| // Copyright 2017 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_DAWN_COMMON_COMPILER_H_ | |
| #define SRC_DAWN_COMMON_COMPILER_H_ | |
| #include "src/utils/compiler.h" | |
| // Defines macros for compiler-specific functionality | |
| // DAWN_UNUSED_FUNC | |
| // | |
| // Prevents unused variable/expression warnings on FUNC. | |
| #define DAWN_UNUSED_FUNC(FUNC) static_assert(sizeof(&FUNC) == sizeof(void (*)())) | |
| // DAWN_FORCE_INLINE | |
| // | |
| // Annotate a function indicating it should really never be inline, even in debug mode. | |
| #if DAWN_COMPILER_IS(CLANG) && defined(NDEBUG) && DAWN_HAS_CPP_ATTRIBUTE(clang::always_inline) | |
| #define DAWN_FORCE_INLINE [[clang::always_inline]] inline | |
| #elif DAWN_COMPILER_IS(GCC) && defined(NDEBUG) && DAWN_HAS_ATTRIBUTE(always_inline) | |
| #define DAWN_FORCE_INLINE inline __attribute__((always_inline)) | |
| #elif DAWN_COMPILER_IS(MSVC) && defined(NDEBUG) | |
| #define DAWN_FORCE_INLINE __forceinline | |
| #else | |
| #define DAWN_FORCE_INLINE inline | |
| #endif | |
| // DAWN_TRIVIAL_ABI | |
| // | |
| // Marks a type as being eligible for the "trivial" ABI despite having a | |
| // non-trivial destructor or copy/move constructor. Such types can be relocated | |
| // after construction by simply copying their memory, which makes them eligible | |
| // to be passed in registers. The canonical example is std::unique_ptr. | |
| // | |
| // Use with caution; this has some subtle effects on constructor/destructor | |
| // ordering and will be very incorrect if the type relies on its address | |
| // remaining constant. When used as a function argument (by value), the value | |
| // may be constructed in the caller's stack frame, passed in a register, and | |
| // then used and destructed in the callee's stack frame. A similar thing can | |
| // occur when values are returned. | |
| // | |
| // TRIVIAL_ABI is not needed for types which have a trivial destructor and | |
| // copy/move constructors, such as base::TimeTicks and other POD. | |
| // | |
| // It is also not likely to be effective on types too large to be passed in one | |
| // or two registers on typical target ABIs. | |
| // | |
| // See also: | |
| // https://clang.llvm.org/docs/AttributeReference.html#trivial-abi | |
| // https://libcxx.llvm.org/docs/DesignDocs/UniquePtrTrivialAbi.html | |
| #if DAWN_COMPILER_IS(CLANG) && DAWN_HAS_ATTRIBUTE(trivial_abi) | |
| #define DAWN_TRIVIAL_ABI [[clang::trivial_abi]] | |
| #else | |
| #define DAWN_TRIVIAL_ABI | |
| #endif | |
| // DAWN_CONSTINIT | |
| // | |
| // Requires constant initialization. See constinit in C++20. Allows to rely on a variable being | |
| // initialized before execution, and not requiring a global constructor. | |
| #if DAWN_HAS_ATTRIBUTE(require_constant_initialization) | |
| #define DAWN_CONSTINIT __attribute__((require_constant_initialization)) | |
| #else | |
| #define DAWN_CONSTINIT | |
| #endif | |
| // DAWN_GSL_POINTER | |
| // | |
| // In [lifetime safety], If you write a custom class wrapping a pointer, the [[gsl::Owner]] and | |
| // [[gsl::Pointer]] can help the compiler to know if it acquired ownership over the pointee, or not. | |
| // The compiler is then able to emit useful warning. | |
| // | |
| // [lifetime safety]: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1179r0.pdf | |
| #if DAWN_COMPILER_IS(CLANG) | |
| #define DAWN_GSL_POINTER [[gsl::Pointer]] | |
| #else | |
| #define DAWN_GSL_POINTER | |
| #endif | |
| // DAWN_CONSTEXPR_DTOR | |
| // | |
| // Constexpr destructors were introduced in C++20. Dawn's minimum supported C++ version is C++17. | |
| #if defined(__cpp_constexpr) && __cpp_constexpr >= 201907L | |
| #define DAWN_CONSTEXPR_DTOR constexpr | |
| #else | |
| #define DAWN_CONSTEXPR_DTOR | |
| #endif | |
| // DAWN_ATTRIBUTE_RETURNS_NONNULL | |
| // | |
| // Tells the compiler that a function never returns a null pointer. Sourced from Abseil's | |
| // `attributes.h`. | |
| #if DAWN_HAS_ATTRIBUTE(returns_nonnull) | |
| #define DAWN_ATTRIBUTE_RETURNS_NONNULL __attribute__((returns_nonnull)) | |
| #else | |
| #define DAWN_ATTRIBUTE_RETURNS_NONNULL | |
| #endif | |
| #endif // SRC_DAWN_COMMON_COMPILER_H_ |