Commit Graph

88 Commits

Author SHA1 Message Date
Zoltan Somogyi
a2cdba85bd Reduce duplication of code about int type names.
compiler/prog_data.m:
    Give two predicates dealing with the names of builtin types
    more meaningful names. Document the semantics of both predicates,
    and document the reason why the definition of one is effectively
    inlined into the definition of the other.

compiler/builtin_ops.m:
    Make a copy of one of the predicates easier to read, even though
    the copy cannot be replaced by a call.

compiler/module_qual.qualify_items.m:
    Do replace such copy by a call.

compiler/error_type_util.m:
compiler/parse_tree_out_type.m:
compiler/parse_tree_to_term.m:
compiler/pred_name.m:
compiler/prog_event.m:
compiler/prog_type.m:
compiler/table_gen.m:
compiler/typecheck_errors.m:
compiler/xml_documentation.m:
    Refer to the predicates by their new names.
2023-05-21 11:33:20 +10:00
Zoltan Somogyi
a47de48c4d s/input_stream/text_input_stream/ ...
... and the same for output streams.
2023-04-24 14:59:20 +10:00
Zoltan Somogyi
18817d62d0 Record more than a pred_proc_id for each method.
Class and instance definitions both contain lists of methods,
predicates and/or functions, that each have one or more procedures.
Until now, we represented the methods in class and instance definitions
as lists of nothing more than pred_proc_ids. This fact complicated
several operations,

- partly because there was no simple way to tell which procedures
  were part of the same predicate or function, and

- partly because the order of the list is important (we identify
  each method procedure in our equivalent of vtables with a number,
  which is simply the procedure's position in this list), but there was
  absolutely no information about recorded about this.

This diff therefore replaces the lists of pred_proc_ids with lists of
method_infos. Each method_info contains

- the method procedure number, i.e. the vtable index,

- the pred_or_func, sym_name and user arity of the predicate or function
  that the method procedure is a part of, to make it simple to test
  whether two method_infos represent different modes of the same predicate
  or function, or not,

- the original pred_proc_id of the method procedure, which never changes,
  and

- the current pred_proc_id, which program transformations *can* change.

compiler/hlds_class.m:
    Make the change above in the representations of class and instance
    definitions.

    Put the fields of both types into a better order, by putting
    related fields next to each other.

    Put a notag wrapper around method procedure numbers to prevent
    accidentally mixing them up with plain integers.

    Add some utility functions.

compiler/prog_data.m:
    Replace three fields containing pred_or_func, sym_name and arity
    in the parse tree representation of instance methods with just one,
    which contains all three pieces of info. This makes it easier to operate
    on them as a unit.

    Change the representation of methods defined by clauses from a list
    of clauses to a cord of clauses, since this supports constant-time
    append.

compiler/hlds_goal.m:
    Switch from plain ints to the new notag representation of method
    procedure numbers in method call goals.

compiler/add_class.m:
    Simplify the code for adding new classes to the HLDS.

    Give some predicates better names.

compiler/check_typeclass.m:
    Significantly simplify the code for that generates the pred_infos and
    proc_infos implementing all the methods of an instances definition,
    and construct lists of method_infos instead of lists of pred_proc_ids.

    Give some predicates better names.

    Some error messages about problems in instance definitions started with

        In instance declaration for class/arity:

    while others started with

        In instance declaration for class(module_a.foo, module_b.bar):

    Replace both with

        In instance declaration for class(foo, bar):

    because it contains more useful information than the first, and less
    non-useful information than the second. Improve the wording of some
    error messages.

    Factor out some common code.

compiler/prog_mode.m:
compiler/prog_type.m:
compiler/prog_util.m:
    Generalize the existing predicates for stripping "builtin.m" module
    qualifiers from sym_names, cons_ids, insts, types and modes
    to allow also the stripping of *all* module qualifiers. This capability
    is now used when we print an instance's type vector as a context
    for diagnostics about problems inside instance definitions.

compiler/add_pred.m:
    Add a mechanism for returning the pred_id of a newly created pred_info,
    whether or not it was declared using a predmode declaration. This
    capability is now needed by add_class.m.

    Move the code creating an error message into its own function, and export
    that function for add_class.m.

compiler/polymorphism_type_info.m:
    Fix some comment rot.

compiler/base_typeclass_info.m:
compiler/call_gen.m:
compiler/dead_proc_elim.m:
compiler/deep_profiling.m:
compiler/direct_arg_in_out.m:
compiler/error_msg_inst.m:
compiler/float_regs.m:
compiler/get_dependencies.m:
compiler/higher_order.m:
compiler/hlds_error_util.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_typeclass_table.m:
compiler/instance_method_clauses.m:
compiler/intermod.m:
compiler/make_hlds_error.m:
compiler/ml_call_gen.m:
compiler/mode_errors.m:
compiler/modes.m:
compiler/module_qual.qualify_items.m:
compiler/old_type_constraints.m:
compiler/parse_class.m:
compiler/parse_tree_out.m:
compiler/parse_tree_out_inst.m:
compiler/polymorphism_post_copy.m:
compiler/polymorphism_type_class_info.m:
compiler/prog_item.m:
compiler/prog_rep.m:
compiler/recompilation.usage.m:
compiler/state_var.m:
compiler/type_class_info.m:
compiler/typecheck_debug.m:
compiler/typecheck_error_type_assign.m:
compiler/typecheck_errors.m:
compiler/typecheck_msgs.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.

tests/invalid/bug476.err_exp:
tests/invalid/tc_err1.err_exp:
tests/invalid/tc_err2.err_exp:
tests/invalid/typeclass_bogus_method.err_exp:
tests/invalid/typeclass_missing_mode.err_exp:
tests/invalid/typeclass_missing_mode_2.err_exp:
tests/invalid/typeclass_mode.err_exp:
tests/invalid/typeclass_mode_2.err_exp:
tests/invalid/typeclass_mode_3.err_exp:
tests/invalid/typeclass_mode_4.err_exp:
tests/invalid/typeclass_test_10.err_exp:
tests/invalid/typeclass_test_3.err_exp:
tests/invalid/typeclass_test_4.err_exp:
tests/invalid/typeclass_test_5.err_exp:
tests/invalid/typeclass_test_9.err_exp:
    Expect the updated wording of some error messages.
2022-11-22 02:27:33 +11:00
Zoltan Somogyi
307b1dc148 Split up error_util.m into five modules.
compiler/error_spec.m:
    This new module contains the part of the old error_util.m that defines
    the error_spec type, and some functions that can help construct pieces
    of error_specs. Most modules of the compiler that deal with errors
    will need to import only this part of the old error_util.m.

    This change also renames the format_component type to format_piece,
    which matches our long-standing naming convention for variables containing
    (lists of) values of this type.

compiler/write_error_spec.m:
    This new module contains the part of the old error_util.m that
    writes out error specs, and converts them to strings.

    This diff marks as obsolete the versions of predicates that
    write out error specs to the current output stream, without
    *explicitly* specifying the intended stream.

compiler/error_sort.m:
    This new module contains the part of the old error_util.m that
    sorts lists of error specs and error msgs.

compiler/error_type_util.m:
    This new module contains the part of the old error_util.m that
    convert types to format_pieces that generate readable output.

compiler/parse_tree.m:
compiler/notes/compiler_design.html:
    Include and document the new modules.

compiler/error_util.m:
    The code remaining in the original error_util.m consists of
    general utility predicates and functions that don't fit into
    any of the modules above.

    Delete an unneeded pair of I/O states from the argument list
    of a predicate.

compiler/file_util.m:
    Move the unable_to_open_file predicate here from error_util.m,
    since it belongs here. Mark another predicate that writes
    to the current output stream as obsolete.

compiler/hlds_error_util.m:
    Mark two predicates that wrote out error_spec to the current output
    stream as obsolete, and add versions that take an explicit output stream.

compiler/Mercury.options:
    Compile the modules that call the newly obsoleted predicates
    with --no-warn-obsolete, for the time being.

compiler/*.m:
    Conform to the changes above, mostly by updating import_module
    declarations, and renaming format_component to format_piece.
2022-10-12 20:50:16 +11:00
Zoltan Somogyi
07f877bc3f Carve term_context.m out of term.m.
library/term.m:
library/term_context.m:
    As above.

    Rename the term.context type as term_context.term_context, with
    term.context now being defined as an equivalence type.

    Replace the context_init function and predicate and the dummy_context_init
    function with just one function: dummy_context. This name includes
    the important part (the fact that it return a *dummy* context) and deletes
    the nonimportant part (dummy contexts are just about never updated,
    so the function does not really "initialize" them).

    Reduce function/predicate pairs that do the same thing to just a function.

library/MODULES_DOC:
library/library.m:
    Add the new module to the list of standard library modules.

NEWS:
    Mention the new module, and the obsoleting of the moved predicates
    and functions in term.m.

compiler/*.m:
library/*.m:
    Conform to the changes above.
2022-08-23 12:56:37 +10:00
Zoltan Somogyi
4c9d04434a Classify pred_names into four categories.
compiler/pred_name.m:
    Group pred_origins into four categories, giving each category its own
    function symbol. The categories are

    - predicates that contain, or may contain, code directly written
      by the user;
    - predicates created wholly by the compiler,
    - predicates created by the compiler by transforming a predicate, and
    - predicates created by the compiler by transforming a procedure.

    We distinguish between the first two because we want to report
    errors only in user-written code, since reporting an error that
    the user is powerless to fix is not a good idea.

    We distinguish between the last two just to allow us to store
    the proc_id of the transformed procedure next to its pred_id.

compiler/higher_order.m:
    Replace a boolean with value of a bespoke type.

    Rename some predicates to avoid ambiguity.

compiler/*.m:
    Conform to the changes above.
2022-07-23 09:28:40 +10:00
Zoltan Somogyi
1eb1e239b3 Move the pred_origin type to pred_name.m.
compiler/pred_name.m:
    Add the pred_origin type and its component types, moved here from
    hlds_pred.m and hlds_rtti.m.

    Also, add the functions and predicates that convert pred_origins to
    strings, moved here from hlds_pred.m, hlds_out_util.m and layout_out.m.

compiler/hlds_pred.m:
    Delete the pred_origin type moved to pred_name.m.

compiler/hlds_rtti.m:
    Delete the instance_method_constraints type moved to pred_name.m.
    It has nothing to do with RTTI, and was not used in hlds_rtti.m itself.
    The only data structure it is part of is pred_origin, though
    it is used as temporary data by a few other modules.

compiler/hlds_out_util.m:
compiler/hlds_pred.m:
compiler/layout_out.m:
    Delete the functions and predicates moved to pred_name.m.

compiler/*.m:
    Conform to the change above, mostly by adding imports of pred_name.m,
    in a few cases replacing hlds_pred.m or hlds_rtti.m.
2022-07-21 05:02:44 +10:00
Zoltan Somogyi
af196031ea Move pred_origin towards a structured pred_name.
compiler/hlds_pred.m:
    Add a long comment about using pred_origin as a structured pred name.

    Delete the origin_created pred_origin with origin_deforestation,
    which was one of two ways that the compiler could create new predicates
    that weren't derived from one existing predicate, procedure, or other
    single Mercury construct. (Deforestation picks a conjunction of two
    or more goals, and created a new predicate out of *them*.)
    Replace the other, created_by_io_tabling, with a pred_transformation,
    since in that case, the new predicate *is* derived from a single
    existing predicate.

    Add a mechanism for recording the predicates created by the distance
    granularity transformation, which previously was recorded in the predicate
    name, but not in the pred_origin.

    Deleted the dnf predicate transform, since it hasn't been used
    since the Aditi backend was deleted in 2006.

    Include the pred_or_func distinction, and the original user arity,
    in the pred_origin of user defined predicates and functions.

    Include in most other pred transformations the parameters that are
    now recorded in the corresponding transform_name used in pred_name.m,
    with the exception of the pred_or_func distinction, since it is now
    available by following the chain of transforms to the base pred_origin,
    which should include that info.

    Use a type_ctor, not its components, in a pred origin.

    Shorten the too-long names of some function symbols.

compiler/distance_granularity.m:
    Record the transform done by this module.

    Use state variables where appropriate.

    Use more consistent variable names.

    Eliminate excessive indentation in the example transformation
    in the module introduction comment.

compiler/loop_inv.m:
    Fix a bug. The sequence number field of the transform_name
    was being filled with something other than a sequence number,
    which could be the same for two transformations. (Or at least,
    I have seen no convincing argument for why they couldn't be.
    If such an argument existed, the sequence number field would
    not be needed, so the old code would still have been wrong,
    just for a different reason :-)

    Rename a predicate to avoid ambiguity.

compiler/hlds_module.m:
    Add the per-context counter needed by the new code in loop_inv.m.

compiler/pd_info.m:
    The predicate that defines a new predicate always specifies
    the transform_name as tn_deforestation, so don't leave it up
    to the caller to specify the pred_origin of the new predicate;
    instead, construct it here as a deforestation transform of the
    base predicate. That is the origin argument that our one caller
    always specified anyway.

compiler/purity.m:
    Use a full switch over pred_origins, not a partial one,
    to make a decision.

compiler/accumulator.m:
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_solver.m:
compiler/deforest.m:
compiler/dep_par_conj.m:
compiler/higher_order.m:
compiler/hlds_defns.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/inlining.m:
compiler/layout_out.m:
compiler/lco.m:
compiler/mode_errors.m:
compiler/par_loop_control.m:
compiler/polymorphism.m:
compiler/prog_item.m:
compiler/ssdebug.m:
compiler/table_gen.m:
compiler/trace_params.m:
compiler/tupling.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/xml_documentation.m:
    Conform to the changes above.
2022-07-20 01:05:34 +10:00
Zoltan Somogyi
f5ec674e18 Rename the hlds_class_interface type.
compiler/hlds_class.m:
    The name "hlds_class_interface" suggests that it is a HLDS version
    of the "class_interface" type defined in prog_data.m, but it is
    not that at all. While the class_interface type does contain
    the compiler's internal version of what is between the []s in an
    instance declaration, the hlds_class_interface type was defined
    to be hold a list of pred_proc_ids. They are the pred_proc_ids
    of the implementations of the methods, but they are not an interface.

    Therefore this diff renames the hlds_class_interface type
    to method_pred_proc_ids, and renames the fields of the structures
    representing typeclasses and instances accordingly.

compiler/base_typeclass_info.m:
compiler/check_typeclass.m:
compiler/dead_proc_elim.m:
compiler/direct_arg_in_out.m:
compiler/float_regs.m:
compiler/higher_order.m:
compiler/hlds_out_typeclass_table.m:
compiler/intermod.m:
compiler/old_type_constraints.m:
compiler/polymorphism_post_copy.m:
compiler/polymorphism_type_class_info.m:
compiler/type_class_info.m:
compiler/xml_documentation.m:
    Conform to the change above, updating variable names as well as
    the changed type and field names.

    In check_typeclass.m, put class_interface arguments before
    method_pred_proc_ids arguments.
2022-02-08 21:01:26 +11:00
Zoltan Somogyi
5cada10369 Rename pred_table to pred_id_table.
compiler/pred_table.m:
    As above. This addresses half of an old XXX, which is that the two types
    defined in this module, predicate_table and pred_table (as it was then)
    should have names that (a) say what they do, and (b) are distinct.
    Addressing the other half requires a more descriptive but not-too-long
    name to replace "predicate_table".

    Rename the predicates that operate on the type to follow the name change.

    Add a distinguishing prefix to the names of the fields of the
    predicate_table type.

compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_pragma.m:
compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_special_pred.m:
compiler/arg_info.m:
compiler/bytecode_gen.m:
compiler/clause_to_proc.m:
compiler/closure_gen.m:
compiler/cse_detection.m:
compiler/dead_proc_elim.m:
compiler/deep_profiling.m:
compiler/default_func_mode.m:
compiler/det_analysis.m:
compiler/det_util.m:
compiler/direct_arg_in_out.m:
compiler/distance_granularity.m:
compiler/export.m:
compiler/float_regs.m:
compiler/goal_mode.m:
compiler/granularity.m:
compiler/hlds_defns.m:
compiler/hlds_error_util.m:
compiler/hlds_module.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_module.m:
compiler/hlds_out_util.m:
compiler/hlds_pred.m:
compiler/hlds_statistics.m:
compiler/implementation_defined_literals.m:
compiler/inlining.m:
compiler/intermod.m:
compiler/introduce_exists_casts.m:
compiler/introduce_parallelism.m:
compiler/lambda.m:
compiler/lco.m:
compiler/make_hlds_passes.m:
compiler/mark_tail_calls.m:
compiler/mercury_compile_llds_back_end.m:
compiler/ml_proc_gen.m:
compiler/mode_info.m:
compiler/modecheck_call.m:
compiler/modes.m:
compiler/oisu_check.m:
compiler/old_type_constraints.m:
compiler/passes_aux.m:
compiler/polymorphism.m:
compiler/polymorphism_post_copy.m:
compiler/post_typecheck.m:
compiler/pre_typecheck.m:
compiler/proc_gen.m:
compiler/proc_requests.m:
compiler/simplify_proc.m:
compiler/stm_expand.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.m:
compiler/structure_sharing.analysis.m:
compiler/switch_detection.m:
compiler/table_gen.m:
compiler/term_constr_build.m:
compiler/term_constr_initial.m:
compiler/term_constr_util.m:
compiler/term_util.m:
compiler/termination.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/typecheck_info.m:
compiler/unused_args.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the change in pred_table.m.

    Refer to values of the renamed type using a consistent naming scheme.

    When the affected code repeats the body of existing helper predicates
    for lookup up a pred_info or proc_info, or updating a proc_info
    inside a pred_info, or updating a pred_info inside a module_info,
    call the helper predicate instead. This makes code shorter and less
    cluttered, and the use of the helper predicates for updates automatically
    ensures that we don't accidentally update a stale version of the relevant
    table. (This has sometimes been a problem in the past.)

