gcc/testsuite/gcc.dg/init-string-3.c

   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 }