1  /* PR middle-end/96963 - -Wstringop-overflow false positive with
       2     -ftree-vectorize when assigning consecutive char struct members
       3     { dg-do compile }
       4     { dg-options "-O2 -Wall -ftree-vectorize" } */
       5  
       6  void sink (void*);
       7  
       8  struct Char
       9  {
      10    int i;
      11    char c, d, e, f;
      12    char a[2], b[2];
      13  };
      14  
      15  void nowarn_char_assign (struct Char *p)
      16  {
      17    sink (&p->c);
      18  
      19    /* Verify the bogus warning triggered by the tree-ssa-strlen.c pass
      20       is not issued.  */
      21    p->c = 1;         // { dg-bogus "\\\[-Wstringop-overflow" }
      22    p->d = 2;
      23    p->e = 3;
      24    p->f = 4;
      25  }
      26  
      27  void nowarn_char_array_assign (struct Char *p)
      28  {
      29    sink (p->a);
      30  
      31    p->a[0] = 1;      // { dg-bogus "\\\[-Wstringop-overflow" }
      32    p->a[1] = 2;
      33    p->b[0] = 3;
      34    p->b[1] = 4;
      35  }
      36  
      37  void warn_char_array_assign_interior (struct Char *p)
      38  {
      39    sink (p->a);
      40  
      41    p->a[0] = 1;
      42    p->a[1] = 2;
      43  #pragma GCC diagnostic push
      44  #pragma GCC diagnostic ignored "-Warray-bounds"
      45    /* Warnings are only suppressed for trailing arrays.  Verify
      46       one is issued for an interior array.  */
      47    p->a[2] = 5;      // { dg-warning "\\\[-Wstringop-overflow" }
      48  #pragma GCC diagnostic pop
      49  }
      50  
      51  void warn_char_array_assign_trailing (struct Char *p)
      52  {
      53    /* This is separated from warn_char_array_assign_interior because
      54       otherwise GCC removes the store to p->a[2] as dead since it's
      55       overwritten by p->b[0].  */
      56    sink (p->b);
      57  
      58    p->b[0] = 3;
      59    p->b[1] = 4;
      60  #pragma GCC diagnostic push
      61  #pragma GCC diagnostic ignored "-Warray-bounds"
      62    /* Warnings are only suppressed for trailing arrays with at most
      63       one element.  Verify one is issued for a two-element array.  */
      64    p->b[2] = 5;      // { dg-warning "\\\[-Wstringop-overflow" }
      65  #pragma GCC diagnostic pop
      66  }
      67  
      68  
      69  /* Also verify there's no warning for other types than char (even though
      70     the problem was limited to chars and -Wstringop-overflow should only
      71     trigger for character accesses).  */
      72  
      73  struct Short
      74  {
      75    int i;
      76    short c, d, e, f;
      77    short a[2], b[2];
      78  };
      79  
      80  void nowarn_short_assign (struct Short *p)
      81  {
      82    sink (&p->c);
      83  
      84    p->c = 1;
      85    p->d = 2;
      86    p->e = 3;
      87    p->f = 4;
      88  }
      89  
      90  void nowarn_short_array_assign (struct Short *p)
      91  {
      92    sink (p->a);
      93  
      94    p->a[0] = 1;
      95    p->a[1] = 2;
      96    p->b[0] = 3;
      97    p->b[1] = 4;
      98  }