Files
mercury/compiler/code_aux.m
Thomas Conway 5c955626f2 These changes make var' and term' polymorphic.
Estimated hours taken: 20

These changes make `var' and `term' polymorphic. This allows us to make
variables and terms representing types of a different type to those
representing program terms and those representing insts.

These changes do not *fix* any existing problems (for instance
there was a messy conflation of program variables and inst variables,
and where necessary I've just called varset__init(InstVarSet) with
an XXX comment).

NEWS:
	Mention the changes to the standard library.

library/term.m:
	Make term, var and var_supply polymorphic.
	Add new predicates:
		term__generic_term/1
		term__coerce/2
		term__coerce_var/2
		term__coerce_var_supply/2

library/varset.m:
	Make varset polymorphic.
	Add the new predicate:
		varset__coerce/2

compiler/prog_data.m:
	Introduce type equivalences for the different kinds of
	vars, terms, and varsets that we use (tvar and tvarset
	were already there but have been changed to use the
	polymorphic var and term).

	Also change the various kinds of items to use the appropriate
	kinds of var/varset.

compiler/*.m:
	Thousands of boring changes to make the compiler type correct
	with the different types for type, program and inst vars and
	varsets.
1998-11-20 04:10:36 +00:00

253 lines
9.1 KiB
Mathematica

%-----------------------------------------------------------------------------%
% Copyright (C) 1994-1998 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.
%---------------------------------------------------------------------------%
%
% Auxiliary code generator module. Unlike code_util, it imports code_info.
%
% Main authors: conway, zs.
%
%---------------------------------------------------------------------------%
%---------------------------------------------------------------------------%
:- module code_aux.
:- interface.
:- import_module code_info, hlds_module, hlds_goal, prog_data.
:- import_module bool.
% code_aux__contains_only_builtins(G) is true if G is a leaf procedure,
% i.e. control does not leave G to call another procedure, even if
% that procedure is a complicated unification.
:- pred code_aux__contains_only_builtins(hlds_goal).
:- mode code_aux__contains_only_builtins(in) is semidet.
% Succeeds if the goal cannot loop or call error/1.
:- pred code_aux__goal_cannot_loop(module_info, hlds_goal).
:- mode code_aux__goal_cannot_loop(in, in) is semidet.
% code_aux__goal_is_flat(Goal) is true if Goal does not contain
% any branched structures (ie if-then-else or disjunctions or
% switches.)
:- pred code_aux__goal_is_flat(hlds_goal).
:- mode code_aux__goal_is_flat(in) is semidet.
% code_aux__contains_simple_recursive_call(G, CI, Last) succeeds
% if G is a conjunction of goals, exactly one of which is a recursive
% call (CI says what the current procedure is), and there are no
% other goals that cause control to leave this procedure. Last is
% set dependening on whether the recursive call is last in the
% conjunction or not.
:- pred code_aux__contains_simple_recursive_call(hlds_goal, code_info, bool).
:- mode code_aux__contains_simple_recursive_call(in, in, out) is semidet.
:- pred code_aux__explain_stack_slots(stack_slots, prog_varset, string).
:- mode code_aux__explain_stack_slots(in, in, out) is det.
%---------------------------------------------------------------------------%
:- implementation.
