Copyright (C) 2000-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -107,7 +107,6 @@
 :- import_module backend_libs.type_ctor_info.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_rtti.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module ll_backend.code_util.
 :- import_module ll_backend.layout_out.
@@ -125,6 +124,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmulti_map.
 :- import_module univ.
diff --git a/compiler/rtti_to_mlds.m b/compiler/rtti_to_mlds.m
index 406c48d56..8631776f0 100644
--- a/compiler/rtti_to_mlds.m
+++ b/compiler/rtti_to_mlds.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001-2009 The University of Melbourne.
+% Copyright (C) 2001-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -54,7 +54,6 @@
 :- import_module backend_libs.type_ctor_info.
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_rtti.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module mdbcomp.prim_data.
 :- import_module ml_backend.ml_closure_gen.
@@ -73,6 +72,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module term.
diff --git a/compiler/saved_vars.m b/compiler/saved_vars.m
index 56162186d..7779bda90 100644
--- a/compiler/saved_vars.m
+++ b/compiler/saved_vars.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1996-2009 The University of Melbourne.
+% Copyright (C) 1996-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -50,7 +50,6 @@
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.passes_aux.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 
 :- import_module bool.
@@ -58,6 +57,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/simplify.m b/compiler/simplify.m
index 72995327b..e62051885 100644
--- a/compiler/simplify.m
+++ b/compiler/simplify.m
@@ -139,7 +139,6 @@
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
 :- import_module hlds.special_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.options.
 :- import_module libs.trace_params.
@@ -161,6 +160,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svvarset.
diff --git a/compiler/size_prof.m b/compiler/size_prof.m
index e51752d85..547cb8955 100644
--- a/compiler/size_prof.m
+++ b/compiler/size_prof.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2003-2009 The University of Melbourne.
+% Copyright (C) 2003-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -119,7 +119,6 @@
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -136,6 +135,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/special_pred.m b/compiler/special_pred.m
index dbb7b0c9c..89d4432d2 100644
--- a/compiler/special_pred.m
+++ b/compiler/special_pred.m
@@ -111,7 +111,6 @@
 :- implementation.
 
 :- import_module check_hlds.type_util.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.builtin_lib_types.
@@ -120,6 +119,7 @@
 
 :- import_module bool.
 :- import_module maybe.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/ssdebug.m b/compiler/ssdebug.m
index fecfaedc0..a016a73b6 100755
--- a/compiler/ssdebug.m
+++ b/compiler/ssdebug.m
@@ -201,7 +201,6 @@
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.builtin_lib_types.
 :- import_module parse_tree.file_names.
@@ -213,6 +212,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module svvarset.
diff --git a/compiler/stack_layout.m b/compiler/stack_layout.m
index e4cc829ab..6339840ba 100644
--- a/compiler/stack_layout.m
+++ b/compiler/stack_layout.m
@@ -107,7 +107,6 @@
 :- import_module hlds.hlds_pred.
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module libs.trace_params.
@@ -123,6 +122,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/stack_opt.m b/compiler/stack_opt.m
index b5776fea8..d2d2da991 100644
--- a/compiler/stack_opt.m
+++ b/compiler/stack_opt.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002-2009 The University of Melbourne.
+% Copyright (C) 2002-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -97,7 +97,6 @@
 :- import_module hlds.hlds_out.hlds_out_goal.
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.live_vars.
@@ -116,6 +115,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module svset.
diff --git a/compiler/state_var.m b/compiler/state_var.m
index 7d4b1bae7..d1fe45cd4 100644
--- a/compiler/state_var.m
+++ b/compiler/state_var.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2009 The University of Melbourne.
+% Copyright (C) 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -348,13 +348,13 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_util.
 
 :- import_module char.
 :- import_module int.
 :- import_module io.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module term.
diff --git a/compiler/stdlabel.m b/compiler/stdlabel.m
index 67b0de08a..ab6a9d570 100644
--- a/compiler/stdlabel.m
+++ b/compiler/stdlabel.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006-2007 The University of Melbourne.
+% Copyright (C) 2006-2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -40,13 +40,13 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.opt_util.
 :- import_module mdbcomp.prim_data.
 
 :- import_module bool.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/stm_expand.m b/compiler/stm_expand.m
index e6ca845ca..f947fbe3d 100644
--- a/compiler/stm_expand.m
+++ b/compiler/stm_expand.m
@@ -184,7 +184,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.builtin_lib_types.
 :- import_module parse_tree.prog_data.
@@ -199,6 +198,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/store_alloc.m b/compiler/store_alloc.m
index 36124d139..ab983305a 100644
--- a/compiler/store_alloc.m
+++ b/compiler/store_alloc.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2008 The University of Melbourne.
+% Copyright (C) 1994-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -49,7 +49,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_llds.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.trace_params.
 :- import_module ll_backend.code_util.
@@ -66,6 +65,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/stratify.m b/compiler/stratify.m
index d2ab788bb..3681f5bd6 100644
--- a/compiler/stratify.m
+++ b/compiler/stratify.m
@@ -58,7 +58,6 @@
 :- import_module hlds.hlds_module.
 :- import_module hlds.hlds_pred.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.
@@ -73,6 +72,7 @@
 :- import_module digraph.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/string_switch.m b/compiler/string_switch.m
index 381a194ca..f12ca4b97 100644
--- a/compiler/string_switch.m
+++ b/compiler/string_switch.m
@@ -75,7 +75,6 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_llds.
-:- import_module libs.compiler_util.
 :- import_module ll_backend.code_gen.
 :- import_module ll_backend.lookup_util.
 :- import_module ll_backend.switch_case.
@@ -88,6 +87,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module std_util.
 :- import_module string.
diff --git a/compiler/structure_reuse.analysis.m b/compiler/structure_reuse.analysis.m
index cd85aeb34..b58a10de4 100644
--- a/compiler/structure_reuse.analysis.m
+++ b/compiler/structure_reuse.analysis.m
@@ -102,7 +102,6 @@
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -129,6 +128,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/structure_reuse.direct.choose_reuse.m b/compiler/structure_reuse.direct.choose_reuse.m
index ee1b46558..4780ccd10 100644
--- a/compiler/structure_reuse.direct.choose_reuse.m
+++ b/compiler/structure_reuse.direct.choose_reuse.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006-2009 The University of Melbourne.
+% Copyright (C) 2006-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -112,7 +112,6 @@
 
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_data.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 
 :- import_module float.
@@ -120,6 +119,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmulti_map.
diff --git a/compiler/structure_reuse.direct.detect_garbage.m b/compiler/structure_reuse.direct.detect_garbage.m
index d3897c983..8241159e3 100644
--- a/compiler/structure_reuse.direct.detect_garbage.m
+++ b/compiler/structure_reuse.direct.detect_garbage.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006-2009 The University of Melbourne.
+% Copyright (C) 2006-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -37,7 +37,6 @@
 :- implementation.
 
 :- import_module check_hlds.type_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_out.
 :- import_module transform_hlds.ctgc.datastruct.
@@ -46,6 +45,7 @@
 :- import_module bool.
 :- import_module io.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/structure_reuse.domain.m b/compiler/structure_reuse.domain.m
index 14def9148..510e1911c 100644
--- a/compiler/structure_reuse.domain.m
+++ b/compiler/structure_reuse.domain.m
@@ -271,13 +271,13 @@
 
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_ctgc.
 :- import_module transform_hlds.ctgc.datastruct.
 :- import_module transform_hlds.ctgc.util.
 
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/structure_reuse.indirect.m b/compiler/structure_reuse.indirect.m
index 93102e2ee..f5c526aad 100644
--- a/compiler/structure_reuse.indirect.m
+++ b/compiler/structure_reuse.indirect.m
@@ -1,7 +1,7 @@
 %------------------------------------------------------------------------------%
 % vim: ft=mercury ff=unix ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006-2009 The University of Melbourne.
+% Copyright (C) 2006-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -73,7 +73,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.mercury_to_mercury.
@@ -93,6 +92,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module solutions.
 :- import_module string.
 
diff --git a/compiler/structure_reuse.lbu.m b/compiler/structure_reuse.lbu.m
index 6a6e2fc38..008ef67c1 100644
--- a/compiler/structure_reuse.lbu.m
+++ b/compiler/structure_reuse.lbu.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006-2008 The University of Melbourne.
+% Copyright (C) 2006-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -41,12 +41,12 @@
 
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_llds.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_type.
 
 :- import_module list.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/structure_reuse.lfu.m b/compiler/structure_reuse.lfu.m
index 98a515654..b1d01ed7c 100644
--- a/compiler/structure_reuse.lfu.m
+++ b/compiler/structure_reuse.lfu.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2006-2009 The University of Melbourne.
+% Copyright (C) 2006-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -45,12 +45,12 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_llds.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type.
 
 :- import_module list.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/structure_reuse.versions.m b/compiler/structure_reuse.versions.m
index 21014b787..949cd2eef 100644
--- a/compiler/structure_reuse.versions.m
+++ b/compiler/structure_reuse.versions.m
@@ -1,7 +1,7 @@
 %------------------------------------------------------------------------------%
 % vim: ft=mercury ff=unix ts=4 sw=4 et
 %------------------------------------------------------------------------------%
-% Copyright (C) 2006-2009 The University of Melbourne.
+% Copyright (C) 2006-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -65,7 +65,6 @@
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.
@@ -78,6 +77,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/structure_sharing.analysis.m b/compiler/structure_sharing.analysis.m
index aa5a6b155..971a95e31 100644
--- a/compiler/structure_sharing.analysis.m
+++ b/compiler/structure_sharing.analysis.m
@@ -70,7 +70,6 @@
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -95,6 +94,7 @@
 :- import_module list.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/structure_sharing.domain.m b/compiler/structure_sharing.domain.m
index 0a3080254..864621188 100644
--- a/compiler/structure_sharing.domain.m
+++ b/compiler/structure_sharing.domain.m
@@ -5,18 +5,18 @@
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
-% 
+%
 % File: structure_sharing.domain.m.
 % Main author: nancy.
-% 
+%
 % This module defines the abstract domain for representing structure sharing
 % between data structures.
-% 
+%
 % This domain forms a complete lattice. It has a bottom element (representing
 % the definite absence of any possible structure sharing), and a top element
 % (that represents any possible structure sharing), a least upper bound
 % operation, and a comparison predicate (is_subsumed_by).
-% 
+%
 % The auxiliary functions needed for using the domain within the abstract
 % semantics on which the implementation of the analysis is based are:
 %
@@ -36,7 +36,7 @@
 %
 %   * add: add the sharing created by a primitive operation (unification)
 %     to any existing sharing.
-% 
+%
 % Additional operations:
 %
 %   * extend_datastruct: compute the set of datastructures referring to the
@@ -46,7 +46,7 @@
 %
 %   * conversion operations between the public and private representation
 %     for sharing sets.
-% 
+%
 %-----------------------------------------------------------------------------%
 
 :- module transform_hlds.ctgc.structure_sharing.domain.
@@ -118,7 +118,7 @@
     %
     % Renaming of the formal description of data structure sharing to the
     % actual description of the sharing. The information about the formal
-    % variables needs to be extracted from the module information. 
+    % variables needs to be extracted from the module information.
     % A list of variables and types is used as the actual variables and types.
     % The type variables set in the actual context must also be specified.
     %
@@ -151,8 +151,8 @@
 
     % Add the sharing created by a call to some foreign code. This
     % sharing corresponds to the sharing information with which the
-    % foreign code was manually annotated, or can be predicted to 
-    % "bottom", and in the worst case to "top". 
+    % foreign code was manually annotated, or can be predicted to
+    % "bottom", and in the worst case to "top".
     %
 :- pred add_foreign_proc_sharing(module_info::in, pred_info::in, proc_info::in,
     pred_proc_id::in, pragma_foreign_proc_attributes::in,
@@ -187,7 +187,7 @@
     %
 :- func extend_datastruct(module_info, proc_info, sharing_as, datastruct)
     = list(datastruct).
-:- func extend_datastructs(module_info, proc_info, sharing_as, 
+:- func extend_datastructs(module_info, proc_info, sharing_as,
     list(datastruct)) = list(datastruct).
 
     % apply_widening(ModuleInfo, ProcInfo, WideningLimit, WideningDone,
@@ -259,8 +259,8 @@
     sharing_as::in, sharing_as::out) is det.
 
     % Lookup the sharing information in the sharing table, or if it is not
-    % in there, try to predict it using the information available in the 
-    % module_info. 
+    % in there, try to predict it using the information available in the
+    % module_info.
     %
     % Lookup the sharing information of a procedure identified by its
     % pred_proc_id.
@@ -290,7 +290,7 @@
     list(mer_mode)::in, list(mer_type)::in) is semidet.
 
     % Load all the structure sharing information present in the HLDS into
-    % a sharing table. 
+    % a sharing table.
     %
 :- func load_structure_sharing_table(module_info) = sharing_as_table.
 
@@ -303,7 +303,6 @@
 :- import_module check_hlds.mode_util.
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_llds.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_ctgc.
 :- import_module parse_tree.prog_out.
@@ -317,6 +316,7 @@
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module solutions.
 :- import_module string.
 :- import_module svmap.
@@ -376,7 +376,7 @@ sharing_as_short_description(sharing_as_real_as(SharingSet)) =
 
 sharing_as_project(ListVars, !SharingAs) :-
     sharing_as_project_with_type(inproject, ListVars, !SharingAs).
-sharing_as_project(ListVars, SharingAs) = NewSharingAs :- 
+sharing_as_project(ListVars, SharingAs) = NewSharingAs :-
     sharing_as_project(ListVars, SharingAs, NewSharingAs).
 
 :- pred sharing_as_project_with_type(projection_type::in, prog_vars::in,
@@ -630,9 +630,9 @@ optimization_remove_deaths(ProcInfo, GoalInfo, Sharing0) = Sharing :-
     set.to_sorted_list(Deaths, DeathsList),
     sharing_as_project_with_type(outproject, DeathsList, Sharing0, Sharing).
 
-add_foreign_proc_sharing(ModuleInfo, PredInfo, ProcInfo, ForeignPPId, 
-        Attributes, Args, GoalContext, OldSharing, NewSharing) :- 
-    ForeignSharing = sharing_as_for_foreign_proc(ModuleInfo, 
+add_foreign_proc_sharing(ModuleInfo, PredInfo, ProcInfo, ForeignPPId,
+        Attributes, Args, GoalContext, OldSharing, NewSharing) :-
+    ForeignSharing = sharing_as_for_foreign_proc(ModuleInfo,
         Attributes, ForeignPPId, GoalContext),
 
     ActualVars = list.map(foreign_arg_var, Args),
@@ -645,13 +645,13 @@ add_foreign_proc_sharing(ModuleInfo, PredInfo, ProcInfo, ForeignPPId,
         ActualVars, ActualTypes, CallerTypeVarSet,
         CallerHeadTypeParams, ForeignSharing, ActualSharing),
 
-    NewSharing = sharing_as_comb(ModuleInfo, ProcInfo, ActualSharing, 
+    NewSharing = sharing_as_comb(ModuleInfo, ProcInfo, ActualSharing,
         OldSharing).
 
-:- func sharing_as_for_foreign_proc(module_info, 
+:- func sharing_as_for_foreign_proc(module_info,
     pragma_foreign_proc_attributes, pred_proc_id, prog_context) = sharing_as.
 
-sharing_as_for_foreign_proc(ModuleInfo, Attributes, ForeignPPId, 
+sharing_as_for_foreign_proc(ModuleInfo, Attributes, ForeignPPId,
         ProgContext) = SharingAs :-
     (
         sharing_as_from_user_annotated_sharing(Attributes, SharingAs0)
@@ -662,8 +662,8 @@ sharing_as_for_foreign_proc(ModuleInfo, Attributes, ForeignPPId,
     ->
         SharingAs = sharing_as_bottom
     ;
-        context_to_string(ProgContext, ContextString), 
-        Msg = "foreign proc with unknown sharing (" 
+        context_to_string(ProgContext, ContextString),
+        Msg = "foreign proc with unknown sharing ("
             ++ ContextString ++ ")",
         SharingAs = sharing_as_top_sharing(top_cannot_improve(Msg))
     ).
@@ -671,9 +671,9 @@ sharing_as_for_foreign_proc(ModuleInfo, Attributes, ForeignPPId,
 :- pred sharing_as_from_user_annotated_sharing(
     pragma_foreign_proc_attributes::in, sharing_as::out) is semidet.
 
-sharing_as_from_user_annotated_sharing(Attributes, UserSharingAs) :- 
+sharing_as_from_user_annotated_sharing(Attributes, UserSharingAs) :-
     UserSharing = get_user_annotated_sharing(Attributes),
-    UserSharing = user_sharing(SharingDomain, _MaybeTypes), 
+    UserSharing = user_sharing(SharingDomain, _MaybeTypes),
     % Accept only the value "bottom" and "real" for the structure sharing.
     % If the user has annotated the sharing with unknown sharing, we might
     % try to predict bottom anyway.
@@ -685,11 +685,11 @@ sharing_as_from_user_annotated_sharing(Attributes, UserSharingAs) :-
             SharingDomain = structure_sharing_real(_SharingPairs),
             !:SharingAs = from_structure_sharing_domain(SharingDomain)
 
-            % XXX 
+            % XXX
             % I have the feeling that renaming should not be needed at this
             % place anymore, assuming that every foreign_proc call is
-            % correctly handled at the add_pragma stage? 
-        ), 
+            % correctly handled at the add_pragma stage?
+        ),
         UserSharingAs = !.SharingAs
     ).
 
@@ -773,12 +773,12 @@ extend_datastruct(ModuleInfo, ProcInfo, SharingAs, Datastruct)
         unexpected(this_file, "extend_datastruct with top sharing set.")
     ).
 
-extend_datastructs(ModuleInfo, ProcInfo, SharingAs, Datastructs) 
-        = ExtendedDatastructs :- 
-    DataLists = list.map(extend_datastruct(ModuleInfo, ProcInfo, 
+extend_datastructs(ModuleInfo, ProcInfo, SharingAs, Datastructs)
+        = ExtendedDatastructs :-
+    DataLists = list.map(extend_datastruct(ModuleInfo, ProcInfo,
         SharingAs), Datastructs),
     ExtendedDatastructs = list.foldl(
-        datastruct_lists_least_upper_bound(ModuleInfo, ProcInfo), 
+        datastruct_lists_least_upper_bound(ModuleInfo, ProcInfo),
         DataLists, []).
 
 apply_widening(ModuleInfo, ProcInfo, WideningLimit, WideningDone, !Sharing):-
@@ -843,8 +843,8 @@ sharing_as_table_set(PPId, SharingAs_Status, !Table) :-
 
 %-----------------------------------------------------------------------------%
 
-lookup_sharing_and_comb(ModuleInfo, PredInfo, ProcInfo, SharingTable, 
-        PredId, ProcId, ActualVars, !Sharing):- 
+lookup_sharing_and_comb(ModuleInfo, PredInfo, ProcInfo, SharingTable,
+        PredId, ProcId, ActualVars, !Sharing):-
     PPId = proc(PredId, ProcId),
 
     % XXX do we need to combine the analysis status of sharing information we
@@ -852,16 +852,16 @@ lookup_sharing_and_comb(ModuleInfo, PredInfo, ProcInfo, SharingTable,
     lookup_sharing_or_predict(ModuleInfo, SharingTable, PPId, FormalSharing,
         _Status, _IsPredicted),
 
-    proc_info_get_vartypes(ProcInfo, VarTypes), 
+    proc_info_get_vartypes(ProcInfo, VarTypes),
     map.apply_to_list(ActualVars, VarTypes, ActualTypes),
-       
-    pred_info_get_typevarset(PredInfo, CallerTypeVarSet), 
-    pred_info_get_univ_quant_tvars(PredInfo, CallerHeadTypeParams), 
-    sharing_as_rename_using_module_info(ModuleInfo, PPId, 
+
+    pred_info_get_typevarset(PredInfo, CallerTypeVarSet),
+    pred_info_get_univ_quant_tvars(PredInfo, CallerHeadTypeParams),
+    sharing_as_rename_using_module_info(ModuleInfo, PPId,
         ActualVars, ActualTypes, CallerTypeVarSet, CallerHeadTypeParams,
         FormalSharing, ActualSharing),
 
-    !:Sharing = sharing_as_comb(ModuleInfo, ProcInfo, 
+    !:Sharing = sharing_as_comb(ModuleInfo, ProcInfo,
         ActualSharing, !.Sharing).
 
 lookup_sharing_or_predict(ModuleInfo, SharingTable, PPId, SharingAs, Status,
@@ -932,7 +932,7 @@ top_sharing_not_found(PPId) = TopSharing :-
     ShroudedPredProcId = shroud_pred_proc_id(PPId),
     Reason = top_failed_lookup(ShroudedPredProcId),
     TopSharing = sharing_as_top_sharing(Reason).
-    
+
 %-----------------------------------------------------------------------------%
 
 load_structure_sharing_table(ModuleInfo) = SharingTable :-
@@ -1147,7 +1147,7 @@ sharing_set_project(ProjectionType, Vars, SharingSet0, SharingSet) :-
 :- pred project_and_update_sharing_set(projection_type::in, prog_vars::in,
     prog_var::in, selector_sharing_set::in, sharing_set::in, sharing_set::out)
     is det.
- 
+
 project_and_update_sharing_set(ProjectionType, Vars, Var, SelSet0, !SS) :-
     selector_sharing_set_project(ProjectionType, Vars, SelSet0, SelSet),
     ( selector_sharing_set_is_empty(SelSet) ->
diff --git a/compiler/superhomogeneous.m b/compiler/superhomogeneous.m
index 8ad9e0109..2362b2d70 100644
--- a/compiler/superhomogeneous.m
+++ b/compiler/superhomogeneous.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2009 The University of Melbourne.
+% Copyright (C) 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -118,7 +118,6 @@
 :- import_module hlds.make_hlds.add_clause.
 :- import_module hlds.make_hlds.field_access.
 :- import_module hlds.make_hlds.qual_info.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.  % for get_maybe_from_ground_term_threshold
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.module_qual.
@@ -132,6 +131,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module svvarset.
 :- import_module svset.
diff --git a/compiler/switch_detection.m b/compiler/switch_detection.m
index b3c96be6c..66f6df5d0 100644
--- a/compiler/switch_detection.m
+++ b/compiler/switch_detection.m
@@ -76,7 +76,6 @@
 :- import_module hlds.passes_aux.
 :- import_module hlds.quantification.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.prog_data.
@@ -90,6 +89,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module set_tree234.
 :- import_module string.
diff --git a/compiler/switch_util.m b/compiler/switch_util.m
index 07335e60f..dfecd35cd 100644
--- a/compiler/switch_util.m
+++ b/compiler/switch_util.m
@@ -343,7 +343,6 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_code_util.
 :- import_module hlds.hlds_out.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module parse_tree.prog_type.
 
@@ -351,6 +350,7 @@
 :- import_module cord.
 :- import_module int.
 :- import_module io.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 
diff --git a/compiler/table_gen.m b/compiler/table_gen.m
index ece6d108f..88d2d975f 100644
--- a/compiler/table_gen.m
+++ b/compiler/table_gen.m
@@ -67,7 +67,6 @@
 :- import_module hlds.hlds_rtti.
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.
@@ -85,6 +84,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/tabling_analysis.m b/compiler/tabling_analysis.m
index 36e3283f7..8faf1185c 100644
--- a/compiler/tabling_analysis.m
+++ b/compiler/tabling_analysis.m
@@ -89,7 +89,6 @@
 :- import_module hlds.hlds_error_util.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -106,6 +105,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/tag_switch.m b/compiler/tag_switch.m
index 2393d3fce..c6542a973 100644
--- a/compiler/tag_switch.m
+++ b/compiler/tag_switch.m
@@ -45,7 +45,6 @@
 :- import_module hlds.hlds_llds.
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.code_gen.
@@ -59,6 +58,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 
diff --git a/compiler/term_constr_build.m b/compiler/term_constr_build.m
index 114f14bc7..7bb11f09e 100644
--- a/compiler/term_constr_build.m
+++ b/compiler/term_constr_build.m
@@ -67,7 +67,6 @@
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.lp_rational.
 :- import_module libs.polyhedron.
 :- import_module libs.rat.
@@ -83,6 +82,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module std_util.
 :- import_module string.
diff --git a/compiler/term_constr_data.m b/compiler/term_constr_data.m
index f6a12990c..4f06078b1 100644
--- a/compiler/term_constr_data.m
+++ b/compiler/term_constr_data.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002, 2005-2009 The University of Melbourne.
+% Copyright (C) 2002, 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -384,10 +384,10 @@
 :- import_module hlds.hlds_pred.
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 
 :- import_module int.
+:- import_module require.
 :- import_module std_util.
 :- import_module string.
 :- import_module varset.
diff --git a/compiler/term_constr_errors.m b/compiler/term_constr_errors.m
index dbe92a530..0568f6f53 100644
--- a/compiler/term_constr_errors.m
+++ b/compiler/term_constr_errors.m
@@ -73,7 +73,6 @@
 :- implementation.
 
 :- import_module hlds.hlds_error_util.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.error_util.
@@ -82,6 +81,7 @@
 :- import_module bool.
 :- import_module int.
 :- import_module maybe.
+:- import_module require.
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/term_constr_fixpoint.m b/compiler/term_constr_fixpoint.m
index f4f3a20b0..80be0d758 100644
--- a/compiler/term_constr_fixpoint.m
+++ b/compiler/term_constr_fixpoint.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002, 2005-2009 The University of Melbourne.
+% Copyright (C) 2002, 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -56,7 +56,6 @@
 
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.lp_rational.
 :- import_module libs.options.
@@ -70,6 +69,7 @@
 :- import_module int.
 :- import_module io.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/term_constr_initial.m b/compiler/term_constr_initial.m
index 75c48a52e..ce99838ee 100644
--- a/compiler/term_constr_initial.m
+++ b/compiler/term_constr_initial.m
@@ -57,7 +57,6 @@
 
 :- import_module hlds.hlds_pred.
 :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.lp_rational.
 :- import_module libs.options.
@@ -78,6 +77,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module std_util.
 :- import_module string.
diff --git a/compiler/term_constr_pass2.m b/compiler/term_constr_pass2.m
index e8182728a..76057ccbf 100644
--- a/compiler/term_constr_pass2.m
+++ b/compiler/term_constr_pass2.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2002, 2005-2009 The University of Melbourne.
+% Copyright (C) 2002, 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -53,7 +53,6 @@
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.lp_rational.
 :- import_module libs.polyhedron.
 :- import_module libs.rat.
@@ -69,6 +68,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/term_constr_util.m b/compiler/term_constr_util.m
index 39979ccf4..5897edbaa 100644
--- a/compiler/term_constr_util.m
+++ b/compiler/term_constr_util.m
@@ -193,7 +193,6 @@
 :- import_module hlds.hlds_out.
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module libs.rat.
@@ -201,6 +200,7 @@
 :- import_module transform_hlds.term_norm.
 
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module std_util.
 :- import_module string.
diff --git a/compiler/term_errors.m b/compiler/term_errors.m
index 7cca697f6..4e2a8df67 100644
--- a/compiler/term_errors.m
+++ b/compiler/term_errors.m
@@ -165,7 +165,6 @@
 :- implementation.
 
 :- import_module hlds.hlds_error_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.error_util.
 :- import_module transform_hlds.term_util.
 
@@ -174,6 +173,7 @@
 :- import_module int.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/term_norm.m b/compiler/term_norm.m
index 25e8f0664..3485fe479 100644
--- a/compiler/term_norm.m
+++ b/compiler/term_norm.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2009 The University of Melbourne.
+% Copyright (C) 1997-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -72,13 +72,13 @@
 
 :- import_module check_hlds.type_util.
 :- import_module hlds.hlds_data.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type.
 
 :- import_module bool.
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module svmap.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/term_pass1.m b/compiler/term_pass1.m
index 6886a8bac..9b734e1c2 100644
--- a/compiler/term_pass1.m
+++ b/compiler/term_pass1.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-1998, 2003-2008 The University of Melbourne.
+% Copyright (C) 1997-1998, 2003-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -57,7 +57,6 @@
 
 :- import_module hlds.goal_util.
 :- import_module hlds.hlds_goal.
-:- import_module libs.compiler_util.
 :- import_module libs.lp.
 :- import_module parse_tree.prog_data.
 :- import_module transform_hlds.term_traversal.
@@ -67,6 +66,7 @@
 :- import_module float.
 :- import_module map.
 :- import_module maybe.
+:- import_module require.
 :- import_module set.
 :- import_module svmap.
 :- import_module svset.
@@ -78,15 +78,16 @@
 
 :- type pass1_result
     --->    term_pass1_ok(
+                % One entry for each path through the code.
                 list(term_path_info),
-                        % One entry for each path through the
-                        % code.
+
+                % The next output_supplier map.
                 used_args,
-                        % The next output_supplier map.
+
+                % There is an entry in this list for each procedure in the SCC
+                % in which the set of active vars is not a subset of the
+                % input arguments.
                 list(termination_error_context)
-                        % There is an entry in this list for each procedure in
-                        % the SCC in which the set of active vars is not a
-                        % subset of the input arguments.
             )
     ;       term_pass1_error(
                 list(termination_error_context)
diff --git a/compiler/term_pass2.m b/compiler/term_pass2.m
index 65fcba340..768961ef8 100644
--- a/compiler/term_pass2.m
+++ b/compiler/term_pass2.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-1998, 2003-2008 The University of Melbourne.
+% Copyright (C) 1997-1998, 2003-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -42,7 +42,6 @@
 
 :- import_module check_hlds.mode_util.
 :- import_module hlds.goal_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_data.
 :- import_module transform_hlds.term_errors.
 :- import_module transform_hlds.term_traversal.
@@ -54,6 +53,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module term.
 :- import_module unit.
diff --git a/compiler/term_traversal.m b/compiler/term_traversal.m
index b3cc8ccd7..3079ee465 100644
--- a/compiler/term_traversal.m
+++ b/compiler/term_traversal.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2009 The University of Melbourne.
+% Copyright (C) 1997-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -108,13 +108,13 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type.
 
 :- import_module assoc_list.
 :- import_module bool.
 :- import_module int.
 :- import_module map.
+:- import_module require.
 :- import_module svset.
 
 %-----------------------------------------------------------------------------%
diff --git a/compiler/term_util.m b/compiler/term_util.m
index 595151fce..4bbb91b3c 100644
--- a/compiler/term_util.m
+++ b/compiler/term_util.m
@@ -173,10 +173,10 @@
 
 :- import_module check_hlds.inst_match.
 :- import_module check_hlds.mode_util.
-:- import_module libs.compiler_util.
 :- import_module parse_tree.prog_type.
 
 :- import_module pair.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 %-----------------------------------------------------------------------------%
diff --git a/compiler/termination.m b/compiler/termination.m
index 589e55949..df4dfe2bf 100644
--- a/compiler/termination.m
+++ b/compiler/termination.m
@@ -61,7 +61,6 @@
 :- import_module hlds.hlds_error_util.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.passes_aux.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -81,6 +80,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/trace_gen.m b/compiler/trace_gen.m
index 2555ccd2a..27328f122 100644
--- a/compiler/trace_gen.m
+++ b/compiler/trace_gen.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1997-2009 The University of Melbourne.
+% Copyright (C) 1997-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -249,7 +249,6 @@
 :- import_module hlds.code_model.
 :- import_module hlds.hlds_llds.
 :- import_module hlds.instmap.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module libs.trace_params.
 :- import_module ll_backend.code_util.
@@ -262,6 +261,7 @@
 :- import_module cord.
 :- import_module int.
 :- import_module list.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 :- import_module varset.
diff --git a/compiler/trailing_analysis.m b/compiler/trailing_analysis.m
index aed572100..bdb135003 100644
--- a/compiler/trailing_analysis.m
+++ b/compiler/trailing_analysis.m
@@ -89,7 +89,6 @@
 :- import_module hlds.hlds_error_util.
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -107,6 +106,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/transform_llds.m b/compiler/transform_llds.m
index 9663836e4..6bf33eb7a 100644
--- a/compiler/transform_llds.m
+++ b/compiler/transform_llds.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1998-2001,2003-2007, 2009 The University of Melbourne.
+% Copyright (C) 1998-2001,2003-2007, 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -38,7 +38,6 @@
 :- import_module hlds.hlds_pred.
 :- import_module backend_libs.builtin_ops.
 :- import_module hlds.code_model.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
 
@@ -47,6 +46,7 @@
 :- import_module list.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/try_expand.m b/compiler/try_expand.m
index b8d08c5c5..20d64c370 100644
--- a/compiler/try_expand.m
+++ b/compiler/try_expand.m
@@ -227,8 +227,6 @@
 :- import_module hlds.passes_aux.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.
@@ -241,6 +239,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module term.
diff --git a/compiler/tupling.m b/compiler/tupling.m
index 45433911f..65b504b90 100644
--- a/compiler/tupling.m
+++ b/compiler/tupling.m
@@ -114,11 +114,11 @@
 :- import_module libs.options.
 :- import_module ll_backend.
 :- import_module ll_backend.call_gen.
-:- import_module ll_backend.liveness.
 :- import_module ll_backend.live_vars.
+:- import_module ll_backend.liveness.
 :- import_module mdbcomp.prim_data.
-:- import_module mdbcomp.trace_counts.
 :- import_module mdbcomp.program_representation.
+:- import_module mdbcomp.trace_counts.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_mode.
 :- import_module parse_tree.prog_type.
@@ -137,6 +137,7 @@
 :- import_module maybe.
 :- import_module multi_map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/type_class_info.m b/compiler/type_class_info.m
index ccd86e276..f8ce9c634 100644
--- a/compiler/type_class_info.m
+++ b/compiler/type_class_info.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 2003-2006 The University of Melbourne.
+% Copyright (C) 2003-2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -49,14 +49,13 @@
 :- import_module hlds.hlds_data.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.hlds_rtti.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module term.
 :- import_module varset.
 
diff --git a/compiler/type_ctor_info.m b/compiler/type_ctor_info.m
index 83422530a..69e7ffc13 100644
--- a/compiler/type_ctor_info.m
+++ b/compiler/type_ctor_info.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %---------------------------------------------------------------------------%
-% Copyright (C) 1996-2009 The University of Melbourne.
+% Copyright (C) 1996-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -77,7 +77,6 @@
 :- import_module hlds.pred_table.
 :- import_module hlds.special_pred.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.
@@ -93,6 +92,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/type_util.m b/compiler/type_util.m
index e624e0e35..34457b8a4 100644
--- a/compiler/type_util.m
+++ b/compiler/type_util.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1994-2009 The University of Melbourne.
+% Copyright (C) 1994-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -349,7 +349,6 @@
 :- import_module backend_libs.
 :- import_module backend_libs.foreign.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module parse_tree.builtin_lib_types.
@@ -361,6 +360,7 @@
 :- import_module char.
 :- import_module int.
 :- import_module map.
+:- import_module require.
 :- import_module set.
 :- import_module svset.
 :- import_module term.
diff --git a/compiler/typecheck.m b/compiler/typecheck.m
index d6be27823..cf11fe83f 100644
--- a/compiler/typecheck.m
+++ b/compiler/typecheck.m
@@ -116,7 +116,6 @@
 :- import_module hlds.pred_table.
 :- import_module hlds.special_pred.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.
@@ -136,6 +135,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module set_tree234.
 :- import_module std_util.
diff --git a/compiler/typecheck_errors.m b/compiler/typecheck_errors.m
index 8220ad3ab..ad6ae17e2 100644
--- a/compiler/typecheck_errors.m
+++ b/compiler/typecheck_errors.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2009 The University of Melbourne.
+% Copyright (C) 2005-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -106,7 +106,6 @@
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.pred_table.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module parse_tree.mercury_to_mercury.
 :- import_module parse_tree.modules.
@@ -122,6 +121,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module solutions.
 :- import_module string.
diff --git a/compiler/typecheck_info.m b/compiler/typecheck_info.m
index f4c84f3ed..b85e98f38 100644
--- a/compiler/typecheck_info.m
+++ b/compiler/typecheck_info.m
@@ -370,7 +370,6 @@
 
 :- import_module check_hlds.type_util.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.file_util.
 :- import_module libs.globals.
 :- import_module libs.options.
@@ -381,6 +380,7 @@
 :- import_module assoc_list.
 :- import_module int.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module set.
 :- import_module svmap.
diff --git a/compiler/unify_gen.m b/compiler/unify_gen.m
index db4016d7b..8c73566e4 100644
--- a/compiler/unify_gen.m
+++ b/compiler/unify_gen.m
@@ -69,7 +69,6 @@
 :- import_module hlds.hlds_out.hlds_out_util.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.hlds_rtti.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module ll_backend.code_util.
@@ -89,6 +88,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/unify_proc.m b/compiler/unify_proc.m
index 7174834bb..286891bf4 100644
--- a/compiler/unify_proc.m
+++ b/compiler/unify_proc.m
@@ -147,7 +147,6 @@
 :- import_module hlds.quantification.
 :- import_module hlds.special_pred.
 :- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -161,6 +160,7 @@
 :- import_module int.
 :- import_module map.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/unique_modes.m b/compiler/unique_modes.m
index 7fd449250..30e72f40a 100644
--- a/compiler/unique_modes.m
+++ b/compiler/unique_modes.m
@@ -91,8 +91,6 @@
 :- import_module check_hlds.modecheck_util.
 :- import_module check_hlds.modes.
 :- import_module hlds.instmap.
-:- import_module libs.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_mode.
@@ -103,6 +101,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module term.
 
diff --git a/compiler/unneeded_code.m b/compiler/unneeded_code.m
index 5bc687b33..e7c54f30b 100644
--- a/compiler/unneeded_code.m
+++ b/compiler/unneeded_code.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2000-2009 The University of Melbourne.
+% Copyright (C) 2000-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -83,7 +83,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.passes_aux.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.program_representation.
@@ -98,6 +97,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/untupling.m b/compiler/untupling.m
index 1490076cf..51050acf1 100644
--- a/compiler/untupling.m
+++ b/compiler/untupling.m
@@ -107,7 +107,6 @@
 :- import_module hlds.hlds_goal.
 :- import_module hlds.hlds_pred.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module mdbcomp.prim_data.
 :- import_module parse_tree.prog_data.
 :- import_module parse_tree.prog_mode.
@@ -121,6 +120,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module svvarset.
diff --git a/compiler/unused_args.m b/compiler/unused_args.m
index 33739d6f5..12a4cce36 100644
--- a/compiler/unused_args.m
+++ b/compiler/unused_args.m
@@ -97,7 +97,6 @@
 :- import_module hlds.instmap.
 :- import_module hlds.pred_table.
 :- import_module hlds.quantification.
-:- import_module libs.compiler_util.
 :- import_module libs.globals.
 :- import_module libs.options.
 :- import_module mdbcomp.prim_data.
@@ -114,6 +113,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 :- import_module svmap.
diff --git a/compiler/use_local_vars.m b/compiler/use_local_vars.m
index e59da69e7..6c97b1a25 100644
--- a/compiler/use_local_vars.m
+++ b/compiler/use_local_vars.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001-2009 The University of Melbourne.
+% Copyright (C) 2001-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -82,7 +82,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.basic_block.
 :- import_module ll_backend.code_util.
 :- import_module ll_backend.exprn_aux.
@@ -95,6 +94,7 @@
 :- import_module map.
 :- import_module maybe.
 :- import_module pair.
+:- import_module require.
 :- import_module set.
 :- import_module string.
 
diff --git a/compiler/var_locn.m b/compiler/var_locn.m
index 2132c644b..1c4c425dc 100644
--- a/compiler/var_locn.m
+++ b/compiler/var_locn.m
@@ -371,7 +371,6 @@
 
 :- import_module backend_libs.builtin_ops.
 :- import_module check_hlds.type_util.
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module ll_backend.code_util.
 :- import_module ll_backend.exprn_aux.
@@ -380,6 +379,7 @@
 :- import_module getopt_io.
 :- import_module int.
 :- import_module pair.
+:- import_module require.
 :- import_module string.
 :- import_module svmap.
 :- import_module term.
diff --git a/compiler/wrap_blocks.m b/compiler/wrap_blocks.m
index 2757eb444..6feba1fbd 100644
--- a/compiler/wrap_blocks.m
+++ b/compiler/wrap_blocks.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001, 2003, 2005-2007 The University of Melbourne.
+% Copyright (C) 2001, 2003, 2005-2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -34,12 +34,12 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.opt_util.
 