    In a few places, carve a new predicate for processing one element
    of a list out of an existing predicate for processing all list elements.
2022-02-03 10:01:21 +11:00
Zoltan Somogyi
254cd500bf Add bespoke type for du types' details.
compiler/hlds_data.m:
    As above. The other kinds of types already had bespoke types
    for *their* details.

compiler/add_type.m:
compiler/du_type_layout.m:
    Instead of passing values of the hlds_type_body with an inst
    that said they were du types, pass values of the new types instead,
    which is significantly simpler.

compiler/add_foreign_enum.m:
compiler/add_special_pred.m:
compiler/check_typeclass.m:
compiler/code_info.m:
compiler/dead_proc_elim.m:
compiler/det_report.m:
compiler/direct_arg_in_out.m:
compiler/equiv_type_hlds.m:
compiler/foreign.m:
compiler/hlds_out_module.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen_test.m:
compiler/ml_unify_gen_util.m:
compiler/mlds.m:
compiler/mode_util.m:
compiler/post_term_analysis.m:
compiler/recompilation.usage.m:
compiler/resolve_unify_functor.m:
compiler/simplify_goal_ite.m:
compiler/special_pred.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/term_norm.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/unify_proc.m:
compiler/untupling.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.
2021-07-01 08:26:04 +10:00
Zoltan Somogyi
0d7c8a7654 Specify pred or func for all pragmas.
*/*.m:
    As above.

configure.ac:
    Require the installed compiler to support this capability.
2021-06-16 15:23:58 +10:00
Zoltan Somogyi
40725f170e Replace ten int cons_ids with one.
We currently have one function symbol in the cons_id type for each
of our ten types of integer constants: signed vs unsigned, and
word-sized, 8-bit, 16-bit, 32-bit and 64-bit. In most places in the compiler,
these are all treated the same, and it gets tedious to have to write
the same logic ten times. This diff therefore changes things so that
the distinction between int constants of these ten types is pushed
to one level lower than the cons_id type.

compiler/prog_data.m:
    Replace the ten cons_ids {int,uint}{,8,16,32,64}_const with just one,
    some_int_const, whose argument now has those function symbols.

    Add some utility functions on integer constants.

compiler/prog_out.m:
    Add a utility predicate for converting int constants to strings.

compiler/parse_tree_to_term.m:
    Add a utility predicate for converting int constants to terms.

compiler/old_type_constraints.m:
    Conform to the changes above.

    Fix an old bug, though this does not matter since this module is unused.

compiler/add_pred.m:
compiler/bytecode_gen.m:
compiler/const_prop.m:
compiler/coverage_profiling.m:
compiler/ctgc.selector.m:
compiler/dead_proc_elim.m:
compiler/deep_profiling.m:
compiler/dep_par_conj.m:
compiler/distance_granularity.m:
compiler/goal_util.m:
compiler/higher_order.m:
compiler/hlds_code_util.m:
compiler/hlds_dependency_graph.m:
compiler/hlds_out_util.m:
compiler/implementation_defined_literals.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/make_goal.m:
compiler/mercury_to_mercury.m:
compiler/ml_global_data.m:
compiler/mode_util.m:
compiler/modecheck_coerce.m:
compiler/modecheck_goal.m:
compiler/module_qual.qualify_items.m:
compiler/parse_util.m:
compiler/polymorphism.m:
compiler/polymorphism_type_info.m:
compiler/prog_ctgc.m:
compiler/prog_rep.m:
compiler/prog_type.m:
compiler/prog_util.m:
compiler/rbmm.execution_path.m:
compiler/rbmm.region_transformation.m:
compiler/simplify_goal_call.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/superhomogeneous.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above. Use the new utility predicates
    to avoid code duplication.
2021-06-03 23:58:32 +10:00
Zoltan Somogyi
93c306916a Specify streams explicitly in more modules.
compiler/module_cmds.m:
    Require all callers to specify output streams explicitly.

compiler/compile_target_code.m:
    Require callers to specify output streams explicitly in most cases.

    In the remaining cases, add "XXX STREAM" comments to request that
    the explicit streams be passed later.

    Add XXXs where preserving old behavior results in wrong-looking code.

    Modify the signature of compile_java_files to encode the invariant that
    the list of Java files given to it may not be empty.

compiler/error_util.m:
    Provide a version of an error predicate that takes explicit streams.

compiler/make.build.m:
    Mark predicates that help redirect implicit streams as predicates
    that should not be used.

compiler/make.module_target.m:
compiler/make.program_target.m:
    Add "XXX STREAM" comments to request that the explicit streams
    be passed later.

compiler/module_qual.m:
    Provide a means to construct the debug output stream.

compiler/module_qual.collect_mq_info.m:
    Use the debug output stream where relevant.

compiler/analysis.m:
compiler/export.m:
compiler/recompilation.check.m:
compiler/source_file_map.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
    Conform to the changes above, mostly by passing explicit streams.

compiler/Mercury.options:
    Stop specifying --no-warn-implicit-stream-calls for the above modules
    (those that had it specified in the first place).

    Delete a long-unneeded workaround.

compiler/mercury_compile_front_end.m:
compiler/mercury_compile_llds_back_end.m:
compiler/mercury_compile_main.m:
compiler/mercury_compile_middle_passes.m:
    Specify progress and output streams explicitly when calling the modules
    above (not in other places, just yet).
2021-05-17 22:55:06 +10:00
Peter Wang
74a31ba8ef Parse and check subtype definitions.
This is the first step towards implementing a subtypes feature.
It introduces type definitions of the form

    :- type subtype =< supertype ---> body.

Later, terms of a subtype should share a data representation with their
supertype, and it will be possible to convert terms between two types
that share "base types" using a coerce operation.

doc/reference_manual.texi:
    Add documentation for subtypes.

    Add documentation for a proposed `coerce' operation, commented out
    for now.

    Add "=<" to the list of reserved type names.

compiler/hlds_data.m:
    Add supertype field to hlds_du_type.

compiler/prog_data.m:
    Add du_supertype field to type_details_du.

    Add comment for future work.

compiler/parse_type_defn.m:
    Parse subtype definitions.

    Check that variables which occur in the "=< supertype" part
    also occur on the left hand side of the subtype definition.

compiler/parse_type_name.m:
    Add a new context for why_no_ho_inst_info.

    Add "=<" to is_known_type_name, i.e. prevent the user from defining
    a type of that name (any longer).

compiler/add_type.m:
    Rename add_du_ctors_check_foreign_type_for_cur_backend to
    add_du_ctors_check_subtype_check_foreign_type.

    In add_du_ctors_check_subtype_check_foreign_type, check that
    subtype definitions satisfy the conditions documented in the
    reference manual.

compiler/make_hlds_passes.m:
    Conform to previous renaming.

compiler/comp_unit_interface.m:
    Follow supertypes when computing the required type constructors
    whose definitions need to be kept in the implementation section
    of a .int file.

compiler/equiv_type.m:
compiler/equiv_type_hlds.m:
    Replace equivalence types in supertypes.

compiler/module_qual.qualify_items.m:
    Perform module qualification in supertypes.

compiler/hlds_out_module.m:
    Write out the "=< supertype" part of subtype definitions.

compiler/parse_tree_out.m:
    Write out the "=< supertype" part of subtype definitions.

compiler/recompilation.usage.m:
    Follow supertypes when finding used items.

compiler/add_foreign_enum.m:
compiler/add_special_pred.m:
compiler/check_parse_tree_type_defns.m:
compiler/check_typeclass.m:
compiler/code_info.m:
compiler/dead_proc_elim.m:
compiler/decide_type_repn.m:
compiler/det_report.m:
compiler/direct_arg_in_out.m:
compiler/du_type_layout.m:
compiler/foreign.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen_test.m:
compiler/ml_unify_gen_util.m:
compiler/post_term_analysis.m:
compiler/prog_type.m:
compiler/recompilation.check.m:
compiler/resolve_unify_functor.m:
compiler/simplify_goal_ite.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/term_norm.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to HLDS changes.

    Add comments for future work.

tests/invalid/Mmakefile:
tests/invalid/subtype_abstract.err_exp:
tests/invalid/subtype_abstract.m:
tests/invalid/subtype_circular.err_exp:
tests/invalid/subtype_circular.m:
tests/invalid/subtype_ctor_arg.err_exp:
tests/invalid/subtype_ctor_arg.m:
tests/invalid/subtype_eqv.err_exp:
tests/invalid/subtype_eqv.m:
tests/invalid/subtype_exist_constraints.err_exp:
tests/invalid/subtype_exist_constraints.m:
tests/invalid/subtype_exist_vars.err_exp:
tests/invalid/subtype_exist_vars.m:
tests/invalid/subtype_foreign.err_exp:
tests/invalid/subtype_foreign.m:
tests/invalid/subtype_foreign_supertype.err_exp:
tests/invalid/subtype_foreign_supertype.m:
tests/invalid/subtype_foreign_supertype2.err_exp:
tests/invalid/subtype_foreign_supertype2.err_exp2:
tests/invalid/subtype_foreign_supertype2.m:
tests/invalid/subtype_ho.err_exp:
tests/invalid/subtype_ho.m:
tests/invalid/subtype_invalid_supertype.err_exp:
tests/invalid/subtype_invalid_supertype.m:
tests/invalid/subtype_not_subset.err_exp:
tests/invalid/subtype_not_subset.m:
tests/invalid/subtype_syntax.err_exp:
tests/invalid/subtype_syntax.m:
tests/invalid_submodules/Mercury.options:
tests/invalid_submodules/Mmakefile:
tests/invalid_submodules/subtype_submodule.err_exp:
tests/invalid_submodules/subtype_submodule.m:
tests/valid/Mmakefile:
tests/valid/subtype_basic.m:
    Add test cases.
2021-03-15 11:16:31 +11:00
Zoltan Somogyi
c2f92d5454 Partition extensions into ".m" and "all others".
This is a first step towards a much finer grained partition.

compiler/file_names.m:
    Split the ext type into ext_src and ext_other, as mentioned above.

    Add the first predicate for checking whether a string falls into
    a given category of extensions.

    Add an XXX proposing a better solution for an old problem that does not
    actually arise in practice.

compiler/compile_target_code.m:
    Split the two-moded predicate maybe_pic_object_file_extension into
    two separate one-mode predicates, one for each old mode. The
    implementations of the two modes were already separate, because
    the two modes already did different jobs: while one went from PIC
    to an "extension", the other went from an "extension string" to PIC.
    Until now, "extension" and "extension string" were equivalent;
    after this diff, they aren't anymore.

    Delete an unused argument.

compiler/make.util.m:
    Split the two-moded predicate target_extension into
    two separate one-mode predicates, one for each old mode,
    for the same reason as maybe_pic_object_file_extension above:
    the fact that "extension" and "extension string" are now distinct.

compiler/options_file.m:
    Move debug infrastructure here from mercury_compile_main.m, to help
    debug possible problems with options files. (I had such a problem
    while writing this diff.)

    Improve how progress messages are printed.

compiler/options.m:
    Make an error message more useful.

compiler/mercury_compile_main.m:
    Add infrastructure for debugging possible problems with command lines.
    (I had such a problem while writing this diff.)

compiler/analysis.m:
    Conform to the changes above. Put the arguments of some methods
    into the same order as similar predicates in file_names.m.

compiler/find_module.m:
    Conform to the changes above. Delete an unused argument,

compiler/analysis.file.m:
compiler/du_type_layout.m:
compiler/elds_to_erlang.m:
compiler/export.m:
compiler/fact_table.m:
compiler/file_kind.m:
compiler/generate_dep_d_files.m:
compiler/grab_modules.m:
compiler/llds_out_file.m:
compiler/make.build.m:
compiler/make.deps_set.m:
compiler/make.m:
compiler/make.module_dep_file.m:
compiler/make.module_target.m:
compiler/make.program_target.m:
compiler/mercury_compile_front_end.m:
compiler/mercury_compile_llds_back_end.m:
compiler/mercury_compile_middle_passes.m:
compiler/mercury_compile_mlds_back_end.m:
compiler/mlds_to_c_file.m:
compiler/mlds_to_cs_file.m:
compiler/mlds_to_java_file.m:
compiler/mmc_analysis.m:
compiler/mode_constraints.m:
compiler/module_cmds.m:
compiler/prog_foreign.m:
compiler/read_modules.m:
compiler/recompilation.check.m:
compiler/recompilation.usage.m:
compiler/source_file_map.m:
compiler/write_deps_file.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
2020-08-17 23:43:15 +10:00
Zoltan Somogyi
52c0919975 Make filename extensions a separate type, ...
... to allow later changes to its definition.

compiler/file_names.m:
    We used to represent filename extensions simply as strings. This meant
    all calls to the predicates in file_names.m that convert module names
    to file names with various suffixes had to go through a complicated
    sequence of tests that effectively partition the extensions into
    several classes, with all extensions in a class being treated the same
    but different classes being treated differently. And since this general
    translation process is quite convoluted (which is not helped by it
    being spread across several predicates), it is very hard to construct
    a correctness argument for it.

    It would be better to represent the different classes of extensions
    explicitly, in a du type, with each function symbol of that type
    representing all the extensions in the corresponding class (in the sense
    of the paragraph above). However, getting there in one diff would make
    that diff far too hard to test and to review. So this first diff
    starts by simply making extension a notag type.

    The above is the first step in implementing one old XXX. This diff
    fully implements another old XXX, which is to make the argument order
    of several predicates friendly to higher order code.

    Add infrastructure for profiling how often this code makes directories.

    Delete an unused type.

    Add comments outlining proposed future improvements.

compiler/analysis.file.m:
compiler/analysis.m:
compiler/compile_target_code.m:
compiler/du_type_layout.m:
compiler/elds_to_erlang.m:
compiler/export.m:
compiler/fact_table.m:
compiler/file_kind.m:
compiler/find_module.m:
compiler/generate_dep_d_files.m:
compiler/grab_modules.m:
compiler/llds_out_file.m:
compiler/make.build.m:
compiler/make.m:
compiler/make.module_dep_file.m:
compiler/make.module_target.m:
compiler/make.program_target.m:
compiler/make.util.m:
compiler/mercury_compile_front_end.m:
compiler/mercury_compile_llds_back_end.m:
compiler/mercury_compile_main.m:
compiler/mercury_compile_middle_passes.m:
compiler/mercury_compile_mlds_back_end.m:
compiler/mlds_to_c_file.m:
compiler/mlds_to_cs_file.m:
compiler/mlds_to_java_file.m:
compiler/mmc_analysis.m:
compiler/mode_constraints.m:
compiler/module_cmds.m:
compiler/module_imports.m:
compiler/parse_tree_out.m:
compiler/prog_foreign.m:
compiler/read_modules.m:
compiler/recompilation.check.m:
compiler/recompilation.usage.m:
compiler/write_deps_file.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
    Conform to the change to file_names.m.

    Consistently use "Ext" for the abstract representation of extensions
    and "ExtStr" for their string representation.

    In a few places, add "XXX EXT" where the code manipulates extensions
    as strings in a way that potentially inferferes with the partition
    of extensions into classes.

    In a few places, rename predicates to avoid ambiguities. factor out
    common code, delete unneeded arguments, replace bools with bespoke types,
    and make similar minor improvements.

    In a few places, remove rafe-isms, such as the use ^elem.
2020-08-14 20:30:36 +10:00
Zoltan Somogyi
5c52cf0cde Standardize on "sym_name_arity" ...
... replacing "sym_name_AND_arity".
2020-03-15 19:37:18 +11:00
Zoltan Somogyi
5e075745dd Add a divider for clarity. 2020-03-10 02:03:12 +11:00
Zoltan Somogyi
36c2000516 Add the one_or_more and one_or_more_map modules to the library.
library/one_or_more.m:
    We used to have a type named one_or_more in the list module representing
    nonempty lists. It had literally just two predicates and two functions
    defined on it, three of which did conversions to and from lists, which
    limited their usefulness.

    This new module is the new home of the one_or_more type, together with
    a vastly expanded set of utility predicates and functions. Specifically,
    it implements every operation in list.m which makes sense for nonempty
    lists.

library/list.m:
    Delete the code moved over to one_or_more.m.

library/one_or_more_map.m:
    This new module is a near copy of multi_map.m, with the difference being
    that while the multi_map type defined in multi_map.m maps each key
    to a list(V) of values (a list that happens to always be nonempty),
    the one_or_more_map type defined in one_or_more_map.m maps each key
    to a one_or_more(V) of values (which enforces the presence of at least
    one value for each key in the type).

library/map.m:
    Mention the existence of one_or_more_map.m as well as multi_map.m.

library/MODULES_DOC:
library/library.m:
    List the new modules as belonging to the standard library.

NEWS:
    Mention the new modules, and the non-backwards-compatible changes to
    list.m.

compiler/*.m:
    Import the one_or_more module when needed.

tests/hard_coded/test_one_or_more_chunk.{m,exp}:
    Test the one predicate in one_or_more.m that is non-trivially different
    from the corresponding predicate in list.m: the chunk predicate.

tests/hard_coded/Mmakefile:
    Enable the new test case.
2020-02-28 14:29:05 +11:00
Peter Wang
ed78596ed7 Use source file map to exclude default source file names.
If a file name is listed in the source file map then
do not use that file name as the source file for any other module.
Fixes Mantis bug #489.

compiler/source_file_map.m:
    Make the source_file_map a bimap.

