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/+/main/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 nullness constraints of this parameter or return value are 67 * quite complex. This is used to highlight spots where developers 68 * are encouraged to read relevant manuals or code to understand 69 * the full picture of nullness for this pointer. 70 */ 71 #define __BIONIC_COMPLICATED_NULLNESS _Null_unspecified 72 73 /* 74 * The __CONCAT macro is used to concatenate parts of symbol names, e.g. 75 * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo. 76 * The __CONCAT macro is a bit tricky -- make sure you don't put spaces 77 * in between its arguments. __CONCAT can also concatenate double-quoted 78 * strings produced by the __STRING macro, but this only works with ANSI C. 79 */ 80 81 #define __P(protos) protos /* full-blown ANSI C */ 82 83 #define __CONCAT1(x,y) x ## y 84 #define __CONCAT(x,y) __CONCAT1(x,y) 85 #define ___CONCAT(x,y) __CONCAT(x,y) 86 87 #define __STRING(x) #x 88 #define ___STRING(x) __STRING(x) 89 90 // C++ has `inline` as a keyword, as does C99, but ANSI C (aka C89 aka C90) 91 // does not. Everything accepts the `__inline__` extension though. We could 92 // just use that directly in our own code, but there's historical precedent 93 // for `__inline` meaning it's still used in upstream BSD code (and potentially 94 // downstream in vendor or app code). 95 #define __inline __inline__ 96 97 #define __always_inline __attribute__((__always_inline__)) 98 #define __attribute_const__ __attribute__((__const__)) 99 #define __attribute_pure__ __attribute__((__pure__)) 100 #define __dead __attribute__((__noreturn__)) 101 #define __noreturn __attribute__((__noreturn__)) 102 #define __mallocfunc __attribute__((__malloc__)) 103 #define __packed __attribute__((__packed__)) 104 #define __returns_twice __attribute__((__returns_twice__)) 105 #define __unused __attribute__((__unused__)) 106 #define __used __attribute__((__used__)) 107 108 #define __printflike(x, y) __attribute__((__format__(printf, x, y))) 109 #define __scanflike(x, y) __attribute__((__format__(scanf, x, y))) 110 #define __strftimelike(x) __attribute__((__format__(strftime, x, 0))) 111 112 /* 113 * GNU C version 2.96 added explicit branch prediction so that 114 * the CPU back-end can hint the processor and also so that 115 * code blocks can be reordered such that the predicted path 116 * sees a more linear flow, thus improving cache behavior, etc. 117 * 118 * The following two macros provide us with a way to use this 119 * compiler feature. Use __predict_true() if you expect the expression 120 * to evaluate to true, and __predict_false() if you expect the 121 * expression to evaluate to false. 122 * 123 * A few notes about usage: 124 * 125 * * Generally, __predict_false() error condition checks (unless 126 * you have some _strong_ reason to do otherwise, in which case 127 * document it), and/or __predict_true() `no-error' condition 128 * checks, assuming you want to optimize for the no-error case. 129 * 130 * * Other than that, if you don't know the likelihood of a test 131 * succeeding from empirical or other `hard' evidence, don't 132 * make predictions. 133 * 134 * * These are meant to be used in places that are run `a lot'. 