Commit Graph

62 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
18817d62d0 Record more than a pred_proc_id for each method.
Class and instance definitions both contain lists of methods,
predicates and/or functions, that each have one or more procedures.
Until now, we represented the methods in class and instance definitions
as lists of nothing more than pred_proc_ids. This fact complicated
several operations,

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

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

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

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

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

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

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

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

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

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

    Add some utility functions.

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

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

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

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

    Give some predicates better names.

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

    Give some predicates better names.

    Some error messages about problems in instance definitions started with

        In instance declaration for class/arity:

    while others started with

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

    Replace both with

        In instance declaration for class(foo, bar):

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

    Factor out some common code.

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

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

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

compiler/polymorphism_type_info.m:
    Fix some comment rot.

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

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

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

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

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

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

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

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

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

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

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

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

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

compiler/*.m:
    Conform to the changes above, mostly by updating import_module
    declarations, and renaming format_component to format_piece.
2022-10-12 20:50:16 +11:00
Zoltan Somogyi
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
26be4bb8e3 Add --warn-ambiguous-pragmas.
The new option is on by default, and it generates a warning about pragmas
that specify a name/arity pair that matches both a predicate and a function,
but does not say which one it is intended to apply to.

compiler/options.m:
doc/user_guide.texi:
    Add the new option.

NEWS:
    Announce the new option.

compiler/add_pragma.m:
    Implement the new option.

    Move to one predicate, get_matching_pred_ids, the code for dealing with
    both the absence of any matches, and the presence of more than one match,
    when looking up name/arity pairs in the predicate table. This allows us
    to delete the mostly-duplicate code fragments that did the same thing
    in all of get_matching_pred_ids's callers.

    Simplify the handling of conflicts between marker pragmas.

compiler/hlds_pred.m:
    Separate out no_inline decisions made by the compiler itself from
    the similar decisions made by users, in order to allow that simplification.

    Move the two inline markers next to each other.

compiler/make_hlds_error.m:
    Change a predicate called from add_pragma*.m to take user arities
    in their semantic form, not their int form, which raises the level
    of the predicate's interface, and factors out duplicate code in its
    callers.

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

doc/reference_manual.texi:
    Document pred(...) and func(...) wrappers around name/arity pairs
    in pragmas.

    Delete the commented out section on reserve_tag pragmas, which were
    deleted a while ago.

tests/invalid/inline_conflict.m:
    Expand this test case to test the *absence* of a warning for an
    ambiguous pragma with --no-warn-ambiguous-pragma.

tests/invalid/inline_conflict_warn.{m,err_exp}:
tests/invalid/Mercury.options:
    Add a copy of the inline_conflict test case to test the presence of
    a warning for an actually ambiguous pragma.

tests/invalid_nodepend/fact_table_in_interface.err_exp:
    Expect the updated wording of a warning.
2022-07-31 18:17:02 +10:00
Zoltan Somogyi
217820e50d Report multiply defined entities using user arities.
compiler/make_hlds_error.m:
    As above.

compiler/add_class.m:
compiler/add_mode.m:
compiler/add_pred.m:
compiler/add_type.m:
    Conform to the change above.
2022-02-24 01:38:30 +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
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
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
346172849c Use standard length comment lines. 2022-01-10 08:59:08 +11:00
Zoltan Somogyi
d64961d79d Use checked types/insts/modes in parse_tree_module_src.
This means that we can do the exact same checks (and, if needed, generate
the exact same error messages) when generating interface files as when
generating target language code.

This should also allow us to simplify the process of adding type, inst
and mode definitions to the HLDS.

compiler/prog_item.m:
    As above.

    Delete unused function.

compiler/error_util.m:
    Add mechanisms that allow us to distinguish (a) error specs that represent
    a type, inst or mode name definition being invalid, from (b) other error
    specs.

compiler/check_type_inst_mode_defns.m:
    Improve the error messages we generate, in several ways.

    First, for each message, specify a real severity. When the messages
    could be seen only when generating interface files, making them all
    warnings was fine and preserved old behavior, but since soon these
    will be the only place for these checks, we need to call errors errors.

    Second, specify, in the phase, which errors represent a invalid type,
    inst or mode definition, and which don't.

    Third, improve the wording of messages. In some places, do this by
    being clearer about the distinction between declarations and definitions.
    In others, do it by including more information in the message. In yet
    others, do it by recovering some kinds of mistakes (mostly items being
    in the wrong section) enough to avoid avalanche errors.

    Fourth, fix a bug. If a type ctor has an exported *declaration*,
    then it is ok for any foreign type definitions for that type_ctor
    being in the implementation section, but if the type_ctor has an
    exported Mercury *definition*, then any foreign_type definitions
    must be in the interface section as well. The code that handled
    both these situations did not enforce that.

    Fifth, fix another bug: do not include foreign type definitions
    in the source definitions of a type_ctor twice, once as a "du" (sic)
    definition, and once as itself.

compiler/convert_parse_tree.m:
    Check type, inst and mode definitions in raw_compilation_units
    when creating parse_tree_module_srcs.

compiler/comp_unit_interface.m:
    Make the code constructing interface files work from the checked maps
    in parse_tree_module_srcs.

compiler/make_hlds_passes.m:
    Set the flags that say we have found invalid type, inst or mode definitions
    from the error specs constructed during the creation of the checked
    type, inst and mode maps.

compiler/add_type.m:
    Comment out an error message for a condition that will be detected and
    reported by check_type_inst_mode_defns.m.

compiler/make_hlds_separate_items.m:
    For now, turn checked maps of type, inst and mode definitions
    back to item lists for addition to the HLDS. Adding whole checked
    definitions to the HLDS will be done by a future change.

compiler/make_hlds_error.m:
    Fix misleading indentation in an error message.

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

    Generate output whose indentation does not depend on tab settings.

compiler/check_raw_comp_unit.m:
compiler/equiv_type.m:
compiler/get_dependencies.m:
compiler/grab_modules.m:
compiler/module_qual.collect_mq_info.m:
compiler/module_qual.qualify_items.m:
    Conform to the changes above.

compiler/parse_type_defn.m:
    Fix misleading error message for ":- type <name> = <type>".

tests/debugger/foreign_type.{m,exp}:
    Delete a redundant type declaration to avoid a warning, and update
    the .exp file to expect the new line numbers.

tests/invalid/any_mode.err_exp:
tests/invalid/bug436.err_exp:
tests/invalid/bug476.err_exp:
tests/invalid/exported_foreign_enum.err_exp:
tests/invalid/fe_unmapped_nonverbose.err_exp:
tests/invalid/fe_unmapped_verbose.err_exp:
tests/invalid/foreign_enum_invalid.err_exp:
tests/invalid/foreign_solver_type.err_exp:
tests/invalid/foreign_type_visibility.err_exp:
tests/invalid/pragma_qual_error.err_exp:
tests/invalid/repeated_field_name.err_exp:
tests/invalid/subtype_foreign.err_exp:
tests/invalid/type_with_no_defn.err_exp:
tests/invalid/types2.err_exp:
tests/invalid/user_field_access_decl_conflict.err_exp:
tests/invalid_nodepend/bad_foreign_type.err_exp:
tests/invalid_nodepend/bigtest.err_exp:
tests/invalid_nodepend/invalid_typeclass.err_exp:
tests/invalid_nodepend/types.err_exp:
tests/invalid_nodepend/uu_type.err_exp:
tests/invalid_nodepend/where_abstract_enum.err_exp:
    Expect the new error messages.