    Make lookup_module_source_file return `no' if there is no source
    file for the requested module, because the default file name for
    that module has been mapped to another module.

compiler/file_names.m:
    Make module_name_to_file_name_general return a dummy file name
    (that is not supposed to exist) when lookup_module_source_file
    returns `no'.

compiler/globals.m:
compiler/introduce_parallelism.m:
compiler/xml_documentation.m:
    Conform to changes.
2020-01-14 13:01:41 +11:00
Zoltan Somogyi
e9430b115a Prep for recording simple type representations in .int3 files.
compiler/decide_type_repn.m:
    New module for computing the set of type representation items
    to put into the interface files of a module. For now, it generates
    this information only for .int3 files.

compiler/parse_tree.m:
compiler/notes/compiler_design.html:
    Add the new module to the parse_tree package.

compiler/comp_unit_interface.m:
    Invoke the new module to add type representation items to .int3 files
    if the experiment option has the right value. Give it the information
    it needs to do its job.

compiler/add_foreign_enum.m:
    Export a predicate for use by decide_type_repn.m. Maybe eventually
    it should be *moved* to decide_type_repn.m.

compiler/hlds_data.m:
compiler/prog_data.m:
    Change the representation of lists of constructors in a type
    from lists, which can be empty, with one_or_more, which cannot.
    This encodes the invariant that a type constructor cannot have
    zero data constructors in the structure of the type.

compiler/prog_item.m:
    Change the representation of lists of constructors in a type
    from lists, which can be empty, with one_or_more, which cannot.
    This encodes the invariant that a type constructor cannot have
    zero data constructors in the structure of the type.

    Include information about assertions in type representation items
    about foreign types.

    Do not record whether a type whose representation item says its values
    are guaranteed to be word aligned is a Mercury type or a foreign type.
    We generate such items only for Mercury types; for foreign types,
    their assertions will contain that information. We need this separation
    because when we generate .int3 files, we don't the backend that we will
    eventually generate code for, and thus do not know whether a given
    foreign type declaration is in effect on that backend or not.

compiler/parse_tree_out.m:
    Fix the printing of type representation items.

compiler/prog_type.m:
    Conform to the changes above, and delete an unused predicate.

compiler/parse_type_repn.m:
    Factor out some common code.

    Fix an old bug about yes/no vs du_repn/no_du_repn.

    Conform to the changes above.

compiler/parse_pragma.m:
    Export a predicate for parse_type_repn.m.

    Note a possible improvement.

    Conform to the changes above.

compiler/add_special_pred.m:
compiler/add_type.m:
compiler/check_typeclass.m:
compiler/det_report.m:
compiler/du_type_layout.m:
compiler/equiv_type.m:
compiler/hlds_out_module.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/mode_util.m:
compiler/module_qual.qualify_items.m:
compiler/parse_tree_out_pragma.m:
compiler/parse_type_defn.m:
compiler/recompilation.check.m:
compiler/recompilation.usage.m:
compiler/resolve_unify_functor.m:
compiler/special_pred.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/term_norm.m:
compiler/type_util.m:
compiler/untupling.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.

compiler/simplify_goal_ite.m:
    Add a comment.

compiler/canonicalize_interface.m:
compiler/get_dependencies.m:
    Do not abort when seeing type representation items.

compiler/mmakefiles.m:
    Delete a predicate that this diff adds to list.m.

library/list.m:
    Add new predicates to convert from one_or_more to list
    and vice versa.

NEWS:
    Announce the new predicates.

library/bimap.m:
library/map.m:
library/tree234.m:
    Expand a comment.
2019-05-27 11:45:10 +02:00
Zoltan Somogyi
1c13290492 Store its ordinal number with each functor.
This will be needed by an upcoming change.

compiler/prog_data.m:
compiler/hlds_data.m:
    Add the new field to (respectively) the parse tree and the HLDS
    representations of constructors.

compiler/parse_type_defn.m:
    Fill in the new field when parsing function symbols in type definitions.

compiler/du_type_layout.m:
    Transmit the ordinal number from the parse tree representation of
    constructors to their HLDS representation.

    Add some predicates needed by that upcoming change.

compiler/add_special_pred.m:
compiler/add_type.m:
compiler/check_typeclass.m:
compiler/equiv_type.m:
compiler/equiv_type_hlds.m:
compiler/export.m:
compiler/hhf.m:
compiler/hlds_out_module.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/ml_type_gen.m:
compiler/mode_util.m:
compiler/module_qual.qualify_items.m:
compiler/parse_tree_out.m:
compiler/prog_type.m:
compiler/recompilation.check.m:
compiler/recompilation.usage.m:
compiler/resolve_unify_functor.m:
compiler/special_pred.m:
compiler/term_constr_build.m:
compiler/term_norm.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
    Conform to the changes above.
2018-06-08 02:58:00 +02:00
Zoltan Somogyi
24b98fdafe Pack sub-word-sized ints and dummies in terms.
Previously, the only situation in which we could pack two or more arguments
of a term into a single word was when all those arguments are enums. This diff
changes that, so that the arguments can also be sub-word-sized integers
(signed or unsigned), or values of dummy types (which occupy zero bits).

This diff also records, for each argument of a function symbol, not just
whether, and if yes, how it is packed into a word, but also at *what offset*
that word is in the term's heap cell. It is more economical to compute this
once, when the representation of the type is being decided, than to compute
it over and over again when terms with that function symbol are being
constructed or deconstructed. However, for a transition period, we compute
these offsets at *both* times, to check the consistency of the new algorithm
for computing offsets that is run at "decide representation time" with
the old algorithms run at "generate code for a unification time".

compiler/du_type_layout.m:
    Make the changes described above: pack sub-word-sized integers and
    dummy values into argument words, if possible, and if the relevant
    new option allows it. These options are temporary. If we find no problems
    with the new packing algorithm in a few weeks, we should be able to
    delete them.

    Allow 64 bit ints and uints to be stored in unboxed in two words
    on 32 bit platforms, if the relevant new option allows it. Support
    for this is not yet complete, but it makes sense to implement the
    RTTI changes for both this change and one described in the above
    paragraph together.

    For each packed argument, record not just its width, its shift and
    the mask, but also the number of bits the argument takes. Previously,
    we computed this on demand from the mask, but there is no real need
    for that when simply storing this info is so cheap.

    For all arguments, packed or not, record its offset, relative to both
    the start of the arguments, and the start of the memory cell. (The two
    are different if the arguments are preceded by either a remote secondary
    tag, the typeinfos and/or typeclass_infos describing some existentially
    typed arguments, or both.) The reason for this is given at the top.

    Centralize the decision of the parameters of packing in one predicate.

    If the option --inform-suboptimal-packing is given, print an informational
    message whenever the code deciding type representations finds that
    reordering the arguments of a function symbol would allow it to pack
    the arguments of that function symbol into less space.

compiler/options.m:
    Add the option --allow-packing-ints which controls whether
    du_type_layout.m will attempt to pack {int,uint}{8,16,32} arguments
    alongside enum arguments.

    Add the option --allow-packing-dummies which controls whether
    du_type_layout.m will optimize away (in other words, represent in 0 bits)
    arguments of dummy types.

    Add the option --allow-double-word-ints which controls whether
    du_type_layout.m will store arguments of the types int64 and uint64
    unboxed in two words on 32 bit platforms, the way it currently stores
    double precision floats.

    All three those options are off by default, which preserves binary
    compatibility with existing code. However, the first two are ready
    to be switched on (the third is not).

    All three options are intended to be present in the compiler
    only until these changes are tested. Once we deem them sufficiently
    tested, I will modify the compiler to always do the packing they control,
    at which point we can delete these options. This is why they are not
    documented.

    Add the option --inform-suboptimal-packing, whose meaning is described
    above.

doc/user_guide.texi:
    Document --inform-suboptimal-packing.

compiler/prog_data.m:
    For each argument of a function symbol in a type definition, use
    a new type called arg_pos_width to record the extra information
    mentioned above in (offsets for all arguments, and number of bits
    for packed arguments).

    For each function symbol that has some existential type constraints,
    record the extra information mentioned for parse_type_defn.m below.

compiler/hlds_data.m:
    Include the position, as well as the width, in the representation
    of the arguments of function symbols.

    Previously, we used the integer 0 as a tag for dummies. Add a tag to
    represent dummy values, since this gives more information to any code
    that sees that tag.

compiler/ml_unify_gen.m:
compiler/unify_gen.m:
    Handle the packing of dummy values, and of sub-word-sized ints and uints.

    Compare the cell offset of each argument computed using existing
    algorithms here with the cell offset recorded in the argument's
    representation, and abort if they are different.

    In some cases, restructure code a bit to make it possible.
    For example, for tuples and closures, this means that instead of
    simply recording that each tuple argument or closure element
    is a full word, we must record its correct offset as well.

    Handle the new dummy_tag.

    Add prelim (not yet finished) support for double-word int64s/uint64s
    on 32 bit platforms.

    When packing the values of two or more variables (or constants) into a
    single word in a memory cell, optimize away operations that are no-ops,
    such as shifting anything by zero bits, shifting the constant zero
    by any number of bits, and ORing anything with zero. This makes the
    generated code easier to read. It is probably also faster for us
    to do it here than to write out a bigger expression, have the C compiler
    read in the bigger expression, and then later make the same optimization.

    In ml_unify_gen.m, avoid the unnecessary use of a list of the argument
    variables' types separate from the list of the argument variables
    themselves; just look up the type of each argument variable when it is
    processed.

compiler/add_special_pred.m:
    When creating special (unify and compare) predicates for tuples,
    include the offsets in the representation of their arguments.

    Delete an unused predicate.

compiler/llds.m:
    Add a new way to create an rval: a cast. We use it to implement
    the extraction of signed sub-word-sized integers from packed argument
    words in terms. Masking the right N bits out of the packed word
    leaves the other 32-N or 64-N bits as zeroes; a cast to int8_t,
    int16_t or int32_t will copy the sign bit to these bits.
    Likewise, when we pack signed int{8,16,32} values into words,
    we cast them to their unsigned versions to throw away any sign-extension
    bits in their original word-sized representations.

    No similar change is needed for the MLDS, since that already had
    a mechanism for casts.

compiler/mlds.m:
    Note a potential simplification in the MLDS.

compiler/builtin_lib_types.m:
    Add functions to return the Mercury representation of the int64
    and uint64 types.

compiler/foreign.m:
    Export a specialized version of an existing predicate, to allow
    ml_unify_gen.m to avoid the costs of the more general version.

compiler/hlds_out_module.m:
    Always print the representations of all arguments, since the
    inclusion of position information in those representation means that
    the representations of even all-full-word-argument terms are of potential
    interest when debugging term representations.

compiler/lco.m:
    Do not try to apply LCO to arguments of dummy types. (We could optimize
    them differently, by filling them in before they are "computed", but
    that is a separate optimization, which is of *very* low priority.)

compiler/liveness.m:
    Do not include variables of dummy types in resume points.

    The reason for this is that the code that establishes a resume point
    returns, for each such variable, a list of *lvals* where that variable
    can be found. The new code in unify_gen.m will optimize away assignments
    to values of dummy types, so there is *no* lval where they can be found.
    We could allocate one, but doing so would be a pessimization. Instead,
    we simply don't save and restore such values. When their value (which is
    always 0) is needed, we can create them out of thin air.

compiler/ml_global_data.m:
    Include the target language in the ml_global_data structure, to prevent
    some of its users having to look it up in the module_info.

    Add notes about the specializing the implementation of arrays of
    int64s/uint64s on 32 bit platforms.

compiler/check_typeclass.m:
compiler/ml_type_gen.m:
    Add sanity checks of the new precomputed fields of exist_constraints.

    Conform to the changes above.

compiler/mlds_to_c.m:
    Add prelim (not yet finished) support for double-word int64s/uint64s
    on 32 bit platforms.

    Add notes about possible optimizations.

compiler/parse_type_defn.m:
    When a function symbol in a type definition contains existential
    arguments, precompute and store the set of constrained and unconstrained
    type variables. The code in du_type_layout.m needs this information
    to compute the number of slots occupied by typeinfos and typeclass_infos
    in memory cells for this function symbol, and several other places
    in the compiler do too. It is easier and faster to compute this
    information just once, and this is the earliest time what that can be done.

compiler/type_ctor_info.m:
    Use the prerecorded information about existential types to simplify
    the code here

compiler/polymorphism.m:
    Add an XXX about possibly using the extra info we now record in
    exist_constraints to simplify the job of polymorphism.m.

compiler/pragma_c_gen.m:
compiler/var_locn.m:
    Create the values of dummy variables from scratch, if needed.

compiler/rtti.m:
    Replace a bool with a bespoke type.

compiler/rtti_out.m:
compiler/rtti_to_mlds.m:
    When generating RTTI information for the LLDS and MLDS backends
    respectively, record new kinds of arguments as needing special
    treatment. These are int64s and uint64s stored unboxed in two words
    on 32 bit platforms, {int,uint}{8,16,32} values packed into words,
    and dummy arguments. Each of these has a special code: its own negative
    negative value in the num_bits field of the argument.

    Generate slightly better formatted output.

compiler/type_util.m:
    Delete a predicate that isn't needed anymore.

compiler/opt_util.m:
    Delete a function that hasn't been needed for a while.

    Conform to the changes above.

compiler/arg_pack.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/code_util.m:
compiler/ctgc.selector.m:
compiler/dupelim.m:
compiler/dupproc.m:
compiler/equiv_type.m:
compiler/equiv_type_hlds.m:
compiler/erl_code_gen.m:
compiler/erl_rtti.m:
compiler/export.m:
compiler/exprn_aux.m:
compiler/global_data.m:
compiler/jumpopt.m:
compiler/livemap.m:
compiler/llds_out_data.m:
compiler/middle_rec.m:
compiler/ml_closure_gen.m:
compiler/ml_switch_gen.m:
compiler/ml_top_gen.m:
compiler/module_qual.qualify_items.m:
compiler/opt_debug.m:
compiler/parse_tree_out.m:
compiler/peephole.m:
compiler/recompilation.usage.m:
compiler/resolve_unify_functor.m:
compiler/stack_layout.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/switch_util.m:
compiler/typecheck.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.

compiler/llds_out_util.m:
    Add a comment.

compiler/ml_code_util.m:
    Factor out some common code.

runtime/mercury_type_info.h:
    Allocate special values of the MR_arg_bits field of the MR_DuArgLocn type
    to designate arguments as two word int64/uint64s, as sub-word-sized
    arguments of types {int,uint}{8,16,32}, or as arguments of dummy types.
    (We already had a special value for two word float arguments.)

    Document the list of places that know about this code, so that they
    can be updated if and when it changes.

library/construct.m:
    Handle the construction of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

    Factor out the code common to the sectag-present and sectag-absent cases,
    to make it possible to do the above in just *one* place.

library/store.m:
    Add an XXX to a place that I don't think handles two word arguments
    correctly. (I think this is an old bug.)

runtime/mercury_deconstruct.c:
    Handle the deconstruction of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

runtime/mercury_deep_copy_body.h:
    Handle the copying of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

    Give a macro a more descriptive name.

runtime/mercury_type_info.c:
    Handle taking the size of terms with two-word int64/uint64 arguments,
    with packed {int,uint}{8,16,32} arguments, and with dummy arguments.

runtime/mercury.h:
    Put related definitions next to each other.

runtime/mercury_deconstruct.h:
runtime/mercury_ml_expand_body.h:
    Fix indentation.

tests/hard_coded/construct_test.{m,exp}:
    Add to this test case a test of the construction, via the library's
    construct.m module, of terms containing packed sub-word-sized integers,
    and packed dummies.

tests/hard_coded/deconstruct_arg.{m,exp}:
    Convert the source code of this test case to state variable notation,
    and update the line number references (in the names of predicates created
    from lambda expressions) accordingly.

tests/hard_coded/uint64_ground_term.{m,exp}:
    A new test case to check that uint64 values too large to be int64 values
    can be stored in static structures.

tests/hard_coded/Mmakefile:
    Enable the new test case.
2018-05-05 13:22:19 +02:00
Zoltan Somogyi
15aa457e12 Delete $module arg from calls to unexpected. 2018-04-07 18:25:43 +10:00
Zoltan Somogyi
1693c784fe Carve hlds_class.m out of hlds_data.m.
compiler/hlds_class.m:
    New module containing the parts of hlds_data.m that deal with
    type classes and type class constraints.

compiler/hlds_data.m:
    Delete the moved code.

compiler/hlds.m:
    Include the new module.

compiler/notes/compiler_design.html:
    Document the new module.

compiler/add_class.m:
compiler/base_typeclass_info.m:
compiler/check_typeclass.m:
compiler/dead_proc_elim.m:
compiler/float_regs.m:
compiler/higher_order.m:
compiler/hlds_code_util.m:
compiler/hlds_defns.m:
compiler/hlds_module.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/hlds_pred.m:
compiler/intermod.m:
compiler/polymorphism.m:
compiler/post_typecheck.m:
compiler/recompilation.usage.m:
compiler/resolve_unify_functor.m:
compiler/type_assign.m:
compiler/type_class_info.m:
compiler/type_constraints.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/typecheck_info.m:
compiler/typeclasses.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.
2018-02-06 02:00:08 +11:00
Zoltan Somogyi
fb97df69ed Make "compute type representations" a separate pass.
The ultimate purpose of this diff is to prepare for future improvements
in type representations, allowing values of some data types to be represented
more compactly than up to now.

The main way this diff does that is by creating a separate pass for deciding
how values of each type should be represented. We have traditionally decided
data representations for each type as its type definition was processed
during the make_hlds pass, but these decisions were always tentative,
and could be overridden later, e.g. when we processed foreign_type or
foreign_enum pragmas for the type. This dispersed decision making algorithm
is hard to understand, and therefore to change.

This diff centralizes decisions about type representations in a separate
pass that does nothing else. It leaves the algorithm distributed among
several files (du_type_layout.m, make_tags.m, and add_foreign_enum.m) for now,
to make reviewing this diff easier, but soon after it is committed I intend
to move all the relevant code to du_type_layout.m, to centralize the decision
code in "space" as well as in time.

