1 /* ANSI and traditional C compatability macros 2 Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 3 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010 4 Free Software Foundation, Inc. 5 This file is part of the GNU C Library. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 2 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software 19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ 20 21 /* ANSI and traditional C compatibility macros 22 23 ANSI C is assumed if __STDC__ is #defined. 24 25 Macro ANSI C definition Traditional C definition 26 ----- ---- - ---------- ----------- - ---------- 27 ANSI_PROTOTYPES 1 not defined 28 PTR `void *' `char *' 29 PTRCONST `void *const' `char *' 30 LONG_DOUBLE `long double' `double' 31 const not defined `' 32 volatile not defined `' 33 signed not defined `' 34 VA_START(ap, var) va_start(ap, var) va_start(ap) 35 36 Note that it is safe to write "void foo();" indicating a function 37 with no return value, in all K+R compilers we have been able to test. 38 39 For declaring functions with prototypes, we also provide these: 40 41 PARAMS ((prototype)) 42 -- for functions which take a fixed number of arguments. Use this 43 when declaring the function. When defining the function, write a 44 K+R style argument list. For example: 45 46 char *strcpy PARAMS ((char *dest, char *source)); 47 ... 48 char * 49 strcpy (dest, source) 50 char *dest; 51 char *source; 52 { ... } 53 54 55 VPARAMS ((prototype, ...)) 56 -- for functions which take a variable number of arguments. Use 57 PARAMS to declare the function, VPARAMS to define it. For example: 58 59 int printf PARAMS ((const char *format, ...)); 60 ... 61 int 62 printf VPARAMS ((const char *format, ...)) 63 { 64 ... 65 } 66 67 For writing functions which take variable numbers of arguments, we 68 also provide the VA_OPEN, VA_CLOSE, and VA_FIXEDARG macros. These 69 hide the differences between K+R <varargs.h> and C89 <stdarg.h> more 70 thoroughly than the simple VA_START() macro mentioned above. 71 72 VA_OPEN and VA_CLOSE are used *instead of* va_start and va_end. 73 Immediately after VA_OPEN, put a sequence of VA_FIXEDARG calls 74 corresponding to the list of fixed arguments. Then use va_arg 75 normally to get the variable arguments, or pass your va_list object 76 around. You do not declare the va_list yourself; VA_OPEN does it 77 for you. 78 79 Here is a complete example: 80 81 int 82 printf VPARAMS ((const char *format, ...)) 83 { 84 int result; 85 86 VA_OPEN (ap, format); 87 VA_FIXEDARG (ap, const char *, format); 88 89 result = vfprintf (stdout, format, ap); 90 VA_CLOSE (ap); 91 92 return result; 93 } 94 95 96 You can declare variables either before or after the VA_OPEN, 97 VA_FIXEDARG sequence. Also, VA_OPEN and VA_CLOSE are the beginning 98 and end of a block. They must appear at the same nesting level, 99 and any variables declared after VA_OPEN go out of scope at 100 VA_CLOSE. Unfortunately, with a K+R compiler, that includes the 101 argument list. You can have multiple instances of VA_OPEN/VA_CLOSE 102 pairs in a single function in case you need to traverse the 103 argument list more than once. 104 105 For ease of writing code which uses GCC extensions but needs to be 106 portable to other compilers, we provide the GCC_VERSION macro that 107 simplifies testing __GNUC__ and __GNUC_MINOR__ together, and various 108 wrappers around __attribute__. Also, __extension__ will be #defined 109 to nothing if it doesn't work. See below. 