[Bug libstdc++/115824] New: Strange -Warray-bounds warning when assigning an initializer list to a vector of pointers

[mytbk920423 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115824

            Bug ID: 115824
           Summary: Strange -Warray-bounds warning when assigning an
                    initializer list to a vector of pointers
           Product: gcc
           Version: 12.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mytbk920423 at gmail dot com
  Target Milestone: ---

The following code has a strange warning on GCC 12.4.0 when compiled with -O2
-Warray-bounds. (compiler explorer link: https://godbolt.org/z/sr56Yro6n)

#include <vector>

std::vector<int *> v;

void test(int a) {
  int *p = new int(a);
  v = {p};
}


stl_algobase.h:434:30: warning: 'void* __builtin_memcpy(void*, const void*,
long unsigned int)' forming offset 8 is out of the bounds [0, 8] of object
'<anonymous>' with type 'int* const [1]' [-Warray-bounds]
  434 |             __builtin_memmove(__result, __first, sizeof(_Tp) * _Num);
      |             ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


In GCC release 12.3.0, 13.x, 14.x and trunk, there is no such warning. I think
it can be some problem in the libstdc++ change in 12.4.0 release.