gcc/testsuite/c-c++-common/Wshift-negative-value-2.c

   1 /* PR c/65179 */
   2 /* { dg-do compile } */
   3 /* { dg-options "-O -Wshift-negative-value" } */
   4 /* { dg-additional-options "-std=c++11" { target c++ } } */
   5
   6 enum E {
   7   A = 0 << 1,
   8   B = 1 << 1,
   9   C = -1 << 1, /* { dg-warning "10:left shift of negative value" } */
  10   /* { dg-error "not an integer constant" "no constant" { target c++ } .-1 } */
  11   /* { dg-error "left operand of shift expression" "shift" { target c++ } .-2 } */
  12   D = 0 >> 1,
  13   E = 1 >> 1,
  14   F = -1 >> 1
  15 };
  16
  17 int
  18 left (int x)
  19 {
  20   /* Warn for LSHIFT_EXPR.  */
  21   const int z = 0;
  22   const int o = 1;
  23   const int m = -1;
  24   int r = 0;
  25   r += z << x;
  26   r += o << x;
  27   r += m << x; /* { dg-warning "10:left shift of negative value" } */
  28   r += 0 << x;
  29   r += 1 << x;
  30   r += -1 << x; /* { dg-warning "11:left shift of negative value" } */
  31   r += -1U << x;
  32   return r;
  33 }
  34
  35 int
  36 right (int x)
  37 {
  38   /* Shouldn't warn for RSHIFT_EXPR.  */
  39   const int z = 0;
  40   const int o = 1;
  41   const int m = -1;
  42   int r = 0;
  43   r += z >> x;
  44   r += o >> x;
  45   r += m >> x;
  46   r += 0 >> x;
  47   r += 1 >> x;
  48   r += -1 >> x;
  49   r += -1U >> x;
  50   return r;
  51 }