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Commit | Line | Data |
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cc9d8a3b FF |
1 | /* compiler.h: macros to abstract away compiler specifics |
2 | * | |
3 | * This work is licensed under the terms of the GNU GPL, version 2 or later. | |
4 | * See the COPYING file in the top-level directory. | |
5 | */ | |
5c026320 LC |
6 | |
7 | #ifndef COMPILER_H | |
8 | #define COMPILER_H | |
9 | ||
51965597 MAL |
10 | #define HOST_BIG_ENDIAN (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) |
11 | ||
12 | /* HOST_LONG_BITS is the size of a native pointer in bits. */ | |
13 | #define HOST_LONG_BITS (__SIZEOF_POINTER__ * 8) | |
14 | ||
8bff06a0 PB |
15 | #if defined __clang_analyzer__ || defined __COVERITY__ |
16 | #define QEMU_STATIC_ANALYSIS 1 | |
17 | #endif | |
5c026320 | 18 | |
875df03b PB |
19 | #ifdef __cplusplus |
20 | #define QEMU_EXTERN_C extern "C" | |
21 | #else | |
22 | #define QEMU_EXTERN_C extern | |
23 | #endif | |
24 | ||
48bb55bf | 25 | #if defined(_WIN32) && (defined(__x86_64__) || defined(__i386__)) |
0f7fdd34 SW |
26 | # define QEMU_PACKED __attribute__((gcc_struct, packed)) |
27 | #else | |
28 | # define QEMU_PACKED __attribute__((packed)) | |
29 | #endif | |
30 | ||
911a4d22 EC |
31 | #define QEMU_ALIGNED(X) __attribute__((aligned(X))) |
32 | ||
49120868 PM |
33 | #ifndef glue |
34 | #define xglue(x, y) x ## y | |
35 | #define glue(x, y) xglue(x, y) | |
48805df9 YF |
36 | #define stringify(s) tostring(s) |
37 | #define tostring(s) #s | |
49120868 PM |
38 | #endif |
39 | ||
bb718463 MA |
40 | /* Expands into an identifier stemN, where N is another number each time */ |
41 | #define MAKE_IDENTFIER(stem) glue(stem, __COUNTER__) | |
42 | ||
49120868 | 43 | #ifndef likely |
49120868 PM |
44 | #define likely(x) __builtin_expect(!!(x), 1) |
45 | #define unlikely(x) __builtin_expect(!!(x), 0) | |
46 | #endif | |
47 | ||
48 | #ifndef container_of | |
49 | #define container_of(ptr, type, member) ({ \ | |
50 | const typeof(((type *) 0)->member) *__mptr = (ptr); \ | |
51 | (type *) ((char *) __mptr - offsetof(type, member));}) | |
52 | #endif | |
53 | ||
f18793b0 SH |
54 | #define sizeof_field(type, field) sizeof(((type *)0)->field) |
55 | ||
5d5b33c0 HR |
56 | /* |
57 | * Calculate the number of bytes up to and including the given 'field' of | |
58 | * 'container'. | |
59 | */ | |
60 | #define endof(container, field) \ | |
61 | (offsetof(container, field) + sizeof_field(container, field)) | |
62 | ||
49120868 | 63 | /* Convert from a base type to a parent type, with compile time checking. */ |
49120868 PM |
64 | #define DO_UPCAST(type, field, dev) ( __extension__ ( { \ |
65 | char __attribute__((unused)) offset_must_be_zero[ \ | |
66 | -offsetof(type, field)]; \ | |
67 | container_of(dev, type, field);})) | |
49120868 PM |
68 | |
69 | #define typeof_field(type, field) typeof(((type *)0)->field) | |
70 | #define type_check(t1,t2) ((t1*)0 - (t2*)0) | |
71 | ||
f291887e MT |
72 | #define QEMU_BUILD_BUG_ON_STRUCT(x) \ |
73 | struct { \ | |
74 | int:(x) ? -1 : 1; \ | |
75 | } | |
76 | ||
9139b567 | 77 | #define QEMU_BUILD_BUG_MSG(x, msg) _Static_assert(!(x), msg) |
5c026320 | 78 | |
9139b567 HR |
79 | #define QEMU_BUILD_BUG_ON(x) QEMU_BUILD_BUG_MSG(x, "not expecting: " #x) |
80 | ||
d757573e MT |
81 | #define QEMU_BUILD_BUG_ON_ZERO(x) (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \ |
82 | sizeof(QEMU_BUILD_BUG_ON_STRUCT(x))) | |
83 | ||
9edc6313 | 84 | #if !defined(__clang__) && defined(_WIN32) |
28f86163 MAL |
85 | /* |
86 | * Map __printf__ to __gnu_printf__ because we want standard format strings even | |
87 | * when MinGW or GLib include files use __printf__. | |
88 | */ | |
9edc6313 | 89 | # define __printf__ __gnu_printf__ |
5c026320 LC |
90 | #endif |
91 | ||
798b8581 TH |
92 | #ifndef __has_warning |
93 | #define __has_warning(x) 0 /* compatibility with non-clang compilers */ | |
94 | #endif | |
95 | ||
d83414e1 MAL |
96 | #ifndef __has_feature |
97 | #define __has_feature(x) 0 /* compatibility with non-clang compilers */ | |
98 | #endif | |
5a358b39 PM |
99 | |
100 | #ifndef __has_builtin | |
101 | #define __has_builtin(x) 0 /* compatibility with non-clang compilers */ | |
102 | #endif | |
103 | ||
f773b423 | 104 | #if __has_builtin(__builtin_assume_aligned) || !defined(__clang__) |
5a358b39 PM |
105 | #define HAS_ASSUME_ALIGNED |
106 | #endif | |