135 * It is wasteful to make predictions in code that is run 136 * seldomly (e.g. at subsystem initialization time) as the 137 * basic block reordering that this affects can often generate 138 * larger code. 139 */ 140 #define __predict_true(exp) __builtin_expect((exp) != 0, 1) 141 #define __predict_false(exp) __builtin_expect((exp) != 0, 0) 142 143 #define __nodiscard __attribute__((__warn_unused_result__)) 144 #define __wur __nodiscard 145 146 #define __errorattr(msg) __attribute__((__unavailable__(msg))) 147 #define __warnattr(msg) __attribute__((__deprecated__(msg))) 148 #define __warnattr_real(msg) __attribute__((__deprecated__(msg))) 149 #define __enable_if(cond, msg) __attribute__((__enable_if__(cond, msg))) 150 #define __clang_error_if(cond, msg) __attribute__((__diagnose_if__(cond, msg, "error"))) 151 #define __clang_warning_if(cond, msg) __attribute__((__diagnose_if__(cond, msg, "warning"))) 152 153 #if defined(ANDROID_STRICT) 154 /* 155 * For things that are sketchy, but not necessarily an error. FIXME: Enable 156 * this. 157 */ 158 # define __warnattr_strict(msg) /* __warnattr(msg) */ 159 #else 160 # define __warnattr_strict(msg) 161 #endif 162 163 /* 164 * Some BSD source needs these macros. 165 * Originally they embedded the rcs versions of each source file 166 * in the generated binary. We strip strings during build anyway,. 167 */ 168 #define __IDSTRING(_prefix,_s) /* nothing */ 169 #define __COPYRIGHT(_s) /* nothing */ 170 #define __FBSDID(_s) /* nothing */ 171 #define __RCSID(_s) /* nothing */ 172 #define __SCCSID(_s) /* nothing */ 173 174 /* 175 * With bionic, you always get all C and POSIX API. 176 * 177 * If you want BSD and/or GNU extensions, _BSD_SOURCE and/or _GNU_SOURCE are 178 * expected to be defined by callers before *any* standard header file is 179 * included. 180 * 181 * In our header files we test against __USE_BSD and __USE_GNU. 182 */ 183 #if defined(_GNU_SOURCE) 184 # define __USE_BSD 1 185 # define __USE_GNU 1 186 #endif 187 188 #if defined(_BSD_SOURCE) 189 # define __USE_BSD 1 190 #endif 191 192 /* 193 * _FILE_OFFSET_BITS 64 support. 194 * See https://android.googlesource.com/platform/bionic/+/main/docs/32-bit-abi.md 195 */ 196 #if !defined(__LP64__) && defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS == 64 197 # define __USE_FILE_OFFSET64 1 198 /* 199 * Note that __RENAME_IF_FILE_OFFSET64 is only valid if the off_t and off64_t 200 * functions were both added at the same API level because if you use this, 201 * you only have one declaration to attach __INTRODUCED_IN to. 202 */ 203 # define __RENAME_IF_FILE_OFFSET64(func) __RENAME(func) 204 #else 205 # define __RENAME_IF_FILE_OFFSET64(func) 206 #endif 207 208 /* glibc compatibility. */ 209 #if defined(__LP64__) 210 #define __WORDSIZE 64 211 #else 212 #define __WORDSIZE 32 213 #endif 214 215 /* 216 * When _FORTIFY_SOURCE is defined, automatic bounds checking is 217 * added to commonly used libc functions. If a buffer overrun is 218 * detected, the program is safely aborted. 219 * 220 * https://android-developers.googleblog.com/2017/04/fortify-in-android.html 221 */ 222 223 #define __BIONIC_FORTIFY_UNKNOWN_SIZE ((size_t) -1) 224 225 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 226 /* FORTIFY can interfere with pattern-matching of clang-tidy/the static analyzer. */ 227 # if !defined(__clang_analyzer__) 228 # define __BIONIC_FORTIFY 1 229 /* ASAN has interceptors that FORTIFY's _chk functions can break. */ 230 # if __has_feature(address_sanitizer) 231 # define __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED 0 232 # else 233 # define __BIONIC_FORTIFY_RUNTIME_CHECKS_ENABLED 1 234 # endif 235 # endif 236 #endif 237 238 // As we move some FORTIFY checks to be always on, __bos needs to be 239 // always available. 240 #if defined(__BIONIC_FORTIFY) 241 # if _FORTIFY_SOURCE == 2 242 # define __bos_level 1 243 # else 244 # define __bos_level 0 245 # endif 246 #else 247 # define __bos_level 0 248 #endif 249 250 #define __bosn(s, n) __builtin_object_size((s), (n)) 251 #define __bos(s) __bosn((s), __bos_level) 252 253 #if defined(__BIONIC_FORTIFY) 254 # define __bos0(s) __bosn((s), 0) 255 # define __pass_object_size_n(n) __attribute__((__pass_object_size__(n))) 256 /* 257 * FORTIFY'ed functions all have either enable_if or pass_object_size, which 258 * makes taking their address impossible. Saying (&read)(foo, bar, baz); will 259 * therefore call the unFORTIFYed version of read. 260 */ 261 # define __call_bypassing_fortify(fn) (&fn) 262 /* 263 * Because clang-FORTIFY uses overloads, we can't mark functions as `extern inline` without making 264 * them available externally. FORTIFY'ed functions try to be as close to possible as 'invisible'; 265 * having stack protectors detracts from that (b/182948263). 