1  /* PR tree-optimization/85700 - Spurious -Wstringop-truncation warning
       2     with strncat
       3     { dg-do compile }
       4     { dg-options "-O2 -Wno-stringop-overflow -Wstringop-truncation -ftrack-macro-expansion=0" } */
       5  
       6  #define NOIPA __attribute__ ((noipa))
       7  #define strncat __builtin_strncat
       8  #define strlen __builtin_strlen
       9  
      10  extern char a4[4], b4[4], ax[];
      11  
      12  NOIPA void cat_a4_s1_1 (void)
      13  {
      14    /* There is no truncation here but since the bound of 1 equals
      15       the length of the source string it's likely a mistake that
      16       could cause overflow so it's diagnosed by -Wstringop-overflow */
      17    strncat (a4, "1", 1);
      18  }
      19  
      20  NOIPA void cat_a4_s1_2 (void)
      21  {
      22    strncat (a4, "1", 2);
      23  }
      24  
      25  NOIPA void cat_a4_s1_3 (void)
      26  {
      27    strncat (a4, "1", 3);
      28  }
      29  
      30  NOIPA void cat_a4_s1_4 (void)
      31  {
      32    /* There is no truncation here but since the bound of 1 equals
      33       the length of the source string it's likely a mistake that
      34       could cause overflow so it's diagnosed by -Wstringop-overflow */
      35    strncat (a4, "1", 4);
      36  }
      37  
      38  NOIPA void cat_a4_s1_5 (void)
      39  {
      40    /* A bound in excess of the destination size is diagnosed by
      41       -Wstringop-overflow.  */
      42    strncat (a4, "1", 5);
      43  }
      44  
      45  NOIPA void cat_a4_s1_dlen (void)
      46  {
      47    strncat (a4, "1", sizeof a4 - strlen (a4) - 1);
      48  }
      49  
      50  NOIPA void cat_a4_s2_dlen (void)
      51  {
      52    strncat (a4, "12", sizeof a4 - strlen (a4) - 1);  /* { dg-bogus "\\\[-Wstringop-truncation]" } */
      53  }
      54  
      55  NOIPA void cat_a4_b4_dlen (void)
      56  {
      57    strncat (a4, b4, sizeof a4 - strlen (a4) - 1);  /* { dg-bogus "\\\[-Wstringop-truncation]" } */
      58  }
      59  
      60  NOIPA void cat_ax_b4_dlen (void)
      61  {
      62    strncat (ax, b4, 32 - strlen (ax) - 1);  /* { dg-bogus "\\\[-Wstringop-truncation]" } */
      63  }