97ff87c0 TH |
107 | |
108 | #ifndef __has_attribute | |
109 | #define __has_attribute(x) 0 /* compatibility with older GCC */ | |
110 | #endif | |
111 | ||
c213ef9a MAL |
112 | #if defined(__SANITIZE_ADDRESS__) || __has_feature(address_sanitizer) |
113 | # define QEMU_SANITIZE_ADDRESS 1 | |
114 | #endif | |
115 | ||
116 | #if defined(__SANITIZE_THREAD__) || __has_feature(thread_sanitizer) | |
117 | # define QEMU_SANITIZE_THREAD 1 | |
118 | #endif | |
119 | ||
97ff87c0 TH |
120 | /* |
121 | * GCC doesn't provide __has_attribute() until GCC 5, but we know all the GCC | |
122 | * versions we support have the "flatten" attribute. Clang may not have the | |
123 | * "flatten" attribute but always has __has_attribute() to check for it. | |
124 | */ | |
125 | #if __has_attribute(flatten) || !defined(__clang__) | |
126 | # define QEMU_FLATTEN __attribute__((flatten)) | |
127 | #else | |
128 | # define QEMU_FLATTEN | |
129 | #endif | |
e6cd4bb5 RH |
130 | |
131 | /* | |
132 | * If __attribute__((error)) is present, use it to produce an error at | |
133 | * compile time. Otherwise, one must wait for the linker to diagnose | |
134 | * the missing symbol. | |
135 | */ | |
136 | #if __has_attribute(error) | |
137 | # define QEMU_ERROR(X) __attribute__((error(X))) | |
138 | #else | |
139 | # define QEMU_ERROR(X) | |
140 | #endif | |
1daff2f8 PMD |
141 | |
142 | /* | |
143 | * The nonstring variable attribute specifies that an object or member | |
144 | * declaration with type array of char or pointer to char is intended | |
145 | * to store character arrays that do not necessarily contain a terminating | |
146 | * NUL character. This is useful in detecting uses of such arrays or pointers | |
147 | * with functions that expect NUL-terminated strings, and to avoid warnings | |
148 | * when such an array or pointer is used as an argument to a bounded string | |
149 | * manipulation function such as strncpy. | |
150 | */ | |
151 | #if __has_attribute(nonstring) | |
152 | # define QEMU_NONSTRING __attribute__((nonstring)) | |
153 | #else | |
154 | # define QEMU_NONSTRING | |
155 | #endif | |
c6b716cd RH |
156 | |
157 | /* | |
158 | * Forced inlining may be desired to encourage constant propagation | |
159 | * of function parameters. However, it can also make debugging harder, | |
160 | * so disable it for a non-optimizing build. | |
161 | */ | |
162 | #if defined(__OPTIMIZE__) | |
163 | #define QEMU_ALWAYS_INLINE __attribute__((always_inline)) | |
164 | #else | |
165 | #define QEMU_ALWAYS_INLINE | |
166 | #endif | |
5a358b39 | 167 | |
d84568b7 TH |
168 | /** |
169 | * In most cases, normal "fallthrough" comments are good enough for | |
170 | * switch-case statements, but sometimes the compiler has problems | |
171 | * with those. In that case you can use QEMU_FALLTHROUGH instead. | |
172 | */ | |
173 | #if __has_attribute(fallthrough) | |
174 | # define QEMU_FALLTHROUGH __attribute__((fallthrough)) | |
175 | #else | |
176 | # define QEMU_FALLTHROUGH do {} while (0) /* fallthrough */ | |
177 | #endif | |
178 | ||
c905a368 DB |
179 | #ifdef CONFIG_CFI |
180 | /* | |
181 | * If CFI is enabled, use an attribute to disable cfi-icall on the following | |
182 | * function | |
183 | */ | |
184 | #define QEMU_DISABLE_CFI __attribute__((no_sanitize("cfi-icall"))) | |
185 | #else | |
186 | /* If CFI is not enabled, use an empty define to not change the behavior */ | |
187 | #define QEMU_DISABLE_CFI | |
188 | #endif | |
189 | ||
b0438861 PM |
190 | /* |
191 | * Apple clang version 14 has a bug in its __builtin_subcll(); define | |
192 | * BUILTIN_SUBCLL_BROKEN for the offending versions so we can avoid it. | |
193 | * When a version of Apple clang which has this bug fixed is released | |
194 | * we can add an upper bound to this check. | |
195 | * See https://gitlab.com/qemu-project/qemu/-/issues/1631 | |
196 | * and https://gitlab.com/qemu-project/qemu/-/issues/1659 for details. | |
197 | * The bug never made it into any upstream LLVM releases, only Apple ones. | |
198 | */ | |
199 | #if defined(__apple_build_version__) && __clang_major__ >= 14 | |
200 | #define BUILTIN_SUBCLL_BROKEN | |
201 | #endif | |
202 | ||
d79b9202 PB |
203 | #if __has_attribute(annotate) |
204 | #define QEMU_ANNOTATE(x) __attribute__((annotate(x))) | |
205 | #else | |
206 | #define QEMU_ANNOTATE(x) | |
207 | #endif | |
208 | ||
5c026320 | 209 | #endif /* COMPILER_H */ |