 :- import_module bool.
 :- import_module int.
 :- import_module pair.
+:- import_module require.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/write_deps_file.m b/compiler/write_deps_file.m
index 4bed877ba..f1301ce91 100644
--- a/compiler/write_deps_file.m
+++ b/compiler/write_deps_file.m
@@ -81,7 +81,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module libs.options.
 :- import_module make.                      % undesirable dependency
 :- import_module parse_tree.file_names.
@@ -97,8 +96,9 @@
 :- import_module dir.
 :- import_module library.
 :- import_module map.
-:- import_module string.
 :- import_module pair.
+:- import_module require.
+:- import_module string.
 
 %-----------------------------------------------------------------------------%
 
diff --git a/compiler/x86_64_out.m b/compiler/x86_64_out.m
index c36d36b5f..8cff8ff99 100644
--- a/compiler/x86_64_out.m
+++ b/compiler/x86_64_out.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007 The University of Melbourne.
+% Copyright (C) 2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -43,7 +43,6 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
 :- import_module ll_backend.x86_64_regs.
 
 :- import_module bool.
@@ -51,6 +50,7 @@
 :- import_module int.
 :- import_module list.
 :- import_module maybe.
+:- import_module require.
 :- import_module stream.string_writer.
 :- import_module string.
 :- import_module type_desc.
diff --git a/compiler/x86_64_regs.m b/compiler/x86_64_regs.m
index 3987f7d3b..e8d797fa1 100644
--- a/compiler/x86_64_regs.m
+++ b/compiler/x86_64_regs.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2007 The University of Melbourne.
+% Copyright (C) 2007, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -45,13 +45,14 @@
     % is the slot in the fake reg array given by the argument.
     %
 :- type reg_locn
-	--->	actual(x86_64_reg)
-	;		virtual(int).		% Index into fake reg array.
+    --->    actual(x86_64_reg)
+    ;       virtual(int).       % Index into fake reg array.
 
     % Create an association list of lvals and reg_lcons. This is identical to 
     % the one defined in runtime/machdeps/x86_64_regs.h.
     %
-:- pred default_x86_64_reg_mapping(assoc_list(llds.lval, reg_locn)::out) is det. 
+:- pred default_x86_64_reg_mapping(assoc_list(llds.lval, reg_locn)::out)
+    is det. 
 
     % Create a reg_map given an association list of lvals and reg_locns.
     % Throws an exception if an l-value in the association list does not
@@ -89,27 +90,26 @@
 
 :- implementation.
 
-:- import_module libs.compiler_util.
-
 :- import_module bool.
+:- import_module io.
 :- import_module list. 
 :- import_module map.
 :- import_module pair. 
+:- import_module require.
 :- import_module string. 
 
-:- import_module io.
-
 %----------------------------------------------------------------------------%
 % 
 % LLDS -> x86_64 register mapping. 
 %
 
 :- type reg_map
-	--->	reg_map(
-				scratch_reg_info        :: list(x86_64_reg), 
+    --->    reg_map(
                 % A list of unused scratch registers.
-				map(llds.lval, reg_locn)
-			    % Mapping lval to an actual or virtual register. 
+                scratch_reg_info        :: list(x86_64_reg), 
+
+                % Mapping lval to an actual or virtual register. 
+                lval_reg_map            :: map(llds.lval, reg_locn)
             ).
 
 %----------------------------------------------------------------------------%
diff --git a/deep_profiler/analysis_utils.m b/deep_profiler/analysis_utils.m
index 2e4631b2e..afd4726e4 100644
--- a/deep_profiler/analysis_utils.m
+++ b/deep_profiler/analysis_utils.m
@@ -31,22 +31,22 @@
 :- import_module set.
 
 %----------------------------------------------------------------------------%
-    
+
     % Instead of using the clique report above to find proc dynamics for a
     % clique, use this as it is much faster.
     %
-:- pred find_clique_first_and_other_procs(deep::in, clique_ptr::in, 
+:- pred find_clique_first_and_other_procs(deep::in, clique_ptr::in,
     maybe(proc_dynamic_ptr)::out, list(proc_dynamic_ptr)::out) is det.
 
 %----------------------------------------------------------------------------%
-    
+
     % Lookup a procedure representation from the deep structure.
     %
     % (Perhaps this should be a new report).
     %
-:- pred deep_get_maybe_procrep(deep::in, proc_static_ptr::in, 
+:- pred deep_get_maybe_procrep(deep::in, proc_static_ptr::in,
     maybe_error(proc_rep)::out) is det.
-    
+
 %----------------------------------------------------------------------------%
 
 :- type cost_and_callees
@@ -66,7 +66,7 @@
     --->    first_order_call
     ;       higher_order_call.
 
-:- pred build_call_site_cost_and_callee_map(deep::in, 
+:- pred build_call_site_cost_and_callee_map(deep::in,
     pair(call_site_static_ptr, call_site_array_slot)::in,
     map(goal_path, cost_and_callees)::in, map(goal_path, cost_and_callees)::out)
     is det.
@@ -77,10 +77,10 @@
     % current call to this procedure had a particular cost.
     %
 :- pred build_recursive_call_site_cost_map(deep, clique_ptr,
-    proc_dynamic_ptr, recursion_type, maybe(recursion_depth), 
+    proc_dynamic_ptr, recursion_type, maybe(recursion_depth),
     maybe_error(map(goal_path, cs_cost_csq))) is det.
 :- mode build_recursive_call_site_cost_map(in, in, in,
-    in(recursion_type_known_costs), in(maybe_yes(ground)), 
+    in(recursion_type_known_costs), in(maybe_yes(ground)),
     out(maybe_error_ok(ground))) is det.
 :- mode build_recursive_call_site_cost_map(in, in, in, in, in, out) is det.
 
@@ -90,8 +90,8 @@
     assoc_list(call_site_static_ptr, call_site_array_slot)::out) is det.
 
 %----------------------------------------------------------------------------%
-            
-:- pred cost_and_callees_is_recursive(clique_ptr::in, cost_and_callees::in) 
+
+:- pred cost_and_callees_is_recursive(clique_ptr::in, cost_and_callees::in)
     is semidet.
 
 %----------------------------------------------------------------------------%
@@ -154,9 +154,9 @@ build_call_site_cost_and_callee_map(Deep, CSSPtr - Slot, !CallSitesMap) :-
     (
         Slot = slot_normal(CSDPtr),
         ( valid_call_site_dynamic_ptr(Deep, CSDPtr) ->
-            call_site_dynamic_get_callee_and_costs(Deep, CSDPtr, Callee, 
+            call_site_dynamic_get_callee_and_costs(Deep, CSDPtr, Callee,
                 Own, Inherit),
-            CostCsq = build_cs_cost_csq(calls(Own), 
+            CostCsq = build_cs_cost_csq(calls(Own),
                 float(callseqs(Own) + inherit_callseqs(Inherit))),
             Callees = [Callee]
         ;
@@ -166,11 +166,11 @@ build_call_site_cost_and_callee_map(Deep, CSSPtr - Slot, !CallSitesMap) :-
     ;
         Slot = slot_multi(_, CSDPtrsArray),
         to_list(CSDPtrsArray, CSDPtrs),
-        map3(call_site_dynamic_get_callee_and_costs(Deep), CSDPtrs, 
+        map3(call_site_dynamic_get_callee_and_costs(Deep), CSDPtrs,
             Callees, Owns, Inherits),
         Own = sum_own_infos(Owns),
         Inherit = sum_inherit_infos(Inherits),
-        CostCsq = build_cs_cost_csq(calls(Own), 
+        CostCsq = build_cs_cost_csq(calls(Own),
             float(callseqs(Own) + inherit_callseqs(Inherit)))
     ),
     CostAndCallees = cost_and_callees(CostCsq, set(Callees), HigherOrder),
@@ -179,16 +179,16 @@ build_call_site_cost_and_callee_map(Deep, CSSPtr - Slot, !CallSitesMap) :-
     goal_path_from_string_det(CSS ^ css_goal_path, GoalPath),
     svmap.det_insert(GoalPath, CostAndCallees, !CallSitesMap).
 
-:- pred call_site_dynamic_get_callee_and_costs(deep::in, 
-    call_site_dynamic_ptr::in, callee::out, own_prof_info::out, 
+:- pred call_site_dynamic_get_callee_and_costs(deep::in,
+    call_site_dynamic_ptr::in, callee::out, own_prof_info::out,
     inherit_prof_info::out) is det.
 
-call_site_dynamic_get_callee_and_costs(Deep, CSDPtr, 
+call_site_dynamic_get_callee_and_costs(Deep, CSDPtr,
         callee(CalleeCliquePtr, CSDPtr), Own, Inherit) :-
     lookup_call_site_dynamics(Deep ^ call_site_dynamics, CSDPtr, CSD),
     lookup_csd_desc(Deep ^ csd_desc, CSDPtr, Inherit),
     PDPtr = CSD ^ csd_callee,
-    lookup_clique_index(Deep ^ clique_index, PDPtr, CalleeCliquePtr), 
+    lookup_clique_index(Deep ^ clique_index, PDPtr, CalleeCliquePtr),
     Own = CSD ^ csd_own_prof.
 
 :- pred call_site_kind_to_higher_order(call_site_kind_and_callee::in,
@@ -222,25 +222,25 @@ build_recursive_call_site_cost_map(Deep, CliquePtr, PDPtr, RecursionType,
             DepthI = recursion_depth_to_int(Depth)
         ;
             MaybeDepth = no,
-            error(this_file ++ "Expected valid depth for known recursion type")
+            unexpected($module,
+                "Expected valid depth for known recursion type")
         ),
-    
+
         get_recursive_calls_and_counts(Deep, CliquePtr, PDPtr,
             CallCountsMap),
         RecursiveCallSiteCostMap = map_values_only(
-            (func(Count) = 
+            (func(Count) =
                 build_cs_cost_csq_percall(float(Count), CostFn(DepthI))),
             CallCountsMap),
         MaybeRecursiveCallSiteCostMap = ok(RecursiveCallSiteCostMap),
-        
+
         trace [compile_time(flag("debug_recursive_call_costs")), io(!IO)] (
             format_recursive_call_site_cost_map(
                 RecursiveCallSiteCostMap, PrettyCostMapCord),
             PrettyCostMap = append_list(cord.list(PrettyCostMapCord)),
-            io.format("D: In clique %s recursive call site cost map"
-                    ++ " is:\n%s\n",
-                [s(string(CliquePtr)), s(PrettyCostMap)],
-                !IO),
+            io.format(
+                "D: In clique %s recursive call site cost map is:\n%s\n",
+                [s(string(CliquePtr)), s(PrettyCostMap)], !IO),
             io.flush_output(!IO)
         )
     ;
@@ -264,19 +264,20 @@ build_recursive_call_site_cost_map(Deep, CliquePtr, PDPtr, RecursionType,
         MaybeRecursiveCallSiteCostMap = error(Error)
     ).
 
-:- pred get_recursive_calls_and_counts(deep::in, clique_ptr::in, 
+:- pred get_recursive_calls_and_counts(deep::in, clique_ptr::in,
     proc_dynamic_ptr::in, map(goal_path, int)::out) is det.
 
 get_recursive_calls_and_counts(Deep, CliquePtr, PDPtr, CallCountsMap) :-
     proc_dynamic_paired_call_site_slots(Deep, PDPtr, SiteSlots),
-    foldl(build_recursive_call_site_counts_map(Deep, CliquePtr), SiteSlots, 
+    foldl(build_recursive_call_site_counts_map(Deep, CliquePtr), SiteSlots,
         map.init, CallCountsMap).
 
-:- pred build_recursive_call_site_counts_map(deep::in, clique_ptr::in, 
+:- pred build_recursive_call_site_counts_map(deep::in, clique_ptr::in,
     pair(call_site_static_ptr, call_site_array_slot)::in,
     map(goal_path, int)::in, map(goal_path, int)::out) is det.
 
-build_recursive_call_site_counts_map(Deep, CliquePtr, CSSPtr - CSDSlot, !Map) :-
+build_recursive_call_site_counts_map(Deep, CliquePtr, CSSPtr - CSDSlot,
+        !Map) :-
     (
         CSDSlot = slot_normal(CSDPtr),
         ( valid_call_site_dynamic_ptr(Deep, CSDPtr) ->
@@ -289,7 +290,7 @@ build_recursive_call_site_counts_map(Deep, CliquePtr, CSSPtr - CSDSlot, !Map) :-
             )
         ;
             Recursive = no,
-            Count = 0 
+            Count = 0
         )
     ;
         CSDSlot = slot_multi(_, CSDPtrs),
@@ -319,7 +320,7 @@ build_recursive_call_site_counts_map(Deep, CliquePtr, CSSPtr - CSDSlot, !Map) :-
 maybe_equals_or_is_no(_, no).
 maybe_equals_or_is_no(X, yes(X)).
 
-:- pred call_site_dynamic_get_count_and_callee(deep::in, 
+:- pred call_site_dynamic_get_count_and_callee(deep::in,
     call_site_dynamic_ptr::in, int::out, maybe(clique_ptr)::out) is det.
 
 call_site_dynamic_get_count_and_callee(Deep, CSDPtr, Count, MaybeCallee) :-
@@ -332,13 +333,13 @@ call_site_dynamic_get_count_and_callee(Deep, CSDPtr, Count, MaybeCallee) :-
         MaybeCallee = no
     ).
 
-:- pred format_recursive_call_site_cost_map(map(goal_path, cs_cost_csq)::in, 
+:- pred format_recursive_call_site_cost_map(map(goal_path, cs_cost_csq)::in,
     cord(string)::out) is det.
 
 format_recursive_call_site_cost_map(Map, Result) :-
     map.foldl(format_recursive_call_site_cost, Map, cord.empty, Result).
 
-:- pred format_recursive_call_site_cost(goal_path::in, cs_cost_csq::in, 
+:- pred format_recursive_call_site_cost(goal_path::in, cs_cost_csq::in,
     cord(string)::in, cord(string)::out) is det.
 
 format_recursive_call_site_cost(GoalPath, Cost, !Result) :-
@@ -372,6 +373,6 @@ cost_and_callees_is_recursive(ParentCliquePtr, CostAndCallees) :-
 
 :- func this_file = string.
 
-this_file = "analysis_utils.m: ".
+this_file = "analysis_utils.m".
 
 %----------------------------------------------------------------------------%
diff --git a/deep_profiler/array_util.m b/deep_profiler/array_util.m
index 7a7b7557d..704fea592 100644
--- a/deep_profiler/array_util.m
+++ b/deep_profiler/array_util.m
@@ -90,7 +90,7 @@
     % Performs a foldl3 on all the elements of the given array, starting at
     % index 1.
     %
-:- pred array_foldl3_from_1(pred(int, T, U, U, V, V, W, W), array(T), U, U, 
+:- pred array_foldl3_from_1(pred(int, T, U, U, V, V, W, W), array(T), U, U,
     V, V, W, W).
 :- mode array_foldl3_from_1(pred(in, in, array_di, array_uo,
     array_di, array_uo, array_di, array_uo) is det,
@@ -214,7 +214,7 @@ array_foldl3_from_1(P, Array, !A, !B, !C) :-
 
 :- pred do_array_foldl3(int, int, pred(int, T, U, U, V, V, W, W), array(T),
     U, U, V, V, W, W).
-:- mode do_array_foldl3(in, in, pred(in, in, array_di, array_uo, 
+:- mode do_array_foldl3(in, in, pred(in, in, array_di, array_uo,
     array_di, array_uo, array_di, array_uo) is det, in,
     array_di, array_uo, array_di, array_uo, array_di, array_uo) is det.
 
diff --git a/deep_profiler/branch_and_bound.m b/deep_profiler/branch_and_bound.m
index b99d5b711..8bb5fa403 100644
--- a/deep_profiler/branch_and_bound.m
+++ b/deep_profiler/branch_and_bound.m
@@ -12,7 +12,7 @@
 % This module contains a generic branch and bound solver.  It is designed to be
 % generic and easy to use.  To use it write non-deterministic search code that
 % uses test_incomplete_solution after every choice point.  Call this code using
-% branch_and_bound. 
+% branch_and_bound.
 %
 % This module may be compiled with the debug_branch_and_bound trace flag to
 % enable the debugging trace goals.
@@ -62,7 +62,7 @@
     %
 :- pred branch_and_bound(impure pred(bnb_state(T), T),
     func(T) = float, set(T), bnb_profile).
-:- mode branch_and_bound(pred(in, out) is nondet, 
+:- mode branch_and_bound(pred(in, out) is nondet,
     func(in) = out is det, out, out) is det.
 
     % test_incomplete_solution(State, PartialSolution).
@@ -114,7 +114,7 @@
 :- import_module unit.
 
 %-----------------------------------------------------------------------------%
-    
+
     % The best solutions found so far and the value of the objective
     % function for these solutions.
     %
@@ -148,13 +148,14 @@ branch_and_bound(Generator, ObjectiveFn, BestSolutions, Profile) :-
     ),
     Profile = Profile0 ^ bnbp_time_msecs := Time.
 
-:- pred branch_and_bound_2(impure pred(bnb_state(T), T), 
-    func(T) = float, unit, 
+:- pred branch_and_bound_2(impure pred(bnb_state(T), T),
+    func(T) = float, unit,
     pair(set(T), bnb_profile)).
-:- mode branch_and_bound_2(pred(in, out) is nondet, 
+:- mode branch_and_bound_2(pred(in, out) is nondet,
     func(in) = out is det, in, out) is det.
 
-branch_and_bound_2(Generator, ObjectiveFn, unit, FinalBestSolutions - FinalProfile) :-
+branch_and_bound_2(Generator, ObjectiveFn, unit,
+        FinalBestSolutions - FinalProfile) :-
     % Use a failure driven loop to implement a branch and bound solver.
     promise_pure (
         trace [compile_time(flag("debug_branch_and_bound")), io(!IO)] (
@@ -167,7 +168,7 @@ branch_and_bound_2(Generator, ObjectiveFn, unit, FinalBestSolutions - FinalProfi
         (
             impure Generator(State, CurrentSolution),
 
-            impure test_complete_solution(State, CurrentSolution), 
+            impure test_complete_solution(State, CurrentSolution),
             trace [compile_time(flag("debug_branch_and_bound")), io(!IO)] (
                 CurrentObjective = ObjectiveFn(CurrentSolution),
                 io.format(
@@ -178,13 +179,13 @@ branch_and_bound_2(Generator, ObjectiveFn, unit, FinalBestSolutions - FinalProfi
 
             semidet_fail
         ->
-            error(this_file ++ "Failure driven loop must fail")
+            unexpected($module, "Failure driven loop must fail")
         ;
             true
         ),
 
         % Return results.
-        impure get_mutvar(BestSolutionsMutvar, FinalBestSolutions0), 
+        impure get_mutvar(BestSolutionsMutvar, FinalBestSolutions0),
         impure get_mutvar(ProfileMutvar, FinalProfile),
         trace [compile_time(flag("debug_branch_and_bound")), io(!IO)] (
             io.write_string("D: Branch and bound loop finished\n", !IO),
@@ -206,13 +207,13 @@ branch_and_bound_2(Generator, ObjectiveFn, unit, FinalBestSolutions - FinalProfi
     % True of Solution is the best or equal best solution so far.
     %
     % The current best solutions are updated.
-    % 
+    %
 :- impure pred test_complete_solution(bnb_state(T)::in, T::in) is semidet.
 
-test_complete_solution(State, CurrentSolution) :- 
+test_complete_solution(State, CurrentSolution) :-
     State = bnb_state(BestSolutionsMutvar, ObjectiveFn, ProfileMutvar),
     CurrentObjective = ObjectiveFn(CurrentSolution),
-   
+
     impure get_mutvar(BestSolutionsMutvar, BestSolutions0),
     impure get_mutvar(ProfileMutvar, Profile0),
     (
@@ -356,7 +357,7 @@ profile_num_alternatives(Profile, Open, Closed) :-
 
 :- func this_file = string.
 
-this_file = "branch_and_bound.m: ".
+this_file = "branch_and_bound.m".
 
 %-----------------------------------------------------------------------------%
 :- end_module branch_and_bound.
diff --git a/deep_profiler/callgraph.m b/deep_profiler/callgraph.m
index c761fd71f..7461cc88a 100644
--- a/deep_profiler/callgraph.m
+++ b/deep_profiler/callgraph.m
@@ -57,11 +57,11 @@ find_cliques(InitDeep, BottomUpPDPtrCliqueList) :-
     % algorithm works bottom up.
     callgraph.foldl(accumulate_pdptr_lists, TopDownPDICliqueList,
         [], BottomUpPDPtrCliqueList).
-    
+
     % This version of foldl is safer when tail recursion isn't available.
     %
-:- pred foldl(pred(X, A, A), list(X), A, A).
-:- mode foldl(pred(in, in, out) is det, in, in, out) is det.
+:- pred foldl(pred(X, A, A)::in(pred(in, in, out) is det), list(X)::in,
+    A::in, A::out) is det.
 
 foldl(P, !.L, !A) :-
     foldl_2(100000, P, !L, !A),
@@ -72,8 +72,8 @@ foldl(P, !.L, !A) :-
         callgraph.foldl(P, !.L, !A)
     ).
 
-:- pred foldl_2(int, pred(X, A, A), list(X), list(X), A, A).
-:- mode foldl_2(in, pred(in, in, out) is det, in, out, in, out) is det.
+:- pred foldl_2(int::in, pred(X, A, A)::in(pred(in, in, out) is det),
+    list(X)::in, list(X)::out, A::in, A::out) is det.
 
 foldl_2(Depth, P, !Xs, !A) :-
     ( Depth > 0 ->
diff --git a/deep_profiler/canonical.m b/deep_profiler/canonical.m
index be5def3a4..d343c0317 100644
--- a/deep_profiler/canonical.m
+++ b/deep_profiler/canonical.m
@@ -54,10 +54,10 @@
 
 :- type redirect
     --->    redirect(
-                csd_redirect :: array(call_site_dynamic_ptr),
-                             % index: call_site_dynamic_ptr
-                pd_redirect  :: array(proc_dynamic_ptr)
-                             % index: proc_dynamic_ptr
+                csd_redirect        :: array(call_site_dynamic_ptr),
+                                    % index: call_site_dynamic_ptr
+                pd_redirect         :: array(proc_dynamic_ptr)
+                                    % index: proc_dynamic_ptr
             ).
 
 canonicalize_cliques(!InitDeep) :-
@@ -262,7 +262,7 @@ merge_proc_dynamics(MergeInfo, Clique, CandidatePDPtrs, ChosenPDPtr,
         % special calls, but only before we added callcode to the
         % unify/compare routines of builtin types.
         % ChosenPDPtr = proc_dynamic_ptr(0),
-        error("merge_proc_dynamics: no valid pdptrs")
+        unexpected($module, $pred, "no valid pdptrs")
     ).
 
 :- pred merge_proc_dynamic_slots(merge_info::in, int::in,
@@ -496,7 +496,7 @@ lookup_normal_sites([RestArray | RestArrays], SlotNum, [CSDPtr | CSDPtrs]) :-
         Slot = slot_normal(CSDPtr)
     ;
         Slot = slot_multi(_, _),
-        error("lookup_normal_sites: found slot_multi")
+        unexpected($module, $pred, "found slot_multi")
     ),
     lookup_normal_sites(RestArrays, SlotNum, CSDPtrs).
 
@@ -508,7 +508,7 @@ lookup_multi_sites([RestArray | RestArrays], SlotNum, [CSDList | CSDLists]) :-
     array.lookup(RestArray, SlotNum, Slot),
     (
         Slot = slot_normal(_),
-        error("lookup_multi_sites: found normal")
+        unexpected($module, $pred, "found normal")
     ;
         Slot = slot_multi(_, CSDArray),
         array.to_list(CSDArray, CSDList)
@@ -531,7 +531,7 @@ record_pd_redirect(RestPDPtrs, PrimePDPtr, !Redirect) :-
     ( OldRedirect = proc_dynamic_ptr(0) ->
         record_pd_redirect_2(RestPDPtrs, PrimePDPtr, !Redirect)
     ;
-        error("record_pd_redirect: prime is redirected")
+        unexpected($module, $pred, "prime is redirected")
     ).
 
 :- pred record_pd_redirect_2(list(proc_dynamic_ptr)::in, proc_dynamic_ptr::in,
@@ -545,7 +545,7 @@ record_pd_redirect_2([RestPDPtr | RestPDPtrs], PrimePDPtr, !Redirect) :-
         set_pd_redirect(u(ProcRedirect0), RestPDPtr, PrimePDPtr,
             ProcRedirect)
     ;
-        error("record_pd_redirect_2: already redirected")
+        unexpected($module, $pred, "already redirected")
     ),
     !:Redirect = !.Redirect ^ pd_redirect := ProcRedirect,
     record_pd_redirect_2(RestPDPtrs, PrimePDPtr, !Redirect).
@@ -566,7 +566,7 @@ record_csd_redirect(RestCSDPtrs, PrimeCSDPtr, !Redirect) :-
     ( OldRedirect = call_site_dynamic_ptr(0) ->
         record_csd_redirect_2(RestCSDPtrs, PrimeCSDPtr, !Redirect)
     ;
-        error("record_pd_redirect: prime is redirected")
+        unexpected($module, $pred, "prime is redirected")
     ).
 
 :- pred record_csd_redirect_2(list(call_site_dynamic_ptr)::in,
@@ -580,7 +580,7 @@ record_csd_redirect_2([RestCSDPtr | RestCSDPtrs], PrimeCSDPtr, !Redirect) :-
         set_csd_redirect(u(CallSiteRedirect0), RestCSDPtr, PrimeCSDPtr,
             CallSiteRedirect)
     ;
-        error("record_csd_redirect_2: already redirected")
+        unexpected($module, $pred, "already redirected")
     ),
     !:Redirect = !.Redirect ^ csd_redirect := CallSiteRedirect,
     record_csd_redirect_2(RestCSDPtrs, PrimeCSDPtr, !Redirect).
@@ -851,7 +851,7 @@ do_merge_profiles(BaseInitDeep, OtherInitDeeps, MergedInitDeep) :-
     extract_num_callseqs(BaseInitDeep, BaseNumCallSeqs),
     list.map(extract_num_callseqs, OtherInitDeeps, OtherNumCallSeqs),
     list.foldl(int_add, OtherNumCallSeqs, BaseNumCallSeqs, ConcatNumCallSeqs),
-    
+
     % The program names are not checked. The new profile is named after the
     % base profile.
     BaseProgramName = BaseInitDeep ^ init_profile_stats ^ prs_program_name,
@@ -862,7 +862,7 @@ do_merge_profiles(BaseInitDeep, OtherInitDeeps, MergedInitDeep) :-
     ConcatFlags = BaseFlags ^ df_canonical_flag := is_canonical,
     ConcatProfileStats = profile_stats(BaseProgramName,
         ConcatMaxCSD, BaseMaxCSS, ConcatMaxPD, BaseMaxPS, ConcatNumCallSeqs,
-        BaseTicksPerSec, InstrumentQuanta, UserQuanta, ConcatFlags), 
+        BaseTicksPerSec, InstrumentQuanta, UserQuanta, ConcatFlags),
     % The root part is a temporary lie.
     MergedInitDeep = initial_deep(ConcatProfileStats,
         BaseInitDeep ^ init_root,
diff --git a/deep_profiler/conf.m b/deep_profiler/conf.m
index b117d9c44..93aea3e97 100644
--- a/deep_profiler/conf.m
+++ b/deep_profiler/conf.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001-2002, 2004-2008 The University of Melbourne.
+% Copyright (C) 2001-2002, 2004-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -52,7 +52,7 @@
 make_pipe_cmd(PipeName) = Cmd :-
     mkfifo_cmd(CmdName),
     ( CmdName = "" ->
-        error("make_pipe_cmd: do not know what command to use")
+        unexpected($module, $pred, "do not know what command to use")
     ;
         string.format("%s %s", [s(CmdName), s(PipeName)], Cmd)
     ).
@@ -102,24 +102,27 @@ server_name_2(ServerName, !IO) :-
                     ->
                         ServerName = ServerNamePrime
                     ;
-                        error("malformed server name")
+                        unexpected($module, $pred, "malformed server name")
                     )
                 ;
                     TmpReadRes = error(_, _),
-                    error("cannot read server's name")
+                    unexpected($module, $pred, "cannot read server's name")
                 ),
                 io.close_input(TmpStream, !IO)
             ;
                 TmpRes = error(_),
-                error("cannot open file to find the server's name")
+                unexpected($module, $pred,
+                    "cannot open file to find the server's name")
             ),
             io.remove_file(TmpFile, _, !IO)
         ;
-            error("cannot execute cmd to find the server's name")
+            unexpected($module, $pred,
+                "cannot execute cmd to find the server's name")
         )
     ;
         Res1 = error(_),
-        error("cannot execute cmd to find the server's name")
+        unexpected($module, $pred,
+            "cannot execute cmd to find the server's name")
     ).
 
 :- pred maybe_server_port(maybe(string)::out, io::di, io::uo) is det.
diff --git a/deep_profiler/coverage.m b/deep_profiler/coverage.m
index 908f2551e..31ad02ba2 100644
--- a/deep_profiler/coverage.m
+++ b/deep_profiler/coverage.m
@@ -147,7 +147,7 @@ get_coverage_after_det(Coverage, After) :-
 :- pred complete_coverage_error is erroneous.
 
 complete_coverage_error :-
-    error(this_file ++ "Expected complete coverage information").
+    unexpected($module, $pred, "Expected complete coverage information").
 
 %-----------------------------------------------------------------------------%
 
@@ -156,7 +156,7 @@ coverage_point_arrays_to_list(StaticArray, DynamicArray, CoveragePoints) :-
     ( array.bounds(DynamicArray, Min, Max) ->
         true
     ;
-        error("coverage_point_arrays_to_list: Bounds do not match")
+        unexpected($module, $pred, "bounds do not match")
     ),
     coverage_point_arrays_to_list_2(Min, Max, StaticArray, DynamicArray,
         [], CoveragePoints).
@@ -307,7 +307,8 @@ goal_annotate_coverage(Info, GoalPath, Before, After, Goal0, Goal) :-
                   "Coverage before call doesn't match calls port on call site"),
                 After0 = after_coverage(Exits)
             ;
-                error("Couldn't look up call site for port counts GP: " ++
+                unexpected($module, $pred,
+                    "Couldn't look up call site for port counts GP: " ++
                     goal_path_to_string(GoalPath))
             )
         ;
@@ -351,16 +352,18 @@ goal_annotate_coverage(Info, GoalPath, Before, After, Goal0, Goal) :-
         ( check_coverage_complete(GoalCoverage, GoalExpr) ->
             true
         ;
-            error(string.format("check_coverage_complete failed\n" ++
-                "\tCoverage: %s\n\tGoalPath: %s\n\tProc: %s\n",
-                [s(string(GoalCoverage)), 
-                 s(goal_path_to_string(GoalPath)),
-                 s(string(Info ^ cri_proc))]))
+            error(
+                string.format("check_coverage_complete failed\n" ++
+                    "\tCoverage: %s\n\tGoalPath: %s\n\tProc: %s\n",
+                    [s(string(GoalCoverage)), 
+                     s(goal_path_to_string(GoalPath)),
+                     s(string(Info ^ cri_proc))]))
         ),
         ( check_coverage_regarding_detism(GoalCoverage, Detism) ->
             true
         ;
-            error(string.format("check_coverage_regarding_detism failed: %s %s",
+            error(
+                string.format("check_coverage_regarding_detism failed: %s %s",
                     [s(string(GoalCoverage)), s(string(Detism))]))
         )
     ).
diff --git a/deep_profiler/create_report.m b/deep_profiler/create_report.m
index da2352561..c7ab7f4f8 100644
--- a/deep_profiler/create_report.m
+++ b/deep_profiler/create_report.m
@@ -52,14 +52,14 @@
     %
 :- pred create_dynamic_procrep_coverage_report(deep::in,
     proc_dynamic_ptr::in, maybe_error(procrep_coverage_info)::out) is det.
-    
+
     % Create a top procs report, from the given data with the specified
     % parameters.
     %
 :- pred create_top_procs_report(deep::in, display_limit::in, cost_kind::in,
     include_descendants::in, measurement_scope::in,
     maybe_error(top_procs_report)::out) is det.
-    
+
     % Create a clique report, from the given data with the specified
     % parameters.
     %
@@ -214,7 +214,7 @@ create_report(Cmd, Deep, Report) :-
         Report = report_call_site_dynamic_var_use(MaybeVarUse)
     ;
         Cmd = deep_cmd_restart,
-        error("create_report/3", "unexpected restart command")
+        unexpected($module, $pred, "restart command")
     ).
 
 %-----------------------------------------------------------------------------%
@@ -297,7 +297,7 @@ find_start_of_action_callee(Percent, RowData, !ActionCliquePtrs) :-
     MaybeTotalPerf = RowData ^ perf_row_maybe_total,
     (
         MaybeTotalPerf = no,
-        error("find_start_of_action_callee: no total perf")
+        unexpected($module, $pred, "no total perf")
     ;
         MaybeTotalPerf = yes(TotalPerf),
         CallSeqsPercent = TotalPerf ^ perf_row_callseqs_percent,
@@ -400,7 +400,7 @@ proc_group_contains(EntryPDPtr, _ - PDPtrs) :-
 create_clique_proc_report(Deep, CliquePtr, PSPtr - PDPtrs, CliqueProcReport) :-
     (
         PDPtrs = [],
-        error("create_clique_proc_report", "PDPtrs = []")
+        unexpected($module, $pred, "PDPtrs = []")
     ;
         PDPtrs = [FirstPDPtr | LaterPDPtrs],
         ProcDesc = describe_proc(Deep, PSPtr),
@@ -436,7 +436,7 @@ create_clique_proc_dynamic_report(Deep, _CliquePtr, ProcDesc, PDPtr,
         CliquePDReport = clique_proc_dynamic_report(PDRowData,
             CliqueCallSiteReports)
     ;
-        error("invalid proc_dynamic index")
+        unexpected($module, $pred, "invalid proc_dynamic index")
     ).
 
 :- pred create_child_call_site_reports(deep::in, proc_dynamic_ptr::in,
@@ -464,7 +464,7 @@ create_child_call_site_report(Deep, Pair, CliqueCallSiteReport) :-
             CallSiteArraySlot = slot_normal(CSDPtr)
         ;
             CallSiteArraySlot = slot_multi(_, _),
-            error("create_child_call_site_report: normal_call error")
+            unexpected($module, $pred, "normal_call is multi")
         ),
         ( valid_call_site_dynamic_ptr(Deep, CSDPtr) ->
             create_callee_clique_perf_row_data(Deep, CSDPtr, Own, Desc,
@@ -491,7 +491,7 @@ create_child_call_site_report(Deep, Pair, CliqueCallSiteReport) :-
         ),
         (
             CallSiteArraySlot = slot_normal(_),
-            error("create_child_call_site_report: non-normal_call error")
+            unexpected($module, $pred, "non-normal_call is normal")
         ;
             CallSiteArraySlot = slot_multi(_IsZeroed, CSDPtrsArray),
             array.to_list(CSDPtrsArray, CSDPtrs)
@@ -704,7 +704,7 @@ gather_getters_setters(Deep, PSPtr, !GSDSRawMap) :-
                         ( FieldData0 = gs_field_both(_, _, _)
                         ; FieldData0 = gs_field_getter(_)
                         ),
-                        error("gather_getters_setters: redundant getter")
+                        unexpected($module, $pred, "redundant getter")
                     ;
                         FieldData0 = gs_field_setter(SetterRawData),
                         FieldData = gs_field_both(RawData, SetterRawData, unit)
@@ -715,7 +715,7 @@ gather_getters_setters(Deep, PSPtr, !GSDSRawMap) :-
                         ( FieldData0 = gs_field_both(_, _, _)
                         ; FieldData0 = gs_field_setter(_)
                         ),
-                        error("gather_getters_setters: redundant setter")
+                        unexpected($module, $pred, "redundant setter")
                     ;
                         FieldData0 = gs_field_getter(GetterRawData),
                         FieldData = gs_field_both(GetterRawData, RawData, unit)
@@ -743,7 +743,8 @@ gather_getters_setters(Deep, PSPtr, !GSDSRawMap) :-
 :- pred is_getter_or_setter(string_proc_label::in, getter_or_setter::out,
     data_struct_name::out, field_name::out) is semidet.
 
