1 /* Copyright (C) 1992-2001, 2002, 2004, 2005, 2006, 2007 2 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <http://www.gnu.org/licenses/>. */ 18 19 #ifndef _SYS_CDEFS_H 20 #define _SYS_CDEFS_H 1 21 22 /* We are almost always included from features.h. */ 23 #ifndef _FEATURES_H 24 # include <features.h> 25 #endif 26 27 /* The GNU libc does not support any K&R compilers or the traditional mode 28 of ISO C compilers anymore. Check for some of the combinations not 29 anymore supported. */ 30 #if defined __GNUC__ && !defined __STDC__ 31 # error "You need a ISO C conforming compiler to use the glibc headers" 32 #endif 33 34 /* Some user header file might have defined this before. */ 35 #undef __P 36 #undef __PMT 37 38 #ifdef __GNUC__ 39 40 /* GCC can always grok prototypes. For C++ programs we add throw() 41 to help it optimize the function calls. But this works only with 42 gcc 2.8.x and egcs. For gcc 3.2 and up we even mark C functions 43 as non-throwing using a function attribute since programs can use 44 the -fexceptions options for C code as well. */ 45 # if !defined __cplusplus && __GNUC_PREREQ (3, 3) 46 # define __THROW __attribute__ ((__nothrow__)) 47 # define __NTH(fct) __attribute__ ((__nothrow__)) fct 48 # else 49 # if defined __cplusplus && __GNUC_PREREQ (2,8) 50 # define __THROW throw () 51 # define __NTH(fct) fct throw () 52 # else 53 # define __THROW 54 # define __NTH(fct) fct 55 # endif 56 # endif 57 58 #else /* Not GCC. */ 59 60 # define __inline /* No inline functions. */ 61 62 # define __THROW 63 # define __NTH(fct) fct 64 65 #endif /* GCC. */ 66 67 /* These two macros are not used in glibc anymore. They are kept here 68 only because some other projects expect the macros to be defined. */ 69 #define __P(args) args 70 #define __PMT(args) args 71 72 /* For these things, GCC behaves the ANSI way normally, 73 and the non-ANSI way under -traditional. */ 74 75 #define __CONCAT(x,y) x ## y 76 #define __STRING(x) #x 77 78 /* This is not a typedef so `const __ptr_t' does the right thing. */ 79 #define __ptr_t void * 80 #define __long_double_t long double 81 82 83 /* C++ needs to know that types and declarations are C, not C++. */ 84 #ifdef __cplusplus 85 # define __BEGIN_DECLS extern "C" { 86 # define __END_DECLS } 87 #else 88 # define __BEGIN_DECLS 89 # define __END_DECLS 90 #endif 91 92 93 /* The standard library needs the functions from the ISO C90 standard 94 in the std namespace. At the same time we want to be safe for 95 future changes and we include the ISO C99 code in the non-standard 96 namespace __c99. The C++ wrapper header take case of adding the 97 definitions to the global namespace. */ 98 #if defined __cplusplus && defined _GLIBCPP_USE_NAMESPACES 99 # define __BEGIN_NAMESPACE_STD namespace std { 100 # define __END_NAMESPACE_STD } 101 # define __USING_NAMESPACE_STD(name) using std::name; 102 # define __BEGIN_NAMESPACE_C99 namespace __c99 { 103 # define __END_NAMESPACE_C99 } 104 # define __USING_NAMESPACE_C99(name) using __c99::name; 105 #else 106 /* For compatibility we do not add the declarations into any 107 namespace. They will end up in the global namespace which is what 108 old code expects. */ 109 # define __BEGIN_NAMESPACE_STD 110 # define __END_NAMESPACE_STD 111 # define __USING_NAMESPACE_STD(name) 112 # define __BEGIN_NAMESPACE_C99 113 # define __END_NAMESPACE_C99 114 # define __USING_NAMESPACE_C99(name) 115 #endif 116 117 118 /* Fortify support. */ 119 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1) 120 #define __bos0(ptr) __builtin_object_size (ptr, 0) 121 122 #if __GNUC_PREREQ (4,3) 123 # define __warndecl(name, msg) \ 124 extern void name (void) __attribute__((__warning__ (msg))) 125 # define __warnattr(msg) __attribute__((__warning__ (msg))) 126 # define __errordecl(name, msg) \ 127 extern void name (void) __attribute__((__error__ (msg))) 128 #else 129 # define __warndecl(name, msg) extern void name (void) 130 # define __warnattr(msg) 131 # define __errordecl(name, msg) extern void name (void) 132 #endif 133 134 /* Support for flexible