/*
* 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_RUNTIME_BASE_MACROS_H_
#define ART_RUNTIME_BASE_MACROS_H_
#include <stddef.h> // for size_t
#include <unistd.h> // for TEMP_FAILURE_RETRY
// bionic and glibc both have TEMP_FAILURE_RETRY, but eg Mac OS' libc doesn't.
#ifndef TEMP_FAILURE_RETRY
#define TEMP_FAILURE_RETRY(exp) ({ \
decltype(exp) _rc; \
do { \
_rc = (exp); \
} while (_rc == -1 && errno == EINTR); \
_rc; })
#endif
#define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
// C++11 final and override keywords that were introduced in GCC version 4.7.
#if defined(__clang__) || GCC_VERSION >= 40700
#define OVERRIDE override
#define FINAL final
#else
#define OVERRIDE
#define FINAL
#endif
// The COMPILE_ASSERT macro can be used to verify that a compile time
// expression is true. For example, you could use it to verify the
// size of a static array:
//
// COMPILE_ASSERT(ARRAYSIZE(content_type_names) == CONTENT_NUM_TYPES,
// content_type_names_incorrect_size);
//
// or to make sure a struct is smaller than a certain size:
//
// COMPILE_ASSERT(sizeof(foo) < 128, foo_too_large);
//
// The second argument to the macro is the name of the variable. If
// the expression is false, most compilers will issue a warning/error
// containing the name of the variable.
template <bool>
struct CompileAssert {
};
#define COMPILE_ASSERT(expr, msg) \
typedef CompileAssert<(bool(expr))> msg[bool(expr) ? 1 : -1] // NOLINT
// DISALLOW_COPY_AND_ASSIGN disallows the copy and operator= functions.
// It goes in the private: declarations in a class.
#define DISALLOW_COPY_AND_ASSIGN(TypeName) \
TypeName(const TypeName&); \
void operator=(const TypeName&)
// A macro to disallow all the implicit constructors, namely the
// default constructor, copy constructor and operator= functions.
//
// This should be used in the private: declarations for a class
// that wants to prevent anyone from instantiating it. This is
// especially useful for classes containing only static methods.
#define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
TypeName(); \
DISALLOW_COPY_AND_ASSIGN(TypeName)
// The arraysize(arr) macro returns the # of elements in an array arr.
// The expression is a compile-time constant, and therefore can be
// used in defining new arrays, for example. If you use arraysize on
// a pointer by mistake, you will get a compile-time error.
//
// One caveat is that arraysize() doesn't accept any array of an
// anonymous type or a type defined inside a function. In these rare
// cases, you have to use the unsafe ARRAYSIZE_UNSAFE() macro below. This is
// due to a limitation in C++'s template system. The limitation might
// eventually be removed, but it hasn't happened yet.
// This template function declaration is used in defining arraysize.
// Note that the function doesn't need an implementation, as we only
// use its type.
template <typename T, size_t N>
char (&ArraySizeHelper(T (&array)[N]))[N];
#define arraysize(array) (sizeof(ArraySizeHelper(array)))
// ARRAYSIZE_UNSAFE performs essentially the same calculation as arraysize,
// but can be used on anonymous types or types defined inside
// functions. It's less safe than arraysize as it accepts some
// (although not all) pointers. Therefore, you should use arraysize
// whenever possible.
//
// The expression ARRAYSIZE_UNSAFE(a) is a compile-time constant of type
// size_t.
//
// ARRAYSIZE_UNSAFE catches a few type errors. If you see a compiler error
//
// "warning: division by zero in ..."
//
// when using ARRAYSIZE_UNSAFE, you are (wrongfully) giving it a pointer.
// You should only use ARRAYSIZE_UNSAFE on statically allocated arrays.
//
// The following comments are on the implementation details, and can
// be ignored by the users.
//
// ARRAYSIZE_UNSAFE(arr) works by inspecting sizeof(arr) (the # of bytes in
// the array) and sizeof(*(arr)) (the # of bytes in one array
// element). If the former is divisible by the latter, perhaps arr is
// indeed an array, in which case the division result is the # of
// elements in the array. Otherwise, arr cannot possibly be an array,
// and we generate a compiler error to prevent the code from
// compiling.
//
// Since the size of bool is implementation-defined, we need to cast
// !(sizeof(a) & sizeof(*(a))) to size_t in order to ensure the final
// result has type size_t.
