warn-bitwise-compare.c
1.98 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
// RUN: %clang_cc1 -fsyntax-only -verify -Wtautological-bitwise-compare %s
// RUN: %clang_cc1 -fsyntax-only -verify -Wall -Wno-unused %s
#define mydefine 2
enum {
ZERO,
ONE,
};
void f(int x) {
if ((8 & x) == 3) {} // expected-warning {{bitwise comparison always evaluates to false}}
if ((x & 8) == 4) {} // expected-warning {{bitwise comparison always evaluates to false}}
if ((x & 8) != 4) {} // expected-warning {{bitwise comparison always evaluates to true}}
if ((2 & x) != 4) {} // expected-warning {{bitwise comparison always evaluates to true}}
if ((x | 4) == 3) {} // expected-warning {{bitwise comparison always evaluates to false}}
if ((x | 3) != 4) {} // expected-warning {{bitwise comparison always evaluates to true}}
if ((5 | x) != 3) {} // expected-warning {{bitwise comparison always evaluates to true}}
if ((x & 0x15) == 0x13) {} // expected-warning {{bitwise comparison always evaluates to false}}
if ((0x23 | x) == 0x155){} // expected-warning {{bitwise comparison always evaluates to false}}
if (!!((8 & x) == 3)) {} // expected-warning {{bitwise comparison always evaluates to false}}
int y = ((8 & x) == 3) ? 1 : 2; // expected-warning {{bitwise comparison always evaluates to false}}
if ((x & 8) == 8) {}
if ((x & 8) != 8) {}
if ((x | 4) == 4) {}
if ((x | 4) != 4) {}
if ((x & 9) == 8) {}
if ((x & 9) != 8) {}
if ((x | 4) == 5) {}
if ((x | 4) != 5) {}
if ((x & mydefine) == 8) {}
if ((x | mydefine) == 4) {}
}
void g(int x) {
if (x | 5) {} // expected-warning {{bitwise or with non-zero value always evaluates to true}}
if (5 | x) {} // expected-warning {{bitwise or with non-zero value always evaluates to true}}
if (!((x | 5))) {} // expected-warning {{bitwise or with non-zero value always evaluates to true}}
if (x | -1) {} // expected-warning {{bitwise or with non-zero value always evaluates to true}}
if (x | ONE) {} // expected-warning {{bitwise or with non-zero value always evaluates to true}}
if (x | ZERO) {}
}