1 /* ANSI and traditional C compatability macros 2 Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001 3 Free Software Foundation, Inc. 4 This file is part of the GNU C Library. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 19 20 /* ANSI and traditional C compatibility macros 21 22 ANSI C is assumed if __STDC__ is #defined. 23 24 Macro ANSI C definition Traditional C definition 25 ----- ---- - ---------- ----------- - ---------- 26 ANSI_PROTOTYPES 1 not defined 27 PTR `void *' `char *' 28 PTRCONST `void *const' `char *' 29 LONG_DOUBLE `long double' `double' 30 const not defined `' 31 volatile not defined `' 32 signed not defined `' 33 VA_START(ap, var) va_start(ap, var) va_start(ap) 34 35 Note that it is safe to write "void foo();" indicating a function 36 with no return value, in all K+R compilers we have been able to test. 37 38 For declaring functions with prototypes, we also provide these: 39 40 PARAMS ((prototype)) 41 -- for functions which take a fixed number of arguments. Use this 42 when declaring the function. When defining the function, write a 43 K+R style argument list. For example: 44 45 char *strcpy PARAMS ((char *dest, char *source)); 46 ... 47 char * 48 strcpy (dest, source) 49 char *dest; 50 char *source; 51 { ... } 52 53 54 VPARAMS ((prototype, ...)) 55 -- for functions which take a variable number of arguments. Use 56 PARAMS to declare the function, VPARAMS to define it. For example: 57 58 int printf PARAMS ((const char *format, ...)); 59 ... 60 int 61 printf VPARAMS ((const char *format, ...)) 62 { 63 ... 64 } 65 66 For writing functions which take variable numbers of arguments, we 67 also provide the VA_OPEN, VA_CLOSE, and VA_FIXEDARG macros. These 68 hide the differences between K+R <varargs.h> and C89 <stdarg.h> more 69 thoroughly than the simple VA_START() macro mentioned above. 70 71 VA_OPEN and VA_CLOSE are used *instead of* va_start and va_end. 72 Immediately after VA_OPEN, put a sequence of VA_FIXEDARG calls 73 corresponding to the list of fixed arguments. Then use va_arg 74 normally to get the variable arguments, or pass your va_list object 75 around. You do not declare the va_list yourself; VA_OPEN does it 76 for you. 77 78 Here is a complete example: 79 80 int 81 printf VPARAMS ((const char *format, ...)) 82 { 83 int result; 84 85 VA_OPEN (ap, format); 86 VA_FIXEDARG (ap, const char *, format); 87 88 result = vfprintf (stdout, format, ap); 89 VA_CLOSE (ap); 90 91 return result; 92 } 93 94 95 You can declare variables either before or after the VA_OPEN, 96 VA_FIXEDARG sequence. Also, VA_OPEN and VA_CLOSE are the beginning 97 and end of a block. They must appear at the same nesting level, 98 and any variables declared after VA_OPEN go out of scope at 99 VA_CLOSE. Unfortunately, with a K+R compiler, that includes the 100 argument list. You can have multiple instances of VA_OPEN/VA_CLOSE 101 pairs in a single function in case you need to traverse the 102 argument list more than once. 103 104 For ease of writing code which uses GCC extensions but needs to be 105 portable to other compilers, we provide the GCC_VERSION macro that 106 simplifies testing __GNUC__ and __GNUC_MINOR__ together, and various 107 wrappers around __attribute__. Also, __extension__ will be #defined 108 to nothing if it doesn't work. See below. 