gcc/testsuite/gcc.dg/strcmpopt_11.c

   1 /* Verify that strcmp doesn't make assumptions about the size of a weak
   2    symbol.
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall" } */
   5
   6 /* An ordinary definition of A with more elements might be provided
   7    in another translation unit.  Even though that would be undefined
   8    (the type of the actual definition must be the same as the type
   9    of the weak declaration) this test verifies that GCC doesn't rely
  10    on the size of this A for optimization (as a matter of QoI).  */
  11 __attribute__ ((weak)) char a[3];
  12
  13 int cmp_a3_x (void)
  14 {
  15   return __builtin_strcmp (a, "1234567") == 0;
  16 }