[Bug c++/114805] New: placement new doesn't check array length

[Bug c++/114805] New: placement new doesn't check array length

[pshevchuk at pshevchuk dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114805

            Bug ID: 114805
           Summary: placement new doesn't check array length
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pshevchuk at pshevchuk dot com
  Target Milestone: ---

Created attachment 58007
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58007&action=edit
Example code but as attachment

#include <new>
#include <cstdio>

int main()
{
    int sz = -1;
    char buf[9];
    char* res = new (buf) char[sz];
    std::puts(res == (char*) nullptr? "correct" : "wrong");
}

This program should output "correct", since:

expr.new.9: array bound is erroneous since it's less than zero before
conversion to std::size_t (9.1)

expr.new.9.5.1: the placement new is nothrow, so the result of this operation
must be nullptr. It isn't

Curiously, if you replace the allocated type with an array of ints, it will
incorrectly throw the std::bad_array_new_length exception instead of returning
nullptr

[Bug c++/114805] placement new doesn't check array length

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114805

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
dup

*** This bug has been marked as a duplicate of bug 114806 ***