-is_getter_or_setter(StringProcLabel, GetterSetter, DataStructName, FieldName) :-
+is_getter_or_setter(StringProcLabel, GetterSetter, DataStructName,
+        FieldName) :-
     StringProcLabel = str_ordinary_proc_label(_PorF, DeclModule, DefModule,
         Name, Arity, _Mode),
     DeclModule = DefModule,
@@ -874,7 +875,7 @@ create_call_site_summary(Deep, CSSPtr) = CallSitePerf :-
             CallSiteCalleePerf = call_site_callee_perf(_, Own, Desc)
         ;
             CallSiteCalls = [_, _ | _],
-            error("create_call_site_summary: >1 proc called at site")
+            unexpected($module, $pred, ">1 proc called at normal site")
         ),
         own_and_inherit_to_perf_row_data(Deep, CallSiteDesc, Own, Desc,
             SummaryRowData),
@@ -1105,13 +1106,13 @@ create_static_procrep_coverage_report(Deep, PSPtr, MaybeReport) :-
         deep_lookup_ps_coverage(Deep, PSPtr, StaticCoverage),
         MaybeCoveragePoints =
             static_coverage_maybe_get_coverage_points(StaticCoverage),
-        
+
         % Gather call site information.
         deep_lookup_proc_statics(Deep, PSPtr, PS),
         CallSitesArray = PS ^ ps_sites,
         CallSitesMap = array.foldl(add_ps_calls_and_exits_to_map(Deep),
             CallSitesArray, map.init),
-        
+
         % Gather information about the procedure.
         deep_lookup_ps_own(Deep, PSPtr, Own),
 
@@ -1120,7 +1121,7 @@ create_static_procrep_coverage_report(Deep, PSPtr, MaybeReport) :-
     ;
         PSPtr = proc_static_ptr(PSId),
         MaybeReport = error(
-            format("Proc static pointer is invalid %d", [i(PSId)]))
+            string.format("Proc static pointer is invalid %d", [i(PSId)]))
     ).
 
 create_dynamic_procrep_coverage_report(Deep, PDPtr, MaybeReport) :-
@@ -1128,16 +1129,16 @@ create_dynamic_procrep_coverage_report(Deep, PDPtr, MaybeReport) :-
         deep_lookup_proc_dynamics(Deep, PDPtr, PD),
         PSPtr = PD ^ pd_proc_static,
         MaybeCoveragePoints = PD ^ pd_maybe_coverage_points,
-        
+
         % Gather call site information.
         deep_lookup_proc_statics(Deep, PSPtr, PS),
         StaticCallSitesArray = PS ^ ps_sites,
         DynamicCallSitesArray = PD ^ pd_sites,
         foldl_corresponding(
             add_pd_calls_and_exits_to_map(Deep),
-            to_list(StaticCallSitesArray), to_list(DynamicCallSitesArray), 
+            to_list(StaticCallSitesArray), to_list(DynamicCallSitesArray),
             map.init, CallSitesMap),
-        
+
         % Gather information about the procedure.
         deep_lookup_pd_own(Deep, PDPtr, Own),
 
@@ -1146,18 +1147,18 @@ create_dynamic_procrep_coverage_report(Deep, PDPtr, MaybeReport) :-
     ;
         PDPtr = proc_dynamic_ptr(PDId),
         MaybeReport = error(
-            format("Proc dynamic pointer is invalid %d", [i(PDId)]))
+            string.format("Proc dynamic pointer is invalid %d", [i(PDId)]))
     ).
 
 :- pred maybe_create_procrep_coverage_report(deep::in, proc_static_ptr::in,
-    own_prof_info::in, maybe(array(int))::in, 
+    own_prof_info::in, maybe(array(int))::in,
     map(goal_path, calls_and_exits)::in,
     maybe_error(procrep_coverage_info)::out) is det.
 
 maybe_create_procrep_coverage_report(_, _, _, no, _, error(Error)) :-
     Error = "No coverage information available".
-maybe_create_procrep_coverage_report(Deep, PSPtr, Own, yes(CoveragePointsArray),
-        CallSitesMap, MaybeReport) :-
+maybe_create_procrep_coverage_report(Deep, PSPtr, Own,
+        yes(CoveragePointsArray), CallSitesMap, MaybeReport) :-
     deep_lookup_proc_statics(Deep, PSPtr, PS),
     coverage_point_arrays_to_list(PS ^ ps_coverage_point_infos,
         CoveragePointsArray, CoveragePoints),
@@ -1168,7 +1169,7 @@ maybe_create_procrep_coverage_report(Deep, PSPtr, Own, yes(CoveragePointsArray),
     ;
         MaybeProcRep0 = ok(ProcRep0),
 
-        foldl2(add_coverage_point_to_map, 
+        foldl2(add_coverage_point_to_map,
             CoveragePoints, map.init, SolnsCoveragePointMap,
             map.init, BranchCoveragePointMap),
 
@@ -1194,7 +1195,7 @@ add_ps_calls_and_exits_to_map(Deep, CSSPtr, !.Map) = !:Map :-
     svmap.det_insert(GoalPath, calls_and_exits(calls(Own), exits(Own)), !Map).
 
 :- pred add_pd_calls_and_exits_to_map(deep::in, call_site_static_ptr::in,
-    call_site_array_slot::in, 
+    call_site_array_slot::in,
     map(goal_path, calls_and_exits)::in, map(goal_path, calls_and_exits)::out)
     is det.
 
@@ -1204,14 +1205,14 @@ add_pd_calls_and_exits_to_map(Deep, CSSPtr, Slot, !Map) :-
         csd_get_calls_and_exits(Deep, CSDPtr, Calls, Exits)
     ;
         Slot = slot_multi(_, CSDs),
-        foldl2(csd_get_calls_and_exits_accum(Deep), CSDs, 
+        foldl2(csd_get_calls_and_exits_accum(Deep), CSDs,
             0, Calls, 0, Exits)
     ),
     deep_lookup_call_site_statics(Deep, CSSPtr, CSS),
     goal_path_from_string_det(CSS ^ css_goal_path, GoalPath),
     svmap.det_insert(GoalPath, calls_and_exits(Calls, Exits), !Map).
 
-:- pred csd_get_calls_and_exits(deep::in, call_site_dynamic_ptr::in, 
+:- pred csd_get_calls_and_exits(deep::in, call_site_dynamic_ptr::in,
     int::out, int::out) is det.
 
 csd_get_calls_and_exits(Deep, CSDPtr, Calls, Exits) :-
@@ -1229,7 +1230,7 @@ csd_get_calls_and_exits(Deep, CSDPtr, Calls, Exits) :-
 :- pred csd_get_calls_and_exits_accum(deep::in, call_site_dynamic_ptr::in,
     int::in, int::out, int::in, int::out) is det.
 
-csd_get_calls_and_exits_accum(Deep, CSDPtr, Calls0, Calls0 + NewCalls, 
+csd_get_calls_and_exits_accum(Deep, CSDPtr, Calls0, Calls0 + NewCalls,
         Exits0, Exits0 + NewExits) :-
     csd_get_calls_and_exits(Deep, CSDPtr, NewCalls, NewExits).
 
@@ -1262,7 +1263,7 @@ create_proc_static_dump_report(Deep, PSPtr, MaybeProcStaticDumpInfo) :-
         % Should we dump some other fields?
         PS = proc_static(_ProcId, _DeclModule,
             UnQualRefinedName, QualRefinedName, RawName, FileName, LineNumber,
-            _InInterface, CallSites, CoveragePointInfos, _MaybeCoveragePoints, 
+            _InInterface, CallSites, CoveragePointInfos, _MaybeCoveragePoints,
             _IsZeroed),
         array.max(CallSites, MaxCallSiteIdx),
         NumCallSites = MaxCallSiteIdx + 1,
@@ -1389,12 +1390,13 @@ create_call_site_dynamic_var_use_report(Deep, CSDPtr, MaybeVarUseInfo) :-
                 (
                     MaybeCost = ok(Cost),
                     map_foldl(call_site_dynamic_var_use_arg(Deep, CSDPtr,
-                            RecursionType, Cost, VarTable), 
+                            RecursionType, Cost, VarTable),
                         HeadVars, Uses0, 0, _),
                     list_maybe_error_to_maybe_error_list(Uses0, MaybeUses),
                     (
                         MaybeUses = ok(Uses),
-                        VarUseInfo = call_site_dynamic_var_use_info(Cost, Uses),
+                        VarUseInfo =
+                            call_site_dynamic_var_use_info(Cost, Uses),
                         MaybeVarUseInfo = ok(VarUseInfo)
                     ;
                         MaybeUses = error(Error),
@@ -1414,8 +1416,8 @@ create_call_site_dynamic_var_use_report(Deep, CSDPtr, MaybeVarUseInfo) :-
         )
     ;
         CSDPtr = call_site_dynamic_ptr(CSDNum),
-        MaybeVarUseInfo = error(format(
-            "Invalid call site dynamic %d", [i(CSDNum)]))
+        MaybeVarUseInfo = error(
+            string.format("Invalid call site dynamic %d", [i(CSDNum)]))
     ).
 
 :- pred call_site_dynamic_var_use_arg(deep::in, call_site_dynamic_ptr::in,
@@ -1428,7 +1430,7 @@ call_site_dynamic_var_use_arg(Deep, CSDPtr, RecursionType, Cost, VarTable,
     var_mode_to_var_use_type(Mode, UseType),
     % XXX: Allow user to configure var use options.
     UseOptions = var_use_options(Deep, follow_any_call, UseType),
-    call_site_dynamic_var_use_info(CSDPtr, !.ArgNum, RecursionType, 
+    call_site_dynamic_var_use_info(CSDPtr, !.ArgNum, RecursionType,
         Cost, UseOptions, MaybeUse),
     (
         MaybeUse = ok(Use),
@@ -1461,8 +1463,8 @@ list_maybe_error_to_maybe_error_list([ok(X) | MaybeXs0], MaybeXs) :-
 get_recursive_csd_cost(Deep, CSDPtr, RecursionType, MaybeCost) :-
     (
         RecursionType = rt_not_recursive,
-        MaybeCost = error(
-            "get_recursive_csd_cost called for non-recursive clique")
+        MaybeCost =
+            error("get_recursive_csd_cost called for non-recursive clique")
     ;
         RecursionType = rt_single(_, _, AvgMaxDepth, _, CostFn),
         deep_lookup_csd_own(Deep, CSDPtr, Own),
@@ -1473,8 +1475,7 @@ get_recursive_csd_cost(Deep, CSDPtr, RecursionType, MaybeCost) :-
         ; RecursionType = rt_mutual_recursion(_)
         ; RecursionType = rt_other(_)
         ),
-        MaybeCost = error(
-            "get_recursive_csd_cost: Unhandled recursion type")
+        MaybeCost = error("get_recursive_csd_cost: unhandled recursion type")
     ;
         RecursionType = rt_errors(Errors),
         MaybeCost = error(join_list("\n", Errors))
@@ -1704,10 +1705,10 @@ describe_clique(Deep, CliquePtr, MaybeEntryPDPtr) = CliqueDesc :-
                 list.map(describe_clique_member(Deep), OtherPDPtrs),
             CliqueDesc = clique_desc(CliquePtr, EntryProcDesc, OtherProcDescs)
         ;
-            error("describe_clique", "entry pdptr not a member")
+            unexpected($module, $pred, "entry pdptr not a member")
         )
     ;
-        error("describe_clique", "invalid clique_ptr")
+        unexpected($module, $pred, "invalid clique_ptr")
     ).
 
 :- func describe_clique_member(deep, proc_dynamic_ptr) = proc_desc.
@@ -1716,29 +1717,6 @@ describe_clique_member(Deep, PDPtr) = ProcDesc :-
     deep_lookup_proc_dynamics(Deep, PDPtr, PD),
     ProcDesc = describe_proc(Deep, PD ^ pd_proc_static).
 
-%-----------------------------------------------------------------------------%
-%
-% Code shared across entire module.
-%
-
-:- func this_file = string.
-
-this_file = "create_report.m".
-
-%-----------------------------------------------------------------------------%
-
-:- func error_message(string, string) = string.
-
-error_message(Pred, Message) = Error :-
-    Error = this_file ++ ": " ++ Pred ++ ": " ++ Message.
-
-%-----------------------------------------------------------------------------%
-
-:- pred error(string::in, string::in) is erroneous.
-
-error(Pred, Message) :-
-    throw(software_error(error_message(Pred, Message))).
-
 %-----------------------------------------------------------------------------%
 :- end_module create_report.
 %-----------------------------------------------------------------------------%
diff --git a/deep_profiler/dense_bitset.m b/deep_profiler/dense_bitset.m
index 771b9ed70..9efad8a86 100644
--- a/deep_profiler/dense_bitset.m
+++ b/deep_profiler/dense_bitset.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001, 2003, 2005-2006 The University of Melbourne.
+% Copyright (C) 2001, 2003, 2005-2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -87,7 +87,7 @@ insert(A0, I) = A :-
         Word = Word0 \/ bit(I),
         set(A0, word(I), Word, A)
     ;
-        error("insert: cannot use indexes < 0")
+        unexpected($module, $pred, "cannot use indexes < 0")
     ).
 
 delete(A0, I) = A :-
@@ -99,7 +99,7 @@ delete(A0, I) = A :-
         Word = Word0 /\ \ bit(I),
         set(A0, word(I), Word, A)
     ;
-        error("delete: cannot use indexes < 0")
+        unexpected($module, $pred, "cannot use indexes < 0")
     ).
 
 union(A, B) = C :-
diff --git a/deep_profiler/display.m b/deep_profiler/display.m
index 33721ff6c..fec217ab6 100644
--- a/deep_profiler/display.m
+++ b/deep_profiler/display.m
@@ -212,7 +212,7 @@
 
 %-----------------------------------------------------------------------------%
 %
-% List specific structures
+% List specific structures.
 %
 
 :- type list_class
@@ -223,7 +223,7 @@
 
 %-----------------------------------------------------------------------------%
 %
-% Link specific structures
+% Link specific structures.
 %
 
 :- type deep_link
diff --git a/deep_profiler/display_report.m b/deep_profiler/display_report.m
index eb8145ce3..1bad84d1a 100644
--- a/deep_profiler/display_report.m
+++ b/deep_profiler/display_report.m
@@ -22,7 +22,7 @@
 :- import_module report.
 
 % XXX: This include should be removed or replaced.  Some data structures
-% such as preferences are currently defined in query, they should be moved
+% such as preferences are currently defined in query; they should be moved
 % into a different module so that this module doesn't need to include
 % the whole of query.
 :- import_module query.
@@ -165,7 +165,8 @@ report_to_display(Deep, Prefs, Report) = Display :-
         Report = report_proc_callers(MaybeProcCallersReport),
         (
             MaybeProcCallersReport = ok(ProcCallersReport),
-            display_report_proc_callers(Deep, Prefs, ProcCallersReport, Display)
+            display_report_proc_callers(Deep, Prefs, ProcCallersReport,
+                Display)
         ;
             MaybeProcCallersReport = error(Msg),
             Display = display(no, [display_heading(Msg)])
@@ -222,7 +223,8 @@ report_to_display(Deep, Prefs, Report) = Display :-
         Report = report_call_site_dynamic_var_use(MaybeVarUseInfo),
         (
             MaybeVarUseInfo = ok(VarUseInfo),
-            display_report_call_site_dynamic_var_use(Prefs, VarUseInfo, Display)
+            display_report_call_site_dynamic_var_use(Prefs, VarUseInfo,
+                Display)
         ;
             MaybeVarUseInfo = error(Msg),
             Display = display(no, [display_heading(Msg)])
@@ -263,7 +265,7 @@ display_report_menu(Deep, Prefs, MenuReport, Display) :-
 
     (
         ShouldDisplayTimes = yes,
-    
+
         Top100SelfCmd = deep_cmd_top_procs(rank_range(1, 100),
             cost_time, self, overall),
         Top100SelfAndDescCmd = deep_cmd_top_procs(rank_range(1, 100),
@@ -277,7 +279,7 @@ display_report_menu(Deep, Prefs, MenuReport, Display) :-
         ]
     ;
         ShouldDisplayTimes = no,
-        LinksTopProcsByLimitTime = [] 
+        LinksTopProcsByLimitTime = []
     ),
 
     TopLimitCallSeqsSelf = deep_cmd_top_procs(rank_range(1, 100),
@@ -352,7 +354,7 @@ display_report_menu(Deep, Prefs, MenuReport, Display) :-
         link_base(WordsAbove2Megawords, yes(Prefs),
             "Procedures above 2M words threshold: words, self+descendants.")
     ],
-    
+
     LinkCmds = LinksExploration ++
         LinksTopProcsByLimitTime ++ LinksTopProcsByLimit ++
         LinksTopProcsByPercentTime ++ LinksTopProcsByPercent,
@@ -365,15 +367,16 @@ display_report_menu(Deep, Prefs, MenuReport, Display) :-
     % Produce the developer-only options list.
     %
     RecursionTypeFrequenciesCmd = deep_cmd_recursion_types_frequency,
-    
+
     LinksDeveloperCmds = [
         link_base(RecursionTypeFrequenciesCmd, yes(Prefs),
             "Frequencies of different types of recursion used in the program.")
     ],
     list.map(make_link, LinksDeveloperCmds, DeveloperLinksList),
-    DeveloperLinks = display_developer(display_list(list_class_vertical_bullets,
-        yes("Options that are only useful to Mercury developers"), 
-        DeveloperLinksList)),
+    DeveloperLinks = display_developer(
+        display_list(list_class_vertical_bullets,
+            yes("Options that are only useful to Mercury developers"),
+            DeveloperLinksList)),
 
     % Display the table section of the report.
     ProfilingStatistics =
@@ -639,7 +642,7 @@ clique_call_site_to_rows(MaybeCurModuleName, ModuleQual, Prefs,
             Rows = [Row]
         ;
             CalleePerfs = [_, _ | _],
-            error("clique_call_site_to_rows: more than one callee at normal")
+            unexpected($module, $pred, "more than one callee at normal")
         )
     ;
         (
@@ -705,7 +708,7 @@ clique_call_site_callee_to_row(MaybeCurModuleName, ModuleQual, Prefs,
     clique_recursion_report::in, display::out) is det.
 
 display_report_clique_recursion(Prefs, CliqueRecursionReport, Display) :-
-    CliqueRecursionReport = clique_recursion_report(CliquePtr, RecursionType, 
+    CliqueRecursionReport = clique_recursion_report(CliquePtr, RecursionType,
         _NumProcs),
     Cmd = deep_cmd_clique_recursive_costs(CliquePtr),
     CliquePtr = clique_ptr(CliqueNum),
@@ -714,14 +717,14 @@ display_report_clique_recursion(Prefs, CliqueRecursionReport, Display) :-
 
     display_recursion_type(RecursionType, DisplayRecursionType),
 
-    CliqueReportsControls = clique_reports_controls(Prefs, CliquePtr, Cmd), 
-    
+    CliqueReportsControls = clique_reports_controls(Prefs, CliquePtr, Cmd),
+
     MenuRestartQuitControls = cmds_menu_restart_quit(yes(Prefs)),
     Display = display(yes(Title), DisplayRecursionType ++
         [display_paragraph_break, CliqueReportsControls,
          display_paragraph_break, MenuRestartQuitControls]).
 
-:- pred display_recursion_type(recursion_type::in, list(display_item)::out) 
+:- pred display_recursion_type(recursion_type::in, list(display_item)::out)
     is det.
 
 display_recursion_type(RecursionType, Items) :-
@@ -731,7 +734,7 @@ display_recursion_type(RecursionType, Items) :-
             Text = "Clique is non-recursive"
         ;
             RecursionType = rt_mutual_recursion(NumProcs),
-            Text = format("Mutual recursion between %d procedures", 
+            Text = format("Mutual recursion between %d procedures",
                 [i(NumProcs)])
         ),
         Items = [display_text(Text)]
@@ -742,21 +745,21 @@ display_recursion_type(RecursionType, Items) :-
             yes("Unknown, error(s) occured"), ErrorItems)]
     ;
         (
-            RecursionType = rt_single(BaseLevel, RecLevel, AvgDepth, 
+            RecursionType = rt_single(BaseLevel, RecLevel, AvgDepth,
                 AvgRecCost, AnyRecCost),
             RowData = [
-                {"Base case", BaseLevel}, 
+                {"Base case", BaseLevel},
                 {"Recursive case", RecLevel}],
             Text = "Single-recursion:",
 
             MaxDepthI = round_to_int(AvgDepth),
-            ExtraTableRows0 = 
-                [{"Average recursion depth:", AvgDepth}, 
-                 {"Average recursive call cost (excluding the call it's self):",
+            ExtraTableRows0 =
+                [{"Average recursion depth:", AvgDepth},
+                 {"Average recursive call cost (excluding the call itself):",
                     AvgRecCost}] ++
                 map(
                     (func(Level) =
-                        {format("Cost at depth %d:", [i(Level)]), 
+                        {string.format("Cost at depth %d:", [i(Level)]),
                             AnyRecCost(Level)}),
                     [0, 1, 2, round_to_int(AvgDepth / 2.0),
                      MaxDepthI - 2, MaxDepthI - 1, MaxDepthI]),
@@ -771,42 +774,43 @@ display_recursion_type(RecursionType, Items) :-
             Text = "Double-recursion (Probably Divide and Conquer):",
 
             ExtraTableRows = []
-        ; 
+        ;
             RecursionType = rt_other(Levels),
             RowData = map((func(Level) = {Label, Level} :-
-                    Label = format("Case for %d recursive calls", 
+                    Label = string.format("Case for %d recursive calls",
                         [i(Level ^ rlr_level)])
-                ), Levels), 
+                ), Levels),
             Text = "Unknown recursion type:",
 
             ExtraTableRows = []
         ),
         Rows = map(make_recursion_table_row, RowData),
-            
-        ExtraTable = display_table(table(table_class_do_not_box, 2, no, 
+
+        ExtraTable = display_table(table(table_class_do_not_box, 2, no,
             ExtraTableRows)),
 
         Header = table_header(map(
-            (func({Name, Class}) = 
+            (func({Name, Class}) =
                 table_header_group(table_header_group_single(td_s(Name)),
                     Class, column_do_not_colour)
-            ), 
+            ),
             [{"Recursion type", table_column_class_field_name},
              {"Exec count", table_column_class_number},
-             {"Non recursive calls per-call cost", table_column_class_callseqs},
-             {"Recursive calls per-call cost (ex children)", 
+             {"Non recursive calls per-call cost",
+                table_column_class_callseqs},
+             {"Recursive calls per-call cost (ex children)",
                 table_column_class_callseqs}])),
-        Table = display_table(table(table_class_box_if_pref, 4, yes(Header), 
+        Table = display_table(table(table_class_box_if_pref, 4, yes(Header),
             Rows)),
         Description = display_text(Text),
-        Items = [Description, 
+        Items = [Description,
             display_paragraph_break, Table,
             display_paragraph_break, ExtraTable]
     ).
 
 :- func make_recursion_table_row({string, recursion_level_report}) = table_row.
 
-make_recursion_table_row({Label, Report}) = 
+make_recursion_table_row({Label, Report}) =
     table_row([table_cell(td_s(Label)),
         table_cell(td_i(Report ^ rlr_calls)),
         table_cell(td_f(Report ^ rlr_non_rec_calls_cost)),
@@ -822,8 +826,9 @@ display_report_recursion_types_frequency(Prefs, Report, Display) :-
     Title = "Frequencies of recognized recursion types",
 
     % Build the table.
-    RecursionTypeLink = deep_link(Cmd, yes(Prefs ^ pref_criteria := by_context),
-        attr_str([], "Recursion Type"), link_class_link), 
+    RecursionTypeLink = deep_link(Cmd,
+        yes(Prefs ^ pref_criteria := by_context),
+        attr_str([], "Recursion Type"), link_class_link),
     RecursionTypeHeaderGroup = make_single_table_header_group(
         td_l(RecursionTypeLink), table_column_class_no_class,
         column_do_not_colour),
@@ -833,7 +838,7 @@ display_report_recursion_types_frequency(Prefs, Report, Display) :-
     PercentageHeaderGroup = make_single_table_header_group(
         td_s("Percentage"), table_column_class_no_class,
         column_do_not_colour),
-    perf_table_header(total_columns_meaningful, Prefs, 
+    perf_table_header(total_columns_meaningful, Prefs,
         override_order_criteria_header_data(Cmd), PerfHeaderGroups),
     AllHeaderGroups = [RecursionTypeHeaderGroup, FreqHeaderGroup,
         PercentageHeaderGroup] ++ PerfHeaderGroups,
@@ -841,7 +846,8 @@ display_report_recursion_types_frequency(Prefs, Report, Display) :-
 
     Histogram1 = map.to_assoc_list(Histogram0),
     sort_recursion_types_by_preferences(Prefs, Histogram1, Histogram),
-    map(display_report_rec_type_freq_rows(Prefs, NumColumns), Histogram, Rowss),
+    list.map(display_report_rec_type_freq_rows(Prefs, NumColumns),
+        Histogram, Rowss),
     list.condense(Rowss, Rows),
     RecursionTypesTable = display_table(table(table_class_box_if_pref,
         NumColumns, yes(Header), Rows)),
@@ -850,7 +856,7 @@ display_report_recursion_types_frequency(Prefs, Report, Display) :-
     FieldControls = field_controls(Prefs, Cmd),
     FormatControls = format_controls(Prefs, Cmd),
     MenuRestartQuitControls = cmds_menu_restart_quit(yes(Prefs)),
-    
+
     Display = display(yes(Title), [RecursionTypesTable,
         display_paragraph_break, ModuleQualControls,
         display_paragraph_break, FieldControls,
@@ -871,7 +877,8 @@ sort_recursion_types_by_preferences(Prefs, !RecursionTypes) :-
         list.sort(compare_recursion_type_row_by_rec_type, !RecursionTypes)
     ;
         OrderCriteria = by_cost(CostKind, InclDesc, Scope),
-        list.sort(compare_rec_type_row_datas_by_cost(CostKind, InclDesc, Scope),
+        list.sort(
+            compare_rec_type_row_datas_by_cost(CostKind, InclDesc, Scope),
             !RecursionTypes),
         % We want the most expensive rows to appear first.
         list.reverse(!RecursionTypes)
@@ -879,7 +886,7 @@ sort_recursion_types_by_preferences(Prefs, !RecursionTypes) :-
 
 :- pred sort_recursion_type_procs_by_preferences(preferences::in,
     list(recursion_type_proc_freq_data)::in,
-    list(recursion_type_proc_freq_data)::out) is det. 
+    list(recursion_type_proc_freq_data)::out) is det.
 
 sort_recursion_type_procs_by_preferences(Prefs, !RecursionTypeProcs) :-
     OrderCriteria = Prefs ^ pref_criteria,
@@ -907,8 +914,6 @@ sort_recursion_type_procs_by_preferences(Prefs, !RecursionTypeProcs) :-
 compare_recursion_type_row_by_rec_type(RTA - _, RTB - _, Result) :-
     compare(Result, RTA, RTB).
 
-    % This is reversed so that entries with larger frequencies are listed first.
-    %
 :- pred compare_recursion_proc_row_by_frequency_rev(
     recursion_type_proc_freq_data::in, recursion_type_proc_freq_data::in,
     comparison_result::out) is det.
@@ -916,6 +921,7 @@ compare_recursion_type_row_by_rec_type(RTA - _, RTB - _, Result) :-
 compare_recursion_proc_row_by_frequency_rev(
         recursion_type_proc_freq_data(FreqA, _, _),
         recursion_type_proc_freq_data(FreqB, _, _), Result) :-
+    % The reverse is so that entries with larger frequencies are listed first.
     compare(Result, FreqB, FreqA).
 
 :- pred compare_rec_type_row_datas_by_cost(cost_kind::in,
@@ -924,14 +930,14 @@ compare_recursion_proc_row_by_frequency_rev(
     pair(T, recursion_type_freq_data)::in,
     comparison_result::out) is det.
 
-compare_rec_type_row_datas_by_cost(CostKind, IncDesc, Scope, _ - DataA, 
-        _ - DataB, Result) :- 
+compare_rec_type_row_datas_by_cost(CostKind, IncDesc, Scope, _ - DataA,
+        _ - DataB, Result) :-
     MaybePerfA = DataA ^ rtfd_maybe_summary,
     MaybePerfB = DataB ^ rtfd_maybe_summary,
     (
         MaybePerfA = yes(PerfA),
         MaybePerfB = yes(PerfB),
-        compare_perf_row_datas_by_cost(CostKind, IncDesc, Scope, 
+        compare_perf_row_datas_by_cost(CostKind, IncDesc, Scope,
             PerfA, PerfB, Result)
     ;
         MaybePerfA = yes(_),
@@ -952,18 +958,18 @@ compare_rec_type_row_datas_by_cost(CostKind, IncDesc, Scope, _ - DataA,
     recursion_type_proc_freq_data::in, recursion_type_proc_freq_data::in,
     comparison_result::out) is det.
 
-compare_rec_proc_row_datas_by_cost(CostKind, InclDesc, Scope, 
+compare_rec_proc_row_datas_by_cost(CostKind, InclDesc, Scope,
         recursion_type_proc_freq_data(_, _, PerfA),
         recursion_type_proc_freq_data(_, _, PerfB), Result) :-
     compare_perf_row_datas_by_cost(CostKind, InclDesc, Scope, PerfA, PerfB,
         Result).
 
 :- pred display_report_rec_type_freq_rows(preferences::in, int::in,
-    pair(recursion_type_simple, recursion_type_freq_data)::in, 
+    pair(recursion_type_simple, recursion_type_freq_data)::in,
     list(table_row)::out) is det.
 
 display_report_rec_type_freq_rows(Prefs, NumColumns, Type - FreqData, Rows) :-
-    FreqData = recursion_type_freq_data(Frequency, Percent, MaybeSummary, 
+    FreqData = recursion_type_freq_data(Frequency, Percent, MaybeSummary,
         ProcsMap),
 
     % Make the header row.
@@ -974,7 +980,7 @@ display_report_rec_type_freq_rows(Prefs, NumColumns, Type - FreqData, Rows) :-
     (
         MaybeSummary = yes(Summary),
         perf_table_row(total_columns_meaningful, Prefs ^ pref_fields, Summary,
-            SummaryCells)  
+            SummaryCells)
     ;
         MaybeSummary = no,
         duplicate(NumColumns - 3, table_empty_cell, SummaryCells)
@@ -988,18 +994,18 @@ display_report_rec_type_freq_rows(Prefs, NumColumns, Type - FreqData, Rows) :-
     take_upto(Prefs ^ pref_proc_statics_per_rec_type, Procs1, Procs),
     map(display_report_rec_type_proc_rows(Prefs), Procs, ProcRows),
 
-    Rows = [HeaderRow | [Row | ProcRows ++ 
+    Rows = [HeaderRow | [Row | ProcRows ++
         [table_separator_row]]].
 
 :- pred display_report_rec_type_proc_rows(preferences::in,
     recursion_type_proc_freq_data::in, table_row::out) is det.
 
-display_report_rec_type_proc_rows(Prefs, 
+display_report_rec_type_proc_rows(Prefs,
         recursion_type_proc_freq_data(Freq, Percent, Summary), Row) :-
     perf_table_row(total_columns_meaningful, Prefs ^ pref_fields, Summary,
         SummaryCells),
     ProcDesc = Summary ^ perf_row_subject,
-    ProcCell = proc_desc_to_proc_name_cell(no, Prefs ^ pref_module_qual, Prefs, 
+    ProcCell = proc_desc_to_proc_name_cell(no, Prefs ^ pref_module_qual, Prefs,
         ProcDesc),
     Row = table_row([ProcCell, table_cell(td_i(Freq)),
         table_cell(td_p(Percent))] ++ SummaryCells).
@@ -1009,14 +1015,16 @@ display_report_rec_type_proc_rows(Prefs,
 
 display_report_recursion_type_simple(rts_not_recursive, "Not recursive").
 display_report_recursion_type_simple(rts_single, "Single-recursion").
-display_report_recursion_type_simple(rts_divide_and_conquer, "Divide and conquer").
+display_report_recursion_type_simple(rts_divide_and_conquer,
+        "Divide and conquer").
 display_report_recursion_type_simple(rts_mutual_recursion(NumProcs), String) :-
     format("Mutual recursion between %d procs", [i(NumProcs)], String).
 display_report_recursion_type_simple(rts_other(Levels), String) :-
     LevelsStr = join_list(", ", map(string, set.to_sorted_list(Levels))),
     format("Other recursion with levels: %s", [s(LevelsStr)], String).
-display_report_recursion_type_simple(rts_total_error_instances, "Total errors").
-display_report_recursion_type_simple(rts_error(Error), "Error: " ++ Error). 
+display_report_recursion_type_simple(rts_total_error_instances,
+        "Total errors").
+display_report_recursion_type_simple(rts_error(Error), "Error: " ++ Error).
 
 %-----------------------------------------------------------------------------%
 %
@@ -2027,7 +2035,7 @@ display_report_procrep_coverage_info(Prefs, ProcrepCoverageReport, Display) :-
     % Print the coverage information for a goal, this is used by
     % print_proc_to_strings.
     %
-:- pred coverage_to_cord_string(var_table::in, coverage_info::in, 
+:- pred coverage_to_cord_string(var_table::in, coverage_info::in,
     cord(cord(string))::out) is det.
 
 coverage_to_cord_string(_, Coverage, singleton(singleton(String))) :-
@@ -2127,7 +2135,7 @@ display_report_proc_dynamic_dump(_Deep, Prefs, ProcDynamicDumpInfo, Display) :-
         list.map(format_coverage_point_row, CoveragePoints,
             CoveragePointsRows),
         CoveragePointsTableHeader = table_header([
-            table_header_group(table_header_group_single(td_s("Goal Path")), 
+            table_header_group(table_header_group_single(td_s("Goal Path")),
                 table_column_class_no_class, column_do_not_colour),
             table_header_group(table_header_group_single(td_s("Type")),
                 table_column_class_no_class, column_do_not_colour),
@@ -2137,7 +2145,8 @@ display_report_proc_dynamic_dump(_Deep, Prefs, ProcDynamicDumpInfo, Display) :-
             yes(CoveragePointsTableHeader), CoveragePointsRows),
         CoveragePointsTableItem = display_table(CoveragePointsTable),
 
-        CoveragePointsItems = [CoveragePointsTitleItem, CoveragePointsTableItem]
+        CoveragePointsItems =
+            [CoveragePointsTitleItem, CoveragePointsTableItem]
     ;
         MaybeCoveragePoints = no,
         CoveragePointsItems = []
@@ -2146,7 +2155,7 @@ display_report_proc_dynamic_dump(_Deep, Prefs, ProcDynamicDumpInfo, Display) :-
     make_link(link_base(deep_cmd_dynamic_procrep_coverage(PDPtr), yes(Prefs),
             "Dynamic coverage annotated procedure representation"),
         CoverageAnnotatedProcrepItem),
-    RelatedReportsList = display_list(list_class_horizontal_except_title, 
+    RelatedReportsList = display_list(list_class_horizontal_except_title,
         yes("Related reports:"), [CoverageAnnotatedProcrepItem]),
 
     Display = display(yes(Title),
@@ -2364,7 +2373,7 @@ display_report_call_site_dynamic_var_use(_Prefs, CSDVarUseInfo, Display) :-
                 {"Name", table_column_class_no_class},
                 {"Type", table_column_class_no_class},
                 {"Percent into proc", table_column_class_no_class},
-                {"Time into proc (Callseqs)", table_column_class_callseqs}])), 
+                {"Time into proc (Callseqs)", table_column_class_callseqs}])),
     Table = table(table_class_box_if_pref, 5, yes(Header), VarUseRows),
 
     Title = "Dump of var use info",
@@ -2376,7 +2385,7 @@ display_report_call_site_dynamic_var_use(_Prefs, CSDVarUseInfo, Display) :-
 format_var_uses([], _, []).
 format_var_uses([VarUse | VarUses], RowNum, [Row | Rows]) :-
     HeaderCell = table_cell(td_s(format("Argument: %i", [i(RowNum)]))),
-    VarUse = var_use_and_name(Name, 
+    VarUse = var_use_and_name(Name,
         var_use_info(CostUntilUse, ProcCost, UseType)),
     NameCell = table_cell(td_s(Name)),
     (
@@ -2438,6 +2447,7 @@ dummy_order_criteria_header_data(_, _, Label) = td_s(Label).
 %
 % Each pair of predicates should follow the exact same logic when selecting
 % what columns to display, and in what order.
+%
 
 :- type total_columns_meaning
     --->    total_columns_meaningful
@@ -2600,7 +2610,7 @@ perf_table_row_time(TotalsMeaningful, Fields, RowData, TimeCells) :-
                 MaybeTotal = yes(Total)
             ;
                 MaybeTotal = no,
-                error("perf_table_row_time: no total")
+                unexpected($module, $pred, "no total")
             ),
             TotalTicks =            Total ^ perf_row_ticks,
             TotalTime =             Total ^ perf_row_time,
@@ -2799,7 +2809,7 @@ perf_table_row_callseqs(TotalsMeaningful, Fields, RowData, CallSeqsCells) :-
                 MaybeTotal = yes(Total)
             ;
                 MaybeTotal = no,
-                error("perf_table_row_callseqs: no total")
+                unexpected($module, $pred, "no total")
             ),
             TotalCallSeqs =             Total ^ perf_row_callseqs,
             TotalCallSeqsPercent =      Total ^ perf_row_callseqs_percent,
@@ -2926,7 +2936,7 @@ perf_table_row_allocs(TotalsMeaningful, Fields, RowData, AllocCells) :-
                 MaybeTotal = yes(Total)
             ;
                 MaybeTotal = no,
-                error("perf_table_row_allocs: no total")
+                unexpected($module, $pred, "no total")
             ),
             TotalAllocs =               Total ^ perf_row_allocs,
             TotalAllocsPercent =        Total ^ perf_row_allocs_percent,
@@ -3053,7 +3063,7 @@ perf_table_row_memory(TotalsMeaningful, Fields, RowData, MemoryCells) :-
                 MaybeTotal = yes(Total)
             ;
                 MaybeTotal = no,
-                error("perf_table_row_memory: no total")
+                unexpected($module, $pred, "no total")
             ),
             TotalMem =              Total ^ perf_row_mem,
             TotalMemPerCall =       Total ^ perf_row_mem_percall,
@@ -3800,7 +3810,8 @@ set_box_tables(Box, !Prefs) :-
 % Controls for related procedure and clique reports.
 %
 
-:- func proc_reports_controls(preferences, proc_static_ptr, cmd) = display_item.
+:- func proc_reports_controls(preferences, proc_static_ptr, cmd)
+    = display_item.
 
 proc_reports_controls(Prefs, Proc, NotCmd) = ControlsItem :-
     solutions((pred(Control::out) is nondet :-
@@ -3825,10 +3836,11 @@ proc_reports_controls(Prefs, Proc, NotCmd) = ControlsItem :-
     ControlsItem = display_list(list_class_vertical_no_bullets,
         yes("Related procedure reports:"), ProcReportControls).
 
