gcc/testsuite/c-c++-common/Wshift-negative-value-1.c

   1 /* PR c/65179 */
   2 /* { dg-do compile } */
   3 /* { dg-options "-O -Wextra" } */
   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 "left shift of negative value|not an integer constant" } */
  10   /* { dg-error "left operand of shift expression" "shift" { target c++ } .-1 } */
  11   D = 0 >> 1,
  12   E = 1 >> 1,
  13   F = -1 >> 1
  14 };
  15
  16 int
  17 left (int x)
  18 {
  19   /* Warn for LSHIFT_EXPR.  */
  20   const int z = 0;
  21   const int o = 1;
  22   const int m = -1;
  23   int r = 0;
  24   r += z << x;
  25   r += o << x;
  26   r += m << x; /* { dg-warning "left shift of negative value" } */
  27   r += 0 << x;
  28   r += 1 << x;
  29   r += -1 << x; /* { dg-warning "left shift of negative value" } */
  30   r += -1U << x;
  31   return r;
  32 }
  33
  34 int
  35 right (int x)
  36 {
  37   /* Shouldn't warn for RSHIFT_EXPR.  */
  38   const int z = 0;
  39   const int o = 1;
  40   const int m = -1;
  41   int r = 0;
  42   r += z >> x;
  43   r += o >> x;
  44   r += m >> x;
  45   r += 0 >> x;
  46   r += 1 >> x;
  47   r += -1 >> x;
  48   r += -1U >> x;
  49   return r;
  50 }