110 111 This header also defines a lot of obsolete macros: 112 CONST, VOLATILE, SIGNED, PROTO, EXFUN, DEFUN, DEFUN_VOID, 113 AND, DOTS, NOARGS. Don't use them. */ 114 115 #ifndef _ANSIDECL_H 116 #define _ANSIDECL_H 1 117 118 #ifdef __cplusplus 119 extern "C" { 120 #endif 121 122 /* Every source file includes this file, 123 so they will all get the switch for lint. */ 124 /* LINTLIBRARY */ 125 126 /* Using MACRO(x,y) in cpp #if conditionals does not work with some 127 older preprocessors. Thus we can't define something like this: 128 129 #define HAVE_GCC_VERSION(MAJOR, MINOR) \ 130 (__GNUC__ > (MAJOR) || (__GNUC__ == (MAJOR) && __GNUC_MINOR__ >= (MINOR))) 131 132 and then test "#if HAVE_GCC_VERSION(2,7)". 133 134 So instead we use the macro below and test it against specific values. */ 135 136 /* This macro simplifies testing whether we are using gcc, and if it 137 is of a particular minimum version. (Both major & minor numbers are 138 significant.) This macro will evaluate to 0 if we are not using 139 gcc at all. */ 140 #ifndef GCC_VERSION 141 #define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__) 142 #endif /* GCC_VERSION */ 143 144 #if defined (__STDC__) || defined(__cplusplus) || defined (_AIX) || (defined (__mips) && defined (_SYSTYPE_SVR4)) || defined(_WIN32) 145 /* All known AIX compilers implement these things (but don't always 146 define __STDC__). The RISC/OS MIPS compiler defines these things 147 in SVR4 mode, but does not define __STDC__. */ 148 /* eraxxon (at) alumni.rice.edu: The Compaq C++ compiler, unlike many other 149 C++ compilers, does not define __STDC__, though it acts as if this 150 was so. (Verified versions: 5.7, 6.2, 6.3, 6.5) */ 151 152 #define ANSI_PROTOTYPES 1 153 #define PTR void * 154 #define PTRCONST void *const 155 #define LONG_DOUBLE long double 156 157 /* PARAMS is often defined elsewhere (e.g. by libintl.h), so wrap it in 158 a #ifndef. */ 159 #ifndef PARAMS 160 #define PARAMS(ARGS) ARGS 161 #endif 162 163 #define VPARAMS(ARGS) ARGS 164 #define VA_START(VA_LIST, VAR) va_start(VA_LIST, VAR) 165 166 /* variadic function helper macros */ 167 /* "struct Qdmy" swallows the semicolon after VA_OPEN/VA_FIXEDARG's 168 use without inhibiting further decls and without declaring an 169 actual variable. */ 170 #define VA_OPEN(AP, VAR) { va_list AP; va_start(AP, VAR); { struct Qdmy 171 #define VA_CLOSE(AP) } va_end(AP); } 172 #define VA_FIXEDARG(AP, T, N) struct Qdmy 173 174 #undef const 175 #undef volatile 176 #undef signed 177 178 /* inline requires special treatment; it's in C99, and GCC >=2.7 supports 179 it too, but it's not in C89. */ 180 #undef inline 181 #if __STDC_VERSION__ >= 199901L || defined(__cplusplus) || (defined(__SUNPRO_C) && defined(__C99FEATURES__)) 182 /* it's a keyword */ 183 #else 184 # if GCC_VERSION >= 2007 185 # define inline __inline__ /* __inline__ prevents -pedantic warnings */ 186 # else 187 # define inline /* nothing */ 188 # endif 189 #endif 190 191 /* These are obsolete. Do not use. */ 192 #ifndef IN_GCC 193 #define CONST const 194 #define VOLATILE volatile 195 #define SIGNED signed 196 197 #define PROTO(type, name, arglist) type name arglist 198 #define EXFUN(name, proto) name proto 199 #define DEFUN(name, arglist, args) name(args) 200 #define DEFUN_VOID(name) name(void) 201 #define AND , 202 #define DOTS , ... 203 #define NOARGS void 204 #endif /* ! IN_GCC */ 205 206 #else /* Not ANSI C. */ 207 208 #undef ANSI_PROTOTYPES 209 #define PTR char * 210 #define PTRCONST PTR 211 #define LONG_DOUBLE double 212 213 #define PARAMS(args) () 214 #define VPARAMS(args) (va_alist) va_dcl 215 #define VA_START(va_list, var) va_start(va_list) 216 217 #define VA_OPEN(AP, VAR) { va_list AP; va_start(AP); { struct Qdmy 218 #define VA_CLOSE(AP) } va_end(AP); } 219 #define VA_FIXEDARG(AP, TYPE, NAME) TYPE NAME = va_arg(AP, TYPE) 220 221 /* some systems define these in header files for non-ansi mode */ 222 #undef const 223 #undef volatile 224 #undef signed 225 #undef inline 226 #define const 227 #define volatile 228 #define signed 229 #define inline 230 231 #ifndef