-:- func clique_reports_controls(preferences, clique_ptr, cmd) = display_item. 
+:- func clique_reports_controls(preferences, clique_ptr, cmd) = display_item.
 
 clique_reports_controls(Perfs, CliquePtr, NotCmd) = ControlsItem :-
-    solutions((pred(Control::out) is nondet :-
+    MakeControls =
+        ( pred(Control::out) is nondet :-
             (
                 Cmd = deep_cmd_clique(CliquePtr),
                 Label = "Clique",
@@ -3844,7 +3856,8 @@ clique_reports_controls(Perfs, CliquePtr, NotCmd) = ControlsItem :-
             ),
             Cmd \= NotCmd,
             make_control(yes(Perfs), Cmd, Label, Developer, Control)
-        ), CliqueReportControls),
+        ),
+    solutions(MakeControls, CliqueReportControls),
     ControlsItem = display_list(list_class_vertical_no_bullets,
         yes("Related clique reports:"), CliqueReportControls).
 
@@ -4167,17 +4180,17 @@ general_options_controls(Cmd, Prefs) = ControlsItem :-
     (
         DeveloperMode = developer_options_visible,
         DeveloperText = "Disable developer options",
-        DeveloperPrefs = 
+        DeveloperPrefs =
             Prefs ^ pref_developer_mode := developer_options_invisible
     ;
         DeveloperMode = developer_options_invisible,
         DeveloperText = "Enable developer options",
-        DeveloperPrefs = 
+        DeveloperPrefs =
             Prefs ^ pref_developer_mode := developer_options_visible
     ),
     DeveloperControl = display_link(deep_link(Cmd, yes(DeveloperPrefs),
         attr_str([], DeveloperText), link_class_control)),
-    List = [DeveloperControl], 
+    List = [DeveloperControl],
     ControlsItem = display_list(list_class_horizontal_except_title,
         yes("General options:"), List).
 
@@ -4883,8 +4896,8 @@ compare_module_name_rows_by_name(ModuleRowDataA, ModuleRowDataB, Result) :-
 %
 
 :- pred sort_clique_rows_by_preferences(preferences::in,
-    list(perf_row_data(clique_desc))::in, list(perf_row_data(clique_desc))::out)
-    is det.
+    list(perf_row_data(clique_desc))::in,
+    list(perf_row_data(clique_desc))::out) is det.
 
 sort_clique_rows_by_preferences(Prefs, !CliqueRowDatas) :-
     OrderCriteria = Prefs ^ pref_criteria,
@@ -5107,7 +5120,7 @@ compare_perf_row_datas_by_time(InclDesc, Scope, PerfA, PerfB, Result) :-
                 compare(Result, TimeA, TimeB)
             )
         ;
-            error("compare_perf_row_datas_by_cost: self_and_desc")
+            unexpected($module, $pred, "self_and_desc")
         )
     ).
 
@@ -5151,7 +5164,7 @@ compare_perf_row_datas_by_callseqs(InclDesc, Scope, PerfA, PerfB, Result) :-
                 compare(Result, CallSeqsA, CallSeqsB)
             )
         ;
-            error("compare_perf_row_datas_by_cost: self_and_desc")
+            unexpected($module, $pred, "self_and_desc")
         )
     ).
 
@@ -5195,7 +5208,7 @@ compare_perf_row_datas_by_allocs(InclDesc, Scope, PerfA, PerfB, Result) :-
                 compare(Result, AllocsA, AllocsB)
             )
         ;
-            error("compare_perf_row_datas_by_cost: self_and_desc")
+            unexpected($module, $pred, "self_and_desc")
         )
     ).
 
@@ -5239,7 +5252,7 @@ compare_perf_row_datas_by_words(InclDesc, Scope, PerfA, PerfB, Result) :-
                 compare_memory(MemoryA, MemoryB, Result)
             )
         ;
-            error("compare_perf_row_datas_by_cost: self_and_desc")
+            unexpected($module, $pred, "self_and_desc")
         )
     ).
 
diff --git a/deep_profiler/dump.m b/deep_profiler/dump.m
index cdb312350..d28dfecf9 100644
--- a/deep_profiler/dump.m
+++ b/deep_profiler/dump.m
@@ -316,7 +316,7 @@ dump_init_profile_stats(Stats, !IO) :-
         Compression = no_compression,
         io.write_string("none\n", !IO)
     ),
-    io.format("\tcoverage_data_type = %s\n", [s(string(CoverageDataType))], 
+    io.format("\tcoverage_data_type = %s\n", [s(string(CoverageDataType))],
         !IO),
     io.nl(!IO).
 
@@ -540,7 +540,7 @@ dump_proc_static(Restriction, Index, ProcStatic, !IO) :-
     ->
         ProcStatic = proc_static(Id, DeclModule,
             _UnQualRefinedId, QualRefinedId, RawId, FileName, LineNumber,
-            InInterface, Sites, CoveragePointInfos, MaybeCoveragePoints, 
+            InInterface, Sites, CoveragePointInfos, MaybeCoveragePoints,
             IsZeroed),
         IdStr = dump_proc_id(Id),
         io.format("ps%d:\n", [i(Index)], !IO),
@@ -586,7 +586,7 @@ dump_proc_static(Restriction, Index, ProcStatic, !IO) :-
             MaybeCoveragePoints = no,
             io.write_string("\tCoverage counts not present in proc static\n",
                 !IO),
-            array_foldl_from_0(dump_coverage_point_info, CoveragePointInfos, 
+            array_foldl_from_0(dump_coverage_point_info, CoveragePointInfos,
                 !IO)
         ),
         io.nl(!IO)
@@ -611,7 +611,7 @@ dump_coverage_point(CoveragePoint, !Num, !IO) :-
     io.format("\t%s: %d\n", [s(CPInfoStr), i(Count)], !IO),
     !:Num = !.Num + 1.
 
-:- pred dump_coverage_point_info(int::in, coverage_point_info::in, 
+:- pred dump_coverage_point_info(int::in, coverage_point_info::in,
     io::di, io::uo) is det.
 
 dump_coverage_point_info(Num, CoveragePointInfo, !IO) :-
@@ -622,7 +622,7 @@ dump_coverage_point_info(Num, CoveragePointInfo, !IO) :-
 
 format_cp_info(Num, coverage_point_info(Path, CPType), String) :-
     goal_path_to_string(Path) = PathString,
-    format("coverage_point[%d]: %s, %s", 
+    format("coverage_point[%d]: %s, %s",
         [i(Num), s(string(CPType)), s(PathString)], String).
 
 %----------------------------------------------------------------------------%
@@ -766,7 +766,8 @@ dump_deep_rev_links(Deep, !IO) :-
     io.nl(!IO),
 
     CallSiteStaticMap = Deep ^ call_site_static_map,
-    io.write_string("SECTION MAP FROM CALL SITE DYNAMICS TO STATICS:\n\n", !IO),
+    io.write_string("SECTION MAP FROM CALL SITE DYNAMICS TO STATICS:\n\n",
+        !IO),
     array_foldl_from_1(dump_call_site_dynamic_to_static, CallSiteStaticMap,
         !IO),
     io.nl(!IO),
diff --git a/deep_profiler/html_format.m b/deep_profiler/html_format.m
index 22b64f4bc..78d96d579 100644
--- a/deep_profiler/html_format.m
+++ b/deep_profiler/html_format.m
@@ -429,7 +429,7 @@ update_style_control_map(ColumnClassStr, !HeaderGroupNumber,
         Colour = "White"
     ),
     ( set.member(ColumnClassStr, !.ColouredClassStrs) ->
-        error("update_style_control_map: repeated table_column_class")
+        unexpected($module, $pred, "repeated table_column_class")
     ;
         set.insert(!.ColouredClassStrs, ColumnClassStr, !:ColouredClassStrs)
     ),
@@ -498,7 +498,7 @@ table_cell_to_html(FormatInfo, MaybeClassMap, !StyleControlMap, !ColumnNum,
                 Msg = string.format(
                     "Class map had no class for col %d, check table structure",
                     [i(!.ColumnNum)]),
-                error(Msg)
+                unexpected($module, $pred, Msg)
             )
         ;
             MaybeClassMap = no,
@@ -725,7 +725,7 @@ default_style_control_map =
 
     % Transform a list of items into HTML.
     %
-:- pred list_to_html(format_info::in, 
+:- pred list_to_html(format_info::in,
     style_control_map::in, style_control_map::out,
     list_class::in, maybe(string)::in, list(display_item)::in, html::out)
     is det.
@@ -842,7 +842,7 @@ pseudo_link_to_html(_FormatInfo, PseudoLink) = HTML :-
 :- func init_format_info(deep, preferences) = format_info.
 
 init_format_info(Deep, Prefs) = FormatInfo :-
-    FormatInfo = format_info(Prefs ^ pref_colour, Prefs ^ pref_box, 
+    FormatInfo = format_info(Prefs ^ pref_colour, Prefs ^ pref_box,
         Prefs ^ pref_developer_mode,
         Deep ^ server_name_port, Deep ^ script_name, Deep ^ data_file_name).
 
diff --git a/deep_profiler/io_combinator.m b/deep_profiler/io_combinator.m
index 54c5e6943..b5a7c6eec 100644
--- a/deep_profiler/io_combinator.m
+++ b/deep_profiler/io_combinator.m
@@ -693,7 +693,7 @@
     pred(maybe_error(T11), io, io),
     pred(maybe_error(T12), io, io),
     pred(maybe_error(T13), io, io),
-    pred(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, 
+    pred(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
         maybe_error(T)),
     maybe_error(T), io, io).
 :- mode io_combinator.maybe_error_sequence_13(
diff --git a/deep_profiler/mdprof_cgi.m b/deep_profiler/mdprof_cgi.m
index 48782e88d..2083dba59 100644
--- a/deep_profiler/mdprof_cgi.m
+++ b/deep_profiler/mdprof_cgi.m
@@ -176,7 +176,7 @@ decode_input_lines(Decode, DecodeCmd, DecodePrefs, !IO) :-
                 io.nl(!IO)
             ;
                 MaybeQuery = no,
-                io.write_string("invalid query string: " ++ 
+                io.write_string("invalid query string: " ++
                     "cannot split into components\n", !IO)
             )
         ),
@@ -496,7 +496,7 @@ handle_query_from_new_server(Cmd, PrefInd, FileName, ToServerPipe,
     % of the critical region.
     %
 :- pred start_server(option_table::in, string::in, string::in,
-    maybe(io.output_stream)::in, string::in, string::in, 
+    maybe(io.output_stream)::in, string::in, string::in,
     deep::in, io::di, io::uo) is cc_multi.
 
 start_server(Options, ToServerPipe, FromServerPipe, MaybeStartupStream,
@@ -582,7 +582,7 @@ start_server(Options, ToServerPipe, FromServerPipe, MaybeStartupStream,
     ).
 
 :- pred server_loop(string::in, string::in, int::in,
-    maybe(io.output_stream)::in, bool::in, bool::in, int::in, 
+    maybe(io.output_stream)::in, bool::in, bool::in, int::in,
     deep::in, io::di, io::uo) is cc_multi.
 
 server_loop(ToServerPipe, FromServerPipe, TimeOut0, MaybeStartupStream,
diff --git a/deep_profiler/mdprof_fb.automatic_parallelism.m b/deep_profiler/mdprof_fb.automatic_parallelism.m
index a67ec4390..83b901b8f 100644
--- a/deep_profiler/mdprof_fb.automatic_parallelism.m
+++ b/deep_profiler/mdprof_fb.automatic_parallelism.m
@@ -92,6 +92,7 @@
 %----------------------------------------------------------------------------%
 %
 % The code in this section has some trace goals that can be enabled with:
+%
 %   --trace-flag=debug_cpc_search
 %     Debug the traversal through the clique tree.
 %
@@ -103,12 +104,12 @@
 %
 
 candidate_parallel_conjunctions(Params, Deep, Messages, !Feedback) :-
-    % Find opertunities for parallelism by walking the clique tree.  Don't
-    % Descened into cliques cheaper than the threshold.
+    % Find opportunities for parallelism by walking the clique tree.
+    % Do not descend into cliques cheaper than the threshold.
     deep_lookup_clique_index(Deep, Deep ^ root, RootCliquePtr),
     % The +1 here accounts for the cost of the pseudo call into the mercury
-    % runtime since it is modeled here as a call site that in reality does not
-    % exist.
+    % runtime since it is modeled here as a call site that in reality
+    % does not exist.
     RootParallelism = no_parallelism,
     candidate_parallel_conjunctions_clique(Params, Deep,
         RootParallelism, RootCliquePtr, ConjunctionsMap, Messages),
@@ -148,10 +149,10 @@ pard_goal_detail_annon_to_pard_goal_annon(SharedVarsSet, PGD, PG) :-
     Coverage = PGD ^ pgd_coverage,
     get_coverage_before_det(Coverage, Calls),
     ( Calls > 0 ->
-        foldl(build_var_use_list(PGD ^ pgd_var_production_map), SharedVars,
-            [], Productions),
-        foldl(build_var_use_list(PGD ^ pgd_var_consumption_map), SharedVars,
-            [], Consumptions)
+        list.foldl(build_var_use_list(PGD ^ pgd_var_production_map),
+            SharedVars, [], Productions),
+        list.foldl(build_var_use_list(PGD ^ pgd_var_consumption_map),
+            SharedVars, [], Consumptions)
     ;
         Productions = [],
         Consumptions = []
@@ -199,35 +200,35 @@ build_var_use_list(Map, Var, !List) :-
 
 :- type pard_goal_detail_annotation
     --->    pard_goal_detail(
+                % The type and type-specific values of the pard goal.
                 pgd_pg_type                 :: pard_goal_type,
-                    % The type and type-specific values of the pard goal.
 
+                % The inst map info attached to the original goal.
                 pgd_inst_map_info           :: inst_map_info,
-                    % The inst map info attached to the original goal.
 
+                % The original goal path of this goal.
                 pgd_original_path           :: goal_path,
-                    % The original goal path of this goal.
 
+                % Coverage data for this goal.
                 pgd_coverage                :: coverage_info,
-                    % Coverage data for this goal.
 
+                % The per-call cost of this call in call sequence counts.
                 pgd_cost                    :: goal_cost_csq,
-                    % The per-call cost of this call in call sequence counts.
 
                 pgd_cost_above_threshold    :: cost_above_par_threshold,
 
+                % Variable production and consumption information.
                 pgd_var_production_map      :: map(var_rep, lazy(var_use_info)),
                 pgd_var_consumption_map     :: map(var_rep, lazy(var_use_info))
-                    % Variable production and consumption information.
             ).
 
 :- type pard_goal_type
     --->    pgt_call(
+                % The argument modes and use information.
                 pgtc_args                   :: list(var_and_mode),
-                    % The argument modes and use information.
 
+                % The call site report from the deep profiler.
                 pgtc_call_site              :: cost_and_callees
-                    % The call site report from the deep profiler.
             )
     ;       pgt_other_atomic_goal
     ;       pgt_non_atomic_goal.
@@ -252,10 +253,11 @@ build_var_use_list(Map, Var, !List) :-
     %   ParentUsedParallelism, CliquePtr, CandidateParallelConjunctions,
     %   Messages)
     %
-    % Find any CandidateParallelConjunctions in this clique and it's children.
-    % We stop searching when ParentCSCost is too low that the overheads of
-    % parallelism are too great or if ParentUsedParallelism becomes greater
-    % than the desired amount of parallelism.
+    % Find any CandidateParallelConjunctions in this clique and its children.
+    % We stop searching when ParentCSCost is too low (in which case the
+    % relative overheads of parallelism would be too great), or if
+    % ParentUsedParallelism becomes greater than the desired amount
+    % of parallelism.
     %
 :- pred candidate_parallel_conjunctions_clique(
     candidate_par_conjunctions_params::in, deep::in,
@@ -277,8 +279,8 @@ candidate_parallel_conjunctions_clique(Opts, Deep, ParentParallelism,
             PDPtrs = OtherPDPtrs
         ;
             CliquePtr = clique_ptr(CliqueNum),
-            error(format("%sClique %d has no entry proc",
-                [s(this_file), i(CliqueNum)]))
+            string.format("Clique %d has no entry proc", [i(CliqueNum)], Msg),
+            unexpected($module, $pred, Msg)
         )
     ),
 
@@ -293,27 +295,29 @@ candidate_parallel_conjunctions_clique(Opts, Deep, ParentParallelism,
     ),
 
     % Look for parallelisation opportunities in this clique.
-    map2(candidate_parallel_conjunctions_clique_proc(Opts, Deep,
+    list.map2(
+        candidate_parallel_conjunctions_clique_proc(Opts, Deep,
             RecursionType, CliquePtr),
-        PDPtrs, Candidatess, Messagess),
-    foldl(union(merge_candidate_par_conjs_proc), Candidatess,
+        PDPtrs, CandidateLists, MessageCords),
+    list.foldl(map.union(merge_candidate_par_conjs_proc), CandidateLists,
         map.init, CliqueCandidates),
-    CliqueMessages = cord_list_to_cord(Messagess),
+    CliqueMessages = cord_list_to_cord(MessageCords),
 
     % Look in descendent cliques.
     some [!ChildCliques] (
         map(proc_dynamic_callees(Deep, ParentParallelism), PDPtrs,
             ChildCliquess),
         !:ChildCliques = cord_list_to_cord(ChildCliquess),
-        map2(candidate_parallel_conjunctions_callee(Opts, Deep,
+        list.map2(
+            candidate_parallel_conjunctions_callee(Opts, Deep,
                 CliquePtr, CliqueCandidates),
-            list(!.ChildCliques), CSCandidatess, CSMessagess)
+            list(!.ChildCliques), CSCandidateLists, CSMessageCords)
     ),
-    foldl(union(merge_candidate_par_conjs_proc), CSCandidatess,
+    list.foldl(map.union(merge_candidate_par_conjs_proc), CSCandidateLists,
         map.init, CSCandidates),
-    CSMessages = cord_list_to_cord(CSMessagess),
+    CSMessages = cord_list_to_cord(CSMessageCords),
 
-    union(merge_candidate_par_conjs_proc, CliqueCandidates, CSCandidates,
+    map.union(merge_candidate_par_conjs_proc, CliqueCandidates, CSCandidates,
         Candidates),
     Messages = CliqueMessages ++ CSMessages.
 
@@ -340,8 +344,9 @@ proc_dynamic_callees(Deep, Parallelism, PDPtr, ChildCliques) :-
     deep_lookup_proc_statics(Deep, PSPtr, PS),
     ProcLabel = PS ^ ps_id,
     proc_dynamic_paired_call_site_slots(Deep, PDPtr, Slots),
-    map(pd_slot_callees(Deep, Parallelism, ProcLabel), Slots, ChildCliquess),
-    ChildCliques = cord_list_to_cord(ChildCliquess).
+    list.map(pd_slot_callees(Deep, Parallelism, ProcLabel),
+        Slots, ChildCliqueCords),
+    ChildCliques = cord_list_to_cord(ChildCliqueCords).
 
 :- pred pd_slot_callees(deep::in, parallelism_amount::in,
     string_proc_label::in,
@@ -357,9 +362,10 @@ pd_slot_callees(Deep, Parallelism, ProcLabel, CSSPtr - Slot, ChildCliques) :-
             CSDPtr, ChildCliques)
     ;
         Slot = slot_multi(_, CSDPtrs),
-        map(call_site_dynamic_callees(Deep, Parallelism, ProcLabel, GoalPath),
-            to_list(CSDPtrs), ChildCliquess),
-        ChildCliques = cord_list_to_cord(ChildCliquess)
+        list.map(
+            call_site_dynamic_callees(Deep, Parallelism, ProcLabel, GoalPath),
+            to_list(CSDPtrs), ChildCliqueCords),
+        ChildCliques = cord_list_to_cord(ChildCliqueCords)
     ).
 
 :- pred call_site_dynamic_callees(deep::in, parallelism_amount::in,
@@ -402,7 +408,7 @@ candidate_parallel_conjunctions_callee(Opts, Deep, CliquePtr, CliqueCandidates,
                 AnalyzeChild = yes
             ;
                 trace [compile_time(flag("debug_cpc_search")), io(!IO)] (
-                    debug_cliques_exeeded_parallelism(!.Callee, !IO)
+                    debug_cliques_exceeded_parallelism(!.Callee, !IO)
                 ),
                 AnalyzeChild = no
             )
@@ -419,8 +425,7 @@ candidate_parallel_conjunctions_callee(Opts, Deep, CliquePtr, CliqueCandidates,
     (
         AnalyzeChild = yes,
         Parallelism = !.Callee ^ ccc_parallelism,
-        ChildCliquePtr =
-            !.Callee ^ ccc_clique,
+        ChildCliquePtr = !.Callee ^ ccc_clique,
         candidate_parallel_conjunctions_clique(Opts, Deep, Parallelism,
             ChildCliquePtr, Candidates, Messages)
     ;
@@ -470,8 +475,9 @@ update_parallelism_available_conj(Conj, !ChildClique) :-
     goal_path_from_string_det(Conj ^ cpc_goal_path, ConjGoalPath),
     % XXX: This needs revisiting if we allow parallelised conjuncts to be
     % re-ordered.
-    FirstConjunct = Conj ^ cpc_first_conj_num + length(Conj ^ cpc_goals_before),
-    Length = foldl((func(seq_conj(ConjsI), Acc) = Acc + length(ConjsI)),
+    FirstConjunct = Conj ^ cpc_first_conj_num +
+        length(Conj ^ cpc_goals_before),
+    Length = list.foldl((func(seq_conj(ConjsI), Acc) = Acc + length(ConjsI)),
         Conj ^ cpc_conjs, 0),
     (
         GoalPath \= ConjGoalPath,
@@ -555,8 +561,7 @@ merge_candidate_par_conjs_proc(A, B, Result) :-
     ( VarTableA = VarTableB ->
         true
     ;
-        error(this_file ++
-            "merge_candidate_par_conjs_proc: var tables do not match")
+        unexpected($module, $pred, "var tables do not match")
     ).
 
 %----------------------------------------------------------------------------%
@@ -591,8 +596,8 @@ candidate_parallel_conjunctions_proc(Opts, Deep, PDPtr, RecursionType,
             ; ModuleName = "exception"
             )
         ->
-            % Silently skip over any code from the runtime, we can't expect to
-            % find it's procedure representation.
+            % Silently skip over any code from the runtime, since
+            % we can't expect to find its procedure representation.
             Candidates = map.init
         ;
             create_dynamic_procrep_coverage_report(Deep, PDPtr,
@@ -608,9 +613,9 @@ candidate_parallel_conjunctions_proc(Opts, Deep, PDPtr, RecursionType,
                 proc_dynamic_paired_call_site_slots(Deep, PDPtr, Slots),
                 foldl(build_call_site_cost_and_callee_map(Deep), Slots,
                     map.init, CallSitesMap),
-                Info = implicit_parallelism_info(Deep, ProgRep, Opts, CliquePtr,
-                    CallSitesMap, RecursiveCallSiteCostMap, RecursionType,
-                    VarTable, ProcLabel),
+                Info = implicit_parallelism_info(Deep, ProgRep, Opts,
+                    CliquePtr, CallSitesMap, RecursiveCallSiteCostMap,
+                    RecursionType, VarTable, ProcLabel),
                 some [!Goal] (
                     !:Goal = Goal0,
                     goal_annotate_with_instmap(!Goal,
@@ -624,7 +629,8 @@ candidate_parallel_conjunctions_proc(Opts, Deep, PDPtr, RecursionType,
                 (
                     SeenDuplicateInstantiation =
                         have_not_seen_duplicate_instantiation,
-                    list.foldl(build_candidate_par_conjunction_maps(ProcLabel,
+                    list.foldl(
+                        build_candidate_par_conjunction_maps(ProcLabel,
                             VarTable),
                         Candidates0, map.init, Candidates)
                 ;
@@ -651,10 +657,11 @@ candidate_parallel_conjunctions_proc(Opts, Deep, PDPtr, RecursionType,
             ).
 
 :- instance goal_annotation_add_instmap(coverage_info,
-            coverage_and_instmap_info) where [
-        add_instmap(InstMap, Coverage,
-            coverage_and_instmap_info(Coverage, InstMap))
-    ].
+    coverage_and_instmap_info) where
+[
+    add_instmap(InstMap, Coverage,
+        coverage_and_instmap_info(Coverage, InstMap))
+].
 
 :- pred build_candidate_par_conjunction_maps(string_proc_label::in,
     var_table::in, candidate_par_conjunction(pard_goal_detail)::in,
@@ -667,8 +674,7 @@ build_candidate_par_conjunction_maps(ProcLabel, VarTable, Candidate, !Map) :-
         ( VarTable = VarTablePrime ->
             true
         ;
-            error(this_file ++
-                "build_candidate_par_conjunction_maps: Var tables do not match")
+            unexpected($module, $pred, "var tables do not match")
         )
     ;
         CPCs = [ Candidate ]
@@ -690,8 +696,8 @@ goal_get_conjunctions_worth_parallelising(Info, GoalPath, !Goal, Candidates,
     (
         (
             GoalExpr0 = conj_rep(Conjs0),
-            map3_foldl(conj_get_conjunctions_worth_parallelising(Info,
-                    GoalPath),
+            list.map3_foldl(
+                conj_get_conjunctions_worth_parallelising(Info, GoalPath),
                 Conjs0, Conjs, Candidatess, Messagess, 1, _),
             conj_build_candidate_conjunctions(Info, GoalPath, Conjs,
                 MaybeCost, MessagesB, MaybeCandidate),
@@ -712,8 +718,8 @@ goal_get_conjunctions_worth_parallelising(Info, GoalPath, !Goal, Candidates,
             )
         ;
             GoalExpr0 = disj_rep(Disjs0),
-            map3_foldl(disj_get_conjunctions_worth_parallelising(Info,
-                    GoalPath),
+            list.map3_foldl(
+                disj_get_conjunctions_worth_parallelising(Info, GoalPath),
                 Disjs0, Disjs, Candidatess, Messagess, 1, _),
             disj_calc_cost(Disjs, Calls, Cost),
             GoalExpr = disj_rep(Disjs),
@@ -721,7 +727,8 @@ goal_get_conjunctions_worth_parallelising(Info, GoalPath, !Goal, Candidates,
             Candidates = condense(Candidatess)
         ;
             GoalExpr0 = switch_rep(Var, CanFail, Cases0),
-            map3_foldl(switch_case_get_conjunctions_worth_parallelising(Info,
+            list.map3_foldl(
+                switch_case_get_conjunctions_worth_parallelising(Info,
                     GoalPath),
                 Cases0, Cases, Candidatess, Messagess, 1, _),
             switch_calc_cost(Cases, Calls, Cost),
@@ -823,13 +830,13 @@ ite_get_conjunctions_worth_parallelising(Info, GoalPath, !Cond, !Then, !Else,
     Candidates = CondCandidates ++ ThenCandidates ++ ElseCandidates,
     Messages = CondMessages ++ ThenMessages ++ ElseMessages.
 
-    % At the end of every conjunction we call this predicate to check the list
-    % of calls we've found and make any parallelisation decisions.
+    % At the end of every conjunction, we call this predicate to check
+    % the list of calls we have found and make any parallelisation decisions.
     %
 :- pred conj_build_candidate_conjunctions(implicit_parallelism_info::in,
     goal_path::in, list(pard_goal_detail)::in, maybe(goal_cost_csq)::out,
-    cord(message)::out, maybe(candidate_par_conjunction(pard_goal_detail))::out)
-    is det.
+    cord(message)::out,
+    maybe(candidate_par_conjunction(pard_goal_detail))::out) is det.
 
 conj_build_candidate_conjunctions(Info, GoalPath, Conjs, MaybeCost, Messages,
         MaybeCandidate) :-
@@ -943,8 +950,8 @@ pardgoals_build_candidate_conjunction(Info, Location, GoalPath, Goals,
                         ++ "proc or goal")
                 ),
 
-                convert_candidate_par_conjunction(pard_goal_detail_to_pard_goal,
-                    Candidate, FBCandidate),
+                convert_candidate_par_conjunction(
+                    pard_goal_detail_to_pard_goal, Candidate, FBCandidate),
                 VarTable = Info ^ ipi_var_table,
                 create_candidate_parallel_conj_report(VarTable,
                     ProcLabel, FBCandidate, Report),
@@ -1117,7 +1124,7 @@ preprocess_conjunction(Goals, MaybeGoalsForParallelisation, Location,
         FirstCostlyGoalIndex = FirstCostlyGoalIndexPrime,
         LastCostlyGoalIndex = LastCostlyGoalIndexPrime
     ;
-        error(this_file ++ "too few costly goals")
+        unexpected($module, $pred, "too few costly goals")
     ),
 
     % Phase 3: Check that all the middle goals are model det.
@@ -1216,7 +1223,7 @@ goal_accumulate_detism(_, Goal, !Detism) :-
     ->
         !:Detism = FinalDetism
     ;
-        error(this_file ++ "Cannot compute detism from components.")
+        unexpected($module, $pred, "cannot compute detism from components.")
     ).
 
     % foldl(preprocess_conjunction_into_groups, Goals, FirstCostlyGoalIndex,
@@ -1306,9 +1313,10 @@ find_best_parallelisation_complete_bnb(Info, Location, Algorithm,
         )
     ).
 
-    % The objective function for the branch and bound search.  This is ParTime
-    % + ParOverheads * 2.  That is we're willing to pay 1 unit of parallel
-    % overheads to get a 2 unit improvement of parallel execution time.
+    % The objective function for the branch and bound search.
+    % This is ParTime + ParOverheads * 2.  That is we are willing to pay
+    % 1 unit of parallel overheads to get a 2 unit improvement
+    % of parallel execution time.
     %
 :- func parallelisation_get_objective_value(best_parallelisation) = float.
 
@@ -1334,8 +1342,8 @@ generate_parallelisations(Info, Algorithm, GoalsForParallelisation,
         (
             semipure should_expand_search(BNBState, Algorithm)
         ->
-            % Try to push goals into the first and last parallel conjuncts from
-            % outside the parallel conjunction.
+            % Try to push goals into the first and last parallel conjuncts
+            % from outside the parallel conjunction.
             semipure add_goals_into_first_par_conj(BNBState, !Parallelisation),
             semipure add_goals_into_last_par_conj(BNBState, !Parallelisation)
         ;
@@ -1390,8 +1398,8 @@ add_goals_into_last_par_conj(BNBState, !Parallelisation) :-
     ).
 
     % Set the last scheduled goal to the goal at the end of the first group,
-    % popping the first group off the list.  This initialises the
-    % parallelistion with the first goal group occurring first in the first
+    % popping the first group off the list. This initialises the
+    % parallelisation with the first goal group occurring first in the first
     % parallel conjunction.
     %
     % This is done outside of the loop below since the first goal group will
@@ -1404,7 +1412,7 @@ add_goals_into_last_par_conj(BNBState, !Parallelisation) :-
 start_first_par_conjunct(!GoalGroups, !Parallelisation) :-
     (
         !.GoalGroups = [],
-        error(this_file ++ "No goal groups.")
+        unexpected($module, $pred, "no goal groups")
     ;
         !.GoalGroups = [Group | !:GoalGroups],
         gg_get_details(Group, Index, Num, _),
@@ -1431,7 +1439,8 @@ generate_parallelisations_body(Info, BNBState, Algorithm,
         !:AddToNewParallelisation = !.Parallelisation,
 
         % Consider adding this goal to the last parallel conjunct.
-        !AddToLastParallelisation ^ ip_last_scheduled_goal := LastScheduledGoal,
+        !AddToLastParallelisation ^ ip_last_scheduled_goal
+            := LastScheduledGoal,
         score_parallelisation(BNBState, MaybeAddToLastScore,
             !AddToLastParallelisation),
 
@@ -1523,7 +1532,8 @@ should_expand_search(BNBState, Algorithm) :-
     % bound solver.
     %
 :- semipure pred test_parallelisation(bnb_state(best_parallelisation)::in,
-    incomplete_parallelisation::in, incomplete_parallelisation::out) is semidet.
+    incomplete_parallelisation::in, incomplete_parallelisation::out)
+    is semidet.
 
 test_parallelisation(BNBState, !Parallelisation) :-
     calculate_parallel_cost(CostData, !Parallelisation),
@@ -1551,8 +1561,8 @@ score_parallelisation(BNBState, MaybeScore, !Parallelisation) :-
         MaybeScore = no
     ).
 
-    % Test that the parallelisation only included dependant parallelism if
-    % permitted by the user.
+    % Test that the parallelisation only included dependant parallelism
+    % if permitted by the user.
     %
 :- pred test_dependance(implicit_parallelism_info::in,
     parallelisation_cost_data::in) is semidet.
@@ -1583,7 +1593,7 @@ test_dependance(Info, CostData) :-
                 % The index of the last goal in the parallel conjunction.
                 ip_last_par_goal            :: int,
 
-                % The index of the last goal that has been (tentativly)
+                % The index of the last goal that has been (tentatively)
                 % scheduled.  All goals between this +1 and ip_last_par_goal
                 % have not been scheduled.
                 ip_last_scheduled_goal      :: int,
@@ -1677,8 +1687,9 @@ start_building_parallelisation(Info, PreprocessedGoals, Parallelisation) :-
     LastParGoal = PreprocessedGoals ^ gfp_last_costly_goal,
     NumCalls = PreprocessedGoals ^ gfp_num_calls,
     DependencyGraphs = PreprocessedGoals ^ gfp_dependency_graphs,
-    Parallelisation = incomplete_parallelisation(Info, GoalsArray, FirstParGoal,
-        LastParGoal, FirstParGoal, [], NumCalls, DependencyGraphs, no, no, no).
+    Parallelisation = incomplete_parallelisation(Info, GoalsArray,
+        FirstParGoal, LastParGoal, FirstParGoal, [], NumCalls,
+        DependencyGraphs, no, no, no).
 
     % Finalise the parallelisation.
     %
@@ -1694,8 +1705,7 @@ finalise_parallelisation(Incomplete, Best) :-
         MaybeCostData = yes(CostData)
     ;
         MaybeCostData = no,
-        error(this_file ++ "finalise_parallelisation: "
-            ++ "Parallelisation has no cost data")
+        unexpected($module, $pred, "parallelisation has no cost data")
     ),
     CostData = parallelisation_cost_data(Overlap, Metrics0, _),
 
@@ -1744,17 +1754,17 @@ add_one_goal_into_last_par_conj(!Parallelisation) :-
 
 :- type dependent_conjunct_execution
     --->    dependent_conjunct_execution(
+                % Pairs of start and stop times of the execution.
+                % Assume that the list is not sorted.
                 dce_execution           :: assoc_list(float, float),
-                    % Pairs of start and stop times of the execution.  Assume
-                    % that the list is not sorted.
 
+                % The variable productions. This may be a superset of the
+                % dependent variables.
                 dce_productions         :: map(var_rep, float),
-                    % The variable productions.  This may be a superset of the
-                    % dependent variables.
 
+                % The variable consumptions. This will contain only
+                % references for those variables that will become futures.
                 dce_consumptions        :: map(var_rep, float)
-                    % The variable consumptions.  This will contain only
-                    % references for those variables that will become futures.
             ).
 