:- import_module hlds_pred, llds, llds_out, varset, type_util, term_util.
:- import_module string, set, std_util, assoc_list, require.
:- import_module list, map.
code_aux__contains_only_builtins(Goal - _GoalInfo) :-
code_aux__contains_only_builtins_2(Goal).
:- pred code_aux__contains_only_builtins_2(hlds_goal_expr).
:- mode code_aux__contains_only_builtins_2(in) is semidet.
code_aux__contains_only_builtins_2(conj(Goals)) :-
code_aux__contains_only_builtins_list(Goals).
code_aux__contains_only_builtins_2(disj(Goals, _)) :-
code_aux__contains_only_builtins_list(Goals).
code_aux__contains_only_builtins_2(switch(_Var, _Category, Cases, _)) :-
code_aux__contains_only_builtins_cases(Cases).
code_aux__contains_only_builtins_2(not(Goal)) :-
code_aux__contains_only_builtins(Goal).
code_aux__contains_only_builtins_2(some(_Vars, Goal)) :-
code_aux__contains_only_builtins(Goal).
code_aux__contains_only_builtins_2(if_then_else(_Vars, Cond, Then, Else, _)) :-
code_aux__contains_only_builtins(Cond),
code_aux__contains_only_builtins(Then),
code_aux__contains_only_builtins(Else).
code_aux__contains_only_builtins_2(call(_, _, _, BuiltinState, _, _)) :-
BuiltinState = inline_builtin.
code_aux__contains_only_builtins_2(unify(_, _, _, Uni, _)) :-
(
Uni = assign(_, _)
;
Uni = simple_test(_, _)
;
Uni = construct(_, _, _, _)
;
Uni = deconstruct(_, _, _, _, _)
).
% Complicated unifies are _non_builtin_
:- pred code_aux__contains_only_builtins_cases(list(case)).
:- mode code_aux__contains_only_builtins_cases(in) is semidet.
code_aux__contains_only_builtins_cases([]).
code_aux__contains_only_builtins_cases([case(_ConsId, Goal)|Cases]) :-
code_aux__contains_only_builtins(Goal),
code_aux__contains_only_builtins_cases(Cases).
:- pred code_aux__contains_only_builtins_list(list(hlds_goal)).
:- mode code_aux__contains_only_builtins_list(in) is semidet.
code_aux__contains_only_builtins_list([]).
code_aux__contains_only_builtins_list([Goal|Goals]) :-
code_aux__contains_only_builtins(Goal),
code_aux__contains_only_builtins_list(Goals).
%-----------------------------------------------------------------------------%
code_aux__goal_cannot_loop(ModuleInfo, Goal) :-
Goal = GoalExpr - _,
code_aux__goal_cannot_loop_2(ModuleInfo, GoalExpr).
:- pred code_aux__goal_cannot_loop_2(module_info, hlds_goal_expr).
:- mode code_aux__goal_cannot_loop_2(in, in) is semidet.
code_aux__goal_cannot_loop_2(ModuleInfo, conj(Goals)) :-
\+ (
list__member(Goal, Goals),
\+ code_aux__goal_cannot_loop(ModuleInfo, Goal)
).
code_aux__goal_cannot_loop_2(ModuleInfo, disj(Goals, _)) :-
\+ (
list__member(Goal, Goals),
\+ code_aux__goal_cannot_loop(ModuleInfo, Goal)
).
code_aux__goal_cannot_loop_2(ModuleInfo, switch(_Var, _Category, Cases, _)) :-
\+ (
list__member(Case, Cases),
Case = case(_, Goal),
\+ code_aux__goal_cannot_loop(ModuleInfo, Goal)
).
code_aux__goal_cannot_loop_2(ModuleInfo, not(Goal)) :-
code_aux__goal_cannot_loop(ModuleInfo, Goal).
code_aux__goal_cannot_loop_2(ModuleInfo, some(_Vars, Goal)) :-
code_aux__goal_cannot_loop(ModuleInfo, Goal).
code_aux__goal_cannot_loop_2(ModuleInfo,
if_then_else(_Vars, Cond, Then, Else, _)) :-
code_aux__goal_cannot_loop(ModuleInfo, Cond),
code_aux__goal_cannot_loop(ModuleInfo, Then),
code_aux__goal_cannot_loop(ModuleInfo, Else).
code_aux__goal_cannot_loop_2(ModuleInfo, call(PredId, ProcId, _, _, _, _)) :-
module_info_pred_proc_info(ModuleInfo, PredId, ProcId, _, ProcInfo),
proc_info_get_maybe_termination_info(ProcInfo, MaybeTermInfo),