tests/invalid/abstract_solver_type.{m,err_exp}:
tests/warnings/abstract_solver_type.{m,exp}:
    Move the abstract_solver_type test case from invalid to warnings, because
    this diff changes its only error to be only a warning.

tests/invalid/Mmakefile
2021-10-16 17:37:36 +11:00
Zoltan Somogyi
d2f6f032ea Improve diagnostics for pragmas without preds/funcs.
compiler/make_hlds_error.m:
    When a pragma is supposed to specify a predicate or a function,
    but the name/arity lookup fails, include in the diagnostic
    whether the lookup was a predicate or a function, if the pragma
    specified one or the other.

compiler/add_pragma.m:
    Provide the information make_hlds_error.m needs for the above.

tests/invalid/bad_pragma.{m,err_exp}:
    Extend this existing test case with a test of this functionality.

tests/invalid/require_tailrec_invalid.err_exp:
    Update the expected output in the affected situation.
2021-06-16 17:23:04 +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
ab8c2771f7 Move towards generating .opt/.trans_opt files via items.
compiler/prog_item.m:
    Add types for representing .opt and .trans_opt files that specify
    exactly what kinds of items may appear in them.

    Provide a mechanism for representing just the kinds of pragmas
    that we may want to put into .opt files to represent a predicate marker.

    To make the above possible, generalize the item_pragma_info type.

    Do not store the "maybe attributes" field in all pragmas; store it
    in just the one pragma for which it had pragma-specific code (which code
    is dubious anyway). Its only use is to suppress error messages about
    incorrect pragmas if that pragma was created by the compiler, on the
    theory that the user cannot do anything about any such error messages.
    However, if such errors are never reported to anyone, then they won't
    be fixed. I think it is better to allow such problems to be discovered,
    even if they cause a bit of annoyance to the discoverer. The default
    content of the field as set by the parser, item_origin_user, can be
    misleading anway; it is correct when the pragma is read in from a .m file
    or from a .int* file, but it is wrong when read in from a .*opt file,
    since the contents of those are decided by the compiler.

    Store a varset and tvarset in structure sharing and reuse pragmas,
    since without this, one cannot print them out properly.

compiler/intermod.m:
    Change the predicates that write out .opt and .trans_opt files
    to return as large a fraction of the parse trees of those files
    as possible, as a step towards generating those files not directly,
    but by building and then writing out those parse trees. For now,
    we cannot do this fully for .opt files, because for a few item kinds,
    it is far from obvious how to represent as a item what we write out.

    Leave the opening and closing of the file streams for writing out
    .opt and .trans_opt files to our caller, because for .opt files,
    this allows us to avoid having to open the file *twice*.

    Put the output of result-of-analysis pragmas into a standard order.

    Factor out as common code the process for deciding what should go into
    .opt files.

    Give a field of the intermod_info structure a more precise name.

compiler/mercury_compile_front_end.m:
    Hold the stream of the .opt file open between the two different pieces
    of code that write out the two different parts of .opt files.

    If --experiment5 is set, write out the parse tree of the .opt file
    to the .optx file, to enable comparison with the .opt file.

compiler/mercury_compile_middle_passes.m:
    If --experiment5 is set, write out the parse tree of the .trans_opt file
    to the .trans_optx file, to enable comparison with the .trans_opt file.

    Reset a memo table for structure_{sharing,reuse}.analysis.

compiler/structure_reuse.analysis.m:
compiler/structure_sharing.analysis.m:
    Don't take an I/O state pair as arguments, since we needed them *only*
    for that reset, and for progress messages.

    Give the main predicates more descriptive names.

compiler/trailing_analysis.m:
    Give the main predicate a more descriptive names.

compiler/closure_analysis.m:
    Don't take an I/O state pair as arguments, since we needed them *only*
    for progress messages.

compiler/add_pragma.m:
    Don't ignore an error, since one of the other changes in this diff
    could have fixed its cause.

compiler/convert_interface.m:
    Export utility functions needed by code added by this diff.

ompiler/lp_rational.m:
    Tighten the inst of an output argument for use by intermod.m.

    Bring programming style up to date.

compiler/parse_pragma.m:
    Don't put a maybe attributes field into item_pragma_infos.

    Include the varset in structure sharing and reuse pragmas.

    Use simplest_spec where possible.

compiler/parse_tree_out.m:
    Add predicates for writing out the new parse trees of .opt and
    .trans_opt files.

compiler/parse_tree_out_pragma.m:
    Add predicates needed by the new code in parse_tree_out.m.

compiler/add_mutable_aux_preds.m:
compiler/canonicalize_interface.m:
compiler/comp_unit_interface.m:
compiler/equiv_type.m:
compiler/get_dependencies.m:
compiler/grab_modules.m:
compiler/item_util.m:
compiler/make_hlds_error.m:
compiler/make_hlds_passes.m:
compiler/make_hlds_separate_items.m:
compiler/module_qual.qualify_items.m:
compiler/prog_item_stats.m:
compiler/recompilation.version.m:
    Conform to the changes above.
2019-10-30 10:43:39 +11:00
Zoltan Somogyi
ee6fde3eb6 Delete an unneeded type synonym. 2019-10-28 05:06:15 +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
0f6941447e Use simplest_spec and simplest_msg where appropriate. 2019-10-15 21:48:09 +11:00
Zoltan Somogyi
cb5a1d5d6e Parse interface files via bespoke representations.
We used to read all kinds of interface files (.int0, .int, .int2 and .int3)
into the same representation, parse_tree_int. This diff makes the first step
towards returning the contents of each kind of interface file in its own
bespoke parse tree type, parse_tree_intN for N in {0,1,2,3}.

compiler/parse_module.m:
    Read in the contents of interface files using a cut-down grammar.
    The main changes are:

    - the file must start with a ":- module" declaration;
    - the start of each section must be an explicit section marker;
    - there can be at most two sections, the first an interface section
      and the second an implementation section, in that order,
      either (or both) of which can be missing;
    - version number maps are expected to be *before* the first section;
    - there cannot be any submodules;
    - there cannot be any source_file pragmas anywhere.

    Each of these changes enforces an invariant that is observed by the code
    constructing and writing out the automatically generated interface files.
    The change makes many invalid interface file contents unrepresentable.

    Add predicates for reading each kind interface file to its own
    bespoke parse tree type. These new predicates are not yet used.

    Change the generic predicate for reading in interface files
    to convert the generic parse_tree_int it generates to the given interface
    file's own specific parse tree type, and back. This *should* be an
    identity operation, but it generates an error message whenever it finds
    an entity of a kind that shouldn't be there. Print these messages
    unless inhibited by an option.

    This back-and-forth is intended to be temporary. Once we have sufficient
    experience with the system to be confident it works, i.e. it does not
    miscompile anything and never generates any of these diagnostics,
    we should be able to switch to using the kind-specific parse tree types
    exclusively.

compiler/options.m:
    Add that option, halt-at-invalid-interface, for now, enabled by default.
    We should be able to delete the option, making its effects permanent,
    when we make the switch mentioned above.

compiler/prog_item.m:
    Modify the representation of import_module and use_module declarations
    in .int0 files a bit to match their representations in other kinds of
    interface files.