     % calculate_parallel_cost(Info, !Parallelisation).
@@ -1858,13 +1868,13 @@ calculate_parallel_cost_step(Info, IsLastConjunct, Conjunct, !ConjNum,
     Vars = set.intersect(ProducedVars, RightConsumedVars),
 
     % This conjunct will actually start after it has been sparked by
-    % the prevous conjunct.  Which in turn may have been sparked by an
+    % the previous conjunct, which in turn may have been sparked by an
     % earlier conjunct.
     SparkDelay = Info ^ ipi_opts ^ cpcp_sparking_delay,
     StartTime0 = float((!.ConjNum - 1) * SparkDelay),
 
-    % If there are conjuncts after this conjunct we will have the
-    % additional cost of sparking them.
+    % If there are conjuncts after this conjunct, we will have
+    % the additional cost of sparking them.
     (
         IsLastConjunct = not_last_par_conjunct,
         SparkCost = Info ^ ipi_opts ^ cpcp_sparking_cost,
@@ -1877,8 +1887,8 @@ calculate_parallel_cost_step(Info, IsLastConjunct, Conjunct, !ConjNum,
     (
         Algorithm = parallelise_dep_conjs_overlap,
 
-        % Get the list of variables consumed by this conjunct that will be
-        % turned into futures.
+        % Get the list of variables consumed by this conjunct
+        % that will be turned into futures.
         foldl3(get_consumptions_list, Conjunct, Vars, _, 0.0, _,
             [], ConsumptionsList0),
         reverse(ConsumptionsList0, ConsumptionsList),
@@ -1889,8 +1899,8 @@ calculate_parallel_cost_step(Info, IsLastConjunct, Conjunct, !ConjNum,
             StartTime, LastParConsumeTime, StartTime, LastResumeTime,
             [], RevExecution0, map.init, ConsumptionsMap),
 
-        % Calculate the point at which this conjunct finishes execution and
-        % complete the RevExecutions structure..
+        % Calculate the point at which this conjunct finishes execution
+        % and complete the RevExecutions structure..
         reverse(RevExecution, Execution),
         CostBPar = LastParConsumeTime + (CostB - LastSeqConsumeTime),
         RevExecution = [ (LastResumeTime - CostBPar) | RevExecution0 ],
@@ -1912,8 +1922,8 @@ calculate_parallel_cost_step(Info, IsLastConjunct, Conjunct, !ConjNum,
     !:Metrics = init_parallel_exec_metrics_incomplete(!.Metrics, CostSignals,
         CostB, CostBPar),
 
-    % Build the productions map for the next conjunct.  This map contains all
-    % the variables produced by this code, not just that are used for
+    % Build the productions map for the next conjunct. This map contains
+    % all the variables produced by this code, not just that are used for
     % dependent parallelisation.
     foldl3(get_productions_map, Conjunct, StartTime, _, Execution, _,
         !ProductionsMap),
@@ -1968,11 +1978,11 @@ calculate_dependent_parallel_cost_2(Info, ProductionsMap, Var - SeqConsTime,
 
     % Consider (P & Q):
     %
-    % Q cannot consume the variable until P produces it.  Also Q cannot consume
-    % the variable until it is ready for it.  These are the two parameters to
+    % Q cannot consume the variable until P produces it. Also Q cannot consume
+    % the variable until it is ready for it. These are the two parameters to
     % max/2.
     %
-    % The second parameter can be explained further, Q may have waited on a
+    % The second parameter can be explained further. Q may have waited on a
     % future previously, if so !.PrevParConsumeTime is when it finished
     % waiting, and SeqConsTime - !.PrevSeqConsumeTime is how long Q will take
     % between the two waits.
@@ -1984,8 +1994,8 @@ calculate_dependent_parallel_cost_2(Info, ProductionsMap, Var - SeqConsTime,
         float(Info ^ ipi_opts ^ cpcp_future_wait_cost),
 
     (
-        % True if Q had to suspend waiting for P,  Not that we don't include
-        % FutureSyncTime here.  This is true if Q has to block at all even if
+        % True if Q had to suspend waiting for P. Note that we don't include
+        % FutureSyncTime here. This is true if Q has to block at all even if
         % it can be made runable before the context switch is complete.
         ProdTime > ParConsTimeNotBlocked
     ->
@@ -1993,7 +2003,7 @@ calculate_dependent_parallel_cost_2(Info, ProductionsMap, Var - SeqConsTime,
         ParConsTime = ParConsTime0 +
             float(Info ^ ipi_opts ^ cpcp_context_wakeup_delay),
         !:RevExecution =
-            [ (!.ResumeTime - ParConsTimeNotBlocked) | !.RevExecution ],
+            [(!.ResumeTime - ParConsTimeNotBlocked) | !.RevExecution],
         !:ResumeTime = ParConsTime
     ;
         ParConsTime = ParConsTime0
@@ -2024,27 +2034,26 @@ par_conj_overlap_is_dependent(peo_conjunction(Left, _, VarSet0), IsDependent) :-
     ).
 
 :- type dependency_graphs
-    ---> dependency_graphs(
-            dm_forward              :: digraph(int),
-            dm_forward_tc           :: digraph(int)
-        ).
+    --->    dependency_graphs(
+                dm_forward              :: digraph(int),
+                dm_forward_tc           :: digraph(int)
+            ).
 
 :- pred build_dependency_graphs(list(pard_goal_detail)::in,
     dependency_graphs::out) is det.
 
 build_dependency_graphs(Goals, Maps) :-
     Graph0 = digraph.init,
-    build_dependency_graph(Goals, 1, map.init, _VarDepMap,
-        Graph0, Graph),
+    build_dependency_graph(Goals, 1, map.init, _VarDepMap, Graph0, Graph),
     Maps = dependency_graphs(Graph, tc(Graph)).
 
 :- pred depends_lookup(dependency_graphs::in, int::in, set(int)::out) is det.
 
 depends_lookup(DependencyGraphs, GoalNum, Deps) :-
-    graph_do_lookup(lookup_from, DependencyGraphs ^ dm_forward, GoalNum,
-        Deps).
+    graph_do_lookup(lookup_from, DependencyGraphs ^ dm_forward, GoalNum, Deps).
 
-:- pred depends_lookup_tc(dependency_graphs::in, int::in, set(int)::out) is det.
+:- pred depends_lookup_tc(dependency_graphs::in, int::in, set(int)::out)
+    is det.
 
 depends_lookup_tc(DependencyGraphs, GoalNum, Deps) :-
     graph_do_lookup(lookup_from, DependencyGraphs ^ dm_forward_tc, GoalNum,
@@ -2213,11 +2222,11 @@ get_consumptions_list(Goal, !Vars, !Time, !List) :-
     ConsumptionVars = intersect(!.Vars, AllConsumptionVars),
     map(var_consumptions(!.Time, Goal),
         ConsumptionVars, ConsumptionTimesSet0),
-    % Since we re-sort the list we don't need a sorted one to start with, but
-    % the set module doesn't export a "to_list" predicate,  (Sorting has no
-    % cost since the set is a sorted list internally).
+    % Since we re-sort the list we don't need a sorted one to start with,
+    % but the set module doesn't export a "to_list" predicate. (Getting
+    % a sorted list has no cost since the set is a sorted list internally).
     set.to_sorted_list(ConsumptionTimesSet0, ConsumptionTimes0),
-    sort((pred((_ - TimeA)::in, (_ - TimeB)::in, Result::out) is det :-
+    list.sort((pred((_ - TimeA)::in, (_ - TimeB)::in, Result::out) is det :-
             % Note that the Time arguments are swapped, this list must be
             % produced in latest to earliest order.
             compare(Result, TimeB, TimeA)
@@ -2302,7 +2311,7 @@ pardgoal_consumed_vars_accum(Goal, !Vars) :-
     RefedVars = Goal ^ goal_annotation ^ pgd_inst_map_info ^ im_consumed_vars,
     set.union(RefedVars, !Vars).
 
-    % Check if it is appropriate to parallelise this call.  That is it must be
+    % Check if it is appropriate to parallelise this call. That is it must be
     % model_det and have a cost above the call site cost threshold.
     %
 :- pred can_parallelise_goal(goal_rep(T)::in) is semidet.
@@ -2432,12 +2441,12 @@ compute_var_use_lazy(Info, GoalPath, Var, Args, VarUseType) = Use :-
             Uses = [Use]
         ;
             Uses = [_, _ | _],
-            error(this_file ++ "Too many solutions to compute_var_use_lazy_arg"
-                ++ " for a production")
+            unexpected($module, $pred, "Too many solutions ")
         )
     ).
 
-:- pred earliest_use(var_use_info::in, var_use_info::in, var_use_info::out) is det.
+:- pred earliest_use(var_use_info::in, var_use_info::in, var_use_info::out)
+    is det.
 
 earliest_use(A, B, Ealiest) :-
     TimeA = A ^ vui_cost_until_use,
@@ -2452,7 +2461,8 @@ earliest_use(A, B, Ealiest) :-
     list(var_rep)::in, cost_and_callees::in, cs_cost_csq::in, var_use_type::in,
     var_use_info::out) is multi.
 
-compute_var_use_lazy_arg(Info, Var, Args, CostAndCallee, Cost, VarUseType, Use) :-
+compute_var_use_lazy_arg(Info, Var, Args, CostAndCallee, Cost, VarUseType,
+        Use) :-
     ( 0.0 < cs_cost_get_calls(Cost) ->
         CostPercall = cs_cost_get_percall(Cost),
         ( member_index0(Var, Args, ArgNum) ->
@@ -2466,8 +2476,8 @@ compute_var_use_lazy_arg(Info, Var, Args, CostAndCallee, Cost, VarUseType, Use)
                 ( singleton_set(CostAndCallee ^ cac_callees, CalleePrime) ->
                     Callee = CalleePrime
                 ;
-                    error(this_file ++
-                        "First-order call site has wrong number of CSDs")
+                    unexpected($module, $pred,
+                        "first-order call site has wrong number of CSDs")
                 ),
                 CSDPtr = Callee ^ c_csd,
                 RecursionType = Info ^ ipi_recursion_type,
@@ -2482,8 +2492,13 @@ compute_var_use_lazy_arg(Info, Var, Args, CostAndCallee, Cost, VarUseType, Use)
             )
         ;
             Use = var_use_info(0.0, CostPercall, VarUseType),
-            require(unify(VarUseType, var_use_consumption), this_file ++
-                "Var use type most be consumption if \\+ member(Var, Args)")
+            ( unify(VarUseType, var_use_consumption) ->
+                true
+            ;
+                unexpected($module, $pred,
+                    "Var use type most be consumption if " ++
+                    "\\+ member(Var, Args)")
+            )
         )
     ;
         % This call site is never called.
@@ -2626,7 +2641,7 @@ identify_costly_goal(Goal, Costly) :-
             Costly = is_costly_atomic_goal
         ;
             GoalType = pgt_other_atomic_goal,
-            error(this_file ++ "pgt_other_atomic_goal is never costly")
+            unexpected($module, $pred, "pgt_other_atomic_goal is never costly")
         ;
             GoalType = pgt_non_atomic_goal,
             % TODO: distinguish between compound goals with one branch that is
@@ -2641,8 +2656,8 @@ identify_costly_goal(Goal, Costly) :-
         Costly = is_not_costly_goal
     ).
 
-:- pred var_get_mode(inst_map::in, inst_map::in, var_rep::in, var_mode_rep::out)
-    is det.
+:- pred var_get_mode(inst_map::in, inst_map::in, var_rep::in,
+    var_mode_rep::out) is det.
 
 var_get_mode(InstMapBefore, InstMapAfter, VarRep, VarModeRep) :-
     inst_map_get(InstMapBefore, VarRep, InstBefore, _),
@@ -2663,20 +2678,20 @@ goal_to_pard_goal(Info, GoalPath, !Goal, !Messages) :-
     (
         (
             GoalExpr0 = conj_rep(Conjs0),
-            map_foldl2(conj_to_pard_goals(Info, GoalPath), Conjs0, Conjs, 1, _,
-                !Messages),
+            list.map_foldl2(conj_to_pard_goals(Info, GoalPath), Conjs0, Conjs,
+                1, _, !Messages),
             conj_calc_cost(Conjs, Before, Cost),
             GoalExpr = conj_rep(Conjs)
         ;
             GoalExpr0 = disj_rep(Disjs0),
-            map_foldl2(disj_to_pard_goals(Info, GoalPath), Disjs0, Disjs, 1, _,
-                !Messages),
+            list.map_foldl2(disj_to_pard_goals(Info, GoalPath), Disjs0, Disjs,
+                1, _, !Messages),
             disj_calc_cost(Disjs, Before, Cost),
             GoalExpr = disj_rep(Disjs)
         ;
             GoalExpr0 = switch_rep(Var, CanFail, Cases0),
-            map_foldl2(case_to_pard_goal(Info, GoalPath), Cases0, Cases, 1, _,
-                !Messages),
+            list.map_foldl2(case_to_pard_goal(Info, GoalPath), Cases0, Cases,
+                1, _, !Messages),
             switch_calc_cost(Cases, Before, Cost),
             GoalExpr = switch_rep(Var, CanFail, Cases)
         ;
@@ -2709,7 +2724,8 @@ goal_to_pard_goal(Info, GoalPath, !Goal, !Messages) :-
         PardGoalType = pgt_non_atomic_goal,
 
         BoundVars = to_sorted_list(InstMapInfo ^ im_bound_vars),
-        foldl(goal_build_use_map(!.Goal, GoalPath, Cost, Info,
+        list.foldl(
+            goal_build_use_map(!.Goal, GoalPath, Cost, Info,
                 var_use_production),
             BoundVars, map.init, ProductionUseMap),
         ConsumedVars = to_sorted_list(InstMapInfo ^ im_consumed_vars),
@@ -2723,11 +2739,13 @@ goal_to_pard_goal(Info, GoalPath, !Goal, !Messages) :-
             PardGoalType, Messages),
         atomic_pard_goal_cost(Info, GoalPath, Coverage, AtomicGoal, Cost),
 
-        foldl(atomic_goal_build_use_map(AtomicGoal, GoalPath, Info,
+        list.foldl(
+            atomic_goal_build_use_map(AtomicGoal, GoalPath, Info,
                 var_use_production),
             BoundVars, map.init, ProductionUseMap),
         ConsumedVars = InstMapInfo ^ im_consumed_vars,
-        foldl(atomic_goal_build_use_map(AtomicGoal, GoalPath, Info,
+        list.foldl(
+            atomic_goal_build_use_map(AtomicGoal, GoalPath, Info,
                 var_use_consumption),
             to_sorted_list(ConsumedVars), map.init, ConsumptionUseMap),
 
@@ -2855,31 +2873,30 @@ simple_goal_cost(Calls) = Cost :-
 % Annotate a goal with instantiation information.
 %
 
-    % inst_map_info now contains information that it's not necessary to
-    % contain.  Namely the im_after field can be calculated from the im_before
-    % and im_bound_vars fields.  However since this information will probably
+    % inst_map_info now contains information that it does not need to contain.
+    % Namely, the im_after field can be calculated from the im_before and
+    % im_bound_vars fields.  However since this information will probably
     % be attached to a different goal there is not much extra cost in having a
     % pointer to it from here.
     %
 :- type inst_map_info
     --->    inst_map_info(
+                % The inst map before this goal is executed.
                 im_before           :: inst_map,
-                    % The inst map before this goal is executed.
 
+                % The inst map after this goal was executed.
                 im_after            :: inst_map,
-                    % The inst map after this goal was executed.
 
+                % Variables consumed (read but not bound) by this goal.
                 im_consumed_vars    :: set(var_rep),
-                    % Variables consumed (read but not bound) by this goal.
 
+                % The variables produced by this goal.
                 im_bound_vars       :: set(var_rep)
-                    % The variables produced by this goal.
             ).
 
 :- typeclass goal_annotation_add_instmap(A, B) where [
-        pred add_instmap(inst_map_info, A, B),
-        mode add_instmap(in, in, out) is det
-    ].
+    pred add_instmap(inst_map_info::in, A::in, B::out) is det
+].
 
     % Note: It may be useful to add other annotations such as goal path or cost
     % information.
@@ -3055,8 +3072,9 @@ switch_annotate_with_instmap([Case0 | Cases0], [Case | Cases],
     seen_duplicate_instantiation::out, set(var_rep)::out, set(var_rep)::out)
     is det <= goal_annotation_add_instmap(A, B).
 
-ite_annotate_with_instmap(Cond0, Cond, Then0, Then, Else0, Else, InstMap0, InstMap,
-        SeenDuplicateInstantiation, ConsumedVars, BoundVars) :-
+ite_annotate_with_instmap(Cond0, Cond, Then0, Then, Else0, Else,
+        InstMap0, InstMap, SeenDuplicateInstantiation,
+        ConsumedVars, BoundVars) :-
     goal_annotate_with_instmap(Cond0, Cond, InstMap0, InstMapAfterCond,
         SeenDuplicateInstantiationCond, ConsumedVarsCond, _BoundVarsCond),
     goal_annotate_with_instmap(Then0, Then, InstMapAfterCond, InstMapAfterThen,
@@ -3202,12 +3220,6 @@ css_to_call(Deep, CSS, Call) :-
 % Useful utility predicates.
 %
 
-:- func this_file = string.
-
-this_file = "mdprof_fb.automatic_parallelism.m: ".
-
-%-----------------------------------------------------------------------------%
-
 create_candidate_parallel_conj_proc_report(Proc - CandidateParConjunctionProc,
         Report) :-
     CandidateParConjunctionProc =
@@ -3228,7 +3240,6 @@ create_candidate_parallel_conj_report(VarTable, Proc, CandidateParConjunction,
         GoalsAfter, GoalsAfterCost, ParExecMetrics),
     ParExecMetrics = parallel_exec_metrics(NumCalls, SeqTime, ParTime,
         ParOverheads, FirstConjDeadTime, FutureDeadTime),
-
     (
         IsDependent = conjuncts_are_independent,
         DependanceString = "no"
@@ -3241,18 +3252,19 @@ create_candidate_parallel_conj_report(VarTable, Proc, CandidateParConjunction,
     Speedup = parallel_exec_metrics_get_speedup(ParExecMetrics),
     TimeSaving = parallel_exec_metrics_get_time_saving(ParExecMetrics),
     TotalDeadTime = FirstConjDeadTime + FutureDeadTime,
-    format("      %s\n" ++
-           "      Path: %s\n" ++
-           "      Dependent: %s\n" ++
-           "      NumCalls: %s\n" ++
-           "      SeqTime: %s\n" ++
-           "      ParTime: %s\n" ++
-           "      ParOverheads: %s\n" ++
-           "      Speedup: %s\n" ++
-           "      Time saving: %s\n" ++
-           "      First conj dead time: %s\n" ++
-           "      Future dead time: %s\n" ++
-           "      Total dead time: %s\n\n",
+    string.format(
+        "      %s\n" ++
+        "      Path: %s\n" ++
+        "      Dependent: %s\n" ++
+        "      NumCalls: %s\n" ++
+        "      SeqTime: %s\n" ++
+        "      ParTime: %s\n" ++
+        "      ParOverheads: %s\n" ++
+        "      Speedup: %s\n" ++
+        "      Time saving: %s\n" ++
+        "      First conj dead time: %s\n" ++
+        "      Future dead time: %s\n" ++
+        "      Total dead time: %s\n\n",
         [s(ProcString),
          s(GoalPathString),
          s(DependanceString),
@@ -3271,7 +3283,7 @@ create_candidate_parallel_conj_report(VarTable, Proc, CandidateParConjunction,
     ( goal_path_from_string(GoalPathString, GoalPathPrime) ->
         GoalPath = GoalPathPrime
     ;
-        error(this_file ++ "couldn't parse goal path.")
+        unexpected($module, $pred, "couldn't parse goal path")
     ),
     some [!ConjNum] (
         !:ConjNum = FirstConjNum,
@@ -3310,8 +3322,8 @@ format_parallel_conjunction(VarTable, Indent, GoalPath0, ConjNum, Conjs,
     int::in, list(seq_conj(pard_goal))::in,
     cord(string)::in, cord(string)::out) is det.
 
-format_parallel_conjuncts(_VarTable, Indent, _GoalPath, _ConjNum0, [],
-        !Report) :-
+format_parallel_conjuncts(_VarTable, Indent, _GoalPath, _ConjNum0,
+        [], !Report) :-
     IndentStr = indent(Indent),
     !:Report = snoc(!.Report ++ IndentStr, ")\n").
 format_parallel_conjuncts(VarTable, Indent, GoalPath0, ConjNum0,
@@ -3319,7 +3331,7 @@ format_parallel_conjuncts(VarTable, Indent, GoalPath0, ConjNum0,
     Conj = seq_conj(Goals),
     (
         Goals = [],
-        error(this_file ++ " empty conjunct in parallel conjunction")
+        unexpected($module, $pred, "empty conjunct in parallel conjunction")
     ;
         Goals = [Goal | GoalsTail],
         GoalPath = goal_path_add_at_end(GoalPath0, step_conj(ConjNum0)),
@@ -3361,7 +3373,8 @@ format_sequential_conjunction(VarTable, Indent, GoalPath, Goals, Cost,
             singleton(format("%% conjunction: %s",
                 [s(goal_path_to_string(GoalPath))])) ++
             nl_indent(Indent) ++
-            singleton(format("%% Cost: %s", [s(two_decimal_fraction(Cost))])) ++
+            singleton(format("%% Cost: %s",
+                [s(two_decimal_fraction(Cost))])) ++
             nl ++ nl
     ;
         true
@@ -3390,9 +3403,8 @@ format_sequential_conjuncts(VarTable, Indent, GoalPath0, [Conj | Conjs],
     ).
 
 :- instance goal_annotation(pard_goal_annotation) where [
-        pred(print_goal_annotation_to_strings/3) is
-            format_pard_goal_annotation
-    ].
+    pred(print_goal_annotation_to_strings/3) is format_pard_goal_annotation
+].
 
 :- pred format_pard_goal_annotation(var_table::in, pard_goal_annotation::in,
     cord(cord(string))::out) is det.
@@ -3408,8 +3420,7 @@ format_pard_goal_annotation(VarTable, GoalAnnotation, Report) :-
         CostAboveThresholdStr = "not above threshold"
     ),
     CostLine = singleton(format("cost: %s (%s)",
-            [s(two_decimal_fraction(CostPercall)),
-             s(CostAboveThresholdStr)])),
+        [s(two_decimal_fraction(CostPercall)), s(CostAboveThresholdStr)])),
     format_var_use_report(VarTable, productions, Productions,
         ProductionsReport),
     format_var_use_report(VarTable, consumptions, Consumptions,
@@ -3454,19 +3465,21 @@ debug_cliques_below_threshold(Clique, !IO) :-
     CliquePtr = clique_ptr(CliqueNum),
     Calls = cs_cost_get_calls(Clique ^ ccc_cs_cost),
     PercallCost = cs_cost_get_percall(Clique ^ ccc_cs_cost),
-    io.format("D: Not entering clique: %d, " ++
-        "it is below the clique threashold\n  " ++
+    io.format(
+        "D: Not entering clique: %d, " ++
+        "it is below the clique threshold\n  " ++
         "It has per-call cost %f and is called %f times\n\n",
         [i(CliqueNum), f(PercallCost), f(Calls)], !IO).
 
-:- pred debug_cliques_exeeded_parallelism(candidate_child_clique::in,
+:- pred debug_cliques_exceeded_parallelism(candidate_child_clique::in,
     io::di, io::uo) is det.
 
-debug_cliques_exeeded_parallelism(Clique, !IO) :-
+debug_cliques_exceeded_parallelism(Clique, !IO) :-
     CliquePtr = Clique ^ ccc_clique,
     CliquePtr = clique_ptr(CliqueNum),
-    io.format("D: Not entiring clique %d, " ++
-        "no-more parallelisation resources available at this context\n\n",
+    io.format(
+        "D: Not entiring clique %d, " ++
+        "no more parallelisation resources available at this context\n\n",
         [i(CliqueNum)], !IO).
 
 %-----------------------------------------------------------------------------%
diff --git a/deep_profiler/mdprof_fb.m b/deep_profiler/mdprof_fb.m
index 42b3d1b43..b5c7bfd1a 100644
--- a/deep_profiler/mdprof_fb.m
+++ b/deep_profiler/mdprof_fb.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2009 The University of Melbourne.
+% Copyright (C) 2009-2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -9,7 +9,7 @@
 % File: mdprof_fb.m.
 % Author: pbone.
 %
-% Deep Profiling feedback procuedres.  Each sub-module gathers some deep
+% Deep profiling feedback procedures. Each submodule gathers some deep
 % profiling feedback information for use by the compiler.
 %
 %-----------------------------------------------------------------------------%
diff --git a/deep_profiler/mdprof_feedback.m b/deep_profiler/mdprof_feedback.m
index 3209e9de9..213ba28c8 100644
--- a/deep_profiler/mdprof_feedback.m
+++ b/deep_profiler/mdprof_feedback.m
@@ -9,10 +9,11 @@
 % File: mdprof_feedback.m.
 % Author: tannier, pbone.
 %
-% This module contains the code for writing to a file the CSSs whose CSDs'
+% This module contains the code for writing to a file the CSSs whose CSD's
 % mean/median call sequence counts (own and desc) exceed the given threshold.
 %
-% The generated file will then be used by the compiler for implicit parallelism.
+% The generated file will then be used by the compiler for
+% implicit parallelism.
 %
 %-----------------------------------------------------------------------------%
 
@@ -181,24 +182,33 @@ create_feedback_report(feedback_data_candidate_parallel_conjunctions(
         ContextWakeupDelay, CliqueThreshold, CallSiteThreshold,
         ParalleliseDepConjs, BestParAlgorithm),
     best_par_algorithm_string(BestParAlgorithm, BestParAlgorithmStr),
-    ReportHeader = singleton(format("  Candidate Parallel Conjunctions:\n" ++
-            "    Desired parallelism: %f\n" ++
-            "    Intermodule var use: %s\n" ++
-            "    Sparking cost: %d\n" ++
-            "    Sparking delay: %d\n" ++
-            "    Future signal cost: %d\n" ++
-            "    Future wait cost: %d\n" ++
-            "    Context wakeup delay: %d\n" ++
-            "    Clique threshold: %d\n" ++
-            "    Call site threshold: %d\n" ++
-            "    Parallelise dependant conjunctions: %s\n" ++
-            "    BestParallelisationAlgorithm: %s\n" ++
-            "    Number of Parallel Conjunctions: %d\n" ++
-            "    Parallel Conjunctions:\n\n",
-        [f(DesiredParallelism), s(string(IntermoduleVarUse)), i(SparkingCost),
-         i(SparkingDelay), i(SignalCost), i(WaitCost), i(ContextWakeupDelay),
-         i(CliqueThreshold), i(CallSiteThreshold), s(ParalleliseDepConjsStr),
-         s(BestParAlgorithmStr), i(NumConjs)])),
+    ReportHeader = singleton(format(
+        "  Candidate Parallel Conjunctions:\n" ++
+        "    Desired parallelism: %f\n" ++
+        "    Intermodule var use: %s\n" ++
+        "    Sparking cost: %d\n" ++
+        "    Sparking delay: %d\n" ++
+        "    Future signal cost: %d\n" ++
+        "    Future wait cost: %d\n" ++
+        "    Context wakeup delay: %d\n" ++
+        "    Clique threshold: %d\n" ++
+        "    Call site threshold: %d\n" ++
+        "    Parallelise dependant conjunctions: %s\n" ++
+        "    BestParallelisationAlgorithm: %s\n" ++
+        "    Number of Parallel Conjunctions: %d\n" ++
+        "    Parallel Conjunctions:\n\n",
+        [f(DesiredParallelism),
+         s(string(IntermoduleVarUse)),
+         i(SparkingCost),
+         i(SparkingDelay),
+         i(SignalCost),
+         i(WaitCost),
+         i(ContextWakeupDelay),
+         i(CliqueThreshold),
+         i(CallSiteThreshold),
+         s(ParalleliseDepConjsStr),
+         s(BestParAlgorithmStr),
+         i(NumConjs)])),
     (
         ParalleliseDepConjs = parallelise_dep_conjs_overlap,
         ParalleliseDepConjsStr = "yes, use overlap calculation"
@@ -264,7 +274,7 @@ help_message =
                 call sequence counts.
     --implicit-parallelism-sparking-delay <value>
                 The time taken from the time a spark is created until the spark
-                is executed by another processor assuming that there is a free
+                is executed by another processor, assuming that there is a free
                 processor.
     --implicit-parallelism-future-signal-cost <value>
                 The cost of the signal() call for the producer of a shared
@@ -284,25 +294,25 @@ help_message =
                 The cost of a call site to be considered for parallelism
                 against another call site.
     --implicit-parallelism-dependant-conjunctions
-                Advise the compiler to parallelism dependant conjunctions.
+                Advise the compiler to parallelise dependant conjunctions.
                 This will become the default once the implementation is
                 complete.
-    --implicit-parallelism-dependant-conjunctions-algorithm <option>
+    --implicit-parallelism-dependant-conjunctions-algorithm <alg>
                 Choose the algorithm that is used to estimate the speedup for
-                dependant calculations.  The options are:
+                dependant calculations.  The algorithms are:
                     overlap: Compute the 'overlap' between dependant
                       conjunctions.
                     num_vars: Use the number of shared variables as a proxy for
                       the amount of overlap available.
                     naive: Ignore dependencies.
                 The default is overlap.
-    --implicit-parallelism-best-parallelisation-algorithm <option>
+    --implicit-parallelism-best-parallelisation-algorithm <algorithm>
                 Select which algorithm to use to find the best way to
-                parallelise a conjunction.  The options are:
+                parallelise a conjunction.  The algorithms are:
                     greedy: A greedy algorithm with a linear time complexity.
                     complete: A complete algorithm with a branch and bound
-                      search, this can be slow for problems larger then 50
-                      conjuncts, it has an exponential xomplexity.
+                      search. This can be slow for problems larger than 50
+                      conjuncts, since it has an exponential complexity.
                     complete-size(N): As above exept that it takes a single
                       parameter, N.  A conjunction has more than N conjuncts
                       then the greedy algorithm will be used.
@@ -422,25 +432,32 @@ short('r',  report).
 
 :- pred long(string::in, option::out) is semidet.
 
-long("help",                                help).
-long("verbosity",                           verbosity).
-long("version",                             version).
-long("debug-read-profile",                  debug_read_profile).
-long("report",                              report).
-
-long("calls-above-threshold-sorted",        calls_above_threshold_sorted).
+long("help",
+    help).
+long("verbosity",
+    verbosity).
+long("version",
+    version).
+long("debug-read-profile",
+    debug_read_profile).
+long("report",
+    report).
+long("calls-above-threshold-sorted",
+    calls_above_threshold_sorted).
 long("calls-above-threshold-sorted-measure",
     calls_above_threshold_sorted_measure).
-
-long("candidate-parallel-conjunctions",     candidate_parallel_conjunctions).
-
-long("implicit-parallelism",                implicit_parallelism).
-
-long("desired-parallelism",                 desired_parallelism).
+long("candidate-parallel-conjunctions",
+    candidate_parallel_conjunctions).
+long("implicit-parallelism",
+    implicit_parallelism).
+long("desired-parallelism",
+    desired_parallelism).
 long("implicit-parallelism-intermodule-var-use",
     implicit_parallelism_intermodule_var_use).
-long("implicit-parallelism-sparking-cost",  implicit_parallelism_sparking_cost).
-long("implicit-parallelism-sparking-delay", implicit_parallelism_sparking_delay).
+long("implicit-parallelism-sparking-cost",
+    implicit_parallelism_sparking_cost).
+long("implicit-parallelism-sparking-delay",
+    implicit_parallelism_sparking_delay).
 long("implicit-parallelism-future-signal-cost",
     implicit_parallelism_future_signal_cost).
 long("implicit-parallelism-future-wait-cost",
@@ -660,8 +677,7 @@ check_options(Options0, RequestedFeedbackInfo) :-
     parse_result(best_par_algorithm)::out) is det.
 
 parse_best_par_algorithm(String, Result) :-
-    promise_equivalent_solutions [Result]
-    (
+    promise_equivalent_solutions [Result] (
         parse(String, best_par_algorithm_parser, Result)
     ).
 
@@ -771,12 +787,6 @@ process_deep_to_feedback(RequestedFeedbackInfo, Deep, Messages, !Feedback) :-
         Messages = cord.empty
     ).
 
-%-----------------------------------------------------------------------------%
-
-:- func this_file = string.
-
-this_file = "mdprof_feedback: ".
-
 %-----------------------------------------------------------------------------%
 :- end_module mdprof_feedback.
 %-----------------------------------------------------------------------------%
diff --git a/deep_profiler/mdprof_test.m b/deep_profiler/mdprof_test.m
index 48b04f95e..465089ca7 100644
--- a/deep_profiler/mdprof_test.m
+++ b/deep_profiler/mdprof_test.m
@@ -10,6 +10,7 @@
 % Author: zs.
 %
 % This file contains a tool for testing the behavior of the deep profiler.
+%
 %-----------------------------------------------------------------------------%
 
 :- module mdprof_test.
@@ -206,7 +207,7 @@ write_help_message(ProgName) -->
         "--test      Test the deep profiler, generating all\n" ++
         "\t\t\tpossible web pages of the popular types.\n" ++
         "--verify-profile\n" ++
-        "\t\t\tVerify that <filename> is a well-formed deep profiling\n" ++ 
+        "\t\t\tVerify that <filename> is a well-formed deep profiling\n" ++
         "\t\t\tdata file.\n" ++
         "\n" ++
         "You may also specify the following options:.\n" ++
@@ -235,12 +236,13 @@ test_server(Pref, Deep, Options, !IO) :-
     % array.max(Deep ^ clique_members, NumCliques),
     % test_cliques(1, NumCliques, DirName, Pref, Deep, !IO),
     % test_procs(1, NumProcStatics, DirName, Pref, Deep, !IO).
-    
-    lookup_bool_option(Options, static_procrep_coverage, StaticProcrepCoverage),
+
+    lookup_bool_option(Options, static_procrep_coverage,
+        StaticProcrepCoverage),
     (
         StaticProcrepCoverage = yes,
         array.max(Deep ^ proc_statics, NumProcStatics),
-        test_procrep_static_coverages(1, NumProcStatics, Pref, Deep, Options, 
+        test_procrep_static_coverages(1, NumProcStatics, Pref, Deep, Options,
             !IO)
     ;
         StaticProcrepCoverage = no
@@ -294,7 +296,7 @@ test_procs(Cur, Max, Options, Pref, Deep, !IO) :-
 
 test_procrep_static_coverages(Cur, Max, Pref, Deep, Options, !IO) :-
     ( Cur =< Max ->
-        try_exec(deep_cmd_static_procrep_coverage(proc_static_ptr(Cur)), Pref, 
+        try_exec(deep_cmd_static_procrep_coverage(proc_static_ptr(Cur)), Pref,
             Deep, HTML, !IO),
         write_test_html(Options, "procrep_dynamic_coverage", Cur, HTML, !IO),
         test_procrep_static_coverages(Cur + 1, Max, Pref, Deep, Options, !IO)
@@ -315,7 +317,7 @@ test_procrep_dynamic_coverages(Cur, Max, Pref, Deep, Options, !IO) :-
         true
     ).
 
-:- pred test_recursion_types_histogram(preferences::in, deep::in, 
+:- pred test_recursion_types_histogram(preferences::in, deep::in,
     option_table::in, io::di, io::uo) is det.
 
 test_recursion_types_histogram(Pref, Deep, Options, !IO) :-
@@ -326,7 +328,7 @@ test_recursion_types_histogram(Pref, Deep, Options, !IO) :-
 
 :- func progrep_error = maybe_error(prog_rep).
 
-progrep_error = 
+progrep_error =
     error("No Program Representation available when using mdprof_test").
 
 :- pred write_test_html(option_table::in, string::in, int::in, string::in,
diff --git a/deep_profiler/measurement_units.m b/deep_profiler/measurement_units.m
index 79c9fb7e9..b20f1580e 100644
--- a/deep_profiler/measurement_units.m
+++ b/deep_profiler/measurement_units.m
@@ -116,11 +116,11 @@
 
 :- type probability.
 
-    % A certain thing,  A probability of 1.0
+    % A certain thing,  A probability of 1.0.
     %
 :- func certain = probability.
 
-    % An impossible thing.  A probability of 0.0
+    % An impossible thing.  A probability of 0.0.
     %
 :- func impossible = probability.
 
@@ -134,10 +134,12 @@
 :- func probability_to_float(probability) = float.
 
     % Combine probabilities.
+    %
 :- func or(probability, probability) = probability.
 :- func and(probability, probability) = probability.
 
     % The probability of the given probability not occuring.
+    %
 :- func not_probability(probability) = probability.
 
 %-----------------------------------------------------------------------------%
@@ -205,7 +207,7 @@ compare_memory(MemoryA, MemoryB, Result) :-
 
 %-----------------------------------------------------------------------------%
 %
-% Percent
+% Percentages.
 %
 
 :- type percent
@@ -281,7 +283,7 @@ format_time(time_sec(F)) = String :-
 
 %-----------------------------------------------------------------------------%
 %
-% Probability
+% Probabilities.
 %
 
 :- type probability == float.
@@ -297,7 +299,7 @@ probable(Prob) = Prob :-
     ->
         true
     ;
-        error(format("Probability %f out of range 0.0 to 1.0 inclusive", 
+        error(format("Probability %f out of range 0.0 to 1.0 inclusive",
             [f(Prob)]))
     ).
 
diff --git a/deep_profiler/measurements.m b/deep_profiler/measurements.m
index ba8a57c59..0180557f8 100644
--- a/deep_profiler/measurements.m
+++ b/deep_profiler/measurements.m
@@ -763,7 +763,7 @@ add_goal_costs_seq(non_trivial_goal(CostA, CallsA),
         Calls = 0,
         CostTotal \= 0.0
     ->
-        error(this_file ++ "add_goal_costs_seq/2: Calls = 0, Cost \\= 0")
+        unexpected($module, $pred, "Calls = 0, Cost \\= 0")
     ;
         true
     ).
@@ -777,7 +777,7 @@ add_goal_costs_branch(TotalCalls, A, B) = R :-
             CallsA = 0,
             (
                 B = dead_goal,
-                error("TotalCalls \\= 0 for a dead goal")
+                unexpected($module, $pred, "TotalCalls \\= 0 for a dead goal")
             ;
                 B = trivial_goal(CallsB),
                 R = trivial_goal(TotalCalls)
@@ -820,8 +820,11 @@ add_goal_costs_branch(TotalCalls, A, B) = R :-
 
 check_total_calls(CallsA, CallsB, TotalCalls) :-
     Calls = CallsA + CallsB,
-    require(unify(Calls, TotalCalls),
-        this_file ++ "TotalCalls \\= CallsA + CallsB").
+    ( unify(Calls, TotalCalls) ->
+        true
+    ;
+        unexpected($module, $pred, "TotalCalls \\= CallsA + CallsB")
+    ).
 
 goal_cost_get_percall(dead_goal) = 0.0.
 goal_cost_get_percall(trivial_goal(_)) = 0.0.
@@ -907,7 +910,7 @@ add_coverage_arrays(NewArray, yes(!.Array), yes(!:Array)) :-
                 set(A0, Index, Value + E, A)
             ), NewArray, !Array)
     ;
-        error(this_file ++ "Arrays' bounds do not match")
+        unexpected($module, $pred, "arrays' bounds do not match")
     ).
 
 array_to_static_coverage(Array, yes(Array)).
@@ -941,7 +944,7 @@ no_parallelism = parallelism_amount(1.0).
 
 some_parallelism(Num) = parallelism_amount(Num) :-
     ( Num < 1.0 ->
-        error(this_file ++ "some_parallelism/1+1: " ++
+        unexpected($module, $pred,
             "Parallelism amount cannot ever be less than 1.0")
     ;
         true
@@ -978,10 +981,10 @@ exceeded_desired_parallelism(DesiredParallelism, Parallelism) :-
 
                 pemi_context_wakeup_delay   :: float,
 
+                % If there are no internal conjuncts then the parallel
+                % conjunction is empty.
                 pemi_internal               ::
                         maybe(parallel_exec_metrics_internal)
-                    % If there are no internal conjuncts then the parallel
-                    % conjunction is empty.
             ).
 