For the reason why this pass runs before any of the semantic analysis
passes, instead of after all of them as I originally intended and as we
discussed on m-dev in late october 2017, see the big comment at the start of
du_type_layout.m.

As per another part of that same discussion on m-dev, this diff
makes a start on implementing a new type of item, the type_repn item,
which is intended *only* to be used in compiler-generated interface files,
*not* in source files. It is only a start because we can use these items
only *after* the creation of a separate type representation decision pass,
and this diff is already very big. The code for making the compiler understand
these items will be added later. The code for generating them will be added
later still, once the code for understanding them has been installed on
all our systems.

Since I was going to be working on the affected code anyway, this diff
also carries out two other decisions that came out of that discussion:

- the deletion of the ability to reserve a tag in a type for HAL,
  either via a compiler option or via a pragma, and

- the deletion of the ability to represent a functor using the address
  of a statically allocated object (which we haven't used and won't use,
  because it slows down accesses to *all the other functors* of the type).

compiler/mercury_compile_front_end.m:
    Invoke the new pass for making decisions about type representations
    after the make_hlds pass. (We used to do only the final part of it then.)

    Fix a bad dump stage name.

    Add an extra check for what it means for a module to be error free.

    Make a sub-switch explicit.

compiler/hlds.m:
compiler/make_hlds.m:
    Move the modules that implement the new pass from the make_hlds package
    to the hlds package, to give the compiler's top level access to them.

    Make the same move for the modules that the new pass's modules need.
    Since they are now part of hlds, they cannot reach into make_hlds,
    and I think this is a cleaner solution than forwarding predicates.

    Delete some forwarding predicates that are no longer needed.

compiler/notes/compiler_design.html:
    Document the updated location of the moved modules.

    Add an XXX to note a place where the documentation has not been
    updated in the past.

compiler/du_type_layout.m:
    Add code to implement the new pass.

    Keep the algorithm for deciding type representations as close
    to the previously used algorithm as possible, since this diff
    is already big enough. (The previous algorithm was scattered across
    add_type.m, add_foreign_enum.m, and make_hlds_passes.m.)

    Simplifications and optimizations will come later, after this module
    is merged with make_tags.m and with (at least) the foreign_enum half of
    add_foreign_enum.m.

compiler/make_tags.m:
    Keep the functionality of this module, which does both the first part
    of deciding type representations (tentatively assigning tags to functors,
    an assignment that may be overridden later), and the last part (packing
    multiple adjacent less-than-word-sized enum args into a single word,
    if possible.), but simplify it where possible, and note possibilities
    for further improvements.

compiler/add_foreign_enum.m:
    This module has two halves, one dealing with foreign_enum pragmas
    and one dealing with foreign_export_enum pragmas.

    Change the half that deals with foreign_enum pragmas to just build
    a data structure that du_type_layout.m will need to make its decisions,
    this structure being a map from type_ctors to the foreign enum
    specification applicable to the current target language. Include
    in this structure a component that add_foreign_enum.m itself can use
    to report better error messages for duplicate foreign_enum pragmas;
    this component records, for each type_ctor and language, the context
    of the previous foreign_enum pragma for that combo.

    Change the input for the half that deals with foreign_export_enum pragmas
    to reflect the fact that it is invoked by du_type_layout.m after all
    decisions about type representations have already been made.

compiler/add_special_pred.m:
    Move this module from the make_hlds package to the hlds package,
    since the code that adds special preds for type is now called from
    du_type_layout.m.

    Change the names of predicates to make clear whether they add
    only the declaration of a predicate, only its definition, or both.

    Don't try to pre-guess whether the implementation of a type's
    compare predicate will need an index predicate. Let the code
    that generates calls to the index predicate both declare and define
    the index predicate. This change removes the potential for
    inconsistencies between the two pieces of code.

compiler/add_pred.m:
    Move this module from the make_hlds package to the hlds package,
    since add_special_pred.m needs access to it.

compiler/add_type.m:
    When adding a type definition to the HLDS, don't try to decide
    its representation. Any such decision was tentative anyway, due
    to the possibility of e.g. the later processing of foreign_type
    or foreign_enum pragmas for the type. Likewise, don't try to
    create the special (unify, compare) predicates for the type.
    Leave both tasks to the du_type_layout pass.

    Likewise, don't try to pack the representation of types, or record
    no_tag types in the table of no_tag types, during the post-processing
    pass either; leave both of these to du_type_layout as well.
    Rename the predicate that post_processes type definitions to reflect
    the two tasks left for it to do.

compiler/prog_data.m:
    Do not store width information about the arguments of those data
    constructors in the parse tree. That information is not computed
    until later; until then, it was always filled in with dummy values.
    (But see hlds_data.m below.)

    Use bespoke types to represent the presence or absence of user-specified
    unify and compare predicates.

    Change the representation of data constructors to use a single "maybe"
    type, not two lists, to denote the presence or absence of existentially
    typed arguments.

    Give the HLDS the ability to hold representation information about
    abstract types that in the future we will get from type_repn items
    in the defining modules' interface files.

    Delete the uses_reserved_tag type, since we never use reserved tags
    anymore.

compiler/prog_item.m:
    Add the new type_repn item type, which is not used yet.

    Delete the reserve_tag pragma.

    Fix an earlier mistake in the wording of a context message.

compiler/hlds_data.m:
    Put all the fields of hlds_du_type (the type definition variant dealing
    with discriminated union types) that deal with type representation
    issues in a single "maybe" field that is set to "no" before the
    type representation decision pass has been run.

    Add new type, constructor_repn, that stores the same information as the old
    constructor type (defined in prog_data.m), PLUS the information
    describing how terms with that data constructor are stored.

    Likewise, add a new type ctor_arg_rep, which likewise stores
    the widths of each constructor argument. When we implement
    argument reordering, we would store the offset of the arg as well.

    Since the parse tree representations of constructors and their arguments
    don't store representation information anymore, the cons_table they
    are stored in doesn't either. Make the lookup of representation information
    for a given constructor possible by adding a map to the new "maybe" field
    of hlds_du_type.

    Provide some utility predicates.

    Optimize some existing predicates.

    Rename some types to better reflect their meaning.

compiler/hlds_module.m:
    Provide a slot in the module_info for storing the information
    gathered by make_hlds.m that is needed by the new pass.

compiler/make_hlds_separate_items.m:
    When we see either a foreign_enum or a foreign_export_enum pragma,
    return values of a bespoke type for them (a type defined in
    hlds_module.m), instead of an item_pragma. This makes handling them
    considerably easier.

compiler/make_hlds_passes.m:
    With the changes in this diff, adding a type to the HLDS won't
    decide its representation. Therefore delete the code that used
    to loop over foreign_export_enum pragmas; in the absence of
    the final type representation information, it won't work right.

    Record the information that the du_type_layout pass will need
    in the module_info.

compiler/add_pragma.m:
    Delete the code for passing on foreign_enum and foreign_export_enum
    pragmas to add_foreign_enum.m; they are now passed to add_foreign_enum.m
    by du_type_layout.m.

    Move a utility predicate to make_hlds_error.m, to allow add_foreign_enum.m
    to call it.

compiler/make_hlds_error.m:
    Add the utility predicate moved from add_pragma.m.

    Move the module from the make_hlds to the hlds package.

compiler/module_qual.m:
    Provide a mechanism for recording error messages about e.g. undefined
    types without recording that we found an undefined type. This sounds
    strange, but there is a valid use case.

    When a type definition declares a functor's argument to be of an
    undefined type, that error is usually fatal; we stop the compiler
    from proceeding even to typechecking, since the typechecker will
    probably abort with a map lookup failure. Most other references
    to undefined types are similarly fatal for the same reason. However,
    if e.g. a foreign_export_enum pragma refers to an undefined type,
    that error *won't* be visible to the typechecker, and therefore
    won't crash it. The error will still cause the compiler to exit
    without generating any target language code, but at least it will be
    able to run the typechecker and other semantic analysis passes.

    Without this change, the compiler will report only one error in
    the ee_invalid.m test case; with it, it reports *every* error
    in the test case expected output.

compiler/module_qual.qualify_items.m:
    Use the capability describe above for undefined types in
    foreign_export_enum pragmas.

compiler/module_qual.qual_errors.m:
    Delete a (somewhat incorrect) copy of a predicate in prog_item.m,
    to reduce code duplication.

compiler/prog_type.m:
    Add ways to represent abstract types whose representations are nevertheless
    known (from type_repn items in the defining modules' interface files)
    to be notag or dummy types. This will be needed to fix Mantis bug #441,
    a fix that will probably be one of the first later changes to build
    on this diff.

    Delete a type moved to type_util.m.

compiler/type_util.m:
    Provide extra versions of some predicates, with the difference between
    the old and the new versions being that one requires type representations
    to have been decided already, and the other one does not.

    Move the definition of the ctor_defn type here from prog_type.m,
    since prog_type.m itself does not use it, but type_util.m does.

    Give some predicates more meaningful names.

compiler/parse_type_defn.m:
    Simplify the code for parsing type definitions, to make it easier
    to reuse to parse type_repn items.

    Add a sanity check that requires existential constraints to have
    *some* existential variables to apply to.

    Allow "type_is_representable_in_n_bits" as a synonym for
    "type_is_abstract_enum", since in the future we want to be able to pack
    e.g. multiple int8s, not just multiple enums, into a single word.

    Generate more specific error messages for some classes of malformed input.

compiler/parse_type_repn.m:
    New module to parse type_repn items.

compiler/polymorphism.m:
    Make some predicates that operate on type constructors take
    the type constructors themselves as input arguments, not a whole type
    *using* that type constructor. Put the arguments of those predicates
    in a more standard order.

    Note that some predicates don't belong in this module.

compiler/special_pred.m:
    Make the code that decides whether a special predicate for a type
    constructor can be defined lazily avoid using type representation
    information. (Actually, we now make decisions about lazy vs eager
    definitions after type representation is available, but that was
    not so in an earlier version of this change, and the new code
    is more robust.)

compiler/unify_proc.m:
    When we decide to generate code for a compare predicate that needs
    the type to have an index predicate, don't presume that the index
    predicate has already been declared and defined; instead, declare
    and define it then and there. (Index predicates are *never* called
    from anywhere else.)

    Pack the information needed to define a special predicate
    into a single structure, to simplify the above.

    Since the creation of a clause for a compare predicate may now require
    the declaration and definition of an index predicate, the module_info
    field of the unify_proc_info is now a writeable field.

    Give some predicates and function symbols more meaningful names.

    Note some problems with the existing code.

compiler/add_class.m:
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_mode.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_solver.m:
compiler/check_typeclass.m:
compiler/code_info.m:
compiler/comp_unit_interface.m:
compiler/ctgc.selector.m:
compiler/ctgc.util.m:
compiler/default_func_mode.m:
compiler/det_report.m:
compiler/equiv_type.m:
compiler/equiv_type_hlds.m:
compiler/erl_code_gen.m:
compiler/export.m:
compiler/foreign.m:
compiler/get_dependencies.m:
compiler/goal_expr_to_goal.m:
compiler/hhf.m:
compiler/higher_order.m:
compiler/hlds_code_util.m:
compiler/hlds_out_module.m:
compiler/inst_check.m:
compiler/inst_test.m:
compiler/inst_util.m:
compiler/intermod.m:
compiler/item_util.m:
compiler/make_hlds_warn.m:
compiler/ml_accurate_gc.m:
compiler/ml_simplify_switch.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen.m:
compiler/mlds_to_cs.m:
compiler/mlds_to_java.m:
compiler/mode_util.m:
compiler/modecheck_goal.m:
compiler/module_qual.collect_mq_info.m:
compiler/modules.m:
compiler/parse_item.m:
compiler/parse_pragma.m:
compiler/parse_tree.m:
compiler/parse_tree_out.m:
compiler/parse_tree_out_pragma.m:
compiler/post_term_analysis.m:
compiler/proc_requests.m:
compiler/prog_item_stats.m:
compiler/qual_info.m:
compiler/recompilation.check.m:
compiler/recompilation.usage.m:
compiler/recompilation.version.m:
compiler/resolve_unify_functor.m:
compiler/rtti.m:
compiler/rtti_out.m:
compiler/rtti_to_mlds.m:
compiler/simplify_goal_ite.m:
compiler/stack_opt.m:
compiler/state_var.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/superhomogeneous.m:
compiler/switch_gen.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/term_constr_build.m:
compiler/term_norm.m:
compiler/trailing_analysis.m:
compiler/type_constraints.m:
compiler/type_ctor_info.m:
compiler/typecheck.m:
compiler/unify_gen.m:
compiler/untupling.m:
compiler/unused_imports.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
    Conform to the changes above.

tests/invalid/Mmakefile:
    Disable the reserve_tag test case, as it is not applicable anymore.

tests/invalid/exported_foreign_enum.{m,err_exp}:
tests/invalid/pragma_qual_error.{m,err_exp}:
    Delete reserve_tag pragmas from these test cases, and its effects
    from the expected outputs.

tests/invalid/bad_foreign_type.err_exp:
tests/invalid/bigtest.err_exp:
tests/invalid/foreign_enum_invalid.err_exp:
tests/invalid/type_lhs_var.err_exp:
tests/invalid/uu_type.err_exp:
tests/invalid/where_abstract_enum.err_exp:
tests/invalid/where_direct_arg.err_exp:
    Expect the updated messages for some errors.

tests/valid/Mmake.valid.common:
tests/valid/Mmakefile:
    Disable any reserve_tag test cases, as they are not applicable anymore.
2018-01-31 17:54:40 +11:00
Julien Fischer
f519e26173 Add builtin 64-bit integer types -- Part 1.
Add the new builtin types: int64 and uint64.

Support for these new types will need to be bootstrapped over several changes.
This is the first such change and does the following:

- Extends the compiler to recognise 'int64' and 'uint64' as builtin types.
- Extends the set of builtin arithmetic, bitwise and relational operators
  to cover the new types.
- Adds the new internal option '--unboxed-int64s' to the compiler; this will be
  used to control whether 64-bit integer types are boxed or not.
- Extends all of the code generators to handle the new types.
- Extends the runtimes to support the new types.
- Adds new modules to the standard library intend to contain basic operations
  on the new types.  (These are currently empty and not documented.)

There are bunch of limitations marks with "XXX INT64"; these will be lifted in
part 2 of this change.  Also, 64-bit integer types are currently always boxed,
again this limitation will be lifted in later changes.

compiler/options.m:
    Add the new option --unboxed-int64s.

compiler/prog_type.m:
compiler/prog_data.m:
compiler/builtin_lib_types.m:
     Recognise int64 and uint64 as builtin types.

compiler/builtin_ops.m:
     Add builtin operations for the new types.

compiler/hlds_data.m:
     Add new tag types for the new types.

compiler/ctgc.selector.m:
compiler/dead_proc_elim.m:
compiler/export.m:
compiler/foreign.m:
compiler/goal_util.m:
compiler/higher_order.m:
compiler/hlds_code_util.m:
compiler/hlds_dependency_graph.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/implementation_defined_literals.m:
compiler/inst_check.m:
compiler/mercury_to_mercury.m:
compiler/mode_util.m:
compiler/module_qual.qualify_items.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/parse_tree_to_term.m:
compiler/parse_type_name.m:
compiler/polymorphism.m:
compiler/prog_out.m:
compiler/prog_util.m:
compiler/rbmm.execution_path.m:
compiler/rtti.m:
compiler/table_gen.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the above changes to the parse tree and HLDS.

compiler/c_util.m:
    Support writing out constants of the new types.

compiler/llds.m:
    Add a representation for constants of the new types to the LLDS.

compiler/stack_layout.m:
    Add a new field to the stack layout params that records whether
    64-bit integers are boxed or not.

compiler/call_gen.:m
compiler/code_info.m:
compiler/disj_gen.m:
compiler/dupproc.m:
compiler/exprn_aux.m:
compiler/global_data.m:
compiler/jumpopt.m:
compiler/llds_out_data.m:
compiler/llds_out_instr.m:
compiler/lookup_switch.m:
compiler/mercury_compile_llds_back_end.m:
compiler/prog_rep.m:
compiler/prog_rep_tables.m:
compiler/var_locn.m b/compiler/var_locn.m:
    Support the new types in the LLDS code generator.

compiler/mlds.m:
    Support constants of the new types in the MLDS.

compiler/ml_call_gen.m:
compiler/ml_code_util.m:
compiler/ml_global_data.m:
compiler/ml_rename_classes.m:
compiler/ml_top_gen.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen.m:
compiler/ml_util.m:
compiler/mlds_to_target_util.m:
compiler/rtti_to_mlds.m:
     Conform to the above changes to the MLDS.

compiler/mlds_to_c.m:
compiler/mlds_to_cs.m:
compiler/mlds_to_java.m:
    Generate the appropriate target code for constants of the new types
    and operations involving them.

compiler/bytecode.m:
compiler/bytecode_gen.m:
    Handle the new types in the bytecode generator; we just abort if we
    encounter them for now.

compiler/elds.m:
compiler/elds_to_erlang.m:
compiler/erl_call_gen.m:
compiler/erl_code_util.m:
compiler/erl_unify_gen.m:
    Handle the new types in the Erlang code generator.

library/private_builtin.m:
    Add placeholders for the builtin unify and compare operations for
    the new types.  Since the bootstrapping compiler will not recognise
    the new types we give them polymorphic arguments.  These can be
    replaced after this change has bootstrapped.

