public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug c++/98130] New: [11 regression] placement new fails on webkit-gtk-2.28.4
@ 2020-12-03 20:45 slyfox at gcc dot gnu.org
  2020-12-04  6:54 ` [Bug c++/98130] [11 regression] placement new fails on webkit-gtk-2.28.4 since r11-4745-g58c9de46541ade79 marxin at gcc dot gnu.org
                   ` (15 more replies)
  0 siblings, 16 replies; 17+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-12-03 20:45 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98130

            Bug ID: 98130
           Summary: [11 regression] placement new fails on
                    webkit-gtk-2.28.4
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: slyfox at gcc dot gnu.org
  Target Milestone: ---

Initial problem is observed on liferea crash at startup against
webkit-gtk-2.28.4 built with gcc-11.

If I reduced original source correctly here is minimized version of the crash:

//$ cat a.cc
/*

  $ g++-10.2.0 -O1 -fno-strict-aliasing a.cc -o a-10 && ./a-10
  &a=0x7ffc83475894
  $ g++-11.0.0 -O1 -fno-strict-aliasing a.cc -o a-11 && ./a-11
  Illegal instruction     (core dumped) ./a-11

*/

#if 0
#  include <memory>
#else
inline void* operator new(unsigned long, void* __p) { return __p; }
#endif

#include <stdio.h>

typedef int* T;

static T storage;
static T* p = &storage;

// '__attribute__((__always_inline__))' seems to be the trigger
static inline __attribute__((__always_inline__)) void append(T value)
{
    new (p) T(value);
}

int main() {
    int a;
    append(&a);

    if (!*p)
        __builtin_trap();
    fprintf(stderr, "&a=%p\n", *p);
}

^ permalink raw reply	[flat|nested] 17+ messages in thread
end of thread, other threads:[~2021-01-19 11:59 UTC | newest]

Thread overview: 17+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-03 20:45 [Bug c++/98130] New: [11 regression] placement new fails on webkit-gtk-2.28.4 slyfox at gcc dot gnu.org
2020-12-04  6:54 ` [Bug c++/98130] [11 regression] placement new fails on webkit-gtk-2.28.4 since r11-4745-g58c9de46541ade79 marxin at gcc dot gnu.org
2020-12-04  7:19 ` rguenth at gcc dot gnu.org
2020-12-04 11:27 ` jakub at gcc dot gnu.org
2020-12-04 11:37 ` jakub at gcc dot gnu.org
2020-12-04 11:59 ` hubicka at ucw dot cz
2020-12-04 12:21 ` rguenth at gcc dot gnu.org
2020-12-04 12:25 ` rguenth at gcc dot gnu.org
2020-12-04 12:33 ` jakub at gcc dot gnu.org
2020-12-04 12:37 ` marxin at gcc dot gnu.org
2020-12-04 12:48 ` jakub at gcc dot gnu.org
2020-12-04 13:33 ` rguenth at gcc dot gnu.org
2020-12-04 18:11 ` cvs-commit at gcc dot gnu.org
2020-12-04 18:12 ` jakub at gcc dot gnu.org
2020-12-04 19:49 ` slyfox at gcc dot gnu.org
2020-12-22 19:09 ` jason at gcc dot gnu.org
2021-01-19 11:59 ` rguenth at gcc dot gnu.org

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).