[Bug middle-end/63272] GCC should warn when using pointer to dead scoped variable within the same function

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63272

--- Comment #8 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:9d6a0f388eb048f8d87f47af78f07b5ce513bfe6

commit r12-6606-g9d6a0f388eb048f8d87f47af78f07b5ce513bfe6
Author: Martin Sebor <mse...@redhat.com>
Date:   Sat Jan 15 16:41:40 2022 -0700

    Add -Wdangling-pointer [PR63272].

    Resolves:
    PR c/63272 - GCC should warn when using pointer to dead scoped variable
with
    in the same function

    gcc/c-family/ChangeLog:

            PR c/63272
            * c.opt (-Wdangling-pointer): New option.

    gcc/ChangeLog:

            PR c/63272
            * diagnostic-spec.c (nowarn_spec_t::nowarn_spec_t): Handle
            -Wdangling-pointer.
            * doc/invoke.texi (-Wdangling-pointer): Document new option.
            * gimple-ssa-warn-access.cc (pass_waccess::clone): Set new member.
            (pass_waccess::check_pointer_uses): New function.
            (pass_waccess::gimple_call_return_arg): New function.
            (pass_waccess::gimple_call_return_arg_ref): New function.
            (pass_waccess::check_call_dangling): New function.
            (pass_waccess::check_dangling_uses): New function overloads.
            (pass_waccess::check_dangling_stores): New function.
            (pass_waccess::check_dangling_stores): New function.
            (pass_waccess::m_clobbers): New data member.
            (pass_waccess::m_func): New data member.
            (pass_waccess::m_run_number): New data member.
            (pass_waccess::m_check_dangling_p): New data member.
            (pass_waccess::check_alloca): Check m_early_checks_p.
            (pass_waccess::check_alloc_size_call): Same.
            (pass_waccess::check_strcat): Same.
            (pass_waccess::check_strncat): Same.
            (pass_waccess::check_stxcpy): Same.
            (pass_waccess::check_stxncpy): Same.
            (pass_waccess::check_strncmp): Same.
            (pass_waccess::check_memop_access): Same.
            (pass_waccess::check_read_access): Same.
            (pass_waccess::check_builtin): Call check_pointer_uses.
            (pass_waccess::warn_invalid_pointer): Add arguments.
            (is_auto_decl): New function.
            (pass_waccess::check_stmt): New function.
            (pass_waccess::check_block): Call check_stmt.
            (pass_waccess::execute): Call check_dangling_uses,
            check_dangling_stores.  Empty m_clobbers.
            * passes.def (pass_warn_access): Invoke pass two more times.

    gcc/testsuite/ChangeLog:

            PR c/63272
            * g++.dg/warn/Wfree-nonheap-object-6.C: Disable valid warnings.
            * g++.dg/warn/ref-temp1.C: Prune expected warning.
            * gcc.dg/uninit-pr50476.c: Expect a new warning.
            * c-c++-common/Wdangling-pointer-2.c: New test.
            * c-c++-common/Wdangling-pointer-3.c: New test.
            * c-c++-common/Wdangling-pointer-4.c: New test.
            * c-c++-common/Wdangling-pointer-5.c: New test.
            * c-c++-common/Wdangling-pointer-6.c: New test.
            * c-c++-common/Wdangling-pointer.c: New test.
            * g++.dg/warn/Wdangling-pointer-2.C: New test.
            * g++.dg/warn/Wdangling-pointer.C: New test.
            * gcc.dg/Wdangling-pointer-2.c: New test.
            * gcc.dg/Wdangling-pointer.c: New test.