    Update the Java list of TypeCtorRep constants here.

library/int64.m:
library/uint64.m:
    New modules that will eventually contain builtin operations on the new
    types.

library/library.m:
library/MODULES_UNDOC:
    Do not include the above modules in the library documentation for now.

library/construct.m:
library/erlang_rtti_implementation.m:
library/rtti_implementation.m:
library/table_statistics.m:
deep_profiler/program_representation_utils.m:
mdbcomp/program_representation.m:
    Handle the new types.

configure.ac:
runtime/mercury_conf.h.in:
    Define the macro MR_BOXED_INT64S.  For now it is always defined, support for
    unboxed 64-bit integers will be enabled in a later change.

runtime/mercury_dotnet.cs.in:
java/runtime/TypeCtorRep.java:
runtime/mercury_type_info.h:
    Update the list of type_ctor reps.

runtime/mercury.h:
runtime/mercury_int.[ch]:
    Add macros for int64 / uint64 -> MR_Word conversion, boxing and
    unboxing.

    Add functions for hashing 64-bit integer types suitable for use
    with the tabling mechanism.

runtime/mercury_tabling.[ch]:
    Add additional HashTableSlot structs for 64-bit integer types.

    Omit the '%' character from the conversion specifiers we pass via
    the 'key_format' argument to the macros that generate the table lookup
    function.  This is so we can use the C99 exact size integer conversion
    specifiers (e.g. PRIu64 etc.) directly here.

runtime/mercury_hash_lookup_or_add_body.h:
    Add the '%' character that was omitted above to the call to debug_key_msg.

runtime/mercury_memory.h:
     Add new builtin allocation sites for boxed 64-bit integer types.

runtime/mercury_builtin_types.[ch]:
runtime/mercury_builitn_types_proc_layouts.h:
runtime/mercury_construct.c:
runtime/mercury_deconstruct.c:
runtime/mercury_deep_copy_body.h:
runtime/mercury_ml_expand_body.h:
runtime/mercury_table_type_body.h:
runtime/mercury_tabling_macros.h:
runtime/mercury_tabling_preds.h:
runtime/mercury_term_size.c:
runtime/mercury_unify_compare_body.h:
    Add the new builtin types and handle them throughout the runtime.

runtime/Mmakefile:
    Add mercury_int.c to the list of .c files.

doc/reference_manual.texi:
     Add the new types to the list of reserved type names.

     Add the mapping from the new types to their target language types.
     These are commented out for now.
2018-01-12 09:29:24 -05:00
Julien Fischer
8a240ba3f0 Add builtin 8, 16 and 32 bit integer types -- Part 1.
Add the new builtin types: int8, uint8, int16, uint16, int32 and uint32.
Support for these new types will need to be bootstrapped over several changes.
This is the first such change and does the following:

- Extends the compiler to recognise 'int8', 'uint8', 'int16', 'uint16', 'int32'
  and 'uint32' as builtin types.
- Extends the set of builtin arithmetic, bitwise and relational operators to
  cover the new types.
- Extends all of the code generators to handle new types.  There currently lots
  of limitations and placeholders marked by 'XXX FIXED SIZE INT'.  These will
  be lifted in later changes.
- Extends the runtimes to support the new types.
- Adds new modules to the standard library intended to hold the basic
  operations on the new types.  (These are currently empty and not documented.)

This change does not introduce the two 64-bit types, 'int64' and 'uint64'.
Their implementation is more complicated and is best left to a separate change.

compiler/prog_type.m:
compiler/prog_data.m:
compiler/builtin_lib_types.m:
    Recognise int8, uint8, int16, uint16, int32 and uint32 as builtin types.

    Add new type, int_type/0,that enumerates all the possible integer types.

    Extend the cons_id/0 type to cover the new types.

compiler/builtin_ops.m:
    Parameterize the integer operations in the unary_op/0 and binary_op/0
    types by the new int_type/0 type.

    Add builtin operations for all the new types.

compiler/hlds_data.m:
    Add new tag types for the new types.

compiler/hlds_pred.m:
    Parameterize integers in the table_trie_step/0 type.

compiler/ctgc.selector.m:
compiler/dead_proc_elim.m:
compiler/export.m:
compiler/foreign.m:
compiler/goal_util.m:
compiler/higher_order.m:
compiler/hlds_code_util.m:
compiler/hlds_dependency_graph.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/implementation_defined_literals.m:
compiler/inst_check.m:
compiler/mercury_to_mercury.m:
compiler/mode_util.m:
compiler/module_qual.qualify_items.m:
compiler/opt_debug.m:
compiler/opt_util.m:
compiler/parse_tree_out_info.m:
compiler/parse_tree_to_term.m:
compiler/parse_type_name.m:
compiler/polymorphism.m:
compiler/prog_out.m:
compiler/prog_rep.m:
compiler/prog_rep_tables.m:
compiler/prog_util.m:
compiler/rbmm.exection_path.m:
compiler/rtti.m:
compiler/rtti_to_mlds.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/type_constraints.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the above changes to the parse tree and HLDS.

compiler/c_util.m:
    Support generating the builtin operations for the new types.

doc/reference_manual.texi:
    Add the new types to the list of reserved type names.

    Add the mapping from the new types to their target language types.
    These are commented out for now.

compiler/llds.m:
    Replace the lt_integer/0 and lt_unsigned functors of the llds_type/0,
    with a single lt_int/1 functor that is parameterized by the int_type/0
    type.

    Add a representations for constants of the new types to the LLDS.

compiler/call_gen.m:
compiler/dupproc.m:
compiler/exprn_aux.m:
compiler/global_data.m:
compiler/jumpopt.m:
compiler/llds_out_data.m:
compiler/llds_out_global.m:
compiler/llds_out_instr.m:
compiler/lookup_switch.m:
compiler/middle_rec.m:
compiler/peephole.m:
compiler/pragma_c_gen.m:
compiler/stack_layout.m:
compiler/string_switch.m:
compiler/switch_gen.m:
compiler/tag_switch.m:
compiler/trace_gen.m:
compiler/transform_llds.m:
    Support the new types in the LLDS code generator.

compiler/mlds.m:
    Support constants of the new types in the MLDS.

compiler/ml_accurate_gc.m:
compiler/ml_call_gen.m:
compiler/ml_code_util.m:
compiler/ml_disj_gen.m:
compiler/ml_foreign_proc_gen.m:
compiler/ml_global_data.m:
compiler/ml_lookup_switch.m:
compiler/ml_simplify_switch.m:
compiler/ml_string_switch.m:
compiler/ml_switch_gen.m:
compiler/ml_tailcall.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen.m:
compiler/ml_util.m:
compiler/mlds_to_target_util.m:
    Conform to the above changes to the MLDS.

compiler/mlds_to_c.m:
compiler/mlds_to_cs.m:
compiler/mlds_to_java.m:
    Generate the appropriate target code for constants of the new
    types and operations involving them.

compiler/bytecode.m:
compiler/bytecode_gen.m:
    Handle the new types in the bytecode generator; we just abort if we
    encounter them for now.

compiler/elds.m:
compiler/elds_to_erlang.m:
compiler/erl_call_gen.m:
compiler/erl_code_util.m:
compiler/erl_rtti.m:
compiler/erl_unify_gen.m:
    Handle the new types in the Erlang code generator.

library/private_builtin.m:
    Add placeholders for the builtin unify and compare operations for
    the new types.  Since the bootstrapping compiler will not recognise
    the new types we give the polymorphic arguments.  These can be
    replaced after this change has bootstrapped.

    Update the Java list of TypeCtorRep constants.

library/int8.m:
library/int16.m:
library/int32.m:
library/uint8.m:
library/uint16.m:
library/uint32.m:
    New modules that will eventually contain builtin operations
    on the new types.

library/library.m:
library/MODULES_UNDOC:
    Do not include the above modules in the library documentation
    for now.

library/construct.m:
library/erlang_rtti_implementation.m:
library/rtti_implementation.m:
deep_profiler/program_representation_utils.m:
mdbcomp/program_representation.m:
    Handle the new types.

runtime/mercury_dotnet.cs.in:
java/runtime/TypeCtorRep.java:
runtime/mercury_type_info.h:
    Update the list of TypeCtorReps.

configure.ac:
runtime/mercury_conf.h.in:
    Check for the header stdint.h.

runtime/mercury_std.h:
    Include stdint.h; abort if that header is no present.

runtime/mercury_builtin_types.[ch]:
runtime/mercury_builtin_types_proc_layouts.h:
runtime/mercury_construct.c:
runtime/mercury_deconstruct.c:
runtime/mercury_deep_copy_body.h:
runtime/mercury_ml_expand_body.h
runtime/mercury_table_type_body.h:
runtime/mercury_tabling_macros.h:
runtime/mercury_tabling_preds.h:
runtime/mercury_term_size.c:
runtime/mercury_unify_compare_body.h:
    Add the new builtin types and handle them throughout the runtime.
2017-07-18 01:31:01 +10:00
Zoltan Somogyi
2ac8465659 Make the code adding new types to the HLDS readable.
The motivation for this diff was that I wanted the compiler to generate
a warning if a module declared the same type twice. (During the cleanup
of unify_proc.m I did recently, I found and fixed such a duplicate
declaration.)

compiler/add_type.m:
    The old code of module_add_type_defn was not just long (210+ lines),
    it is also very complex.

    Part of this complexity was sort-of justified. It dealt with adding
    three separate kinds of item_type_defns: abstract type "definitions",
    which are actually declarations; the definitions of Mercury types,
    and the definitions of foreign types. A single type could have more than
    one of these (e.g. declaration and a definition, or a Mercury definition
    and a foreign definition), and it had to be prepared to process these
    in any order.

    Part of this complexity was self-inflicted. The parts of the predicate
    that dealt with the same kind of definition were not always next to each
    other, and for some parts, it wasn't even clear *what* kind of definition
    it was dealing with. It did the same tests on both the old and updated
    versions of definitions, when those definitions were guaranteed to be
    identical; the "updating" predicate was a no-op. And it used completely
    different code for detecting and handling related errors.

    This diff fixes the above problems. It separates the task of adding
    an item_type_defn to the HLDS into three subtasks, done in three separate
    predicates: adding type declarations, adding Mercury definitions, and
    adding foreign definitions. It specializes each predicate to its task,
    and simplifies its decision flow. It also delegates the creation of
    (most) error messages to separate predicates. Together, these changes
    make each of module_add_type_defn_{abstract,mercury,foreign} easily
    understandable.

    Generate a warning if a type is declared twice, i.e. if e.g.
    ":- type x." is followed by another ":- type x.".

    Call module_info_incr_errors to register the presence of errors in just
    one central place. (Before, some of the places that generated error
    messages incremented the error count, and some places didn't.)

    Improve the wording of some error messages.

    Refer to type names in error messages by unqualified sym_names
    in cases where the module qualifier being elided is obvious from
    the name of the module being compiled.

    Add documentation.

    Add descriptions of potential future improvements.

    Add some XXXs at places that I think deserve them.

    Give some predicates and variables better names.

compiler/prog_data.m:
    Change the parse tree representation of type definitions by
    explicitly specifying a type for storing the contents of each kind
    of type definition.

compiler/hlds_data.m:
    Give a predicate a better name.

    Use one of the new types in prog_data.m in the HLDS version of type
    definitions, to minimize differences between the parse tree and HLDS
    versions.

compiler/add_foreign_enum.m:
compiler/add_pragma.m:
compiler/add_special_pred.m:
compiler/check_typeclass.m:
compiler/du_type_layout.m:
compiler/equiv_type.m:
compiler/equiv_type_hlds.m:
compiler/foreign.m:
compiler/get_dependencies.m:
compiler/hlds_code_util.m:
compiler/hlds_out_module.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/item_util.m:
compiler/make_hlds_passes.m:
compiler/make_hlds_separate_items.m:
compiler/make_tags.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen.m:
compiler/module_qual.qualify_items.m:
compiler/parse_pragma.m:
compiler/parse_tree_out.m:
compiler/parse_type_defn.m:
compiler/post_term_analysis.m:
compiler/recompilation.check.m:
compiler/recompilation.usage.m:
compiler/recompilation.version.m:
compiler/resolve_unify_functor.m:
compiler/simplify_goal_ite.m:
compiler/special_pred.m:
compiler/switch_util.m:
compiler/term_norm.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
    Conform to the changes in prog_data.m.

library/io.m:
library/store.m:
    Delete duplicate type declarations that add_type.m now complains about.

tests/invalid/bad_foreign_type.{m,err_exp}:
    Extend this test to test the new warning.

    Expect the updated versions of some error messages.

tests/invalid/extra_info_prompt.err_exp:
tests/invalid/foreign_type_visibility.err_exp:
tests/invalid/user_eq_dummy.err_exp:
    Expect the updated versions of some error messages.
2017-06-27 18:15:58 +02:00
Zoltan Somogyi
1af5bcf2f1 Make module_name_to_file_name currying-friendly.
compiler/file_names.m:
    Change the order of arguments of module_name_to_file_name and related
    predicates to make it easier to construct closures from them. Delete
    the previous higher-order-friendly versions, which the previous step
    has made unnecessary.

compiler/compile_target_code.m:
compiler/elds_to_erlang.m:
compiler/export.m:
compiler/find_module.m:
compiler/generate_dep_d_files.m:
compiler/intermod.m:
compiler/llds_out_file.m:
compiler/make.m:
compiler/make.module_dep_file.m:
compiler/make.module_target.m:
compiler/make.program_target.m:
compiler/make.util.m:
compiler/mercury_compile_front_end.m:
compiler/mercury_compile_llds_back_end.m:
compiler/mercury_compile_main.m:
compiler/mercury_compile_middle_passes.m:
compiler/mercury_compile_mlds_back_end.m:
compiler/mlds_to_c.m:
compiler/mlds_to_cs.m:
compiler/mlds_to_java.m:
compiler/mmc_analysis.m:
compiler/mode_constraints.m:
compiler/module_cmds.m:
compiler/modules.m:
compiler/read_modules.m:
compiler/recompilation.check.m:
compiler/recompilation.usage.m:
compiler/write_deps_file.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
    Conform to the change above. In several places, this means replacing
    explicit lambda expressions with simple partial application of the
    relevant predicates.
2017-06-12 19:38:20 +02:00
Zoltan Somogyi
e5f5005703 Replace two types isomorphic to pred_proc_id with pred_proc_id.
compiler/hlds_data.m:
    Delete the hlds_class_proc type, and replace its uses with pred_proc_id.

compiler/hlds_pred.m:
    Add utility functions to project the pred_id and proc_id parts
    of a pred_proc_id.

compiler/add_class.m:
compiler/add_pred.m:
compiler/base_typeclass_info.m:
compiler/check_typeclass.m:
compiler/dead_proc_elim.m:
compiler/float_regs.m:
compiler/higher_order.m:
compiler/hlds_out_module.m:
compiler/intermod.m:
compiler/polymorphism.m:
compiler/type_class_info.m:
compiler/type_constraints.m:
compiler/xml_documentation.m:
    Replace both hlds_class_procs, and simple pairs of pred_ids and proc_ids,
    with uses of pred_proc_id, the type that was designed for this purpose.
2017-04-03 14:03:45 +10:00
Julien Fischer
092e175f45 Add a builtin unsigned word sized integer type -- Part 1.
Add a new builtin type: uint, which is an unsigned word sized integer type.
Support for this new type will need be bootstrapped over several changes.
This is the first such change and does the following:

- Extends the compiler to recognize 'uint' as a builtin type.
- Extends the set of builtin operations to include relational and (some)
  arithmetic operations on uints.
- Extends all of the code generators to handle the above.  There are some
  limitations currently marked by 'XXX UINT'.  These will be lifted once
  the compiler recognised uint and additional library support becomes
  available.
- Extends the runtime to support uints.

compiler/prog_type.m:
compiler/prog_data.m:
compiler/builtin_lib_types.m:
    Recognize uint as a builtin type.

    Add a new alternative to the cons_id/0 type corresponding to the uint type
    -- for bootstrapping purposes its argument is currently an int.

compiler/builtin_ops.m:
    Add builtin relational and arithmetic operations on uints.  Note that the
    existing 'unsigned_le' operation is actually intended for use with signed
    values.  Rather than attempt to modify its meaning, I have just added new
    operations specific to the uint type.

compiler/hlds_data.m:
    Add a new tag type for uints.

compiler/type_ctor_info.m:
    Recognise uint as a builtin.

    Bump the RTTI version number here.

compiler/ctgc.selector.m:
compiler/dead_proc_elim.m:
compiler/dependency_graph.m:
compiler/export.m:
compiler/foreign.m:
compiler/goal_util.m:
compiler/higher_order.m:
compiler/hlds_code_util.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/hlds_pred.m:
compiler/implementation_defined_literals.m:
compiler/inst_check.m:
compiler/mercury_to_mercury.m:
compiler/mode_util.m:
compiler/module_qual.qualify_items.m:
compiler/parse_tree_to_term.m:
compiler/parse_type_name.m:
compiler/polymorphism.m:
compiler/prog_out.m:
compiler/prog_rep.m:
compiler/prog_rep_tables.m:
compiler/prog_util.m:
compiler/rbmm.execution_path.m:
compiler/rtti.m:
compiler/special_pred.m:
compiler/switch_gen.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/type_constraints.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/unify_gen.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
    Conform to the above changes to the parse tree and HLDS.

compiler/c_util.m:
    Support generating builtin operations for uints.

compiler/llds.m:
    Add a representation for uint constants to the LLDS.

