[Bug middle-end/90348] [9/10/11/12 Regression] Partition of char arrays is incorrect in some cases

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90348

--- Comment #24 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:551aa75778a4c5165d9533cd447c8fc822f583e1

commit r12-7044-g551aa75778a4c5165d9533cd447c8fc822f583e1
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Feb 2 14:24:39 2022 +0100

    Add CLOBBER_EOL to mark storage end-of-life clobbers

    This adds a flag to CONSTRUCTOR nodes indicating that for
    clobbers this marks the end-of-life of storage as opposed to
    just ending the lifetime of the object that occupied it.
    The dangling pointer diagnostics uses CLOBBERs but is confused
    by those emitted by the C++ frontend for example which emits
    them for the second purpose at the start of CTORs.  The issue
    is also appearant for aarch64 in PR104092.

    Distinguishing the two cases is also necessary for the PR90348 fix.

    Since I'm going to add another flag I added an enum clobber_flags
    and a defaulted argument to build_clobber plus a convenient way to
    query the enum from the CTOR tree and specify it for gimple_clobber_p.
    Since 'CLOBBER' is already taken and I needed a name for the unspecified
    clobber we have now I used 'CLOBBER_UNDEF'.

    2022-02-03  Richard Biener  <rguenther@suse.de>

            PR middle-end/90348
            PR middle-end/104092
    gcc/
            * tree-core.h (clobber_kind): New enum.
            (tree_base::u::bits::address_space): Document use in CONSTRUCTORs.
            * tree.h (CLOBBER_KIND): Add.
            (build_clobber): Add clobber kind argument, defaulted to
            CLOBBER_UNDEF.
            * tree.cc (build_clobber): Likewise.
            * gimple.h (gimple_clobber_p): New overload with specified kind.
            * tree-streamer-in.cc (streamer_read_tree_bitfields): Stream
            CLOBBER_KIND.
            * tree-streamer-out.cc (streamer_write_tree_bitfields):
            Likewise.
            * tree-pretty-print.cc (dump_generic_node): Mark EOL CLOBBERs.
            * gimplify.cc (gimplify_bind_expr): Build storage end-of-life
clobbers
            with CLOBBER_EOL.
            (gimplify_target_expr): Likewise.
            * tree-inline.cc (expand_call_inline): Likewise.
            * tree-ssa-ccp.cc (insert_clobber_before_stack_restore): Likewise.
            * gimple-ssa-warn-access.cc (pass_waccess::check_stmt): Only treat
            CLOBBER_EOL clobbers as ending lifetime of storage.

    gcc/lto/
            * lto-common.cc (compare_tree_sccs_1): Compare CLOBBER_KIND.

    gcc/testsuite/
            * gcc.dg/pr87052.c: Adjust.