Commit Graph

149 Commits

Author SHA1 Message Date
Zoltan Somogyi
b6178ef723 Delete prog_out.m, moving its code to other modules.
compiler/parse_tree_out_cons_id.m:
    Move the predicates and functions in prog_out.m that deal with cons_ids
    to this module.

compiler/parse_tree_out_sym_name.m:
    Move the predicates and functions in prog_out.m that deal with sym_names
    and similar entities to this module.

compiler/parse_tree_out_type.m:
    Move the predicates and functions in prog_out.m that deal with types
    to this module.

compiler/parse_tree_out_misc.m:
    Move the predicates and functions in prog_out.m that deal with simple
    types to this module.

    Delete mercury_output_det and mercury_format_det, replacing all their
    uses with calls to mercury_det_to_string.

compiler/prog_out.m:
    Delete this module.

compiler/parse_tree.m:
    Delete prog_out from the parse_tree package.

compiler/Mercury.options:
compiler/notes/compiler_design.html:
    Delete references to prog_out.m.

compiler/*.m:
    Update imports and any explicit module qualifications to account
    for the moved code.

tools/filter_sort_imports:
    Automatically filter out any repeated imports. This can help with
    changes like this that redistribute the contents of one module to other
    modules. In this case, after a global replacement of prog_out's import
    with the import of parse_tree_out_misc, this updated script could
    remove this changed import from modules that already imported
    parse_tree_out_misc.
2023-04-09 16:23:13 +10:00
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
0f75764e41 Pinpoint more actual/expected type differences.
compiler/typecheck_errors.m:
    When there is a difference between actual and expected types
    in predicate calls, do not just print the actual and expected types,
    but if possible, point out the specific part(s) that cause the difference.
    For example, report differences in arities, purity, determinism etc.
    Also point out cases where the code is trying to specify the value
    of an existentially quantified type variable.

    When higher order types are printed as part of an error message,
    strip any builtin qualifiers not just from the names of types,
    but also from the names of the argument modes.

    Start each part of an actual/expected pair at the same level of
    indentation.

compiler/error_util.m:
    Add a way to print out small integers as english names (one, two etc)
    instead as numerals (1, 2 etc).

    Add a way to print out purity descriptions.

    Add a component, treat_next_as_first, that specifies that the next
    format_component should be treated as the first part of a sentence
    with respect to (de)capitalization by lower_next_if_not_first,
    even if it is preceded by other format_components in a message.
    This is useful in cases where the code that generates part of an
    error message does not know whether that part will end up at the start
    of the sentence, as the

        <preceding sentence, ending in a period>
        treat_next_as_first <context> lower_next_if_not_first, Words ...

    sequence will keep Words capitalized if <context> is empty,
    but will decapitalize it if <context> is not empty.

    Rename {qual,unqual}_pf_sym_name_orig_arity as
    {qual,unqual}_pf_sym_name_pred_form_arity, since this is clearer.

compiler/prog_out.m:
    Apply the same s/orig_arity/pred_form_arity/ rename to some functions.

compiler/module_qual.qual_errors.m:
    Fix an unrelated problem I came across while working on the changes above:
    stray spaces at the ends of words(...) format_components, which screwed up
    some error messages.

    Simplify the description of classes and predicates by using facilities
    in error_util.m that did not yet exist when this code was converted
    to use error_util.m.

compiler/prog_type.m:
    When stripping builtin qualifiers from types, strip them from the
    modes stored in the higher_order inst into of higher order types as well,
    for the same reason: to eliminate clutter in error messages.

    Make the strip_kind_annotation function return a value that
    shows in its type that the result will *not* be a kinded_type.
    THIS IS THE FIRST USE OF SUBTYPES IN THE COMPILER.

compiler/type_assign.m:
    Fix a long-standing documentation problem.

    The type_assign type has long had a field named ta_external_type_params,
    whose type was external_type_params, which was defined as equivalent
    to a list of type variables. The name does not say what kinds of type
    variables it contains, but the only two places that add type vars to
    this field add type vars that are existentially quantified, either
    by a predicate, or a cons_id. This diff therefore renames this field
    to ta_existq_tvars, and changes its type to be just plain list(tvar).
    (The external_type_params type has no documentation, so it may be used
    to store different kinds of type variables in different places,
    some of which may *not* be existentially quantified. Using the same name
    for different purposes may be confusing.)

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/check_promise.m:
compiler/check_typeclass.m:
compiler/convert_parse_tree.m:
compiler/hhf.m:
compiler/hlds_desc.m:
compiler/hlds_out_util.m:
compiler/make_hlds_error.m:
compiler/make_hlds_warn.m:
compiler/mark_tail_calls.m:
compiler/module_qual.qualify_items.m:
compiler/post_typecheck.m:
compiler/pred_table.m:
compiler/typecheck.m:
compiler/typecheck_debug.m:
compiler/typeclasses.m:
    Conform to the changes above.

tests/invalid/fbnf.{m,err_exp}:
    The motivating test case for this diff, slightly modified
    from the code posted to m-users.

tests/invalid/type_diff.{m,err_exp}:
    A test case to test the parts of the new code in typecheck_errors.m
    that are not covered by other tests.

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

tests/invalid/ext_type_bug.{m,err_exp}:
    Extend this test case to test the pinpointing of errors that try to bind
    existentially quantified type variables, at both the top level
    and nested inside other type constructors.

tests/invalid/bug197.err_exp:
tests/invalid/higher_order_mode_mismatch.err_exp:
tests/invalid_purity/impure_pred_t1_fixed.err_exp:
tests/invalid_purity/impure_pred_t2.err_exp:
tests/invalid_purity/purity_nonsense.err_exp:
tests/invalid_purity/purity_nonsense2.err_exp:
    Expect pinpointed type differences in these error messages.

tests/invalid/abstract_eqv.err_exp:
tests/invalid/integral_constant_no_suffix.err_exp:
tests/invalid/method_impl.err_exp:
tests/invalid/mixed_up_streams.err_exp:
tests/invalid/try_bad_params.err_exp:
tests/invalid/type_error_ambiguous.err_exp:
tests/invalid/types2.err_exp:
tests/invalid_nodepend/errors2.err_exp:
    Expected updated formatting in these error messages.
2022-10-11 22:59:03 +11:00
Zoltan Somogyi
f7355f708b Move var_db and var_{name,type}_source to var_db.m.
In the process, restrict the use of these types to just those modules
that need to provide services both other modules that use var_tables,
and modules that do not. The latter are modules that either can,
or always do, execute before var_tables are set up.

In some cases, code that previously operated on e.g. var_name_sources
had all its callers converted to use var_tables. In those cases, replace
the use of var_name_sources with var_tables directly.

In other cases, code that previously operated on e.g. var_name_sources
still has some callers that use varsets. In those cases,

- provide versions using var_tables if most callers use var_tables,
  renaming predicates/functions to make this the version seem the default,

- leave the operation to work on var_name_sources if some its callers
  also have only var_name_sources,

- if there are no such callers, keep just the two versions operating
  on varsets and var_tables respectively.

compiler/var_db.m:
compiler/var_table.m:
    Move the part of var_table.m that contains the definitions
    of the above three types, and the operations on them, to the
    new module var_db.m. Only 25 modules currently need var_db.m,
    compared to 176 for var_table.m.

compiler/parse_tree.m:
compiler/notes/compiler_design.html:
    Add and document the new module.

compiler/parse_tree_out_term.m:
    Add a "_vs" suffix to the names of operations that print variables
    or terms using varsets, and reuse their old names for versions
    that use var_table arguments. For the operations that need var_name_source
    versions, make it just select between the varset and var_table versions.

compiler/hlds_out_goal.m:
compiler/instmap.m:
compiler/hlds_out_mode.m:
compiler/hlds_out_util.m:
compiler/hlds_pred.m:
compiler/pd_info.m:
    Change some predicates that used to operate on var_{name,type}_sources
    to operate on var_tables.

    In hlds_out_mode.m, delete some unused predicates, and stop exporting
    a predicate whose only caller is local.

compiler/*.m:
    Conform to the changes above.
2022-08-19 10:44:39 +10:00
Zoltan Somogyi
2a1c2bb88a Make quantification using var_tables the default.
compiler/quantification.m:
    Add a "_vs" suffix to the names of predicates that use varsets, and
    delete the "_vt" suffix from the names of predicates that use var_tables.

    Keep private a predicate that now has no callers outside this module.

    Shorten the names of some function symbols.

compiler/recompute_instmap_deltas.m:
    Shorten the names of some function symbols.

compiler/equiv_type_hlds.m:
    Give a predicate a more meaningful name.

compiler/*.m:
    Conform to the change above.
2022-08-18 20:36:18 +10:00
Zoltan Somogyi
d787ee9355 Store var_tables in proc_infos.
This fixes the performance problem reported in Mantis bug #562.

compiler/hlds_pred.m:
    Instead of storing a varset and a vartypes in each proc_info,
    store just a var_table. Update the predicates that create
    or clone procedures accordingly.

    Where we had operations on proc_infos that had two versions,
    one operating on a varset/vartypes pair and one operating on var_table,
    keep only the latter, with the (shorter) name of the former.

    Delete the arity argument of proc_info_init, because the only
    valid value of that argument is the length of the list of the
    argument types. (In other words, this arg has been redundant
    all along.)

    Change the operations that create new variables in a procedure
    to get the caller to specify the (base) name of the new variable
    up front.

    Delete the unused predicate proc_info_ensure_unique_names.

compiler/type_util.m:
    Due to the change above, we now construct var_tables during the
    construction of the HLDS. The code that does that needs to fill in
    the field that says whether the type of each variable in the table
    is a dummy type or not. However, at this time, the pass that decides
    type representations has not been run yet. The code of is_type_a_dummy
    used to throw an exception in such situations.

    Change this so that in such situations, is_type_a_dummy returns
    a placeholder, not-guaranteed-to-be-correct value. Document why
    this is ok.

compiler/post_typecheck.m:
    Replace the placeholder values in vte_is_dummy fields in all
    the entries in the var_tables in all (valid) predicates with valid data.
    (If there are any invalid predicates, the compilation will fail anyway.)
    The clause_to_proc pass will copy these updated var_tables
    to be the initial var_tables in procedures.

compiler/make_goal.m:
    Change the operations that create new variables in a procedure
    to get the caller to specify the (base) name of the new variable
    up front. This is simpler than the old method, which created new
    variables without a name, and had the caller give them a name as
    a separate operation. And since var_tables need this info,
    get the caller to also specify whether the type is a dummy,
    if the type is not a builtin type which is known not to be a dummy.

compiler/var_table.m:
    Document the times when the types and is_dummy fields in var_table
    entries become meaningful.

    Fix a potential bug: when performing type substitutions in
    var_table entries, updating a variable's type may change whether
    that variable is a dummy or not, so recompute that info.
    It is quite possible that we *never* replace a nondummy type
    with a dummy type or vice versa, but in the absence of a convincing
    correctness argument for that proposition, better safe than sorry.

    Export the previously-private predicate transform_var_table
    to post_typecheck.

    Add code to implement the unused predicate deleted from hlds_pred.m:
    at the time I wrote it, I haven't yet realised that it was unused.
    The code I wrote here is therefore unused as well, so it is commented out.
    I did not delete it, because it may be useful later on.

compiler/direct_arg_in_out.m:
    Don't make and split var_tables, since it is no longer needed.

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_clause.m:
compiler/add_heap_ops.m:
compiler/add_pred.m:
compiler/add_special_pred.m:
compiler/add_trail_ops.m:
compiler/arg_info.m:
compiler/build_mode_constraints.m:
compiler/bytecode_gen.m:
compiler/check_typeclass.m:
compiler/clause_to_proc.m:
compiler/closure_analysis.m:
compiler/code_gen.m:
compiler/code_loc_dep.m:
compiler/complexity.m:
compiler/continuation_info.m:
compiler/cse_detection.m:
compiler/ctgc.livedata.m:
compiler/deep_profiling.m:
compiler/default_func_mode.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/distance_granularity.m:
compiler/equiv_type_hlds.m:
compiler/exception_analysis.m:
compiler/float_regs.m:
compiler/follow_code.m:
compiler/goal_mode.m:
compiler/goal_path.m:
compiler/higher_order.m:
compiler/hlds_out_pred.m:
compiler/hlds_rtti.m:
compiler/hlds_statistics.m:
compiler/inlining.m:
compiler/intermod.m:
compiler/intermod_analysis.m:
compiler/introduce_exists_casts.m:
compiler/introduce_parallelism.m:
compiler/lambda.m:
compiler/lco.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/loop_inv.m:
compiler/mark_tail_calls.m:
compiler/ml_accurate_gc.m:
compiler/ml_args_util.m:
compiler/ml_closure_gen.m:
compiler/ml_gen_info.m:
compiler/ml_proc_gen.m:
compiler/mode_errors.m:
compiler/mode_info.m:
compiler/modecheck_goal.m:
compiler/par_loop_control.m:
compiler/pd_debug.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/polymorphism_info.m:
compiler/post_typecheck.m:
compiler/proc_gen.m:
compiler/proc_requests.m:
compiler/purity.m:
compiler/push_goals_together.m:
compiler/quantification.m:
compiler/rbmm.add_rbmm_goal_infos.m:
compiler/rbmm.live_variable_analysis.m:
compiler/rbmm.points_to_analysis.m:
compiler/rbmm.points_to_graph.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_liveness_info.m:
compiler/rbmm.region_transformation.m:
compiler/recompute_instmap_deltas.m:
compiler/saved_vars.m:
compiler/simplify_goal_unify.m:
compiler/simplify_info.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/stack_opt.m:
compiler/stm_expand.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.domain.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_reuse.versions.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/switch_detection.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_initial.m:
compiler/term_errors.m:
compiler/term_pass1.m:
compiler/term_pass2.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
    Conform to the changes above. Mostly this means

    - not passing a module_info to get a var_table out of a proc_info, but
    - having to pass a module_info to code that either constructs a var_table,
      or adds entries to a var_table (since we now need the type table
      to figure out whether variables' types are dummies).
2022-08-18 18:53:15 +10:00
Zoltan Somogyi
9ba0dca846 Describe pred_origins separarely for users & devs.
compiler/pred_name.m:
    Replace pred_info_id_to_string, which was intended to generate ids
    of predicates for both users and developers, with two predicates,
    pred_origin_to_{user,dev}_string, that each target only one audience.
    The version for developers includes all the details that compiler
    developers may need, while the version for users does not, since
    it is just useless clutter from their point view.

    The new versions also take only a pred_origin as input, not the whole
    pred_info containing the pred_origin. This is needed, because for
    the base predicate whose transformation a pred_origin may record,
    we have *only* its pred_origin, not its pred_info.

    Record more information for some pred_origins. Record the promise type
    for predicates created for assertions (which we can longer look up
    in the pred_info). And record the file name and line number of
    initialise and finalise declarations, since a development wouldn't like
    being told "this is a predicate that implements an initialise declaration"
    if the module contained more than one, and the difference actually
    mattered.

    Switch from record pred_form arities to user arities for the pred_origins
    of tabling aux predicates, for consistency with other pred_origins.

compiler/hlds_out_util.m:
    Make the corresponding changes to the functions that used to call
    pred_info_id_to_string.

    Use pred_origin_to_dev_string to identify procedures that some cons_ids
    can refer to, since those cons_ids can appear only in compiler-generated
    code, which is of interest only to developers.

compiler/prog_item.m:
    Switch from record pred_form arities to user arities for the parse_tree
    version of pred_origins of tabling aux predicates.

compiler/prog_out.m:
    Provide versions of some functions that do not put quotes around
    the sym_names when converting them to strings. The
    pred_origin_to_dev_string does not want quotes, because our use of
    unmatched quotes `' can screw up syntax highlighting in HLDS dumps.

compiler/accumulator.m:
compiler/add_clause.m:
compiler/add_pragma_tabling.m:
compiler/add_pred.m:
compiler/cse_detection.m:
compiler/dead_proc_elim.m:
compiler/deep_profiling.m:
compiler/det_analysis.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/implementation_defined_literals.m:
compiler/make_hlds_passes.m:
compiler/mercury_compile_llds_back_end.m:
compiler/mode_errors.m:
compiler/modes.m:
compiler/par_conj_gen.m:
compiler/passes_aux.m:
compiler/pd_debug.m:
compiler/proc_gen.m:
compiler/purity.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.domain.m:
compiler/structure_reuse.indirect.m:
compiler/structure_sharing.analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_data.m:
compiler/term_constr_fixpoint.m:
compiler/term_constr_pass2.m:
compiler/term_constr_util.m:
compiler/tupling.m:
compiler/unused_args.m:
    Conform to the changes above.
2022-07-25 13:54:38 +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
8122e83d2a Record typechecking results in var_tables.
compiler/hlds_clauses.m:
    The clauses_info type used to have two fields whose type is "vartypes".
    One contained type information we knew before typechecking, e.g. from
    explicit "Var : type" annotations, while the other contained the
    *results* of typechecking. Keep the former, but replace the latter
    with a var_table.