    Add predicates to convert a parse_tree_int to each parse_tree_intN
    for N in {0,1,2,3}, generating error messages if they contain
    any kind of entity that they shouldn't contain.

    Add functions for describing such entities in the error messages.

    Add some other auxiliary functions, and field names, needed by
    the rest of this change.

compiler/file_kind.m:
    Replace ifk_int with ifk_int1, because we consistently use numeric
    suffixes after interface file kinds everywhere else. (Partly this is
    to disambiguate "int" as short for "interface file", not for
    "interface section of a module".

compiler/parse_types.m:
    Provide a mechanism to describe all entities read in during parsing,
    not just those that end up in parse trees, for use in error messages
    in parse_module.m.

compiler/comp_unit_interface.m:
compiler/deps_map.m:
compiler/grab_modules.m:
compiler/make_hlds_error.m:
compiler/module_qual.qual_errors.m:
    Conform to the changes above.
2019-09-05 11:49:17 +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
214ec425be Make some error messages order-independent.
The old code in modules.m that was recently delete preserved the order
of the items in the source code. The new code that replaced it groups
all the items in a section together. If the source code follows any
pattern other than "one interface section, one implementation section",
then this can change the relative order of two items.

Previously we assumed that items are added to the HLDS in order of their
occurrence in the source code. This diff eliminates that assumption
when we generate error messages that refer to two or more items.

compiler/add_class.m:
    Eliminate this adding-items-by-source-context-order assumption
    when diagnosing duplicate instance declarations.

compiler/add_type.m:
    Eliminate this adding-items-by-source-context-order assumption
    when diagnosing duplicate type declarations and definitions
    (both Mercury types and foreign types).

compiler/make_hlds_error.m:
    Eliminate this adding-items-by-source-context-order assumption
    when diagnosing duplicate declarations of many different kinds
    of items.

compiler/style_checks.m:
    Eliminate this adding-items-by-source-context-order assumption
    when diagnosing non-adjacent argument type and mode declarations
    for the same predicate or function.

compiler/termination.m:
    Eliminate this adding-items-by-source-context-order assumption
    when diagnosing inconsistent termination assertions
    for mutually recursive procedures. Simplify the code
    that generates the error messages doing this.

tests/invalid/bug476.err_exp:
    Expect an error message that uses the phrase
    "previous definition" correctly.
2019-04-24 22:36:02 +10:00
Zoltan Somogyi
e08b8505e9 Import the parents of *all* imported modules. 2019-03-29 12:56:35 +11:00
Zoltan Somogyi
4aed1a57e4 Print an arg type list diff for arg lists with wrong arity.
When a user writes a clause for a predicate (or function) that does not exist
with that arity, but does exist with one or more other arities, report not
just the list of the other arity/arities, but, for each such other arity,
a diff between the declared arg types and the inferred arg types.

After this diff, we generate output like this:

bad_pred_arity.m:027: Error: clause for predicate `bad_pred_arity.p'/4
bad_pred_arity.m:027:   without corresponding `:- pred' declaration.
bad_pred_arity.m:027:   However, predicates of that name do exist with arities
bad_pred_arity.m:027:   3 and 5.
bad_pred_arity.m:027: Inferred :- pred p(int, string, int, string).
bad_pred_arity.m:027:   The argument list difference from the arity 3 version
bad_pred_arity.m:027:   is
bad_pred_arity.m:027:     pred(
bad_pred_arity.m:027:         int,
bad_pred_arity.m:027:   +     string,
bad_pred_arity.m:027:         int,
bad_pred_arity.m:027:         string
bad_pred_arity.m:027:     )
bad_pred_arity.m:027:   The argument list difference from the arity 5 version
bad_pred_arity.m:027:   is
bad_pred_arity.m:027:     pred(
bad_pred_arity.m:027:         int,
bad_pred_arity.m:027:   -     float,
bad_pred_arity.m:027:         string,
bad_pred_arity.m:027:         int,
bad_pred_arity.m:027:         string
bad_pred_arity.m:027:     )

compiler/typecheck_errors.m:
    Generate the diff part of the message above.

compiler/typecheck.m:
    Invoke typecheck_errors.m when relevant.

compiler/error_util.m:
    When comparing two error_specs, switch from a two-level comparison
    (first the contexts of error_msgs, then everything else) to three levels
    first the contexts of error_msgs, then their error_msg_components,
    then everything else). This is needed to allow the error message from
    make_hlds_error.m (which reports the error and mentions the arities
    with which the named predicate or function does exist) come out before
    the informational message from typecheck.m that prints the inferred
    arg types and their differences from the other arities. (With the old
    comparison, the difference in severity would trump the invisible order
    components that this diff includes in both specs to force the desire
    order.)

    Base the code comparing error_specs on the code for comparing error_msgs.
    Move the two previously separate pieces code for those tasks next to each
    other.

compiler/make_hlds_error.m:
    Add the invisble ordering component.

    When we see clauses with two or more wrong arities for a given predicate
    or function, don't list the automatically created pred declaration
    for an *earlier* wrong-arity clause as a real declaration whose arity
    is to be listed in the error messages we generate for *later* wrong-arity
    clauses.

    Add some documentation.

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

library/edit_seq.m:
    A new module for computing diffs.

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

tests/hard_coded/edit_seq_test.{m,exp}:
    A new test case for the diff algorithm.

tests/invalid/bad_pred_arity.{m,err_exp}:
    A new test case for the new error message.

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

tests/invalid/bigtest.err_exp:
tests/invalid/bug197.err_exp:
tests/invalid/bug278.err_exp:
tests/invalid/errors2.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_main.err_exp:
tests/invalid/invalid_octal_literal.err_exp:
tests/invalid/multimode_dcg.err_exp:
tests/invalid/multisoln_func.err_exp:
tests/invalid/null_char.err_exp:
tests/invalid/state_vars_test3.err_exp:
tests/invalid/try_detism.err_exp2:
tests/invalid/typeclass_test_5.err_exp:
tests/invalid/typeclass_test_8.err_exp:
tests/invalid/unsatisfiable_constraint.err_exp:
tests/invalid_purity/impure_func_t3.err_exp:
    Update these files to expect error messages in the new order.

samples/diff/*.m:
    Fix comments, mostly by moving them to where our programming style
    wants them.
2019-01-03 08:57:20 +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
68f0bbf83a Improve error messages about missing predicates.
compiler/make_hlds_error.m:
    When printing an error message about a predicate or function with
    a given name and arity not being found, print the arities for which
    there *is* a predicate or function with that name.

compiler/hlds_error_util.m:
    Provide utility predicates to find the arities with which a name exists.

compiler/typecheck_errors.m:
    Delete the code that is now one of the utility predicates in
    hlds_error_util.m.

compiler/add_foreign_proc.m:
compiler/add_pragma.m:
compiler/add_pragma_type_spec.m:
    When reporting that a foreign_proc or pragma specifies a nonexistent
    predicate or function, tell make_hlds_error.m about the arities
    that the programmer may have meant to put next to the pred or func name.

    When generating error messages about something defined in the current
    module, don't module qualify its name, since the message is unambiguous
    without, and its presence is just clutter for readers.

