| // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++20 -verify %s |
| // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++17 -verify=cxx17 %s |
| // RUN: %clang_cc1 -std=c++20 -verify=ref %s |
| // RUN: %clang_cc1 -std=c++17 -verify=ref-cxx17 %s |
| |
| #define INT_MIN (~__INT_MAX__) |
| |
| |
| namespace shifts { |
| constexpr void test() { // ref-error {{constexpr function never produces a constant expression}} \ |
| // ref-cxx17-error {{constexpr function never produces a constant expression}} \ |
| // expected-error {{constexpr function never produces a constant expression}} \ |
| // cxx17-error {{constexpr function never produces a constant expression}} \ |
| |
| char c; // cxx17-warning {{uninitialized variable}} \ |
| // ref-cxx17-warning {{uninitialized variable}} |
| |
| c = 0 << 0; |
| c = 0 << 1; |
| c = 1 << 0; |
| c = 1 << -0; |
| c = 1 >> -0; |
| c = 1 << -1; // expected-warning {{shift count is negative}} \ |
| // expected-note {{negative shift count -1}} \ |
| // cxx17-note {{negative shift count -1}} \ |
| // cxx17-warning {{shift count is negative}} \ |
| // ref-warning {{shift count is negative}} \ |
| // ref-note {{negative shift count -1}} \ |
| // ref-cxx17-warning {{shift count is negative}} \ |
| // ref-cxx17-note {{negative shift count -1}} |
| |
| c = 1 >> -1; // expected-warning {{shift count is negative}} \ |
| // cxx17-warning {{shift count is negative}} \ |
| // ref-warning {{shift count is negative}} \ |
| // ref-cxx17-warning {{shift count is negative}} |
| c = 1 << (unsigned)-1; // expected-warning {{shift count >= width of type}} \ |
| // FIXME: 'implicit conversion' warning missing in the new interpreter. \ |
| // cxx17-warning {{shift count >= width of type}} \ |
| // ref-warning {{shift count >= width of type}} \ |
| // ref-warning {{implicit conversion}} \ |
| // ref-cxx17-warning {{shift count >= width of type}} \ |
| // ref-cxx17-warning {{implicit conversion}} |
| c = 1 >> (unsigned)-1; // expected-warning {{shift count >= width of type}} \ |
| // cxx17-warning {{shift count >= width of type}} \ |
| // ref-warning {{shift count >= width of type}} \ |
| // ref-cxx17-warning {{shift count >= width of type}} |
| c = 1 << c; |
| c <<= 0; |
| c >>= 0; |
| c <<= 1; |
| c >>= 1; |
| c <<= -1; // expected-warning {{shift count is negative}} \ |
| // cxx17-warning {{shift count is negative}} \ |
| // ref-warning {{shift count is negative}} \ |
| // ref-cxx17-warning {{shift count is negative}} |
| c >>= -1; // expected-warning {{shift count is negative}} \ |
| // cxx17-warning {{shift count is negative}} \ |
| // ref-warning {{shift count is negative}} \ |
| // ref-cxx17-warning {{shift count is negative}} |
| c <<= 999999; // expected-warning {{shift count >= width of type}} \ |
| // cxx17-warning {{shift count >= width of type}} \ |
| // ref-warning {{shift count >= width of type}} \ |
| // ref-cxx17-warning {{shift count >= width of type}} |
| c >>= 999999; // expected-warning {{shift count >= width of type}} \ |
| // cxx17-warning {{shift count >= width of type}} \ |
| // ref-warning {{shift count >= width of type}} \ |
| // ref-cxx17-warning {{shift count >= width of type}} |
| c <<= __CHAR_BIT__; // expected-warning {{shift count >= width of type}} \ |
| // cxx17-warning {{shift count >= width of type}} \ |
| // ref-warning {{shift count >= width of type}} \ |
| // ref-cxx17-warning {{shift count >= width of type}} |
| c >>= __CHAR_BIT__; // expected-warning {{shift count >= width of type}} \ |
| // cxx17-warning {{shift count >= width of type}} \ |
| // ref-warning {{shift count >= width of type}} \ |
| // ref-cxx17-warning {{shift count >= width of type}} |
| c <<= __CHAR_BIT__+1; // expected-warning {{shift count >= width of type}} \ |
| // cxx17-warning {{shift count >= width of type}} \ |
| // ref-warning {{shift count >= width of type}} \ |
| // ref-cxx17-warning {{shift count >= width of type}} |
| c >>= __CHAR_BIT__+1; // expected-warning {{shift count >= width of type}} \ |
| // cxx17-warning {{shift count >= width of type}} \ |
| // ref-warning {{shift count >= width of type}} \ |
| // ref-cxx17-warning {{shift count >= width of type}} |
| (void)((long)c << __CHAR_BIT__); |
| |
| int i; // cxx17-warning {{uninitialized variable}} \ |
| // ref-cxx17-warning {{uninitialized variable}} |
| i = 1 << (__INT_WIDTH__ - 2); |
| i = 2 << (__INT_WIDTH__ - 1); // cxx17-warning {{bits to represent, but 'int' only has}} \ |
| // ref-cxx17-warning {{bits to represent, but 'int' only has}} |
| i = 1 << (__INT_WIDTH__ - 1); // cxx17-warning-not {{sets the sign bit of the shift expression}} |
| i = -1 << (__INT_WIDTH__ - 1); // cxx17-warning {{shifting a negative signed value is undefined}} \ |
| // ref-cxx17-warning {{shifting a negative signed value is undefined}} |