 :- type parallel_exec_metrics_internal
@@ -990,27 +993,27 @@ exceeded_desired_parallelism(DesiredParallelism, Parallelism) :-
                 pemi_time_par               :: float
             )
     ;       pem_additional(
+                % The time of the left conjunct (that may be a conjunction).
                 pemi_time_left              :: parallel_exec_metrics_internal,
-                    % The time of the left conjunct (that may be a conjunction),
 
+                % The additional cost of calling signal within the left
+                % conjunct.
+                % NOTE: Note that this should be added to each of the
+                % individual conjuncts _where_ they call signal but thta is
+                % more difficult and may not be required.  We may visit it
+                % in the future.
                 pemi_time_left_signals      :: float,
-                    % The additional cost of calling signal within the left
-                    % conjunct.
-                    % NOTE: Note that this should be added to each of the
-                    % individual conjuncts _where_ they call signal but thta is
-                    % more difficult and may not be required.  We may visit it
-                    % in the future.
 
+                % The time of the right conjunct if it is running after
+                % the left in normal sequential execution.
                 pemi_time_right_seq         :: float,
-                    % The time of the right conjunct if it is running after
-                    % the left in normal sequential execution.
 
+                % The time of the right conjunct if it is running in
+                % parallel with the left conjunct.  It may have to stop and
+                % wait for variables to be produced; therefore this time is
+                % different to time_right_seq.  This time also includes
+                % parallel execution overheads and delays.
                 pemi_time_right_par         :: float
-                    % The time of the right conjunct if it is running in
-                    % parallel with the left conjunct.  It may have to stop and
-                    % wait for variables to be produced; therefore this time is
-                    % different to time_right_seq.  This time also includes
-                    % parallel execution overheads and delays.
             ).
 
 init_parallel_exec_metrics_incomplete(Metrics0, TimeSignals, TimeBSeq,
@@ -1022,8 +1025,11 @@ init_parallel_exec_metrics_incomplete(Metrics0, TimeSignals, TimeBSeq,
     ;
         MaybeInternal0 = no,
         Internal = pem_left_most(TimeBSeq, TimeBPar),
-        require(unify(TimeSignals, 0.0),
-            this_file ++ "TimeSignal != 0")
+        ( unify(TimeSignals, 0.0) ->
+            true
+        ;
+            unexpected($module, $pred, "TimeSignal != 0")
+        )
     ),
     Metrics = Metrics0 ^ pemi_internal := yes(Internal).
 
@@ -1039,7 +1045,7 @@ finalise_parallel_exec_metrics(IncompleteMetrics) = Metrics :-
         MaybeInternal = yes(Internal)
     ;
         MaybeInternal = no,
-        error(this_file ++ "Cannot finalise empty parallel metrics.")
+        unexpected($module, $pred, "cannot finalise empty parallel metrics")
     ),
     BeforeAndAfterTime = TimeBefore + TimeAfter,
 
@@ -1154,12 +1160,6 @@ weighted_average(Weights, Values, Average) :-
         Average = Total / TotalWeight
     ).
 
-%----------------------------------------------------------------------------%
-
-:- func this_file = string.
-
-this_file = "measurements.m: ".
-
 %----------------------------------------------------------------------------%
 :- end_module measurements.
 %----------------------------------------------------------------------------%
diff --git a/deep_profiler/message.m b/deep_profiler/message.m
index 00ac4b0c7..fe71018d8 100644
--- a/deep_profiler/message.m
+++ b/deep_profiler/message.m
@@ -28,15 +28,15 @@
 :- import_module string.
 
 %-----------------------------------------------------------------------------%
-    
+
 	% A message to be displayed to the user.
     %
-:- type message 
+:- type message
     --->    message(
                 message_location    :: program_location,
-                message_type        :: message_type 
+                message_type        :: message_type
             ).
-    
+
     % The 'importance' of a message,  Debug messages are not covered here since
     % they should be implemented via trace goals. neither are critical messages
     % since we use exceptions in that case.
@@ -65,100 +65,91 @@
     %
     % Pretty-print a location to a cord of strings.
     %
-:- pred location_to_string(int::in, program_location::in, cord(string)::out) 
+:- pred location_to_string(int::in, program_location::in, cord(string)::out)
     is det.
 
 :- pred append_message(program_location::in, message_type::in,
     cord(message)::in, cord(message)::out) is det.
 
 %-----------------------------------------------------------------------------%
-    
+
 	% A type of message, values of type 'message' are instances of values of
     % type 'message_type'.
     %
 :- type message_type
 
-                % A candidate parallel conjunction has been found.
     --->    info_found_candidate_conjunction
+            % A candidate parallel conjunction has been found.
 
-                % There are a number of conjuncts containing calls above the
-                % configured call site threshold, we're considering them for
-                % parallelisation against one another.
-                %
     ;       info_found_conjs_above_callsite_threshold(int)
+            % There are a number of conjuncts containing calls above the
+            % configured call site threshold, we're considering them for
+            % parallelisation against one another.
 
-                % The conjunction being consdered for parallelisation had to be
-                % split into several 'partitions' because it contains some non
-                % atomic goals, this can limit the amount of parallelism
-                % available.
     ;       info_split_conjunction_into_partitions(int)
+            % The conjunction being consdered for parallelisation had to be
+            % split into several 'partitions' because it contains some non
+            % atomic goals, this can limit the amount of parallelism
+            % available.
 
-                % There are N conjunctions whose speedup due to parallelisation
-                % is positive.
     ;       info_found_n_conjunctions_with_positive_speedup(int)
+            % There are N conjunctions whose speedup due to parallelisation
+            % is positive.
 
-                % This occurs when a variable is instantiated twice in a
-                % procedure body (different instantiation states are used).  We
-                % don't bother parallelising such procedures.
-                %
     ;       notice_duplicate_instantiation(
+                % This occurs when a variable is instantiated twice in a
+                % procedure body (different instantiation states are used).
+                % We don't bother parallelising such procedures.
+                %
+                % The number of conjunctions that could have been
+                % parallelised.
                 int
-                    % The number of conjunctions that could have been
-                    % parallelised.
             )
 
-                % A pair of calls that could be parallelised have many
-                % dependant variables.  We don't yet calculate the speedup in
-                % these situations.
-                %
     ;       notice_callpair_has_more_than_one_dependant_var
+            % A pair of calls that could be parallelised have many
+            % dependent variables. We don't yet calculate the speedup in
+            % these situations.
 
-                % A partition does not enough enough costly calls (>1) and
-                % could not be parallelised, we could have parallelised them if
-                % we could parallelise over non-atomic code.
-                % 
-                % The parameters are the partition number and the number of
-                % costly calls found.
-                %
     ;       notice_partition_does_not_have_costly_calls(int, int)
+            % A partition does not enough enough costly calls (>1) and
+            % could not be parallelised, we could have parallelised them
+            % if we could parallelise over non-atomic code.
+            %
+            % The parameters are the partition number and the number of
+            % costly calls found.
 
-                % The candidate conjunction has goals that arn't
-                % determinstic or cc_multi amongst the costly calls.
-                %
     ;       notice_candidate_conjunction_not_det(detism_rep)
+            % The candidate conjunction has goals that are not
+            % determinstic or cc_multi amongst the costly calls.
 
-                % Couldn't find the proc defn in the progrep data, maybe the
-                % procedure is built-in.
-                %
     ;       warning_cannot_lookup_proc_defn
+            % Couldn't find the proc defn in the progrep data, maybe the
+            % procedure is built-in.
 
-                % Couldn't compute the coverage annotation for a procedure
-                % representation.  A fallback method will be used but whithout
-                % this information it may be less accurate.
-                %
     ;       warning_cannot_compute_procrep_coverage_fallback(string)
+            % Couldn't compute the coverage annotation for a procedure
+            % representation. A fallback method will be used but without
+            % this information it may be less accurate.
 
-                % Couldn't compute the cost of recursive calls.
-                %
-                % The parameter contains extra information about this error.
-                %
     ;       warning_cannot_compute_cost_of_recursive_calls(string)
-            
-                % Couldn't compute the time at which a variable is produced or
-                % consumed.
-                %
-                % The parameter contains extra information about this error.
+            % Couldn't compute the cost of recursive calls.
+            %
+            % The parameter contains extra information about this error.
+
     ;       warning_cannot_compute_first_use_time(string)
+            % Couldn't compute the time at which a variable is produced
+            % or consumed.
+            %
+            % The parameter contains extra information about this error.
 
-                % We don't yet handle clique_proc_reports with multiple proc
-                % dynamics.
-                %
     ;       error_extra_proc_dynamics_in_clique_proc
+            % We don't yet handle clique_proc_reports with multiple proc
+            % dynamics.
 
-                % An error in the generation of a coverage_procrep report.
-                %
     ;       error_coverage_procrep_error(string)
-    
+            % An error in the generation of a coverage_procrep report.
+
     ;       error_exception_thrown(string).
 
 %-----------------------------------------------------------------------------%
@@ -180,10 +171,10 @@
 :- func indent_size(int) = int.
 
 %-----------------------------------------------------------------------------%
-    
+
     % Write out messages.
     %
-:- pred write_out_messages(io.output_stream::in, cord(message)::in, 
+:- pred write_out_messages(io.output_stream::in, cord(message)::in,
     io::di, io::uo) is det.
 
     % Set the verbosity level to use above.  Higher levels print out more
@@ -223,13 +214,13 @@ message_to_string(message(Location, MessageType), String) :-
 
 location_to_string(Level, proc(ProcLabel), String) :-
     print_proc_label_to_string(ProcLabel, ProcLabelString),
-    String = indent(Level) ++ singleton("Proc: ") ++ 
+    String = indent(Level) ++ singleton("Proc: ") ++
         singleton(ProcLabelString) ++ singleton("\n").
 location_to_string(Level, goal(ProcLabel, GoalPath), String) :-
     ( empty_goal_path(GoalPath) ->
         GoalPathString = singleton("Root goal")
     ;
-        GoalPathString = 
+        GoalPathString =
             singleton("Goal: ") ++ singleton(goal_path_to_string(GoalPath))
     ),
     location_to_string(Level, proc(ProcLabel), FirstLine),
@@ -286,11 +277,11 @@ message_type_to_level(notice_candidate_conjunction_not_det(_)) =
 message_type_to_level(warning_cannot_lookup_proc_defn) = message_warning.
 message_type_to_level(warning_cannot_compute_procrep_coverage_fallback(_)) =
     message_warning.
-message_type_to_level(warning_cannot_compute_cost_of_recursive_calls(_)) = 
+message_type_to_level(warning_cannot_compute_cost_of_recursive_calls(_)) =
     message_warning.
-message_type_to_level(warning_cannot_compute_first_use_time(_)) = 
+message_type_to_level(warning_cannot_compute_first_use_time(_)) =
     message_warning.
-message_type_to_level(error_extra_proc_dynamics_in_clique_proc) = 
+message_type_to_level(error_extra_proc_dynamics_in_clique_proc) =
     message_error.
 message_type_to_level(error_coverage_procrep_error(_)) =
     message_error.
@@ -302,7 +293,7 @@ message_type_to_level(error_exception_thrown(_)) = message_error.
 
 message_type_to_string(MessageType) = Cord :-
     (
-        MessageType = info_found_candidate_conjunction, 
+        MessageType = info_found_candidate_conjunction,
         String = "Found candidate conjunction"
     ;
         (
@@ -314,24 +305,24 @@ message_type_to_string(MessageType) = Cord :-
                 ++ " to parallelisation"
         ;
             MessageType = info_split_conjunction_into_partitions(Num),
-            MessageStr = "Split conjunction into %d partitions, this may reduce"
-                ++ " parallelism"
+            MessageStr = "Split conjunction into %d partitions, "
+                ++ "this may reduce parallelism"
         ),
         string.format(MessageStr, [i(Num)], String)
     ;
-        MessageType = notice_duplicate_instantiation(CandidateConjuncts), 
+        MessageType = notice_duplicate_instantiation(CandidateConjuncts),
         string.format(
             "%d conjunctions not parallelised: Seen duplicate instantiations",
             [i(CandidateConjuncts)], String)
     ;
         MessageType = notice_callpair_has_more_than_one_dependant_var,
-        String = "Parallelising call pairs that have more than one dependant"
-            ++ " variable is not yet supported."
+        String = "Parallelising call pairs that have more than one "
+            ++ "dependent variable is not yet supported."
     ;
         MessageType = notice_partition_does_not_have_costly_calls(PartNum,
             NumCalls),
         string.format("Partition %d has only %d costly calls and cannot be"
-                ++ " parallelised", 
+                ++ " parallelised",
             [i(PartNum), i(NumCalls)], String)
     ;
         MessageType = notice_candidate_conjunction_not_det(Detism),
@@ -344,10 +335,10 @@ message_type_to_string(MessageType) = Cord :-
             ++ " built-in"
     ;
         MessageType = warning_cannot_compute_procrep_coverage_fallback(Error),
-        String = "Cannot compute procrep coverage annotation: " ++ Error 
+        String = "Cannot compute procrep coverage annotation: " ++ Error
             ++ "\n  falling back to some other method"
     ;
-        MessageType = error_extra_proc_dynamics_in_clique_proc, 
+        MessageType = error_extra_proc_dynamics_in_clique_proc,
         String = "extra proc dynamnics for a clique proc are not currenty"
             ++ " handled."
     ;
@@ -362,10 +353,10 @@ message_type_to_string(MessageType) = Cord :-
                 warning_cannot_compute_cost_of_recursive_calls(ErrorStr),
             Template = "Cannot compute cost of recursive calls: %s"
         ;
-            MessageType = 
+            MessageType =
                 warning_cannot_compute_first_use_time(ErrorStr),
-            Template = "Cannot compute the production or consumption time of a"
-                ++ " variable: %s"
+            Template = "Cannot compute the production or consumption time "
+                ++ "of a variable: %s"
         ),
         string.format(Template, [s(ErrorStr)], String)
     ),
@@ -377,7 +368,7 @@ indent(N) = Indent :-
     ( N < 0 ->
         error("automatic_parallelism: Negative indent")
     ; N = 0 ->
-        Indent = empty 
+        Indent = empty
     ;
         Indent = snoc(indent(N - 1), "  ")
     ).
@@ -390,13 +381,13 @@ indent_size(N) = 2 * N.
 
 %----------------------------------------------------------------------------%
 
-:- mutable(verbosity_level_mut, int, default_verbosity_level, ground, 
+:- mutable(verbosity_level_mut, int, default_verbosity_level, ground,
     [attach_to_io_state, untrailed]).
 
 write_out_messages(Stream, Messages, !IO) :-
     cord.foldl_pred(write_out_message(Stream), Messages, !IO).
 
-:- pred write_out_message(output_stream::in, message::in, io::di, io::uo) 
+:- pred write_out_message(output_stream::in, message::in, io::di, io::uo)
     is det.
 
 write_out_message(Stream, Message, !IO) :-
diff --git a/deep_profiler/old_query.m b/deep_profiler/old_query.m
index d9a958bbe..90c256fc7 100644
--- a/deep_profiler/old_query.m
+++ b/deep_profiler/old_query.m
@@ -30,7 +30,7 @@
     % Old deep profiler cgi code.  This should remain supported until all cmds
     % have been updated to use the data structures in report.m.
     %
-:- pred old_exec(cmd::in, preferences::in, deep::in, string::out, 
+:- pred old_exec(cmd::in, preferences::in, deep::in, string::out,
     io::di, io::uo) is det.
 
 %-----------------------------------------------------------------------------%
@@ -147,7 +147,7 @@ old_exec(Cmd, _, _, HTML, !IO) :-
     ; Cmd = deep_cmd_clique_recursive_costs(_)
     ; Cmd = deep_cmd_recursion_types_frequency
     ),
-    format("old_query.m: %s is unsupported by old_exec\n", [s(string(Cmd))], 
+    format("old_query.m: %s is unsupported by old_exec\n", [s(string(Cmd))],
         HTML).
 
 %-----------------------------------------------------------------------------%
diff --git a/deep_profiler/profile.m b/deep_profiler/profile.m
index 591b52bee..abd30edf4 100644
--- a/deep_profiler/profile.m
+++ b/deep_profiler/profile.m
@@ -205,28 +205,28 @@
     --->    proc_static(
                 % procedure ID
                 ps_id                       :: string_proc_label,
-                
+
                 % declaring module
                 ps_decl_module              :: string,
-                
+
                 % unqualified refined id
                 ps_uq_refined_id            :: string,
-                
+
                 % qualified refined id
                 ps_q_refined_id             :: string,
-                
+
                 % raw procedure id
                 ps_raw_id                   :: string,
-                
+
                 % file name of proc
                 ps_file_name                :: string,
-                
+
                 % line number of proc
                 ps_line_number              :: int,
-                
+
                 % is in interface?
                 ps_in_interface             :: bool,
-                
+
                 ps_sites                    :: array(call_site_static_ptr),
                 ps_coverage_point_infos     :: array(coverage_point_info),
                 ps_maybe_coverage_points    :: maybe(array(int)),
@@ -462,7 +462,7 @@
     array(inherit_prof_info)::array_di, array(inherit_prof_info)::array_uo)
     is det.
 :- pred update_ps_coverage(proc_static_ptr::in, static_coverage_info::in,
-    array(static_coverage_info)::array_di, 
+    array(static_coverage_info)::array_di,
     array(static_coverage_info)::array_uo) is det.
 
 :- pred deep_update_csd_desc(call_site_dynamic_ptr::in, inherit_prof_info::in,
@@ -1055,7 +1055,7 @@ root_desc_info(Deep) = RootDesc :-
 
 root_own_info(Deep) = RootOwn :-
     deep_lookup_pd_own(Deep, Deep ^ root, RootOwn).
-    
+
 %-----------------------------------------------------------------------------%
 
 deep_get_progrep_det(Deep, ProgRep) :-
@@ -1064,7 +1064,7 @@ deep_get_progrep_det(Deep, ProgRep) :-
         MaybeProgRep = ok(ProgRep)
     ;
         MaybeProgRep = error(Error),
-        error(this_file ++ Error)
+        unexpected($module, $pred, Error)
     ).
 
 deep_get_maybe_progrep(Deep, MaybeProgRep) :-
@@ -1082,12 +1082,6 @@ deep_get_maybe_progrep(Deep, MaybeProgRep) :-
         MaybeProgRep = ok(ProgRep)
     ).
 
-%-----------------------------------------------------------------------------%
-
-:- func this_file = string.
-
-this_file = "profile.m: ".
-
 %-----------------------------------------------------------------------------%
 :- end_module profile.
 %-----------------------------------------------------------------------------%
diff --git a/deep_profiler/program_representation_utils.m b/deep_profiler/program_representation_utils.m
index 64e05a0f6..7f55833cd 100644
--- a/deep_profiler/program_representation_utils.m
+++ b/deep_profiler/program_representation_utils.m
@@ -953,9 +953,3 @@ atomic_goal_is_call(AtomicGoal, IsCall) :-
 
 %----------------------------------------------------------------------------%
 
-:- func this_file = string.
-
-this_file = "program_representation_utils: ".
-
-%----------------------------------------------------------------------------%
-
diff --git a/deep_profiler/query.m b/deep_profiler/query.m
index eeaba9fd5..5db83512f 100644
--- a/deep_profiler/query.m
+++ b/deep_profiler/query.m
@@ -147,7 +147,7 @@
                 cmd_dcl_id                      :: clique_ptr
             )
     ;       deep_cmd_call_site_dynamic_var_use(
-                cmd_csdvu_id                    :: call_site_dynamic_ptr 
+                cmd_csdvu_id                    :: call_site_dynamic_ptr
             ).
 
 :- type caller_groups
@@ -201,7 +201,7 @@
 
                 % The max number of proc statics to display for each recursion
                 % type group in the recursion type frequency report.
-                pref_proc_statics_per_rec_type 
+                pref_proc_statics_per_rec_type
                                     :: int,
 
                 % Whether pages should summarize at higher order call sites.
@@ -489,7 +489,7 @@ new_exec(Cmd, Prefs, Deep, HTMLStr, !IO) :-
 
 slow_cmd(deep_cmd_recursion_types_frequency).
 
-:- pragma memo(create_and_memoize_report(in, in, out), 
+:- pragma memo(create_and_memoize_report(in, in, out),
     [specified([value, addr, output])]).
 :- pred create_and_memoize_report(cmd::in, deep::in, deep_report::out) is det.
 
@@ -594,7 +594,7 @@ limit_separator_char = ('-').
 cmd_to_string(Cmd) = CmdStr :-
     (
         Cmd = deep_cmd_quit,
-        CmdStr = cmd_str_quit 
+        CmdStr = cmd_str_quit
     ;
         Cmd = deep_cmd_restart,
         CmdStr = cmd_str_restart
@@ -796,7 +796,7 @@ string_to_maybe_cmd(QueryString) = MaybeCmd :-
         Cmd = deep_cmd_proc(PSPtr),
         MaybeCmd = yes(Cmd)
     ;
-        Pieces = [cmd_str_proc_callers, PSIStr, GroupCallersStr, BunchNumStr, 
+        Pieces = [cmd_str_proc_callers, PSIStr, GroupCallersStr, BunchNumStr,
             CallersPerBunchStr, ContourStr],
         string.to_int(PSIStr, PSI),
         string_to_caller_groups(GroupCallersStr, GroupCallers),
@@ -824,7 +824,7 @@ string_to_maybe_cmd(QueryString) = MaybeCmd :-
         Cmd = deep_cmd_module_getter_setters(ModuleName),
         MaybeCmd = yes(Cmd)
     ;
-        Pieces = [cmd_str_top_procs, LimitStr, CostKindStr, InclDescStr, 
+        Pieces = [cmd_str_top_procs, LimitStr, CostKindStr, InclDescStr,
             ScopeStr],
         string_to_limit(LimitStr, Limit),
         string_to_cost_kind(CostKindStr, CostKind),
@@ -916,7 +916,7 @@ string_to_maybe_pref(QueryString) = MaybePreferences :-
     split(QueryString, pref_separator_char, Pieces),
     (
         Pieces = [FieldsStr, BoxStr, ColourStr,
-            MaybeAncestorLimitStr, ProcStaticsPerRecTypeLimitStr, 
+            MaybeAncestorLimitStr, ProcStaticsPerRecTypeLimitStr,
             SummarizeHoCallSitesStr, OrderStr, ContourStr, TimeStr,
             ModuleQualStr, InactiveItemsStr, DeveloperModeStr],
         string_to_fields(FieldsStr, Fields),
@@ -948,7 +948,7 @@ string_to_maybe_pref(QueryString) = MaybePreferences :-
     ).
 
 query_to_string(DeepQuery) = String :-
-    DeepQuery = deep_query(yes(Cmd), DeepFileName, MaybePreferences), 
+    DeepQuery = deep_query(yes(Cmd), DeepFileName, MaybePreferences),
     (
         MaybePreferences = yes(Preferences),
         PreferencesString = preferences_to_string(Preferences)
@@ -981,8 +981,8 @@ string_to_maybe_query(String) = MaybeDeepQuery :-
             MaybePrefStr = no,
             MaybePreferences = no
         ),
-        MaybeDeepQuery = 
-            yes(deep_query(MaybeCmd, DeepFileName, MaybePreferences)) 
+        MaybeDeepQuery =
+            yes(deep_query(MaybeCmd, DeepFileName, MaybePreferences))
     ;
         MaybeDeepQuery = no
     ).
@@ -1363,7 +1363,7 @@ cmd_str_clique = "clique".
 
 :- func cmd_str_clique_recursive_costs = string.
 cmd_str_clique_recursive_costs = "clique_rc".
-        
+
 :- func cmd_str_recursion_types_frequency = string.
 cmd_str_recursion_types_frequency = "recursion_type_freq".
 
diff --git a/deep_profiler/read_profile.m b/deep_profiler/read_profile.m
index 24a9075f9..e5aa3ce4e 100644
--- a/deep_profiler/read_profile.m
+++ b/deep_profiler/read_profile.m
@@ -1560,11 +1560,5 @@ make_dummy_psptr = proc_static_ptr(-1).
     }
 ").
 
-%------------------------------------------------------------------------------%
-
-:- func this_file = string.
-
-this_file = "read_profile.m: ".
-
 %------------------------------------------------------------------------------%
 %------------------------------------------------------------------------------%
diff --git a/deep_profiler/recursion_patterns.m b/deep_profiler/recursion_patterns.m
index 015640988..2317b5db1 100644
--- a/deep_profiler/recursion_patterns.m
+++ b/deep_profiler/recursion_patterns.m
@@ -22,13 +22,13 @@
 :- import_module profile.
 
 :- import_module maybe.
-            
+
 %----------------------------------------------------------------------------%
 
 :- pred create_clique_recursion_costs_report(deep::in, clique_ptr::in,
     maybe_error(clique_recursion_report)::out) is det.
 
-:- pred create_recursion_types_frequency_report(deep::in, 
+:- pred create_recursion_types_frequency_report(deep::in,
     maybe_error(recursion_types_frequency_report)::out) is det.
 
 %----------------------------------------------------------------------------%
@@ -75,7 +75,7 @@
 
 create_clique_recursion_costs_report(Deep, CliquePtr,
         MaybeCliqueRecursionReport) :-
-    find_clique_first_and_other_procs(Deep, CliquePtr, MaybeFirstPDPtr, 
+    find_clique_first_and_other_procs(Deep, CliquePtr, MaybeFirstPDPtr,
         OtherPDPtrs),
     deep_lookup_clique_parents(Deep, CliquePtr, ParentCallPtr),
     ( valid_call_site_dynamic_ptr(Deep, ParentCallPtr) ->
@@ -91,7 +91,7 @@ create_clique_recursion_costs_report(Deep, CliquePtr,
         (
             OtherPDPtrs = [],
             % Exaclty one procedure
-            proc_get_recursion_type(Deep, CliquePtr, FirstPDPtr, ParentCalls, 
+            proc_get_recursion_type(Deep, CliquePtr, FirstPDPtr, ParentCalls,
                 MaybeRecursionType)
         ;
             OtherPDPtrs = [_ | _],
@@ -113,7 +113,7 @@ create_clique_recursion_costs_report(Deep, CliquePtr,
             "This clique doesn't appear to have an entry procedure")
     ).
 
-:- pred proc_get_recursion_type(deep::in, clique_ptr::in, 
+:- pred proc_get_recursion_type(deep::in, clique_ptr::in,
     proc_dynamic_ptr::in, int::in, maybe_error(recursion_type)::out) is det.
 
 proc_get_recursion_type(Deep, ThisClique, PDPtr, ParentCalls,
@@ -123,10 +123,10 @@ proc_get_recursion_type(Deep, ThisClique, PDPtr, ParentCalls,
     create_dynamic_procrep_coverage_report(Deep, PDPtr, MaybeCoverageReport),
     (
         MaybeCoverageReport = ok(CoverageReport),
-        ProcRep = CoverageReport ^ prci_proc_rep, 
+        ProcRep = CoverageReport ^ prci_proc_rep,
         Goal = ProcRep ^ pr_defn ^ pdr_goal,
         proc_dynamic_paired_call_site_slots(Deep, PDPtr, Slots),
-        foldl(build_call_site_cost_and_callee_map(Deep), 
+        foldl(build_call_site_cost_and_callee_map(Deep),
             Slots, map.init, CallSitesMap),
         goal_recursion_data(ThisClique, CallSitesMap, empty_goal_path,
             Goal, RecursionData),
@@ -134,14 +134,14 @@ proc_get_recursion_type(Deep, ThisClique, PDPtr, ParentCalls,
             RecursionData, RecursionType),
         MaybeRecursionType = ok(RecursionType)
     ;
-        MaybeCoverageReport = error(Error), 
+        MaybeCoverageReport = error(Error),
         MaybeRecursionType = error(Error)
     ).
 
 :- pred recursion_data_to_recursion_type(int::in, int::in, recursion_data::in,
     recursion_type::out) is det.
 
-recursion_data_to_recursion_type(ParentCallsI, TotalCallsI, 
+recursion_data_to_recursion_type(ParentCallsI, TotalCallsI,
         recursion_data(Levels, Maximum, Errors), Type) :-
     ParentCalls = float(ParentCallsI),
     TotalCalls = float(TotalCallsI),
@@ -154,10 +154,10 @@ recursion_data_to_recursion_type(ParentCallsI, TotalCallsI,
         BaseCount = 0,
         BaseProb = impossible
     ),
-    BaseLevel = recursion_level_report(0, BaseCount, BaseProb, BaseCost, 0.0), 
+    BaseLevel = recursion_level_report(0, BaseCount, BaseProb, BaseCost, 0.0),
     ( empty(Errors) ->
         ( Maximum < 0 ->
-            error(this_file ++ "negative number of recursive calls")
+            unexpected($module, $pred, "negative number of recursive calls")
         ; Maximum = 0 ->
             Type = rt_not_recursive
         ; Maximum = 1 ->
@@ -167,8 +167,8 @@ recursion_data_to_recursion_type(ParentCallsI, TotalCallsI,
                 RecLevel = recursion_level_report(1, round_to_int(RecCountF),
                     RecProb, RecCost, 1.0)
             ;
-                error(format("%smaximum level %d not found", 
-                    [s(this_file), i(1)]))
+                string.format("maximum level %d not found", [i(1)], Msg),
+                unexpected($module, $pred, Msg)
             ),
             AvgMaxDepth = TotalCalls / ParentCalls,
             AvgRecCost = single_rec_average_recursion_cost(BaseCost, RecCost,
@@ -186,8 +186,8 @@ recursion_data_to_recursion_type(ParentCallsI, TotalCallsI,
                 RecLevel = recursion_level_report(2, round_to_int(RecCountF),
                     RecProb, RecCost, RecCountF*2.0)
             ;
-                error(format("%smaximum level %d not found", 
-                    [s(this_file), i(1)]))
+                string.format("maximum level %d not found", [i(1)], Msg),
+                unexpected($module, $pred, Msg)
             ),
             Type = rt_divide_and_conquer(BaseLevel, RecLevel)
         ;
@@ -201,10 +201,10 @@ recursion_data_to_recursion_type(ParentCallsI, TotalCallsI,
 % A procedure that is never called never recurses.
 recursion_data_to_recursion_type(_, _, proc_dead_code, rt_not_recursive).
 
-:- pred recursion_level_report(float::in, pair(int, recursion_level)::in, 
+:- pred recursion_level_report(float::in, pair(int, recursion_level)::in,
     recursion_level_report::out) is det.
 
-recursion_level_report(TotalCalls, Level - recursion_level(NonRecCost, Prob), 
+recursion_level_report(TotalCalls, Level - recursion_level(NonRecCost, Prob),
         recursion_level_report(Level, Calls, Prob, NonRecCost, CostExChild)) :-
     CallsF = probability_to_float(Prob) * TotalCalls,
     Calls = round_to_int(CallsF),
@@ -226,10 +226,9 @@ recursion_level_report(TotalCalls, Level - recursion_level(NonRecCost, Prob),
     %
 :- func single_rec_recursion_cost(float, float, int) = float.
 
-single_rec_recursion_cost(BaseCost, RecCost, LevelI) = 
-        BaseCost + (Level * (RecCost + 1.0)) :-
-    Level = float(LevelI).
-    
+single_rec_recursion_cost(BaseCost, RecCost, LevelI) = Cost :-
+    Cost = BaseCost + (float(LevelI) * (RecCost + 1.0)).
+
     % This formula is derived as follows.
     %
     % It's the average (sum of all recursion levels divided by number of
@@ -238,7 +237,7 @@ single_rec_recursion_cost(BaseCost, RecCost, LevelI) =
     %   Sum l in 0..MaxLevel ( Base + l * Rec ) / ( MaxLevel + 1 )
     %
     % Factor out the cost of the base case and start the sum from level 1 in
-    % the recursive case. 
+    % the recursive case.
     %
     %   ( Base(MaxLevel + 1) + Sum l in 1..MaxLevel ( l * Rec ) ) /
     %     ( MaxLevel + 1 )
@@ -253,9 +252,9 @@ single_rec_recursion_cost(BaseCost, RecCost, LevelI) =
     %
 :- func single_rec_average_recursion_cost(float, float, float) = float.
 
-single_rec_average_recursion_cost(BaseCost, RecCost, AvgMaxDepth) = 
-        BaseCost + ( (Sum) / (AvgMaxDepth + 1.0) ) :-
-    Sum = 0.5 * RecCost * ((AvgMaxDepth * AvgMaxDepth) + AvgMaxDepth).
+single_rec_average_recursion_cost(BaseCost, RecCost, AvgMaxDepth) = Cost :-
+    Sum = 0.5 * RecCost * ((AvgMaxDepth * AvgMaxDepth) + AvgMaxDepth),
+    Cost = BaseCost + ((Sum) / (AvgMaxDepth + 1.0)).
 
 %----------------------------------------------------------------------------%
 
@@ -265,7 +264,7 @@ single_rec_average_recursion_cost(BaseCost, RecCost, AvgMaxDepth) =
                 rd_maximum              :: int,
                 rd_errors               :: set(recursion_error)
             )
-                
+
                 % This code is dead, it is never entered.
     ;       proc_dead_code.
 
@@ -284,31 +283,31 @@ single_rec_average_recursion_cost(BaseCost, RecCost, AvgMaxDepth) =
     % goal_recursion_data(RecursiveCallees, Goal, GoalPath,
     %   init_recursion_data, RecursionData)
     %
-    % Compute RecursionData about Goal if RecursiveCalls are calls that may
-    % eventually lead to Goal.
+    % Compute RecursionData about Goal if RecursiveCalls are calls
+    % that may eventually lead to Goal.
     %
-:- pred goal_recursion_data(clique_ptr::in, 
+:- pred goal_recursion_data(clique_ptr::in,
     map(goal_path, cost_and_callees)::in, goal_path::in,
     goal_rep(coverage_info)::in, recursion_data::out) is det.
 
-goal_recursion_data(ThisClique, CallSiteMap, GoalPath, GoalRep, 
+goal_recursion_data(ThisClique, CallSiteMap, GoalPath, GoalRep,
         !:RecursionData) :-
     GoalRep = goal_rep(GoalExpr, Detism, CoverageInfo),
     ( get_coverage_before(CoverageInfo, CallsPrime) ->
         Calls = CallsPrime
     ;
-        error(this_file ++ "couldn't retrive coverage information")
+        unexpected($module, $pred, "couldn't retrive coverage information")
     ),
     ( Calls = 0 ->
         !:RecursionData = proc_dead_code
     ;
         (
             GoalExpr = conj_rep(Conjs),
-            conj_recursion_data(ThisClique, CallSiteMap, GoalPath, 1, Conjs, 
+            conj_recursion_data(ThisClique, CallSiteMap, GoalPath, 1, Conjs,
                 !:RecursionData)
         ;
             GoalExpr = disj_rep(Disjs),
-            disj_recursion_data(ThisClique, CallSiteMap, GoalPath, 1, Disjs, 
+            disj_recursion_data(ThisClique, CallSiteMap, GoalPath, 1, Disjs,
                 !:RecursionData)
         ;
             GoalExpr = switch_rep(_, _, Cases),
@@ -316,13 +315,13 @@ goal_recursion_data(ThisClique, CallSiteMap, GoalPath, GoalRep,
                 float(Calls), Calls, !:RecursionData)
         ;
             GoalExpr = ite_rep(Cond, Then, Else),
-            ite_recursion_data(ThisClique, CallSiteMap, GoalPath, 
-                Cond, Then, Else, Calls, !:RecursionData) 
+            ite_recursion_data(ThisClique, CallSiteMap, GoalPath,
+                Cond, Then, Else, Calls, !:RecursionData)
         ;
-            ( 
+            (
                 GoalExpr = negation_rep(SubGoal),
                 GoalPathStep = step_neg
-            ; 
+            ;
                 GoalExpr = scope_rep(SubGoal, MaybeCut),
                 GoalPathStep = step_scope(MaybeCut)
             ),
@@ -351,33 +350,33 @@ goal_recursion_data(ThisClique, CallSiteMap, GoalPath, GoalRep,
             !RecursionData)
     ).
 
-:- pred conj_recursion_data(clique_ptr::in, 
+:- pred conj_recursion_data(clique_ptr::in,
     map(goal_path, cost_and_callees)::in, goal_path::in, int::in,
     list(goal_rep(coverage_info))::in, recursion_data::out) is det.
 