    Allow compiler passes that construct clauses to fill in the first field
    with the types of the head variables, because for the clauses of some
    kinds of predicates (such as predicates implementing builtins) that are
    "constructed correct" and do not need typechecking, this is all we need.

    Put the fields of clauses_info that deal with variables and their types
    next to each other, in the order in which they are filled in.

compiler/add_clause.m:
    Don't construct the context pieces needed for parsing mode annotations
    on arguments in the clause head unless the clause head's arguments
    *have* mode annotations, which they virtually never do.

compiler/add_pred.m:
compiler/add_special_pred.m:
    Put the types of the head variables into the var_table in the clauses_info
    we create for clauses for builtin predicates and unify/compare/index
    predicates respectively, for use by unused_imports.m.

compiler/typecheck.m:
    Fill in the var_table field in

    - predicates we have typechecked,
    - predicates for which we have created stub clauses that are
      "born type-correct", and
    - predicates for class methods whose code will be created later,
      during the polymorphism pass.

    In the last case, we fill in only the types of the head variables,
    preserving old behavior.

    Give some predicates more meaningful names. Inline a predicate at its
    only call site.

compiler/post_typecheck.m:
    Switch to using the var_tables computed by typechecking.

    Reset varsets in clauses_infos to empty, to tell hlds_out_pred.m
    not use it as the source of variable name info.

compiler/hlds_pred.m:
    Provide functionality to record the types of head variables
    in both vartypes and in var_tables.

compiler/hlds_out_pred.m:
    Get information about variable names from either the clauses_info's
    varset field (if the varset is nonempty, not yet having been reset
    by post_typecheck.m), or from its var_table field (if the varset
    *has* been reset to empty).

    Likewise, get information about variable types from either the
    clauses_info's var_table field (if it is not empty, having been filled in
    either by typechecking or by code created the type clauses "type-correct"
    at the start), or from its explicit_vartypes field (if the var_table field
    has not yet been filled in).

    It is possible that in the future, we may want to dump out the
    contents of the explicit_vartypes field even if the var_table
    has also been filled in. However, since the old code of write_pred
    had no such functionality, the chance we will need that in the future
    is small, and we can deal with it when the issue does arise.

compiler/goal_path.m:
compiler/hlds_out_goal.m:
compiler/intermod.m:
compiler/unify_proc.m:
    Convert these modules to use var_tables.

compiler/prog_type.m:
compiler/type_util.m:
    Record the fact that the builtin type "store_at_ref_type" is not a dummy
    type. Without this special-casing, the creation of a var_table containing
    a variable of this type would crash the compiler, because

    - unlike other builtin types, this one *has* a definition, in
      private_builtin.m, but
    - since it is a builtin type, its "definition" in the type table
      has no representation information, so the code of is_type_a_dummy
      cannot tell if that "definition" is a dummy or not.

compiler/prog_util.m:
    Provide the var_table equivalent of an existing utility predicate
    for varsets.

compiler/qual_info.m:
    Give a field of the qual_info type a more meaningful name.

compiler/typecheck_errors.m:
    Fix argument order and variable names.

compiler/vartypes.m:
compiler/var_table.m:
    Add a predicate to check whether a variable has a user-given name.

    Replace the varset_vartypes type in vartypes.m with the type_qual type
    in var_table.m, which uses var_tables, since its user, hlds_out_goal.m,
    has been converted to use var_tables. (Most variables of this type
    have been named TypeQual, which is why the type now has that name.)

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

    Export the definition of the inst_graph_info type, instead of exporting
    a getter and a setter for every one of its fields.

compiler/higher_order.m:
    Conform to the changes above, by calling clauses_info_init,
    instead of repeating its code here.

compiler/accumulator.m:
compiler/add_foreign_proc.m:
compiler/add_pragma_type_spec.m:
compiler/build_mode_constraints.m:
compiler/check_promise.m:
compiler/clause_to_proc.m:
compiler/format_call.m:
compiler/hhf.m:
compiler/instance_method_clauses.m:
compiler/lambda.m:
compiler/mode_constraints.m:
compiler/old_type_constraints.m:
compiler/par_loop_control.m:
compiler/polymorphism.m:
compiler/polymorphism_info.m:
compiler/prop_mode_constraints.m:
compiler/purity.m:
compiler/stm_expand.m:
compiler/structure_reuse.versions.m:
compiler/table_gen.m:
    Conform to the changes above.

tests/invalid/illtyped_compare.err_exp:
    Expect an improved variable name from unify_proc.m.

tests/invalid/try_detism.err_exp:
    Expect a different variable number for an unnamed variable.
2022-05-29 15:22:16 +10:00
Zoltan Somogyi
b96a90f948 Parse disjunctions using tail recursive code ...
to allow even very long disjunctions to be parsed in constant stack space.
This fixes Mantis bug #559.

compiler/prog_item.m:
    We used to represent a disjunction like ( GoalA ; GoalB ; GoalC ; GoalD )
    in the parse tree as

        disj_expr(ContextA, GoalA,
            disj_expr(ContextB, GoalB,
                disj_expr(ContextC, GoalC,
                    GoalD)))

    To enable the changes in parse_goal.m and parse_dcg_goal.m, switch over
    to representing them as

        disj_expr(ContextA, GoalA, GoalB, [GoalC, GoalD])

    The type of this term enforces the invariant that a disjunction
    must have at least two disjuncts.

    The fact that this throws away ContextB and ContextC is not a problem;
    they were never used, being thrown away when converting the parse tree
    to the HLDS.

compiler/parse_goal.m:
compiler/parse_dcg_goal.m:
    After seeing the first comma in the above disjunction, these parsers
    used to (1) parse its left operand, GoalA, (2) parse its right operand,
    ( GoalB ; GoalC ; GoalD), and then (3) check for errors. This code
    was prevented from being tail recursive both by the presence of step 3,
    and the fact that step 2 indirectly invokes another predicate that
    (until my previous change to parse_goal.m) had a different determinism.

    Fix the first issue by having the new predicate parse_goal_disjunction,
    and its DCG variant, accumulate errors *alongside* disjuncts,
    to be checked just once, at the end, outside the loop. Fix the second
    issue by having parse_goal_disjunction test whether the right operand
    of the semicolon has the form of a disjunction, and if it does,
    recursing on it directly. This makes parse_goal_disjunction
    self-tail-recursive, which should allow it to process disjunctions
    of arbtrary length using fixed stack space (in grades that support
    tail recursion, that is).

    Move the code to flatten disjunctions from goal_expr_to_goal.m to
    these modules, because it is simpler to get the right result this way
    in DCG clauses (for non-DCG clauses, it works simply either way).

compiler/goal_expr_to_goal.m:
    Convert the updated parse tree representation of disjunctions to HLDS,
    and don't flatten disjunctions here anymore.

compiler/parse_item.m:
    Add some infrastructure for debugging changes like this.

compiler/add_clause.m:
    Improve the infrastructure of debugging changes like this, by making it
    more selective.

    To make this possible, pass the predicate name to a predicate
    that did not need it before. Fix the argument order of that predicate.

compiler/make_hlds_warn.m:
    Don't flatten parse tree disjunctions, since the code constructing them
    has done it already.

compiler/get_dependencies.m:
compiler/module_qual.collect_mq_info.m:
compiler/parse_tree_out_clause.m:
compiler/prog_item_stats.m:
compiler/prog_util.m:
    Conform to the change in prog_item.m.

compiler/instance_method_clauses.m:
    Conform to the change in add_clause.m.

tests/hard_coded/flatten_disjunctions.{m,exp}:
    A new test case both testing and documenting the need for flattening
    disjunctions.

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

tests/invalid/require_switch_arms_detism.err_exp:
    Expect updated numbers for anonymous variables. This is due to
    goal_expr_to_goal.m now processing disjuncts in a different order
    than before.
2022-05-06 15:19:49 +10:00
Zoltan Somogyi
ea4f95a7ed Use var_tables in lco.m, and when dumping goals.
Since this is the first converted module that dumps out goals when
debugging trace flags are enabled, this required generalizing the code
that does that, to take either varsets or var_tables as a means of
specifying the names of variables. We do this via a new type,
var_name_source, which contains either a varset or a var_table.

Almost all of this diff is there to implement this generalization.
A large part of it affects code in the parse_tree package that we use
to write out the parts of HLDS goals that are defined by types defined
in that package. Since we want to avoid making any part of the parse_tree
package dependent on the hlds package, this required defining the
var_name_source type in the parse_tree package, which in turn requires
var_table.m to be in that same package.

compiler/lco.m:
    Convert this module to use var_tables instead of varsets and vartypes.

compiler/var_table.m:
    Move this module from the hlds package to the parse_tree package.

    To make this, possible, move the parts that required access to the HLDS
    to hlds_pred.m, from where it was usually invoked.

    Export some utility predicates to allow the moved code to work
    in hlds_pred.m without access to the actual definition of the
    var_table type.

    Define the var_name_source type.

    Add some utility functions for use by code writing out variable names.

compiler/hlds_pred.m:
    Add the code moved from var_table.m.

compiler/vartypes.m:
    Move this module from the hlds package to the parse_tree package,
    for symmetry with var_table.m. It did not depend on being in hlds
    in any way.

compiler/hlds.m:
compiler/parse_tree.m:
    Move vartypes.m and var_table.m from the hlds package
    to the parse_tree package.

compiler/hlds_out_goal.m:
    Change all the predicates in this module to take a var_name_source
    instead of a prog_varset.

    Fix some comments.

compiler/hlds_out_util.m:
    Change some of the predicates in this module (those called from
    hlds_out_goal.m) to take a var_name_source instead of a prog_varset.

compiler/parse_tree_out_term.m:
    Provide variants of some existing predicates and functions that take
    var_name_sources instead of varsets. The code of the copies
    duplicates the logic of the originals, though I hope that this
    duplication can be done away with at the end of the transition.
    (The best solution would be to use a typeclass with methods
    that convert vars to their names, but we would want to ensure
    that the compiler can specialize all the affected predicates
    and functions to the two instances of this typeclass, which is
    something that we cannot do yet. In the meantime, the lack of
    any generalization in the old versions preserves their performance.)

tools/sort_imports:
tools/filter_sort_imports:
    A new tool that automatically sorts any occurrences of consecutive
    ":- import_module" declarations in the named files. The sorting is done
    in filter_sort_imports; sort_imports loops over the named files.

    After automatically replacing all occurrences of hlds.{vartypes,var_table}
    in import_module declarations with their parse_tree versions, the updated
    import_module declarations were usually out of order with respect to
    their neighbours. I used this script to fix that, and some earlier
    out-of-order imports.

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_heap_ops.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_trail_ops.m:
compiler/analysis.m:
compiler/arg_info.m:
compiler/build_mode_constraints.m:
compiler/bytecode_gen.m:
compiler/call_gen.m:
compiler/check_promise.m:
compiler/closure_analysis.m:
compiler/closure_gen.m:
compiler/code_info.m:
compiler/code_loc_dep.m:
compiler/common.m:
compiler/compile_target_code.m:
compiler/complexity.m:
compiler/const_prop.m:
compiler/constraint.m:
compiler/continuation_info.m:
compiler/convert_parse_tree.m:
compiler/coverage_profiling.m:
compiler/cse_detection.m:
compiler/ctgc.datastruct.m:
compiler/ctgc.util.m:
compiler/dead_proc_elim.m:
compiler/deep_profiling.m:
compiler/deforest.m:
compiler/delay_construct.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/det_util.m:
compiler/direct_arg_in_out.m:
compiler/disj_gen.m:
compiler/distance_granularity.m:
compiler/equiv_type_hlds.m:
compiler/exception_analysis.m:
compiler/file_names.m:
compiler/float_regs.m:
compiler/follow_vars.m:
compiler/format_call.m:
compiler/generate_dep_d_files.m:
compiler/get_dependencies.m:
compiler/goal_expr_to_goal.m:
compiler/goal_mode.m:
compiler/goal_path.m:
compiler/goal_store.m:
compiler/goal_util.m:
compiler/granularity.m:
compiler/hhf.m:
compiler/higher_order.m:
compiler/hlds_clauses.m:
compiler/hlds_code_util.m:
compiler/hlds_error_util.m:
compiler/hlds_goal.m:
compiler/hlds_llds.m:
compiler/hlds_out_pred.m:
compiler/hlds_rtti.m:
compiler/hlds_statistics.m:
compiler/inlining.m:
compiler/inst_check.m:
compiler/inst_test.m:
compiler/inst_user.m:
compiler/instance_method_clauses.m:
compiler/instmap.m:
compiler/intermod.m:
compiler/intermod_analysis.m:
compiler/interval.m:
compiler/introduce_exists_casts.m:
compiler/introduce_parallelism.m:
compiler/item_util.m:
compiler/lambda.m:
compiler/live_vars.m:
compiler/liveness.m:
compiler/llds.m:
compiler/llds_out_data.m:
compiler/llds_out_file.m:
compiler/llds_out_util.m:
compiler/lookup_switch.m:
compiler/loop_inv.m:
compiler/make.module_target.m:
compiler/make.util.m:
compiler/make_goal.m:
compiler/make_hlds_separate_items.m:
compiler/make_hlds_types.m:
compiler/mark_tail_calls.m:
compiler/mercury_compile_mlds_back_end.m:
compiler/middle_rec.m:
compiler/ml_accurate_gc.m:
compiler/ml_args_util.m:
compiler/ml_call_gen.m:
compiler/ml_closure_gen.m:
compiler/ml_code_gen.m:
compiler/ml_code_util.m:
compiler/ml_commit_gen.m:
compiler/ml_disj_gen.m:
compiler/ml_foreign_proc_gen.m:
compiler/ml_gen_info.m:
compiler/ml_lookup_switch.m:
compiler/ml_proc_gen.m:
compiler/ml_simplify_switch.m:
compiler/ml_switch_gen.m:
compiler/ml_tag_switch.m:
compiler/ml_unify_gen.m:
compiler/ml_unify_gen_construct.m:
compiler/ml_unify_gen_deconstruct.m:
compiler/ml_unify_gen_test.m:
compiler/ml_unify_gen_util.m:
compiler/mlds_to_c_data.m:
compiler/mlds_to_c_func.m:
compiler/mlds_to_c_global.m:
compiler/mlds_to_cs_class.m:
compiler/mlds_to_cs_file.m:
compiler/mlds_to_java_data.m:
compiler/mlds_to_java_file.m:
compiler/mlds_to_java_stmt.m:
compiler/mlds_to_java_type.m:
compiler/mmc_analysis.m:
compiler/mode_comparison.m:
compiler/mode_constraints.m:
compiler/mode_debug.m:
compiler/mode_errors.m:
compiler/mode_info.m:
compiler/mode_ordering.m:
compiler/modecheck_call.m:
compiler/modecheck_coerce.m:
compiler/modecheck_goal.m:
compiler/modecheck_unify.m:
compiler/modecheck_util.m:
compiler/modes.m:
compiler/module_cmds.m:
compiler/old_type_constraints.m:
compiler/opt_debug.m:
compiler/optimize.m:
compiler/options_file.m:
compiler/ordering_mode_constraints.m:
compiler/par_loop_control.m:
compiler/parse_item.m:
compiler/parse_string_format.m:
compiler/parse_tree_out_inst.m:
compiler/parse_tree_to_term.m:
compiler/parse_util.m:
compiler/pd_debug.m:
compiler/pd_info.m:
compiler/pd_util.m:
compiler/peephole.m:
compiler/polymorphism.m:
compiler/polymorphism_info.m:
compiler/polymorphism_lambda.m:
compiler/polymorphism_type_class_info.m:
compiler/polymorphism_type_info.m:
compiler/post_typecheck.m:
compiler/pragma_c_gen.m:
compiler/pred_name.m:
compiler/pred_table.m:
compiler/prog_item.m:
compiler/prog_rep.m:
compiler/prop_mode_constraints.m:
compiler/purity.m:
compiler/push_goals_together.m:
compiler/qual_info.m:
compiler/quantification.m:
compiler/rbmm.execution_path.m:
compiler/rbmm.m:
compiler/rbmm.points_to_analysis.m:
compiler/rbmm.points_to_graph.m:
compiler/rbmm.points_to_info.m:
compiler/rbmm.region_resurrection_renaming.m:
compiler/rbmm.region_transformation.m:
compiler/recompilation.used_file.m:
compiler/recompilation.version.m:
compiler/recompute_instmap_deltas.m:
compiler/resolve_unify_functor.m:
compiler/rtti.m:
compiler/rtti_out.m:
compiler/rtti_to_mlds.m:
compiler/saved_vars.m:
compiler/set_of_var.m:
compiler/simplify_goal_call.m:
compiler/simplify_goal_conj.m:
compiler/simplify_goal_disj.m:
compiler/simplify_goal_ite.m:
compiler/simplify_goal_scope.m:
compiler/simplify_goal_switch.m:
compiler/simplify_goal_unify.m:
compiler/simplify_info.m:
compiler/simplify_proc.m:
compiler/size_prof.m:
compiler/smm_common.m:
compiler/ssdebug.m:
compiler/stack_alloc.m:
compiler/stack_layout.m:
compiler/stack_opt.m:
compiler/stm_expand.m:
compiler/store_alloc.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.choose_reuse.m:
compiler/structure_reuse.direct.detect_garbage.m:
compiler/structure_reuse.domain.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.lbu.m:
compiler/structure_reuse.lfu.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/superhomogeneous.m:
compiler/switch_detection.m:
compiler/switch_gen.m:
compiler/switch_util.m:
compiler/table_gen.m:
compiler/tabling_analysis.m:
compiler/term_constr_build.m:
compiler/term_constr_data.m:
compiler/term_constr_initial.m:
compiler/term_constr_main.m:
compiler/term_constr_main_types.m:
compiler/term_constr_util.m:
compiler/term_pass1.m:
compiler/term_traversal.m:
compiler/term_util.m:
compiler/trace_gen.m:
compiler/trailing_analysis.m:
compiler/transform_llds.m:
compiler/try_expand.m:
compiler/tupling.m:
compiler/type_assign.m:
compiler/type_ctor_info.m:
compiler/type_util.m:
compiler/typecheck.m:
compiler/typecheck_debug.m:
compiler/typecheck_errors.m:
compiler/typecheck_info.m:
compiler/unify_gen_construct.m:
compiler/unify_gen_deconstruct.m:
compiler/unify_proc.m:
compiler/unique_modes.m:
compiler/unneeded_code.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
compiler/var_locn.m:
compiler/write_deps_file.m:
compiler/write_module_interface_files.m:
    Conform to the changes above.
2022-04-18 02:00:38 +10:00
Zoltan Somogyi
0186a64520 Warn for unneeded use of mode-specific clauses.
compiler/add_clause.m:
    Generate a warning for mode-specific clauses when the clause is for
    a predicate that has only one mode, provided that the warning is enabled.