    In add_pragma.m, when printing an error message about the pragma being
    added being incompatible with previous pragmas, specify their kinds.

compiler/hlds_pred.m:
    Export the fact that the pred_markers type is implemented as a set.
    In more than 20 years, we have never exploited the fact that this type
    was abstract, and I don't think we would in the next 20 :-) The export
    simplifies new code in add_pragma.m.

compiler/hlds_out_pred.m:
    Add a comment reminding future updaters of some code of a requirement
    placed on it by new code in add_pragma.m.

tests/invalid/bad_consider_used.err_exp:
tests/invalid/inline_conflict.err_exp:
tests/invalid/require_tailrec_invalid.err_exp:
tests/invalid/type_spec.err_exp:
tests/invalid_purity/purity_nonsense2.err_exp:
    Expect error messages with the changes listed above.
2017-09-22 05:04:34 +10:00
Zoltan Somogyi
9e285e2b9d Generate better messages for bad inst definitions.
compiler/inst_check.m:
    When an inst for a named type has function symbols that don't appear
    in that type, print not just the incorrect function symbols, but also
    the function symbols that are "near misses", e.g. if error is in
    giving a function symbol the wrong arity.

    Use standard error_util.m functionality to format cons_ids in error
    messages.

compiler/error_util.m:
    Generalize two predicates to enable the error messages we now generate.

compiler/add_foreign_enum.m:
compiler/add_mode.m:
compiler/add_pragma.m:
compiler/hlds_error_util.m:
compiler/make_hlds_error.m:
compiler/module_qual.qual_errors.m:
compiler/modules.m:
compiler/parse_inst_mode_name.m:
compiler/parse_item.m:
compiler/recompilation.check.m:
compiler/typecheck_errors.m:
    Conform to the change in error_util.m.

tests/invalid/bad_inst_for_type.{m,err_exp}:
    Extend this test case with tests of the new functionality.
2017-08-06 23:13:52 +02:00
Zoltan Somogyi
c88a777501 Delete some dead predicates.
compiler/*.m:
    Delete dead predicates that don't look likely to be used in the future
    in their current form.

    For dead predicates that may be needed in the future, shut up warnings
    about them by adding a consider_used pragma for them.

    In intermod.m, delete two unused fields in a structure.
2017-07-11 02:53:35 +02:00
Zoltan Somogyi
ed1010111c Simplify the code adding types a bit.
compiler/make_hlds_passes.m:
    Get module_add_type_defn to set !:FoundInvalidType when it finds an error,
    instead of this module assuming that every error_spec it returns is
    for an actual error. (It could be for a warning.)

    Pass module_add_type_defn's input parameters in a larger, more cohesive
    package.

compiler/make_hlds_error.m:
    Delete a predicate argument that all its callers always set to the same
    value.

    Give several predicates better names.

compiler/add_type.m:
    Make the changes expected by make_hlds_passes.m.

    Don't look for abstract type declarations after we have seen concrete
    definitions. Since we now add all abstract type declarations
    before any concrete definitions, this can never happen.

    Conform to the change to make_hlds_error.m.

compiler/add_class.m:
compiler/add_foreign_proc.m:
compiler/add_mode.m:
compiler/add_pragma.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
    Conform to the change to make_hlds_error.m.
2017-06-23 00:56:49 +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
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
cc9912faa8 Don't import anything in packages.
Packages are modules whose only job is to serve as a container for submodules.
Modules like top_level.m, hlds.m, parse_tree.m and ll_backend.m are packages
in this (informal) sense.

Besides the include_module declarations for their submodules, most of the
packages in the compiler used to import some modules, mostly other packages
whose component modules their submodules may need. For example, ll_backend.m
used to import parse_tree.m. This meant that modules in the ll_backend package
did not have to import parse_tree.m before importing modules in the parse_tree
package.

However, this had a price. When we add a new module to the parse_tree package,
parse_tree.int would change, and this would require the recompilation of ALL
the modules in the ll_backend package, even the ones that did NOT import ANY
of the modules in the parse_tree package.

This happened even at one remove. Pretty much all modules in every one
of the backend have to import one or more modules in the hlds package,
and they therefore have import hlds.m. Since hlds.m imported transform_hlds.m,
any addition of a new middle pass to the transform_hlds package required
the recompilation of all backend modules, even in the usual case of the two
having nothing to do with each other.

This diff removes all import_module declarations from the packages,
and replaces them with import_module declarations in the modules that need
them. This includes only a SUBSET of their child modules and of the non-child
modules that import them.
2015-11-13 15:03:20 +11:00
Zoltan Somogyi
1db28e27d8 Convert (C->T;E) to (if C then T else E). 2015-10-18 08:59:10 +11:00
Zoltan Somogyi
753fe25c90 Put the later parts of .*opt files in a standard order.
compiler/intermod.m:
    We used to put predicate declarations and definitions into .opt files
    in order of pred_id. Since pred_ids are allocated sequentially, this
    meant that the order of the pragmas in .*opt files recording analysis
    results was determined by the order of the predicate declarations
    in the .m file, and if this changes, everything that depends on the
    .opt file has to be recompiled. Change this to put the pragmas into
    an order based on the predicates' names, arities, and pred_or_func flag.

    Precede each block of analysis results (one block per pragma type)
    with a blank line, to make .*opt files a bit easier to read by revealing
    their structure.

    When printing analysis results for all the procedures of a predicate,
    don't get a list of proc_ids and then look them up one by one; just
    iterated over all the proc_infos in the proc_table.

    Rename some predicates to make their names fit into the naming scheme
    used in the rest of the module.

compiler/hlds_module.m:
compiler/hlds_pred.m:
    The results of the exception, trailing and mm_tabling analyses
    used to be stored in the module_info as maps from pred_proc_ids
    to the results about the procedure. Change this to store them
    in the proc_info of the procedure, since any code that looks up
    the results of an analysis typically also wants to look up other
    information in the proc_info as well. (intermod.m certainly does.)

    The results of the termination, structure sharing and structure reuse
    analysis were already stored in the proc_info.

compiler/add_pragma.m:
    When reading in exceptions, trailing and mm_tabling pragmas,
    add their information to the named procedure's proc_info,
    not to a map in the module_info.

compiler/exception_analysis.m:
compiler/tabling_analysis.m:
compiler/trailing_analysis.m:
    Put analysis results into procedures' proc_infos, not into a map
    in the module_info, and if need be, look it up there as well.

compiler/goal_form.m:
    Look up the results of exception_analysis in procedures' proc_infos,
    not in a map in the module_info.

compiler/lco.m:
    Work around a bug in lco.m itself exposed by the move of analysis
    results to proc_infos. When lco.m duplicates the proc_info of a procedure
    that it optimizes, it now duplicates its analysis results as well.
    The duplication is correct in a sense, since any results of the exception,
    trailing and mm_tabling analysis that hold for the original procedure
    have to hold for the duplicate copy as well, but interestingly, this extra
    precision causes simplify to believe that the call from the original
    procedure to duplicated procedure is dead code that can be eliminated,
    since it is det and appears to have no outputs. In fact, it does have
    outputs, but it returns those outputs via impure calls to store_at_ref.
    While the call to store_at_ref in the duplicated procedure is marked
    as impure, the call to the duplicate procedure in the original procedure
    is NOT (yet) so marked.

compiler/parse_tree_out_pred_decl.m:
    When printing parts of predicate declarations, e.g. as parts of pragmas
    that record analysis results, don't take as an argument a context that
    will never be used.