//
// This macro is not perfect as it wrongfully accepts certain
// pointers, namely where the pointer size is divisible by the pointee
// size. Since all our code has to go through a 32-bit compiler,
// where a pointer is 4 bytes, this means all pointers to a type whose
// size is 3 or greater than 4 will be (righteously) rejected.
#define ARRAYSIZE_UNSAFE(a) \
((sizeof(a) / sizeof(*(a))) / static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))))
#define SIZEOF_MEMBER(t, f) sizeof((reinterpret_cast<t*>(4096))->f)
#define OFFSETOF_MEMBER(t, f) \
(reinterpret_cast<const char*>(&reinterpret_cast<t*>(16)->f) - reinterpret_cast<const char*>(16)) // NOLINT
#define OFFSETOF_VOLATILE_MEMBER(t, f) \
(reinterpret_cast<volatile char*>(&reinterpret_cast<t*>(16)->f) - reinterpret_cast<volatile char*>(16)) // NOLINT
#define PACKED(x) __attribute__ ((__aligned__(x), __packed__))
#define LIKELY(x) __builtin_expect((x), true)
#define UNLIKELY(x) __builtin_expect((x), false)
// Stringify the argument.
#define QUOTE(x) #x
#define STRINGIFY(x) QUOTE(x)
#ifndef NDEBUG
#define ALWAYS_INLINE
#else
#define ALWAYS_INLINE __attribute__ ((always_inline))
#endif
#ifdef __clang__
/* clang doesn't like attributes on lambda functions */
#define ALWAYS_INLINE_LAMBDA
#else
#define ALWAYS_INLINE_LAMBDA ALWAYS_INLINE
#endif
#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 WARN_UNUSED __attribute__((warn_unused_result))
template<typename T> void UNUSED(const T&) {}
// Annotalysis thread-safety analysis support.
#if defined(__SUPPORT_TS_ANNOTATION__) || defined(__clang__)
#define THREAD_ANNOTATION_ATTRIBUTE__(x) __attribute__((x))
#else
#define THREAD_ANNOTATION_ATTRIBUTE__(x) // no-op
#endif
#define ACQUIRED_AFTER(...) THREAD_ANNOTATION_ATTRIBUTE__(acquired_after(__VA_ARGS__))
#define ACQUIRED_BEFORE(...) THREAD_ANNOTATION_ATTRIBUTE__(acquired_before(__VA_ARGS__))
#define EXCLUSIVE_LOCKS_REQUIRED(...) THREAD_ANNOTATION_ATTRIBUTE__(exclusive_locks_required(__VA_ARGS__))
#define GUARDED_BY(x) THREAD_ANNOTATION_ATTRIBUTE__(guarded_by(x))
#define GUARDED_VAR THREAD_ANNOTATION_ATTRIBUTE__(guarded)
#define LOCKABLE THREAD_ANNOTATION_ATTRIBUTE__(lockable)
#define LOCK_RETURNED(x) THREAD_ANNOTATION_ATTRIBUTE__(lock_returned(x))
#define LOCKS_EXCLUDED(...) THREAD_ANNOTATION_ATTRIBUTE__(locks_excluded(__VA_ARGS__))
#define NO_THREAD_SAFETY_ANALYSIS THREAD_ANNOTATION_ATTRIBUTE__(no_thread_safety_analysis)
#define PT_GUARDED_BY(x)
// THREAD_ANNOTATION_ATTRIBUTE__(point_to_guarded_by(x))
#define PT_GUARDED_VAR THREAD_ANNOTATION_ATTRIBUTE__(point_to_guarded)
#define SCOPED_LOCKABLE THREAD_ANNOTATION_ATTRIBUTE__(scoped_lockable)
#define SHARED_LOCKS_REQUIRED(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_locks_required(__VA_ARGS__))
#if defined(__clang__)
#define EXCLUSIVE_LOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(exclusive_lock_function(__VA_ARGS__))
#define EXCLUSIVE_TRYLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(exclusive_trylock_function(__VA_ARGS__))
#define SHARED_LOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_lock_function(__VA_ARGS__))
#define SHARED_TRYLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_trylock_function(__VA_ARGS__))
#define UNLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(unlock_function(__VA_ARGS__))
#else
#define EXCLUSIVE_LOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(exclusive_lock(__VA_ARGS__))
#define EXCLUSIVE_TRYLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(exclusive_trylock(__VA_ARGS__))
#define SHARED_LOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_lock(__VA_ARGS__))
#define SHARED_TRYLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_trylock(__VA_ARGS__))
#define UNLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(unlock(__VA_ARGS__))
#endif
#endif // ART_RUNTIME_BASE_MACROS_H_