38 lines · cpp
1// RUN: %clang_cc1 -fms-compatibility -fms-compatibility-version=19.33 -std=c++20 -verify %s2 3[[msvc::constexpr]] int log2(int x) { [[msvc::constexpr]] return x > 1 ? 1 + log2(x / 2) : 0; }4constexpr bool test_log2() { [[msvc::constexpr]] return log2(32) == 5; }5static_assert(test_log2());6 7[[msvc::constexpr]] int get_value(int x)8{9 switch (x)10 {11 case 42: return 1337;12 default:13 if (x < 0) [[msvc::constexpr]] return log2(-x);14 else return x;15 }16}17 18constexpr bool test_complex_expr() {19 [[msvc::constexpr]] return get_value(get_value(42) - 1337 + get_value(-32) - 5 + (get_value(1) ? get_value(0) : get_value(2))) == get_value(0);20}21static_assert(test_complex_expr());22 23constexpr bool get_constexpr_true() { return true; }24[[msvc::constexpr]] bool get_msconstexpr_true() { return get_constexpr_true(); }25constexpr bool test_get_msconstexpr_true() { [[msvc::constexpr]] return get_msconstexpr_true(); }26static_assert(test_get_msconstexpr_true());27 28// TODO (#72149): Add support for [[msvc::constexpr]] constructor; this code is valid for MSVC.29struct S2 {30 [[msvc::constexpr]] S2() {}31 [[msvc::constexpr]] bool value() { return true; }32 static constexpr bool check() { [[msvc::constexpr]] return S2{}.value(); } // expected-error {{constexpr function never produces a constant expression}} \33 // expected-note {{non-literal type 'S2' cannot be used in a constant expression}} \34 // expected-note {{non-literal type 'S2' cannot be used in a constant expression}}35};36static_assert(S2::check()); // expected-error {{static assertion expression is not an integral constant expression}} \37 // expected-note {{in call to 'check()'}}38