compiler/options.m:
    Add an option to enable this warning.

doc/user_guide.texi:
    Document this option.

library/exception.m:
library/int.m:
library/rtti_implementation.m:
library/string.m:
    Delete modes from clause heads that would get this warning.

tests/valid/spurious_purity_warning.m:
    Delete modes from clause heads that would get this warning.

    Do not interleave predicate definitions.

tests/warnings/unneeded_mode_specific_clause.{m,exp}:
    A test case for this warning.
tests/warnings/Mmakefile:
    Enable the new test case.

tests/invalid/multimode_syntax.err_exp:
    Expect the new warning.
2022-04-13 23:39:23 +10:00
Zoltan Somogyi
2a58b0ba4c Simplify the addition of promises to the HLDS.
compiler/make_hlds_passes.m:
    With non-promise predicates, we add the predicate declarations first,
    and the clauses second.

    With promises, we used to try to add the clauses first, have add_clause.m
    notice that the clause is for a predicate that has not been declared yet,
    add the implicit declaration of the predicate representing the promise,
    and then, finally, add the clause.

    Simplify this process by adding the predicate declaration for the promise
    to the HLDS before adding it clause.

    Give some variables better names.

compiler/add_pred.m:
    Export a previously internal predicate, to allow the promise-adding code
    in make_hlds_passes.m to call it. It used to be called by another predicate
    that add_pred.m exported, but it is simpler to inline that predicate
    at what was its only call site in make_hlds_passes.m.

    Give the predicates involved more descriptive names.

    Move here from add_clause.m the code to detect conflict between
    the names of user-defined predicates and predicates defined
    for promises in the compiler.

compiler/add_clause.m:
    Delete the code that used to treat promises specially with respect to
    implicit declarations.

    Avoid testing a condition twice.

compiler/add_foreign_proc.m:
compiler/add_pragma_tabling.m:
    Conform to the new predicate names exported by add_pred.m.
2022-04-02 20:36:19 +11:00
Zoltan Somogyi
92438b2ec6 Make make_hlds.m a package.
compiler/make_hlds.m:
    This module used to both

    - include several submodules, and
    - define several types and predicates.

    For some years now, we have preferred to do these two kinds of things
    in separate modules, with package modules containing *only* include_module
    declarations, and other modules containing *no* include_module
    declarations. The reason is that submodules of a package automatically
    get the imports of their parent, which creates unwanted coupling
    between the submodule and its parent. This problem vanishes if
    the parent module contains no imports, but the only practical way
    to sustain that over time is for the parent to define nothing.

    This diff therefore moves the definitions of types and predicates
    out of make_hlds.m. It moves the types to a new submodule,
    make_hlds_types.m. Since the predicates it defined were only
    forwarding predicates, they can be deleted without replacement,
    provided that the predicates they forwarded to are in *public*
    submodules of make_hlds.m. This diff therefore arranges that.
    It does the same with a forwarding type.

compiler/make_hlds_types.m:
    A new submodule of make_hlds.m that contains the type definitions
    that used to be in make_hlds.m itself.

compiler/instance_method_clauses.m:
    A new submodule of make_hlds.m that contains the parts of add_class.m
    that generate the clauses that define predicates that implement
    instance methods. This part of add_class.m was completely separate
    from the rest of add_class.m (it wasn't even invoked from there),
    so putting it in its own module eliminates unnecessary coupling.

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

compiler/add_class.m:
    Delete the code that has been moved to instance_method_clauses.m.

compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_mode.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma.m:
compiler/add_pred.m:
compiler/add_solver.m:
compiler/add_type.m:
compiler/check_typeclass.m:
compiler/goal_expr_to_goal.m:
compiler/make_hlds_passes.m:
compiler/make_hlds_warn.m:
compiler/mercury_compile_front_end.m:
compiler/mercury_compile_main.m:
compiler/qual_info.m:
compiler/state_var.m:
compiler/superhomogeneous.m:
    Conform to the changes above, mostly by adding explicit import_module
    declarations to replace a subset of the import_module declarations
    that these modules used to implicitly inherit from their parent.
2022-03-31 16:54:33 +11:00
Zoltan Somogyi
7424f93a30 Use one error msg for undeclared mode references.
compiler/add_clause.m:
compiler/make_hlds_passes.m:
    We used to have two separate predicates for generating error messages
    about references to undeclared modes of predicates and functions.
    One, in add_clause.m, was for undeclared modes in mode-specific clauses,
    and generated messages that were as informative as possible.
    The other, in make_hlds_passes.m, which was used for undeclared modes
    in type_spec in foreign_export pragmas, was perfunctory, and gave
    no details.

    Act on an old XXX and delete the second predicate, replacing its uses
    by calls to the first. To make this possible, move the first predicate,
    which used to be private to add_clause.m, to make_hlds_passes.m.

compiler/add_pragma.m:
compiler/add_pragma_type_spec.m:
    Call the first predicate, not the second.

compiler/prog_item.m:
    The first predicate requires access to a varset that describes the names
    of any inst variables in the undeclared mode. Include a varset for this
    purpose in foreign_export pragmas. (type_spec pragmas already had the
    required varset.)

compiler/convert_parse_tree.m:
compiler/get_dependencies.m:
compiler/item_util.m:
compiler/make_hlds_error.m:
compiler/module_qual.qualify_items.m:
compiler/parse_pragma_foreign.m:
compiler/parse_tree_out_pragma.m:
compiler/prog_mutable.m:
    Conform to the change in prog_item.m.

tests/invalid/pragma_qual_error.err_exp:
tests/invalid/type_spec.err_exp:
    Expect updated error messages.
2022-02-23 04:31:38 +11:00
Zoltan Somogyi
e657a091e4 Encode the arity kind in the type in pred lookups.
compiler/pred_table.m:
    Some predicates in this module have traditionally taken an arity argument
    that *included* function result arguments, while others took an arity
    arguments that *excluded* function result arguments. While the difference
    was documented, it was not enforced in the types. Change this by
    switching the two kinds of arities to pred_form_arities and user_arities
    respectively.

    Change the internal data structures to specify in the types
    that they operate on user_arities.

    Change the operation of lookup_builtin_pred_proc_id as part of the
    change to goal_util.m (described below).

compiler/goal_util.m:
    When looking up the pred_info of a builtin, callers used to pass to the
    predicates that did that (generate_simple_call and generate_foreign_proc)
    a list of the arguments of the call without specifying which arguments
    were type_info/typeclass_info arguments added by polymorphism.
    This meant that the length of the argument list was *not* necessarily
    the called predicate or function's pred form arity, but could exceed it
    by the number of arguments added by polymorphism. The only reason this
    worked was because the lookup_builtin_pred_proc_id procedure they used
    to look up the named predicate in the pred table compensated for it

    - by doing a lookup on the original arity plus one, if the lookup on the
      original arity failed, and

    - in all the calls to generate_simple_call and generate_foreign_proc,
      the number of arguments added by polymorphism was either zero or one.

    Nevertheless, the system was fragile. It could have broken either

    - because when looking up the arity that included a type_info argument,
      (e.g. one typeinfo and two original args) the lookup could have found
      a false match (a predicate with the same name with three original args),

    - or because a new call to a new builtin could need to specify two or more
      arguments added by polymorphism.

    Fix this issue by

    - requiring calls to generate_simple_call and generate_foreign_proc
      to pass the arguments added by polymorphism separately, so the number
      of the original arguments specifies the predicate's pred_form_arity, and

    - deleting the code in lookup_builtin_pred_proc_id that tried to
      compensate for the presence of an "unannounced" typeinfo argument.

compiler/analysis.m:
    Change the type of a slot in a structure from arity to pred_form_arity,
    since that seems to have been how that slot was used.

compiler/recompilation.check.m:
compiler/recompilation.m:
compiler/recompilation.usage.m:
    Conform to the changes above, but only in a minimal fashion,
    because I don't *know* whether the values of type 'arity' passed around
    in the recompilation modules represent user arities or pred form arities.
    Record my guesses, but also record the fact that they are *only* guesses.
    Mark suspect code with "XXX ARITY BUG".

compiler/add_heap_ops.m:
compiler/add_trail_ops.m:
compiler/stm_expand.m:
compiler/table_gen.m:
    Conform to the changes above.

    Rationalize the argument order of the internal module-specific predicates
    they use to generate calls to builtins.

compiler/add_class.m:
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/analysis.file.m:
compiler/check_typeclass.m:
compiler/complexity.m:
compiler/dead_proc_elim.m:
compiler/deep_profiling.m:
compiler/dep_par_conj.m:
compiler/direct_arg_in_out.m:
compiler/distance_granularity.m:
compiler/format_call.m:
compiler/goal_util.m:
compiler/granularity.m:
compiler/higher_order.m:
compiler/hlds_module.m:
compiler/intermod.m:
compiler/lco.m:
compiler/make_hlds_passes.m:
compiler/mmc_analysis.m:
compiler/modecheck_goal.m:
compiler/par_loop_control.m:
compiler/polymorphism_type_class_info.m:
compiler/polymorphism_type_info.m:
compiler/pred_table.m:
compiler/purity.m:
compiler/rbmm.region_transformation.m:
compiler/resolve_unify_functor.m:
compiler/simplify_goal_call.m:
compiler/simplify_goal_scope.m:
compiler/simplify_goal_unify.m:
compiler/size_prof.m:
compiler/special_pred.m:
compiler/ssdebug.m:
compiler/try_expand.m:
compiler/typecheck.m:
compiler/unify_proc.m:
    Conform to the changes above.
2022-02-22 23:59:20 +11:00
Zoltan Somogyi
ee0a21b98c Replace some 'arity's with {pred_form,user}_arity.
This removes uncertainty in the affected places in the compiler,
because unlike the 'arity' type, the pred_form_arity and user_arity
types specify *which definition* of arity they represent.

Whether I replaced a use of arity with pred_form_arity or user_arity
depended on whether I believed the original arity to have been intended to be
- a pred_form_arity without the wrapper, or
- a user_arity without the wrapper.
The reason for the size of this diff is that when I replaced one use of
arity with pred_form_arity or user_arity, I often could not be sure about
the right way to propagate this change to the rest of the affected code
without making similar replacements elsewhere, and seeing whether
*that* worked. This diff is in effect the "smallest fixpoint" of this process.

In places where the pred form arity of predicate or function
is inherent in a list which has one element for each argument
(the element may be a term, a type, a mode, etc), do not take
a separate arity argument as well, since (a) it is not needed, and
(b) it is a potential source of inconsistencies. The only downside
is that we may need to take the length of a list in both the caller
and the callee, but this cost is negligible.

Add "XXX ARITY" comments to mark opportunities for future improvements.

compiler/hlds_clauses.m:
    Make clauses_info_init take a pred_form_arity instead of an arity
    as argument.

compiler/hlds_pred.m:
    Make pred_info_init take a pred_form_arity instead of an arity
    as argument.

compiler/prog_data.m:
    Specify that the arity part of the pf_sym_name_arity type
    is a pred_form_arity.

    Add a variant of the sym_name_arity type, which does not say
    what kind of arity it contains, which does say that it contains
    a pred_form_arity.

    Store the arities of instance methods as user_arity, not arity.

    Move the definition of an instance method out of between
    the instance's name and its arity.

    Add a convenience function for computing the pred_form_arity
    of an argument list.

    Delete a type moved to parse_sym_name.m.

compiler/prog_item.m:
    Use user_arities in item_initialise_infos and item_finalise_infos.

compiler/typecheck_errors.m:
    Specify that the arity in an arg_vector_plain_pred_call,
    and in the argument list of a function that construct a message
    for a related type error, is a pred_form_arity.

compiler/add_class.m:
    In the predicate that converts clauses to instance methods,
    delete its arity argument, given that another argument is
    the list of argument terms.

    Move the generator of a variable before its first consumer.

compiler/add_clause.m:
    In predicates that add clauses to the HLDS, delete their arity argument
    where another argument is the list of argument terms.

compiler/superhomogeneous.m:
    Explicit specify that the arity of a clause is recorded as a
    pred_form_arity.

compiler/add_foreign_proc.m:
    In predicates that add foreign_procs to the HLDS, delete their arity
    argument where another argument is the list of argument terms.

compiler/check_typeclass.m:
    Record the arity of the method being checked as user_arity.

    Fix incorrect arities in the error messages we generate.

compiler/make_hlds_error.m:
    Get callers to specify the pred_form_arity of a missing predicate or
    function. If that predicate or function exists with other arities,
    we try to be helpful and print out those arities in the error message.
    This process had some bugs, which this diff fixes.

compiler/typecheck_info.m:
    Specify that the arity we record for overloaded symbols is the
    pred_form_arity.

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

    Move a comment to the code it is about.

compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
    Conform to the changes above.

    In two comments, write out the user arities of function methods,
    not their pred form arity.

compiler/make_hlds_passes.m:
    Conform to the change in the representation of initialise and finalise
    items.

    Use the new method for constructing target names in prog_foreign.m.

