gcc/testsuite/gcc.dg/Walways-true-1.c

   1 /* Test -Waddress for testing an address against NULL.
   2    Origin: Ian Lance Taylor <iant@google.com>.  */
   3
   4 /* { dg-do compile } */
   5 /* { dg-options "-Waddress -fshow-column" } */
   6
   7 extern int foo (int);
   8
   9 int i;
  10
  11 void
  12 bar (int a)
  13 {
  14  lab:
  15   if (foo)      /* { dg-warning "7:always evaluate as" "correct warning" } */
  16     foo (0);
  17   if (foo (1))
  18     ;
  19   if (&i)       /* { dg-warning "7:always evaluate as" "correct warning" } */
  20     foo (2);
  21   if (i)
  22     foo (3);
  23   if (&a)       /* { dg-warning "7:always evaluate as" "correct warning" } */
  24     foo (4);
  25   if (a)
  26     foo (5);
  27   if (&&lab)    /* { dg-warning "7:always evaluate as" "correct warning" } */
  28     foo (6);
  29   if (foo == 0) /* { dg-warning "11:the comparison will always evaluate as 'false'" "correct warning" } */
  30     foo (7);
  31   if (foo (1) == 0)
  32     foo (8);
  33   if (&i == 0)  /* { dg-warning "10:the comparison will always evaluate as 'false'" "correct warning" } */
  34     foo (9);
  35   if (i == 0)
  36     foo (10);
  37   if (&a == 0)  /* { dg-warning "10:the comparison will always evaluate as 'false'" "correct warning" } */
  38     foo (11);
  39   if (a == 0)
  40     foo (12);
  41   if (&&lab == 0) /* { dg-warning "13:the comparison will always evaluate as 'false'" "correct warning" } */
  42     foo (13);
  43   if (0 == foo) /* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
  44     foo (14);
  45   if (0 == foo (1))
  46     foo (15);
  47   if (0 == &i)  /* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
  48     foo (16);
  49   if (0 == i)
  50     foo (17);
  51   if (0 == &a)  /* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
  52     foo (18);
  53   if (0 == a)
  54     foo (19);
  55   if (0 == &&lab) /* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
  56     foo (20);
  57 }