-    % An empty conjunction is true, there is exactly one trival path through it
-    % with 0 recursive calls.
 conj_recursion_data(_, _, _, _, [], simple_recursion_data(0.0, 0)).
-conj_recursion_data(ThisClique, CallSiteMap, GoalPath, ConjNum, 
-        [Conj | Conjs], RecursionData) :- 
-    goal_recursion_data(ThisClique, CallSiteMap, 
-        goal_path_add_at_end(GoalPath, step_conj(ConjNum)), Conj, 
+    % An empty conjunction is true, there is exactly one trivial path
+    % through it with 0 recursive calls.
+conj_recursion_data(ThisClique, CallSiteMap, GoalPath, ConjNum,
+        [Conj | Conjs], RecursionData) :-
+    goal_recursion_data(ThisClique, CallSiteMap,
+        goal_path_add_at_end(GoalPath, step_conj(ConjNum)), Conj,
         ConjRecursionData),
     (
         ConjRecursionData = proc_dead_code,
-        % If the first conjunct is dead then the remaining ones will also be
-        % dead.  This speeds up execution and avoids a divide by zero when
-        % calculating ConjSuccessProb below.
+        % If the first conjunct is dead then the remaining ones will
+        % also be dead. This speeds up execution and avoids a divide by zero
+        % when calculating ConjSuccessProb below.
         RecursionData = proc_dead_code
     ;
-        ConjRecursionData = recursion_data(_, _, _), 
-        
+        ConjRecursionData = recursion_data(_, _, _),
+
         conj_recursion_data(ThisClique, CallSiteMap, GoalPath, ConjNum + 1,
             Conjs, ConjsRecursionData0),
         CanFail = detism_get_can_fail(Conj ^ goal_detism_rep),
         (
             CanFail = cannot_fail_rep,
-            merge_recursion_data_sequence(ConjRecursionData, 
+            merge_recursion_data_sequence(ConjRecursionData,
                 ConjsRecursionData0, RecursionData)
         ;
             CanFail = can_fail_rep,
@@ -387,9 +386,9 @@ conj_recursion_data(ThisClique, CallSiteMap, GoalPath, ConjNum,
 
             success_probability_from_coverage(Conj ^ goal_annotation,
                 ConjSuccessProb),
-            recursion_data_and_probability(ConjSuccessProb, ConjsRecursionData0,
-                ConjsRecursionData),
-            
+            recursion_data_and_probability(ConjSuccessProb,
+                ConjsRecursionData0, ConjsRecursionData),
+
             ConjFailureProb = not_probability(ConjSuccessProb),
             Failure0 = simple_recursion_data(0.0, 0),
             recursion_data_and_probability(ConjFailureProb, Failure0, Failure),
@@ -400,38 +399,37 @@ conj_recursion_data(ThisClique, CallSiteMap, GoalPath, ConjNum,
         )
     ).
 
-:- pred disj_recursion_data(clique_ptr::in, 
-    map(goal_path, cost_and_callees)::in, goal_path::in, int::in, 
-    list(goal_rep(coverage_info))::in, recursion_data::out)
-    is det.
+:- pred disj_recursion_data(clique_ptr::in,
+    map(goal_path, cost_and_callees)::in, goal_path::in, int::in,
+    list(goal_rep(coverage_info))::in, recursion_data::out) is det.
 
 disj_recursion_data(_, _, _, _, [], simple_recursion_data(0.0, 0)).
-disj_recursion_data(ThisClique, CallSiteMap, GoalPath, DisjNum, 
+disj_recursion_data(ThisClique, CallSiteMap, GoalPath, DisjNum,
         [Disj | Disjs], RecursionData) :-
-    % Handle only semidet and committed-choice disjunctions, once a goal
-    % succeeds it cannot be re-entered.
+    % Handle only semidet and committed-choice disjunctions, which cannot be
+    % re-entered once a disjunct succeeds.
     goal_recursion_data(ThisClique, CallSiteMap,
         goal_path_add_at_end(GoalPath, step_disj(DisjNum)), Disj,
         DisjRecursionData),
     (
         DisjRecursionData = proc_dead_code,
-        % If the first disjunct was never tried then no other disjuncts will
+        % If the first disjunct was never tried, then no other disjuncts will
         % ever be tried.
         RecursionData = proc_dead_code
     ;
         DisjRecursionData = recursion_data(_, _, _),
         success_probability_from_coverage(Disj ^ goal_annotation,
             DisjSuccessProb),
-        DisjFailureProb = not_probability(DisjSuccessProb), 
-        
+        DisjFailureProb = not_probability(DisjSuccessProb),
+
         % The code can branch here, either it tries the next disjuct, which we
-        % represent as DisjsRecursionData.
+        % represent as DisjsRecursionData, ...
         disj_recursion_data(ThisClique, CallSiteMap, GoalPath, DisjNum + 1,
             Disjs, DisjsRecursionData0),
         recursion_data_and_probability(DisjFailureProb, DisjsRecursionData0,
             DisjsRecursionData),
 
-        % Or it succeeds which we represent as finished.
+        % ... or it succeeds, which we represent as finished.
         Finish0 = simple_recursion_data(0.0, 0),
         recursion_data_and_probability(DisjSuccessProb, Finish0, Finish),
 
@@ -447,7 +445,7 @@ disj_recursion_data(ThisClique, CallSiteMap, GoalPath, DisjNum,
     is det.
 
 success_probability_from_coverage(Coverage, SuccessProb) :-
-    ( 
+    (
         get_coverage_before_and_after(Coverage, Before, After)
     ->
         ( After > Before ->
@@ -457,20 +455,20 @@ success_probability_from_coverage(Coverage, SuccessProb) :-
             SuccessProb = probable(float(After) / float(Before))
         )
     ;
-        error(this_file ++ "expected complete coverage information")
-    ). 
+        unexpected($module, $pred, "expected complete coverage information")
+    ).
 
-:- pred ite_recursion_data(clique_ptr::in, 
-    map(goal_path, cost_and_callees)::in, goal_path::in, 
+:- pred ite_recursion_data(clique_ptr::in,
+    map(goal_path, cost_and_callees)::in, goal_path::in,
     goal_rep(coverage_info)::in, goal_rep(coverage_info)::in,
     goal_rep(coverage_info)::in, int::in, recursion_data::out) is det.
 
 ite_recursion_data(ThisClique, CallSiteMap, GoalPath, Cond, Then, Else,
         Calls, !:RecursionData) :-
-    goal_recursion_data(ThisClique, CallSiteMap, 
+    goal_recursion_data(ThisClique, CallSiteMap,
         goal_path_add_at_end(GoalPath, step_ite_cond), Cond,
         CondRecursionData),
-    goal_recursion_data(ThisClique, CallSiteMap, 
+    goal_recursion_data(ThisClique, CallSiteMap,
         goal_path_add_at_end(GoalPath, step_ite_then), Then,
         ThenRecursionData0),
     goal_recursion_data(ThisClique, CallSiteMap,
@@ -486,24 +484,23 @@ ite_recursion_data(ThisClique, CallSiteMap, GoalPath, Cond, Then, Else,
         ThenProb = probable(float(ThenCalls) / CallsF),
         ElseProb = probable(float(ElseCalls) / CallsF)
     ;
-        error(this_file ++ "couldn't retrive coverage information")
+        unexpected($module, $pred, "couldn't retrive coverage information")
     ),
-    recursion_data_and_probability(ThenProb, ThenRecursionData0,
-        ThenRecursionData),
-    recursion_data_and_probability(ElseProb, ElseRecursionData0,
-        ElseRecursionData),
+    recursion_data_and_probability(ThenProb,
+        ThenRecursionData0, ThenRecursionData),
+    recursion_data_and_probability(ElseProb,
+        ElseRecursionData0, ElseRecursionData),
 
     % Because the condition goal has coverage information as if it is
-    % entered before either branch, we have to model it in the same way
-    % here, even though it would be fesable to model it sas something
-    % that happens in sequence with both the then and else branches
-    % (within each branch).
-    merge_recursion_data_after_branch(ThenRecursionData, 
+    % entered before either branch, we have to model it in the same way here,
+    % even though it would be fesable to model it sas something that happens
+    % in sequence with both the then and else branches (within each branch).
+    merge_recursion_data_after_branch(ThenRecursionData,
         ElseRecursionData, !:RecursionData),
     merge_recursion_data_sequence(CondRecursionData, !RecursionData).
 
-:- pred switch_recursion_data(clique_ptr::in, 
-    map(goal_path, cost_and_callees)::in, goal_path::in, int::in, 
+:- pred switch_recursion_data(clique_ptr::in,
+    map(goal_path, cost_and_callees)::in, goal_path::in, int::in,
     list(case_rep(coverage_info))::in, float::in, int::in,
     recursion_data::out) is det.
 
@@ -513,16 +510,16 @@ switch_recursion_data(_, _, _, _, [], TotalCalls, CallsRemaining,
     FailProb = probable(float(CallsRemaining) / TotalCalls),
     RecursionData0 = simple_recursion_data(0.0, 0),
     recursion_data_and_probability(FailProb, RecursionData0, RecursionData).
-switch_recursion_data(ThisClique, CallSiteMap, GoalPath, CaseNum, 
+switch_recursion_data(ThisClique, CallSiteMap, GoalPath, CaseNum,
         [Case | Cases], TotalCalls, CallsRemaining, RecursionData) :-
     Case = case_rep(_, _, Goal),
-    goal_recursion_data(ThisClique, CallSiteMap, 
-        goal_path_add_at_end(GoalPath, step_switch(CaseNum, no)), Goal, 
+    goal_recursion_data(ThisClique, CallSiteMap,
+        goal_path_add_at_end(GoalPath, step_switch(CaseNum, no)), Goal,
         CaseRecursionData0),
     ( get_coverage_before(Goal ^ goal_annotation, CallsPrime) ->
         Calls = CallsPrime
     ;
-        error(this_file ++ "expected coverage information")
+        unexpected($module, $pred, "expected coverage information")
     ),
     CaseProb = probable(float(Calls) / TotalCalls),
     recursion_data_and_probability(CaseProb, CaseRecursionData0,
@@ -532,11 +529,11 @@ switch_recursion_data(ThisClique, CallSiteMap, GoalPath, CaseNum,
     merge_recursion_data_after_branch(CaseRecursionData, CasesRecursionData,
         RecursionData).
 
-:- pred atomic_goal_recursion_data(clique_ptr::in, 
+:- pred atomic_goal_recursion_data(clique_ptr::in,
     map(goal_path, cost_and_callees)::in, goal_path::in,
     atomic_goal_rep::in, recursion_data::out) is det.
 
-atomic_goal_recursion_data(ThisClique, CallSiteMap, GoalPath, AtomicGoal, 
+atomic_goal_recursion_data(ThisClique, CallSiteMap, GoalPath, AtomicGoal,
         RecursionData) :-
     (
         % All these things have trivial cost except for foreign code whose cost
@@ -589,27 +586,38 @@ atomic_goal_recursion_data(ThisClique, CallSiteMap, GoalPath, AtomicGoal,
     %         rec2
     %     )
     % )
-    % 
+    %
     % + The cost of entering a base case is the weighted average of the costs
     %   of the two base cases.
-    % + The number of times one enteres a base case is the sum of the
+    % + The number of times one enters a base case is the sum of the
     %   individual counts.
     % + The above two rules are also true for recursive cases.
     %
-:- pred merge_recursion_data_after_branch(recursion_data::in, 
+:- pred merge_recursion_data_after_branch(recursion_data::in,
     recursion_data::in, recursion_data::out) is det.
 
 merge_recursion_data_after_branch(A, B, Result) :-
-    A = recursion_data(RecursionsA, MaxLevelA, ErrorsA),
-    B = recursion_data(RecursionsB, MaxLevelB, ErrorsB),
-    Recursions0 = assoc_list.merge(RecursionsA, RecursionsB),
-    condense_recursions(Recursions0, Recursions),
-    MaxLevel = max(MaxLevelA, MaxLevelB),
-    Errors = union(ErrorsA, ErrorsB),
-    Result = recursion_data(Recursions, MaxLevel, Errors).
-merge_recursion_data_after_branch(A, proc_dead_code, A) :-
-    A = recursion_data(_, _, _).
-merge_recursion_data_after_branch(proc_dead_code, A, A).
+    (
+        A = recursion_data(RecursionsA, MaxLevelA, ErrorsA),
+        B = recursion_data(RecursionsB, MaxLevelB, ErrorsB),
+        Recursions0 = assoc_list.merge(RecursionsA, RecursionsB),
+        condense_recursions(Recursions0, Recursions),
+        MaxLevel = max(MaxLevelA, MaxLevelB),
+        Errors = union(ErrorsA, ErrorsB),
+        Result = recursion_data(Recursions, MaxLevel, Errors)
+    ;
+        A = recursion_data(_, _, _),
+        B = proc_dead_code,
+        Result = A
+    ;
+        A = proc_dead_code,
+        B = recursion_data(_, _, _),
+        Result = B
+    ;
+        A = proc_dead_code,
+        B = proc_dead_code,
+        Result = proc_dead_code
+    ).
 
     % merge_recursion_data_sequence(A, B, Merged).
     %
@@ -628,11 +636,11 @@ merge_recursion_data_after_branch(proc_dead_code, A, A).
     % ;
     %     rec2
     % )
-    % 
-    % It's like algabra!  Teating the conjunction as multiplication and
+    %
+    % It's like algabra! Treating the conjunction as multiplication and
     % disjunction as addition we might factorise it as:
     % Note that this is just to show the pattern I can see here.
-    % 
+    %
     % base1*base2 + base1*rec2 + base2*rec1 + rec1*rec2.
     %
     % That is, there is one base case, two recursive cases, and a doubly
@@ -648,24 +656,30 @@ merge_recursion_data_after_branch(proc_dead_code, A, A).
     %   components.
     % + Similarly for the other cases.
     %
-:- pred merge_recursion_data_sequence(recursion_data::in, 
+:- pred merge_recursion_data_sequence(recursion_data::in,
     recursion_data::in, recursion_data::out) is det.
 
 merge_recursion_data_sequence(A, B, Result) :-
-    A = recursion_data(RecursionsA, MaxLevelA, ErrorsA),
-    B = recursion_data(RecursionsB, MaxLevelB, ErrorsB),
-    recursions_cross_product(RecursionsA, RecursionsB, Recursions0),
-    sort(Recursions0, Recursions1),
-    condense_recursions(Recursions1, Recursions),
-    % The maximum number of recursions on any path will be the some of the
-    % maximum number of recursions on two conjoined paths since all paths are
-    % conjoined in the cross product.
-    MaxLevel = MaxLevelA + MaxLevelB,
-    Errors = union(ErrorsA, ErrorsB),
-    Result = recursion_data(Recursions, MaxLevel, Errors).
-merge_recursion_data_sequence(A, proc_dead_code, proc_dead_code) :-
-    A = recursion_data(_, _, _).
-merge_recursion_data_sequence(proc_dead_code, _, proc_dead_code).
+    (
+        A = recursion_data(RecursionsA, MaxLevelA, ErrorsA),
+        B = recursion_data(RecursionsB, MaxLevelB, ErrorsB),
+        recursions_cross_product(RecursionsA, RecursionsB, Recursions0),
+        sort(Recursions0, Recursions1),
+        condense_recursions(Recursions1, Recursions),
+        % The maximum number of recursions on any path will be the sum of
+        % the maximum number of recursions on the two conjoined paths,
+        % since all paths are conjoined in the cross product.
+        MaxLevel = MaxLevelA + MaxLevelB,
+        Errors = union(ErrorsA, ErrorsB),
+        Result = recursion_data(Recursions, MaxLevel, Errors)
+    ;
+        A = recursion_data(_, _, _),
+        B = proc_dead_code,
+        Result = proc_dead_code
+    ;
+        A = proc_dead_code,
+        Result = proc_dead_code
+    ).
 
 :- pred condense_recursions(assoc_list(int, recursion_level)::in,
     assoc_list(int, recursion_level)::out) is det.
@@ -674,7 +688,7 @@ condense_recursions([], []).
 condense_recursions([Num - Rec | Pairs0], Pairs) :-
     condense_recursions_2(Num - Rec, Pairs0, Pairs).
 
-:- pred condense_recursions_2(pair(int, recursion_level)::in, 
+:- pred condense_recursions_2(pair(int, recursion_level)::in,
     assoc_list(int, recursion_level)::in,
     assoc_list(int, recursion_level)::out) is det.
 
@@ -684,7 +698,8 @@ condense_recursions_2(NumA - RecA, [NumB - RecB | Pairs0], Pairs) :-
         RecA = recursion_level(CostA, ProbabilityA),
         RecB = recursion_level(CostB, ProbabilityB),
         weighted_average(
-            map(probability_to_float, [ProbabilityA, ProbabilityB]),
+            [probability_to_float(ProbabilityA),
+            probability_to_float(ProbabilityB)],
             [CostA, CostB], Cost),
         Probability = or(ProbabilityA, ProbabilityB),
         Rec = recursion_level(Cost, Probability),
@@ -705,7 +720,7 @@ condense_recursions_2(NumA - RecA, [NumB - RecB | Pairs0], Pairs) :-
     assoc_list(int, recursion_level)::in,
     assoc_list(int, recursion_level)::out) is det.
 
-recursions_cross_product([], _, []). 
+recursions_cross_product([], _, []).
 recursions_cross_product([NumA - RecA | PairsA], PairsB, Pairs) :-
     recursions_cross_product_2(NumA, RecA, PairsB, InnerLoop),
     recursions_cross_product(PairsA, PairsB, OuterLoopTail),
@@ -716,7 +731,7 @@ recursions_cross_product([NumA - RecA | PairsA], PairsB, Pairs) :-
     assoc_list(int, recursion_level)::out) is det.
 
 recursions_cross_product_2(_Num, _Rec, [], []).
-recursions_cross_product_2(NumA, RecA@recursion_level(CostA, ProbA), 
+recursions_cross_product_2(NumA, RecA@recursion_level(CostA, ProbA),
         [NumB - recursion_level(CostB, ProbB) | PairsB], Pairs) :-
     recursions_cross_product_2(NumA, RecA, PairsB, Pairs0),
     Num = NumA + NumB,
@@ -734,11 +749,11 @@ recursion_data_and_probability(Prob,
     map_values(recursion_level_and_probability(Prob), !Recursions).
 recursion_data_and_probability(_, proc_dead_code, proc_dead_code).
 
-:- pred recursion_level_and_probability(probability::in, T::in, 
+:- pred recursion_level_and_probability(probability::in, T::in,
     recursion_level::in, recursion_level::out) is det.
 
-recursion_level_and_probability(AndProb, _, recursion_level(Cost, Prob0), 
-        recursion_level(Cost, Prob)) :-
+recursion_level_and_probability(AndProb, _,
+        recursion_level(Cost, Prob0), recursion_level(Cost, Prob)) :-
     Prob = and(Prob0, AndProb).
 
 :- pred recursion_data_add_error(recursion_error::in, recursion_data::in,
@@ -761,12 +776,12 @@ recursion_data_add_error(Error, !RecursionData) :-
     %
 :- func simple_recursion_data(float, int) = recursion_data.
 
-simple_recursion_data(Cost, Calls) = 
+simple_recursion_data(Cost, Calls) =
     recursion_data([Calls - recursion_level(Cost, certain)], Calls, init).
 
 :- func error_to_string(recursion_error) = string.
 
-error_to_string(re_unhandled_determinism(Detism)) = 
+error_to_string(re_unhandled_determinism(Detism)) =
     format("%s code is not handled", [s(string(Detism))]).
 
 %----------------------------------------------------------------------------%
@@ -786,16 +801,16 @@ create_recursion_types_frequency_report(Deep, MaybeReport) :-
     ;
         MaybeProgRepResult = yes(ok(_)),
         Cliques = Deep ^ clique_index,
-        size(Cliques, NumCliques),  
-        array_foldl_from_1(rec_types_freq_build_histogram(Deep), Cliques, 
+        size(Cliques, NumCliques),
+        array_foldl_from_1(rec_types_freq_build_histogram(Deep), Cliques,
             map.init, Histogram0),
         finalize_histogram(Deep, NumCliques, Histogram0, Histogram),
         MaybeReport = ok(recursion_types_frequency_report(Histogram))
     ).
 
 :- pred rec_types_freq_build_histogram(deep::in, int::in, clique_ptr::in,
-    map(recursion_type_simple, recursion_type_raw_freq_data)::in, 
-    map(recursion_type_simple, recursion_type_raw_freq_data)::out) is det. 
+    map(recursion_type_simple, recursion_type_raw_freq_data)::in,
+    map(recursion_type_simple, recursion_type_raw_freq_data)::out) is det.
 
 rec_types_freq_build_histogram(Deep, _, CliquePtr, !Histogram) :-
     trace [io(!IO)] (
@@ -817,11 +832,11 @@ rec_types_freq_build_histogram(Deep, _, CliquePtr, !Histogram) :-
     (
         MaybeFirstPDPtr = yes(FirstPDPtr),
         lookup_proc_dynamics(Deep ^ proc_dynamics, FirstPDPtr, FirstPD),
-        FirstPSPtr = FirstPD ^ pd_proc_static,  
-        PDesc = describe_proc(Deep, FirstPSPtr), 
+        FirstPSPtr = FirstPD ^ pd_proc_static,
+        PDesc = describe_proc(Deep, FirstPSPtr),
         lookup_pd_own(Deep ^ pd_own, FirstPDPtr, ProcOwn),
         lookup_pd_desc(Deep ^ pd_desc, FirstPDPtr, ProcInherit),
-        FirstProcInfo = first_proc_info(PDesc, 
+        FirstProcInfo = first_proc_info(PDesc,
             own_and_inherit_prof_info(ProcOwn, ProcInherit)),
         MaybeFirstProcInfo = yes(FirstProcInfo)
     ;
@@ -829,7 +844,7 @@ rec_types_freq_build_histogram(Deep, _, CliquePtr, !Histogram) :-
         MaybeFirstProcInfo = no
     ),
     foldl(update_histogram(MaybeFirstProcInfo), SimpleTypes, !Histogram).
-            
+
 :- type first_proc_info
     --->    first_proc_info(
                 fpi_pdesc               :: proc_desc,
@@ -858,7 +873,7 @@ add_own_and_inherit_prof_info(
     --->    recursion_type_raw_freq_data(
                 rtrfd_freq              :: int,
                 rtrfd_maybe_prof_info   :: maybe(own_and_inherit_prof_info),
-                rtrfd_entry_procs       :: map(proc_static_ptr, 
+                rtrfd_entry_procs       :: map(proc_static_ptr,
                     recursion_type_raw_proc_freq_data)
             ).
 
@@ -870,8 +885,8 @@ add_own_and_inherit_prof_info(
             ).
 
 :- pred update_histogram(maybe(first_proc_info)::in,
-    recursion_type_simple::in, 
-    map(recursion_type_simple, recursion_type_raw_freq_data)::in, 
+    recursion_type_simple::in,
+    map(recursion_type_simple, recursion_type_raw_freq_data)::in,
     map(recursion_type_simple, recursion_type_raw_freq_data)::out) is det.
 
 update_histogram(MaybeFirstProcInfo, SimpleType, !Histogram) :-
@@ -881,7 +896,7 @@ update_histogram(MaybeFirstProcInfo, SimpleType, !Histogram) :-
             MaybeFirstProcInfo = yes(FirstProcInfo),
             (
                 MaybeProfInfo0 = yes(ProfInfo0),
-                add_own_and_inherit_prof_info(FirstProcInfo ^ fpi_prof_info, 
+                add_own_and_inherit_prof_info(FirstProcInfo ^ fpi_prof_info,
                     ProfInfo0, ProfInfo)
             ;
                 MaybeProfInfo0 = no,
@@ -912,26 +927,26 @@ update_histogram(MaybeFirstProcInfo, SimpleType, !Histogram) :-
     svmap.set(SimpleType, Data, !Histogram).
 
 :- pred update_procs_map(first_proc_info::in,
-    map(proc_static_ptr, recursion_type_raw_proc_freq_data)::in, 
+    map(proc_static_ptr, recursion_type_raw_proc_freq_data)::in,
     map(proc_static_ptr, recursion_type_raw_proc_freq_data)::out) is det.
 
 update_procs_map(FirstProcInfo, !Map) :-
     FirstProcInfo = first_proc_info(PSDesc, FirstProfInfo),
     PsPtr = PSDesc ^ pdesc_ps_ptr,
     ( map.search(!.Map, PsPtr, ProcFreqData0) ->
-        ProcFreqData0 = 
+        ProcFreqData0 =
             recursion_type_raw_proc_freq_data(Count0, ProfInfo0, ProcDesc),
         add_own_and_inherit_prof_info(FirstProfInfo, ProfInfo0, ProfInfo),
         Count = Count0 + 1,
-        ProcFreqData = 
+        ProcFreqData =
             recursion_type_raw_proc_freq_data(Count, ProfInfo, ProcDesc)
     ;
-        ProcFreqData = 
+        ProcFreqData =
             recursion_type_raw_proc_freq_data(1, FirstProfInfo, PSDesc)
     ),
     svmap.set(PsPtr, ProcFreqData, !Map).
 
-:- pred recursion_type_to_simple_type(recursion_type::in, 
+:- pred recursion_type_to_simple_type(recursion_type::in,
     recursion_type_simple::out) is multi.
 
 recursion_type_to_simple_type(rt_not_recursive, rts_not_recursive).
@@ -947,19 +962,19 @@ recursion_type_to_simple_type(rt_errors(Errors), rts_error(Error)) :-
     member(Error, Errors).
 recursion_type_to_simple_type(rt_errors(_), rts_total_error_instances).
 
-:- pred finalize_histogram(deep::in, int::in, 
+:- pred finalize_histogram(deep::in, int::in,
     map(recursion_type_simple, recursion_type_raw_freq_data)::in,
-    map(recursion_type_simple, recursion_type_freq_data)::out) is det. 
+    map(recursion_type_simple, recursion_type_freq_data)::out) is det.
 
 finalize_histogram(Deep, NumCliques, !Histogram) :-
-    map_values(finalize_histogram_rec_type(Deep, float(NumCliques)), 
+    map_values(finalize_histogram_rec_type(Deep, float(NumCliques)),
         !Histogram).
 
-:- pred finalize_histogram_rec_type(deep::in, float::in, 
+:- pred finalize_histogram_rec_type(deep::in, float::in,
     recursion_type_simple::in,
     recursion_type_raw_freq_data::in, recursion_type_freq_data::out) is det.
 
-finalize_histogram_rec_type(Deep, NumCliques, _RecursionType, 
+finalize_histogram_rec_type(Deep, NumCliques, _RecursionType,
         recursion_type_raw_freq_data(Freq, MaybeProfInfo, !.EntryProcs),
         recursion_type_freq_data(Freq, Percent, MaybeSummary, !:EntryProcs)) :-
     Percent = percent(float(Freq) / NumCliques),
@@ -969,7 +984,7 @@ finalize_histogram_rec_type(Deep, NumCliques, _RecursionType,
     ;
         MaybeProfInfo = yes(ProfInfo),
         ProfInfo = own_and_inherit_prof_info(Own, Inherit),
-        own_and_inherit_to_perf_row_data(Deep, unit, Own, Inherit, Summary), 
+        own_and_inherit_to_perf_row_data(Deep, unit, Own, Inherit, Summary),
         MaybeSummary = yes(Summary)
     ),
     map_values(finalize_histogram_proc_rec_type(Deep, NumCliques), !EntryProcs).
@@ -989,7 +1004,7 @@ finalize_histogram_proc_rec_type(Deep, NumCliques, _PSPtr,
 %----------------------------------------------------------------------------%
 %----------------------------------------------------------------------------%
 
-recursion_type_get_maybe_avg_max_depth(rt_not_recursive, 
+recursion_type_get_maybe_avg_max_depth(rt_not_recursive,
     yes(recursion_depth_from_float(0.0))).
 recursion_type_get_maybe_avg_max_depth(rt_single(_, _, Depth, _, _),
     yes(recursion_depth_from_float(Depth))).
@@ -998,12 +1013,6 @@ recursion_type_get_maybe_avg_max_depth(rt_mutual_recursion(_), no).
 recursion_type_get_maybe_avg_max_depth(rt_other(_), no).
 recursion_type_get_maybe_avg_max_depth(rt_errors(_), no).
 
-%----------------------------------------------------------------------------%
-
-:- func this_file = string.
-
-this_file = "recursion_patterns.m: ".
-
 %----------------------------------------------------------------------------%
 :- end_module recursion_patterns.
 %----------------------------------------------------------------------------%
diff --git a/deep_profiler/report.m b/deep_profiler/report.m
index f7a46c13c..38ebf841b 100644
--- a/deep_profiler/report.m
+++ b/deep_profiler/report.m
@@ -159,7 +159,7 @@
                 % since it will not find an existing one it can reuse;
                 % q's proc_static won't point to an active proc_dynamic, and
                 % the call site will not supply one either.
-                % 
+                %
                 % We could modify the code we invoke at call ports to keep a
                 % list of the proc_dynamics of the procedures known to be in
                 % the current clique, and to reuse the proc_dynamic of the
@@ -264,14 +264,14 @@
                 rlr_non_rec_calls_cost          :: float,
                 rlr_rec_calls_ex_chld_cost      :: float
             ).
- 
+
 :- type recursion_types_frequency_report
     --->    recursion_types_frequency_report(
                 rtfr_histogram                  :: recursion_type_histogram
             ).
 
-:- type recursion_type_histogram == 
-    map(recursion_type_simple, recursion_type_freq_data). 
+:- type recursion_type_histogram ==
+    map(recursion_type_simple, recursion_type_freq_data).
 
 :- type recursion_type_simple
     --->    rts_not_recursive
@@ -676,14 +676,14 @@
 
 :- pred proc_label_from_proc_desc(deep::in, proc_desc::in,
     string_proc_label::out) is det.
-    
+
     % foldl(add_call_site_report_to_map(CallSiteReports, map.init,
     %   CallSitesMap).
     %
     % Build a map from goal paths to call site reports.
     %
-:- pred add_call_site_report_to_map(clique_call_site_report::in, 
-    map(goal_path, clique_call_site_report)::in, 
+:- pred add_call_site_report_to_map(clique_call_site_report::in,
+    map(goal_path, clique_call_site_report)::in,
     map(goal_path, clique_call_site_report)::out) is det.
 
 %-----------------------------------------------------------------------------%
@@ -701,7 +701,7 @@ proc_label_from_proc_desc(Deep, ProcDesc, ProcLabel) :-
     ProcLabel = ProcStatic ^ ps_id.
 
 add_call_site_report_to_map(CallSite, !Map) :-
-    GoalPath = CallSite ^ ccsr_call_site_summary ^ perf_row_subject 
+    GoalPath = CallSite ^ ccsr_call_site_summary ^ perf_row_subject
         ^ csdesc_goal_path,
     svmap.det_insert(GoalPath, CallSite, !Map).
 
diff --git a/deep_profiler/startup.m b/deep_profiler/startup.m
index e21c1a5ef..5a5b4ecbd 100644
--- a/deep_profiler/startup.m
+++ b/deep_profiler/startup.m
@@ -294,7 +294,7 @@ startup(Machine, ScriptName, DataFileName, Canonical, MaybeOutputStream,
     array.init(NCSSs, zero_inherit_prof_info, CSSDesc0),
     array.init(NPDs, map.init, PDCompTable0),
     array.init(NCSDs, map.init, CSDCompTable0),
-    CoverageDataType = InitStats ^ prs_deep_flags ^ df_coverage_data_type, 
+    CoverageDataType = InitStats ^ prs_deep_flags ^ df_coverage_data_type,
     (
         CoverageDataType = no_coverage_data,
         MaybeStaticCoverage0 = no
@@ -312,7 +312,7 @@ startup(Machine, ScriptName, DataFileName, Canonical, MaybeOutputStream,
         ProcCallers, CallSiteStaticMap, CallSiteCalls,
         PDOwn, PDDesc0, CSDDesc0,
         PSOwn0, PSDesc0, CSSOwn0, CSSDesc0,
-        PDCompTable0, CSDCompTable0, ModuleDataMap, MaybeStaticCoverage0, 
+        PDCompTable0, CSDCompTable0, ModuleDataMap, MaybeStaticCoverage0,
         ExcludeFile, MaybeProcRepFile),
 
     array_foldl_from_1(propagate_to_clique, Cliques, !Deep),
@@ -766,7 +766,7 @@ summarize_proc_dynamics_with_coverage_data(!Deep) :-
     % correect amount of storage.
     NPS = !.Deep ^ profile_stats ^ prs_num_ps + 1,
     array_foldl3_from_1(
-        summarize_proc_dynamic_with_coverage(!.Deep ^ pd_own, 
+        summarize_proc_dynamic_with_coverage(!.Deep ^ pd_own,
             !.Deep ^ pd_desc, !.Deep ^ pd_comp_table),
         !.Deep ^ proc_dynamics,
         init(NPS, zero_own_prof_info), PSOwnArray,
@@ -800,27 +800,25 @@ summarize_proc_dynamic_with_coverage(PDOwnArray, PDDescArray, PDCompTableArray,
         )
     ;
         MaybeDynamicCoverage = no,
-        error(this_file ++ "No coverage point array in proc dynamic")
+        unexpected($module, $pred, "no coverage point array in proc dynamic")
     ).
 
 %-----------------------------------------------------------------------------%
 
 :- pred summarize_call_site_dynamics(deep::in, deep::out) is det.
 
-summarize_call_site_dynamics(Deep0, Deep) :-
-    CSSOwnArray0 = Deep0 ^ css_own,
-    CSSDescArray0 = Deep0 ^ css_desc,
+summarize_call_site_dynamics(!Deep) :-
+    CSSOwnArray0 = !.Deep ^ css_own,
+    CSSDescArray0 = !.Deep ^ css_desc,
     array_foldl2_from_1(
         summarize_call_site_dynamic(
-            Deep0 ^ call_site_static_map,
-            Deep0 ^ call_site_statics, Deep0 ^ csd_desc,
-            Deep0 ^ csd_comp_table),
-        Deep0 ^ call_site_dynamics,
+            !.Deep ^ call_site_static_map, !.Deep ^ call_site_statics,
+            !.Deep ^ csd_desc, !.Deep ^ csd_comp_table),
+        !.Deep ^ call_site_dynamics,
         copy(CSSOwnArray0), CSSOwnArray,
         copy(CSSDescArray0), CSSDescArray),
-    Deep = ((Deep0
-        ^ css_own := CSSOwnArray)
-        ^ css_desc := CSSDescArray).
+    !Deep ^ css_own := CSSOwnArray,
+    !Deep ^ css_desc := CSSDescArray.
 
 :- pred summarize_call_site_dynamic(call_site_static_map::in,
     call_site_statics::in, array(inherit_prof_info)::in,
@@ -884,7 +882,7 @@ summarize_proc_statics_coverage(!Deep) :-
         init(NPS, zero_static_coverage), CoverageArray),
     !Deep ^ maybe_static_coverage := yes(CoverageArray).
 
-:- pred summarize_proc_static_coverage(int::in, proc_static::in, 
+:- pred summarize_proc_static_coverage(int::in, proc_static::in,
     array(static_coverage_info)::array_di,
     array(static_coverage_info)::array_uo) is det.
 
@@ -896,7 +894,7 @@ summarize_proc_static_coverage(Index, PS, !CoverageArray) :-
         array.set(!.CoverageArray, Index, Coverage, !:CoverageArray)
     ;
         MaybeCoverage = no,
-        error(this_file ++ "No coverage data in proc static.")
+        unexpected($module, $pred, "no coverage data in proc static")
     ).
 
 %----------------------------------------------------------------------------%
@@ -1106,12 +1104,6 @@ maybe_report_msg(yes(OutputStream), Msg, !IO) :-
     flush_output(OutputStream, !IO).
 maybe_report_msg(no, _, !IO).
 
-%-----------------------------------------------------------------------------%
-
-:- func this_file = string.
-
-this_file = "startup.m".
-
 %-----------------------------------------------------------------------------%
 :- end_module startup.
 %-----------------------------------------------------------------------------%
diff --git a/deep_profiler/top_procs.m b/deep_profiler/top_procs.m
index 7ef4907de..d840ab034 100644
--- a/deep_profiler/top_procs.m
+++ b/deep_profiler/top_procs.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2001, 2005-2008 The University of Melbourne.
+% Copyright (C) 2001, 2005-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -702,7 +702,8 @@ threshold_value_ps_callseqs_both(Deep, Threshold, PSI) :-
     TotalCallSeqs = OwnCallSeqs + DescCallSeqs,
     float(TotalCallSeqs) > Threshold.
 
-:- pred threshold_value_ps_allocs_self(deep::in, float::in, int::in) is semidet.
+:- pred threshold_value_ps_allocs_self(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_value_ps_allocs_self(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -710,7 +711,8 @@ threshold_value_ps_allocs_self(Deep, Threshold, PSI) :-
     OwnAlloc = allocs(Own),
     float(OwnAlloc) > Threshold.
 
-:- pred threshold_value_ps_allocs_both(deep::in, float::in, int::in) is semidet.
+:- pred threshold_value_ps_allocs_both(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_value_ps_allocs_both(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -722,7 +724,8 @@ threshold_value_ps_allocs_both(Deep, Threshold, PSI) :-
     TotalAlloc = OwnAlloc + DescAlloc,
     float(TotalAlloc) > Threshold.
 
-:- pred threshold_value_ps_words_self(deep::in, float::in, int::in) is semidet.
+:- pred threshold_value_ps_words_self(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_value_ps_words_self(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -744,7 +747,8 @@ threshold_value_ps_words_both(Deep, Threshold, PSI) :-
 
 %-----------------------------------------------------------------------------%
 
-:- pred threshold_percent_ps_time_self(deep::in, float::in, int::in) is semidet.
+:- pred threshold_percent_ps_time_self(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_percent_ps_time_self(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -757,7 +761,8 @@ threshold_percent_ps_time_self(Deep, Threshold, PSI) :-
     RootTotalQuanta = RootOwnQuanta + RootDescQuanta,
     100.0 * float(OwnQuanta) > Threshold * float(RootTotalQuanta).
 
-:- pred threshold_percent_ps_time_both(deep::in, float::in, int::in) is semidet.
+:- pred threshold_percent_ps_time_both(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_percent_ps_time_both(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -774,7 +779,8 @@ threshold_percent_ps_time_both(Deep, Threshold, PSI) :-
     RootTotalQuanta = RootOwnQuanta + RootDescQuanta,
     100.0 * float(TotalQuanta) > Threshold * float(RootTotalQuanta).
 
-:- pred threshold_percent_ps_callseqs_self(deep::in, float::in, int::in) is semidet.
+:- pred threshold_percent_ps_callseqs_self(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_percent_ps_callseqs_self(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -787,7 +793,8 @@ threshold_percent_ps_callseqs_self(Deep, Threshold, PSI) :-
     RootTotalCallSeqs = RootOwnCallSeqs + RootDescCallSeqs,
     100.0 * float(OwnCallSeqs) > Threshold * float(RootTotalCallSeqs).
 