    Indent the code example part of an error message.

compiler/prog_foreign.m:
    Provide a single predicate for creating target language names
    for initialise and finalise predicates. This new predicate factors out
    what used to be duplicate code in make_hlds_passes.m.

compiler/parse_sym_name.m:
    Move a type here from prog_data.m, since it is used only by
    parse_sym_name.m and the modules that call it.

compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_special_pred.m:
compiler/check_promise.m:
compiler/det_report.m:
compiler/get_dependencies.m:
compiler/goal_expr_to_goal.m:
compiler/higher_order.m:
compiler/hlds_out_typeclass_table.m:
compiler/intermod.m:
compiler/mark_tail_calls.m:
compiler/parse_class.m:
compiler/parse_mutable.m:
compiler/parse_tree_out.m:
compiler/pred_name.m:
compiler/prog_mutable.m:
compiler/prog_out.m:
compiler/state_var.m:
compiler/table_gen.m:
compiler/typecheck.m:
compiler/unused_args.m:
    Conform to the changes above.

compiler/make_hlds.m:
    Conform to the change in add_class.m.

tests/invalid/bad_pred_arity.err_exp:
tests/invalid/mode_decl_in_wrong_section.err_exp:
tests/invalid/pragma_c_code_dup_var.err_exp:
tests/invalid/state_vars_test3.err_exp:
tests/invalid/typeclass_bogus_method.err_exp:
tests/invalid/typeclass_test_3.err_exp:
tests/invalid/typeclass_test_4.err_exp:
    Update these expected outputs for the bug fixes above.

tests/invalid_nodepend/bad_finalise_decl.err_exp:
tests/invalid_nodepend/bad_initialise_decl.err_exp:
    Update these expected outputs for formatting change above.

tests/invalid/no_method.{m,err_exp}:
    A new test case for an arity-related error message that wasn't
    being exercised before.

tests/invalid/Mmakefile:
    Enable the new test case.
2022-02-17 22:21:16 +11:00
Zoltan Somogyi
dd632327db Generalize component_list_to_line_pieces.
compiler/error_util.m:
    Do not automatically add an nl to the end of the output
    of component_list_to_line_pieces; instead, let the callers specify
    how the last line should end. Most will pass nl, but some will pass
    an nl_indent_delta to undo an earlier nl_indent_delta.

compiler/add_clause.m:
compiler/add_foreign_enum.m:
compiler/add_mode.m:
compiler/add_pragma.m:
compiler/error_msg_inst.m:
compiler/post_typecheck.m:
compiler/prog_foreign_enum.m:
compiler/typecheck_errors.m:
    Conform to the change in error_util.m.
2022-02-16 13:59:55 +11:00
Zoltan Somogyi
9a9067171d Move more pred name creation to pred_name.m.
compiler/pred_name.m:
    Add two more pred name transforms: one used by I/O tabling,
    and one used by stm_expand.m.

    Change the names we generate for I/O tabling to fit in with our schemes,
    because we can (there is no part of the whole Mercury system that looks for
    the names we *used* to construct.

    Leave the names we generate for stm as they are, even though they also
    do not fit into our scheme, because changing them would obsolete
    the documentation (such as it is) in stm_expand.m.

    Return the name of instance predicates as strings, rather than
    as always-unqualified sym_names.

    Return the name of instance predicates and uci (unify, compare and index)
    predicates as strings, rather than as always-unqualified sym_names.

compiler/hlds_pred.m:
    Change the interface of the pred_info_create predicate to put the
    pred_or_func indication before the pred name. I did this originally
    to flush out places that constructed predicate names without
    going through pred_name.m. However, I also took the opportunity
    to fix an old issue, which was that

    - pred_info_create took in a sym_name to specify the name of the
      new predicate, but
    - it ignored the module name part of the sym_name, using a separately
      passed module name instead.

    This definitely violates the law of least astonishment.

    I change the interface of both pred_info_create and pred_info_init
    (which also had a similar issue, using the separately-passed module name
    only if the sym_name specifying the name was unqualified) to require
    their callers to decide the module name part of the name of the new pred,
    and pass it alongside the name that it qualifies. The changes to do this
    ended up being the bulk of the diff. (The define_new_pred predicate should
    also have this treatment applied to it, but that would have made the diff
    even larger.)

compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_pragma_tabling.m:
compiler/add_pred.m:
    Conform to the changes above. Use variable names that distinguish
    raw names (strings) from sym_names.

    Require the sym_names in item_clause_infos, item_pred_decl_infos,
    item_mode_decl_infos, and various pragma_info_xyzs to be qualified.
    The parsing predicates that generate them implicitly qualify them
    if the name in the source code is unqualified.

    Delete the code that generated an error message when handed an
    item_pred_decl_info containing an unqualified sym_name. Due to
    the implicit quantification mentioned above, this can't happen.

    When adding foreign_procs to the HLDS, use the module name that
    came with the foreign_proc (which could have been explicit or implicit),
    *not* the name of the current module (which is what we used to use),
    when generating error messages. This difference could make the error
    message quite misleading. (We did not have a test case for this error
    message.)

compiler/add_pragma_type_spec.m:
    Conform to the changes above. Use variable names that distinguish
    raw names (strings) from sym_names.

    When adding adding type-specialized versions of predicates to the HLDS,
    use the module name that was created in parse_pragma.m; do not override
    it with the name of the module qualifier of the original predicate.
    If parse_pragma.m did its job right, the two should always be the same.

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

    Add an XXX for a questionable module qualifier we specify for a unify,
    compare or index predicate.

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

    Fix a variable version issue that caused progress messages to be
    printed at an unexpected time.

compiler/structure_reuse.versions.m:
    Conform to the changes above.

    Simplify the too-complex structure of the code that constructs
    predicate names.

compiler/accumulator.m:
compiler/check_typeclass.m:
compiler/dep_par_conj.m:
compiler/lambda.m:
compiler/par_loop_control.m:
compiler/stm_expand.m:
compiler/table_gen.m:
compiler/unused_args.m:
    Conform to the changes above.

compiler/make_hlds_error.m:
    Take the pred_or_func indicator before the predicate name.
    Use variable names that distinguish raw names (strings) from sym_names.

compiler/parse_util.m:
    Fix a missing undo of an nl_indent_delta.

compiler/foreign.m:
    Add a note about a predicate, that as far I can tell has not done
    anything useful for years, if not decades, is now unused. (This diff
    comments out the only call to it, in add_foreign_proc.m.) The only
    thing it *could* do was warn about a foreign_proc not being able
    to be implemented for the current target language, but that test
    in now done way earlier in the process, and foreign.m does not
    get called in any situation in which the message would be relevant.
2022-02-15 19:53:22 +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
bd0b747f6e Use explicit streams in several modules.
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_pragma_tabling.m:
compiler/check_libgrades.m:
compiler/deep_profiling.m:
compiler/goal_expr_to_goal.m:
compiler/options_file.m:
compiler/pickle.m:
compiler/process_util.m:
compiler/state_var.m:
compiler/superhomogeneous.m:
    Ad above.

compiler/Mercury.options:
    Do not pass --no-warn-implicit-stream-calls when compiling these modules.

compiler/analysis.file.m:
compiler/mercury_compile_main.m:
    Conform to the changes above.
2021-06-08 16:44:06 +10:00
Zoltan Somogyi
715121485c Don't import unneeded modules in the interface. 2021-05-29 12:55:02 +10:00
Zoltan Somogyi
a72627888e Make the goal_type type more fit for purpose.
compiler/hlds_pred.m:
    Separate out goal types that implement a promise from those that do not.
    Document the latter. (The former is documented elsewhere.)

    When creating a new predicate, require the caller to specify
    the goal type; do not supply a default that may be wrong.

    Give some predicates more meaningful names.

compiler/add_pred.m:
    When adding an implicit predicate declaration for a promise,
    specify that the new predicate is for a promise, instead of letting
    hlds_pred.m assume by default that it is NOT for a promise.

compiler/add_clause.m:
    When adding a clause to the HLDS, do not require callers to supply
    information that they cannot possibly know.

    Specify the goal_type for a promise when creating its predicate,
    not later.

compiler/pre_typecheck.m:
    Record the goal type of field access functions, whose Mercury definition
    we just created, as containing only Mercury code. Previously, we falsely
    recorded it as containing both Mercury clauses and foreign procs.

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_foreign_proc.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_special_pred.m:
compiler/check_promise.m:
compiler/check_typeclass.m:
compiler/intermod.m:
compiler/lambda.m:
compiler/make_hlds_passes.m:
compiler/par_loop_control.m:
compiler/purity.m:
compiler/stm_expand.m:
compiler/structure_reuse.versions.m:
compiler/table_gen.m:
compiler/typecheck.m:
compiler/untupling.m:
    Conform to the changes above.
2021-05-20 00:46:18 +10:00
Zoltan Somogyi
552518da43 Break up a 200-line predicate.
Put related predicates next to each other.

Give some predicates and variables better names.
2021-05-19 19:12:48 +10:00
Zoltan Somogyi
094d6ab0f7 Add clauses by item_clause_info.
compiler/add_clause.m:
    Change the signature of the predicate that adds clauses to the HLDS
    to take its input in the form of an item_clause_info, instead of a
    bunch of separate arguments.

    Change the signature of the predicate that adds clauses to a clauses_info
    to put the original and updated versions of the same data structure
    next to each other, as with state variables. (It cannot usefully take
    its input in the form of an item_clause_info.)

compiler/add_pred.m:
    Fix weird argument order in some predicates.

compiler/add_class.m:
compiler/add_foreign_proc.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma_tabling.m:
compiler/make_hlds_passes.m:
    Conform to the changes above.
2021-05-19 17:45:56 +10:00
Zoltan Somogyi
99334e8469 Switch to structured item sequence numbers.
compiler/prog_data.m:
    Define a data type that encodes the distinction between valid
    and dummy item sequence numbers in the type. Previously, different
    parts of the compiler expressed this distinction in two different ways,
    either using "-1" to represent a dummy sequence number, or using "no"
    in a maybe(int) type.

compiler/prog_item.m:
    Use the new type instead of plain "int" as the sequence number in items.

compiler/hlds_pred.m:
    Use the new type instead of plain "int" as the sequence number
    in cur_user_decl_infos. Document the fact that the presence of a
    cur_user_decl_info in a pred_info does NOT guarantee a valid
    item sequence number.

compiler/add_foreign_proc.m:
    When adding a foreign_proc to the HLDS, pass a whole item_pragma_info,
    not its components. (This change is what this diff started as, before
    the item_seq_num changes overwhelmed it.)

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_clause.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma.m:
compiler/add_pragma_tabling.m:
compiler/add_pred.m:
compiler/add_solver.m:
compiler/add_special_pred.m:
compiler/check_typeclass.m:
compiler/comp_unit_interface.m:
compiler/decide_type_repn.m:
compiler/default_func_mode.m:
compiler/hlds_clauses.m:
compiler/intermod.m:
compiler/item_util.m:
compiler/lambda.m:
compiler/make_hlds_passes.m:
compiler/par_loop_control.m:
compiler/parse_class.m:
compiler/parse_dcg_goal.m:
compiler/parse_inst_mode_defn.m:
compiler/parse_item.m:
compiler/parse_module.m:
compiler/parse_mutable.m:
compiler/parse_pragma.m:
compiler/parse_pragma_analysis.m:
compiler/parse_pragma_foreign.m:
compiler/parse_pragma_tabling.m:
compiler/parse_type_defn.m:
compiler/parse_type_repn.m:
compiler/parse_types.m:
compiler/proc_requests.m:
compiler/prog_mutable.m:
compiler/split_parse_tree_src.m:
compiler/stm_expand.m:
compiler/style_checks.m:
compiler/table_gen.m:
    Conform to the changes above.
2021-05-19 13:27:27 +10:00
Zoltan Somogyi
94f475f9d7 Allow prog_out.m's callers to use explicit streams.
compiler/prog_out.m:
    For every predicate that writes output to the current output stream,
    ensure that there is another predicate with the same name that takes
    an explicit stream as an additional arguments.

    Some of these predicates already existed under different names,
    but that name difference prevents --warn-implicit-stream-calls
    from warning about the implicit stream use. Fix that.

    Delete write_quoted_module_name, since it is a synonym for
    write_quoted_sym_name (since the compiler' current code depends on
    module_name being a synonym for sym_name in lots of places already).

compiler/add_clause.m:
compiler/analysis.file.m:
compiler/closure_analysis.m:
compiler/higher_order.m:
compiler/make.module_dep_file.m:
compiler/make.program_target.m:
compiler/pd_debug.m:
compiler/recompilation.check.m:
compiler/smm_common.m:
compiler/source_file_map.m:
compiler/structure_reuse.indirect.m:
    Conform to the changes in prog_out.m. There is no switchover
    to explicit streams in this diff; that will come later.
2021-03-25 09:43:02 +11:00
Zoltan Somogyi
5f50259d16 Write to explicitly named streams in many modules.
Right now, most parts of the compiler write to the "current output stream".
This was a pragmatic choice at the time, but has not aged well. The problem
is that the answer to the question "where is the current output stream going?"
is not obvious in *all* places in the compiler (although it is obvious in
most). When using such implicit streams, finding where the output is going
to in a given predicate requires inspecting not just the ancestors of that
predicate, but also all their older siblings (since any of them could have
changed the current stream), *including* their entire call trees. This is
usually an infeasible task. By constrast, if we explicitly pass streams
to all output operations, we need only follow the places where the variable
representing that stream is bound, which the mode system makes easy.

This diff switches large parts of the compiler over to doing output only
to explicitly passed streams, never to the implicit "current output stream".
The parts it switches over are the parts that rely to a significant degree
on the innermost change, which is to the "output" typeclass in
parse_tree_out_info.m. This is the part that has to be switched over to
explicit streams first, because (a) many modules such as mercury_to_mercury.m
rely on the output typeclass, and (b) most other modules that do output
call predicates in these modules. Starting anywhere else would be like
building a skyscraper starting at the top.

This typeclass, output(U), has two instances: output(io), and output(string),
so you could output either to the current output stream, or to a string.
To allow the specification of the destination stream in the first case,
this diff changes the typeclass to output(S, U) with a functional dependency
from U to S, with the two instances being output(io.text_output_stream, io)
and output(unit, string). (The unit arg is ignored in the second case.)

There is a complication with the output typeclass method, add_list, that
outputs a list of items. The complication is that each item is output
by a predicate supplied by the caller, but the separator between the items
(usually a comma) is output by add_list itself. We don't want to give
callers of this method the opportunity to screw up by specifying (possibly
implicitly) two different output streams for these two purposes, so we want
(a) the caller to tell add_list where to put the separators, and then
(b) for add_list, not its caller, tell the user-supplied predicate what
stream to write to. This works only if the stream argument is just before
the di,uo pair of I/O state arguments, which differs from our usual practice
of passing the stream at or near the left edge of the argument list,
not near the right. The result of this complication is that two categories
of predicates that are and are not used to print items in a list differ
in where they put the stream in their argument lists. This makes it easy
to pass the stream in the wrong argument position if you call a predicate
without looking up its signature, and may require *changing* the argument
order when a predicate is used to print an item in a list for the first time.
A complete switch over to always passing the stream just before !IO
would fix this inconsistency, but is far to big a change to make all at once.

compiler/parse_tree_out_info.m:
    Make the changes described above.

    Add write_out_list, which is a variant of io.write_list specifically
    designed to address the "complication" described above. It also has
    the arguments in an order that is better suited for higher-order use.

    Make the same change to argument order in the class method add_list
    as well.

Almost all of the following changes consist of passing an extra stream
argument to output predicates. In some places, where I thought this would
aid readability, I replaced sequences of calls to output predicates
with a single io.format.

compiler/prog_out.m:
    This module had many predicates that wrote things to the current output
    stream. This diff adds versions of these predicates that take an
    explicit stream argument.

    If the originals are still needed after the changes to the other modules,
    keep them, but add "_to_cur_stream" to the end of their names.
    Otherwise, delete them. (Many of the changes below replace
    write_xyz(..., !IO) with io.write_string(Stream, xyz_to_string(...), !IO),
    especially when write_xyz did nothing except call xyz_to_string
    and wrote out the result.)

compiler/c_util.m:
    Add either an explicit stream argument to the argument list, or a
    "_current_stream" suffix to the name, of every predicate defined
    in this module that does output.

    Add a new predicate to print out the block comment containing
    input for mkinit. This factors out common code in the LLDS and MLDS
    backends.

compiler/name_mangle.m:
    Delete all predicates that used to write to the current output stream,
    after replacing them if necessary with functions that return a string,
    which the caller can print to wherever it wants. (The "if necessary"
    part is there because some of the "replacement" functions already
    existed.)

    When converting a proc_label to a string, *always* require the caller
    to say whether the label prefix should be added to the string,
    instead of silently assuming "yes, add it", as calls to one of the old,
    now deleted predicates had it.

compiler/file_util.m:
    Add output_to_file_stream, a version of output_to_file which
    simply passes the output file stream it opens to the predicate
    that is intended to define the contents of the newly created or
    updated file. The existing output_to_file, which instead sets
    and resets the current output stream around the equivalent
    predicate call, is still needed e.g. by the MLDS backend,
    but hopefully for not too long.

compiler/mercury_to_mercury.m:
compiler/parse_tree_out.m:
compiler/parse_tree_out_clause.m:
compiler/parse_tree_out_inst.m:
compiler/parse_tree_out_pragma.m:
compiler/parse_tree_out_pred_decl.m:
compiler/parse_tree_out_term.m:
compiler/parse_tree_out_type_repn.m:
    Change the code writing out parse trees to explicitly pass a stream
    to every predicate that does output.

