1  /* PR tree-optimization/71625 - missing strlen optimization on different
       2     array initialization style
       3  
       4     Verify that zero-length array initialization results in the expected
       5     array sizes.
       6  
       7     { dg-do compile }
       8     { dg-options "-Wall -Wno-unused-local-typedefs" }  */
       9  
      10  #define A(expr) typedef char A[-1 + 2 * !!(expr)];
      11  
      12  const char a[] = { };
      13  
      14  A (sizeof a == 0);
      15  
      16  
      17  const char b[0] = { };
      18  
      19  A (sizeof b == 0);
      20  
      21  
      22  const char c[0] = { 1 };    /* { dg-warning "excess elements" } */
      23  
      24  A (sizeof c == 0);
      25  
      26  
      27  void test_auto_empty (void)
      28  {
      29    const char a[] = { };
      30  
      31    A (sizeof a == 0);
      32  }
      33  
      34  void test_auto_zero_length (void)
      35  {
      36    const char a[0] = { };
      37  
      38    A (sizeof a == 0);
      39  
      40    const char b[0] = { 0 };    /* { dg-warning "excess elements" } */
      41  
      42    A (sizeof b == 0);
      43  
      44    const char c[0] = "";
      45  
      46    A (sizeof c == 0);
      47  }
      48  
      49  
      50  void test_compound_zero_length (void)
      51  {
      52    A (sizeof (const char[]){ } == 0);
      53    A (sizeof (const char[0]){ } == 0);
      54    A (sizeof (const char[0]){ 0 } == 0);   /* { dg-warning "excess elements" } */
      55    A (sizeof (const char[0]){ 1 } == 0);   /* { dg-warning "excess elements" } */
      56    A (sizeof (const char[0]){ "" } == 0);
      57    A (sizeof (const char[0]){ "1" } == 0);  /* { dg-warning "too long" } */
      58  }