src/dawn/common/Compiler.h - dawn.git - Git at Google

 // 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

 // DAWN_ENABLE_STRUCT_PADDING_WARNINGS
 //
 // Tells the compiler to emit a warning if the structure has any padding.
 // This is helpful to avoid uninitialized bits in cache keys or other similar structures.
 #if DAWN_COMPILER_IS(CLANG)
 #define DAWN_ENABLE_STRUCT_PADDING_WARNINGS \
     _Pragma("clang diagnostic push") _Pragma("clang diagnostic error \"-Wpadded\"")
 #define DAWN_DISABLE_STRUCT_PADDING_WARNINGS _Pragma("clang diagnostic pop")
 #elif DAWN_COMPILER_IS(GCC)
 #define DAWN_ENABLE_STRUCT_PADDING_WARNINGS \
     _Pragma("GCC diagnostic push") _Pragma("GCC diagnostic error \"-Wpadded\"")
 #define DAWN_DISABLE_STRUCT_PADDING_WARNINGS _Pragma("GCC diagnostic pop")
 #elif DAWN_COMPILER_IS(MSVC)
 #define DAWN_ENABLE_STRUCT_PADDING_WARNINGS __pragma(warning(push)) __pragma(warning(error : 4820))
 #define DAWN_DISABLE_STRUCT_PADDING_WARNINGS __pragma(warning(pop))
 #else
 #define DAWN_ENABLE_STRUCT_PADDING_WARNINGS
 #define DAWN_DISABLE_STRUCT_PADDING_WARNINGS
 #endif

 // DAWN_MUTEX_CAPABILITY
 //
 // Used when a class provides a mutex capability for thread-safety analysis.
 //
 // https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#capability-string
 #if DAWN_HAS_ATTRIBUTE(capability)
 #define DAWN_MUTEX_CAPABILITY __attribute__((capability("mutex")))
 #else
 #define DAWN_MUTEX_CAPABILITY
 #endif

 // DAWN_SCOPED_LOCKABLE
 //
 // Used when a class implements RAII-style locking.
 //
 // https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#scoped-capability
 #if DAWN_HAS_ATTRIBUTE(scoped_lockable)
 #define DAWN_SCOPED_LOCKABLE __attribute__((scoped_lockable))
 #else
 #define DAWN_SCOPED_LOCKABLE
 #endif

 // DAWN_EXCLUSIVE_LOCK_FUNCTION
 //
 // Used when a function acquires a lock. The lock must not be in the acquired state at the beginning
 // of the function and must be in the acquired state at the end of the function.
 //
 // https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#acquire-acquire-shared-release-release-shared-release-generic
 #if DAWN_HAS_ATTRIBUTE(exclusive_lock_function)
 #define DAWN_EXCLUSIVE_LOCK_FUNCTION __attribute__((exclusive_lock_function()))
 #else
 #define DAWN_EXCLUSIVE_LOCK_FUNCTION
 #endif

 // DAWN_UNLOCK_FUNCTION
 //
 // Used when a function releases a lock. The lock must be in the acquired state at the beginning of
 // the function and must be in the released state at the end of the function.
 //
 // https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#acquire-acquire-shared-release-release-shared-release-generic
 #if DAWN_HAS_ATTRIBUTE(unlock_function)
 #define DAWN_UNLOCK_FUNCTION __attribute__((unlock_function()))
 #else
 #define DAWN_UNLOCK_FUNCTION
 #endif

 // DAWN_NO_THREAD_SAFETY_ANALYSIS
 //
 // Used when a function is too complicated for the thread safety static
 // analysis, and the compiler generates spurious warnings. Use this sparingly.
 // For example, Clang does not know how to analyze conditionally-held locks, and
 // may generate spurious warnings.
 //
 // Place this macro just before the opening brace of the function *definition*.
 // Do not put it at the declaration.
 //
 // https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#no-thread-safety-analysis
 #if DAWN_HAS_ATTRIBUTE(no_thread_safety_analysis)
 #define DAWN_NO_THREAD_SAFETY_ANALYSIS __attribute__((no_thread_safety_analysis))
 #else
 #define DAWN_NO_THREAD_SAFETY_ANALYSIS
 #endif

