rocksdb/port/lang.h

98 lines
2.9 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#ifndef FALLTHROUGH_INTENDED
#if defined(__clang__)
#define FALLTHROUGH_INTENDED [[clang::fallthrough]]
#elif defined(__GNUC__) && __GNUC__ >= 7
#define FALLTHROUGH_INTENDED [[gnu::fallthrough]]
#else
#define FALLTHROUGH_INTENDED \
do { \
} while (0)
#endif
#endif
#define DECLARE_DEFAULT_MOVES(Name) \
Name(Name&&) noexcept = default; \
Name& operator=(Name&&) = default
// ASAN (Address sanitizer)
#if defined(__clang__)
#if defined(__has_feature)
#if __has_feature(address_sanitizer)
#define MUST_FREE_HEAP_ALLOCATIONS 1
#endif // __has_feature(address_sanitizer)
#endif // defined(__has_feature)
#else // __clang__
#ifdef __SANITIZE_ADDRESS__
#define MUST_FREE_HEAP_ALLOCATIONS 1
#endif // __SANITIZE_ADDRESS__
#endif // __clang__
#ifdef ROCKSDB_VALGRIND_RUN
#define MUST_FREE_HEAP_ALLOCATIONS 1
#endif // ROCKSDB_VALGRIND_RUN
// Coding guidelines say to avoid static objects with non-trivial destructors,
// because it's easy to cause trouble (UB) in static destruction. This
// macro makes it easier to define static objects that are normally never
// destructed, except are destructed when running under ASAN. This should
// avoid unexpected, unnecessary destruction behavior in production.
// Note that constructor arguments can be provided as in
// STATIC_AVOID_DESTRUCTION(Foo, foo)(arg1, arg2);
#ifdef MUST_FREE_HEAP_ALLOCATIONS
#define STATIC_AVOID_DESTRUCTION(Type, name) static Type name
constexpr bool kMustFreeHeapAllocations = true;
#else
#define STATIC_AVOID_DESTRUCTION(Type, name) static Type& name = *new Type
constexpr bool kMustFreeHeapAllocations = false;
#endif
// TSAN (Thread sanitizer)
// For simplicity, standardize on the GCC define
#if defined(__clang__)
#if defined(__has_feature) && __has_feature(thread_sanitizer)
#define __SANITIZE_THREAD__ 1
#endif // __has_feature(thread_sanitizer)
#endif // __clang__
#ifdef __SANITIZE_THREAD__
#define TSAN_SUPPRESSION __attribute__((no_sanitize("thread")))
#else
#define TSAN_SUPPRESSION
#endif // TSAN_SUPPRESSION
// Compile-time CPU feature testing compatibility
//
// A way to be extra sure these defines have been included.
#define ASSERT_FEATURE_COMPAT_HEADER() static_assert(true, "Semicolon required") /* empty */
// MSVC doesn't support the same defines that gcc and clang provide
// but does some like __AVX__. Here we can infer some features from others.
#ifdef __AVX__
#define __SSE4_2__ 1
#define __PCLMUL__ 1
#endif // __AVX__
// A way to disable PCLMUL
#ifdef NO_PCLMUL
#undef __PCLMUL__
#endif
// popcnt is generally implied by SSE4.2
#if defined(__SSE4_2__)
#define __POPCNT__ 1
#endif
// A way to disable POPCNT
#ifdef NO_POPCNT
#undef __POPCNT__
#endif