85 lines · cpp
1// RUN: %clang_cc1 -Wall -Wno-unused-but-set-variable -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify=expected,cxx17 -std=c++17 %s2// RUN: %clang_cc1 -Wall -Wno-unused-but-set-variable -Wshift-sign-overflow -ffreestanding -fsyntax-only -verify=expected,cxx2a -std=c++2a %s3 4#include <limits.h>5 6#define WORD_BIT (sizeof(int) * CHAR_BIT)7 8enum {9 X = 1 << 0,10 Y = 1 << 1,11 Z = 1 << 212};13 14void test() {15 char c;16 17 c = 0 << 0;18 c = 0 << 1;19 c = 1 << 0;20 c = 1 << -0;21 c = 1 >> -0;22 c = 1 << -1; // expected-warning {{shift count is negative}}23 c = 1 >> -1; // expected-warning {{shift count is negative}}24 c = 1 << (unsigned)-1; // expected-warning {{shift count >= width of type}}25 // expected-warning@-1 {{implicit conversion from 'int' to 'char' changes value from -2147483648 to 0}}26 c = 1 >> (unsigned)-1; // expected-warning {{shift count >= width of type}}27 c = 1 << c;28 c <<= 0;29 c >>= 0;30 c <<= 1;31 c >>= 1;32 c <<= -1; // expected-warning {{shift count is negative}}33 c >>= -1; // expected-warning {{shift count is negative}}34 c <<= 999999; // expected-warning {{shift count >= width of type}}35 c >>= 999999; // expected-warning {{shift count >= width of type}}36 c <<= CHAR_BIT; // expected-warning {{shift count >= width of type}}37 c >>= CHAR_BIT; // expected-warning {{shift count >= width of type}}38 c <<= CHAR_BIT+1; // expected-warning {{shift count >= width of type}}39 c >>= CHAR_BIT+1; // expected-warning {{shift count >= width of type}}40 (void)((long)c << CHAR_BIT);41 42 int i;43 i = 1 << (WORD_BIT - 2);44 i = 2 << (WORD_BIT - 1); // cxx17-warning {{bits to represent, but 'int' only has}}45 i = 1 << (WORD_BIT - 1); // cxx17-warning {{sets the sign bit of the shift expression}}46 i = -1 << (WORD_BIT - 1); // cxx17-warning {{shifting a negative signed value is undefined}}47 i = -1 << 0; // cxx17-warning {{shifting a negative signed value is undefined}}48 i = 0 << (WORD_BIT - 1);49 i = (char)1 << (WORD_BIT - 2);50 51 unsigned u;52 u = 1U << (WORD_BIT - 1);53 u = 5U << (WORD_BIT - 1);54 55 long long int lli;56 lli = INT_MIN << 2; // cxx17-warning {{shifting a negative signed value is undefined}}57 lli = 1LL << (sizeof(long long) * CHAR_BIT - 2);58}59 60#define a 061#define ashift 862enum { b = (a << ashift) };63 64// Don't warn for negative shifts in code that is unreachable.65void test_pr5544() {66 (void) (((1) > 63 && (1) < 128 ? (((unsigned long long) 1)<<((1)-64)) : (unsigned long long) 0)); // no-warning67}68 69void test_shift_too_much(char x) {70 if (0)71 (void) (x >> 80); // no-warning72 (void) (x >> 80); // expected-warning {{shift count >= width of type}}73}74 75typedef unsigned vec16 __attribute__((vector_size(16)));76typedef unsigned vec8 __attribute__((vector_size(8)));77 78void vect_shift_1(vec16 *x) { *x = *x << 4; }79 80void vect_shift_2(vec16 *x, vec16 y) { *x = *x << y; }81 82void vect_shift_3(vec16 *x, vec8 y) {83 *x = *x << y; // expected-error {{vector operands do not have the same number of elements}}84}85