gcc/testsuite/gcc.dg/c99-const-expr-3.c

   1 /* Test for constant expressions: broken optimization with const variables.  */
   2 /* Origin: Joseph Myers <jsm28@cam.ac.uk> */
   3 /* { dg-do compile } */
   4 /* { dg-options "-std=iso9899:1999 -O2" } */
   5 /* Note: not using -pedantic since the -std option alone should be enough
   6    to give the correct behavior to conforming programs.  */
   7
   8 static const int ZERO = 0;
   9 static const double DZERO = 0;
  10
  11 int *a;
  12 int b;
  13 long *c;
  14
  15 /* Assertion that n is a constant zero: so the conditional expression
  16    has type 'int *' instead of 'void *'.
  17 */
  18 #define ASSERT_NPC(n)   (b = *(1 ? a : (n)))
  19 /* Assertion that n is not a constant zero: so the conditional
  20    expressions has type 'void *' instead of 'int *'.
  21 */
  22 #define ASSERT_NOT_NPC(n)       (c = (1 ? a : (void *)(__SIZE_TYPE__)(n)))
  23
  24 void
  25 foo (void)
  26 {
  27   ASSERT_NPC (0);
  28   ASSERT_NOT_NPC (ZERO);
  29   ASSERT_NPC (0 + 0);
  30   ASSERT_NOT_NPC (ZERO + 0); /* { dg-bogus "incompatible" "bogus null pointer constant" } */
  31   ASSERT_NOT_NPC (ZERO + ZERO); /* { dg-bogus "incompatible" "bogus null pointer constant" } */
  32   ASSERT_NPC (+0);
  33   ASSERT_NOT_NPC (+ZERO); /* { dg-bogus "incompatible" "bogus null pointer constant" } */
  34   ASSERT_NPC (-0);
  35   ASSERT_NOT_NPC (-ZERO); /* { dg-bogus "incompatible" "bogus null pointer constant" } */
  36   ASSERT_NPC ((char) 0);
  37   ASSERT_NOT_NPC ((char) ZERO);
  38   ASSERT_NPC ((int) 0);
  39   ASSERT_NOT_NPC ((int) ZERO);
  40   ASSERT_NPC ((int) 0.0);
  41   ASSERT_NOT_NPC ((int) DZERO);
  42   ASSERT_NOT_NPC ((int) +0.0); /* { dg-bogus "incompatible" "bogus null pointer constant" } */
  43   ASSERT_NOT_NPC ((int) (0.0+0.0)); /* { dg-bogus "incompatible" "bogus null pointer constant" } */
  44   ASSERT_NOT_NPC ((int) (double)0.0); /* { dg-bogus "incompatible" "bogus null pointer constant" } */
  45 }