    Map uints onto MR_Unsigned.

compiler/call_gen.m:
compiler/dupproc.m:
compiler/exprn_aux.m:
compiler/global_data.m:
compiler/jumpopt.m:
compiler/llds_out_data.m:
compiler/llds_out_instr.m:
compiler/opt_debug.m:
compiler/opt_util.m:
    Support uints in the LLDS code generator.

compiler/mlds.m:
     Support uint constants in the MLDS.

compiler/ml_accurate_gc.m:
compiler/ml_call_gen.m:
compiler/ml_global_data.m:
compiler/ml_simplify_switch.m:
compiler/ml_switch_gen.m:
compiler/ml_tailcall.m:
compiler/ml_type_gen.m:
compiler/ml_unify_gen.m:
compiler/ml_util.m:
compiler/rtti_to_mlds.m:
    Conform to the above change to the MLDS.

compiler/mlds_to_c.m:
compiler/mlds_to_java.m:
compiler/mlds_to_cs.m:
     Generate the appropriate target code for uint constants and uint
     relational operations.

compiler/bytecode.m:
compiler/bytecode_gen.m:
     Handle uints in the bytecode generator: we just abort if we
     encounter them for now.

compiler/elds.m:
compiler/elds_to_erlang.m:
compiler/erl_call_gen.m:
compiler/erl_code_util.m:
compiler/erl_rtti.m:
compiler/erl_unify_gen.m:
    Handle uints in the Erlang code generator.

library/private_builtin.m:
    Add placeholders for builtin_{unify,compare}_uint.  Since the
    bootstrapping compiler will not recognize uint as a type, we
    give them polymorphic arguments.  These can be replaced after
    this change has bootstrapped.

    Update the Java list of TypeCtorRep constants, which for some
    reason is defined here.

library/uint.m:
    New module that will eventually contain operations on uints.

library/MODULES_DOCS:
library/library.m:
     Add the uint module.

library/construct.m:
library/erlang_rtti_implementation.m:
library/rtti_implementation.m:
mdbcomp/program_representation.m:
     Handle uints.

deep_profiler/program_representation_utils.m:
     Conform to the above change.

runtime/mercury_dotnet.cs.in:
     Update the list of TypeCtorReps for C#

java/runtime/TypeCtorRep.java:
     Update this, although the actual TypeCtorRep constants
     are defined the library.

runtime/mercury_type_info.h:
    Bump the RTTI version number.

    Add an alternative for uints to the tyepctor rep enum.

runtime/mercury_builtin_types.{h,c}:
runtime/mercury_builtin_types_proc_layouts.h:
runtime/mercury_deconstruct.c:
runtime/mercury_deep_copy_body.h:
runtime/mercury_table_type_body.h:
runtime/mercury_tabling.h:
runtime/mercury_tabling_macros.h:
runtime/mercury_unify_compare_body.h:
    Add uint as a builtin type and handle it throughout the runtime.

runtime/mercury_grade.h:
    Bump the binary compatibility version.

runtime/mercury_term_size.c:
runtime/mercury_ml_expand_body.h:
    Handle uint and fix probable bugs with the handling of ints on
    64-bit Windows.
2016-10-24 12:55:35 +11:00
Zoltan Somogyi
cfcfde1db7 Simplify the representation of modes of unifications.
Unifications (x = y) have long had two descriptions of their modes.
One is the unify_mode, which used to look like this:
    (initx -> finalx) - (inity -> finaly)
and other is the uni_mode, which used to look like this:
    (initx - inity) -> (finalx - finaly)
Each unification had one unify_mode, and each unification that includes
a function symbol had one uni_mode per argument of that function symbol.

The two forms of mode information looked similar enough to be easily
confusable, but were subtly different. As it turns out, there was no
particular reason for the difference, so this diff eliminates the
uni_mode type, and the difference along with it.

What rationale there was for the uni_mode type was that the two modes
it represented (one for each side of the unification) both had their
initial and final insts directly available. This is not true for modes
in general: a value of the mer_mode type could have the form
"InitInst -> FinalInst" (which this diff renames "from_to_mode(InitInst,
FinalInst)", but could also be a "user_defined_inst(...)", which required
a table lookup to turn it into an initial/final pair of insts. This matters,
because almost all code that processes the modes of unifications
works with the initial and final insts.

This diff therefore creates a new type, from_to_insts, which represents
mode information only in the form of terms such as "from_to_insts(InitInst,
FinalInst)", and makes a unify_mode take two values of this type, not mer_mode,
as arguments.

As discussed on m-rev, this diff also renames the old, deceptively named
"arg_mode" type: its new name is "top_functor_mode".

compiler/prog_data.m:
compiler/hlds_goal.m:
    As mentioned above, avoid using "->" as a function symbol, and replace
    both -> and - with bespoke function symbols.

compiler/mode_util.m:
    Add some utility predicates and functions on the new types, and
    delete the old utility routines that operated on uni_modes.

    Code that uses the new functions and predicates should have a higher level
    of abstraction than the code that used to do the same job "manually".

compiler/*.m:
    Conform to the changes above, using the new utility predicates and
    functions where relevant. In several cases, this required fixing
    confusion of the kind described at the top. In all but one case,
    the confusion affected only variable names, but in one case,
    deconstruct_functor in make_goal.m, it caused a bug. The bug has
    had no effect up till now because deconstruct_functor is called
    only from three places: try_expand.m, stm_expand.m, and untupling.m.
    The incorrect mode (which was the nonsensical ground -> free)
    generated by the code of try_expand.m itself was discarded and
    overwritten when try_expand.m invoked the modechecker. (I don't
    know whether this bugfix makes that invocation redundant or not.)
    The other two modules, stm_expand.m and untupling.m, may do something
    similar, but in any case, they don't yet work for other reasons.
    (A bootcheck with --untupling causes a compiler abort when compiling
    deep_profiler/query.m in stage 2 both without and with this fix.)

    Delete no-longer-needed imports of the pair module (and of some other
    modules).

    Put the arguments of some predicates into a more logical order.

    In bytecode_gen.m, replace clauses with disjunctions, and delete the
    arguments that this step has revealed to be unused.
2016-05-19 10:43:24 +10:00
Paul Bone
652d89cf38 Add take_while and drop_while to the list module
Add new predicates and functions take_while and drop_while to the list
module.

Deprecate takewhile/4, replacing it with take_while/4.

library/list.m:
    As above.

NEWS:
    Announce this change.

browser/parse.m:
compiler/compute_grade.m:
compiler/deforest.m:
compiler/mercury_compile_main.m:
compiler/ml_optimize.m:
compiler/mode_robdd.equiv_vars.m:
compiler/options_file.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.domain.m:
compiler/structure_sharing.domain.m:
compiler/term_constr_data.m:
compiler/write_deps_file.m:
compiler/xml_documentation.m:
deep_profiler/read_profile.m:
deep_profiler/top_procs.m:
library/list.m:
    Conform to above changes.
2016-04-22 21:27:03 +10:00
Mark Brown
3acbf03059 Implement combined higher-order types and insts.
These allow types to be defined in the following manner:

    :- type job ---> job(pred(int::out, io::di, io::uo) is det).

For any construction unification using this functor the argument must
have the required higher-order inst; it is a mode error if it does not.
When terms of type job with inst ground are deconstructed, the argument
is inferred to have the given inst, allowing a higher-order call in that
mode.

The new type syntax is currently only permitted as the direct argument of
a functor in a du type definition. In future it would be meaningful to
support this syntax in other locations, but that is left for a separate
change.

In order to correctly implement the construct/3 library predicate, we
need to be able to dynamically check that arguments do not violate
any constraints on the argument insts. At the moment, we conservatively
abort if any such constraints are present irrespective of whether they
are satisfied or not. Since these constraints are a new feature, no
existing code will abort in this way.

The implementation refers to the inst information associated with types
as "subtype information". This is because, generally, we think of the
combination of a type with a fully bound inst (i.e., one that describes
terms that contain no unbound variables) describes a subtype of that type.

compiler/inst_util.m:
	Ensure that arguments have the necessary insts in construction
	unifications.

	Where available, propagate the insts into arguments rather than
	using ground(shared, none).

compiler/prog_io_type_name.m:
	Parse the new form of types.

compiler/unparse.m:
	Unparse the new form of types.

compiler/prog_io_type_defn.m:
	Allow the new form of types in functor arguments.

compiler/prog_ctgc.m:
compiler/prog_io_item.m:
compiler/prog_io_mutable.m:
compiler/prog_io_pragma.m:
compiler/prog_io_typeclass.m:
compiler/superhomogeneous.m:
	Disallow the new form of types in places other than functor
	arguments.

compiler/prog_data.m:
	Go back to representing function types with result type appended
	to the arguments. In most case this now results in simpler code.

compiler/prog_type.m:
	Abstract away the representation of predicate vs function arguments
	by using a predicate to construct these types.

compiler/rtti.m:
compiler/type_ctor_info.m:
	Include subtype information about the arguments of a du functor
	and about the argument of a notag functor. Generate this
	information from the argument types.

	Currently, the information is one bit which says whether or not
	any subtypes exist in the arguments.

	Bump the RTTI version number from the compiler side.

compiler/rtti_out.m:
	Output functor subtype information for the low-level C backend.

compiler/rtti_to_mlds.m:
	Include functor subtype information in the MLDS.

compiler/mlds_to_cs.m:
	Add the new runtime type to the special cases.

compiler/erl_rtti.m:
compiler/erlang_rtti.m:
library/erlang_rtti_implementation.m:
	Include functor subtype info in the erlang RTTI.

java/runtime/DuFunctorDesc.java:
java/runtime/FunctorSubtypeInfo.java:
	Include functor subtype information in the Java runtime.

runtime/mercury_dotnet.cs.in:
	Include functor subtype information in the C# runtime.

runtime/mercury_type_info.h:
	Include functor subtype information in the C runtime.

	Bump the RTTI version number in the runtime.

	Define macros to access the new field. These macros can correctly
	handle the previous RTTI version, therefore we do not need to
	change the minimum version at this time.

library/private_builtin.m:
	Define constants for use by the Java backend.

library/construct.m:
library/rtti_implementation.m:
	Use the new RTTI to ensure we don't attempt to construct terms
	that violate the new insts.

compiler/prog_rep_tables.m:
	Ignore the new inst info for now.

compiler/*.m:
	Changes to conform to above.

doc/reference_manual.texi:
	Document the new feature.

tests/hard_coded/functor_ho_inst.{m,exp}:
tests/hard_coded/functor_ho_inst_2.{m,exp}:
tests/hard_coded/functor_ho_inst_excp.{m,exp}:
tests/hard_coded/functor_ho_inst_excp_2.{m,exp}:
	Test the new functionality.

tests/invalid/combined_ho_type_inst.{m,err_exp}:
tests/invalid/combined_ho_type_inst_2.{m,err_exp}:
	Test that we don't allow the new types where they are not permitted,
	or are incomplete.

tests/invalid/functor_ho_inst_bad.{m,err_exp}:
tests/invalid/functor_ho_inst_bad_2.{m,err_exp}:
tests/invalid/functor_ho_inst_bad_3.{m,err_exp}:
	Test that the argument inst information is enforced as required.

tests/hard_coded/Mmakefile:
tests/invalid/Mmakefile:
	Run the new test cases.
2016-02-08 16:09:01 +11:00
Zoltan Somogyi
bc6cfcd9bd Add consider_used pragmas for may-be-needed-later predicates.
Delete some other predicates that won't be needed later.
2015-12-28 21:06:03 +11:00
Julien Fischer
94535ec121 Fix spelling and formatting throughout the system.
configure.ac:
browser/*.m:
compiler/*.m:
deep_profiler/*.m:
library/*.m:
ssdb/*.m:
runtime/mercury_conf.h.in:
runtime/*.[ch]:
scripts/Mmake.vars.in:
trace/*.[ch]:
util/*.c:
	Fix spelling and doubled-up words.

	Delete trailing whitespace.

	Convert tabs into spaces (where appropriate).
2015-12-02 18:46:14 +11:00
Zoltan Somogyi
5de235065d Fix too-long lines. 2015-11-16 00:09:26 +11:00
Zoltan Somogyi
b68abc9be7 Use a kind-specific status type for insts and modes.
compiler/status.m:
    Change the inst_status and mode_status types so that instead of just
    being synonyms for old_import_status, they are now a pair of an
    old_import_status and a new type, new_instmode_status, which should
    eventually become the status type for insts and modes (hence the name).

    Delete the unused operations on inst_statuses and mode_statuses.
    For the rest, modify them so that they are done on both the
    old_import_status half and the new_instmode_status status half,
    and abort if they get different answers.

compiler/hlds_out_module.m:
    Print out the status of each inst and mode in HLDS dumps,
    if the inst table and mode table are being dumped.

compiler/prog_item.m:
    Rename import_locn_ancestor to import_locn_import_by_ancestor,
    since this prevents ambiguity: the former can be interpreted to mean
    that the imported module is an implicit-imported ancestor.

compiler/add_mode.m:
compiler/hlds_out_util.m:
compiler/intermod.m:
compiler/make_hlds_passes.m:
compiler/module_qual.m:
compiler/modules.m:
compiler/xml_documentation.m:
    Conform to the changes above, duplicating and cross-checking
    each operation as needed.
2015-09-20 13:36:06 +10:00
Zoltan Somogyi
656493dfdf Use separate types for the status of different entity kinds.
We used the old import_status type to represent the status of six different
kinds of entities:

- types
- insts
- modes
- typeclasses
- instances
- predicates

even though some statuses that made sense for one kind of entity didn't for
another another (e.g. predicates can be pseudo imported/exported, but the
other five kinds of entities cannot).

Create the new types type_status, inst_status, ..., pred_status to represent
the status of these entities in the HLDS. For now, these are just wrappers
around the renamed old_import_status type, but I plan to replace them with
status types that *are* specialized to the applicable kind of entity,
along the lines of compiler/notes/status_proposal. This is a necessary
first step towards that proposal.

compiler/status.m:
    Define the six new entity-kind-specific status types, and replicate
    the test predicates that used to work on the import_status type
    to work on these instead.

    Define a status type, item_mercury_status, that contains just the info
    that is common to all entities in an item block, for use during
    the process of adding items to the HLDS.

    Move the predicates that converted section markers to statuses
    from here to make_hlds_passes.m, since that is the only place
    where they are used, or can be used.

    Move the combine_status predicate here from add_type.m, since
    it is needed for combining the statuses of other kinds of entities
    as well, not just types.

compiler/hlds_data.m:
    Change the HLDS types that record the information we have about
    types, du type fields, insts, modes, typeclasses and instances
    to have kind-specific status fields, instead of the old generic
    import_status type.

    Change the prefix on the field names of the hlds_instance_defn type
    to avoid a name clash, and to make them more meaningful.

    Change the prefix on the field names of the hlds_class_defn type
    to make them more meaningful.

compiler/hlds_pred.m:
    Change the HLDS type that records the information we have about predicates
    to have a kind-specific status field, instead of the old generic
    import_status type.

    Update the predicates that test predicate statuses accordingly.

compiler/hlds_module.m:
    Change the HLDS types that record the information we have about
    type constructors to be type_status, not the old generic import_status.

compiler/make_hlds_passes.m:
    As we process each item block, pass along an item_mercury_status
    instead of an import_status. The code used to use only a subset
    of the possible values of the import_status type, since we can never say
    that all the entities in an item block are e.g. pseudo-exported.
    An item_mercury_status has just the information we actually *know*
    about the item block as a whole. We convert the item_mercury_status
    to a kind-specific status if and when we need to, but for several purposes,
    the item_mercury_status is enough on its own.

    In a few cases, add a new predicate to do this conversion.

    Pass the need_qualifier flag separately from the status. It is needed
    in only a few places, but this was not apparent when we always passed it
    around paired with the import_status.

    Move the predicates that converted section markers to statuses
    to here from status.m, since here is the only place where they are used,
    or can be used.

compiler/add_class.m:
    Convert the statuses of typeclasses and instances to the statuses
    of the predicates implementing their virtual and concrete methods.

compiler/check_typeclass.m:
    Simplify some over-complex code.

compiler/add_special_pred.m:
    Convert the statuses of types to the statuses of the predicates
    implementing their unify, index, compare and solver init operations.
    Note some places where the process of this conversion is (to say the least)
    unclear and undocumented.

compiler/hlds_out_util.m:
    Provide utility predicates to print all the new kinds of statuses.
    These replace the old predicate that did the same in hlds_out_pred.m,
    but printing e.g. type statuses in hlds_out_pred doesn't seem right.

compiler/intermod.m:
    Conform to the changes above.

    Consistently use switches on the booleans returned by xxx_status_to_write,
    instead wrapping a semidet predicate around it and calling that.
    The switches yield code that is both smaller and more maintainable.

compiler/make_hlds_error.m:
    Conform to the changes above.

    Delete a simple wrapper predicate that was used only in one place.
    That place now does the wrapping itself.

compiler/qual_info.m:
    Replace the import_status field in the qual_info with a simple
    is_opt_imported/is_not_opt_imported flag, since that was the only
    thing we used the import_status field for.

compiler/accumulator.m:
compiler/add_clause.m:
compiler/add_foreign_enum.m:
compiler/add_foreign_proc.m:
compiler/add_mode.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma.m:
compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_solver.m:
compiler/add_type.m:
compiler/base_typeclass_info.m:
compiler/ctgc.util.m:
compiler/dead_proc_elim.m:
compiler/dep_par_conj.m:
compiler/dependency_graph.m:
compiler/det_report.m:
compiler/elds_to_erlang.m:
compiler/equiv_type_hlds.m:
compiler/erl_code_gen.m:
compiler/export.m:
compiler/float_regs.m:
compiler/higher_order.m:
compiler/hlds_code_util.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/inst_check.m:
compiler/lambda.m:
compiler/lco.m:
compiler/make_hlds.m:
compiler/make_hlds_warn.m:
compiler/make_tags.m:
compiler/ml_proc_gen.m:
compiler/ml_type_gen.m:
compiler/mode_errors.m:
compiler/oisu_check.m:
compiler/par_loop_control.m:
compiler/polymorphism.m:
compiler/post_term_analysis.m:
compiler/post_typecheck.m:
compiler/prop_mode_constraints.m:
compiler/recompilation.usage.m:
compiler/simplify_proc.m:
compiler/smm_common.m:
compiler/special_pred.m:
compiler/ssdebug.m:
compiler/status.m:
compiler/stm_expand.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.versions.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/superhomogeneous.m:
compiler/table_gen.m:
compiler/term_constr_initial.m:
compiler/term_constr_main.m:
compiler/termination.m:
compiler/trace_params.m:
compiler/type_class_info.m:
compiler/type_constraints.m:
compiler/type_ctor_info.m:
compiler/typecheck.m:
compiler/typecheck_info.m:
compiler/typeclasses.m:
compiler/unify_proc.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.
2015-09-12 09:07:45 +10:00
Zoltan Somogyi
ea094b5bb7 Make the import_status type part of the HLDS.
The import_status type was defined in parse_tree.status.m, but it is
not actually used in the parse_tree package. It is used, extensively,
in the hlds package.

compiler/status.m:
compiler/prog_item.m:
compiler/prog_data.m:
    Move the parts of status.m that *are* needed in the parse_tree package
    to modules in that package. The section markers and the import_locn type
    are moved to prog_item.m, while the need_qualifier type is moved to
    prog_data.m.

compiler/parse_tree.m:
compiler/hlds.m:
    Switch the status.m module from being in the parse_tree package
    to being in the hlds package.

compiler/notes/compiler_design.html:
    Document the switch.

compiler/*.m:
    Update import_module declarations as needed after the above change.

