[Bug tree-optimization/80532] warning on pointer access after free

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80532

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Martin Sebor <mse...@gcc.gnu.org>:

https://gcc.gnu.org/g:671a283636de75f7ed638ee6b01ed2d44361b8b6

commit r12-6605-g671a283636de75f7ed638ee6b01ed2d44361b8b6
Author: Martin Sebor <mse...@redhat.com>
Date:   Sat Jan 15 16:37:54 2022 -0700

    Add -Wuse-after-free [PR80532].

    gcc/c-family/ChangeLog

            PR tree-optimization/80532
            * c.opt (-Wuse-after-free): New options.

    gcc/ChangeLog:

            PR tree-optimization/80532
            * common.opt (-Wuse-after-free): New options.
            * diagnostic-spec.c (nowarn_spec_t::nowarn_spec_t): Handle
            OPT_Wreturn_local_addr and OPT_Wuse_after_free_.
            * diagnostic-spec.h (NW_DANGLING): New enumerator.
            * doc/invoke.texi (-Wuse-after-free): Document new option.
            * gimple-ssa-warn-access.cc (pass_waccess::check_call): Rename...
            (pass_waccess::check_call_access): ...to this.
            (pass_waccess::check): Rename...
            (pass_waccess::check_block): ...to this.
            (pass_waccess::check_pointer_uses): New function.
            (pass_waccess::gimple_call_return_arg): New function.
            (pass_waccess::warn_invalid_pointer): New function.
            (pass_waccess::check_builtin): Handle free and realloc.
            (gimple_use_after_inval_p): New function.
            (get_realloc_lhs): New function.
            (maybe_warn_mismatched_realloc): New function.
            (pointers_related_p): New function.
            (pass_waccess::check_call): Call check_pointer_uses.
            (pass_waccess::execute): Compute and free dominance info.

    libcpp/ChangeLog:

            * files.c (_cpp_find_file): Substitute a valid pointer for
            an invalid one to avoid -Wuse-after-free.

    libiberty/ChangeLog:

            * regex.c: Suppress -Wuse-after-free.

    gcc/testsuite/ChangeLog:

            PR tree-optimization/80532
            * gcc.dg/Wmismatched-dealloc-2.c: Avoid -Wuse-after-free.
            * gcc.dg/Wmismatched-dealloc-3.c: Same.
            * gcc.dg/analyzer/file-1.c: Prune expected warning.
            * gcc.dg/analyzer/file-2.c: Same.
            * gcc.dg/attr-alloc_size-6.c: Disable -Wuse-after-free.
            * gcc.dg/attr-alloc_size-7.c: Same.
            * c-c++-common/Wuse-after-free-2.c: New test.
            * c-c++-common/Wuse-after-free-3.c: New test.
            * c-c++-common/Wuse-after-free-4.c: New test.
            * c-c++-common/Wuse-after-free-5.c: New test.
            * c-c++-common/Wuse-after-free-6.c: New test.
            * c-c++-common/Wuse-after-free-7.c: New test.
            * c-c++-common/Wuse-after-free.c: New test.
            * g++.dg/warn/Wmismatched-dealloc-3.C: New test.
            * g++.dg/warn/Wuse-after-free.C: New test.