gcc/testsuite/gcc.dg/alias-16.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-Wstrict-aliasing=1 -fstrict-aliasing" } */
   3
   4 struct incomplete;
   5 struct s1 { int i; };
   6 struct s2 { double d; };
   7
   8 void
   9 f (int *i, double *d, struct s1 *s1, struct s2 *s2, char *c)
  10 {
  11   (char *) i;
  12   (char *) d;
  13   (char *) s1;
  14   (char *) s2;
  15   (char *) c;
  16
  17   (int *) i;
  18   (int *) d; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  19   (int *) s1; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  20   (int *) s2; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  21   (int *) c;
  22
  23   (double *) i; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  24   (double *) d;
  25   (double *) s1; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  26   (double *) s2; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  27   (double *) c;
  28
  29   (struct incomplete *) i; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  30   (struct incomplete *) d; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  31   (struct incomplete *) s1; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  32   (struct incomplete *) s2; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  33   (struct incomplete *) c; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  34
  35   (struct s1 *) i; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  36   (struct s1 *) d; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  37   (struct s1 *) s1;
  38   (struct s1 *) s2; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  39   (struct s1 *) c;
  40
  41   (struct s2 *) i; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  42   (struct s2 *) d; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  43   (struct s2 *) s1; /* { dg-warning "dereferencing type-punned pointer might break strict-aliasing rules" } */
  44   (struct s2 *) s2;
  45   (struct s2 *) c;
  46 }