    In some places, import parse_tree.prog_item as well as hlds.status,
    even if we are only intested in statuses, because the import_locn type,
    which part of some statuses, *is* used in the parse_tree package,
    and must therefore be defined there. These undesirable dependencies
    will go away when we implement the proposal for purpose-specific status
    types.
2015-09-09 01:47:08 +10:00
Zoltan Somogyi
62ec97d443 Report imports shadowed by other imports.
If a module has two or more import_module or use_module declarations
for the same module, (typically, but not always, one being in its interface
and one in its implementation), generate an informational message about
each redundant declaration if --warn-unused-imports is enabled.

compiler/hlds_module.m:
    We used to record the set of imported/used modules, and the set of
    modules imported/used in the interface of the current module. However,
    these sets

    - did not record the distinction between imports and uses;
    - did not allow distinction between single and multiple imports/uses;
    - did not record the locations of the imports/uses.

    The first distinction was needed only by module_qual.m, which *did*
    pay attention to it; the other two were not needed at all.

    To generate messages for imports/uses shadowing other imports/uses,
    we need all three, so change the data structure storing such information
    for *direct* imports to one that records all three of the above kinds
    of information. (For imports made by read-in interface and optimization
    files, the old set of modules approach is fine, and this diff leaves
    the set of thus *indirectly* imported module names alone.)

compiler/unused_imports.m:
    Use the extra information now available to generate a
    severity_informational message about any import or use that is made
    redundant by an earlier, more general import or use.

    Fix two bugs in the code that generated warnings for just plain unused
    modules.

    (1) It did not consider that a use of the builtin type char justified
    an import of char.m, but without that import, the type is not visible.

    (2) It scanned cons_ids in goals in procedure bodies, but did not scan
    cons_ids that have been put into the const_struct_db. (I did not update
    the code here when I added the const_struct_db.)

    Also, add a (hopefully temporary) workaround for a bug in
    make_hlds_passes.m, which is noted below.

    However, there are at least three problems that prevent us from enabling
    --warn-unused-imports by default.

    (1) In some places, the import of a module is used only by clauses for
    a predicate that also has foreign procs. When compiled in a grade that
    selects one of those foreign_procs as the implementation of the predicate,
    the clauses are discarded *without* being added to the HLDS at all.
    This leads unused_imports.m to generate an uncalled-for warning in such
    cases. To fix this, we would need to preserve the Mercury clauses for
    *all* predicates, even those with foreign procs, and do all the semantic
    checks on them before throwing them away. (I tried to do this once, and
    failed, but the task should be easier after the item list change.)

    (2) We have two pieces of code to generate import warnings. The one in
    unused_imports.m operates on the HLDS after type and mode checking,
    while module_qual.m operates on the parse tree before the creation of
    the HLDS. The former is more powerful, since it knows e.g. what types and
    modes are used in the bodies of predicates, and hence can generate warnings
    about an import being unused *anywhere* in a module, as opposed to just
    unused in its interface.

    If --warn-unused-imports is enabled, we will get two separate set of
    reports about an interface import being unused in the interface,
    *unless* we get a type or mode error, in which case unused_imports.m
    won't be invoked. But in case we do get such errors, we don't want to
    throw away the warnings from module_qual.m. We could store them and
    throw them away only after we know we won't need them, or just get
    the two modules to generate identical error_specs for each warning,
    so that the sort_and_remove_dups of the error specs will do the
    throwing away for us for free, if we get that far.

    (3) The valid/bug100.m test case was added as a regression test for a bug
    that was fixed in module_qual.m. However the bug is still present in
    unused_imports.m.

compiler/make_hlds_passes.m:
    Give hlds_module.m the extra information it now needs for each item_avail.

    Add an XXX for a bug that cannot be fixed right now: the setting of
    the status of abstract instances to abstract_imported. (The "abstract"
    part is correct; the "imported" part may not be.)

compiler/intermod.m:
compiler/try_expand.m:
compiler/xml_documentation.m:
    Conform to the change in hlds_module.m.

compiler/module_qual.m:
    Update the documentation of the relationship of this module
    with unused_imports.m.

compiler/hlds_data.m:
    Document a problem with the status of instance definitions.

compiler/hlds_out_module.m:
    Update the code that prints out the module_info to conform to the change
    to hlds_module.m.

    Print status information about instances, which was needed to diagnose
    one of the bugs in unused_imports.m. Format the output for instances
    nicer.

compiler/prog_item.m:
    Add a convenience predicate.

compiler/prog_data.m:
    Remove a type synonym that makes things harder to understand, not easier.

compiler/modules.m:
    Delete an XXX that asks for the feature this diff implements.
    Add another XXX about how that feature could be improved.

compiler/Mercury.options.m:
    Add some more modules to the list of modules on which the compiler
    should be invoked with --no-warn-unused-imports.

compiler/*.m:
library/*.m:
mdbcomp/*.m:
browser/*.m:
deep_profiler/*.m:
mfilterjavac/*.m:
    Delete unneeded imports. Many of these shadow other imports, and some
    are just plain unneeded, as shown by --warn-unused-imports. In a few
    modules, there were a *lot* of unneeded imports, but most had just
    one or two.

    In a few cases, removing an import from a module, because it *itself*
    does not need it, required adding that same import to those of its
    submodules which *do* need it.

    In a few cases, conform to other changes above.

tests/invalid/Mercury.options:
    Test the generation of messages about import shadowing on the existing
    import_in_parent.m test case (although it was also tested very thoroughly
    when giving me the information needed for the deletion of all the
    unneeded imports above).

tests/*/*.{m,*exp}:
    Delete unneeded imports, and update any expected error messages
    to expect the now-smaller line numbers.
2015-08-25 00:38:49 +10:00
Zoltan Somogyi
1f80bf0acd Delete the module_specifier type.
compiler/prog_data.m:
    The module_specifier type was defined to be a synonym for sym_name,
    but the module_name type is meant for the same purposes, and has the
    same definition, so it is redundant. Delete it.

compiler/hlds_module.m:
compiler/hlds_out_module.m:
compiler/intermod.m:
compiler/make_hlds_passes.m:
compiler/prog_io_item.m:
compiler/prog_out.m:
compiler/prog_util.m:
compiler/try_expand.m:
compiler/typecheck_errors.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Replace uses of module_specifier with module_name, not just in types,
    but also in the names of the predicates that operate on them, and in the
    field names that refer to them.

compiler/analysis.file.m:
    Avoid an ambiguity.

compiler/make.module_dep_file.m:
    Delete a commented piece of code.

compiler/mercury_to_mercury.m:
    Delete an unused predicate.
2015-07-23 01:48:32 +10:00
Zoltan Somogyi
f2043fc9bd Replace the item list with more structured ASTs.
The parts of the compiler that run before the HLDS is constructed used to use
a raw list of items to represent source files (.m), interface files (.int0,
.int3, .int2 and .int) and optimization files (.opt, and .trans_opt).
These lists had structure, but this structure was implicit, not explicit,
and its invariants were never really documented.

This diff changes that. It replaces the item list with FIVE separate types.

Three of these each represent the unprocessed content of one file:

- parse_tree_int represents the contents of one interface file;
- parse_tree_opt represents the contents of one optimization file;
- parse_tree_src represents the contents of one source file.

Two of these each represent the processed contents of one or more files:

- raw_compilation_unit represents the contents of one module in a source file.
  (The source file may contain several nested modules; the compilation unit
  represents just one.)
- aug_compilation_unit represents the contents of one module in a source file,
  just like raw_compilation_unit, but it is augmented with the contents of the
  interface and optimization files of the other modules imported (directly or
  indirectly) by the original module.

These five separate concepts all used to be represented by the same type,
list(item), but different invariants applied to the structure of those lists.
The most important of those invariants at least are now explicit in the types.
I think it is entirely possible that there are other invariants I haven't
discovered and documented (for example, .int3 files must have stricter
invariants on what can appear in them than .int files), but discovering
and documenting these should be MUCH easier after this change.

I have marked many further opportunities for improvements with "XXX ITEM_LIST".
Some of these include moving code between modules, and the creation of new
modules. However, I have left acting on those XXXs until later, in order to
keep the size of this diff down as much as possible, for easier reviewing.

compiler/prog_item.m:
    Define the five new AST types described above, and utility predicates
    that operate on them.

    In the rest of this change, I tried, as much as possible, to change
    predicates that used to take item lists as arguments to make them change
    one of these types instead. In many cases, this required putting
    the argument lists of those predicates into a more consistent order.
    (Often, predicates that operated on the contents of the module
    took the name of the module and the list of items in the module
    not just as separate arguments, but as separate arguments that
    weren't even next to each other.)

    Define types that identify the different kinds of interface and
    optimization files (.int, .int2 etc). These replace the string suffixes
    we used to use to identify file types. Predicates that used to take strings
    representing suffixes as arguments now have to specify whether they can
    handle all these file types (source, interface and optimization),
    or just (e.g.) all interface file types.

    We used to have items corresponding to `:- module' and `:- end_module'.
    Delete these; this information is now implicit in the structure of the
    relevant AST. The parser handles the corresponding terms as markers,
    not items; these markers are live only during parsing.

    We used to have module_defns corresponding to `:- interface' and
    `:- implementation'. Delete these; this information is now also implicit
    in the structure of the relevant AST. Delete also, for the same reason,
    the module_defns used to mark the starts of sublists in the overall lists
    of items whose items came from the interface files or optimization files
    of other modules. The former are now markers during parsing. The latter
    are never parsed, but are created directly, after parsing has been done.

    Delete the pragma type for `:- pragma source_file'. This is never
    needed later; it is now a marker during parsing.

    Change the internal representation of `:- import' and `:- use'.
    It used to store a list of module names, but that list was an actual list
    only during parsing; after that, it always had exactly one element.
    It now stores one module name, and the parser has a mechanism to convert
    one read-in term to more than one item, for use with terms such as
    `:- import_module a, b'.

    Delete the internal representation of `:- export', which was never
    implemented, since if it IS ever implemented, it will almost certainly
    be in a different form, which will need different support.

    Document some further opportunities for simplification, later.
    (This diff is already more than big enough.)

compiler/prog_io_item.m:
    Rewrite the top-level part of this module. Instead of returning an item
    for every parsed term, distinguish between parsing items that end up
    in item lists inside ASTs, and parsing markers that end up creating
    the STRUCTURE of those ASTs.

compiler/prog_io.m:
    Rewrite the meat of this module. Instead of reading in a simple item list,
    we now have to read in three different parse trees with three different
    grammars, each of which is more complex than a simple list.

compiler/read_modules.m:
    We used to have a map that mapped file names to the contents of those
    files. We now need three separate maps, for interface files, optimization
    files and source files, due to their separate types.
    (We don't actually use the map for optimization files, which seems
    to be a potential performance bug. The root cause of that problem
    us that while intermod.m and the grab_*modules part of modules.m do
    similar jobs, they don't use the same mechanisms.)

    Replace the read_module predicate with the predicates read_module_src
    and read_module_int, since these now return different types.

    To avoid having to create AST-type-specialized variants of
    read_module_ignore_errors and read_module_if_changed, give each of
    read_module_{src,int} arguments that optionally tell them to ignore errors
    and/or to read the module only if changed (though the "and" part of
    "and/or" should not be needed.) These options already existed, but
    they weren't exported.

compiler/timestamp.m:
    Define the type we use for this option in read_modules.

compiler/status.m:
    New module, containing mostly

    - stuff carved out of hlds_pred.m, which defines the import_status type,
      and the predicates that operate on it;
    - stuff carved out of make_hlds_passes.m, which defines the item_status
      type and the predicates that operate on that; and
    - stuff carved out prog_data.m, which defines the section (now
      module_section) and import_locn types.

    It also contains the new section kinds we now use to represent item blocks
    that were imported from interface and optimization files.

compiler/parse_tree.m:
compiler/notes/compiler_design.html:
    Add status.m to the parse_tree package.

compiler/hlds_pred.m:
compiler/prog_data.m:
    Remove the stuff now in status.m.

compiler/error_util.m:
    Provide a mechanism to control the order of messages with respect to
    ALL other messages, not just those that also specify ordering.

compiler/mercury_to_mercury.m:
    Provide predicates for printing out parse_tree_* and *_compilation_unit,
    since printing out a simple item list is no longer enough for debugging.

    Pretty-print type definitions nicely.

    Replace a boolean with a purpose-specific enum.

compiler/modules.m:
    Rewrite virtually all this module to make it work on the new AST
    representations. Generate more detailed error messages for duplicate
    module inclusions. Note lots of possibilities for further improvements,
    including in the documentation. Mark places I am still not sure about,
    especially places where I am not sure *why* the code is doing
    what it is doing.

compiler/module_imports.m:
    This module stores the data structure in which we accumulate the stuff
    imported into a compilation unit, i.e. it is in these data structures
    that a raw_compilation_unit becomes an aug_compilation_unit. Modify
    the data structure and the predicates that operate on it to work on the
    new AST representations, not on an (apparently) simple list of items.

    Avoid ambiguities by adding a prefix to field names.

    Add some convenience predicates.

compiler/module_qual.m:
    Perform module qualification on both raw lists of items (for use when
    generating .int3 files) but also on item blocks (for use pretty much
    in every other situation).

    Generate warnings about module imports that are unnecessarily in the
    module interface using the module's context (the context of the `:- module'
    declaration), not line 1 of the relevant file.

compiler/prog_io_error.m:
    Split some error categories more finely, since some error kinds here
    actually used to be reported for more than one distinct situation.

compiler/prog_io_util.m:
    Provide utility predicates that operate on nonempty lists.

compiler/recompilation.version.m:
    Make the comparison of the old and new contents of the interface file
    work on two parse_tree_ints, not on two raw sequences of items.

    Delete a boolean option that was always `yes', never 'no'.

compiler/recompilation.m:
    Turn some functions into predicates to allow the use of state variable
    notation.

    Avoid ambiguities by adding a prefix to field names.

compiler/write_module_interface_files.m:
    Besides updating the code in this module to work on the new parse tree
    representations, also use cords instead of reversed lists in several cases.
    Note many possibilities for further improvements.

library/list.m:
    Move the type one_or_more here from the compiler directory, since
    we now use it in more than one compiler module, and this is its natural
    home.

mdbcomp/sym_name.m:
    Rename "match_sym_name" to "partial_sym_name_matches_full", since this
    better describes its job.

    Add a det version of sym_name_get_module_name.

compiler/equiv_type.m:
    Rename some types to make them more expressive.

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_foreign_enum.m:
compiler/add_foreign_proc.m:
compiler/add_mode.m:
compiler/add_pragma.m:
compiler/add_pragma_tabling.m:
compiler/add_pred.m:
compiler/add_solver.m:
compiler/add_special_pred.m:
compiler/add_type.m:
compiler/assertion.m:
compiler/base_typeclass_info.m:
compiler/check_typeclass.m:
compiler/ctgc.util.m:
compiler/dead_proc_elim.m:
compiler/dep_par_conj.m:
compiler/dependency_graph.m:
compiler/deps_map.m:
compiler/det_report.m:
compiler/elds_to_erlang.m:
compiler/equiv_type_hlds.m:
compiler/erl_code_gen.m:
compiler/export.m:
compiler/format_call.m:
compiler/higher_order.m:
compiler/hlds_data.m:
compiler/hlds_module.m:
compiler/hlds_out_pred.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/item_util.m:
compiler/lambda.m:
compiler/lco.m:
compiler/make.module_dep_file.m:
compiler/make_hlds.m:
compiler/make_hlds_error.m:
compiler/make_hlds_passes.m:
compiler/make_tags.m:
compiler/mercury_compile.m:
compiler/ml_proc_gen.m:
compiler/ml_type_gen.m:
compiler/mode_errors.m:
compiler/oisu_check.m:
compiler/par_loop_control.m:
compiler/polymorphism.m:
compiler/post_term_analysis.m:
compiler/post_typecheck.m:
compiler/pred_table.m:
compiler/prog_io_dcg.m:
compiler/prog_io_find.m:
compiler/prog_io_pragma.m:
compiler/prog_io_sym_name.m:
compiler/prog_io_type_defn.m:
compiler/prog_io_typeclass.m:
compiler/prop_mode_constraints.m:
compiler/push_goals_together.m:
compiler/qual_info.m:
compiler/recompilation.check.m:
compiler/recompilation.usage.m:
compiler/simplify_proc.m:
compiler/smm_common.m:
compiler/special_pred.m:
compiler/ssdebug.m:
compiler/stm_expand.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.versions.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/table_gen.m:
compiler/term_constr_initial.m:
compiler/term_constr_main.m:
compiler/termination.m:
compiler/trace_params.m:
compiler/trans_opt.m:
compiler/type_class_info.m:
compiler/type_ctor_info.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/typecheck_info.m:
compiler/unify_proc.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
compiler/write_deps_file.m:
compiler/xml_documentation.m:
    Conform to the changes above.

tests/hard_coded/higher_order_func_test.m:
tests/hard_coded/higher_order_syntax.m:
    Avoid a warning about importing a module in the interface, not the
    implementation.

tests/invalid/after_end_module.err_exp:
tests/invalid/any_mode.err_exp:
tests/invalid/bad_end_module.err_exp:
tests/invalid/bigtest.err_exp:
tests/invalid/bug113.err_exp:
tests/invalid/duplicate_modes.err_exp:
tests/invalid/errors.err_exp:
tests/invalid/errors1.err_exp:
tests/invalid/errors2.err_exp:
tests/invalid/funcs_as_preds.err_exp:
tests/invalid/inst_list_dup.err_exp:
tests/invalid/invalid_main.err_exp:
tests/invalid/missing_interface_import2.err_exp:
tests/invalid/no_exports.err_exp:
tests/invalid/occurs.err_exp:
tests/invalid/predmode.err_exp:
tests/invalid/prog_io_erroneous.err_exp:
tests/invalid/type_inf_loop.err_exp:
tests/invalid/typeclass_missing_det_3.err_exp:
tests/invalid/typeclass_test_11.err_exp:
tests/invalid/types.err_exp:
tests/invalid/undef_inst.err_exp:
tests/invalid/undef_mode.err_exp:
tests/invalid/undef_type.err_exp:
tests/invalid/unicode1.err_exp:
tests/invalid/unicode2.err_exp:
tests/invalid/vars_in_wrong_places.err_exp:
tests/warnings/unused_import.exp:
tests/warnings/unused_interface_import.exp:
    Update the expected outputs in the invalid and warnings directories
    to account for one or more of the following five changes.

