| // Copyright 2024 The Dawn & Tint Authors |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // 1. Redistributions of source code must retain the above copyright notice, this |
| // list of conditions and the following disclaimer. |
| // |
| // 2. Redistributions in binary form must reproduce the above copyright notice, |
| // this list of conditions and the following disclaimer in the documentation |
| // and/or other materials provided with the distribution. |
| // |
| // 3. Neither the name of the copyright holder nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE |
| // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #ifndef SRC_UTILS_COMPILER_H_ |
| #define SRC_UTILS_COMPILER_H_ |
| |
| // DAWN_COMPILER_IS(CLANG|GCC|MSVC): Compiler detection |
| // |
| // Note: clang masquerades as GCC on POSIX and as MSVC on Windows. It must be checked first. |
| #if defined(__clang__) |
| #define DAWN_COMPILER_IS_CLANG 1 |
| #define DAWN_COMPILER_IS_GCC 0 |
| #define DAWN_COMPILER_IS_MSVC 0 |
| #elif defined(__GNUC__) |
| #define DAWN_COMPILER_IS_CLANG 0 |
| #define DAWN_COMPILER_IS_GCC 1 |
| #define DAWN_COMPILER_IS_MSVC 0 |
| #elif defined(_MSC_VER) |
| #define DAWN_COMPILER_IS_CLANG 0 |
| #define DAWN_COMPILER_IS_GCC 0 |
| #define DAWN_COMPILER_IS_MSVC 1 |
| #else |
| #error "Unsupported compiler" |
| #endif |
| |
| // Use #if DAWN_COMPILER_IS(XXX) for compiler specific code. |
| // Do not use #ifdef or the naked macro DAWN_COMPILER_IS_XXX. |
| // This can help avoid common mistakes like not including "compiler.h" and falling into unwanted |
| // code block as usage of undefined macro "function" will be blocked by the compiler. |
| #define DAWN_COMPILER_IS(X) (1 == DAWN_COMPILER_IS_##X) |
| |
| // DAWN_HAS_ATTRIBUTE |
| // |
| // A wrapper around `__has_attribute`. This test whether its operand is recognized by the compiler. |
| #if defined(__has_attribute) |
| #define DAWN_HAS_ATTRIBUTE(x) __has_attribute(x) |
| #else |
| #define DAWN_HAS_ATTRIBUTE(x) 0 |
| #endif |
| |
| // DAWN_HAS_CPP_ATTRIBUTE |
| // |
| // A wrapper around `__has_cpp_attribute`. This test whether its operand is recognized by the |
| // compiler. |
| #if defined(__has_cpp_attribute) |
| #define DAWN_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x) |
| #else |
| #define DAWN_HAS_CPP_ATTRIBUTE(x) 0 |
| #endif |
| |
| // DAWN_BUILTIN_UNREACHABLE() |
| // |
| // Hints the compiler that a code path is unreachable. |
| #if DAWN_COMPILER_IS(MSVC) |
| #define DAWN_BUILTIN_UNREACHABLE() __assume(false) |
| #else |
| #define DAWN_BUILTIN_UNREACHABLE() __builtin_unreachable() |
| #endif |
| |
| // DAWN_LIKELY(EXPR) |
| // |
| // Where available, hints the compiler that the expression will be true to help it generate code |
| // that leads to better branch prediction. |
| #if DAWN_COMPILER_IS(GCC) || DAWN_COMPILER_IS(CLANG) |
| #define DAWN_LIKELY(x) __builtin_expect(!!(x), 1) |
| #else |
| #define DAWN_LIKELY(x) (x) |
| #endif |
| |
| // DAWN_UNLIKELY(EXPR) |
| // |
| // Where available, hints the compiler that the expression will be false to help it generate code |
| // that leads to better branch prediction. |
| #if DAWN_COMPILER_IS(GCC) || DAWN_COMPILER_IS(CLANG) |
| #define DAWN_UNLIKELY(x) __builtin_expect(!!(x), 0) |
| #else |
| #define DAWN_UNLIKELY(x) (x) |
| #endif |
| |
| // DAWN_NO_SANITIZE(instrumentation) |
| // |
| // Annotate a function or a global variable declaration to specify that a particular instrumentation |
| // or set of instrumentations should not be applied. |
| #if DAWN_HAS_ATTRIBUTE(no_sanitize) |
| #define DAWN_NO_SANITIZE(instrumentation) __attribute__((no_sanitize(instrumentation))) |
| #else |
| #define DAWN_NO_SANITIZE(instrumentation) |
| #endif |
| |
| #endif // SRC_UTILS_COMPILER_H_ |
