xref: /openbsd-src/gnu/usr.bin/gcc/gcc/testsuite/gcc.dg/compare4.c (revision f6aab3d83b51b91c24247ad2c2573574de475a82)
1 /* Test for a bogus warning on comparison between signed and unsigned.
2    Origin: Kaveh R. Ghazi <ghazi@caip.rutgers.edu> 5/13/2001.  */
3 
4 /* { dg-do compile } */
5 /* { dg-options "-Wsign-compare" } */
6 
7 extern void bar(void);
8 
9 int foo(int x, int y, unsigned u)
10 {
11   /* A COMPOUND_EXPR is non-negative if the last element is known to
12      be non-negative.  */
13   if (u < (bar(), -1)) /*{ dg-warning "signed and unsigned" "COMPOUND_EXPR" }*/
14     return x;
15   if (u < (bar(), 10))
16     return x;
17   if ((bar(), 10) < u)
18     return x;
19   if (u < (x ? (bar(),bar(),bar(),bar(),x==y) : 10))
20     return x;
21   if ((x ? 10 : (bar(),bar(),bar(),bar(),x==y)) < u)
22     return x;
23 
24   /* Test an ABS_EXPR, which is by definition non-negative.  */
25   if (u < __builtin_abs(x))
26     return x;
27   if (__builtin_abs(x) < u)
28     return x;
29   if (u < (x ? __builtin_abs(x) : 10))
30     return x;
31   if ((x ? 10: __builtin_abs(x)) < u)
32     return x;
33 
34   /* A MODIFY_EXPR is non-negative if the new value is known to be
35      non-negative.  */
36   if (u < (x = -1)) /* { dg-warning "signed and unsigned" "MODIFY_EXPR" } */
37     return x;
38   if (u < (x = 10))
39     return x;
40   if ((x = 10) < u)
41     return x;
42   if (u < (x = (y ? (x==y) : 10)))
43     return x;
44   if ((x = (y ? 10 : (x==y))) < u)
45     return x;
46 
47   return 0;
48 }
49