libartbase/base/macros.h

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ART_LIBARTBASE_BASE_MACROS_H_
#define ART_LIBARTBASE_BASE_MACROS_H_

#include <stddef.h>  // for size_t
#include <unistd.h>  // for TEMP_FAILURE_RETRY

#include "android-base/format.h"
#include "android-base/macros.h"
#include "android-base/thread_annotations.h"

// Declare a friend relationship in a class with a test. Used rather that FRIEND_TEST to avoid
// globally importing gtest/gtest.h into the main ART header files.
#define ART_FRIEND_TEST(test_set_name, individual_test)\
friend class test_set_name##_##individual_test##_Test

// Declare a friend relationship in a class with a typed test.
#define ART_FRIEND_TYPED_TEST(test_set_name, individual_test)\
template<typename T> ART_FRIEND_TEST(test_set_name, individual_test)

// Shorthand for formatting with compile time checking of the format string
#define ART_FORMAT(str, ...) ::fmt::format(FMT_STRING(str), __VA_ARGS__)

// A macro to disallow new and delete operators for a class. It goes in the private: declarations.
// NOTE: Providing placement new (and matching delete) for constructing container elements.
#define DISALLOW_ALLOCATION() \
  public: \
    NO_RETURN ALWAYS_INLINE void operator delete(void*, size_t) { UNREACHABLE(); } \
    ALWAYS_INLINE void* operator new(size_t, void* ptr) noexcept { return ptr; } \
    ALWAYS_INLINE void operator delete(void*, void*) noexcept { } \
  private: \
    void* operator new(size_t) = delete  // NOLINT

// offsetof is not defined by the spec on types with non-standard layout,
// however it is implemented by compilers in practice.
// (note that reinterpret_cast is not valid constexpr)
//
// Alternative approach would be something like:
// #define OFFSETOF_HELPER(t, f) \
//   (reinterpret_cast<uintptr_t>(&reinterpret_cast<t*>(16)->f) - static_cast<uintptr_t>(16u))
// #define OFFSETOF_MEMBER(t, f) \
//   (__builtin_constant_p(OFFSETOF_HELPER(t,f)) ? OFFSETOF_HELPER(t,f) : OFFSETOF_HELPER(t,f))
#define OFFSETOF_MEMBER(t, f) offsetof(t, f)

#define OFFSETOF_MEMBERPTR(t, f) \
  (reinterpret_cast<uintptr_t>(&(reinterpret_cast<t*>(16)->*f)) - static_cast<uintptr_t>(16))  // NOLINT

#define ALIGNED(x) __attribute__ ((__aligned__(x)))
#define PACKED(x) __attribute__ ((__aligned__(x), __packed__))

// Stringify the argument.
#define QUOTE(x) #x
#define STRINGIFY(x) QUOTE(x)

// Append tokens after evaluating.
#define APPEND_TOKENS_AFTER_EVAL_2(a, b) a ## b
#define APPEND_TOKENS_AFTER_EVAL(a, b) APPEND_TOKENS_AFTER_EVAL_2(a, b)

#ifndef NDEBUG
#define ALWAYS_INLINE
#define FLATTEN
#else
#define ALWAYS_INLINE  __attribute__ ((always_inline))
#define FLATTEN  __attribute__ ((flatten))
#endif

#define NO_STACK_PROTECTOR __attribute__ ((no_stack_protector))

// clang doesn't like attributes on lambda functions. It would be nice to say:
//   #define ALWAYS_INLINE_LAMBDA ALWAYS_INLINE
#define ALWAYS_INLINE_LAMBDA

#define NO_INLINE __attribute__ ((noinline))

#if defined (__APPLE__)
#define HOT_ATTR
#define COLD_ATTR
#else
#define HOT_ATTR __attribute__ ((hot))
#define COLD_ATTR __attribute__ ((cold))
#endif

#define PURE __attribute__ ((__pure__))

// Define that a position within code is unreachable, for example:
//   int foo () { LOG(FATAL) << "Don't call me"; UNREACHABLE(); }
// without the UNREACHABLE a return statement would be necessary.
#define UNREACHABLE  __builtin_unreachable

// Add the C++11 noreturn attribute.
#define NO_RETURN [[ noreturn ]]  // NOLINT[whitespace/braces] [5]

// Annotalysis thread-safety analysis support. Things that are not in base.

#define LOCKABLE CAPABILITY("mutex")
#define SHARED_LOCKABLE SHARED_CAPABILITY("mutex")

// Some of the libs (e.g. libarttest(d)) require more public symbols when built
// in debug configuration.
// Using symbol visibility only for release builds allows to reduce the list of
// exported symbols and eliminates the need to check debug build configurations
// when changing the exported symbols.
#ifdef NDEBUG
#define HIDDEN __attribute__((visibility("hidden")))
#define PROTECTED __attribute__((visibility("protected")))
#define EXPORT __attribute__((visibility("default")))
#else
#define HIDDEN
#define PROTECTED
#define EXPORT
#endif

// Protected symbols must be declared with "protected" visibility attribute when
// building the library and "default" visibility when referred to from external
// libraries/binaries. Otherwise, the external code will expect the symbol to be
// defined locally and fail to link.
#ifdef BUILDING_LIBART
#define LIBART_PROTECTED PROTECTED
#else
#define LIBART_PROTECTED EXPORT
#endif

// Some global variables shouldn't be visible outside libraries declaring them.
// The attribute allows hiding them, so preventing direct access.
#define ALWAYS_HIDDEN __attribute__((visibility("hidden")))

#endif  // ART_LIBARTBASE_BASE_MACROS_H_