[Bug fortran/99065] New: ASSOCIATE function selector expression "no IMPLICIT type" failure

[Bug fortran/99065] New: ASSOCIATE function selector expression "no IMPLICIT type" failure

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99065

            Bug ID: 99065
           Summary: ASSOCIATE function selector expression "no IMPLICIT
                    type" failure
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pault at gcc dot gnu.org
  Target Milestone: ---

Created attachment 50164
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50164&action=edit
Testcase illustrating the failure

This bug was detected in testing variations of the testcase in PR98897.

The attached fails with:
../pr98897/foo1.f90:9:20:

    9 |       print *, var%i
      |                    1
Error: Symbol ‘var’ at (1) has no IMPLICIT type

If the contained procedures 'foo' and 'bar' are interchanged it compiles and
produces the intended result.

All component references suffer from this problem. Intrinsic types are fixed up
by parse.c(gfc_fixup_sibling_symbols) but there is no simple way to do this for
derived type or class selectors.

Certain operator expressions also suffer from this problem.

It is caused by parsing and matching in gfortran being single pass. This means
that unless the specification of 'bar', in this case, has been obtained, the
type of 'var' cannot be determined and primary.c(gfc_match_varspec) is bound to
return MATCH_NO.

I am looking at either two passes for contained procedures (specification
blocks first, followed by code blocks) or a fixup in gfc_match_varspec that
looks through the derived types for successful matches.

Paul

[Bug fortran/99065] ASSOCIATE function selector expression "no IMPLICIT type" failure

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99065

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-02-13
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
Confirmed since at least GCC7.

[Bug fortran/99065] ASSOCIATE function selector expression "no IMPLICIT type" failure

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99065

Paul Thomas <pault at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #2 from Paul Thomas <pault at gcc dot gnu.org> ---
I actually worked on this one first but have to give the prior credit to Ian
Harvey.

Paul

*** This bug has been marked as a duplicate of bug 89645 ***

[Bug fortran/99065] ASSOCIATE function selector expression "no IMPLICIT type" failure

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99065

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Paul Thomas <pault@gcc.gnu.org>:

https://gcc.gnu.org/g:3fd46d859cda1074125449a4cc680ce59fcebc38

commit r14-9489-g3fd46d859cda1074125449a4cc680ce59fcebc38
Author: Paul Thomas <pault@gcc.gnu.org>
Date:   Fri Mar 15 06:52:59 2024 +0000

    Fortran: Fix class/derived/complex function associate selectors [PR87477]

    2024-03-15  Paul Thomas  <pault@gcc.gnu.org>

    gcc/fortran
            PR fortran/87477
            PR fortran/89645
            PR fortran/99065
            PR fortran/114141
            PR fortran/114280
            * class.cc (gfc_change_class): New function needed for
            associate names, when rank changes or a derived type is
            produced by resolution
            * dump-parse-tree.cc (show_code_node): Make output for SELECT
            TYPE more comprehensible.
            * expr.cc (find_inquiry_ref): Do not simplify expressions of
            an inferred type.
            * gfortran.h : Add 'gfc_association_list' to structure
            'gfc_association_list'. Add prototypes for
            'gfc_find_derived_types', 'gfc_fixup_inferred_type_refs' and
            'gfc_change_class'. Add macro IS_INFERRED_TYPE.
            * match.cc (copy_ts_from_selector_to_associate): Add bolean arg
            'select_type' with default false. If this is a select type name
            and the selector is a inferred type, build the class type and
            apply it to the associate name.
            (build_associate_name): Pass true to 'select_type' in call to
            previous.
            * parse.cc (parse_associate): If the selector is inferred type
            the associate name is too. Make sure that function selector
            class and rank, if known, are passed to the associate name. If
            a function result exists, pass its typespec to the associate
            name.
            * primary.cc (resolvable_fcns): New function to check that all
            the function references are resolvable.
            (gfc_match_varspec): If a scalar derived type select type
            temporary has an array reference, match the array reference,
            treating this in the same way as an equivalence member. Do not
            set 'inquiry' if applied to an unknown type the inquiry name
            is ambiguous with the component of an accessible derived type.
            Check that resolution of the target expression is OK by testing
            if the symbol is declared or is an operator expression, then
            using 'resolvable_fcns' recursively. If all is well, resolve
            the expression. If this is an inferred type with a component
            reference, call 'gfc_find_derived_types' to find a suitable
            derived type. If there is an inquiry ref and the symbol either
            is of unknown type or is inferred to be a derived type, set the
            primary and symbol TKR appropriately.
            * resolve.cc (resolve_variable): Call new function below.
            (gfc_fixup_inferred_type_refs): New function to ensure that the
            expression references for a inferred type are consistent with
            the now fixed up selector.
            (resolve_assoc_var): Ensure that derived type or class function
            selectors transmit the correct arrayspec to the associate name.
            (resolve_select_type): If the selector is an associate name of
            inferred type and has no component references, the associate
            name should have its typespec. Simplify the conversion of a
            class array to class scalar by calling 'gfc_change_class'.
            Make sure that a class, inferred type selector with an array
            ref transfers the typespec from the symbol to the expression.
            * symbol.cc (gfc_set_default_type): If an associate name with
            unknown type has a selector expression, try resolving the expr.
            (find_derived_types, gfc_find_derived_types): New functions
            that search for a derived type with a given name.
            * trans-expr.cc (gfc_conv_variable): Some inferred type exprs
            escape resolution so call 'gfc_fixup_inferred_type_refs'.
            * trans-stmt.cc (trans_associate_var): Tidy up expression for
            'class_target'. Finalize and free class function results.
            Correctly handle selectors that are class functions and class
            array references, passed as derived types.

    gcc/testsuite/
            PR fortran/87477
            PR fortran/89645
            PR fortran/99065
            * gfortran.dg/associate_64.f90 : New test
            * gfortran.dg/associate_66.f90 : New test
            * gfortran.dg/associate_67.f90 : New test

            PR fortran/114141
            * gfortran.dg/associate_65.f90 : New test

            PR fortran/114280
            * gfortran.dg/associate_68.f90 : New test

[Bug fortran/99065] ASSOCIATE function selector expression "no IMPLICIT type" failure

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99065

--- Comment #4 from Paul Thomas <pault at gcc dot gnu.org> ---
This mega-patch, on the scale of the importance of the problem, was required
because of gfortran's one pass parsing. It might be a temporary fix because I
am contemplating how an initial pass of contained procedures might be
introduced.

Fixed on mainline.

Paul