compiler/add_clause.m:
compiler/dependency_graph.m:
compiler/hlds_out_pred.m:
compiler/make_hlds_error.m:
compiler/mode_errors.m:
compiler/parse_tree_out.m:
compiler/parse_tree_out_pragma.m:
compiler/typecheck.m:
    Conform to the changes in parse_tree_out_pred_decl.m above.

tests/term/*.trans_opt_exp:
    Expect the same termination analysis results as before, just in
    predicate name order, and with a blank line before each block.
2015-09-16 10:45:05 +10:00
Zoltan Somogyi
656493dfdf Use separate types for the status of different entity kinds.
We used the old import_status type to represent the status of six different
kinds of entities:

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

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

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

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

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

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

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

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

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

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

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

    Update the predicates that test predicate statuses accordingly.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

compiler/accumulator.m:
compiler/add_clause.m:
compiler/add_foreign_enum.m:
compiler/add_foreign_proc.m:
compiler/add_mode.m:
compiler/add_mutable_aux_preds.m:
compiler/add_pragma.m:
compiler/add_pragma_tabling.m:
compiler/add_pragma_type_spec.m:
compiler/add_pred.m:
compiler/add_solver.m:
compiler/add_type.m:
compiler/base_typeclass_info.m:
compiler/ctgc.util.m:
compiler/dead_proc_elim.m:
compiler/dep_par_conj.m:
compiler/dependency_graph.m:
compiler/det_report.m:
compiler/elds_to_erlang.m:
compiler/equiv_type_hlds.m:
compiler/erl_code_gen.m:
compiler/export.m:
compiler/float_regs.m:
compiler/higher_order.m:
compiler/hlds_code_util.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/inst_check.m:
compiler/lambda.m:
compiler/lco.m:
compiler/make_hlds.m:
compiler/make_hlds_warn.m:
compiler/make_tags.m:
compiler/ml_proc_gen.m:
compiler/ml_type_gen.m:
compiler/mode_errors.m:
compiler/oisu_check.m:
compiler/par_loop_control.m:
compiler/polymorphism.m:
compiler/post_term_analysis.m:
compiler/post_typecheck.m:
compiler/prop_mode_constraints.m:
compiler/recompilation.usage.m:
compiler/simplify_proc.m:
compiler/smm_common.m:
compiler/special_pred.m:
compiler/ssdebug.m:
compiler/status.m:
compiler/stm_expand.m:
compiler/structure_reuse.analysis.m:
compiler/structure_reuse.direct.m:
compiler/structure_reuse.indirect.m:
compiler/structure_reuse.versions.m:
compiler/structure_sharing.analysis.m:
compiler/structure_sharing.domain.m:
compiler/superhomogeneous.m:
compiler/table_gen.m:
compiler/term_constr_initial.m:
compiler/term_constr_main.m:
compiler/termination.m:
compiler/trace_params.m:
compiler/type_class_info.m:
compiler/type_constraints.m:
compiler/type_ctor_info.m:
compiler/typecheck.m:
compiler/typecheck_info.m:
compiler/typeclasses.m:
compiler/unify_proc.m:
compiler/untupling.m:
compiler/unused_args.m:
compiler/unused_imports.m:
compiler/xml_documentation.m:
    Conform to the changes above.
2015-09-12 09:07:45 +10:00
Zoltan Somogyi
bbb2535eb5 Break up mercury_to_mercury.m.
With almost 6000 lines, mercury_to_mercury.m was one of the biggest modules
of compiler, but it was far from cohesive. This diff carves seven new modules
out of it, each of which is much more cohesive. The stuff remaining in
mercury_to_mercury.m is still not as cohesive as one would like, but it is
now small enough that moving its individually-cohesive parts into modules
of their own would be overkill.

Three consequences of the old mercury_to_mercury.m's lack of cohesion
were that

- the order of predicate declarations often did not match the order of
  their implementation;
- related predicates were not grouped together;
- even when they were grouped together, the order of those groups
  was often random.

This diff fixes all three of these problems for all eight successor modules
of mercury_to_mercury.m: the seven new modules, and the new
mercury_to_mercury.m itself.

In some cases, this diff adds or improves the documentation of the predicates
in mercury_to_mercury.m's successor modules. In some other cases, it just
documents the lack of documentation :-(. In yet other cases, it removes
"documentation" that says nothing that isn't obvious from the predicate's name.

There are some algorithmic changes, but they are all trivial.

compiler/parse_tree_out.m:
    New module containing the code to print out the top levels of parse trees,
    including most sorts of items.

compiler/parse_tree_out_clause.m:
    New module containing the code to print out clauses and goals.

compiler/parse_tree_out_pragma.m:
    New module containing the code to print out pragmas.

compiler/parse_tree_out_pred_decl.m:
    New module containing the code to print out predicate, function and
    mode declarations. It is separate from parse_tree_out.m because a
    significant number of compiler modules need only its functionality,
    and not parse_tree_out.m's functionality.

compiler/parse_tree_out_inst.m:
    New module containing the code to print out insts and modes.

compiler/parse_tree_out_term.m:
    New module containing the code to print out variables and terms.

compiler/parse_tree_out_info.m:
    New module containing the infrastructure of both mercury_to_mercury.m
    and the other new modules.

compiler/parse_tree.m:
    Include the new modules.

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

compiler/Mercury.options:
    Transfer an option from mercury_to_mercury.m to the successor module
    that needs it.

compiler/*.m:
    Import one of the new modules either as well as, or instead of,
    mercury_to_mercury.m. In most cases, we need to import only one
    or two of mercury_to_mercury.m's successor modules; nowhere do we
    need to import all eight.

    Clean up some code in termination.m around a call to one of the
    new modules.

tools/speedtest:
    Replace mercury_to_mercury.m on the list of the ten largest modules
    of the compiler.
2015-09-06 21:01:11 +10:00
Zoltan Somogyi
850d461c40 Make `:- external' a pragma inside the compiler and out.
We used to have only the first of these three forms, we now have all three:

:- external(low_level_backend, a/2).
    % declared pred a/2 and func a/2 to be external on llds
:- pragma external_pred(a/2, [low_level_backend]).
    % declared pred a/2 (and NOT func a/2) to be external on llds
:- pragma external_func(a/2, [low_level_backend]).
    % declared func a/2 (and NOT pred a/2) to be external on llds

The new forms allow for more precise control of what is declared to be
external. The difference in syntax (the options coming after the name,
and the options being in a list, even though this pragma allows only
one option at present) are to fit in with the style of the other pragmas.

Of course, the backend does not have to be specified, so these are
also allowed:

:- pragma external_pred(a/2).
:- pragma external_func(a/2, []).

Using `:- external' declarations is for implementors only, since using it
requires writing target language code by hand in a way that conforms to all
the compiler's conventions for e.g. symbol naming and parameter passing.
It is not a documented part of Mercury. Therefore the new external_{func,pred}
pragmas are not documented either.

compiler/prog_item.m:
    Change the representation of the `:- external' declaration from being
    a module_defn to being a pragma. Generalize it to allow the new pragmas,
    by allowing the recording of an option pred_or_func indication.

    Add a function that returns a description of a pragma for use as a context
    in error messages. We need this to avoid confusing users by having an
    error message refer to a `:- external' declaration when they wrote e.g.
    `:- pragma external_pred', or vice versa.

compiler/add_pragma.m:
    Move the code for handling external declarations from make_hlds_passes
    (which handles module_defns) to this module (which handles pragmas),
    and update it.

