1  /* PR tree-optimization/87028 - false positive -Wstringop-truncation
       2     strncpy with global variable source string
       3     { dg-do compile }
       4     { dg-options "-O2 -Wstringop-truncation" } */
       5  
       6  char *strncpy (char *, const char *, __SIZE_TYPE__);
       7  
       8  #define STR   "1234567890"
       9  
      10  struct S
      11  {
      12    char a[5], b[5];
      13  };
      14  
      15  const char arr[] = STR;
      16  const char* const ptr = STR;
      17  
      18  const char arr2[][10] = { "123", STR };
      19  
      20  void test_literal (struct S *s)
      21  {
      22    strncpy (s->a, STR, sizeof s->a - 1);     /* { dg-bogus "\\\[-Wstringop-truncation]" } */
      23    s->a[sizeof s->a - 1] = '\0';
      24  }
      25  
      26  void test_global_arr (struct S *s)
      27  {
      28    strncpy (s->a, arr, sizeof s->a - 1);     /* { dg-bogus "\\\[-Wstringop-truncation]" } */
      29    s->a [sizeof s->a - 1] = '\0';
      30  }
      31  
      32  void test_global_arr2 (struct S *s)
      33  {
      34    strncpy (s->a, arr2[1], sizeof s->a - 1); /* { dg-bogus "\\\[-Wstringop-truncation]" } */
      35    s->a [sizeof s->a - 1] = '\0';
      36  
      37    strncpy (s->b, arr2[0], sizeof s->a - 1);
      38  }
      39  
      40  void test_global_ptr (struct S *s)
      41  {
      42    strncpy (s->a, ptr, sizeof s->a - 1);     /* { dg-bogus "\\\[-Wstringop-truncation]" } */
      43    s->a [sizeof s->a - 1] = '\0';
      44  }
      45  
      46  void test_local_arr (struct S *s)
      47  {
      48    const char arr[] = STR;
      49    strncpy (s->a, arr, sizeof s->a - 1);
      50    s->a [sizeof s->a - 1] = '\0';
      51  }
      52  
      53  void test_local_ptr (struct S *s)
      54  {
      55    const char* const ptr = STR;
      56    strncpy (s->a, ptr, sizeof s->a - 1);     /* { dg-bogus "\\\[-Wstringop-truncation]" } */
      57    s->a [sizeof s->a - 1] = '\0';
      58  }
      59  
      60  void test_compound_literal (struct S *s)
      61  {
      62    strncpy (s->a, (char[]){ STR }, sizeof s->a - 1);
      63    s->a [sizeof s->a - 1] = '\0';
      64  }