| i = -1 << 0; // cxx17-warning {{shifting a negative signed value is undefined}} \ |
| // ref-cxx17-warning {{shifting a negative signed value is undefined}} |
| i = 0 << (__INT_WIDTH__ - 1); |
| i = (char)1 << (__INT_WIDTH__ - 2); |
| |
| unsigned u; // cxx17-warning {{uninitialized variable}} \ |
| // ref-cxx17-warning {{uninitialized variable}} |
| u = 1U << (__INT_WIDTH__ - 1); |
| u = 5U << (__INT_WIDTH__ - 1); |
| |
| long long int lli; // cxx17-warning {{uninitialized variable}} \ |
| // ref-cxx17-warning {{uninitialized variable}} |
| lli = INT_MIN << 2; // cxx17-warning {{shifting a negative signed value is undefined}} \ |
| // ref-cxx17-warning {{shifting a negative signed value is undefined}} |
| lli = 1LL << (sizeof(long long) * __CHAR_BIT__ - 2); |
| } |
| |
| static_assert(1 << 4 == 16, ""); |
| constexpr unsigned m = 2 >> 1; |
| static_assert(m == 1, ""); |
| constexpr unsigned char c = 0 << 8; |
| static_assert(c == 0, ""); |
| static_assert(true << 1, ""); |
| static_assert(1 << (__INT_WIDTH__ +1) == 0, ""); // expected-error {{not an integral constant expression}} \ |
| // expected-note {{>= width of type 'int'}} \ |
| // cxx17-error {{not an integral constant expression}} \ |
| // cxx17-note {{>= width of type 'int'}} \ |
| // ref-error {{not an integral constant expression}} \ |
| // ref-note {{>= width of type 'int'}} \ |
| // ref-cxx17-error {{not an integral constant expression}} \ |
| // ref-cxx17-note {{>= width of type 'int'}} |
| |
| constexpr int i1 = 1 << -1; // expected-error {{must be initialized by a constant expression}} \ |
| // expected-note {{negative shift count -1}} \ |
| // cxx17-error {{must be initialized by a constant expression}} \ |
| // cxx17-note {{negative shift count -1}} \ |
| // ref-error {{must be initialized by a constant expression}} \ |
| // ref-note {{negative shift count -1}} \ |
| // ref-cxx17-error {{must be initialized by a constant expression}} \ |
| // ref-cxx17-note {{negative shift count -1}} |
| |
| constexpr int i2 = 1 << (__INT_WIDTH__ + 1); // expected-error {{must be initialized by a constant expression}} \ |
| // expected-note {{>= width of type}} \ |
| // cxx17-error {{must be initialized by a constant expression}} \ |
| // cxx17-note {{>= width of type}} \ |
| // ref-error {{must be initialized by a constant expression}} \ |
| // ref-note {{>= width of type}} \ |
| // ref-cxx17-error {{must be initialized by a constant expression}} \ |
| // ref-cxx17-note {{>= width of type}} |
| |
| constexpr char c2 = 1; |
| constexpr int i3 = c2 << (__CHAR_BIT__ + 1); // Not ill-formed |
| |
| /// The purpose of these few lines is to test that we can shift more bits |
| /// than an unsigned *of the host* has. There was a bug where we casted |
| /// to host-unsigned. However, we cannot query what a host-unsigned even is |
| /// here, so only test this on platforms where `sizeof(long long) > sizeof(unsigned)`. |
| constexpr long long int L = 1; |
| constexpr signed int R = (sizeof(unsigned) * 8) + 1; |
| constexpr decltype(L) M = (R > 32 && R < 64) ? L << R : 0; |
| constexpr decltype(L) M2 = (R > 32 && R < 64) ? L >> R : 0; |
| |
| |
| constexpr int signedShift() { // cxx17-error {{never produces a constant expression}} \ |
| // ref-cxx17-error {{never produces a constant expression}} |
| return 1024 << 31; // cxx17-warning {{signed shift result}} \ |
| // ref-cxx17-warning {{signed shift result}} \ |
| // cxx17-note {{signed left shift discards bits}} \ |
| // ref-cxx17-note {{signed left shift discards bits}} |
| } |
| |
| constexpr int negativeShift() { // cxx17-error {{never produces a constant expression}} \ |
| // ref-cxx17-error {{never produces a constant expression}} |
| return -1 << 2; // cxx17-warning {{shifting a negative signed value is undefined}} \ |
| // ref-cxx17-warning {{shifting a negative signed value is undefined}} \ |
| // cxx17-note {{left shift of negative value -1}} \ |
| // ref-cxx17-note {{left shift of negative value -1}} |
| } |
| |
| constexpr int foo(int a) { |
| return -a << 2; // cxx17-note {{left shift of negative value -10}} \ |
| // ref-cxx17-note {{left shift of negative value -10}} \ |
| // cxx17-note {{left shift of negative value -2}} \ |
| // ref-cxx17-note {{left shift of negative value -2}} |
| } |
| static_assert(foo(10)); // cxx17-error {{not an integral constant expression}} \ |
| // cxx17-note {{in call to 'foo(10)'}} \ |
| // ref-cxx17-error {{not an integral constant expression}} \ |
| // ref-cxx17-note {{in call to 'foo(10)'}} |
| |
| constexpr int a = -2; |
| static_assert(foo(a)); |
| static_assert(foo(-a)); // cxx17-error {{not an integral constant expression}} \ |
| // cxx17-note {{in call to 'foo(2)'}} \ |
| // ref-cxx17-error {{not an integral constant expression}} \ |
| // ref-cxx17-note {{in call to 'foo(2)'}} |
| }; |
