1 /* $NetBSD: cdefs.h,v 1.58 2004/12/11 05:59:00 christos Exp $ */
2
3 /*
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Berkeley Software Design, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)cdefs.h 8.8 (Berkeley) 1/9/95
35 */
36
37 #pragma once
38
39 /**
40 * `__BIONIC__` is always defined if you're building with bionic. See
41 * https://android.googlesource.com/platform/bionic/+/master/docs/defines.md.
42 */
43 #define __BIONIC__ 1
44
45 #if defined(__cplusplus)
46 #define __BEGIN_DECLS extern "C" {
47 #define __END_DECLS }
48 #else
49 #define __BEGIN_DECLS
50 #define __END_DECLS
51 #endif
52
53 #define __strong_alias(alias, sym) \
54 __asm__(".global " #alias "\n" \
55 #alias " = " #sym);
56
57 #if defined(__cplusplus)
58 #define __BIONIC_CAST(_k,_t,_v) (_k<_t>(_v))
59 #else
60 #define __BIONIC_CAST(_k,_t,_v) ((_t) (_v))
61 #endif
62
63 #define __BIONIC_ALIGN(__value, __alignment) (((__value) + (__alignment)-1) & ~((__alignment)-1))
64
65 /*
66 * The __CONCAT macro is used to concatenate parts of symbol names, e.g.
67 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo.
68 * The __CONCAT macro is a bit tricky -- make sure you don't put spaces
69 * in between its arguments. __CONCAT can also concatenate double-quoted
70 * strings produced by the __STRING macro, but this only works with ANSI C.
71 */
72
73 #define __P(protos) protos /* full-blown ANSI C */
74
75 #define __CONCAT1(x,y) x ## y
76 #define __CONCAT(x,y) __CONCAT1(x,y)
77 #define ___CONCAT(x,y) __CONCAT(x,y)
78
79 #define __STRING(x) #x
80 #define ___STRING(x) __STRING(x)
81
82 #if defined(__cplusplus)
83 #define __inline inline /* convert to C++ keyword */
84 #endif /* !__cplusplus */
85
86 #define __always_inline __attribute__((__always_inline__))
87 #define __attribute_const__ __attribute__((__const__))
88 #define __attribute_pure__ __attribute__((__pure__))
89 #define __dead __attribute__((__noreturn__))
90 #define __noreturn __attribute__((__noreturn__))
91 #define __mallocfunc __attribute__((__malloc__))
92 #define __packed __attribute__((__packed__))
93 #define __returns_twice __attribute__((__returns_twice__))
94 #define __unused __attribute__((__unused__))
95 #define __used __attribute__((__used__))
96
97 #define __printflike(x, y) __attribute__((__format__(printf, x, y)))
98 #define __scanflike(x, y) __attribute__((__format__(scanf, x, y)))
99 #define __strftimelike(x) __attribute__((__format__(strftime, x, 0)))
100
101 /*
102 * GNU C version 2.96 added explicit branch prediction so that
103 * the CPU back-end can hint the processor and also so that
104 * code blocks can be reordered such that the predicted path
105 * sees a more linear flow, thus improving cache behavior, etc.
106 *
107 * The following two macros provide us with a way to use this
108 * compiler feature. Use __predict_true() if you expect the expression
109 * to evaluate to true, and __predict_false() if you expect the
110 * expression to evaluate to false.
111 *
112 * A few notes about usage:
113 *
114 * * Generally, __predict_false() error condition checks (unless
115 * you have some _strong_ reason to do otherwise, in which case
116 * document it), and/or __predict_true() `no-error' condition
117 * checks, assuming you want to optimize for the no-error case.
118 *
119 * * Other than that, if you don't know the likelihood of a test
120 * succeeding from empirical or other `hard' evidence, don't
121 * make predictions.
122 *
123 * * These are meant to be used in places that are run `a lot'.
124 * It is wasteful to make predictions in code that is run
125 * seldomly (e.g. at subsystem initialization time) as the
126 * basic block reordering that this affects can often generate
127 * larger code.