IN_GCC 232 #define CONST 233 #define VOLATILE 234 #define SIGNED 235 236 #define PROTO(type, name, arglist) type name () 237 #define EXFUN(name, proto) name() 238 #define DEFUN(name, arglist, args) name arglist args; 239 #define DEFUN_VOID(name) name() 240 #define AND ; 241 #define DOTS 242 #define NOARGS 243 #endif /* ! IN_GCC */ 244 245 #endif /* ANSI C. */ 246 247 /* Define macros for some gcc attributes. This permits us to use the 248 macros freely, and know that they will come into play for the 249 version of gcc in which they are supported. */ 250 251 #if (GCC_VERSION < 2007) 252 # define __attribute__(x) 253 #endif 254 255 /* Attribute __malloc__ on functions was valid as of gcc 2.96. */ 256 #ifndef ATTRIBUTE_MALLOC 257 # if (GCC_VERSION >= 2096) 258 # define ATTRIBUTE_MALLOC __attribute__ ((__malloc__)) 259 # else 260 # define ATTRIBUTE_MALLOC 261 # endif /* GNUC >= 2.96 */ 262 #endif /* ATTRIBUTE_MALLOC */ 263 264 /* Attributes on labels were valid as of gcc 2.93 and g++ 4.5. For 265 g++ an attribute on a label must be followed by a semicolon. */ 266 #ifndef ATTRIBUTE_UNUSED_LABEL 267 # ifndef __cplusplus 268 # if GCC_VERSION >= 2093 269 # define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED 270 # else 271 # define ATTRIBUTE_UNUSED_LABEL 272 # endif 273 # else 274 # if GCC_VERSION >= 4005 275 # define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED ; 276 # else 277 # define ATTRIBUTE_UNUSED_LABEL 278 # endif 279 # endif 280 #endif 281 282 /* Similarly to ARG_UNUSED below. Prior to GCC 3.4, the C++ frontend 283 couldn't parse attributes placed after the identifier name, and now 284 the entire compiler is built with C++. */ 285 #ifndef ATTRIBUTE_UNUSED 286 #if GCC_VERSION >= 3004 287 # define ATTRIBUTE_UNUSED __attribute__ ((__unused__)) 288 #else 289 #define ATTRIBUTE_UNUSED 290 #endif 291 #endif /* ATTRIBUTE_UNUSED */ 292 293 /* Before GCC 3.4, the C++ frontend couldn't parse attributes placed after the 294 identifier name. */ 295 #if ! defined(__cplusplus) || (GCC_VERSION >= 3004) 296 # define ARG_UNUSED(NAME) NAME ATTRIBUTE_UNUSED 297 #else /* !__cplusplus || GNUC >= 3.4 */ 298 # define ARG_UNUSED(NAME) NAME 299 #endif /* !__cplusplus || GNUC >= 3.4 */ 300 301 #ifndef ATTRIBUTE_NORETURN 302 #define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__)) 303 #endif /* ATTRIBUTE_NORETURN */ 304 305 /* Attribute `nonnull' was valid as of gcc 3.3. */ 306 #ifndef ATTRIBUTE_NONNULL 307 # if (GCC_VERSION >= 3003) 308 # define ATTRIBUTE_NONNULL(m) __attribute__ ((__nonnull__ (m))) 309 # else 310 # define ATTRIBUTE_NONNULL(m) 311 # endif /* GNUC >= 3.3 */ 312 #endif /* ATTRIBUTE_NONNULL */ 313 314 /* Attribute `pure' was valid as of gcc 3.0. */ 315 #ifndef ATTRIBUTE_PURE 316 # if (GCC_VERSION >= 3000) 317 # define ATTRIBUTE_PURE __attribute__ ((__pure__)) 318 # else 319 # define ATTRIBUTE_PURE 320 # endif /* GNUC >= 3.0 */ 321 #endif /* ATTRIBUTE_PURE */ 322 323 /* Use ATTRIBUTE_PRINTF when the format specifier must not be NULL. 324 This was the case for the `printf' format attribute by itself 325 before GCC 3.3, but as of 3.3 we need to add the `nonnull' 326 attribute to retain this behavior. */ 327 #ifndef ATTRIBUTE_PRINTF 328 #define ATTRIBUTE_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n))) ATTRIBUTE_NONNULL(m) 329 #define ATTRIBUTE_PRINTF_1 ATTRIBUTE_PRINTF(1, 2) 330 #define ATTRIBUTE_PRINTF_2 ATTRIBUTE_PRINTF(2, 3) 331 #define ATTRIBUTE_PRINTF_3 ATTRIBUTE_PRINTF(3, 4) 332 #define ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF(4, 5) 333 #define ATTRIBUTE_PRINTF_5 ATTRIBUTE_PRINTF(5, 6) 334 #endif /* ATTRIBUTE_PRINTF */ 335 336 /* Use ATTRIBUTE_FPTR_PRINTF when the format attribute is to be set on 337 a function pointer. Format attributes were allowed on function 338 pointers as of