    In some places, this allows us to avoid changing the identity
    of the current output stream.

compiler/hlds_out.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_mode.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/intermod.m:
    Change the code writing out HLDS code to explicitly pass a stream
    to every predicate that does output. (The changes to these modules
    belong in this diff because these modules call many of the output
    predicates in the parse tree package.)

    In hlds_out_util.m, delete some write_to_xyz(...) predicates that wrote
    the result of xyz_to_string(...) to the current output stream.
    Replace calls to the deleted predicates with calls to io.write_string
    with the string being written being computed by xyz_to_string.

    Add a predicate to hlds_out_util.m that outputs a comment containing
    the current context, if it is valid. This factors out code that used
    to be common to several of the other modules.

    In a few places in hlds_out_module.m, the new code generates a
    slighly different set of blank lines, but this should not be a problem.

compiler/layout_out.m:
compiler/llds_out_code_addr.m:
compiler/llds_out_data.m:
compiler/llds_out_file.m:
compiler/llds_out_global.m:
compiler/llds_out_instr.m:
compiler/llds_out_util.m:
compiler/opt_debug.m:
compiler/rtti_out.m:
    Change the code writing out the LLDS to explicitly pass a stream
    to every predicate that does output. (The changes to these modules
    belong in this diff because layout_out.m and rtti_out.m call
    many of the output predicates in the parse tree package,
    and through them, the rest of the LLDS backend is affected as well.)

compiler/make.module_dep_file.m:
compiler/mercury_compile_main.m:
compiler/mercury_compile_middle_passes.m:
    Replace code that sets and resets the current output stream
    with code that simply passes an explicit output stream to a
    predicate that now *takes* an explicit stream as an argument.

compiler/accumulator.m:
compiler/add_clause.m:
compiler/code_gen.m:
compiler/code_loc_dep.m:
compiler/cse_detection.m:
compiler/delay_partial_inst.m:
compiler/dep_par_conj.m:
compiler/det_analysis.m:
compiler/error_msg_inst.m:
compiler/export.m:
compiler/format_call.m:
compiler/goal_expr_to_goal.m:
compiler/ite_gen.m:
compiler/lco.m:
compiler/liveness.m:
compiler/lp_rational.m:
compiler/mercury_compile_front_end.m:
compiler/mercury_compile_llds_back_end.m:
compiler/mlds_to_c_file.m:
compiler/mlds_to_c_global.m:
compiler/mode_debug.m:
compiler/mode_errors.m:
compiler/modes.m:
compiler/optimize.m:
compiler/passes_aux.m:
compiler/pd_debug.m:
compiler/pragma_c_gen.m:
compiler/proc_gen.m:
compiler/prog_ctgc.m:
compiler/push_goals_together.m:
compiler/rat.m:
compiler/recompilation.m:
compiler/recompilation.usage.m:
compiler/recompilation.version.m:
compiler/rtti.m:
compiler/saved_vars.m:
compiler/simplify_goal_conj.m:
compiler/stack_opt.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.domain.m:
compiler/structure_reuse.indirect.m:
compiler/structure_sharing.analysis.m:
compiler/superhomogeneous.m:
compiler/term_constr_build.m:
compiler/term_constr_data.m:
compiler/term_constr_fixpoint.m:
compiler/term_constr_pass2.m:
compiler/term_constr_util.m:
compiler/tupling.m:
compiler/type_assign.m:
compiler/unneeded_code.m:
compiler/write_deps_file.m:
    Conform to the changes above, mostly by passing streams explicitly.

compiler/hlds_dependency_graph.m:
    Conform to the changes above, mostly by passing streams explicitly.
    Move a predicate's definition next it only use.

compiler/Mercury.options:
    Specify --warn-implicit-stream-calls for all the modules in which
    this diff has replaced all implicit streams with explicit streams.
    (Unfortunately, debugging this diff has shown that --warn-implicit-
    stream-calls detects only *some*, and not *all*, uses of implicit
    streams.)

library/term_io.m:
    Fix documentation.
2020-11-14 15:07:55 +11:00
Zoltan Somogyi
4f32c50822 Let clauses with unknown warnings be processed.
This implements Mantis feature request #497.

compiler/parse_goal.m:
compiler/parse_dcg_goal.m:
    When we find that a disable_warnings scope contains an unrecognized
    warning name, generate a warning for it, and return this warning
    *alongside*, not *instead of*, the disable_warnings scope goal.
    This requires passing around not a maybe1(goal), as we have been doing
    till now, but a maybe2(goal, list(warning_spec)), so this change
    affects both (1) most of these two modules, and (2) most of the
    modules below.

compiler/error_util.m:
    Provide warning_spec as a synonym for error_spec, to be used in
    situations like this where the "error_spec" is intended contain
    something with severity_warning.

compiler/maybe_error.m:
    Provide some new utility predicates now needed in parse_goal.m
    and elsewhere.

compiler/prog_item.m:
    Provide room in the representation of clauses for the warnings
    generated by parsing the clause body goal.

compiler/add_class.m:
compiler/add_clause.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma_tabling.m:
compiler/du_type_layout.m:
compiler/get_dependencies.m:
compiler/make_hlds_passes.m:
compiler/parse_item.m:
compiler/parse_tree_out_clause.m:
compiler/prog_item_stats.m:
compiler/superhomogeneous.m:
    Conform to the changes above.

tests/valid/unknown_warning.m:
    Add this test case that checks whether a source file with an unknown
    warning name in a disable_warnings scope can have code generated for it.

tests/warnings/unknown_warning.{m,exp}:
    Add the same source file to this directory as well, to check whether
    we get the right set of warnings.

tests/valid/Mmakefile:
tests/valid/Mercury.options:
tests/warnings/Mmakefile:
    Enable the two new test cases.
2020-04-05 19:09:31 +10:00
Zoltan Somogyi
3a1ed2efcb Replace simple_call_id with pf_sym_name_arity.
compiler/prog_data.m:
    Delete the simple_call_id data type, since it is isomorphic
    to the pf_sym_name_arity type, which more clearly specifies
    what is stored inside it.

compiler/prog_out.m:
    Rename (all three versions of) simple_call_id_to_string to
    pf_sym_name_orig_arity_to_string, both to conform to the change
    in the input data type, and to emphasize that the resulting string
    will contain the *original* arity of functions (which does not include
    the return value), which is one less than the arity in the
    pf_sym_name_arity structure (which, in accordance with the
    convention inside the compiler that the arity is the length
    of the argument list, *does* include the return value).

    Delete the provision inside simple_call_id_to_string, now
    pf_sym_name_orig_arity_to_string, for special handling of the names
    of the predicates we use to implement promises, because it seems that
    *none* of the call sites to any of the three versions of this function
    can actually pass to it the identity of such a predicate. These calls
    refer to a predicate or mode declaration item (which promise predicates
    do not have), to clause or foreign_proc items (which again, promise
    predicates cannot have) or calls to the predicate (promise predicates
    cannot be called).

    Delete the exported predicate simple_call_id_to_sym_name_arity.
    It was called from exactly one place, inside prog_out.m itself,
    and this diff inlines that call.

    Avoid unnecessary forwarding of work from prog_out.m to error_util.m.

    Delete (all three versions of) write_simple_call_id. The changes
    below replace all their (few) uses with calls to
    pf_sym_name_orig_arity_to_string.

compiler/error_util.m:
    Replace the simple_call() error piece with qual_pf_sym_name_orig_arity,
    and add a new version unqual_pf_sym_name_orig_arity. Their names
    explicitly say that they print the original arities of functions,
    also say whether they strip away any module qualification on the
    sym_name inside the pf_sym_name_arity. We prefer the unqual version
    in situations where the module qualifier is implicit, which usually means
    that it must be the same as the name of the module being compiled, because
    it reduces visual clutter for readers of error messages.

    Put {qual,unqual}_pf_sym_name_orig_arity next to their most closely
    related function symbols, {qual,unqual}_sym_name_arity, in the
    format_component type. (This yields a few inconsequential changes
    in the order of error_specs when sorted.)

compiler/add_class.m:
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/check_libgrades.m:
compiler/check_parse_tree_type_defns.m:
compiler/check_promise.m:
compiler/check_typeclass.m:
compiler/convert_parse_tree.m:
compiler/equiv_type.m:
compiler/goal_expr_to_goal.m:
compiler/hlds_data.m:
compiler/hlds_desc.m:
compiler/hlds_goal.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/hlds_pred.m:
compiler/inst_util.m:
compiler/llds_out_instr.m:
compiler/make.module_target.m:
compiler/make.program_target.m:
compiler/make_hlds_error.m:
compiler/make_hlds_warn.m:
compiler/mark_tail_calls.m:
compiler/ml_unify_gen_construct.m:
compiler/mlds_to_c_stmt.m:
compiler/mode_errors.m:
compiler/mode_info.m:
compiler/modecheck_util.m:
compiler/module_qual.collect_mq_info.m:
compiler/module_qual.qualify_items.m:
compiler/parse_item.m:
compiler/parse_module.m:
compiler/parse_type_repn.m:
compiler/polymorphism.m:
compiler/post_typecheck.m:
compiler/pre_quantification.m:
compiler/pred_table.m:
compiler/prog_item.m:
compiler/recompilation.version.m:
compiler/term_constr_build.m:
compiler/termination.m:
compiler/type_ctor_info.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
compiler/typecheck_info.m:
compiler/unify_gen_construct.m:
compiler/unused_imports.m:
    Conform to the changes above. Where I am pretty sure that in an error
    message, the module qualifier of a name must be the current module,
    use unqual_pf_sym_name_orig_arity instead of qual_pf_sym_name_orig_arity.

    Add some sanity checks where they seem appropriate.

    Replace sequences of io.write_strings with uses of io.format where this
    yields clearer code. (This is why there were no remaining calls to
    write_simple_call_id.)

    Shorten some too-long lines.

    In add_pred.m, make the order of some predicate definitions match
    the order of the calls to them.

tests/invalid/ambiguous_method.err_exp:
tests/invalid/ambiguous_method_2.err_exp:
tests/invalid/bad_pred_arity.err_exp:
tests/invalid/bad_sv_unify_msg.err_exp:
tests/invalid/bigtest.err_exp:
tests/invalid/bug113.err_exp:
tests/invalid/bug197.err_exp:
tests/invalid/bug278.err_exp:
tests/invalid/bug410.err_exp:
tests/invalid/bug476.err_exp:
tests/invalid/bug487.err_exp:
tests/invalid/complex_constraint_err.err_exp:
tests/invalid/constrained_poly_insts.err_exp:
tests/invalid/errors.err_exp:
tests/invalid/errors1.err_exp:
tests/invalid/errors2.err_exp:
tests/invalid/exported_mode.err_exp:
tests/invalid/field_syntax_error.err_exp:
tests/invalid/foreign_singleton.err_exp:
tests/invalid/funcs_as_preds.err_exp:
tests/invalid/imported_mode.err_exp:
tests/invalid/invalid_binary_literal.err_exp:
tests/invalid/invalid_float_literal.err_exp:
tests/invalid/invalid_hex_literal.err_exp:
tests/invalid/invalid_octal_literal.err_exp:
tests/invalid/make_opt_error.err_exp:
tests/invalid/missing_det_decls.err_exp:
tests/invalid/multimode_syntax.err_exp:
tests/invalid/null_char.err_exp:
tests/invalid/occurs.err_exp:
tests/invalid/record_syntax_errors.err_exp:
tests/invalid/ref_to_implicit_pred.err_exp:
tests/invalid/require_tailrec_1.err_exp:
tests/invalid/require_tailrec_1.err_exp2:
tests/invalid/require_tailrec_2.err_exp:
tests/invalid/require_tailrec_2.err_exp2:
tests/invalid/require_tailrec_3.err_exp:
tests/invalid/require_tailrec_3.err_exp2:
tests/invalid/state_vars_test2.err_exp:
tests/invalid/state_vars_test3.err_exp:
tests/invalid/state_vars_test5.err_exp:
tests/invalid/type_inf_loop.err_exp:
tests/invalid/typeclass_constraint_extra_var.err_exp:
tests/invalid/typeclass_mode_2.err_exp:
tests/invalid/typeclass_test_12.err_exp:
tests/invalid/typeclass_test_2.err_exp:
tests/invalid/typeclass_test_9.err_exp:
tests/invalid/types.err_exp:
tests/invalid/types2.err_exp:
tests/invalid/unbound_type_vars.err_exp:
tests/invalid/with_type.err_exp:
tests/invalid_purity/purity_nonsense.err_exp:
tests/invalid_purity/purity_nonsense2.err_exp:
tests/warnings/double_underscore.exp:
tests/warnings/pragma_source_file.exp:
tests/warnings/singleton_test.exp:
tests/warnings/singleton_test.exp2:
tests/warnings/singleton_test.exp3:
tests/warnings/singleton_test.exp4:
tests/warnings/singleton_test_state_var.exp:
tests/warnings/warn_return.exp:
tests/warnings/warn_return.exp2:
tests/warnings/warn_return.exp3:
tests/warnings/warn_succ_ind.exp:
tests/warnings/warn_succ_ind.exp2:
tests/warnings/warn_succ_ind.exp3:
tests/warnings/warn_succ_ind.exp4:
    Update all these expected output files. Most changes are due to
    predicate and function names no longer being module qualified when
    the module qualification is obvious. A few changes are due to the
    change in the relative ordering of the function symbols of the
    format_component type.

    For singleton_test, warn_return and warn_succ_ind in warnings,
    the changes to the non-C .exp files were done by hand, so they
    may have the wrong white space.
2020-03-16 12:10:28 +11:00
Zoltan Somogyi
5c52cf0cde Standardize on "sym_name_arity" ...
... replacing "sym_name_AND_arity".
2020-03-15 19:37:18 +11:00
Zoltan Somogyi
9789375cc5 Make pre-HLDS passes use file-kind-specific parse trees.
Replacing item blocks file-kind-specific kinds of section markers with
file-kind-specific parse trees has several benefits.

- It allows us to encode the structural invariants of each kind of file
  we read in within the type of its representation. This makes the detection
  of any accidental violations of those invariants trivial.

- Since each file-kind-specific parse tree has separate lists for separate
  kinds of items, code that wants to operate on one or a few kinds of items
  can just operate on those kinds of items, without having to traverse
  item blocks containing many other kinds of items as well. The most
  important consequence of this is not the improved efficiency, though
  that is nice, but the increased clarity of the code.

- The new design is much more flexible. For example, it should be possible
  to record that e.g. an interface file we read in as a indirect dependency
  (i.e. a file we read not because its module was imported by the module
  we are compiling, but because its module was imported by *another* imported
  module) should be used *only* for the purpose it was read in for. This should
  avoid situations where deleting an import of A from a module, because it
  is not needed anymore, leads the compiler to generate an error message
  about a missing import of module B. This can happen if (a) module B
  always *should* have been imported, since it is used, but (b) module A's
  import of module B lead to module B's interface being available *without*
  an import of B.

  Specifically, this flexibility should enable us to establish each module's
  .int file as the single source of truth about how values of each type
  defined in that module should be represented. When compiling each source
  file, this approach requires the compiler to read in that module's .int file
  but using only the type_repn items from that .int file, and nothing else.

- By recording a single parse tree for each file we have read, instead of
  a varying number of item blocks, it should be significantly easier to
  derive the contents of .d files directly from the records of those
  parse trees, *without* having to maintain a separate set of fields
  in the module_and_imports structure for that purpose. We could also
  trivially avoid any possibility of inconsistencies between these two
  different sources of truth. (We currently fill in the fields used to
  drive the generation of .d files using two different pieces of code,
  one used for --generate-dependencies and one used for all other invocations,
  and these two *definitely* generate inconsistent results, as the significant
  differences in .d files between (a) just after an invocation of
  --generate-dependencies and (b) just after any other compiler invocation
  can witness.)

This change is big and therefore hard to review. Therefore in many files,
this change adds "XXX CLEANUP" comments to draw attention to places that
have issues that should be fixed, but whose fixes should come later, in
separate diffs.

compiler/module_imports.m:
    The compiler uses the module_and_imports structure defined here
    to go from a raw compilation unit (essentially a module to be compiled)
    to an augmented compilation unit (a raw compilation unit together
    with all the interface and optimization files its compilation needs).
    We used to store the contents of both the source file and of
    the interface and optimization files in the module_and_imports structure
    as item blocks. This diff replaces all those item blocks with
    file-kind-specific parse trees, for the reasons mentioned above.

    Separate out the .int0 files of ancestors modules from the .intN
    files for N>0 of directly imported modules. (Their item blocks
    used to be stored in the same list.)