109 110 This header also defines a lot of obsolete macros: 111 CONST, VOLATILE, SIGNED, PROTO, EXFUN, DEFUN, DEFUN_VOID, 112 AND, DOTS, NOARGS. Don't use them. */ 113 114 #ifndef _ANSIDECL_H 115 #define _ANSIDECL_H 1 116 117 /* Every source file includes this file, 118 so they will all get the switch for lint. */ 119 /* LINTLIBRARY */ 120 121 /* Using MACRO(x,y) in cpp #if conditionals does not work with some 122 older preprocessors. Thus we can't define something like this: 123 124 #define HAVE_GCC_VERSION(MAJOR, MINOR) \ 125 (__GNUC__ > (MAJOR) || (__GNUC__ == (MAJOR) && __GNUC_MINOR__ >= (MINOR))) 126 127 and then test "#if HAVE_GCC_VERSION(2,7)". 128 129 So instead we use the macro below and test it against specific values. */ 130 131 /* This macro simplifies testing whether we are using gcc, and if it 132 is of a particular minimum version. (Both major & minor numbers are 133 significant.) This macro will evaluate to 0 if we are not using 134 gcc at all. */ 135 #ifndef GCC_VERSION 136 #define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__) 137 #endif /* GCC_VERSION */ 138 139 #if defined (__STDC__) || defined (_AIX) || (defined (__mips) && defined (_SYSTYPE_SVR4)) || defined(_WIN32) || (defined(__alpha) && defined(__cplusplus)) 140 /* All known AIX compilers implement these things (but don't always 141 define __STDC__). The RISC/OS MIPS compiler defines these things 142 in SVR4 mode, but does not define __STDC__. */ 143 /* eraxxon@alumni.rice.edu: The Compaq C++ compiler, unlike many other 144 C++ compilers, does not define __STDC__, though it acts as if this 145 was so. (Verified versions: 5.7, 6.2, 6.3, 6.5) */ 146 147 #define ANSI_PROTOTYPES 1 148 #define PTR void * 149 #define PTRCONST void *const 150 #define LONG_DOUBLE long double 151 152 #define PARAMS(ARGS) ARGS 153 #define VPARAMS(ARGS) ARGS 154 #define VA_START(VA_LIST, VAR) va_start(VA_LIST, VAR) 155 156 /* variadic function helper macros */ 157 /* "struct Qdmy" swallows the semicolon after VA_OPEN/VA_FIXEDARG's 158 use without inhibiting further decls and without declaring an 159 actual variable. */ 160 #define VA_OPEN(AP, VAR) { va_list AP; va_start(AP, VAR); { struct Qdmy 161 #define VA_CLOSE(AP) } va_end(AP); } 162 #define VA_FIXEDARG(AP, T, N) struct Qdmy 163 164 #undef const 165 #undef volatile 166 #undef signed 167 168 /* inline requires special treatment; it's in C99, and GCC >=2.7 supports 169 it too, but it's not in C89. */ 170 #undef inline 171 #if __STDC_VERSION__ > 199901L 172 /* it's a keyword */ 173 #else 174 # if GCC_VERSION >= 2007 175 # define inline __inline__ /* __inline__ prevents -pedantic warnings */ 176 # else 177 # define inline /* nothing */ 178 # endif 179 #endif 180 181 /* These are obsolete. Do not use. */ 182 #ifndef IN_GCC 183 #define CONST const 184 #define VOLATILE volatile 185 #define SIGNED signed 186 187 #define PROTO(type, name, arglist) type name arglist 188 #define EXFUN(name, proto) name proto 189 #define DEFUN(name, arglist, args) name(args) 190 #define DEFUN_VOID(name) name(void) 191 #define AND , 192 #define DOTS , ... 193 #define NOARGS void 194 #endif /* ! IN_GCC */ 195 196 #else /* Not ANSI C. */ 197 198 #undef ANSI_PROTOTYPES 199 #define PTR char * 200 #define PTRCONST PTR 201 #define LONG_DOUBLE double 202 203 #define PARAMS(args) () 204 #define VPARAMS(args) (va_alist) va_dcl 205 #define VA_START(va_list, var) va_start(va_list) 206 207 #define VA_OPEN(AP, VAR) { va_list AP; va_start(AP); { struct Qdmy 208 #define VA_CLOSE(AP) } va_end(AP); } 209 #define VA_FIXEDARG(AP, TYPE, NAME) TYPE NAME = va_arg(AP, TYPE) 210 211 /* some systems define these in header files for non-ansi mode */ 212 #undef const 213 #undef volatile 214 #undef signed 215 #undef inline 216 #define const 217 #define volatile 