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 _BIONIC_MACROS_H_
18 #define _BIONIC_MACROS_H_
19
20 #include <stdint.h>
21
22 // Frameworks OpenGL code currently leaks this header and allows
23 // collisions with other declarations, e.g., from libnativehelper.
24 // TODO: Remove once cleaned up. b/18334516
25 #if !defined(DISALLOW_COPY_AND_ASSIGN)
26 // DISALLOW_COPY_AND_ASSIGN disallows the copy and operator= functions.
27 // It goes in the private: declarations in a class.
28 #define DISALLOW_COPY_AND_ASSIGN(TypeName) \
29 TypeName(const TypeName&) = delete; \
30 void operator=(const TypeName&) = delete
31 #endif // !defined(DISALLOW_COPY_AND_ASSIGN)
32
33 // A macro to disallow all the implicit constructors, namely the
34 // default constructor, copy constructor and operator= functions.
35 //
36 // This should be used in the private: declarations for a class
37 // that wants to prevent anyone from instantiating it. This is
38 // especially useful for classes containing only static methods.
39 #define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
40 TypeName() = delete; \
41 DISALLOW_COPY_AND_ASSIGN(TypeName)
42
43 #define BIONIC_ROUND_UP_POWER_OF_2(value) \
44 ((sizeof(value) == 8) \
45 ? (1UL << (64 - __builtin_clzl(static_cast<unsigned long>(value)))) \
46 : (1UL << (32 - __builtin_clz(static_cast<unsigned int>(value)))))
47
align_down(uintptr_t p,size_t align)48 static constexpr uintptr_t align_down(uintptr_t p, size_t align) {
49 return p & ~(align - 1);
50 }
51
align_up(uintptr_t p,size_t align)52 static constexpr uintptr_t align_up(uintptr_t p, size_t align) {
53 return (p + align - 1) & ~(align - 1);
54 }
55
56 template <typename T>
align_down(T * p,size_t align)57 static inline T* align_down(T* p, size_t align) {
58 return reinterpret_cast<T*>(align_down(reinterpret_cast<uintptr_t>(p), align));
59 }
60
61 template <typename T>
align_up(T * p,size_t align)62 static inline T* align_up(T* p, size_t align) {
63 return reinterpret_cast<T*>(align_up(reinterpret_cast<uintptr_t>(p), align));
64 }
65
66 #if defined(__arm__)
67 // Do not emit anything for arm, clang does not allow emiting an arm unwind
68 // directive.
69 // #define BIONIC_STOP_UNWIND asm volatile(".cantunwind")
70 #define BIONIC_STOP_UNWIND
71 #elif defined(__aarch64__)
72 #define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined x30")
73 #elif defined(__i386__)
74 #define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined \%eip")
75 #elif defined(__x86_64__)
76 #define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined \%rip")
77 #elif defined (__mips__)
78 #define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined $ra")
79 #endif
80
81 // The arraysize(arr) macro returns the # of elements in an array arr.
82 // The expression is a compile-time constant, and therefore can be
83 // used in defining new arrays, for example. If you use arraysize on
84 // a pointer by mistake, you will get a compile-time error.
85 //
86 // One caveat is that arraysize() doesn't accept any array of an
87 // anonymous type or a type defined inside a function.
88 //
89 // This template function declaration is used in defining arraysize.
90 // Note that the function doesn't need an implementation, as we only
91 // use its type.
92 template <typename T, size_t N>
93 char (&ArraySizeHelper(T (&array)[N]))[N]; // NOLINT(readability/casting)
94
95 #define arraysize(array) (sizeof(ArraySizeHelper(array)))
96
97 #endif // _BIONIC_MACROS_H_
98