128 */
129 #define __predict_true(exp) __builtin_expect((exp) != 0, 1)
130 #define __predict_false(exp) __builtin_expect((exp) != 0, 0)
131
132 #define __wur __attribute__((__warn_unused_result__))
133
134 #define __errorattr(msg) __attribute__((unavailable(msg)))
135 #define __warnattr(msg) __attribute__((deprecated(msg)))
136 #define __warnattr_real(msg) __attribute__((deprecated(msg)))
137 #define __enable_if(cond, msg) __attribute__((enable_if(cond, msg)))
138 #define __clang_error_if(cond, msg) __attribute__((diagnose_if(cond, msg, "error")))
139 #define __clang_warning_if(cond, msg) __attribute__((diagnose_if(cond, msg, "warning")))
140
141 #if defined(ANDROID_STRICT)
142 /*
143 * For things that are sketchy, but not necessarily an error. FIXME: Enable
144 * this.
145 */
146 # define __warnattr_strict(msg) /* __warnattr(msg) */
147 #else
148 # define __warnattr_strict(msg)
149 #endif
150
151 /*
152 * Some BSD source needs these macros.
153 * Originally they embedded the rcs versions of each source file
154 * in the generated binary. We strip strings during build anyway,.
155 */
156 #define __IDSTRING(_prefix,_s) /* nothing */
157 #define __COPYRIGHT(_s) /* nothing */
158 #define __FBSDID(_s) /* nothing */
159 #define __RCSID(_s) /* nothing */
160 #define __SCCSID(_s) /* nothing */
161
162 /*
163 * With bionic, you always get all C and POSIX API.
164 *
165 * If you want BSD and/or GNU extensions, _BSD_SOURCE and/or _GNU_SOURCE are
166 * expected to be defined by callers before *any* standard header file is
167 * included.
168 *
169 * In our header files we test against __USE_BSD and __USE_GNU.
170 */
171 #if defined(_GNU_SOURCE)
172 # define __USE_BSD 1
173 # define __USE_GNU 1
174 #endif
175
176 #if defined(_BSD_SOURCE)
177 # define __USE_BSD 1
178 #endif
179
180 /*
181 * _FILE_OFFSET_BITS 64 support.
182 * See https://android.googlesource.com/platform/bionic/+/master/docs/32-bit-abi.md
183 */
184 #if !defined(__LP64__) && defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS == 64
185 # define __USE_FILE_OFFSET64 1
186 /*
187 * Note that __RENAME_IF_FILE_OFFSET64 is only valid if the off_t and off64_t
188 * functions were both added at the same API level because if you use this,
189 * you only have one declaration to attach __INTRODUCED_IN to.
190 */
191 # define __RENAME_IF_FILE_OFFSET64(func) __RENAME(func)
192 #else
193 # define __RENAME_IF_FILE_OFFSET64(func)
194 #endif
195
196 /*
197 * For LP32, `long double` == `double`. Historically many `long double` functions were incorrect
198 * on x86, missing on most architectures, and even if they are present and correct, linking to
199 * them just bloats your ELF file by adding extra relocations. The __BIONIC_LP32_USE_LONG_DOUBLE
200 * macro lets us test the headers both ways (and adds an escape valve).
201 *
202 * Note that some functions have their __RENAME_LDBL commented out as a sign that although we could
203 * use __RENAME_LDBL it would actually cause the function to be introduced later because the
204 * `long double` variant appeared before the `double` variant.
205 *
206 * The _NO_GUARD_FOR_NDK variants keep the __VERSIONER_NO_GUARD behavior working for the NDK. This
207 * allows libc++ to refer to these functions in inlines without needing to guard them, needed since
208 * libc++ doesn't currently guard these calls. There's no risk to the apps though because using
209 * those APIs will still cause a link error.
