1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ART_RUNTIME_BASE_MACROS_H_
18#define ART_RUNTIME_BASE_MACROS_H_
19
20#include <stddef.h>  // for size_t
21#include <unistd.h>  // for TEMP_FAILURE_RETRY
22
23// bionic and glibc both have TEMP_FAILURE_RETRY, but eg Mac OS' libc doesn't.
24#ifndef TEMP_FAILURE_RETRY
25#define TEMP_FAILURE_RETRY(exp) ({ \
26  decltype(exp) _rc; \
27  do { \
28    _rc = (exp); \
29  } while (_rc == -1 && errno == EINTR); \
30  _rc; })
31#endif
32
33#define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
34
35// C++11 final and override keywords that were introduced in GCC version 4.7.
36#if defined(__clang__) || GCC_VERSION >= 40700
37#define OVERRIDE override
38#define FINAL final
39#else
40#define OVERRIDE
41#define FINAL
42#endif
43
44// Declare a friend relationship in a class with a test. Used rather that FRIEND_TEST to avoid
45// globally importing gtest/gtest.h into the main ART header files.
46#define ART_FRIEND_TEST(test_set_name, individual_test)\
47friend class test_set_name##_##individual_test##_Test
48
49// Declare a friend relationship in a class with a typed test.
50#define ART_FRIEND_TYPED_TEST(test_set_name, individual_test)\
51template<typename T> ART_FRIEND_TEST(test_set_name, individual_test)
52
53// DISALLOW_COPY_AND_ASSIGN disallows the copy and operator= functions. It goes in the private:
54// declarations in a class.
55#if !defined(DISALLOW_COPY_AND_ASSIGN)
56#define DISALLOW_COPY_AND_ASSIGN(TypeName) \
57  TypeName(const TypeName&) = delete;  \
58  void operator=(const TypeName&) = delete
59#endif
60
61// A macro to disallow all the implicit constructors, namely the default constructor, copy
62// constructor and operator= functions.
63//
64// This should be used in the private: declarations for a class that wants to prevent anyone from
65// instantiating it. This is especially useful for classes containing only static methods.
66#define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
67  TypeName() = delete;  \
68  DISALLOW_COPY_AND_ASSIGN(TypeName)
69
70// A macro to disallow new and delete operators for a class. It goes in the private: declarations.
71// NOTE: Providing placement new (and matching delete) for constructing container elements.
72#define DISALLOW_ALLOCATION() \
73  public: \
74    NO_RETURN ALWAYS_INLINE void operator delete(void*, size_t) { UNREACHABLE(); } \
75    ALWAYS_INLINE void* operator new(size_t, void* ptr) noexcept { return ptr; } \
76    ALWAYS_INLINE void operator delete(void*, void*) noexcept { } \
77  private: \
78    void* operator new(size_t) = delete
79
80// The arraysize(arr) macro returns the # of elements in an array arr.
81// The expression is a compile-time constant, and therefore can be
82// used in defining new arrays, for example.  If you use arraysize on
83// a pointer by mistake, you will get a compile-time error.
84//
85// One caveat is that arraysize() doesn't accept any array of an
86// anonymous type or a type defined inside a function.  In these rare
87// cases, you have to use the unsafe ARRAYSIZE_UNSAFE() macro below.  This is
88// due to a limitation in C++'s template system.  The limitation might
89// eventually be removed, but it hasn't happened yet.
90
91// This template function declaration is used in defining arraysize.
92// Note that the function doesn't need an implementation, as we only
93// use its type.
94template <typename T, size_t N>
95char (&ArraySizeHelper(T (&array)[N]))[N];
96
97#define arraysize(array) (sizeof(ArraySizeHelper(array)))
98
99// ARRAYSIZE_UNSAFE performs essentially the same calculation as arraysize,
100// but can be used on anonymous types or types defined inside
101// functions.  It's less safe than arraysize as it accepts some
102// (although not all) pointers.  Therefore, you should use arraysize
103// whenever possible.
104//
105// The expression ARRAYSIZE_UNSAFE(a) is a compile-time constant of type
106// size_t.
107//
108// ARRAYSIZE_UNSAFE catches a few type errors.  If you see a compiler error
109//
110//   "warning: division by zero in ..."
111//
112// when using ARRAYSIZE_UNSAFE, you are (wrongfully) giving it a pointer.
113// You should only use ARRAYSIZE_UNSAFE on statically allocated arrays.
114//
115// The following comments are on the implementation details, and can
116// be ignored by the users.
117//
118// ARRAYSIZE_UNSAFE(arr) works by inspecting sizeof(arr) (the # of bytes in
119// the array) and sizeof(*(arr)) (the # of bytes in one array
120// element).  If the former is divisible by the latter, perhaps arr is
121// indeed an array, in which case the division result is the # of
122// elements in the array.  Otherwise, arr cannot possibly be an array,
123// and we generate a compiler error to prevent the code from
124// compiling.
125//
126// Since the size of bool is implementation-defined, we need to cast
127// !(sizeof(a) & sizeof(*(a))) to size_t in order to ensure the final
128// result has type size_t.
