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" } } */