gcc/testsuite/gcc.dg/Walways-true-2.c

   1 /* Make sure we don't assume that a weak symbol is always non-NULL.
   2    This is just like Walways-true-1.C, except that it uses a weak
   3    symbol.
   4    Origin: Ian Lance Taylor <iant@google.com>.  */
   5
   6 /* { dg-do compile } */
   7 /* { dg-options "-Waddress" } */
   8 /* { dg-require-weak "" } */
   9
  10 extern int foo (int) __attribute__ ((weak));
  11
  12 int i __attribute__ ((weak));
  13
  14 void
  15 bar (int a)
  16 {
  17  lab:
  18   if (foo)
  19     foo (0);
  20   if (foo (1))
  21     ;
  22   if (&i)
  23     foo (2);
  24   if (i)
  25     foo (3);
  26   if (&a)       /* { dg-warning "always evaluate as" "correct warning" } */
  27     foo (4);
  28   if (a)
  29     foo (5);
  30   if (&&lab)    /* { dg-warning "always evaluate as" "correct warning" } */
  31     foo (6);
  32   if (foo == 0)
  33     foo (7);
  34   if (foo (1) == 0)
  35     foo (8);
  36   if (&i == 0)
  37     foo (9);
  38   if (i == 0)
  39     foo (10);
  40   if (&a == 0)  /* { dg-warning "the comparison will always evaluate as 'false'" "correct warning" } */
  41     foo (11);
  42   if (a == 0)
  43     foo (12);
  44   if (&&lab == 0) /* { dg-warning "the comparison will always evaluate as 'false'" "correct warning" } */
  45     foo (13);
  46   if (0 == foo)
  47     foo (14);
  48   if (0 == foo (1))
  49     foo (15);
  50   if (0 == &i)
  51     foo (16);
  52   if (0 == i)
  53     foo (17);
  54   if (0 == &a)  /* { dg-warning "the comparison will always evaluate as 'false'" "correct warning" } */
  55     foo (18);
  56   if (0 == a)
  57     foo (19);
  58   if (0 == &&lab) /* { dg-warning "the comparison will always evaluate as 'false'" "correct warning" } */
  59     foo (20);
  60 }