    Maintain a database of the source, interface and optimization files
    we have read in so far. We use it to avoid reading in interface files
    if we have already read in a file for the same module that contains
    strictly more information (either an interface file with a smaller
    number as a suffix, or the source file itself).

    Shorten some field names.

compiler/prog_item.m:
    Define data structures for storing information about include_module,
    import_module and use_module declarations, both in a form that allows
    the representation of possibly erroneous code in actual source files,
    and in checked-and-cleaned-up form which is guaranteed to be free
    of the relevant kinds of errors. Add a block comment at the start
    of the module about the need for this distinction.

    Define parse_tree_module_src, a data structure for representing
    the source code of a single module. This is different from the existing
    parse_tree_src type, which represents the contents of a single source file
    but which may contain *more* than one module, and also different from
    a raw_compilation_unit, which is based on item blocks and is thus
    unable to express to invariants such as "no clauses in the interface".

    Modify the existing parse_tree_intN types to express the distinction
    mentioned just above, and to unify them "culturally", i.e. if they
    store the same information, make them store it using the same types.

    Fix a mistake by allowing promises to appear in .opt files.
    I originally ruled them out because the code that generates .opt files
    does not have any code to write out promises, but some of the predicates
    whose clauses it writes out have goal_type_promise, which means that
    they originated as promises, and get written out as promises.

    Split the existing pragma item kind into three item kinds, which have
    different invariants applying to them.

    - The decl (short for declarative) pragmas give the compiler some
      information, such as that a predicate is obsolete or that we
      want to type specialize some predicate or function, that is in effect
      part of the module's interface. Decl pragmas may appear in module
      interfaces, and the compiler may put them into interface files;
      neither statement is true of the other two kinds of pragmas.

    - The impl (short for implementation) pragmas are named so
      precisely because they may appear only in implementation sections.
      They give the compiler information that is private to that module.
      Examples include foreign_decls, foreign_codes, foreign_procs,
      and promises of clause equivalence, and requests for inlining,
      tabling etc. These will never be put into interface files,
      though some of them can affect the compilation of other modules
      by being included in .opt files.

    - The gen (short for generated) pragmas can never (legally) appear
      in source files at all. They record the results of compiler
      analyses e.g. about which arguments of a predicate are unused,
      or what exceptions a function can throw, and accordingly they
      should only ever occur in compiler-generated interface files.

    Use the new type differences between the three kinds of pragmas
    to encode the above invariants about which kinds of pragmas can appear
    where into the various kinds of parse trees.

    Make the augmented compilation unit, which is computed from
    the final module_and_imports structure, likewise switch from
    storing item blocks to storing the whole parse trees of the
    files that went into its construction. With each such parse tree,
    record *why* we read it, since this controls what permissions
    the source module being compiled has for access to the entities
    in the parse tree.

    Simplify the contains_foreign_code type, since one of three
    function symbols was equivalent to one possible use of another
    function symbol.

    Provide a way to record which method of which class a compiler-generated
    predicate is for. (See hlds_pred.m below.)

    Move the code of almost all utility operations to item_util.m
    (which is imported by many fewer modules than prog_item.m),
    keeping just the most "popular" ones.

compiler/item_util.m:
    Move most of the previously-existing utility operations here from
    prog_item.m, most in a pretty heavily modified form.

    Add a whole bunch of other utility operations that are needed
    in more than one other module.

compiler/convert_parse_tree.m:
    Provide predicates to convert from raw compilation units to
    parse_tree_module_srcs, and vice versa (though the reverse
    shouldn't be needed much longer).

    Update the conversion operations between the general parse_tree_int
    and the specific parse_tree_intN forms for the changes in prog_item.m
    mentioned above. In doing so, use a consistent approach, based on
    new operations in item_util.m, to detect errors such as duplicate
    include_module and import/use_module declarations in all kinds
    of parse trees.

    Enforce the invariants that the types of parse trees of various kinds
    can now express in types, generating error messages for their violations.

    Delete some utility operations that have been moved to item_util.m
    because now they are also needed by other modules.

compiler/grab_modules.m:
    Delete code that did tests on raw compilation units that are now done
    when that raw compilation unit is converted to a parse_tree_module_src.
    Use the results of the checks done during that conversion to decide
    which modules are imported/used and in which module section.

    Record a single reason for why we reading in each interface and
    optimization file. The code of make_hlds_separate_items.m will use
    this reason to set up the appropriate permissions for each item
    in those files.

    Use separate code for handling different kinds of interface and
    optimization files. Using generic traversal code was acceptable economy
    when we used the same data structure for every kind of interface file,
    but now that we *can* express different invariants for different kinds
    of interface and optimization file, we want to execute not just different
    code for each kind of file, but the data structures we want to work on
    are also of different types. Using file-kind-specific code is a bit
    longer, but it is significantly simpler and more robust, and it is
    *much* easier to read and understand.

    Delete the code that separates the parts of the implementation section
    that are exported to submodules, and the part that isn't, since that task
    is now done in make_hlds_separate_items.m.

    Pass a database of the files we have read through the relevant predicates.

    Give some predicates more meaningful names.

compiler/notes/interface_files.html:
    Note a problem with the current operation of grab_modules.

compiler/get_dependencies.m:
    Add operations to gather implicit references to builtin modules
    (which have to be made available even without an explicit import_module
    or use_module declaration) in all kinds of parse trees. These have
    more code overall, but will be at runtime, since we need only look at
    the item kinds that may *have* such implicit references.

    Add a mechanism to record the result of these gathering operations
    in import_and_or_use_maps.

    Give some types, function symbols, predicates and variables
    more meaningful names.

compiler/make_hlds_separate_items.m:
    When we stored the contents of the source module and the
    interface and optimization files we read in to augment it
    in the module_and_imports structure as a bunch of item blocks,
    the job of this module was to separate out the different kinds of items
    in the item blocks, returning a single list of each kind of item,
    with each such item being packaged up with its status (which encodes
    a set of permissions saying what the source module is allowed
    to do with it).

    Now that the module_and_imports structure stores this info in
    file-kind-specific parse trees, all of which have separate lists
    for each kind of item and none of which contain item blocks,
    the job of this module has changed. Now its job is to convert
    the reason why each file was read in into the (one or more) statuses
    that apply to the different kinds of items stored in it, wrap up
    each item with its status, and return the resulting overall list
    of status/item pairs for each kind of item.

compiler/read_modules.m:
    Add predicates that, when reading an interface file, return its contents
    in the tightest possible file-kind-specific parse tree.

    Refine the database of files we have read to allow us to store
    more file-kind-specific parse trees.

    Don't require that files in the database have associated timestamps,
    since in some cases, we read files we can put into the database
    *without* getting their timestamps.

    Allow the database to record that an attempt to read a file failed.

compiler/split_parse_tree_src.m:
    Rearchitect how this module separates out nested submodules from within
    the main module in a file.

    Another of the jobs of this module is to generate error messages for
    when module A includes module B twice, whether via nesting or via
    include_module declarations, with one special exception for the case
    where A's interface contains nested submodule A.B's interface,
    and A's implementation contains nested submodule A.B's implementation.
    The problem ironically was that while it reported duplicate include_module
    declarations as errors, split_parse_tree_src.m also *generated*
    duplicate include_module declarations. Since it replaced each nested
    submodule occurrence with an include_module declaration, in the scenario
    above, it generated two include_module declarations for A.B. Even worse,
    the interface incarnation of submodule A.B could contain
    (the interface of) its own nested submodule A.B.C, while its
    implementation incarnation could contain (the implementation section of)
    A.B.C. Each occurrence of A.B.C would be its only occurrence in the
    including part of its parent A.B, which means local tests for duplicates
    do not work. (I found this out the hard way.)

    The solution we now adopt adds include_module declarations to the
    parents of any submodule only once the parse tree of the entire
    file has been processed, since only then do we know all the
    includer/included relationships among nested modules. Until then,
    we just record such relationships in a database as we discover them,
    reporting duplicates when needed (e.g. when A includes B twice
    *in the same section*), but not reporting duplicates when not needed
    (e.g. when A.B includes A.B.C in *different* sections).

compiler/prog_data.m:
    Add a new type, pf_sym_name_and_arity, that exactly specifies
    a predicate or function. It is a clone of the existing simple_call_id
    type, but its name does NOT imply that the predicate or function
    is being called.

    Add XXXs that call for some other improvements in type names.

compiler/prog_data_foreign.m:
    Give a type, and the operations on that type, a more specific name.

compiler/error_util.m:
    Add an id field to all error_specs, which by convention should be
    filled in with $pred. Print out the value in this field if the compiler
    is invoked with the developer-only option --print-error-spec-id.
    This allows a person debugging the compiler find out where in the code
    an undesired error message is coming from significantly easier
    than was previously possible.

    Most of the modules that have changes only "to conform to the changes
    above" will be for this change. In many cases, the updated code
    will also simplify the creation of the affected error_specs.

    Fix a bug that looked for a phase in only one kind of error_spec.

    Add some utility operations needed by other parts of this change.

    Delete a previously internal function that has been moved to
    mdbcomp/prim_data.m to make it accessible in other modules as well.

compiler/Mercury.options:
    Ask the compiler to warn about dead predicates in every module
    touched by this change (at least in one its earlier versions).

compiler/add_foreign_enum.m:
    Replace a check for an inappropriately placed foreign_enum declaration
    with a sanity check, since with this diff, the error should be caught
    earlier.

compiler/add_mutable_aux_preds.m:
    Delete a check for an inappropriately placed mutable declaration,
    since with this diff, the error should be caught earlier.

compiler/add_pragma.m:
    Instead of adding pass2 and pass3 pragmas, add decl and impl and
    generated pragmas.

    Delete the tests for generated pragma occurring anywhere except
    .opt files, since those tests are now done earlier.

    Shorten some too-long predicate names.

compiler/comp_unit_interface.m:
    Operate on as specific kinds of parse trees as the interface of this
    module will allow. (We could operate on more specific parse trees
    if we changed the interface, but that is future work).

    Use the same predicates for handling duplicate include_module,
    import_module and use_module declarations as everywhere else.

    Delete the code of an experiment that shouldn't be needed anymore.

compiler/equiv_type.m:
    Replace code that operated on item blocks with code that operates
    on various kinds of parse trees.

    Move a giant block of comments to the front, where it belongs.

compiler/hlds_module.m:
    Add a field to the module_info that lets us avoid generating
    misleading error messages above missing definitions of predicates
    or functions when those definitions were present but were not
    added to the HLDS because they had errors.

    Give a field and its access predicates a more specific name.

    Mark a spot where an existing type cannot express everything
    it is supposed to.

compiler/hlds_pred.m:
    For predicates which the compiler creates to represent a class method
    (the virtual function, in OOP terms), record not just this fact,
    but the id of the class and of the method. Using this extra info
    in progress messages (with mmc -V) prevents the compiler from printing e.g.

        % Checking typeclass constraints on class method
        % Checking typeclass constraints on class method
        % Checking typeclass constraints on class method

    when checking three such predicates.

compiler/make.m:
    Provide a slot in the make_info structure to allow the database
    of the files we have read in to be passed around.

compiler/make_hlds_error.m:
    Delete predicates that are needed in just one other module,
    and have therefore been moved there.

compiler/make_hlds_passes.m:
    Add decl, impl and generated pragma separately, instead of adding
    pass2 and pass3 pragmas separately.

    Do not generate error messages for clauses, initialises or finalises
    in module interfaces, since with this diff, such errors should be
    caught earlier.

compiler/mercury_compile_main.m:
compiler/recompilation.check.m:
    Explicitly pass around the expanded database of parse trees
    of files that have been read in.

compiler/module_qual.collect_mq_info.m:
compiler/module_qual.m:
compiler/module_qual.qualify_items.m:
    Collect module qualification information, and do module qualification
    respectively on parse trees of various kinds, not item blocks.
    Take information about what the module may do with the contents
    of each interface or optimization file from the record of why
    we read that file, not from the section markers in item blocks.

    Break up some too-large predicates by carving smaller ones out of them.

compiler/options.m:
    Add an option to control whether errors and/or warnings detecting
    when deciding what should go into a .intN file be printed,
    thus (potentially) preventing the creation of that file.

    Add commented-out documentation for a previously totally undocumented
    option.

doc/user_guide.texi:
    Document the new option.

NEWS:
    Announce the new option.

    Mention that we now generate warnings for unused import_module and
    use_module declarations in the interface even if the module has
    submodules.

compiler/write_module_interface_files.m:
    Let the new option control whether we filter out any messages generated
    when deciding what should go into a .intN file.

compiler/parse_item.m:
    Delete actually_read_module_opt, since it is no longer needed;
    its callers now call actually_read_module_{plain,trans}_opt instead.

    Delete unneeded arguments from some predicates.

compiler/parse_module.m:
    Delete some long unused predicates.

compiler/parse_pragma.m:
    When parsing pragmas, wrap them up in the new decl, impl or generated
    pragma kinds.

compiler/parse_tree_out.m:
    Add predicates to write out each of the file-kind-specific parse trees.

compiler/parse_tree_out_pragma.m:
    Add predicates to write out decl, impl and generated pragmas.

compiler/polymorphism.m:
    Add a conditionally-enabled progress message, which can be useful
    in tracking down problems.

compiler/prog_item_stats.m:
    Conform NOT to the changes above beyond what is needed to let this module
    compile. Let that work be done the next time the functionality of
    this module is needed, by which time the affected data structures
    maybe have changed further.

compiler/typecheck.m:
    Fix a performance problem. With intermodule optimization, we read in
    .opt files, some of which (e.g. list.opt and int.opt) contain promises.
    These promises are read in as predicates with goal_type_promise,
    but they do not have declarations of the types of their arguments
    (since promises do not have declarations as such). Those argument types
    therefore have to be inferred. That inference replaces the original
    "I don't know" argument types with their actual types.

    The performance problem is that when we change the recorded argument types
    of a predicate, we require another loop over all the predicates in the
    module, so that any calls to this predicate can be checked against
    the updated types. This is as it should be for callable predicates,
    but promises are not callable. So if all the *only* predicates whose
    recorded argument types change during the first iteration to fixpoint
    are promises, then a second iteration is not needed, yet we used to do it.

    The fix is to replace the "Have the recorded types of this predicate
    changed?" boolean flag with a bespoke enum that says "Did the checking
    of this predicate discover a need for another iteration", and not
    setting it when processing predicates whose type is goal_type_promise.

compiler/typecheck_errors.m:
    Do not generate an error message for a predicate missing its clauses
    is the clauses existed but were not added to the HLDS because they were
    in the interface section.