-:- pred threshold_percent_ps_callseqs_both(deep::in, float::in, int::in) is semidet.
+:- pred threshold_percent_ps_callseqs_both(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_percent_ps_callseqs_both(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -804,7 +811,8 @@ threshold_percent_ps_callseqs_both(Deep, Threshold, PSI) :-
     RootTotalCallSeqs = RootOwnCallSeqs + RootDescCallSeqs,
     100.0 * float(TotalCallSeqs) > Threshold * float(RootTotalCallSeqs).
 
-:- pred threshold_percent_ps_allocs_self(deep::in, float::in, int::in) is semidet.
+:- pred threshold_percent_ps_allocs_self(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_percent_ps_allocs_self(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -817,7 +825,8 @@ threshold_percent_ps_allocs_self(Deep, Threshold, PSI) :-
     RootTotalAlloc = RootOwnAlloc + RootDescAlloc,
     100.0 * float(OwnAlloc) > Threshold * float(RootTotalAlloc).
 
-:- pred threshold_percent_ps_allocs_both(deep::in, float::in, int::in) is semidet.
+:- pred threshold_percent_ps_allocs_both(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_percent_ps_allocs_both(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -834,7 +843,8 @@ threshold_percent_ps_allocs_both(Deep, Threshold, PSI) :-
     RootTotalAlloc = RootOwnAlloc + RootDescAlloc,
     100.0 * float(TotalAlloc) > Threshold * float(RootTotalAlloc).
 
-:- pred threshold_percent_ps_words_self(deep::in, float::in, int::in) is semidet.
+:- pred threshold_percent_ps_words_self(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_percent_ps_words_self(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
@@ -847,7 +857,8 @@ threshold_percent_ps_words_self(Deep, Threshold, PSI) :-
     RootTotalWords = RootOwnWords + RootDescWords,
     100.0 * float(OwnWords) > Threshold * float(RootTotalWords).
 
-:- pred threshold_percent_ps_words_both(deep::in, float::in, int::in) is semidet.
+:- pred threshold_percent_ps_words_both(deep::in, float::in, int::in)
+    is semidet.
 
 threshold_percent_ps_words_both(Deep, Threshold, PSI) :-
     PSOwn = Deep ^ ps_own,
diff --git a/deep_profiler/var_use_analysis.m b/deep_profiler/var_use_analysis.m
index 5ccf1280f..711ddd221 100644
--- a/deep_profiler/var_use_analysis.m
+++ b/deep_profiler/var_use_analysis.m
@@ -65,10 +65,10 @@
 
 :- pred var_mode_to_var_use_type(var_mode_rep::in, var_use_type::out) is det.
 
-:- pred pessimistic_var_use_info(var_use_type::in, float::in, 
+:- pred pessimistic_var_use_info(var_use_type::in, float::in,
     var_use_info::out) is det.
 
-:- pred pessimistic_var_use_time(var_use_type::in, float::in, float::out) 
+:- pred pessimistic_var_use_time(var_use_type::in, float::in, float::out)
     is det.
 
 %-----------------------------------------------------------------------------%
@@ -107,16 +107,16 @@
     int, recursion_type, maybe(recursion_depth), float, set(proc_dynamic_ptr),
     var_use_options, maybe_error(var_use_info)).
 :- mode call_site_dynamic_var_use_info(in, in, in,
-    in(recursion_type_known_costs), in(maybe_yes(ground)), in, in, in, out) 
-    is det. 
-:- mode call_site_dynamic_var_use_info(in, in, in, 
+    in(recursion_type_known_costs), in(maybe_yes(ground)), in, in, in, out)
+    is det.
+:- mode call_site_dynamic_var_use_info(in, in, in,
     in, in, in, in, in, out) is det.
 
 :- pred clique_var_use_info(clique_ptr::in, int::in,
     var_use_options::in, maybe_error(var_use_info)::out) is det.
 
 :- pred proc_dynamic_var_use_info(clique_ptr::in,
-    proc_dynamic_ptr::in, int::in, 
+    proc_dynamic_ptr::in, int::in,
     recursion_type::in(recursion_type_known_costs), recursion_depth::in,
     float::in, set(proc_dynamic_ptr)::in, var_use_options::in,
     maybe_error(var_use_info)::out) is det.
@@ -132,10 +132,10 @@
     % Find the first use of a variable in an arbitrary goal.
     %
 :- pred var_first_use(clique_ptr::in,
-    map(goal_path, cost_and_callees)::in, map(goal_path, cs_cost_csq)::in, 
+    map(goal_path, cost_and_callees)::in, map(goal_path, cs_cost_csq)::in,
     recursion_type::in(recursion_type_known_costs), recursion_depth::in,
-    goal_rep(T)::in, goal_path::in, float::in, var_rep::in, 
-    var_use_options::in, var_use_info::out) is det 
+    goal_rep(T)::in, goal_path::in, float::in, var_rep::in,
+    var_use_options::in, var_use_info::out) is det
     <= goal_annotation_with_coverage(T).
 
 %-----------------------------------------------------------------------------%
@@ -158,20 +158,25 @@
 average_var_use(Uses) = var_use_info(CostUntilUse, AvgProcCost, Type) :-
     (
         Uses = [],
-        error(this_file ++ "average_var_use: Cannot average zero items")
+        unexpected($module, $pred, "cannot average zero items")
     ;
         Uses = [var_use_info(_, _, Type) | _],
         foldl2(sum_use_info_costs, Uses, 0.0, SumCost, 0.0, SumProcCost),
         Num = float(length(Uses)),
         CostUntilUse = SumCost / Num,
-        AvgProcCost = SumProcCost / Num, 
-        require(all_true((pred(var_use_info(_, _, TypeI)::in) is semidet :- 
-                    Type = TypeI
-                ), Uses),
-            "average_var_use: Use types do not match")
+        AvgProcCost = SumProcCost / Num,
+        TestType =
+            ( pred(var_use_info(_, _, TypeI)::in) is semidet :-
+                Type = TypeI
+            ),
+        ( all_true(TestType, Uses) ->
+            true
+        ;
+            unexpected($module, $pred, "use types do not match")
+        )
     ).
 
-:- pred sum_use_info_costs(var_use_info::in, float::in, float::out, 
+:- pred sum_use_info_costs(var_use_info::in, float::in, float::out,
     float::in, float::out) is det.
 
 sum_use_info_costs(var_use_info(Cost, ProcCost, _), !AccCost, !AccProcCost) :-
@@ -225,7 +230,7 @@ call_site_dynamic_var_use_info(CSDPtr, ArgPos, RT, Cost, VarUseOptions,
     deep_lookup_call_site_dynamics(Deep, CSDPtr, CSD),
     deep_lookup_clique_index(Deep, CSD ^ csd_caller, ParentCliquePtr),
     recursion_type_get_maybe_avg_max_depth(RT, MaybeCurDepth),
-    call_site_dynamic_var_use_info(ParentCliquePtr, CSDPtr, ArgPos, RT, 
+    call_site_dynamic_var_use_info(ParentCliquePtr, CSDPtr, ArgPos, RT,
         MaybeCurDepth, Cost, set.init, VarUseOptions, MaybeVarUseInfo).
 
 call_site_dynamic_var_use_info(ParentCliquePtr, CSDPtr, ArgNum,
@@ -233,7 +238,7 @@ call_site_dynamic_var_use_info(ParentCliquePtr, CSDPtr, ArgNum,
         MaybeVarUseInfo) :-
     Deep = VarUseOptions ^ vuo_deep,
     deep_lookup_clique_maybe_child(Deep, CSDPtr, MaybeCalleeCliquePtr),
-    ( 
+    (
         MaybeCalleeCliquePtr = yes(CalleeCliquePtr),
         % This is a non-recursive call site.
         clique_var_use_info(CalleeCliquePtr, ArgNum, VarUseOptions,
@@ -255,7 +260,7 @@ call_site_dynamic_var_use_info(ParentCliquePtr, CSDPtr, ArgNum,
             )
         ->
             pessimistic_var_use_info(VarUseOptions ^ vuo_var_use_type, Cost,
-                VarUseInfo), 
+                VarUseInfo),
             MaybeVarUseInfo = ok(VarUseInfo)
         ;
             (
@@ -265,7 +270,7 @@ call_site_dynamic_var_use_info(ParentCliquePtr, CSDPtr, ArgNum,
                 (
                     MaybeDepth0 = yes(Depth0)
                 ;
-                    error("call_site_dynamic_var_use_info: " ++ 
+                    error("call_site_dynamic_var_use_info: " ++
                         "A depth must be provided for known recursion types")
                 ),
                 recursion_depth_descend(Depth0, Depth),
@@ -323,7 +328,7 @@ clique_var_use_info(CliquePtr, ArgNum, VarUseOptions, MaybeVarUseInfo) :-
         )
     ;
         MaybeFirstProc = no,
-        error(this_file ++ "Clique has no first procedure")
+        unexpected($module, $pred, "clique has no first procedure")
     ).
 
 proc_dynamic_var_use_info(CliquePtr, PDPtr, ArgNum, RecursionType,
@@ -342,18 +347,19 @@ proc_dynamic_var_use_info(CliquePtr, PDPtr, ArgNum, RecursionType,
                 true
             ;
                 PDPtr = proc_dynamic_ptr(PDNum),
-                error(format(
-                    "%s: Var uses do not match, passed: %s calculated from "
+                string.format(
+                    "Var uses do not match, passed: %s calculated from "
                     ++ "procrep: %s, Arg %d in proc dynamic %d",
-                    [s(this_file), s(string(VarUseType)),
-                     s(string(ComputedUse)), i(ArgNum), i(PDNum)]))
+                    [s(string(VarUseType)), s(string(ComputedUse)),
+                     i(ArgNum), i(PDNum)], Msg),
+                unexpected($module, $pred, Msg)
             ),
 
             % Prepare callsite information.
             proc_dynamic_paired_call_site_slots(Deep, PDPtr, Slots),
             foldl(build_call_site_cost_and_callee_map(Deep),
                 Slots, map.init, CallSiteCostMap),
-            
+
             % We're following a recursive call, therefore we descend one level.
             recursion_depth_descend(Depth0, Depth),
             build_recursive_call_site_cost_map(Deep, CliquePtr, PDPtr,
@@ -368,9 +374,10 @@ proc_dynamic_var_use_info(CliquePtr, PDPtr, ArgNum, RecursionType,
             MaybeVarUseInfo = ok(VarUseInfo)
         ;
             PDPtr = proc_dynamic_ptr(PDNum),
-            MaybeVarUseInfo = error(format(
+            string.format(
                 "proc_dynamic_var_use_info: ArgNum %d out of range for PD %d",
-                [i(ArgNum), i(PDNum)]))
+                [i(ArgNum), i(PDNum)], Msg),
+            MaybeVarUseInfo = error(Msg)
         )
     ;
         MaybeProcrepCoverage = error(Error),
@@ -426,8 +433,8 @@ proc_dynamic_var_use_info(CliquePtr, PDPtr, ArgNum, RecursionType,
     % use information based on how often they are called from that call site.
     %
 :- pred goal_var_first_use(goal_path::in, goal_rep(T)::in,
-    var_first_use_static_info::in(var_first_use_static_info), float::in, 
-    float::out, found_first_use::out) is det 
+    var_first_use_static_info::in(var_first_use_static_info), float::in,
+    float::out, found_first_use::out) is det
     <= goal_annotation_with_coverage(T).
 
 goal_var_first_use(GoalPath, Goal, StaticInfo, !CostSoFar, FoundFirstUse) :-
@@ -440,7 +447,7 @@ goal_var_first_use(GoalPath, Goal, StaticInfo, !CostSoFar, FoundFirstUse) :-
             get_coverage_before(Coverage, 0)
         ;
             VarUseType = StaticInfo ^ fui_var_use_opts ^ vuo_var_use_type,
-            VarUseType = var_use_production, 
+            VarUseType = var_use_production,
             (
                 Detism = erroneous_rep
             ;
@@ -501,8 +508,8 @@ goal_var_first_use(GoalPath, Goal, StaticInfo, !CostSoFar, FoundFirstUse) :-
                 ; AtomicGoal = builtin_call_rep(_, _, _)
                 ),
                 % trivial goals have a zero cost, so !CostSoFar is not updated.
-                atomic_trivial_var_first_use(AtomicGoal, BoundVars, !.CostSoFar,
-                    StaticInfo, FoundFirstUse)
+                atomic_trivial_var_first_use(AtomicGoal, BoundVars,
+                    !.CostSoFar, StaticInfo, FoundFirstUse)
             )
         )
     ),
@@ -517,7 +524,7 @@ goal_var_first_use(GoalPath, Goal, StaticInfo, !CostSoFar, FoundFirstUse) :-
     ;       method_call_rep(ground, ground, ground).
 
 :- pred call_var_first_use(atomic_goal_rep::in(atomic_goal_rep_call),
-    list(var_rep)::in, goal_path::in, 
+    list(var_rep)::in, goal_path::in,
     var_first_use_static_info::in(var_first_use_static_info),
     float::in, float::out, found_first_use::out) is det.
 
@@ -530,9 +537,7 @@ call_var_first_use(AtomicGoal, BoundVars, GoalPath, StaticInfo,
     map.lookup(CostMap, GoalPath, CostAndCallees),
 
     % Get the cost of the call.
-    (
-        cost_and_callees_is_recursive(CliquePtr, CostAndCallees)
-    ->
+    ( cost_and_callees_is_recursive(CliquePtr, CostAndCallees) ->
         map.lookup(RecCostMap, GoalPath, Cost0)
     ;
         Cost0 = CostAndCallees ^ cac_cost
@@ -543,7 +548,7 @@ call_var_first_use(AtomicGoal, BoundVars, GoalPath, StaticInfo,
         Cost = cs_cost_get_percall(Cost0)
     ),
     NextCostSoFar = CostSoFar + Cost,
-    
+
     % Determine if the variable we're searching for uses of is involved with
     % this call.
     (
@@ -555,19 +560,19 @@ call_var_first_use(AtomicGoal, BoundVars, GoalPath, StaticInfo,
         ),
         Vars = [HOVar | Args]
     ),
-    ( member(Var, Vars) ->
-        
+    ( list.member(Var, Vars) ->
         solutions((pred(TimeI::out) is nondet :-
                 (
                     consume_ho_arg(AtomicGoal, Var, TimeI)
                 ;
-                    call_args_first_use(Args, Cost, StaticInfo, 
+                    call_args_first_use(Args, Cost, StaticInfo,
                         CostAndCallees, TimeI)
                 )
             ), Times),
         (
             Times = [],
-            error(this_file ++ ": No solutions for variable first use time")
+            unexpected($module, $pred,
+                "no solutions for variable first use time")
         ;
             Times = [FirstTime | OtherTimes],
             FoundFirstUse = found_first_use(FirstTime + CostSoFar),
@@ -578,21 +583,21 @@ call_var_first_use(AtomicGoal, BoundVars, GoalPath, StaticInfo,
             ->
                 true
             ;
-                error(this_file ++ 
-                    ": Multiple solutions for variable production time")
+                unexpected($module, $pred,
+                    "multiple solutions for variable production time")
             )
         ),
-        
+
         % Assertion
         (
             VarUseType = var_use_production
         =>
-            member(Var, BoundVars)
+            list.member(Var, BoundVars)
         ->
             true
         ;
-            error(this_file ++ 
-                ": A bound var must be produced by a call if it's an argument.")
+            unexpected($module, $pred,
+                "a bound var must be produced by a call if it is an argument.")
         ),
         (
             VarUseType = var_use_consumption
@@ -601,8 +606,8 @@ call_var_first_use(AtomicGoal, BoundVars, GoalPath, StaticInfo,
         ->
             true
         ;
-            error(this_file ++
-                ": A consumed var must not be mentioned in BoundVars.")
+            unexpected($module, $pred,
+                "a consumed var must not be mentioned in BoundVars")
         ),
         (
             VarUseType = var_use_production
@@ -615,8 +620,8 @@ call_var_first_use(AtomicGoal, BoundVars, GoalPath, StaticInfo,
         ->
             true
         ;
-            error(this_file ++ 
-                ": A HO call site cannot produce it's own HO value.")
+            unexpected($module, $pred,
+                "a HO call site cannot produce its own HO value")
         )
     ;
         FoundFirstUse = have_not_found_first_use
@@ -628,8 +633,8 @@ call_var_first_use(AtomicGoal, BoundVars, GoalPath, StaticInfo,
 consume_ho_arg(higher_order_call_rep(Var, _), Var, 0.0).
 consume_ho_arg(method_call_rep(Var, _, _), Var, 0.0).
 
-:- pred call_args_first_use(list(var_rep)::in, float::in, 
-    var_first_use_static_info::in(var_first_use_static_info), 
+:- pred call_args_first_use(list(var_rep)::in, float::in,
+    var_first_use_static_info::in(var_first_use_static_info),
     cost_and_callees::in, float::out) is nondet.
 
 call_args_first_use(Args, Cost, StaticInfo, CostAndCallees, Time) :-
@@ -638,7 +643,7 @@ call_args_first_use(Args, Cost, StaticInfo, CostAndCallees, Time) :-
     VarUseType = VarUseOptions ^ vuo_var_use_type,
     HigherOrder = CostAndCallees ^ cac_call_site_is_ho,
     Callees = CostAndCallees ^ cac_callees,
-    member_index0(Var, Args, ArgNum), 
+    member_index0(Var, Args, ArgNum),
     (
         HigherOrder = first_order_call,
         ( empty(Callees) ->
@@ -657,8 +662,8 @@ call_args_first_use(Args, Cost, StaticInfo, CostAndCallees, Time) :-
                 pessimistic_var_use_time(VarUseType, Cost, Time)
             )
         ;
-            error(this_file ++ 
-                "Wrong number of callees for normal call site")
+            unexpected($module, $pred,
+                "wrong number of callees for normal call site")
         )
     ;
         HigherOrder = higher_order_call,
@@ -710,9 +715,9 @@ atomic_trivial_var_first_use(AtomicGoal, BoundVars, CostSoFar, StaticInfo,
     % an execution order, namely disjunctions and if-then-elses.
     %
 :- pred conj_var_first_use(goal_path::in, int::in,
-    list(goal_rep(T))::in, 
+    list(goal_rep(T))::in,
     var_first_use_static_info::in(var_first_use_static_info),
-    float::in, float::out, found_first_use::out) is det 
+    float::in, float::out, found_first_use::out) is det
     <= goal_annotation_with_coverage(T).
 
 conj_var_first_use(_, _, [], _, !Cost, have_not_found_first_use).
@@ -736,7 +741,7 @@ conj_var_first_use(GoalPath, ConjNum, [Conj | Conjs], StaticInfo, !CostSoFar,
     ).
 
 :- pred disj_var_first_use(goal_path::in, list(goal_rep(T))::in,
-    detism_rep::in, var_first_use_static_info::in(var_first_use_static_info), 
+    detism_rep::in, var_first_use_static_info::in(var_first_use_static_info),
     float::in, float::out, found_first_use::out) is det
     <= goal_annotation_with_coverage(T).
 
@@ -814,7 +819,8 @@ disj_var_first_use_2(GoalPath, DisjNum, [Disj | Disjs], StaticInfo, !CostSoFar,
             ( get_coverage_before(get_coverage(Disj), HeadCount) ->
                 HeadWeight = float(HeadCount)
             ;
-                error(this_file ++ " unknown coverage before disjunct")
+                unexpected($module, $pred,
+                    "unknown coverage before disjunct")
             ),
             (
                 Disjs = [],
@@ -825,7 +831,8 @@ disj_var_first_use_2(GoalPath, DisjNum, [Disj | Disjs], StaticInfo, !CostSoFar,
                 ( get_coverage_before(FirstTailCoverage, TailCount) ->
                     TailWeight = float(TailCount)
                 ;
-                    error(this_file ++ " unknown coverage before disjunct")
+                    unexpected($module, $pred,
+                        "unknown coverage before disjunct")
                 )
             ),
             weighted_average([HeadWeight, TailWeight], [HeadCost, TailCost],
@@ -834,8 +841,8 @@ disj_var_first_use_2(GoalPath, DisjNum, [Disj | Disjs], StaticInfo, !CostSoFar,
         FoundFirstUse = found_first_use(Cost)
     ).
 
-:- pred switch_var_first_use(goal_path::in, var_rep::in, 
-    list(case_rep(T))::in, 
+:- pred switch_var_first_use(goal_path::in, var_rep::in,
+    list(case_rep(T))::in,
     var_first_use_static_info::in(var_first_use_static_info),
     float::in, float::out, found_first_use::out) is det
     <= goal_annotation_with_coverage(T).
@@ -872,8 +879,8 @@ switch_var_first_use(GoalPath, SwitchedOnVar, Cases, StaticInfo,
     ).
 
 :- pred switch_var_first_use_2(goal_path::in, int::in,
-    var_first_use_static_info::in(var_first_use_static_info), 
-    list(case_rep(T))::in, list(float)::out, float::in, 
+    var_first_use_static_info::in(var_first_use_static_info),
+    list(case_rep(T))::in, list(float)::out, float::in,
     list(float)::out, list(found_first_use)::out)
     is det <= goal_annotation_with_coverage(T).
 
@@ -890,10 +897,11 @@ switch_var_first_use_2(GoalPath, CaseNum, StaticInfo, [Case | Cases],
     ( get_coverage_before(get_coverage(Goal), BeforeCount) ->
         Weight = float(BeforeCount)
     ;
-        error(this_file ++ "unknown coverage before switch case")
+        unexpected($module, $pred, "unknown coverage before switch case")
     ).
 
-:- pred ite_var_first_use(goal_path::in, 
+/* ###  Error: no clauses for predicate `ite_var_first_use'/8. */
+:- pred ite_var_first_use(goal_path::in,
     goal_rep(T)::in, goal_rep(T)::in, goal_rep(T)::in,
     var_first_use_static_info::in(var_first_use_static_info),
     float::in, float::out, found_first_use::out)
@@ -907,8 +915,8 @@ ite_var_first_use(GoalPath, Cond, Then, Else, StaticInfo,
     ->
         Weights = [float(CountBeforeThen), float(CountBeforeElse)]
     ;
-        error(this_file ++
-            "incomplete coverage information for if then else branches")
+        unexpected($module, $pred,
+            "incomplete coverage information for if-then-else branches")
     ),
     CondGoalPath = goal_path_add_at_end(GoalPath, step_ite_cond),
     ThenGoalPath = goal_path_add_at_end(GoalPath, step_ite_then),
@@ -950,8 +958,9 @@ ite_var_first_use(GoalPath, Cond, Then, Else, StaticInfo,
                 VarUseTime),
             FoundFirstUse = found_first_use(VarUseTime),
             trace [compile_time(flag("debug_first_var_use")), io(!IO)] (
-                io.format("Trace: ITE: Weights: %s, Then: %f, Else: %f, " ++
-                        "VarUseTime: %f\n",
+                io.format(
+                    "Trace: ITE: Weights: %s, Then: %f, Else: %f, " ++
+                    "VarUseTime: %f\n",
                     [s(string(Weights)), f(ThenVarUseTime), f(ElseVarUseTime),
                         f(VarUseTime)],
                     !IO)
@@ -966,10 +975,10 @@ ffu_to_float(_, found_first_use(CostBeforeUse), CostBeforeUse).
 
 %----------------------------------------------------------------------------%
 
-:- pred goal_var_first_use_wrapper(clique_ptr::in, set(proc_dynamic_ptr)::in, 
-    map(goal_path, cost_and_callees)::in, map(goal_path, cs_cost_csq)::in, 
+:- pred goal_var_first_use_wrapper(clique_ptr::in, set(proc_dynamic_ptr)::in,
+    map(goal_path, cost_and_callees)::in, map(goal_path, cs_cost_csq)::in,
     recursion_type::in(recursion_type_known_costs), recursion_depth::in,
-    goal_rep(coverage_info)::in, float::in, var_rep::in, 
+    goal_rep(coverage_info)::in, float::in, var_rep::in,
     var_use_options::in, var_use_info::out) is det.
 
 goal_var_first_use_wrapper(CliquePtr, CallStack, CallSiteMap,
@@ -984,14 +993,14 @@ goal_var_first_use_wrapper(CliquePtr, CallStack, CallSiteMap,
         VarUseInfo).
 
 :- instance goal_annotation_with_coverage(coverage_info) where [
-        (get_coverage(Goal) = Goal ^ goal_annotation)
-    ].
+    (get_coverage(Goal) = Goal ^ goal_annotation)
+].
 
 var_first_use(CliquePtr, CallSiteMap, RecursiveCallSiteMap, RT, CurDepth,
         Goal, GoalPath, Cost, Var, VarUseOptions, VarUseInfo) :-
     goal_var_first_use(GoalPath, Goal,
         var_first_use_static_info(CliquePtr, CallSiteMap, RecursiveCallSiteMap,
-            Var, VarUseOptions, set.init, RT, CurDepth), 
+            Var, VarUseOptions, set.init, RT, CurDepth),
         0.0, _, FoundFirstUse),
     VarUseType = VarUseOptions ^ vuo_var_use_type,
     found_first_use_to_use_info(FoundFirstUse, Cost, VarUseType, VarUseInfo).
@@ -1012,8 +1021,8 @@ found_first_use_to_use_info(FoundFirstUse, Cost, VarUseType, VarUseInfo) :-
         %     performed.
         (
             VarUseType = var_use_production,
-            error(this_file ++ 
-                ": Goal did not produce a variable that it should have")
+            unexpected($module, $pred,
+                "goal did not produce a variable that it should have")
         ;
             VarUseType = var_use_consumption,
             VarUseInfo = var_use_info(Cost, Cost, VarUseType)
@@ -1047,9 +1056,3 @@ intermodule_var_use_should_follow_call(VarUseOptions, CSDPtr) :-
     ).
 
 %-----------------------------------------------------------------------------%
-
-:- func this_file = string.
-
-this_file = "var_use_analysis.m".
-
-%-----------------------------------------------------------------------------%
diff --git a/library/require.m b/library/require.m
index c89cc49a8..b00f89c7a 100644
--- a/library/require.m
+++ b/library/require.m
@@ -1,17 +1,17 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et wm=0 tw=0
 %-----------------------------------------------------------------------------%
-% Copyright (C) 1993-1999, 2003, 2005-2006 The University of Melbourne.
+% Copyright (C) 1993-1999, 2003, 2005-2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU Library General
 % Public License - see the file COPYING.LIB in the Mercury distribution.
 %-----------------------------------------------------------------------------%
-% 
+%
 % File: require.m.
 % Main author: fjh.
 % Stability: medium to high.
-% 
+%
 % This module provides features similar to <assert.h> in C.
-% 
+%
 %-----------------------------------------------------------------------------%
 %-----------------------------------------------------------------------------%
 
@@ -32,39 +32,93 @@
     %
 :- func func_error(string) = _ is erroneous.
 
+%-----------------------------------------------------------------------------%
+
+    % sorry(Module, What):
+    %
+    % Call error/1 with the string
+    % "Module: Sorry, not implemented: What".
+    %
+    % Use this for features that should be implemented (or at least could be
+    % implemented).
+    %
+:- func sorry(string, string) = _ is erroneous.
+:- pred sorry(string::in, string::in) is erroneous.
+
+    % sorry(Module, Proc What):
+    %
+    % Call error/1 with the string
+    % "Module: Proc: Sorry, not implemented: What".
+    %
+    % Use this for features that should be implemented,
+    % or at least could be implemented.
+    %
+:- func sorry(string, string, string) = _ is erroneous.
+:- pred sorry(string::in, string::in, string::in) is erroneous.
+
+    % unexpected(Module, Message):
+    %
+    % Call error/1 with the string
+    % "Module: Unexpected: What".
+    %
+    % Use this to handle cases which are not expected to arise (i.e. bugs).
+    %
+:- func unexpected(string, string) = _ is erroneous.
+:- pred unexpected(string::in, string::in) is erroneous.
+
+    % unexpected(Module, Proc, Message):
+    %
+    % Call error/1 with the string
+    % "Module: Proc: Unexpected: What".
+    %
+    % Use this to handle cases which are not expected to arise (i.e. bugs).
+    %
+:- func unexpected(string, string, string) = _ is erroneous.
+:- pred unexpected(string::in, string::in, string::in) is erroneous.
+
+%-----------------------------------------------------------------------------%
+
     % require(Goal, Message):
     %
     % Call goal, and call error(Message) if Goal fails.
     % This is not as useful as you might imagine, since it requires
-    % that the goal not produce any output variables.  In
-    % most circumstances you should use an explicit if-then-else
-    % with a call to error/1 in the "else".
+    % that the goal not produce any output variables. In most circumstances,
+    % you should use an explicit if-then-else with a call to error/1,
+    % or one of its wrappers, in the "else".
     %
 :- pred require((pred)::((pred) is semidet), string::in) is det.
 
-    % report_lookup_error(Message, Key, Value):
+    % expect(Goal, Module, Message):
     %
-    % Call error/1 with an error message that is appropriate for
-    % the failure of a lookup operation involving the specified
-    % Key and Value.  The error message will include Message
-    % and information about Key and Value.
+    % Call Goal, and call unexpected(Module, Message) if Goal fails.
     %
-:- pred report_lookup_error(string::in, K::in, V::unused) is erroneous.
+:- pred expect((pred)::((pred) is semidet), string::in, string::in) is det.
+
+%-----------------------------------------------------------------------------%
 
     % report_lookup_error(Message, Key):
     %
     % Call error/1 with an error message that is appropriate for
-    % the failure of a lookup operation involving the specified
-    % Key.  The error message will include Message
-    % and information about Key.
+    % the failure of a lookup operation involving the specified Key.
+    % The error message will include Message and information about Key.
     %
 :- pred report_lookup_error(string::in, K::in) is erroneous.
 
+    % report_lookup_error(Message, Key, Value):
+    %
+    % Call error/1 with an error message that is appropriate for
+    % the failure of a lookup operation involving the specified Key and Value.
+    % The error message will include Message and information about Key
+    % and Value.
+    %
+:- pred report_lookup_error(string::in, K::in, V::unused) is erroneous.
+
 %-----------------------------------------------------------------------------%
 %-----------------------------------------------------------------------------%
 
 :- implementation.
 
+% :- import_module bool.
 :- import_module exception.
 :- import_module list.
 :- import_module string.
@@ -72,45 +126,6 @@
 
 %-----------------------------------------------------------------------------%
 
-require(Goal, Message) :-
-    ( call(Goal) ->
-        true
-    ;
-        error(Message),
-        fail
-    ).
-
-%-----------------------------------------------------------------------------%
-
-report_lookup_error(Msg, K, V) :-
-    KeyType = type_name(type_of(K)),
-    ValueType = type_name(type_of(V)),
-    string.append_list(
-        [Msg,
-        "\n\tKey Type: ",
-        KeyType,
-        "\n\tKey Value: ",
-        string(K),
-        "\n\tValue Type: ",
-        ValueType
-        ],
-        ErrorString),
-    error(ErrorString).
-
-report_lookup_error(Msg, K) :-
-    KeyType = type_name(type_of(K)),
-    string.append_list(
-        [Msg,
-        "\n\tKey Type: ",
-        KeyType,
-        "\n\tKey Value: ",
-        string(K)
-        ],
-        ErrorString),
-    error(ErrorString).
-
-%-----------------------------------------------------------------------------%
-
 % Hopefully error/1 won't be called often (!), so no point inlining it.
 :- pragma no_inline(error/1).
 
@@ -127,6 +142,81 @@ error(Message) :-
 func_error(Message) = _ :-
     error(Message).
 
+%-----------------------------------------------------------------------------%
+
+sorry(Module, What) = _ :-
+    sorry(Module, What).
+sorry(Module, Proc, What) = _ :-
+    sorry(Module, Proc, What).
+
+sorry(Module, What) :-
+    string.format("%s: Sorry, not implemented: %s",
+        [s(Module), s(What)], ErrorMessage),
+    error(ErrorMessage).
+sorry(Module, Proc, What) :-
+    string.format("%s: %s: Sorry, not implemented: %s",
+        [s(Module), s(Proc), s(What)], ErrorMessage),
+    error(ErrorMessage).
+
+unexpected(Module, What) = _ :-
+    unexpected(Module, What).
+unexpected(Module, Proc, What) = _ :-
+    unexpected(Module, Proc, What).
+
+unexpected(Module, What) :-
+    string.format("%s: Unexpected: %s", [s(Module), s(What)], ErrorMessage),
+    error(ErrorMessage).
+unexpected(Module, Proc, What) :-
+    string.format("%s: %s: Unexpected: %s", [s(Module), s(Proc), s(What)],
+        ErrorMessage),
+    error(ErrorMessage).
+
+%-----------------------------------------------------------------------------%
+
+require(Goal, Message) :-
+    ( call(Goal) ->
+        true
+    ;
+        error(Message),
+        fail
+    ).
+
+expect(Goal, Module, Message) :-
+    ( Goal ->
+        true
+    ;
+        unexpected(Module, Message)
+    ).
+
+%-----------------------------------------------------------------------------%
+
+report_lookup_error(Msg, K) :-
+    KeyType = type_name(type_of(K)),
+    string.append_list(
+        [Msg,
+        "\n\tKey Type: ",
+        KeyType,
+        "\n\tKey Value: ",
+        string(K)
+        ],
+        ErrorString),
+    error(ErrorString).
+
+report_lookup_error(Msg, K, V) :-
+    KeyType = type_name(type_of(K)),
+    ValueType = type_name(type_of(V)),
+    string.append_list(
+        [Msg,
+        "\n\tKey Type: ",
+        KeyType,
+        "\n\tKey Value: ",
+        string(K),
+        "\n\tValue Type: ",
+        ValueType
+        ],
+        ErrorString),
+    error(ErrorString).
+
 %-----------------------------------------------------------------------------%
 :- end_module require.
 %-----------------------------------------------------------------------------%
diff --git a/mdbcomp/feedback.automatic_parallelism.m b/mdbcomp/feedback.automatic_parallelism.m
index ad891f2d2..b94e0a71e 100644
--- a/mdbcomp/feedback.automatic_parallelism.m
+++ b/mdbcomp/feedback.automatic_parallelism.m
@@ -130,7 +130,7 @@
                 % A variable name table for the variables that have
                 % sensible names.
                 cpcp_var_table  :: var_table,
-                                        
+
                 cpcp_par_conjs  :: list(candidate_par_conjunction(GoalType))
             ).
 
@@ -189,11 +189,11 @@
 :- type callee_rep
     --->    unknown_callee
             % An unknown callee such as a higher order or method call.
-                
+
     ;       named_callee(
                 % A known callee. Note that arity and mode are not stored at
                 % all. XXX why?
-               
+
                 nc_module_name  :: string,
                 nc_proc_name    :: string
             ).
@@ -209,7 +209,7 @@
                 pga_cost_percall            :: float,
 
                 pga_coat_above_threshold    :: cost_above_par_threshold,
-            
+
                 % Variable use information.
                 pga_var_productions         :: assoc_list(var_rep, float),
                 pga_var_consumptions        :: assoc_list(var_rep, float)
@@ -230,17 +230,17 @@
     ;       conjuncts_are_independent.
 
 :- pred convert_candidate_par_conjunctions_proc(
-    pred(candidate_par_conjunction(A), A, B)::in(pred(in, in, out) is det), 
+    pred(candidate_par_conjunction(A), A, B)::in(pred(in, in, out) is det),
     candidate_par_conjunctions_proc(A)::in,
     candidate_par_conjunctions_proc(B)::out) is det.
 
 :- pred convert_candidate_par_conjunction(
-    pred(candidate_par_conjunction(A), A, B)::in(pred(in, in, out) is det), 
+    pred(candidate_par_conjunction(A), A, B)::in(pred(in, in, out) is det),
     candidate_par_conjunction(A)::in, candidate_par_conjunction(B)::out)
     is det.
 
 :- pred convert_seq_conj(
-    pred(A, B)::in(pred(in, out) is det), 
+    pred(A, B)::in(pred(in, out) is det),
     seq_conj(A)::in, seq_conj(B)::out) is det.
 
 %-----------------------------------------------------------------------------%
@@ -281,7 +281,7 @@
     % means that the goal is twice as fast when parallelised.
     %
 :- func parallel_exec_metrics_get_speedup(parallel_exec_metrics) = float.
-    
+
     % The amount of time saved per-call: SeqTime - ParTime.
     %
 :- func parallel_exec_metrics_get_time_saving(parallel_exec_metrics) = float.
diff --git a/mdbcomp/mdbcomp.m b/mdbcomp/mdbcomp.m
index 5ed5580ff..1665f7a6c 100644
--- a/mdbcomp/mdbcomp.m
+++ b/mdbcomp/mdbcomp.m
@@ -1,7 +1,7 @@
 %---------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et wm=0 tw=0
 %---------------------------------------------------------------------------%
-% Copyright (C) 2003, 2005-2006 The University of Melbourne.
+% Copyright (C) 2003, 2005-2006, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU Library General
 % Public License - see the file COPYING.LIB in the Mercury distribution.
 %---------------------------------------------------------------------------%
@@ -22,7 +22,7 @@
 
 :- pred mdbcomp.version(string::out) is det.
 
-% If you add any modules here, you should update the lists in 
+% If you add any modules here, you should update the lists in
 % deep_profiler/Mmakefile and slice/Mmakefile.
 :- include_module feedback.
 :- include_module prim_data.
diff --git a/mdbcomp/trace_counts.m b/mdbcomp/trace_counts.m
index bf9ee00e0..95139856c 100644
--- a/mdbcomp/trace_counts.m
+++ b/mdbcomp/trace_counts.m
@@ -1,7 +1,7 @@
 %-----------------------------------------------------------------------------%
 % vim: ft=mercury ts=4 sw=4 et wm=0 tw=0
 %-----------------------------------------------------------------------------%
-% Copyright (C) 2005-2008 The University of Melbourne.
+% Copyright (C) 2005-2008, 2010 The University of Melbourne.
 % This file may only be copied under the terms of the GNU General
 % Public License - see the file COPYING in the Mercury distribution.
 %-----------------------------------------------------------------------------%
@@ -995,4 +995,3 @@ insert_into_list_as_set(List0, Item) = List :-
     set.list_to_set(List0, Set0),
     set.insert(Set0, Item, Set),
     set.to_sorted_list(Set, List).
-