1 // RUN: %clang_cc1 -Wall -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify %s
2
3 #include <limits.h>
4
5 #define WORD_BIT (sizeof(int) * CHAR_BIT)
6
7 enum {
8 X = 1 << 0,
9 Y = 1 << 1,
10 Z = 1 << 2
11 };
12
test()13 void 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 {{sets 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
57 enum { b = (a << ashift) };
58
59 // Don't warn for negative shifts in code that is unreachable.
test_pr5544()60 void test_pr5544() {
61 (void) (((1) > 63 && (1) < 128 ? (((unsigned long long) 1)<<((1)-64)) : (unsigned long long) 0)); // no-warning
62 }
63
test_shift_too_much(char x)64 void test_shift_too_much(char x) {
65 if (0)
66 (void) (x >> 80); // no-warning
67 (void) (x >> 80); // expected-warning {{shift count >= width of type}}
68 }
69