218 #define signed 219 #define inline 220 221 #ifndef IN_GCC 222 #define CONST 223 #define VOLATILE 224 #define SIGNED 225 226 #define PROTO(type, name, arglist) type name () 227 #define EXFUN(name, proto) name() 228 #define DEFUN(name, arglist, args) name arglist args; 229 #define DEFUN_VOID(name) name() 230 #define AND ; 231 #define DOTS 232 #define NOARGS 233 #endif /* ! IN_GCC */ 234 235 #endif /* ANSI C. */ 236 237 /* Define macros for some gcc attributes. This permits us to use the 238 macros freely, and know that they will come into play for the 239 version of gcc in which they are supported. */ 240 241 #if (GCC_VERSION < 2007) 242 # define __attribute__(x) 243 #endif 244 245 /* Attribute __malloc__ on functions was valid as of gcc 2.96. */ 246 #ifndef ATTRIBUTE_MALLOC 247 # if (GCC_VERSION >= 2096) 248 # define ATTRIBUTE_MALLOC __attribute__ ((__malloc__)) 249 # else 250 # define ATTRIBUTE_MALLOC 251 # endif /* GNUC >= 2.96 */ 252 #endif /* ATTRIBUTE_MALLOC */ 253 254 /* Attributes on labels were valid as of gcc 2.93. */ 255 #ifndef ATTRIBUTE_UNUSED_LABEL 256 # if (GCC_VERSION >= 2093) 257 # define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED 258 # else 259 # define ATTRIBUTE_UNUSED_LABEL 260 # endif /* GNUC >= 2.93 */ 261 #endif /* ATTRIBUTE_UNUSED_LABEL */ 262 263 #ifndef ATTRIBUTE_UNUSED 264 #define ATTRIBUTE_UNUSED __attribute__ ((__unused__)) 265 #endif /* ATTRIBUTE_UNUSED */ 266 267 #ifndef ATTRIBUTE_NORETURN 268 #define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__)) 269 #endif /* ATTRIBUTE_NORETURN */ 270 271 /* Attribute `nonnull' was valid as of gcc 3.3. */ 272 #ifndef ATTRIBUTE_NONNULL 273 # if (GCC_VERSION >= 3003) 274 # define ATTRIBUTE_NONNULL(m) __attribute__ ((__nonnull__ (m))) 275 # else 276 # define ATTRIBUTE_NONNULL(m) 277 # endif /* GNUC >= 3.3 */ 278 #endif /* ATTRIBUTE_NONNULL */ 279 280 /* Use ATTRIBUTE_PRINTF when the format specifier must not be NULL. 281 This was the case for the `printf' format attribute by itself 282 before GCC 3.3, but as of 3.3 we need to add the `nonnull' 283 attribute to retain this behavior. */ 284 #ifndef ATTRIBUTE_PRINTF 285 #define ATTRIBUTE_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n))) ATTRIBUTE_NONNULL(m) 286 #define ATTRIBUTE_PRINTF_1 ATTRIBUTE_PRINTF(1, 2) 287 #define ATTRIBUTE_PRINTF_2 ATTRIBUTE_PRINTF(2, 3) 288 #define ATTRIBUTE_PRINTF_3 ATTRIBUTE_PRINTF(3, 4) 289 #define ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF(4, 5) 290 #define ATTRIBUTE_PRINTF_5 ATTRIBUTE_PRINTF(5, 6) 291 #endif /* ATTRIBUTE_PRINTF */ 292 293 /* Use ATTRIBUTE_NULL_PRINTF when the format specifier may be NULL. A 294 NULL format specifier was allowed as of gcc 3.3. */ 295 #ifndef ATTRIBUTE_NULL_PRINTF 296 # if (GCC_VERSION >= 3003) 297 # define ATTRIBUTE_NULL_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n))) 298 # else 299 # define ATTRIBUTE_NULL_PRINTF(m, n) 300 # endif /* GNUC >= 3.3 */ 301 # define ATTRIBUTE_NULL_PRINTF_1 ATTRIBUTE_NULL_PRINTF(1, 2) 302 # define ATTRIBUTE_NULL_PRINTF_2 ATTRIBUTE_NULL_PRINTF(2, 3) 303 # define ATTRIBUTE_NULL_PRINTF_3 ATTRIBUTE_NULL_PRINTF(3, 4) 304 # define ATTRIBUTE_NULL_PRINTF_4 ATTRIBUTE_NULL_PRINTF(4, 5) 305 # define ATTRIBUTE_NULL_PRINTF_5 ATTRIBUTE_NULL_PRINTF(5, 6) 306 #endif /* ATTRIBUTE_NULL_PRINTF */ 307 308 /* We use __extension__ in some places to suppress -pedantic warnings 309 about GCC extensions. This feature didn't work properly before 310 gcc 2.8. */ 311 #if GCC_VERSION < 2008 312 #define __extension__ 313 #endif 314 315 #endif /* ansidecl.h */ 316