[Bug tree-optimization/102586] [12 Regression] ICE in clear_padding_type, at gimple-fold.c:4798 since r12-3433-ga25e0b5e6ac8a77a

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102586

--- Comment #30 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:46c739d40c6c1028295931c53cf414d581519072

commit r12-8042-g46c739d40c6c1028295931c53cf414d581519072
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Apr 7 09:14:07 2022 +0200

    c++: Handle __builtin_clear_padding on non-trivially-copyable types
[PR102586]

    On Fri, Feb 11, 2022 at 07:55:50PM +0100, Jakub Jelinek via Gcc-patches
wrote:
    > Something like the
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102586#c16
    > will still be needed with adjusted testcase from
    > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102586#c15 such that
    > __builtin_clear_padding is called directly on var addresses rather than
    > in separate functions.

    Here is an updated version of the
    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102586#c15
    patch which uses FIELD_DECL in the langhook instead of its TREE_TYPE,
    and the testcases have been adjusted for the builtin accepting
    pointers to non-trivially-copyable types only if it is address of a
    declaration.

    2022-04-07  Jakub Jelinek  <jakub@redhat.com>

            PR tree-optimization/102586
    gcc/
            * langhooks.h (struct lang_hooks_for_types): Add classtype_as_base
            langhook.
            * langhooks-def.h (LANG_HOOKS_CLASSTYPE_AS_BASE): Define.
            (LANG_HOOKS_FOR_TYPES_INITIALIZER): Add it.
            * gimple-fold.cc (clear_padding_type): Use ftype instead of
            TREE_TYPE (field) some more.  For artificial FIELD_DECLs without
            name try the lang_hooks.types.classtype_as_base langhook and
            if it returns non-NULL, use that instead of ftype for recursive
call.
    gcc/cp/
            * cp-objcp-common.h (cp_classtype_as_base): Declare.
            (LANG_HOOKS_CLASSTYPE_AS_BASE): Redefine.
            * cp-objcp-common.cc (cp_classtype_as_base): New function.
    gcc/testsuite/
            * g++.dg/torture/builtin-clear-padding-5.C: New test.
            * g++.dg/cpp2a/builtin-clear-padding1.C (bar): Uncomment one
            call that is now accepted.