    Error messages that warn about a module not exporting anything
    used to always refer to line 1 of the module's source file.
    Now expect these messages to refer to the actual context of the module,
    which is the context of its `:- module' declaration.

    Expect a similarly updated context for messages that warn about
    unnecessarily importing modules in the interface, not in the
    implementation.

    Expect a similarly updated context for messages that warn about
    importing a module via both `:- import_module' and `:- use_module'.

    For the modules that follow the `:- module' declaration directly with code,
    also expect an error message about the missing section marker.

    For modules that have terms after the `:- end_module' declaration,
    replace "end_module" with "`:- end_module'" in the error message.

tests/invalid/func_class.{m,err_exp}:
    New test case. It is a copy of the old tests/valid/func_class.m, which
    is missing more than one module marker. The expected output is what I think
    we should generate. The test case currently fails, because we currently
    print only a subset of the expected errors. I am pretty sure the reason
    for that is that old code I have not modified simply throws away the
    missing error messages. Fixing this is work for the near future.

tests/invalid/Mmakefile:
    Enable the new test case.

tests/misc_tests/pretty_print_test.exp:
    Expect the pretty-printed output to use four-space indentation,
    per our current style guide, since the compiler now generates such output.

tests/misc_tests/pretty_print_test.m:
    Clean up the source code of the test as well.

tests/valid/complicated_unify.m:
tests/valid/det_switch.m:
tests/valid/easy_nondet_test.m:
tests/valid/error.m:
tests/valid/func_class.m:
tests/valid/func_int_bug_main.m:
tests/valid/higher_order.m:
tests/valid/higher_order2.m:
tests/valid/implied_mode.m:
tests/valid/indexing.m:
tests/valid/multidet_test.m:
tests/valid/nasty_func_test.m:
tests/valid/semidet_disj.m:
tests/valid/stack_alloc.m:
tests/valid/switches.m:
    Add missing section markers to these modules. They used to follow
    the `:- module' declaration directly with code.
2015-07-21 04:06:52 +10:00
Zoltan Somogyi
89628ae791 More speedups of inst handling code.
On tools/speedtest -l -m, my tests show a speedup of about 2%, but
on Dirk's stress test module, for which the compiler (used to) spend
almost all its time handling insts, the speedup is about 40%.

This diff also contains some small incidental changes I stumbled upon
the "need" for while working on the main change.

compiler/prog_data.m:
    The existing inst_test_results type used to be able to hold the results
    of four tests about a bound inst. Add two more: the set of inst vars that
    may occur in the inst, and whether a type constructor has already been
    propagated into the cons_ids of the bound insts.

    Put the fields of the the unify_inst and merge_inst inst_names into
    a more sensible order.

    Define types that hold the information stored in specific kinds of
    inst_names, for use by hlds_data.m (see below).

compiler/inst_user.m:
    For each user defined bound inst that matches exactly one parameterless
    type, propagate its type constructor into it, and record the fact that
    it has been done. This avoids having to do it many times later.
    Also record the set of inst vars in each inst, again to avoid having
    to repeat the test many times later.

compiler/mercury_compile_front_end.m:
    Invoke the inst_user module as soon after inst_check.m as we can.

compiler/hlds_data.m:
    Make the structure of six subtables of the inst table private, to allow
    them to be experimented with (and possibly changed) without code changes
    being required in other modules.

    The unify_inst_table, the ground_inst_table and the any_inst_table
    used to be maps whose keys were inst_names, but they were each only ever
    used with one kind of inst_name. Change their keys to the new types
    unify_inst_info, ground_inst_info and any_inst_info, which each contain
    the information in the unify_inst, ground_inst and any_inst inst_names
    respectively. That way, the searches in the maps will perform comparisons
    that don't need to switch on what kind of inst_name they are dealing with,
    and instead go directly to comparing the arguments.

    With the unify_inst_table, also go a step further. The unify_inst_info
    has two fields that are equivalent to booleans. Comparing these
    at every level of the map is wasteful, so switch the representation
    of the unify_inst_table from one map to four maps, one map for each
    possible combination of those booleans. This way, the two booleans
    in the unify_inst_info key are tested just once, when the applicable map
    is selected.

    The merge_inst_table used to have a pair of insts as keys. Replace that
    with the merge_inst_info type, which also holds a pair of insts,
    but on which comparisons should be a bit faster, since it is not
    polymorphic, and thus does not need an implicit typeinfo passed along.

    Provide a combined search_insert operation on each of the inst_tables,
    since their pattern of use is exactly that: search the table, and if
    the key is not found, insert a marker that says the entry is being
    worked on. This avoid one traversal of a possibly-large tree, with
    its associated (possibly very expensive) comparisons.

    For each inst table, provide conversion predicates to and from
    sorted association lists, for use by equiv_type_hlds.m

compiler/equiv_type_hlds.m:
    Expand equivalence types in the new structure of the inst tables.

compiler/inst_util.m:
    Use the new search_insert predicates for the various inst_tables.

    If one of the two insts being unified is free, then avoid using
    the unify_inst_table, since just doing the abstract unification
    is faster, and does not pollute the unify_inst_table.

    If both insts being merged are bound insts, then avoid using the
    merge_inst_table, since (a) the lookup is slower than just doing
    the merge, and (b) it can pollute the merge_inst_table to the extent
    that *all other lookups* in it become very slow.

compiler/inst_match.m:
    Use test result information in bound insts to speed up the corresponding
    tests.

compiler/set_of_var.m:
    Change the representation of sets of vars back to sparse_bitsets.
    I changed them to tree_bitsets several years ago to avoid some bad
    worst-case behavior with sparse_bitsets (which occurred when repeatedly
    appending to the "ends" of sets), but other algorithmic changes have
    since avoiding using set_of_vars in ways that induce that behavior,
    and now my benchmarking tells me that the bottleneck operation is
    conversion of set_of_vars to lists of vars. This is faster with
    sparse_bitsets, since unlike tree_bitsets, they don't have to unravel
    a tree structure.

compiler/mode_util.m:
    Export a predicate now needed by inst_user.m, and clean up the code a bit,
    factoring out repeated code.

compiler/modecheck_util.m:
    Modify an equality comparison of two insts to compare the instantiation
    states themselves, but NOT the test results about those instantiation
    states, since these can differ if the two insts have different histories.

compiler/hlds_code_util.m:
compiler/hlds_out_mode.m:
compiler/hlds_out_module.m:
compiler/mercury_to_mercury.m:
compiler/module_qual.m:
compiler/polymorphism.m:
compiler/prog_mode.m:
compiler/recompilation.usage.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.

The following changes are mostly incidental.

compiler/hlds_args.m:
    Speed up a predicate by avoiding the materialization of a list
    that is needed only for a test.

compiler/instmap.m:
    Clarify some code.

compiler/liveness.m:
    Avoid computing some value when it is not needed.

compiler/mode_errors.m:
    Avoid referring to "arguments" (plural) for errors involving *one*
    argument.

compiler/mode_info.m:
    Move the documentation of some predicates to their declarations.

compiler/modecheck_unify.m:
    Compute some data closer to where it is needed, to reduce the number
    of stack slots needed.

tests/invalid/constrained_poly_insts2.err_exp:
    Expect the updated error message from mode_errors.m (with "argument"
    in singular), as well as module qualified insts, since having inst_user.m
    push type_ctors into the definitions of named inst module qualifies
    the bound_insts inside those definitions.
2015-03-05 20:01:00 +11:00
Zoltan Somogyi
32008490e7 Speed up the compiler, and improve error messages for bad insts.
On tools/speedtest -l, my three tests shows speedups between 7% and 12%
for this diff. For Dirk's stress test module, for which the compiler
spends almost all its time handling insts, the speedup was bigger:
the compilation time went from 3.6 to 2.3 seconds.

compiler/inst_user.m:
    A new module that pretests user defined bound insts, and records
    the results in the insts themselves, so that those tests won't
    have to be done repeatedly, each time the compiler needs their results.

compiler/check_hlds.m:
compiler/notes/compiler_design.html:
    Include the new module.

compiler/mercury_compile_front_end.m:
    Invoke the new module.

compiler/inst_check.m:
    Rewrite this module to record, for each user defined bound inst, the type
    constructor(s) that the top-level bound insts match. This should allow a
    later diff to make inst_user.m more effective by pre-pushing the one
    matching type constructor into the inst, for insts that *do* have exactly
    *one* matching type constructor.

    The information needed for this also allows us to generate more precise
    error messages, fulfilling an earlier TODO.

compiler/hlds_data.m:
    Add a field to inst definitions to allow this recording.

    Don't hide the representation of the table of user insts. It just makes
    code working with it harder, and provides no benefit, since any useful
    structure imposed on top of the current simple map would require the
    lookups to be done *inside* the abstraction barrier, which the current
    design does not allow.

compiler/prog_data.m:
    Add a redundant field to the representation of data constructors (function
    symbols) in type definitions. This field holds the number of arguments
    of the function symbols, computed just once when the representation is
    created, rather than many times later on in many parts of the compiler.

compiler/prog_io_type_defn.m:
    Fill in the new redundant field when the constructor representations
    are created.

compiler/mode_util.m:
    Avoid the use of higher order code in a predicate that happens to be
    performance critical when compiling Dirk's stress test module.

compiler/add_mode.m:
compiler/add_type.m:
compiler/check_typeclass.m:
compiler/du_type_layout.m:
compiler/equiv_type.m:
compiler/export.m:
compiler/hhf.m:
compiler/hlds_module.m:
compiler/hlds_out_module.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/make_tags.m:
compiler/mercury_to_mercury.m:
compiler/ml_type_gen.m:
compiler/module_qual.m:
compiler/post_typecheck.m:
compiler/prog_type.m:
compiler/recompilation.check.m:
compiler/recompilation.usage.m:
compiler/special_pred.m:
compiler/term_constr_build.m:
compiler/term_norm.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/unify_proc.m:
compiler/unused_imports.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
    Conform to the changes above.

library/Mercury.options:
    Disable the trace flag that calls for the runtime testing of the invariants
    of the tree_bitset.m module. We have tested it far more than necessary,
    and it has been just overhead for a long time now. This helps speed up
    quantification, which takes nontrivial time on Dirk's module.

library/multi_map.m:
    Add a utility predicate needed above. It is a reverse set, i.e. a set
    with a value, key argument order.

    Put the code for the function versions of predicates next to the code
    for the predicate versions.

tests/warnings/inst_with_no_type.m:
tests/valid/inst_perf_bug_1.m:
    Fix indentation.

tests/warnings/inst_with_no_type.exp:
    Update this file to expect the new and improved error messages now
    generated by inst_check.m.
2015-02-28 14:40:34 +11:00
Zoltan Somogyi
11f2a2e9ee Print better contexts for module qualification errors.
Specifically, when we find undefined types in type definitions, say WHERE
the undefined type is (both as line number and as function symbol/arg number,
and field name if present), since the body of the type definition is sometimes
quite big.

compiler/module_qual.m:
    When module qualification found an error, it used to get the context
    it printed for the error from the mq_info structure, which also contained
    the rest of the state of the qualification process. The drawback of this
    setup is that the mq_info's record of the error context was updated
    only in a few of the places where that context actually changed.

    This diff takes the error context out of the mq_info, and passes it
    as a separate argument to the predicates that need it. This makes it
    really visible if a context is passed onward unchanged even when it
    should be updated.

    Fix some of these places, and mark the rest with XXXs.

    When printing error messages about predicate or function declarations,
    the message talked about definitions, not declarations. Fix that.

    Put a prog_context inside each function symbol of mq_error_context;
    don't require the creation of a separate memory cell for a pair
    to link the mq_error_context with the prog_context.

    Factor out some common code.

compiler/prog_data.m:
    I tried to put a context inside constraints for use in error contexts
    in module_qual.m, but that turned out to be a bad idea. Document why.

compiler/add_class.m:
compiler/equiv_type.m:
compiler/goal_util.m:
compiler/higher_order.m:
compiler/hlds_data.m:
compiler/post_typecheck.m:
compiler/pred_table.m:
compiler/prog_io_typeclass.m:
compiler/prog_type.m:
compiler/recompilation.usage.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/typeclasses.m:
compiler/unused_imports.m:
compiler/write_module_interface_files.m:
compiler/xml_documentation.m:
    Clean up some code dealing with constraints. I did this cleanup while
    adding contexts to constraints, a change I then had to undo.

tests/invalid/builtin_int.err_exp:
tests/invalid/errors.err_exp:
tests/invalid/errors1.err_exp:
tests/invalid/fundeps_vars.err_exp:
tests/invalid/missing_interface_import.err_exp:
tests/invalid/missing_interface_import2.err_exp:
tests/invalid/test_nested.err_exp:
tests/invalid/transitive_import.err_exp:
tests/invalid/undef_type.err_exp:
tests/invalid/undef_type_mod_qual.err_exp:
tests/recompilation/add_type_re.err_exp.2:
tests/recompilation/remove_type_re.err_exp.2:
    Update these expected output files to match the better messages
    we now generate.
2015-01-01 15:19:56 +11:00
Zoltan Somogyi
efb56544ed Speed up pred_info's setter predicates a bit.
compiler/hlds_pred.m:
    If the new value of a field of pred_info is likely to be bit-identical
    to the old value, then test the old and new bits for equality in the
    setter, and if they are the same, do not allocate a new pred_info
    structure that is guaranteed to be the same as the old one.

    By avoiding unnecessary memory turnover, this speeds up the compiler a bit,
    though I cannot nail down by how much. I measured it several times, with
    the results being no change, a speedup of 1%, and a speedup of 2%.

    Remove the unused setter predicate for the attributes field.

    Rename some access predicates to pred_infos to better reflect what they do.

    Add a distinguishing prefix to the fields of pred_infos.

compiler/*.m:
    Conform to the changes above.
2014-12-14 10:32:27 +11:00
Zoltan Somogyi
cbc6268c67 Print precise contexts for duplicate field names.
compiler/add_type.m:
    Record the context of the field name, not the context of the data
    constructor as a whole. The more fields a constructor has, and the
    more extensive comments they each have, the more misleading the
    overall context will be. (The code that uses these contexts does not
    need changing.)

compiler/prog_data.m:
    To store the information that add_type.m needs, create a space for
    the context of each field name next to the name itself. This requires
    breaking an old type equivalence; most of the "conform" changes below
    result from this.

compiler/prog_io_type_defn.m:
    When parsing type definitions, record the context of each field name
    in the new space.

compiler/field_access.m:
compiler/hlds_data.m:
compiler/hlds_pred.m:
compiler/make_hlds_passes.m:
compiler/mercury_to_mercury.m:
compiler/ml_code_util.m:
compiler/prog_type.m:
compiler/recompilation.check.m:
compiler/type_ctor_info.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/xml_documentation.m:
    Conform to the changes above.

compiler/post_typecheck.m:
    Conform to the changes above.

    Move some code out of a loop.

    Give a predicate a more meaningful name.

tests/invalid/repeated_field_name.{m,err_exp}:
    A new test case for this change, which defines a field named f2
    three times. Before this change, the compiler reported:

    repeated_field_name.m:008: Error: field `repeated_field_name.f2' multiply
    repeated_field_name.m:008:   defined.
    repeated_field_name.m:008:   Here is the previous definition of field
    repeated_field_name.m:008:   `repeated_field_name.f2'.

    which is a bit baffling. We now report

    repeated_field_name.m:011: Error: field `repeated_field_name.f2' multiply
    repeated_field_name.m:011:   defined.
    repeated_field_name.m:010:   Here is the previous definition of field
    repeated_field_name.m:010:   `repeated_field_name.f2'.
    repeated_field_name.m:012: Error: field `repeated_field_name.f2' multiply
    repeated_field_name.m:012:   defined.
    repeated_field_name.m:010:   Here is the previous definition of field
    repeated_field_name.m:010:   `repeated_field_name.f2'.

    which gives the correct contexts, and also reports BOTH duplicates.
    (Previously, we generated two identical error messages, but then sorting
    the list of errors removed one of them.)

tests/invalid/Mmakefile:
    Enable the new test case.
2014-10-24 02:39:48 +11:00