[Bug middle-end/94527] RFE: Add an __attribute__ that marks a function as freeing an object

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94527

--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Martin Sebor <msebor@gcc.gnu.org>:

https://gcc.gnu.org/g:dce6c58db87ebf7f4477bd3126228e73e4eeee97

commit r11-5732-gdce6c58db87ebf7f4477bd3126228e73e4eeee97
Author: Martin Sebor <msebor@redhat.com>
Date:   Thu Dec 3 15:41:25 2020 -0700

    Add support for detecting mismatched allocation/deallocation calls.

    PR c++/90629 - Support for -Wmismatched-new-delete
    PR middle-end/94527 - Add an __attribute__ that marks a function as freeing
an object

    gcc/ChangeLog:

            PR c++/90629
            PR middle-end/94527
            * builtins.c (access_ref::access_ref): Initialize new member.
            (compute_objsize): Use access_ref::deref.  Handle simple pointer
            assignment.
            (expand_builtin): Remove handling of the free built-in.
            (call_dealloc_argno): Same.
            (find_assignment_location): New function.
            (fndecl_alloc_p): Same.
            (gimple_call_alloc_p): Same.
            (call_dealloc_p): Same.
            (matching_alloc_calls_p): Same.
            (warn_dealloc_offset): Same.
            (maybe_emit_free_warning): Same.
            * builtins.h (struct access_ref): Declare new member.
            (maybe_emit_free_warning): Make extern.  Make use of access_ref.
            Handle -Wmismatched-new-delete.
            * calls.c (initialize_argument_information): Call
            maybe_emit_free_warning.
            * doc/extend.texi (attribute malloc): Update.
            * doc/invoke.texi (-Wfree-nonheap-object): Expand documentation.
            (-Wmismatched-new-delete): Document new option.
            (-Wmismatched-dealloc): Document new option.

    gcc/c-family/ChangeLog:

            PR c++/90629
            PR middle-end/94527
            * c-attribs.c (handle_dealloc_attribute): New function.
            (handle_malloc_attribute): Handle argument forms of attribute.
            * c.opt (-Wmismatched-dealloc): New option.
            (-Wmismatched-new-delete): New option.

    gcc/testsuite/ChangeLog:

            PR c++/90629
            PR middle-end/94527
            * g++.dg/asan/asan_test.cc: Fix a bug.
            * g++.dg/warn/delete-array-1.C: Add expected warning.
            * g++.old-deja/g++.other/delete2.C: Add expected warning.
            * g++.dg/warn/Wfree-nonheap-object-2.C: New test.
            * g++.dg/warn/Wfree-nonheap-object.C: New test.
            * g++.dg/warn/Wmismatched-new-delete.C: New test.
            * g++.dg/warn/Wmismatched-dealloc-2.C: New test.
            * g++.dg/warn/Wmismatched-dealloc.C: New test.
            * gcc.dg/Wmismatched-dealloc.c: New test.
            * gcc.dg/analyzer/malloc-1.c: Prune out expected warning.
            * gcc.dg/attr-malloc.c: New test.
            * gcc.dg/free-1.c: Adjust text of expected warning.
            * gcc.dg/free-2.c: Same.
            * gcc.dg/torture/pr71816.c: Prune out expected warning.
            * gcc.dg/tree-ssa/pr19831-2.c: Add an expected warning.
            * gcc.dg/Wfree-nonheap-object-2.c: New test.
            * gcc.dg/Wfree-nonheap-object-3.c: New test.
            * gcc.dg/Wfree-nonheap-object.c: New test.

    libstdc++-v3/ChangeLog:

            * testsuite/ext/vstring/modifiers/clear/56166.cc: Suppress a false
            positive warning.