    Execute this code in pass 2, not pass 1, since we need to record
    the "external" flag in the pred_info, and that is created in pass 1.
    (I think this worked in the past ONLY if the declaration of the affected
    predicate or function came textually before the `:- external' declaration.)

compiler/make_hlds_passes.m:
    Remove the code that is now in add_pragma.m (in adapted form).

compiler/prog_io_item.m:
    Change the code for parsing old-style `:- external' declarations to
    generate the new pragma internally.

compiler/prog_io_pragma.m:
    Add code for parsing the new pragmas.

compiler/equiv_type.m:
compiler/item_util.m:
compiler/mercury_to_mercury.m:
compiler/module_imports.m:
compiler/module_qual.m:
compiler/modules.m:
compiler/recompilation.version.m:
compiler/write_module_interface_files.m:
    Conform to the changes above.

compiler/make_hlds_error.m:
    Improve a variable name.

compiler/pred_table.m:
    Improve the documentation of several predicates.

tests/hard_coded/backend_external.m:
    Improve the documetation of this old test case, which tests the
    handling of backend-specific `:- external' declarations.

tests/hard_coded/backend_external_{func,pred}.m:
    Two copies of the old backend_external.m test case, which test the
    handling of backend-specific `:- pragma external_func' and
    `:- pragma external_pred' declarations respectively.

tests/hard_coded/backend_external_func.exp:
tests/hard_coded/backend_external_pred.{exp,exp2}:
    The expected outputs of the new test cases.

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

tests/invalid/type_spec.err_exp:
    Expect an error message for a `:- external' declaration in the interface
    of type_spec.m. Since declaring a procedure to be external is in essence
    a representation of the implementation of that procedure, the previous
    absence of an error message for this implementation detail in the interface
    was a bug.

tests/invalid/external.err_exp:
    We always generated an error for a `:- external' declaration that
    did not specify an arity, but the text of the error message used to say
    "warning", not "error" (even though the severity level was "error").
    Expect the corrected error message.

tests/invalid/not_in_interface.err_exp:
    Expect the updated, more precise form of an error message.

vim/syntax/mercury.vim:
    Add the two new keywords.
2015-07-22 14:58:44 +10:00
Zoltan Somogyi
97e306a434 When reporting undefined procs, point out possible arity errors.
compiler/make_hlds_error.m:
    As above. When printing an error message about a clause for pred p/N
    or func f/N, point out any values of M (M != N) for which p/M or f/M
    *is* defined.

    Take the information about whether the procedure the original error
    is being reported for in the form of a bespoke enum, not a bool.

compiler/prog_data.m:
    Define that bespoke enum type.

compiler/add_class.m:
compiler/add_clause.m:
compiler/add_foreign_proc.m:
compiler/add_pragma_tabling.m:
compiler/add_pred.m:
compiler/make_hlds_passes.m:
    Conform to the changes above.

tests/invalid/bug197.err_exp:
tests/invalid/errors2.err_exp:
    Expect the additional output we now generate.
2015-07-21 09:03:32 +10:00
Zoltan Somogyi
f2043fc9bd Replace the item list with more structured ASTs.
The parts of the compiler that run before the HLDS is constructed used to use
a raw list of items to represent source files (.m), interface files (.int0,
.int3, .int2 and .int) and optimization files (.opt, and .trans_opt).
These lists had structure, but this structure was implicit, not explicit,
and its invariants were never really documented.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

compiler/status.m:
    New module, containing mostly

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

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

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

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

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

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

    Pretty-print type definitions nicely.

    Replace a boolean with a purpose-specific enum.

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

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

    Avoid ambiguities by adding a prefix to field names.

    Add some convenience predicates.

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

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

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

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

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

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

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

    Avoid ambiguities by adding a prefix to field names.

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

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

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

    Add a det version of sym_name_get_module_name.

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

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

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

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

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

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

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

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

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

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

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

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

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

tests/valid/complicated_unify.m:
tests/valid/det_switch.m:
tests/valid/easy_nondet_test.m:
tests/valid/error.m:
tests/valid/func_class.m:
tests/valid/func_int_bug_main.m:
tests/valid/higher_order.m:
tests/valid/higher_order2.m:
tests/valid/implied_mode.m:
tests/valid/indexing.m:
tests/valid/multidet_test.m:
tests/valid/nasty_func_test.m:
tests/valid/semidet_disj.m:
tests/valid/stack_alloc.m:
tests/valid/switches.m:
    Add missing section markers to these modules. They used to follow
    the `:- module' declaration directly with code.
2015-07-21 04:06:52 +10:00
Zoltan Somogyi
05f5ec7d41 Fix a bug that put $typed_insts in .opt files.
compiler/mercury_to_mercury.m:
    Make the predicates that output insts take a parameter that says whether
    we are trying to print valid Mercury code (in which case we strip any
    $typed_inst wrappers around other insts), or as-informative-as-possible
    representations of insts for debugging, in which case we do NOT strip
    those wrappers. When invoked on insts that CANNOT be printed as valid
    Mercury even though valid Mercury is being requested, abort.

    Rationalize the argument order of the involved predicates.

    Move the output_lang type here from hlds_out_util.m to make the above
    possible. Change the flag that governs whether item names are qualified
    or not from a bool to a bespoke enum type. Fix a bug involving that bool.

compiler/hlds_out_mode.m:
    This module also has a predicate that output insts, though it already had
    a valid mercury/debug output flag. If it is asked to print valid Mercury,
    make it strip $typed_inst wrappers, and abort on insts that cannot be
    printed as valid Mercury.

    A better fix would be to eliminate this predicate, and other predicates
    in this module that also duplicate predicates in mercury_to_mercury.m,
    after generalizing the latter as needed, but that would take more time.

compiler/add_clause.m:
compiler/add_mutable_aux_preds.m:
compiler/dep_par_conj.m:
compiler/dependency_graph.m:
compiler/format_call.m:
compiler/goal_expr_to_goal.m:
compiler/hlds_error_util.m:
compiler/hlds_out_goal.m:
compiler/hlds_out_module.m:
compiler/hlds_out_pred.m:
compiler/hlds_out_util.m:
compiler/intermod.m:
compiler/liveness.m:
compiler/make_hlds_error.m:
compiler/mercury_to_mercury.m:
compiler/mode_errors.m:
compiler/passes_aux.m:
compiler/pd_debug.m:
compiler/push_goals_together.m:
compiler/saved_vars.m:
compiler/stack_opt.m:
compiler/structure_reuse.analysis.m:
compiler/structure_sharing.analysis.m:
compiler/term_constr_main.m:
compiler/termination.m:
compiler/unneeded_code.m:
    Conform to the above.

compiler/mode_constraint_robdd.m:
compiler/mode_constraints.m:
    Fix an unrelated problem that ALSO prevented a bootcheck with -O5
    --intermodule-optimization, which is that with these options, several
    predicates in both these modules accumulated enough type ambiguities
    for the type checker to throw up its hands in despair.

