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 #pragma once
18
19 #include <stdint.h>
20
21 #define BIONIC_DISALLOW_COPY_AND_ASSIGN(TypeName) \
22 TypeName(const TypeName&) = delete; \
23 void operator=(const TypeName&) = delete
24
25 #define BIONIC_DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \
26 TypeName() = delete; \
27 BIONIC_DISALLOW_COPY_AND_ASSIGN(TypeName)
28
29 #define BIONIC_ROUND_UP_POWER_OF_2(value) \
30 ((sizeof(value) == 8) \
31 ? (1UL << (64 - __builtin_clzl(static_cast<unsigned long>(value)))) \
32 : (1UL << (32 - __builtin_clz(static_cast<unsigned int>(value)))))
33
align_down(uintptr_t p,size_t align)34 static constexpr uintptr_t align_down(uintptr_t p, size_t align) {
35 return p & ~(align - 1);
36 }
37
align_up(uintptr_t p,size_t align)38 static constexpr uintptr_t align_up(uintptr_t p, size_t align) {
39 return (p + align - 1) & ~(align - 1);
40 }
41
42 template <typename T>
align_down(T * p,size_t align)43 static inline T* align_down(T* p, size_t align) {
44 return reinterpret_cast<T*>(align_down(reinterpret_cast<uintptr_t>(p), align));
45 }
46
47 template <typename T>
align_up(T * p,size_t align)48 static inline T* align_up(T* p, size_t align) {
49 return reinterpret_cast<T*>(align_up(reinterpret_cast<uintptr_t>(p), align));
50 }
51
52 #if defined(__arm__)
53 // Do not emit anything for arm, clang does not allow emiting an arm unwind
54 // directive.
55 // #define BIONIC_STOP_UNWIND asm volatile(".cantunwind")
56 #define BIONIC_STOP_UNWIND
57 #elif defined(__aarch64__)
58 #define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined x30")
59 #elif defined(__i386__)
60 #define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined \%eip")
61 #elif defined(__x86_64__)
62 #define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined \%rip")
63 #elif defined (__mips__)
64 #define BIONIC_STOP_UNWIND asm volatile(".cfi_undefined $ra")
65 #endif
66
67 // The arraysize(arr) macro returns the # of elements in an array arr.
68 // The expression is a compile-time constant, and therefore can be
69 // used in defining new arrays, for example. If you use arraysize on
70 // a pointer by mistake, you will get a compile-time error.
71 //
72 // One caveat is that arraysize() doesn't accept any array of an
73 // anonymous type or a type defined inside a function.
74 //
75 // This template function declaration is used in defining arraysize.
76 // Note that the function doesn't need an implementation, as we only
77 // use its type.
78 template <typename T, size_t N>
79 char (&ArraySizeHelper(T (&array)[N]))[N]; // NOLINT(readability/casting)
80
81 #define arraysize(array) (sizeof(ArraySizeHelper(array)))
82
83 // Used to inform clang's -Wimplicit-fallthrough that a fallthrough is intended. There's no way to
84 // silence (or enable, apparently) -Wimplicit-fallthrough in C yet.
85 #ifdef __cplusplus
86 #define __BIONIC_FALLTHROUGH [[clang::fallthrough]]
87 #else
88 #define __BIONIC_FALLTHROUGH
89 #endif
90