    When reporting on ambiguities (when a call can match more than one
    predicate or function), sort the possible matches before reporting
    them.

compiler/accumulator.m:
compiler/add_class.m:
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_mode.m:
compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_type.m:
compiler/canonicalize_interface.m:
compiler/check_for_missing_type_defns.m:
compiler/check_parse_tree_type_defns.m:
compiler/check_promise.m:
compiler/check_raw_comp_unit.m:
compiler/check_typeclass.m:
compiler/common.m:
compiler/compile_target_code.m:
compiler/compiler_util.m:
compiler/dead_proc_elim.m:
compiler/deps_map.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/du_type_layout.m:
compiler/field_access.m:
compiler/find_module.m:
compiler/float_regs.m:
compiler/format_call.m:
compiler/goal_expr_to_goal.m:
compiler/handle_options.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/inst_check.m:
compiler/intermod.m:
compiler/introduce_parallelism.m:
compiler/layout_out.m:
compiler/make.dependencies.m:
compiler/make.module_dep_file.m:
compiler/make_hlds_warn.m:
compiler/mark_tail_calls.m:
compiler/mercury_compile_llds_back_end.m:
compiler/ml_top_gen.m:
compiler/mmakefiles.m:
compiler/mode_errors.m:
compiler/mode_robdd.equiv_vars.m:
compiler/modes.m:
compiler/module_qual.qual_errors.m:
compiler/oisu_check.m:
compiler/old_type_constraints.m:
compiler/options_file.m:
compiler/parse_class.m:
compiler/parse_dcg_goal.m:
compiler/parse_goal.m:
compiler/parse_inst_mode_defn.m:
compiler/parse_inst_mode_name.m:
compiler/parse_mutable.m:
compiler/parse_sym_name.m:
compiler/parse_type_defn.m:
compiler/parse_type_name.m:
compiler/parse_type_repn.m:
compiler/parse_types.m:
compiler/parse_util.m:
compiler/parse_vars.m:
compiler/post_term_analysis.m:
compiler/post_typecheck.m:
compiler/prog_event.m:
compiler/prog_mode.m:
compiler/purity.m:
compiler/qual_info.m:
compiler/recompilation.version.m:
compiler/resolve_unify_functor.m:
compiler/simplify_goal.m:
compiler/simplify_goal_call.m:
compiler/simplify_goal_disj.m:
compiler/simplify_goal_ite.m:
compiler/simplify_proc.m:
compiler/state_var.m:
compiler/stratify.m:
compiler/style_checks.m:
compiler/superhomogeneous.m:
compiler/table_gen.m:
compiler/term_constr_errors.m:
compiler/term_errors.m:
compiler/termination.m:
compiler/trace_params.m:
compiler/unused_args.m:
compiler/unused_imports.m:
compiler/write_deps_file.m:
compiler/xml_documentation.m:
    Conform to the changes above.

mdbcomp/prim_data.m:
    Move a utility function on pred_or_funcs here from a compiler module,
    to make it available to other compiler modules as well.

scripts/compare_s1s2_lib:
    A new script that helped debug this diff, and may help debug
    similar diffs the future. It can compare (a) .int* files, (b) .*opt
    files, (c) .mh/.mih files or (d) .c files between the stage 1 and
    stage 2 library directories. The reason for the restriction
    to the library directory is that any problems affecting the
    generation of any of these kinds of files are likely to manifest
    themselves in the library directory, and if they do, the bootcheck
    won't go on to compile any of the other stage 2 directories.

tests/debugger/breakpoints.a.m:
tests/debugger/breakpoints.b.m:
    Move import_module declarations to the implementation section
    when they are not used in the interface. Until now, the compiler
    has ignored this, but this diff causes the compiler to generate
    a warning for such misplaced import_module declarations even modules
    that have submodules. The testing of such warnings is not the point
    of the breakpoints test.

tests/invalid/Mercury.options:
    Since the missing_interface_import test case tests error messages
    generated during an invocation of mmc --make-interface, add the
    new option that *allows* that invocation to generate error messages.

tests/invalid/ambiguous_overloading_error.err_exp:
tests/invalid/max_error_line_width.err_exp:
tests/warnings/ambiguous_overloading.exp:
    Expect the updated error messages for ambiguity, in which
    the possible matches are sorted.

tests/invalid/bad_finalise_decl.m:
tests/invalid/bad_initialise_decl.m:
    Fix programming style.

tests/invalid/bad_item_in_interface.err_exp:
    Expect an error message for a foreign_export_enum item in the interface,
    where it should not be.

tests/invalid/errors.err_exp:
    Expect the expanded wording of a warning message.

tests/invalid/foreign_enum_invalid.err_exp:
    Expect a different wording for an error message. It is more "standard"
    but slightly less informative.

tests/invalid_submodules/children2.m:
    Move a badly placed import_module declaration, to avoid having
    the message the compiler now generates for it from affecting the test.

tests/submodules/parent2.m:
    Move a badly placed import_module declaration, to avoid having
    the message the compiler now generates for it from affecting the test.

    Update programming style.
2020-03-13 12:58:33 +11:00
Zoltan Somogyi
d5ade25753 Implement the obsolete_proc pragma.
While the existing obsolete pragma declares an entire predicate or function
obsolete, the new obsolete_proc pragma does this for only THE NAMED MODE
of a predicate or function.

NEWS:
doc/reference_manual.texi:
    Mention and document the new pragma.

compiler/prog_item.m:
    Add the new pragma. Rename the old pragma to "obsolete_pred". (This affects
    only the compiler's internal name; the user visible name stays the same.)

    Move a type definition next to its related types.

compiler/parse_pragma.m:
    Read in the new pragma.

compiler/hlds_pred.m:
    Create a slot in proc_infos for the information in the new pragma.

compiler/add_pragma.m:
    Add the new pragma to the HLDS.

    To avoid adding to the substantial existing code duplication in this
    module, factor out two commonly recurring pieces of code: one that
    looks up the (hopefully unique) pred_id specified by a pragma, and
    one that looks up and (if found) transforms the procedure specified
    by a pragma.

    Use error-message phraseology consistent with that employed by
    the newly-factored-out predicate even in places that cannot use them.

    Move the code handling foreign_export pragma here from add_foreign_proc.m
    to take advantage of the newly-factored out predicates.

compiler/add_foreign_proc.m:
    Delete the code moved to add_pragma.m.

    Fix the structure of the remaining code by putting related code fragments
    next to each other.

compiler/simplify_goal_call.m:
    Generate warnings to obsolete procedures as well as obsolete predicates.

compiler/parse_tree_out_pragma.m:
    Output the new pragma.

    Factor out existing common code.

compiler/hlds_code_util.m:
    Put a predicate's arguments into a more meaningful order.

compiler/make_hlds_error.m:
    Allow the caller of report_undefined_pred_or_func_error to specify
    whether the error applies to a predicate or a function. Most callers
    don't have that info, but some do, and using this info when available
    allows us to generate a more specific error message.

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

    Make a predicate easier to read by moving unimportant code out-of-line.

compiler/intermod.m:
    Conform to the changes above. Do this in a way that is adaptable to
    making intermod.m generate lists of items instead of simply writing
    stuff out, even though this makes the diff to this file more complex
    than immediately necessary.

compiler/add_mutable_aux_preds.m:
compiler/add_pragma_type_spec.m:
compiler/canonicalize_interface.m:
compiler/equiv_type.m:
compiler/get_dependencies.m:
compiler/item_util.m:
compiler/make_hlds_passes.m:
compiler/make_hlds_separate_items.m:
compiler/module_qual.qualify_items.m:
compiler/prog_data_pragma.m:
compiler/prog_item_stats.m:
compiler/recompilation.version.m:
    Conform to the changes above.

compiler/options.m:
    Provide a simple way for the configure script to test for the presence
    of this new addition.

tests/invalid/obsolete_proc_pragma.{m,err_exp}:
    A test case for the new pragma.

tests/invalid/Mmakefile:
tests/invalid/Mercury.options:
    Enable the new test case, and set it to run with --halt-at-warn.

tests/invalid/bug83.err_exp:
tests/invalid/require_tailrec_invalid.err_exp:
    Update these two files to expect updated error messages.
2019-10-23 05:04:41 +11:00
Zoltan Somogyi
b0897e95d5 Replace pairs of lists with lists of pairs.
After this diff, the compiler allocates very slightly more memory,
but in exchange it has to do fewer nil/cons tests. The overall result
on my laptop is a very slight speedup. (The impact has to be limited,
because the code involved takes much less than 1% of the compiler's runtime.)

compiler/superhomogeneous.m:
    The main predicate that breaks down terms into superhomogeneous form
    used to introduce unifications between corresponding elements of two lists:
    the list of argument terms in a call (maybe in the head of a clause,
    or maybe in its body), and a freshly made corresponding list
    of distinct variables. These lists had to have the same length,
    but this was enforced only via runtime checks.

    A variant of this predicate took a third input list as well,
    specifying the contexts of these arguments. This also had to have
    the same length, and again this was enforced only via runtime checks.

    Replace this approach with one that processes a list of pairs
    or triples, which encodes the "same length invariant" in the type.

    Make the predicate that allocates the distinct variable for each arg
    return the input needed by the new version of insert_arg_unifications.

compiler/hlds_goal.m:
    Add a predicate to initialize a goal_info's context *and* purity,
    for use by goal_expr_to_goal.m.

compiler/goal_expr_to_goal.m:
    Conform to the change in superhomogeneous.m.

    Factor out some comon code.

    Use the new predicate in hlds_goal.m.

compiler/add_clause.m:
compiler/field_access.m:
compiler/state_var.m:
    Conform to the change in superhomogeneous.m.
2019-10-01 14:55:20 +10:00
Zoltan Somogyi
48da2d3262 Print the in,out,ui,di,uo,mui,mdi,muo modes as such.
compiler/parse_tree_out_inst.m:
    When writing out modes for debugging purposes (in error messages,
    or in HLDS dumps), print "in" instead of "(free >> ground)"
    and similarly for out, ui, di, uo, mui, mdi and muo.

    When writing out modes for use by other invocations of the Mercury
    compiler, keep the output as it was.

compiler/mode_errors.m:
    When printing mode declarations, let the caller specify whether
    we are intending the output for humans or not.

compiler/mode_errors.m:
compiler/add_clause.m:
    Specify this parameter: generate output for machines when
    the exact form of the mode may be relevant, and for humans otherwise.

compiler/make_hlds_error.m:
    Delete two unused predicates, which were near-exact duplicates
    of (a) the predicate touched by the change to add_clause.m,
    and (b) its caller.

tests/invalid/bug410.err_exp:
tests/invalid/modes_erroneous.err_exp:
    Expect the human-friendly forms of in and out.
2019-06-22 12:41:21 +02:00
Zoltan Somogyi
c1bdd2100b Delete unneeded $module args from aborts. 2019-04-16 04:13:35 +10:00
Zoltan Somogyi
5eae909f78 Split hlds_cons.m from hlds_data.m.
compiler/hlds_cons.m:
compiler/hlds_data.m:
    Move the parts of hlds_data.m dealing with the cons table
    (representing the function symbols visible in the current module)
    and with the fields within those function symbols to the new module
    hlds_cons.m. This code was a large fraction of hlds_data.m, yet it is
    needed by relatively few modules.

compiler/hlds.m:
compiler/notes/compiler_design.html:
    Add and document the new module.

compiler/*.m:
    Import the new module as well as, or instead of, hlds_data.m.
2018-10-26 00:30:12 +11:00
Zoltan Somogyi
8303b503b6 Unify and compare packed args in bulk when possible.
compiler/unify_proc.m:
    Try to optimize the code we generate for unification and comparison
    predicates when a function symbol's arguments include sub-word-sized
    arguments packed together into a word.

    For unify predicates, generate code to test whether the two words
    at the same offset in the terms being unified are equal. This works
    regardless of whether the arguments are signed or unsigned.

    For compare predicates, generate code to compare the two words
    at the same offset in the terms being compared *if* all the arguments
    in the terms being compared are unsigned. This works because we put
    the earlier arguments in the more significant bit positions. But if
    some of the arguments are signed, then divide the argument word
    in sequences of zero or more unsigned arguments separated by signed
    arguments. We then generate code that compares any contiguous sequences
    of unsigned arguments in bulk, while comparing each signed field
    separately.

    Do the bulk unification and comparison via foreign_proc goals generated
    inline. This works only when we are generating C, but this is ok because
    we pack sub-word-sized arguments into a word only when generating C.

    We do the comparison of signed sub-word-sized fields (int8, int16 or int32)
    via foreign_proc goals generated inline as well. Doing them using unify
    goals would work as well, but would be less efficient in general. This is
    because having N such arguments in a function symbols requires storing
    only one value across calls for each term being compared (the term itself)
    when generating foreign_procs, but would require storing N values across
    calls (the values of the sub-word-sized signed arguments) when generating
    unifications. Generating inline foreign_procs is effectively a manual
    application of the optimization implemented by saved_vars.m.

library/private_builtin.m:
    Add the builtin predicates that unify_proc.m now generates calls to.

    We should never need their bodies, but the compiler does need to know
    the declarations of all predicates mentioned in inline foreign_procs.

configure.ac:
runtime/mercury_conf.h.in:
    Define either MR_MERCURY_IS_32_BITS or MR_MERCURY_IS_64_BITS depending
    on the word size. Make the configured value of MR_BITS_PER_WORD available
    to C code.

mdbcomp/program_representation.m:
    Register the new builtin predicates as no_typeinfo_builtins, i.e.
    builtins whose arguments' types contain type variables, that nevertheless
    should *not* be passed the typeinfos of the actual types bound to those
    type variables.

compiler/hlds_clauses.m:
    Bulk unification of arguments works only when all the arguments involved
    are initially ground. The optimized unification clauses we can now generate
    are thus appropriate only for <in,in> unifications. (Technically, they
    *would* work for unifications for which the function symbol arguments
    involved in bulk unify operations are ground even if some other arguments
    are initially free, but that distinction is too hard to make, compared
    to the extremely small performance gain that would be available
    if we *could* make that distinction.)

    Provide a way for unify_proc.m to mark a clause as being for use either
    in the <in,in> modes of unifications (for the optimized version using bulk
    unifications), or as in all other modes of unifications (for a version in
    which that optimization has been disabled).

    Replace two boolean fields in clauses_infos with bespoke types, for
    greater readability and reliability. These are a remnant of a different
    way to differentiate <in,in> vs non-<in,in> clauses that I ultimately
    decided against. These bespoke types are independent of the main change
    in this diff, but there is no reason to undo their use.

compiler/clause_to_proc.m:
    When copying clauses to procedure bodies inside type-specific unify
    predicates, pay attention to the markers that unify_proc.m put on
    those clauses about which are for <in,in> modes and which are for
    non-<in,in> modes.

    To make this possible, make our callers pass us extra information.

compiler/options.m:
    Add a bootstrapping option that governs whether unify_proc.m should
    try to apply the new optimization.

    Give an option that governs comparisons of function symbols for Erlang
    a name that reflects that fact.

compiler/hlds_pred.m:
    Fix a misleading predicate name.

compiler/add_class.m:
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/dead_proc_elim.m:
compiler/det_report.m:
compiler/erl_code_gen.m:
compiler/handle_options.m:
compiler/higher_order.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_statistics.m:
compiler/intermod.m:
compiler/mercury_compile_front_end.m:
compiler/ml_proc_gen.m:
compiler/modecheck_unify.m:
compiler/proc_gen.m:
compiler/proc_requests.m:
compiler/purity.m:
compiler/resolve_unify_functor.m:
compiler/structure_reuse.indirect.m:
compiler/structure_sharing.analysis.m:
compiler/tabling_analysis.m:
compiler/type_constraints.m:
compiler/typecheck.m:
compiler/unused_args.m:
    Conform to the changes above.
2018-10-03 08:32:29 +10:00
Zoltan Somogyi
678b226be8 Generate messages for some state var singletons.
compiler/state_var.m:
    Delete redundant copy unifications, whose mere presence can hide the fact
    that the state variable instance being copied is a singleton.

compiler/add_clause.m:
    Conform to the change in state_var.m.

compiler/hlds_goal.m:
    Add a new goal feature for state_var.m to use to identify the copy goals
    inserted by the state var transformation.

    Add a mechanism to add more than feature to a goal at a time.

compiler/saved_vars.m:
    Conform to the change to hlds_goal.m.

compiler/proc_gen.m:
    Fix a singleton ocurrence of a state variable. This problem was hidden
    until the bug fix in state_var.m described above.

tests/warnings/singleton_test_state_var.{m,exp}:
    New regression test to test for the original bug.

tests/warnings/Mmakefile:
    Enable the new test case.
2018-03-09 14:10:50 +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
Zoltan Somogyi
a79bdd9a6b Split clause_to_proc.m into three pieces.
compiler/default_func_mode.m:
compiler/introduce_exists_casts.m:
    Carve these two modules out of clause_to_proc.m. The code now in
    default_func_mode.m had no connection to the rest of clause_to_proc.m,
    while the code now in introduce_exists_casts.m has only a single call
    to a predicate defined in the left-over part of clause_to_proc.m.

compiler/clause_to_proc.m:
    Remove the code that has been moved elsewhere, and export that one
    predicate for introduce_exists_casts.m. This reduces clause_to_proc.m
    to less than half its former size.

compiler/check_hlds.m:
    Add introduce_exists_casts.m to the check_hlds package.

compiler/hlds.m:
    Add default_func_mode.m to the hlds package.

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

compiler/add_class.m:
compiler/add_clause.m:
compiler/du_type_layout.m:
compiler/make_hlds_passes.m:
compiler/modes.m:
compiler/polymorphism.m:
    Conform to the changes above.
2017-12-18 18:40:20 +11:00
Zoltan Somogyi
3dc5650844 Implicitly rename apart vars occurring only in trace goals.
At the moment, the compiler rejects code like the following

     p(A, B, X) :-
         trace [io(!IO)] (
             ToPrint = A,
             io.format("A = %d\n", [i(ToPrint)], !IO)
         ),
         trace [io(!IO)] (
             ToPrint = B,
             io.format("B = %d\n", [i(ToPrint)], !IO)
         ),
         X = A + B,
         trace [io(!IO)] (
             ToPrint = X,
             io.format("X = %d\n", [i(ToPrint)], !IO)
         ).

because the three trace goals each attempt to bind a variable (ToPrint)
that is not local to the trace goal. The compiler already contains
several predicates that contain two or more trace goals whose local
variables (usually intermediates between the raw data -such as X-
and the actual task of the trace goal -such as the call to io.format-)
had to be renamed because of this. This is annoying, and the error message
the compiler generates without the rename is also surprising; it goes
against people's expectations.