210 */
211 #if defined(__LP64__) || defined(__BIONIC_LP32_USE_LONG_DOUBLE)
212 #define __RENAME_LDBL(rewrite,rewrite_api_level,regular_api_level) __INTRODUCED_IN(regular_api_level)
213 #define __RENAME_LDBL_NO_GUARD_FOR_NDK(rewrite,rewrite_api_level,regular_api_level) __INTRODUCED_IN_NO_GUARD_FOR_NDK(regular_api_level)
214 #else
215 #define __RENAME_LDBL(rewrite,rewrite_api_level,regular_api_level) __RENAME(rewrite) __INTRODUCED_IN(rewrite_api_level)
216 #define __RENAME_LDBL_NO_GUARD_FOR_NDK(rewrite,rewrite_api_level,regular_api_level) __RENAME(rewrite) __INTRODUCED_IN_NO_GUARD_FOR_NDK(rewrite_api_level)
217 #endif
218
219 /*
220 * On all architectures, `struct stat` == `struct stat64`, but LP32 didn't gain the *64 functions
221 * until API level 21.
222 */
223 #if defined(__LP64__) || defined(__BIONIC_LP32_USE_STAT64)
224 #define __RENAME_STAT64(rewrite,rewrite_api_level,regular_api_level) __INTRODUCED_IN(regular_api_level)
225 #else
226 #define __RENAME_STAT64(rewrite,rewrite_api_level,regular_api_level) __RENAME(rewrite) __INTRODUCED_IN(rewrite_api_level)
227 #endif
228
229 /* glibc compatibility. */
230 #if defined(__LP64__)
231 #define __WORDSIZE 64
232 #else
233 #define __WORDSIZE 32
234 #endif
235
236 /*
237 * When _FORTIFY_SOURCE is defined, automatic bounds checking is
238 * added to commonly used libc functions. If a buffer overrun is
239 * detected, the program is safely aborted.
240 *
241 * https://android-developers.googleblog.com/2017/04/fortify-in-android.html
242 */
243
244 #define __BIONIC_FORTIFY_UNKNOWN_SIZE ((size_t) -1)
245
246 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0
247 /* FORTIFY can interfere with pattern-matching of clang-tidy/the static analyzer. */
248 # if !defined(__clang_analyzer__)
249 # define __BIONIC_FORTIFY 1
250 /* ASAN has interceptors that FORTIFY's _chk functions can break. */
251 # if __has_feature(address_sanitizer)
252 # define __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED 0
253 # else
254 # define __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED 1
255 # endif
256 # endif
257 #endif
258
259 // As we move some FORTIFY checks to be always on, __bos needs to be
260 // always available.
261 #if defined(__BIONIC_FORTIFY)
262 # if _FORTIFY_SOURCE == 2
263 # define __bos_level 1
264 # else
265 # define __bos_level 0
266 # endif
267 #else
268 # define __bos_level 0
269 #endif
270
271 #define __bosn(s, n) __builtin_object_size((s), (n))
272 #define __bos(s) __bosn((s), __bos_level)
273
274 #if defined(__BIONIC_FORTIFY)
275 # define __bos0(s) __bosn((s), 0)
276 # define __pass_object_size_n(n) __attribute__((pass_object_size(n)))
277 /*
278 * FORTIFY'ed functions all have either enable_if or pass_object_size, which
279 * makes taking their address impossible. Saying (&read)(foo, bar, baz); will
280 * therefore call the unFORTIFYed version of read.
281 */
282 # define __call_bypassing_fortify(fn) (&fn)
283 /*
284 * Because clang-FORTIFY uses overloads, we can't mark functions as `extern inline` without making
285 * them available externally. FORTIFY'ed functions try to be as close to possible as 'invisible';
286 * having stack protectors detracts from that (b/182948263).
287 */
288 # define __BIONIC_FORTIFY_INLINE static __inline__ __attribute__((no_stack_protector)) \
289 __always_inline __VERSIONER_FORTIFY_INLINE
290 /*
291 * We should use __BIONIC_FORTIFY_VARIADIC instead of __BIONIC_FORTIFY_INLINE
292 * for variadic functions because compilers cannot inline them.
293 * The __always_inline attribute is useless, misleading, and could trigger
294 * clang compiler bug to incorrectly inline variadic functions.
