[Bug fortran/125782] Double free failure with associate

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125782

--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jerry DeLisle <jvdelisle@gcc.gnu.org>:

https://gcc.gnu.org/g:e002a4e17481c1a083e2b49374565dbb2621aef8

commit r17-1552-ge002a4e17481c1a083e2b49374565dbb2621aef8
Author: Jerry DeLisle <jvdelisle@gcc.gnu.org>
Date:   Sat Jun 13 19:10:04 2026 -0700

    fortran: Fix double free in ASSOCIATE over allocatable char function
[PR125782]

    When an ASSOCIATE selector is a function call returning an allocatable
    deferred-length character, trans_associate_var unconditionally added an
    extra free of the associate-name's backend decl.  That free was added in
    2017 (PR60458/77296) to release the result of a POINTER-valued character
    function, which is not otherwise freed.  For an ALLOCATABLE-valued
    character function, however, the result temporary is already freed by the
    procedure call's own cleanup code, and the associate name aliases that
    same temporary, so the extra free caused a double free at the end of the
    ASSOCIATE block.

    Restrict the extra free to POINTER-valued function results, where it is
    still needed.

    Assisted by: Claude Sonnet 4.6

            PR fortran/125782

    gcc/fortran/ChangeLog:

            * trans-stmt.cc (trans_associate_var): Only free the associate
            name's backend decl for a deferred-length character function
            result when the result is a POINTER, not when it is
            ALLOCATABLE, since the latter is already freed by the
            procedure call's cleanup.

    gcc/testsuite/ChangeLog:

            * gfortran.dg/associate_82.f90: New test.