129//
130// This macro is not perfect as it wrongfully accepts certain
131// pointers, namely where the pointer size is divisible by the pointee
132// size.  Since all our code has to go through a 32-bit compiler,
133// where a pointer is 4 bytes, this means all pointers to a type whose
134// size is 3 or greater than 4 will be (righteously) rejected.
135#define ARRAYSIZE_UNSAFE(a) \
136  ((sizeof(a) / sizeof(*(a))) / static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))))
137
138#define SIZEOF_MEMBER(t, f) sizeof((reinterpret_cast<t*>(4096))->f)
139
140#define OFFSETOF_MEMBER(t, f) \
141  (reinterpret_cast<uintptr_t>(&reinterpret_cast<t*>(16)->f) - static_cast<uintptr_t>(16u)) // NOLINT
142
143#define OFFSETOF_MEMBERPTR(t, f) \
144  (reinterpret_cast<uintptr_t>(&(reinterpret_cast<t*>(16)->*f)) - static_cast<uintptr_t>(16)) // NOLINT
145
146#define PACKED(x) __attribute__ ((__aligned__(x), __packed__))
147
148#define LIKELY(x)       __builtin_expect((x), true)
149#define UNLIKELY(x)     __builtin_expect((x), false)
150
151// Stringify the argument.
152#define QUOTE(x) #x
153#define STRINGIFY(x) QUOTE(x)
154
155#ifndef NDEBUG
156#define ALWAYS_INLINE
157#else
158#define ALWAYS_INLINE  __attribute__ ((always_inline))
159#endif
160
161#ifdef __clang__
162/* clang doesn't like attributes on lambda functions */
163#define ALWAYS_INLINE_LAMBDA
164#else
165#define ALWAYS_INLINE_LAMBDA ALWAYS_INLINE
166#endif
167
168#define NO_INLINE __attribute__ ((noinline))
169
170#if defined (__APPLE__)
171#define HOT_ATTR
172#define COLD_ATTR
173#else
174#define HOT_ATTR __attribute__ ((hot))
175#define COLD_ATTR __attribute__ ((cold))
176#endif
177
178#define PURE __attribute__ ((__pure__))
179#define WARN_UNUSED __attribute__((warn_unused_result))
180
181// A deprecated function to call to create a false use of the parameter, for example:
182//   int foo(int x) { UNUSED(x); return 10; }
183// to avoid compiler warnings. Going forward we prefer ATTRIBUTE_UNUSED.
184template<typename... T> void UNUSED(const T&...) {}
185
186// An attribute to place on a parameter to a function, for example:
187//   int foo(int x ATTRIBUTE_UNUSED) { return 10; }
188// to avoid compiler warnings.
189#define ATTRIBUTE_UNUSED __attribute__((__unused__))
190
191// Define that a position within code is unreachable, for example:
192//   int foo () { LOG(FATAL) << "Don't call me"; UNREACHABLE(); }
193// without the UNREACHABLE a return statement would be necessary.
194#define UNREACHABLE  __builtin_unreachable
195
196// Add the C++11 noreturn attribute.
197#define NO_RETURN [[ noreturn ]]  // NOLINT[whitespace/braces] [5]
198
199// The FALLTHROUGH_INTENDED macro can be used to annotate implicit fall-through
200// between switch labels:
201//  switch (x) {
202//    case 40:
203//    case 41:
204//      if (truth_is_out_there) {
205//        ++x;
206//        FALLTHROUGH_INTENDED;  // Use instead of/along with annotations in
207//                               // comments.
208//      } else {
209//        return x;
210//      }
211//    case 42:
212//      ...
213//
214//  As shown in the example above, the FALLTHROUGH_INTENDED macro should be
215//  followed by a semicolon. It is designed to mimic control-flow statements
216//  like 'break;', so it can be placed in most places where 'break;' can, but
217//  only if there are no statements on the execution path between it and the
218//  next switch label.
219//
220//  When compiled with clang in C++11 mode, the FALLTHROUGH_INTENDED macro is
221//  expanded to [[clang::fallthrough]] attribute, which is analysed when
222//  performing switch labels fall-through diagnostic ('-Wimplicit-fallthrough').
223//  See clang documentation on language extensions for details:
224//  http://clang.llvm.org/docs/LanguageExtensions.html#clang__fallthrough
225//
226//  When used with unsupported compilers, the FALLTHROUGH_INTENDED macro has no
227//  effect on diagnostics.
228//
229//  In either case this macro has no effect on runtime behavior and performance
230//  of code.
231#if defined(__clang__) && __cplusplus >= 201103L && defined(__has_warning)
232#if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
233#define FALLTHROUGH_INTENDED [[clang::fallthrough]]  // NOLINT
234#endif
235#endif
236
237#ifndef FALLTHROUGH_INTENDED
238#define FALLTHROUGH_INTENDED do { } while (0)
239#endif
240
241// Annotalysis thread-safety analysis support.