266 */ 267 # define __BIONIC_FORTIFY_INLINE static __inline __attribute__((__no_stack_protector__)) \ 268 __always_inline 269 /* 270 * We should use __BIONIC_FORTIFY_VARIADIC instead of __BIONIC_FORTIFY_INLINE 271 * for variadic functions because compilers cannot inline them. 272 * The __always_inline attribute is useless, misleading, and could trigger 273 * clang compiler bug to incorrectly inline variadic functions. 274 */ 275 # define __BIONIC_FORTIFY_VARIADIC static __inline 276 /* Error functions don't have bodies, so they can just be static. */ 277 # define __BIONIC_ERROR_FUNCTION_VISIBILITY static __unused 278 #else 279 /* Further increase sharing for some inline functions */ 280 # define __pass_object_size_n(n) 281 #endif 282 #define __pass_object_size __pass_object_size_n(__bos_level) 283 #define __pass_object_size0 __pass_object_size_n(0) 284 285 /* Intended for use in unevaluated contexts, e.g. diagnose_if conditions. */ 286 #define __bos_unevaluated_lt(bos_val, val) \ 287 ((bos_val) != __BIONIC_FORTIFY_UNKNOWN_SIZE && (bos_val) < (val)) 288 289 #define __bos_unevaluated_le(bos_val, val) \ 290 ((bos_val) != __BIONIC_FORTIFY_UNKNOWN_SIZE && (bos_val) <= (val)) 291 292 /* Intended for use in evaluated contexts. */ 293 #define __bos_dynamic_check_impl_and(bos_val, op, index, cond) \ 294 ((bos_val) == __BIONIC_FORTIFY_UNKNOWN_SIZE || \ 295 (__builtin_constant_p(index) && bos_val op index && (cond))) 296 297 #define __bos_dynamic_check_impl(bos_val, op, index) \ 298 __bos_dynamic_check_impl_and(bos_val, op, index, 1) 299 300 #define __bos_trivially_ge(bos_val, index) __bos_dynamic_check_impl((bos_val), >=, (index)) 301 #define __bos_trivially_gt(bos_val, index) __bos_dynamic_check_impl((bos_val), >, (index)) 302 303 #if defined(__BIONIC_FORTIFY) || defined(__BIONIC_DECLARE_FORTIFY_HELPERS) 304 # define __BIONIC_INCLUDE_FORTIFY_HEADERS 1 305 #endif 306 307 #define __overloadable __attribute__((__overloadable__)) 308 309 #define __diagnose_as_builtin(...) __attribute__((__diagnose_as_builtin__(__VA_ARGS__))) 310 311 /* Used to tag non-static symbols that are private and never exposed by the shared library. */ 312 #define __LIBC_HIDDEN__ __attribute__((__visibility__("hidden"))) 313 314 /* 315 * Used to tag symbols that should be hidden for 64-bit, 316 * but visible to preserve binary compatibility for LP32. 317 */ 318 #ifdef __LP64__ 319 #define __LIBC32_LEGACY_PUBLIC__ __attribute__((__visibility__("hidden"))) 320 #else 321 #define __LIBC32_LEGACY_PUBLIC__ __attribute__((__visibility__("default"))) 322 #endif 323 324 /* Used to rename functions so that the compiler emits a call to 'x' rather than the function this was applied to. */ 325 #define __RENAME(x) __asm__(#x) 326 327 /* 328 * Used when we need to check for overflow when multiplying x and y. This 329 * should only be used where __builtin_umull_overflow can not work, because it makes 330 * assumptions that __builtin_umull_overflow doesn't (x and y are positive, ...), 331 * *and* doesn't make use of compiler intrinsics, so it's probably slower than 332 * __builtin_umull_overflow. 333 */ 334 #define __unsafe_check_mul_overflow(x, y) ((__SIZE_TYPE__)-1 / (x) < (y)) 335 336 #include <android/versioning.h> 337 #include <android/api-level.h> 338 #if __has_include(<android/ndk-version.h>) 339 #include <android/ndk-version.h> 340 #endif 341