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 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); // expected-warning {{shifting a negative signed value is undefined}} 43 i = -1 << 0; // expected-warning {{shifting a negative signed value is undefined}} 44 i = 0 << (WORD_BIT - 1); 45 i = (char)1 << (WORD_BIT - 2); 46 47 unsigned u; 48 u = 1U << (WORD_BIT - 1); 49 u = 5U << (WORD_BIT - 1); 50 51 long long int lli; 52 lli = INT_MIN << 2; // expected-warning {{shifting a negative signed value is undefined}} 53 lli = 1LL << (sizeof(long long) * CHAR_BIT - 2); 54 } 55 56 #define a 0 57 #define ashift 8 58 enum { b = (a << ashift) }; 59 60 // Don't warn for negative shifts in code that is unreachable. 61 void test_pr5544() { 62 (void) (((1) > 63 && (1) < 128 ? (((unsigned long long) 1)<<((1)-64)) : (unsigned long long) 0)); // no-warning 63 } 64 65 void test_shift_too_much(char x) { 66 if (0) 67 (void) (x >> 80); // no-warning 68 (void) (x >> 80); // expected-warning {{shift count >= width of type}} 69 } 70
