gcc/testsuite/gcc.dg/strlenopt-41.c

   1 /* PR tree-optimization/83671 - fix for false positive reported by
   2    -Wstringop-overflow does not work with inlining
   3    Verify that the length the empty string is folded to zero even at -O1
   4    regardless of offset into it.
   5    Also verify that the length of a non-empty string isn't folded given
   6    a variable offset.
   7    { dg-do compile }
   8    { dg-options "-O1 -fdump-tree-optimized" } */
   9
  10 #include "strlenopt.h"
  11
  12 inline unsigned length (const char *s)
  13 {
  14   return __builtin_strlen (s);
  15 }
  16
  17 void check_length_cst (int i)
  18 {
  19   unsigned len = length (&""[i]);
  20
  21   if (len)
  22     __builtin_abort ();
  23 }
  24
  25 void check_length_var (int i)
  26 {
  27   unsigned len = length (&"1"[i]);
  28
  29   if (len != 1)
  30     __builtin_abort ();
  31 }
  32
  33 /* { dg-final { scan-tree-dump-times "abort" 1 "optimized" } }
  34    { dg-final { scan-tree-dump-times "strlen" 1 "optimized" } } */