    The type checker should NOT be influenced by the additional types, data
    constructors, field names, functions and predicates added by these options
    to their respective tables, but it is. Fixing that bug is future work.
    For now, just reduce the ambiguities to the allowable level, mostly
    by adding module qualifiers, and by converting some function calls to
    predicate calls. (Function calls introduce ambiguities, since the
    typechecker thinks they may be partially applied predicate calls.)
2015-04-02 12:09:42 +11:00
Zoltan Somogyi
4e3af446ef Give some verbose error explanations only once.
compiler/error_util.m:
    Some of the messages we print if --verbose-errors are enabled just explain
    what an always-printed error message means. If a compiler invocation
    reports several instances of an error, the explanation is useful
    only the first time. This diff provides a mechanism for printing
    such verbose messages only once per invocation of write_error_specs.

compiler/*.m:
    Specify verbose_once for verbose error message components which are
    (a) not specific to the specific instance of the error they are generated
    for, and (b) whose usefulness/size ratio is not high enough. Part (b)
    means that it is ok to repeatedly print a single-line reminder,
    but not a 20-line missive that reads like an extract from the
    reference manual.

    In one case, make an error message clearer.

tests/invalid/*.err_exp:
tests/warnings/*.exp:
    Expect the new, slimmed-down output.
2015-02-19 12:38:07 +11:00
Zoltan Somogyi
13b6f03f46 Module qualify end_module declarations.
compiler/*.m:
    Module qualify the end_module declarations. In some cases, add them.

compiler/table_gen.m:
    Remove an unused predicate, and inline another in the only place
    where it is used.

compiler/add_pragma.m:
    Give some predicates more meaningful names.
2014-09-04 00:24:52 +02:00
Zoltan Somogyi
500948d549 Break up mdbcomp/prim_data.m. The new modules have much better cohesion.
mdbcomp/sym_name.m:
    New module, containing the part of the old prim_data.m that
    dealt with sym_names.

mdbcomp/builtin_modules.m:
    New module, containing the part of the old prim_data.m that
    dealt with builtin modules.

mdbcomp/prim_data.m:
    Remove the things that are now in the two new modules.

mdbcomp/mdbcomp.m:
deep_proiler/Mmakefile:
slice/Mmakefile:
    Add the two new modules.

browser/*.m:
compiler/*.m:
deep_proiler/*.m:
mdbcomp/*.m:
slice/*.m:
    Conform to the above changes.
2014-09-02 05:20:23 +02:00
Julien Fischer
6682cc0a44 Improve the wording of some error messages.
Use the word "corresponding" instead of "preceding" in error messages like:

    Error: clause for predicate `foo'/0 without preceding `:- pred'
    declaration.

The language imposes no ordering on declarations so there is no sense in which
the `:- pred' declaration has to precede the clause.  This is doubly true for
`:- typeclass' and `:- instance' declarations, which may also occur in
different source files from each other.

compiler/make_hlds_error.m:
compiler/add_class.m:
	Make the above change.

	Delete a comment regarding this issue.

tests/invalid/*/.err_exp:
	Update expected error outputs.
2014-08-25 15:02:37 +10:00
Julien Fischer
90b2d233c0 Improve more error messages.
Make consistency improvements to error messages concerning initialise, finalise
and mutable declarations.

compiler/make_hlds_error.m:
	Pass a list of format_components to error_if_exported/5 and
	error_is_exported/4 as the item description instead of a string.

compiler/add_pragma.m:
compiler/make_hlds_passes.m:
	Conform to the above change.

compiler/modes.m:
	Use the pragma_decl/1 format component in a couple of spots.

tests/invalid/bad_finalise_decl.err_exp:
tests/invalid/bad_initialise_decl.err_exp:
tests/invalid/bad_mutable.err_exp:
tests/invalid/imported_mode.err_exp:
tests/invalid/not_in_interface.err_exp:
tests/invalid/uniq_mutable.err_exp:
	Conform to the above changes.
2014-07-31 09:02:07 +10:00
Julien Fischer
d5cdd701b1 Further consistency improvements for error and warning messages.
The two main changes in this commit are:

(1) Use the error_util library's decl/1 and pramga_decl/1 format components in more
places.

(2) Quote type variables that appear in error messages.

compiler/error_util.m:
	Add a version of list_to_pieces/1 that places each of the strings in
	the input list in single quotes.

compiler/prog_io_type_defn.m:
	Quote type variables names in error messages.

compiler/add_class.m:
compiler/add_pragma.m:
compiler/add_pred.m:
compiler/check_typeclass.m:
compiler/make_hlds_error.m:
compiler/post_typecheck.m:
compiler/prog_io.m:
	Use the error_util library's decl/1 and pragma_decl/1 format components
	in more places.

compiler/mode_errors.m:
	Quote program variables and insts in some error messages.

compiler/post_term_analysis.m:
	Format a type ctor and arity in an error message properly.

tests/invalid/*.err_exp:
tests/warnings/*.exp:
	Conform to the above changes.
2014-07-30 23:09:39 +10:00
Julien Fischer
12503b84f3 Do not hardcode quoting style in error messages.
Replace spots in error message specs. where single quotes are hardcoded as `' with
the error_util library's quote/1 constructor.

Fix minor issues with some error messages and add a couple of XXX comments
about some others.

compiler/accumulator.m:
compiler/add_clause.m:
compiler/add_pragma.m:
compiler/add_pred.m:
compiler/add_type.m:
compiler/det_analysis.m:
compiler/det_report.m:
compiler/goal_expr_to_goal.m:
compiler/make_hlds_error.m:
compiler/mercury_compile.m:
compiler/mode_errors.m:
compiler/modes.m:
compiler/modules.m:
compiler/options_file.m:
compiler/post_typecheck.m:
compiler/prog_io.m:
compiler/prog_io_pragma.m:
compiler/simplify_goal.m:
compiler/simplify_proc.m:
compiler/term_constr_errors.m:
compiler/term_errors.m:
compiler/termination.m:
compiler/typecheck.m:
compiler/typecheck_errors.m:
	As above.

tests/invalid/errors.err_exp:
tests/invalid/missing_det_decl.err_exp:
tests/invalid/no_exports.err_exp:
tests/invalid/predmode.err_exp:
tests/invalid/undef_type.err_exp:
	Conform to the above changes.
2014-07-28 12:09:44 +10:00
Zoltan Somogyi
66eb371f4d Add preliminary support for a new pragma that will be needed to implement
Estimated hours taken: 16
Branches: main

Add preliminary support for a new pragma that will be needed to implement
order-independent state update (oisu). The pragma will look like this:

:- pragma oisu(global_data/0, [
	creators([global_data_init/3]),
	mutators([global_data_add_new_proc_var/4,
		global_data_add_new_proc_layout/4,
		...]),
	destructors([])
]).

compiler/prog_item.m:
	Add a representation for oisu pragmas.

	Change the representation of some existing pragmas to represent
	type_ctors as a unit.

	Give the representation of an existing pragma a less ambiguous name.

compiler/prog_data.m:
	Make a type tighter.

compiler/make_hlds_error.m:
	Give some predicates that generate error messages the ability
	to keep some parts of error messages atomic (i.e. unbreakable
	at white space).

compiler/prog_io_pragma.m:
	Add code for parsing oisu pragmas.

	Treat type_ctors in pragmas as unit, not as a name/arity pair.

compiler/add_pragma.m:
compiler/make_hlds_passes.m:
	Make_hlds_passes.m adds items to the HLDS in three passes (this is
	due to dependencies between items). Pragmas are handled in passes
	2 and 3. One pass used to decide what to do for pragmas in
	make_hlds_passes.m, the other pass made that same decision
	in add_pragma.m. We now make the decision in add_pragma.m
	in BOTH passes. This allows add_pragma.m to export many fewer
	predicates, and reduces the coupling between the two modules.

compiler/add_pragma.m:
compiler/prog_data.m:
	Move a generally-useful function from add_pragma.m to prog_data.m.

compiler/add_pragma.m:
	Add preliminary code for handling oisu pragmas to the HLDS. (Since
	the HLDS has not yet been updated to handle oisu pragmas, we don't
	yet update the HLDS when we handle oisu pragmas.)