Fix this violation of the law of least astonishment by automatically
and implicitly renaming apart variables in clauses that (a) occur
only in trace goals, and (b) occur in more than one trace goal.

compiler/pre_quantification.m:
    This new module contains code to wrap an existential quantification
    around the body of a trace goal if that trace goal contains one of
    the above variables. The actual renaming will be done by the immediately
    following invocation of quantification.

compiler/hlds.m:
compiler/notes/compiler_design.html:
    Mention the new module.

compiler/Mercury.options:
    Allow the new module to compile until the recent improvement to
    unused_imports.m is installed.

compiler/add_clause.m:
    Invoke the new module on clauses being added to the HLDS if they
    contain any trace goals. (Most don't, so we don't invoke the new
    module on them.)

compiler/goal_expr_to_goal.m:
    When translating a trace goal from the parse tree form to the HLDS form,
    record this fact.

compiler/qual_info.m:
    Add a flag to the qual_info to provide the space for this recording.

tests/hard_coded/dup_vars_in_trace_scopes_only.{m,exp}:
    A test case for the new capability.

tests/hard_coded/Mmakefile:
    Enable the new test case.
2017-07-03 23:55:22 +02:00
Zoltan Somogyi
bc0f5de6e3 Fix an obsolete comment. 2017-06-29 12:34:33 +02:00
Zoltan Somogyi
7b82c59c40 Remove unneeded module qualifications from error messages.
This should make error messages easier to read by removing clutter.

compiler/error_util.m:
    Split each of the sym_name and sym_name_and_arity error pieces into two;
    one which prints any module qualification present in the given sym_name,
    and one which does not. This forces people who use these pieces
    to think about whether they want the sym_name module qualified
    in the error message or not.

compiler/add_class.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_pred.m:
compiler/add_type.m:
compiler/check_for_missing_type_defns.m:
compiler/check_promise.m:
compiler/check_raw_comp_unit.m:
compiler/check_typeclass.m:
compiler/det_report.m:
compiler/equiv_type.m:
compiler/format_call.m:
compiler/hlds_error_util.m:
compiler/inst_check.m:
compiler/introduce_parallelism.m:
compiler/make_hlds_error.m:
compiler/make_hlds_passes.m:
compiler/make_tags.m:
compiler/mercury_compile_main.m:
compiler/mode_errors.m:
compiler/modes.m:
compiler/module_qual.qual_errors.m:
compiler/modules.m:
compiler/oisu_check.m:
compiler/parse_inst_mode_defn.m:
compiler/parse_item.m:
compiler/parse_module.m:
compiler/parse_pragma.m:
compiler/parse_type_defn.m:
compiler/polymorphism.m:
compiler/post_term_analysis.m:
compiler/prog_out.m:
compiler/recompilation.check.m:
compiler/resolve_unify_functor.m:
compiler/split_parse_tree_src.m:
compiler/type_constraints.m:
compiler/typecheck_errors.m:
compiler/unused_args.m:
compiler/unused_imports.m:
    Conform to the change above. For sym_name references for which
    the module qualifier is obvious (usually because it *has* to be
    the module being compiled), change the reference to the variant
    that omits that qualifier; otherwise, keep the qualifier.

    In a few places, improve the wording of an error message.

tests/invalid/bad_instance.err_exp:
tests/invalid/bug17.err_exp:
tests/invalid/builtin_int.err_exp:
tests/invalid/foreign_purity_mismatch.err_exp:
tests/invalid/foreign_type_visibility.err_exp:
tests/invalid/fp_dup_bug.err_exp:
tests/invalid/fundeps_vars.err_exp:
tests/invalid/impl_def_literal_syntax.err_exp:
tests/invalid/inline_conflict.err_exp:
tests/invalid/inst_list_dup.err_exp:
tests/invalid/instance_no_type.err_exp:
tests/invalid/invalid_typeclass.err_exp:
tests/invalid/missing_interface_import.err_exp:
tests/invalid/missing_interface_import2.err_exp:
tests/invalid/oisu_check_semantic_errors.err_exp:
tests/invalid/tc_err1.err_exp:
tests/invalid/tc_err2.err_exp:
tests/invalid/transitive_import.err_exp:
tests/invalid/type_with_no_defn.err_exp:
tests/invalid/typeclass_bogus_method.err_exp:
tests/invalid/typeclass_missing_mode_2.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:
tests/invalid/types2.err_exp:
tests/invalid/undef_inst.err_exp:
tests/invalid/undef_mode.err_exp:
tests/invalid/undef_mode_and_no_clauses.err_exp:
tests/invalid/undef_type.err_exp:
tests/invalid/undef_type_mod_qual.err_exp:
tests/invalid/uu_type.err_exp:
tests/invalid/where_direct_arg.err_exp:
tests/invalid/where_direct_arg2.err_exp:
tests/invalid/wrong_type_arity.err_exp:
tests/recompilation/add_type_re.err_exp.2:
tests/recompilation/field_r.err_exp.2:
tests/recompilation/remove_type_re.err_exp.2:
tests/warnings/inst_with_no_type.exp:
    Expect the updated versions of error messages.
2017-04-01 20:20:57 +11:00
Zoltan Somogyi
253378fe21 Improve error messages for malformed lambda expressions.
Do this by insisting that terms whose top level(s) look like lambda
expressions should be parsed as lambda expressions, and return error
messages if that parsing attempt fails.

I did this is in several commits to modules in the parse_tree.m package
that translated terms to the parse tree, i.e. to goal_exprs. This diff
does the same thing for lambda expressions.

NEWS:
    Document this change, as well as other, similar changes in the recent past.

compiler/superhomogeneous.m:
    When translating a var-functor unification, which has the form
    X = f(Y1, ..., Yn), to the HLDS, we parse the right hand side term,
    looking for Mercury constructs such as lambda expressions and
    field accesses. We used to do this by checking if the RHS was
    a well-formed version of the construct we were looking for,
    and falling back to parsing it as an ordinary term. That meant that
    terms that the programmer *intended* to be lambda expressions,
    but which contained a syntax error, were not diagnosed during the
    construction of the HLDS, but during a later pass. Virtually always,
    that later pass was typechecking. Since in such cases, the typechecker
    is given terms whose function symbols were *intended* to be the "keywords"
    of Mercury constructs (to the extent that Mercury *has* keywords),
    not the names of data constructors or predicates, those error messages
    were almost always confusing, and at best an *indirect* indication
    of the actual problem with the code.

    This diff changes things so that when the top function symbol on
    the RHS of a unification is a Mercury "keyword" used only in lambda
    expressions, we commit to parsing it as such. If the parsing fails,
    we now generate an error message that describes the problem *directly*.

    To make the task of generating good error messages easier, and to make it
    possible to generate *consistent* error messages for the same error
    in different contexts, unify the four separate pieces of code that
    *used* to parse different kinds of lambda expressions. These four
    pieces of code used to parse

    - predicates defined using DCG notation;
    - predicates defined using non-DCG notation;
    - functions that used the default function mode and determinism; and
    - functions that did not use the default function mode and determinism.

    The unified code allows a function lambda expression to omit the
    default argument modes *independently* of whether it omits the default
    determinism, and vice versa. The old code did not do that: if you didn't
    explicitly specify one, you couldn't explicitly specify the other either,
    probably because it would have required two more pieces of code.

    The language reference manual says, in section 8.1:

        As with ‘:- func’ declarations, if the modes and determinism
        of the function are omitted in a higher-order function term, then
        the modes default to ‘in’ for the arguments, ‘out’ for
        the function result, and the determinism defaults to ‘det’.

    This text is vague on whether the modes and determinism are *allowed*
    to be omitted independently. The old behavior was a strict reading
    of this text. The new behavior follows the most liberal possible reading,
    and thus allows all the behaviors that the old one did, and more.

    Integrate the test for big integers that are too big to be represented
    with the conversion of all ordinary functors into cons_ids, both to
    simplify the code, and to speed it up. In the process, improve the
    error message for too-big integers.

compiler/add_clause.m:
    Don't try to generate warnings for singleton variables in a clause
    if the clause had syntax errors. Part of the parser's recovery from
    those syntax errors (e.g. when they occur in lambda expressions' clause
    heads) may have included not translating parts of the original term
    into the parsed clause body, so any such warnings could be misleading.

    Such warnings could also be correct, but I expect most programmers
    would prefer to miss some correct singleton warnings while the
    syntax errors are present in their code, and get them only once
    they have fixed those syntax errors, than to have to wade through
    misleading errors messages for the initial syntax error to get to
    the real ones.

compiler/field_access.m:
    Clarify the text of an error message.

    Delete a predicate that superhomogeneous.m no longer needs.

compiler/mercury_compile_front_end.m:
    Don't proceed past typechecking if the parser found syntax errors,
    since any errors we find later, e.g. as part of mode checking,
    are quite likely to be avalanche errors caused by those syntax errors.

    The reason why this wasn't a problem in the past is that when
    the program contained malformed uses of builtin constructs such as
    lambda expressions and field accesses, the parser used to simply
    transform the terms containing the malformed constructs into the arguments
    of call goals and unifications, and it was the typechecker that discovered
    that these function symbols did not match any declared type.
    The "type errors" generated for such problems told the compiler
    not to run later compiler passes to prevent avalanche errors.

    We now report syntax errors earlier, during the construction of the HLDS,
    and it is entirely possible that the parser's recovery from those errors
    leaves *no* type errors to be reported. This is why we need to make
    the presence of syntax errors in a predicate block the invocation
    of later passes.

compiler/typecheck.m:
    Return whether the predicates we typechecked had syntax errors,
    to make the change in mercury_compile_front_end.m possible.

compiler/state_var.m:
    If a lambda expression has two or more arguments of the form !X,
    we now print an error message for each, with each message naming the bad
    state variable and giving the context of the argument. We used to
    print only a single message saying that *some* argument misused
    state variables this way. Similarly, we now print the correct context
    for !X appearing as a function result, whether in a lambda expression
    or at the top level of a clause.

    The actual printing of those error messages takes place elsewhere,
    but change the utility predicates exported by state_var.m to make
    the change possible.

    Change the error message we generate for !X appearing as a function
    result, to avoid suggesting a possible repair that is virtually never
    the right repair.

compiler/mode_util.m:
    Delete a predicate that was used only by superhomogeneous.m; an updated
    version of that predicate is now in superhomogeneous.m itself.

compiler/module_qual.m:
compiler/module_qual.qualify_items.m:
    Instead of exporting predicates to module qualify the whole list of
    argument modes of a lambda expression, export predicates that module
    qualify only one such mode, since that is what superhomogeneous.m
    now wants.

compiler/hlds_clauses.m:
    Add access predicates for fields of the clauses_info type that previously
    did not have them, including the one that records the presence of syntax
    errors.

    Put related fields of the clauses_info together.

    Group both the declarations and the definitions of the access predicates
    together, and put them in the same order as the fields themselves.

compiler/add_class.m:
compiler/add_pred.m:
compiler/add_pragma_type_spec.m:
compiler/higher_order.m:
compiler/hlds_pred.m:
compiler/unify_proc.m:
    Conform to the changes above.

tests/invalid/lambda_syntax_error.err_exp:
    Print one error message for each of the four malformed lambda expressions
    in this test case, instead of the 13 avalanche messages we used to get
    from the typechecker, which tried to interpret the malformed lambda
    expression heads as calls, unifications etc.

    The motivation for this diff was a set of similar set of avalanche error
    messages for a real-life syntax error in a lambda expression in a change
    I worked on a while ago.

tests/benchmarks/deriv.{m,exp}:
    This test case used to use "^" as a data constructor (to represent
    raising X to the Nth power). Since the parser now insists on treating it
    as a field access operator, replace "^" with "power". (This test has
    the excuse of predating the addition of field access syntax to Mercury
    by several years.)

tests/dppd/grammar_impl.m:
    This test case used to define a type which contained "is" as a data
    constructor. After this diff, this is no longer allowed (as part of
    "is detism", it looks to the parser like the top constructor in a
    lambda expression head, and therefore as the top constructor of
    the lambda expression as a whole if it has no body), so add the type
    name as a prefix to this data constructor. To future-proof the test case,
    do the same with the several other data constructors that also duplicate
    the names of Mercury keywords.

tests/hard_coded/pprint_test2.{m,exp}:
tests/hard_coded/write.{m,exp}:
tests/hard_coded/write_binary.{m,exp}:
    These test cases used to define a type which contained ":-" as a data
    constructor. After this diff, this is no longer allowed, so replace them
    with "?-". (The tests check how io.m formats terms whose data constructor
    is an operator, so the replacement needs to be an operator, and Mercury
    syntax does not use "?-"; library/ops.m lists it as an operator only
    because it is an operator in Prolog.)

    Update write_binary.m to conform to our current style guide, and to avoid
    using the recently-deprecated io.make_temp.

tests/invalid/invalid_int.err_exp:
    Expect the updated text of the error message for a too-big
    integer constant.

tests/invalid/record_syntax_error.err_exp:
    Expect the updated text of the error message for a malformed field name.

tests/invalid/state_vars_test3.err_exp:
    Expect the updated text of the error message for a !X appearing
    as the result of a lambda function.

tests/invalid/state_vars_test4.err_exp:
    Expect the error message for a !X lambda argument, but (since we now
    stop after typechecking in the presence of such syntax errors),
    don't expect the avalanche error messages we used to print from the
    mode checker.
2016-05-20 05:47:36 +10:00
Zoltan Somogyi
9d4f1e6ae5 Avoid using some Mercury keywords.
compiler/pred_table.m:
compiler/prog_data.m:
    Avoid using / as a function symbol.

    Rename some function symbols to avoid ambiguity.

compiler/add_class.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_pred.m:
compiler/add_type.m:
compiler/check_for_missing_type_defns.m:
compiler/check_typeclass.m:
compiler/complexity.m:
compiler/det_report.m:
compiler/equiv_type.m:
compiler/error_util.m:
compiler/format_call.m:
compiler/hlds_error_util.m:
compiler/hlds_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/inst_check.m:
compiler/introduce_parallelism.m:
compiler/make_hlds_error.m:
compiler/make_hlds_passes.m:
compiler/make_tags.m:
compiler/mercury_to_mercury.m:
compiler/mode_errors.m:
compiler/modes.m:
compiler/module_qual.qual_errors.m:
compiler/oisu_check.m:
compiler/parse_mutable.m:
compiler/parse_sym_name.m:
compiler/parse_type_defn.m:
compiler/post_term_analysis.m:
compiler/prog_out.m:
compiler/recompilation.check.m:
compiler/recompilation.version.m:
compiler/resolve_unify_functor.m:
compiler/type_constraints.m:
compiler/typecheck_errors.m:
compiler/unused_args.m:
compiler/write_module_interface_files.m:
    Conform to the changes above.

    In a few places, improve the format of error messages.

tests/invalid/cyclic_typeclass.err_exp:
tests/invalid/cyclic_typeclass_2.err_exp:
tests/invalid/cyclic_typeclass_3.err_exp:
tests/warnings/inst_with_no_type.exp:
    Expect the updated error messages.
2016-05-13 11:46:37 +10:00
Zoltan Somogyi
41b97d2048 Generate better error messages for bad insts and modes.
compiler/parse_inst_mode_name.m:
    When trying to parse an inst or mode name and failing, we used to just
    print the whole term (including the correct parts) and a message about
    the mode being invalid. We now print a message for each incorrect *part*
    of a term, and make its message specific to the particular problem.

    Rename the predicates that parse insts and modes to include "parse"
    in their names, and make them take the additional arguments needed
    for detailed error reporting.

compiler/parse_sym_name.m:
    Put the arguments of a utility predicate in a more sensible order.

compiler/add_clause.m:
compiler/parse_class.m:
compiler/parse_inst_mode_defn.m:
compiler/parse_item.m:
compiler/parse_mutable.m:
compiler/parse_pragma.m:
compiler/parse_tree_out.m:
compiler/parse_type_defn.m:
compiler/parse_type_name.m:
compiler/parse_util.m:
compiler/superhomogeneous.m:
    Conform to the changes above. Make some minor improvements.

compiler/hlds_out_util.m:
    Add a utility predicate for use by the code above.

    Avoid throwing an unnecessary exception.

tests/invalid/combined_ho_type_inst.err_exp:
tests/invalid/impl_def_literal_syntax.err_exp:
tests/invalid/inst_list_dup.err_exp:
tests/invalid/multimode_dcg.err_exp:
tests/invalid/multimode_syntax.err_exp:
tests/invalid/predmode.err_exp:
tests/invalid/with_type.err_exp:
    Expect the improved error messages.
2016-04-26 14:50:18 +10:00
Zoltan Somogyi
7cd379659b Give some variables more meaningful names. 2016-04-10 10:31:21 +10:00