arrays. */ 135 #if __GNUC_PREREQ (2,97) 136 /* GCC 2.97 supports C99 flexible array members. */ 137 # define __flexarr [] 138 #else 139 # ifdef __GNUC__ 140 # define __flexarr [0] 141 # else 142 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L 143 # define __flexarr [] 144 # else 145 /* Some other non-C99 compiler. Approximate with [1]. */ 146 # define __flexarr [1] 147 # endif 148 # endif 149 #endif 150 151 152 /* __asm__ ("xyz") is used throughout the headers to rename functions 153 at the assembly language level. This is wrapped by the __REDIRECT 154 macro, in order to support compilers that can do this some other 155 way. When compilers don't support asm-names at all, we have to do 156 preprocessor tricks instead (which don't have exactly the right 157 semantics, but it's the best we can do). 158 159 Example: 160 int __REDIRECT(setpgrp, (__pid_t pid, __pid_t pgrp), setpgid); */ 161 162 #if defined __GNUC__ && __GNUC__ >= 2 163 164 # define __REDIRECT(name, proto, alias) name proto __asm__ (__ASMNAME (#alias)) 165 # ifdef __cplusplus 166 # define __REDIRECT_NTH(name, proto, alias) \ 167 name proto __THROW __asm__ (__ASMNAME (#alias)) 168 # else 169 # define __REDIRECT_NTH(name, proto, alias) \ 170 name proto __asm__ (__ASMNAME (#alias)) __THROW 171 # endif 172 # define __ASMNAME(cname) __ASMNAME2 (__USER_LABEL_PREFIX__, cname) 173 # define __ASMNAME2(prefix, cname) __STRING (prefix) cname 174 175 /* 176 #elif __SOME_OTHER_COMPILER__ 177 178 # define __REDIRECT(name, proto, alias) name proto; \ 179 _Pragma("let " #name " = " #alias) 180 */ 181 #endif 182 183 /* GCC has various useful declarations that can be made with the 184 `__attribute__' syntax. All of the ways we use this do fine if 185 they are omitted for compilers that don't understand it. */ 186 #if !defined __GNUC__ || __GNUC__ < 2 187 # define __attribute__(xyz) /* Ignore */ 188 #endif 189 190 /* We make this a no-op unless it can be used as both a variable and 191 a type attribute. gcc 2.8 is known to support both. */ 192 #if __GNUC_PREREQ (2,8) 193 # define __attribute_aligned__(size) __attribute__ ((__aligned__ (size))) 194 #else 195 # define __attribute_aligned__(size) /* Ignore */ 196 #endif 197 198 /* At some point during the gcc 2.96 development the `malloc' attribute 199 for functions was introduced. We don't want to use it unconditionally 200 (although this would be possible) since it generates warnings. */ 201 #if __GNUC_PREREQ (2,96) 202 # define __attribute_malloc__ __attribute__ ((__malloc__)) 203 #else 204 # define __attribute_malloc__ /* Ignore */ 205 #endif 206 207 /* At some point during the gcc 2.96 development the `pure' attribute 208 for functions was introduced. We don't want to use it unconditionally 209 (although this would be possible) since it generates warnings. */ 210 #if __GNUC_PREREQ (2,96) 211 # define __attribute_pure__ __attribute__ ((__pure__)) 212 #else 213 # define __attribute_pure__ /* Ignore */ 214 #endif 215 216 /* At some point during the gcc 3.1 development the `used' attribute 217 for functions was introduced. We don't want to use it unconditionally 218 (although this would be possible) since it generates warnings. */ 219 #if __GNUC_PREREQ (3,1) 220 # define __attribute_used__ __attribute__ ((__used__)) 221 # define __attribute_noinline__ __attribute__ ((__noinline__)) 222 #else 223 # define __attribute_used__ __attribute__ ((__unused__)) 224 # define __attribute_noinline__ /* Ignore */ 225 #endif 226 227 /* gcc allows marking deprecated functions. */ 228 #if __GNUC_PREREQ (3,2) && !defined(__UCLIBC_HIDE_DEPRECATED__) 229 # define __attribute_deprecated__ __attribute__ ((__deprecated__)) 230 #else 231 # define __attribute_deprecated__ /* Ignore */ 232 #endif 233 234 /* At some point during the gcc 2.8 development the `format_arg' attribute 235 for functions was introduced. We don't want to use it unconditionally 236 (although this would be possible) since it generates warnings. 