	Simplify some code.

compiler/prog_io_util.m:
	Rename a predicate to avoid an ambiguity.

compiler/add_clause.m:
compiler/add_pred.m:
compiler/equiv_type.m:
compiler/goal_expr_to_goal.m:
compiler/intermod.m:
compiler/mercury_to_mercury.m:
compiler/module_imports.m:
compiler/module_qual.m:
compiler/modules.m:
compiler/prog_io_mutable.m:
compiler/prog_io_type_defn.m:
compiler/recompilation.check.m:
compiler/recompilation.version.m:
	Conform to the changes above.
2012-09-10 13:33:08 +00:00
Zoltan Somogyi
cc42c8fac5 Switch to using error_util to generate error message during the process of
Estimated hours taken: 40
Branches: main

Switch to using error_util to generate error message during the process of
converting terms to prog_items.

In many predicates, we used to return error messages as a string/term pair,
with the string being the error message and a term, which both provided
the context and was printed after the message. We now return error indications
as lists of error_specs. These include a printout of the relevant term only
if this helps users understand the nature or the location of the error.
To make the printouts easier to understand we print variable names in them
using the applicable varsets. (The old version of the compiler used to print
each error term long after it lost track of the right varset, and thus used
a dummy varset that yielded error messages referring to _1, _2 etc instead
of the variable names used by the programmer.)

Sometimes the callers of some parse predicates prepended other strings
indicating the context of the error in front of the error string.
This diff changes things so that now the caller instead passes a list
of format components describing the context to the predicates that construct
the error_specs.

In some places, simplify the code, e.g. by factoring out common code, and by
inlining some auxiliary predicates (we used to need these auxiliary predicates
for indexing when we executed the compiler using Prolog, but those days are
long past).

Mark with XXXs places where I think the error messages or their contexts
could be improved, and places where the structure of the code could be
improved.

compiler/prog_io_util.m:
	Change the representation of the maybeN types to use error_spec lists.

compiler/prog_io.m:
compiler/prog_io_dcg.m:
compiler/prog_io_goal.m:
compiler/prog_io_pragma.m:
compiler/prog_io_typeclass.m:
compiler/prog_io_util.m:
	Change the way we generate error messages along the lines described
	at the top.

	In several cases, this required adding extra arguments (varsets,
	context descriptions) to predicates for use in error messages.

	Some of these predicates were also used in contexts where the caller
	was interested only in success, and would ignore any error messages.
	In these cases, add a version of the predicate that does not require
	the extra arguments, and which is semidet (to allow the caller to
	avoid a test for ok).

compiler/error_util.m:
	Add a mechanism for changing the case of the next format_component,
	to allow an error message to be appended to a list of format_components
	providing the context that generates good-looking output whether or not
	that context is empty.

	Replace some bools with purpose-specific types.

	Make sort_error_specs internal to the module, since outside modules
	should never need to use it.

	Use cords instead of reversed lists to simplify some parts of the
	internal implementation.

compiler/mercury_to_mercury.m:
	Provide a mechanism to print out terms only if they aren't too big,
	for use in our error messages.

compiler/prog_item.m:
	Delete the message_list type, and note a future improvement.

compiler/prog_out.m:
	Delete the predicates for printing message_lists.

compiler/intermod.m:
compiler/modules.m:
	Change the way we print out error messages along the lines described
	at the top.

compiler/add_clause.m:
compiler/field_access.m:
compiler/recompilation.check.m:
compiler/recompilation.version.m:
compiler/superhomogeneous.m:
	Conform to the changes above by modifying how we generate error
	messages.

compiler/add_class.m:
compiler/add_pragma.m:
compiler/check_typeclass.m:
compiler/common.m:
compiler/make.module_dep_file.m:
compiler/make_hlds_error.m:
compiler/make_hlds_passes.m:
compiler/mercury_compile.m:
compiler/mode_errors.m:
compiler/modes.m:
compiler/options_file.m:
compiler/prog_ctgc.m:
compiler/prog_event.m:
compiler/purity.m:
compiler/trans_opt.m:
compiler/typecheck.m:
	Trivial updates to conform to the changes above.

compiler/prog_data.m:
	Add some field names and access functions for use in the modules above.

library/list.m:
	Add list.contains, which is list.member with the arguments reversed
	to make it possibly to partially apply it.

tests/invalid/bad_finalise_decl.err_exp:
tests/invalid/bad_initialise_decl.err_exp:
tests/invalid/bad_mutable.err_exp:
tests/invalid/bigtest.err_exp:
tests/invalid/conflicting_fs.err_exp:
tests/invalid/constrained_poly_insts.err_exp:
tests/invalid/errors.err_exp:
tests/invalid/func_errors.err_exp:
tests/invalid/fundeps_unbound_in_ctor.err_exp:
tests/invalid/fundeps_vars.err_exp:
tests/invalid/impl_def_literal_syntax.err_exp:
tests/invalid/inst_list_dup.err_exp:
tests/invalid/invalid_typeclass.err_exp:
tests/invalid/kind.err_exp:
tests/invalid/null_char.err_exp:
tests/invalid/pragma_source_file.err_exp:
tests/invalid/predmode.err_exp:
tests/invalid/reserve_tag.err_exp:
tests/invalid/some.err_exp:
tests/invalid/specified.err_exp:
tests/invalid/trace_goal_env.err_exp:
tests/invalid/type_vars.err_exp:
tests/invalid/typeclass_test_1.err_exp:
tests/invalid/typeclass_test_11.err_exp:
tests/invalid/typeclass_test_2.err_exp:
tests/invalid/unbound_type_vars.err_exp:
tests/invalid/unicode1.err_exp:
tests/invalid/unicode2.err_exp:
tests/invalid/uu_type.err_exp:
tests/invalid/vars_in_wrong_places.err_exp:
tests/invalid/with_type.err_exp:
tests/invalid/purity/purity_nonsense2.err_exp:
	Update the expected error messages.
2008-07-16 03:31:03 +00:00
Julien Fischer
b4c3bb1387 Clean up in unused module imports in the Mercury system detected
Estimated hours taken: 3
Branches: main

Clean up in unused module imports in the Mercury system detected
by --warn-unused-imports.

analysis/*.m:
browser/*.m:
deep_profiler/*.m:
compiler/*.m:
library/*.m:
mdbcomp/*.m:
profiler/*.m:
slice/*.m:
	Remove unused module imports.

	Fix some minor departures from our coding standards.

analysis/Mercury.options:
browser/Mercury.options:
deep_profiler/Mercury.options:
compiler/Mercury.options:
library/Mercury.options:
mdbcomp/Mercury.options:
profiler/Mercury.options:
slice/Mercury.options:
	Set --no-warn-unused-imports for those modules that are used as
	packages or otherwise break --warn-unused-imports, e.g. because they
	contain predicates with both foreign and Mercury clauses and some of
	the imports only depend on the latter.
2006-12-01 15:04:40 +00:00