| // 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_ |