237 If several `format_arg' attributes are given for the same function, in 238 gcc-3.0 and older, all but the last one are ignored. In newer gccs, 239 all designated arguments are considered. */ 240 #if __GNUC_PREREQ (2,8) 241 # define __attribute_format_arg__(x) __attribute__ ((__format_arg__ (x))) 242 #else 243 # define __attribute_format_arg__(x) /* Ignore */ 244 #endif 245 246 /* At some point during the gcc 2.97 development the `strfmon' format 247 attribute for functions was introduced. We don't want to use it 248 unconditionally (although this would be possible) since it 249 generates warnings. */ 250 #if __GNUC_PREREQ (2,97) 251 # define __attribute_format_strfmon__(a,b) \ 252 __attribute__ ((__format__ (__strfmon__, a, b))) 253 #else 254 # define __attribute_format_strfmon__(a,b) /* Ignore */ 255 #endif 256 257 /* The nonull function attribute allows to mark pointer parameters which 258 must not be NULL. */ 259 #if __GNUC_PREREQ (3,3) 260 # define __nonnull(params) __attribute__ ((__nonnull__ params)) 261 #else 262 # define __nonnull(params) 263 #endif 264 265 /* If fortification mode, we warn about unused results of certain 266 function calls which can lead to problems. */ 267 #if __GNUC_PREREQ (3,4) 268 # define __attribute_warn_unused_result__ \ 269 __attribute__ ((__warn_unused_result__)) 270 # if __USE_FORTIFY_LEVEL > 0 271 # define __wur __attribute_warn_unused_result__ 272 # endif 273 #else 274 # define __attribute_warn_unused_result__ /* empty */ 275 #endif 276 #ifndef __wur 277 # define __wur /* Ignore */ 278 #endif 279 280 /* Forces a function to be always inlined. */ 281 #if __GNUC_PREREQ (3,2) 282 # define __always_inline __inline __attribute__ ((__always_inline__)) 283 #else 284 # define __always_inline __inline 285 #endif 286 287 /* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99 288 inline semantics, unless -fgnu89-inline is used. 289 For -std=gnu99, forcing gnu_inline attribute does not change behavior, 290 but may silence spurious warnings (such as in GCC 4.2). */ 291 /* start L4: add clang */ 292 #if !defined __cplusplus || __GNUC_PREREQ (4,3) || defined __clang__ 293 /* L4: original code 294 #if !defined __cplusplus || __GNUC_PREREQ (4,3) 295 */ 296 /* end L4: */ 297 # if defined __GNUC_STDC_INLINE__ || defined __GNUC_GNU_INLINE__ || defined __cplusplus 298 # define __extern_inline extern __inline __attribute__ ((__gnu_inline__)) 299 # if __GNUC_PREREQ (4,3) 300 # define __extern_always_inline \ 301 extern __always_inline __attribute__ ((__gnu_inline__, __artificial__)) 302 # else 303 # define __extern_always_inline \ 304 extern __always_inline __attribute__ ((__gnu_inline__)) 305 # endif 306 # else 307 # define __extern_inline extern __inline 308 # define __extern_always_inline extern __always_inline 309 # endif 310 #endif 311 312 /* GCC 4.3 and above allow passing all anonymous arguments of an 313 __extern_always_inline function to some other vararg function. */ 314 #if __GNUC_PREREQ (4,3) 315 # define __va_arg_pack() __builtin_va_arg_pack () 316 # define __va_arg_pack_len() __builtin_va_arg_pack_len () 317 #endif 318 319 /* It is possible to compile containing GCC extensions even if GCC is 320 run in pedantic mode if the uses are carefully marked using the 321 `__extension__' keyword. But this is not generally available before 322 version 2.8. */ 323 #if !__GNUC_PREREQ (2,8) 324 # define __extension__ /* Ignore */ 325 #endif 326 327 /* __restrict is known in EGCS 1.2 and above. */ 328 #if !__GNUC_PREREQ (2,92) 329 # define __restrict /* Ignore */ 330 #endif 331 332 /* ISO C99 also allows to declare arrays as non-overlapping. The syntax is 333 array_name[restrict] 334 GCC 3.1 supports this. */ 335 #if __GNUC_PREREQ (3,1) && !defined __GNUG__ 336 # define __restrict_arr __restrict 337 #else 338 # ifdef __GNUC__ 339 # define __restrict_arr /* Not supported in old GCC. */ 340 # else 341 # if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L 342 # define __restrict_arr restrict 343 # else 344 /* Some other non-C99 compiler. */ 345 # define __restrict_arr /* Not supported. */ 346 # endif 347 # endif 348 #endif 349 350 #endif /* sys/cdefs.h */ 351