gcc 3.1. */ 339 #ifndef ATTRIBUTE_FPTR_PRINTF 340 # if (GCC_VERSION >= 3001) 341 # define ATTRIBUTE_FPTR_PRINTF(m, n) ATTRIBUTE_PRINTF(m, n) 342 # else 343 # define ATTRIBUTE_FPTR_PRINTF(m, n) 344 # endif /* GNUC >= 3.1 */ 345 # define ATTRIBUTE_FPTR_PRINTF_1 ATTRIBUTE_FPTR_PRINTF(1, 2) 346 # define ATTRIBUTE_FPTR_PRINTF_2 ATTRIBUTE_FPTR_PRINTF(2, 3) 347 # define ATTRIBUTE_FPTR_PRINTF_3 ATTRIBUTE_FPTR_PRINTF(3, 4) 348 # define ATTRIBUTE_FPTR_PRINTF_4 ATTRIBUTE_FPTR_PRINTF(4, 5) 349 # define ATTRIBUTE_FPTR_PRINTF_5 ATTRIBUTE_FPTR_PRINTF(5, 6) 350 #endif /* ATTRIBUTE_FPTR_PRINTF */ 351 352 /* Use ATTRIBUTE_NULL_PRINTF when the format specifier may be NULL. A 353 NULL format specifier was allowed as of gcc 3.3. */ 354 #ifndef ATTRIBUTE_NULL_PRINTF 355 # if (GCC_VERSION >= 3003) 356 # define ATTRIBUTE_NULL_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n))) 357 # else 358 # define ATTRIBUTE_NULL_PRINTF(m, n) 359 # endif /* GNUC >= 3.3 */ 360 # define ATTRIBUTE_NULL_PRINTF_1 ATTRIBUTE_NULL_PRINTF(1, 2) 361 # define ATTRIBUTE_NULL_PRINTF_2 ATTRIBUTE_NULL_PRINTF(2, 3) 362 # define ATTRIBUTE_NULL_PRINTF_3 ATTRIBUTE_NULL_PRINTF(3, 4) 363 # define ATTRIBUTE_NULL_PRINTF_4 ATTRIBUTE_NULL_PRINTF(4, 5) 364 # define ATTRIBUTE_NULL_PRINTF_5 ATTRIBUTE_NULL_PRINTF(5, 6) 365 #endif /* ATTRIBUTE_NULL_PRINTF */ 366 367 /* Attribute `sentinel' was valid as of gcc 3.5. */ 368 #ifndef ATTRIBUTE_SENTINEL 369 # if (GCC_VERSION >= 3005) 370 # define ATTRIBUTE_SENTINEL __attribute__ ((__sentinel__)) 371 # else 372 # define ATTRIBUTE_SENTINEL 373 # endif /* GNUC >= 3.5 */ 374 #endif /* ATTRIBUTE_SENTINEL */ 375 376 377 #ifndef ATTRIBUTE_ALIGNED_ALIGNOF 378 # if (GCC_VERSION >= 3000) 379 # define ATTRIBUTE_ALIGNED_ALIGNOF(m) __attribute__ ((__aligned__ (__alignof__ (m)))) 380 # else 381 # define ATTRIBUTE_ALIGNED_ALIGNOF(m) 382 # endif /* GNUC >= 3.0 */ 383 #endif /* ATTRIBUTE_ALIGNED_ALIGNOF */ 384 385 /* Useful for structures whose layout must much some binary specification 386 regardless of the alignment and padding qualities of the compiler. */ 387 #ifndef ATTRIBUTE_PACKED 388 # define ATTRIBUTE_PACKED __attribute__ ((packed)) 389 #endif 390 391 /* Attribute `hot' and `cold' was valid as of gcc 4.3. */ 392 #ifndef ATTRIBUTE_COLD 393 # if (GCC_VERSION >= 4003) 394 # define ATTRIBUTE_COLD __attribute__ ((__cold__)) 395 # else 396 # define ATTRIBUTE_COLD 397 # endif /* GNUC >= 4.3 */ 398 #endif /* ATTRIBUTE_COLD */ 399 #ifndef ATTRIBUTE_HOT 400 # if (GCC_VERSION >= 4003) 401 # define ATTRIBUTE_HOT __attribute__ ((__hot__)) 402 # else 403 # define ATTRIBUTE_HOT 404 # endif /* GNUC >= 4.3 */ 405 #endif /* ATTRIBUTE_HOT */ 406 407 /* We use __extension__ in some places to suppress -pedantic warnings 408 about GCC extensions. This feature didn't work properly before 409 gcc 2.8. */ 410 #if GCC_VERSION < 2008 411 #define __extension__ 412 #endif 413 414 /* This is used to declare a const variable which should be visible 415 outside of the current compilation unit. Use it as 416 EXPORTED_CONST int i = 1; 417 This is because the semantics of const are different in C and C++. 418 "extern const" is permitted in C but it looks strange, and gcc 419 warns about it when -Wc++-compat is not used. */ 420 #ifdef __cplusplus 421 #define EXPORTED_CONST extern const 422 #else 423 #define EXPORTED_CONST const 424 #endif 425 426 /* Be conservative and only use enum bitfields with C++ or GCC. 427 FIXME: provide a complete autoconf test for buggy enum bitfields. */ 428 429 #ifdef __cplusplus 430 #define ENUM_BITFIELD(TYPE) enum TYPE 431 #elif (GCC_VERSION > 2000) 432 #define ENUM_BITFIELD(TYPE) __extension__ enum TYPE 433 #else 434 #define ENUM_BITFIELD(TYPE) unsigned int 435 #endif 436 437 #ifdef __cplusplus 438 } 439 #endif 440 441 #endif /* ansidecl.h */ 442
