[Bug c++/95221] New: g++.dg/ubsan/vptr-12.C fails with -fstrong-eval-order=all

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95221

            Bug ID: 95221
           Summary: g++.dg/ubsan/vptr-12.C fails with
                    -fstrong-eval-order=all
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mpolacek at gcc dot gnu.org
  Target Milestone: ---

It's this code:

struct MyClass
{
  virtual ~MyClass () {}
  virtual void Doit () {}
};

int
main ()
{
  MyClass *c = new MyClass;
  c->~MyClass ();
  c->Doit ();

  return 0;
}

$ g++ vptr-12.C -fsanitize=vptr -fno-sanitize-recover=vptr
-fstrong-eval-order=some; ./a.out
vptr-12.C:16:11: runtime error: member call on address 0x000000a25eb0 which
does not point to an object of type 'MyClass'
0x000000a25eb0: note: object has invalid vptr
 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00
00 00 00  41 f1 00 00
              ^~~~~~~~~~~~~~~~~~~~~~~
              invalid vptr

but

$ g++ vptr-12.C -fsanitize=vptr -fno-sanitize-recover=vptr
-fstrong-eval-order=all; ./a.out
Segmentation fault (core dumped)

This is important because C++17 implies -fstrong-eval-order=all.