[Bug fortran/125535] Wrong-code for implied-do with allocatable-component derived type and transformational intrinsic

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125535

--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-16 branch has been updated by Jerry DeLisle
<jvdelisle@gcc.gnu.org>:

https://gcc.gnu.org/g:1da2423372115bf33c9885ccd681ca800d848e49

commit r16-9111-g1da2423372115bf33c9885ccd681ca800d848e49
Author: Jerry DeLisle <jvdelisle@gcc.gnu.org>
Date:   Thu Jun 11 18:50:37 2026 -0700

    fortran: [PR125535] Plug remaining leak in implied-do array constructor
with allocatable components

    Follow-up to the PR fortran/125535 wrong-code fix (commit 1b8421e9d5b,
    already pushed): that fix corrected the *values* produced by an
    implied-do array constructor of derived-type function results with
    allocatable components, but left a separate memory leak in the same
    code path.

    An array constructor whose implied-do produces function results of a
    derived type with allocatable components moves each result into the
    constructor temporary, so the temporary owns those components.  The
    per-element finalization in gfc_trans_array_ctor_element only freed
    the single slot referenced by the final loop offset, leaking the
    allocatable components of every other element the loop produced.

    A whole-array sweep is the only way to free every slot written by an
    implied-do, but it may be used only when every element is an owned
    function result: a variable element is shallow-copied into the
    temporary and its components are aliased rather than owned, so freeing
    them would double free.  Add gfc_constructor_is_owned_alloc_comp to
    detect the all-owned case and, when it holds, suppress the per-element
    finalization and emit a single gfc_deallocate_alloc_comp_no_caf over
    the whole temporary.

    Assisted-by: Claude Opus 4.8

            PR fortran/125535

    gcc/fortran/ChangeLog:

            * trans-array.cc (gfc_constructor_is_owned_alloc_comp): New
function.
            (gfc_trans_array_constructor_value): Add OWNED_SWEEP parameter and,
            when set, suppress the per-element finalization.  Pass it through
the
            recursive call.
            (trans_array_constructor): Compute OWNED_SWEEP and, when set,
            deallocate the allocatable components of the whole temporary in one
            sweep.

    gcc/testsuite/ChangeLog:

            * gfortran.dg/asan/implied_do_alloc_comp_leak_1.f90: New test.

    (cherry picked from commit b2ec4ebcf914f32f51c35dbd9a2c98dab5841097)