295 */
296 # define __BIONIC_FORTIFY_VARIADIC static __inline__
297 /* Error functions don't have bodies, so they can just be static. */
298 # define __BIONIC_ERROR_FUNCTION_VISIBILITY static __attribute__((unused))
299 #else
300 /* Further increase sharing for some inline functions */
301 # define __pass_object_size_n(n)
302 #endif
303 #define __pass_object_size __pass_object_size_n(__bos_level)
304 #define __pass_object_size0 __pass_object_size_n(0)
305
306 /* Intended for use in unevaluated contexts, e.g. diagnose_if conditions. */
307 #define __bos_unevaluated_lt(bos_val, val) \
308 ((bos_val) != __BIONIC_FORTIFY_UNKNOWN_SIZE && (bos_val) < (val))
309
310 #define __bos_unevaluated_le(bos_val, val) \
311 ((bos_val) != __BIONIC_FORTIFY_UNKNOWN_SIZE && (bos_val) <= (val))
312
313 /* Intended for use in evaluated contexts. */
314 #define __bos_dynamic_check_impl_and(bos_val, op, index, cond) \
315 ((bos_val) == __BIONIC_FORTIFY_UNKNOWN_SIZE || \
316 (__builtin_constant_p(index) && bos_val op index && (cond)))
317
318 #define __bos_dynamic_check_impl(bos_val, op, index) \
319 __bos_dynamic_check_impl_and(bos_val, op, index, 1)
320
321 #define __bos_trivially_ge(bos_val, index) __bos_dynamic_check_impl((bos_val), >=, (index))
322 #define __bos_trivially_gt(bos_val, index) __bos_dynamic_check_impl((bos_val), >, (index))
323
324 #if defined(__BIONIC_FORTIFY) || defined(__BIONIC_DECLARE_FORTIFY_HELPERS)
325 # define __BIONIC_INCLUDE_FORTIFY_HEADERS 1
326 #endif
327
328 #define __overloadable __attribute__((overloadable))
329
330 /* Used to tag non-static symbols that are private and never exposed by the shared library. */
331 #define __LIBC_HIDDEN__ __attribute__((visibility("hidden")))
332
333 /*
334 * Used to tag symbols that should be hidden for 64-bit,
335 * but visible to preserve binary compatibility for LP32.
336 */
337 #ifdef __LP64__
338 #define __LIBC32_LEGACY_PUBLIC__ __attribute__((visibility("hidden")))
339 #else
340 #define __LIBC32_LEGACY_PUBLIC__ __attribute__((visibility("default")))
341 #endif
342
343 /* Used to rename functions so that the compiler emits a call to 'x' rather than the function this was applied to. */
344 #define __RENAME(x) __asm__(#x)
345
346 #if __has_builtin(__builtin_umul_overflow) || __GNUC__ >= 5
347 #if defined(__LP64__)
348 #define __size_mul_overflow(a, b, result) __builtin_umull_overflow(a, b, result)
349 #else
350 #define __size_mul_overflow(a, b, result) __builtin_umul_overflow(a, b, result)
351 #endif
352 #else
353 extern __inline__ __always_inline __attribute__((gnu_inline))
__size_mul_overflow(__SIZE_TYPE__ a,__SIZE_TYPE__ b,__SIZE_TYPE__ * result)354 int __size_mul_overflow(__SIZE_TYPE__ a, __SIZE_TYPE__ b, __SIZE_TYPE__ *result) {
355 *result = a * b;
356 static const __SIZE_TYPE__ mul_no_overflow = 1UL << (sizeof(__SIZE_TYPE__) * 4);
357 return (a >= mul_no_overflow || b >= mul_no_overflow) && a > 0 && (__SIZE_TYPE__)-1 / a < b;
358 }
359 #endif
360
361 /*
362 * Used when we need to check for overflow when multiplying x and y. This
363 * should only be used where __size_mul_overflow can not work, because it makes
364 * assumptions that __size_mul_overflow doesn't (x and y are positive, ...),
365 * *and* doesn't make use of compiler intrinsics, so it's probably slower than
366 * __size_mul_overflow.
367 */
368 #define __unsafe_check_mul_overflow(x, y) ((__SIZE_TYPE__)-1 / (x) < (y))
369
370 #include <android/versioning.h>
371 #include <android/api-level.h>
372 #if __has_include(<android/ndk-version.h>)
373 #include <android/ndk-version.h>
374 #endif
375