 #endif  // SRC_DAWN_COMMON_COMPILER_H_
	// 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

	// DAWN_ENABLE_STRUCT_PADDING_WARNINGS
	//
	// Tells the compiler to emit a warning if the structure has any padding.
	// This is helpful to avoid uninitialized bits in cache keys or other similar structures.
	#if DAWN_COMPILER_IS(CLANG)
	#define DAWN_ENABLE_STRUCT_PADDING_WARNINGS \
	_Pragma("clang diagnostic push") _Pragma("clang diagnostic error \"-Wpadded\"")
	#define DAWN_DISABLE_STRUCT_PADDING_WARNINGS _Pragma("clang diagnostic pop")
	#elif DAWN_COMPILER_IS(GCC)
	#define DAWN_ENABLE_STRUCT_PADDING_WARNINGS \
	_Pragma("GCC diagnostic push") _Pragma("GCC diagnostic error \"-Wpadded\"")
	#define DAWN_DISABLE_STRUCT_PADDING_WARNINGS _Pragma("GCC diagnostic pop")
	#elif DAWN_COMPILER_IS(MSVC)
	#define DAWN_ENABLE_STRUCT_PADDING_WARNINGS __pragma(warning(push)) __pragma(warning(error : 4820))
	#define DAWN_DISABLE_STRUCT_PADDING_WARNINGS __pragma(warning(pop))
	#else
	#define DAWN_ENABLE_STRUCT_PADDING_WARNINGS
	#define DAWN_DISABLE_STRUCT_PADDING_WARNINGS
	#endif

	// DAWN_MUTEX_CAPABILITY
	//
	// Used when a class provides a mutex capability for thread-safety analysis.
	//
	// https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#capability-string
	#if DAWN_HAS_ATTRIBUTE(capability)
	#define DAWN_MUTEX_CAPABILITY __attribute__((capability("mutex")))
	#else
	#define DAWN_MUTEX_CAPABILITY
	#endif

	// DAWN_SCOPED_LOCKABLE
	//
	// Used when a class implements RAII-style locking.
	//
	// https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#scoped-capability
	#if DAWN_HAS_ATTRIBUTE(scoped_lockable)
	#define DAWN_SCOPED_LOCKABLE __attribute__((scoped_lockable))
	#else
	#define DAWN_SCOPED_LOCKABLE
	#endif

	// DAWN_EXCLUSIVE_LOCK_FUNCTION
	//
	// Used when a function acquires a lock. The lock must not be in the acquired state at the beginning
	// of the function and must be in the acquired state at the end of the function.
	//
	// https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#acquire-acquire-shared-release-release-shared-release-generic
	#if DAWN_HAS_ATTRIBUTE(exclusive_lock_function)
	#define DAWN_EXCLUSIVE_LOCK_FUNCTION __attribute__((exclusive_lock_function()))
	#else
	#define DAWN_EXCLUSIVE_LOCK_FUNCTION
	#endif

	// DAWN_UNLOCK_FUNCTION
	//
	// Used when a function releases a lock. The lock must be in the acquired state at the beginning of
	// the function and must be in the released state at the end of the function.
	//
	// https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#acquire-acquire-shared-release-release-shared-release-generic
	#if DAWN_HAS_ATTRIBUTE(unlock_function)
	#define DAWN_UNLOCK_FUNCTION __attribute__((unlock_function()))
	#else
	#define DAWN_UNLOCK_FUNCTION
	#endif

	// DAWN_NO_THREAD_SAFETY_ANALYSIS
	//
	// Used when a function is too complicated for the thread safety static
	// analysis, and the compiler generates spurious warnings. Use this sparingly.
	// For example, Clang does not know how to analyze conditionally-held locks, and
	// may generate spurious warnings.
	//
	// Place this macro just before the opening brace of the function definition.
	// Do not put it at the declaration.
	//
	// https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#no-thread-safety-analysis
	#if DAWN_HAS_ATTRIBUTE(no_thread_safety_analysis)
	#define DAWN_NO_THREAD_SAFETY_ANALYSIS __attribute__((no_thread_safety_analysis))
	#else
	#define DAWN_NO_THREAD_SAFETY_ANALYSIS
	#endif

	#endif // SRC_DAWN_COMMON_COMPILER_H_