MaybeTermInfo = yes(cannot_loop).
code_aux__goal_cannot_loop_2(_, unify(_, _, _, Uni, _)) :-
(
Uni = assign(_, _)
;
Uni = simple_test(_, _)
;
Uni = construct(_, _, _, _)
;
Uni = deconstruct(_, _, _, _, _)
).
% Complicated unifies are _non_builtin_
%-----------------------------------------------------------------------------%
code_aux__goal_is_flat(Goal - _GoalInfo) :-
code_aux__goal_is_flat_2(Goal).
:- pred code_aux__goal_is_flat_2(hlds_goal_expr).
:- mode code_aux__goal_is_flat_2(in) is semidet.
code_aux__goal_is_flat_2(conj(Goals)) :-
code_aux__goal_is_flat_list(Goals).
code_aux__goal_is_flat_2(not(Goal)) :-
code_aux__goal_is_flat(Goal).
code_aux__goal_is_flat_2(some(_Vars, Goal)) :-
code_aux__goal_is_flat(Goal).
code_aux__goal_is_flat_2(higher_order_call(_, _, _, _, _, _)).
code_aux__goal_is_flat_2(call(_, _, _, _, _, _)).
code_aux__goal_is_flat_2(unify(_, _, _, _, _)).
code_aux__goal_is_flat_2(pragma_c_code(_, _, _, _, _, _, _)).
%-----------------------------------------------------------------------------%
:- pred code_aux__goal_is_flat_list(list(hlds_goal)).
:- mode code_aux__goal_is_flat_list(in) is semidet.
code_aux__goal_is_flat_list([]).
code_aux__goal_is_flat_list([Goal|Goals]) :-
code_aux__goal_is_flat(Goal),
code_aux__goal_is_flat_list(Goals).
%-----------------------------------------------------------------------------%
code_aux__contains_simple_recursive_call(Goal - _, CodeInfo, Last) :-
Goal = conj(Goals),
code_aux__contains_simple_recursive_call_2(Goals, CodeInfo, Last).
:- pred code_aux__contains_simple_recursive_call_2(list(hlds_goal), code_info,
bool).
:- mode code_aux__contains_simple_recursive_call_2(in, in, out) is semidet.
code_aux__contains_simple_recursive_call_2([Goal|Goals], CodeInfo, Last) :-
Goal = GoalExpr - _,
(
code_aux__contains_only_builtins_2(GoalExpr)
->
code_aux__contains_simple_recursive_call_2(Goals, CodeInfo,
Last)
;
code_aux__is_recursive_call(GoalExpr, CodeInfo),
( Goals = [] ->
Last = yes
;
code_aux__contains_only_builtins_list(Goals),
Last = no
)
).
:- pred code_aux__is_recursive_call(hlds_goal_expr, code_info).
:- mode code_aux__is_recursive_call(in, in) is semidet.
code_aux__is_recursive_call(Goal, CodeInfo) :-
Goal = call(CallPredId, CallProcId, _, BuiltinState, _, _),
BuiltinState = not_builtin,
code_info__get_pred_id(PredId, CodeInfo, _),
PredId = CallPredId,
code_info__get_proc_id(ProcId, CodeInfo, _),
ProcId = CallProcId.
%-----------------------------------------------------------------------------%
code_aux__explain_stack_slots(StackSlots, VarSet, Explanation) :-
map__to_assoc_list(StackSlots, StackSlotsList),
code_aux__explain_stack_slots_2(StackSlotsList, VarSet, "",
Explanation1),
string__append("\nStack slot assignments (if any):\n", Explanation1,
Explanation).
:- pred code_aux__explain_stack_slots_2(assoc_list(prog_var, lval), prog_varset,
string, string).
:- mode code_aux__explain_stack_slots_2(in, in, in, out) is det.
code_aux__explain_stack_slots_2([], _, String, String).
code_aux__explain_stack_slots_2([Var - Lval | Rest], VarSet, String0, String) :-
code_aux__explain_stack_slots_2(Rest, VarSet, String0, String1),
( llds_out__lval_to_string(Lval, LvalString0) ->
LvalString = LvalString0
;
LvalString = "some lval"
),
varset__lookup_name(VarSet, Var, VarName),
string__append_list([VarName, "\t ->\t", LvalString, "\n", String1],
String).
%---------------------------------------------------------------------------%