242#if defined(__SUPPORT_TS_ANNOTATION__) || defined(__clang__)
243#define THREAD_ANNOTATION_ATTRIBUTE__(x)   __attribute__((x))
244#else
245#define THREAD_ANNOTATION_ATTRIBUTE__(x)   // no-op
246#endif
247
248#define ACQUIRED_AFTER(...) THREAD_ANNOTATION_ATTRIBUTE__(acquired_after(__VA_ARGS__))
249#define ACQUIRED_BEFORE(...) THREAD_ANNOTATION_ATTRIBUTE__(acquired_before(__VA_ARGS__))
250#define GUARDED_BY(x) THREAD_ANNOTATION_ATTRIBUTE__(guarded_by(x))
251#define GUARDED_VAR THREAD_ANNOTATION_ATTRIBUTE__(guarded)
252#define LOCK_RETURNED(x) THREAD_ANNOTATION_ATTRIBUTE__(lock_returned(x))
253#define NO_THREAD_SAFETY_ANALYSIS THREAD_ANNOTATION_ATTRIBUTE__(no_thread_safety_analysis)
254#define PT_GUARDED_BY(x)
255// THREAD_ANNOTATION_ATTRIBUTE__(point_to_guarded_by(x))
256#define PT_GUARDED_VAR THREAD_ANNOTATION_ATTRIBUTE__(point_to_guarded)
257#define SCOPED_LOCKABLE THREAD_ANNOTATION_ATTRIBUTE__(scoped_lockable)
258
259#if defined(__clang__)
260#define EXCLUSIVE_LOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(exclusive_lock_function(__VA_ARGS__))
261#define EXCLUSIVE_TRYLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(exclusive_trylock_function(__VA_ARGS__))
262#define SHARED_LOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_lock_function(__VA_ARGS__))
263#define SHARED_TRYLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_trylock_function(__VA_ARGS__))
264#define UNLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(unlock_function(__VA_ARGS__))
265#define REQUIRES(...) THREAD_ANNOTATION_ATTRIBUTE__(requires_capability(__VA_ARGS__))
266#define SHARED_REQUIRES(...) THREAD_ANNOTATION_ATTRIBUTE__(requires_shared_capability(__VA_ARGS__))
267#define CAPABILITY(...) THREAD_ANNOTATION_ATTRIBUTE__(capability(__VA_ARGS__))
268#define SHARED_CAPABILITY(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_capability(__VA_ARGS__))
269#define ASSERT_CAPABILITY(...) THREAD_ANNOTATION_ATTRIBUTE__(assert_capability(__VA_ARGS__))
270#define ASSERT_SHARED_CAPABILITY(...) THREAD_ANNOTATION_ATTRIBUTE__(assert_shared_capability(__VA_ARGS__))
271#define RETURN_CAPABILITY(...) THREAD_ANNOTATION_ATTRIBUTE__(lock_returned(__VA_ARGS__))
272#define TRY_ACQUIRE(...) THREAD_ANNOTATION_ATTRIBUTE__(try_acquire_capability(__VA_ARGS__))
273#define TRY_ACQUIRE_SHARED(...) THREAD_ANNOTATION_ATTRIBUTE__(try_acquire_shared_capability(__VA_ARGS__))
274#define ACQUIRE(...) THREAD_ANNOTATION_ATTRIBUTE__(acquire_capability(__VA_ARGS__))
275#define ACQUIRE_SHARED(...) THREAD_ANNOTATION_ATTRIBUTE__(acquire_shared_capability(__VA_ARGS__))
276#define RELEASE(...) THREAD_ANNOTATION_ATTRIBUTE__(release_capability(__VA_ARGS__))
277#define RELEASE_SHARED(...) THREAD_ANNOTATION_ATTRIBUTE__(release_shared_capability(__VA_ARGS__))
278#define SCOPED_CAPABILITY THREAD_ANNOTATION_ATTRIBUTE__(scoped_lockable)
279#else
280#define EXCLUSIVE_LOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(exclusive_lock(__VA_ARGS__))
281#define EXCLUSIVE_TRYLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(exclusive_trylock(__VA_ARGS__))
282#define SHARED_LOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_lock(__VA_ARGS__))
283#define SHARED_TRYLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(shared_trylock(__VA_ARGS__))
284#define UNLOCK_FUNCTION(...) THREAD_ANNOTATION_ATTRIBUTE__(unlock(__VA_ARGS__))
285#define REQUIRES(...)
286#define SHARED_REQUIRES(...)
287#define CAPABILITY(...)
288#define SHARED_CAPABILITY(...)
289#define ASSERT_CAPABILITY(...)
290#define ASSERT_SHARED_CAPABILITY(...)
291#define RETURN_CAPABILITY(...)
292#define TRY_ACQUIRE(...)
293#define TRY_ACQUIRE_SHARED(...)
294#define ACQUIRE(...)
295#define ACQUIRE_SHARED(...)
296#define RELEASE(...)
297#define RELEASE_SHARED(...)
298#define SCOPED_CAPABILITY
299#endif
300
301#define LOCKABLE CAPABILITY("mutex")
302#define SHARED_LOCKABLE SHARED_CAPABILITY("mutex")
303
304#endif  // ART_RUNTIME_BASE_MACROS_H_
305