xref: /aosp_15_r20/system/chre/apps/nearby/third_party/contexthub/chre/util/include/chre/util/macros.h (revision 84e339476a462649f82315436d70fd732297a399)
1 /*
2  * Copyright (C) 2016 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 CHRE_UTIL_MACROS_H_
18 #define CHRE_UTIL_MACROS_H_
19 
20 #ifndef UNUSED_VAR
21 #define UNUSED_VAR(var) ((void)(var))
22 #endif
23 
24 /**
25  * Obtains the number of elements in a C-style array.
26  */
27 #ifndef ARRAY_SIZE
28 #define ARRAY_SIZE(array) (sizeof(array) / sizeof((array)[0]))
29 #endif
30 
31 #ifndef ARRAY_END
32 #define ARRAY_END(array) (array + ARRAY_SIZE(array))
33 #endif
34 
35 /** Determines if the provided bit is set in the provided value. */
36 #ifndef IS_BIT_SET
37 #define IS_BIT_SET(value, bit) (((value) & (bit)) == (bit))
38 #endif
39 
40 /**
41  * Performs macro expansion then converts the value into a string literal
42  */
43 #ifndef STRINGIFY
44 #define STRINGIFY(x) STRINGIFY2(x)
45 #define STRINGIFY2(x) #x
46 #endif
47 
48 /**
49  * Checks if a bitmask contains the specified value
50  */
51 #ifndef BITMASK_HAS_VALUE
52 #define BITMASK_HAS_VALUE(mask, value) ((mask & value) == value)
53 #endif
54 
55 /**
56  * Min/max macros.
57  */
58 #ifndef MIN
59 #define MIN(a, b) ((a) < (b) ? (a) : (b))
60 #endif
61 
62 #ifndef MAX
63 #define MAX(a, b) ((a) > (b) ? (a) : (b))
64 #endif
65 
66 /**
67  * Obtain the number of arguments passed into a macro up till 20 args
68  */
69 #define VA_NUM_ARGS(...)                                                       \
70   VA_NUM_ARGS_IMPL(__VA_ARGS__, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, \
71                    8, 7, 6, 5, 4, 3, 2, 1)
72 #define VA_NUM_ARGS_IMPL(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, \
73                          _13, _14_, _15, _16, _17, _18, _19, _20, N, ...)   \
74   N
75 
76 /**
77  * Concats two preprocessor tokens together.
78  * If passed in args are macros, they are resolved first, then concat'd
79  */
80 #define MACRO_CONCAT2(x, y) x##y
81 #define MACRO_CONCAT(x, y) MACRO_CONCAT2(x, y)
82 
83 /**
84  * Get a list of types of the passed in parameters to TYPE_LIST(...)
85  */
86 #define TYPE_LIST_1(a) decltype(a)
87 #define TYPE_LIST_2(a, ...) decltype(a), TYPE_LIST_1(__VA_ARGS__)
88 #define TYPE_LIST_3(a, ...) decltype(a), TYPE_LIST_2(__VA_ARGS__)
89 #define TYPE_LIST_4(a, ...) decltype(a), TYPE_LIST_3(__VA_ARGS__)
90 #define TYPE_LIST_5(a, ...) decltype(a), TYPE_LIST_4(__VA_ARGS__)
91 #define TYPE_LIST_6(a, ...) decltype(a), TYPE_LIST_5(__VA_ARGS__)
92 #define TYPE_LIST_7(a, ...) decltype(a), TYPE_LIST_6(__VA_ARGS__)
93 #define TYPE_LIST_8(a, ...) decltype(a), TYPE_LIST_7(__VA_ARGS__)
94 #define TYPE_LIST_9(a, ...) decltype(a), TYPE_LIST_8(__VA_ARGS__)
95 #define TYPE_LIST_10(a, ...) decltype(a), TYPE_LIST_9(__VA_ARGS__)
96 #define TYPE_LIST_11(a, ...) decltype(a), TYPE_LIST_10(__VA_ARGS__)
97 #define TYPE_LIST_12(a, ...) decltype(a), TYPE_LIST_11(__VA_ARGS__)
98 #define TYPE_LIST_13(a, ...) decltype(a), TYPE_LIST_12(__VA_ARGS__)
99 #define TYPE_LIST_14(a, ...) decltype(a), TYPE_LIST_13(__VA_ARGS__)
100 #define TYPE_LIST_15(a, ...) decltype(a), TYPE_LIST_14(__VA_ARGS__)
101 #define TYPE_LIST_16(a, ...) decltype(a), TYPE_LIST_15(__VA_ARGS__)
102 #define TYPE_LIST_17(a, ...) decltype(a), TYPE_LIST_16(__VA_ARGS__)
103 #define TYPE_LIST_18(a, ...) decltype(a), TYPE_LIST_17(__VA_ARGS__)
104 #define TYPE_LIST_19(a, ...) decltype(a), TYPE_LIST_18(__VA_ARGS__)
105 #define TYPE_LIST_20(a, ...) decltype(a), TYPE_LIST_19(__VA_ARGS__)
106 
107 #define TYPE_LIST(...) \
108   MACRO_CONCAT(TYPE_LIST_, VA_NUM_ARGS(__VA_ARGS__))(__VA_ARGS__)
109 
110 // Compiler-specific functionality
111 #if defined(__clang__) || defined(__GNUC__)
112 
113 //! Exports a symbol so it is accessible outside the .so (symbols are hidden by
114 //! default)
115 #define DLL_EXPORT __attribute__((visibility("default")))
116 
117 //! Marks a symbol as weak, so that it may be overridden at link time
118 #define WEAK_SYMBOL __attribute__((weak))
119 
120 #else
121 
122 #warning "Missing compiler-specific macros"
123 
124 #endif
125 
126 #endif  // CHRE_UTIL_MACROS_H_
127