shift.c revision 082bf7a47f78ff4a645cea358d70bf45a858b238 
1// RUN: %clang -Wall -Wshift-sign-overflow -ffreestanding -fsyntax-only -Xclang -verify %s
2
3#include <limits.h>
4
5#define WORD_BIT (sizeof(int) * CHAR_BIT)
6
7enum {
8  X = 1 << 0,
9  Y = 1 << 1,
10  Z = 1 << 2
11};
12
13void test() {
14  char c;
15
16  c = 0 << 0;
17  c = 0 << 1;
18  c = 1 << 0;
19  c = 1 << -0;
20  c = 1 >> -0;
21  c = 1 << -1; // expected-warning {{shift count is negative}}
22  c = 1 >> -1; // expected-warning {{shift count is negative}}
23  c = 1 << c;
24  c <<= 0;
25  c >>= 0;
26  c <<= 1;
27  c >>= 1;
28  c <<= -1; // expected-warning {{shift count is negative}}
29  c >>= -1; // expected-warning {{shift count is negative}}
30  c <<= 999999; // expected-warning {{shift count >= width of type}}
31  c >>= 999999; // expected-warning {{shift count >= width of type}}
32  c <<= CHAR_BIT; // expected-warning {{shift count >= width of type}}
33  c >>= CHAR_BIT; // expected-warning {{shift count >= width of type}}
34  c <<= CHAR_BIT+1; // expected-warning {{shift count >= width of type}}
35  c >>= CHAR_BIT+1; // expected-warning {{shift count >= width of type}}
36  (void)((long)c << CHAR_BIT);
37
38  int i;
39  i = 1 << (WORD_BIT - 2);
40  i = 2 << (WORD_BIT - 1); // expected-warning {{bits to represent, but 'int' only has}}
41  i = 1 << (WORD_BIT - 1); // expected-warning {{overrides the sign bit of the shift expression}}
42  i = -1 << (WORD_BIT - 1);
43  i = 0 << (WORD_BIT - 1);
44  i = (char)1 << (WORD_BIT - 2);
45
46  unsigned u;
47  u = 1U << (WORD_BIT - 1);
48  u = 5U << (WORD_BIT - 1);
49
50  long long int lli;
51  lli = INT_MIN << 2; // expected-warning {{bits to represent, but 'int' only has}}
52  lli = 1LL << (sizeof(long long) * CHAR_BIT - 2);
53}
54
55#define a 0
56#define ashift 8
57enum { b = (a << ashift) };
58
59// Don't warn for negative shifts in code that is unreachable.
60void test_pr5544() {
61  (void) (((1) > 63 && (1) < 128 ? (((unsigned long long) 1)<<((1)-64)) : (unsigned long long) 0)); // no-warning
62}
63