File: warn-bitwise-compare.c

package info (click to toggle)
llvm-toolchain-3.9 1%3A3.9.1-9
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 441,144 kB
  • ctags: 428,836
  • sloc: cpp: 2,546,577; ansic: 538,318; asm: 119,677; objc: 103,316; python: 102,148; sh: 27,847; pascal: 5,626; ml: 5,510; perl: 5,293; lisp: 4,801; makefile: 2,177; xml: 686; cs: 362; php: 212; csh: 117
file content (28 lines) | stat: -rw-r--r-- 1,196 bytes parent folder | download | duplicates (16) 
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
 
// RUN: %clang_cc1 -fsyntax-only -verify -Wtautological-compare %s

#define mydefine 2

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 ((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) {}
}