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
4 Free Software Foundation, Inc.
5 This file is part of the GNU C Library.
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.
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.
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. */
21 /* ANSI and traditional C compatibility macros
23 ANSI C is assumed if __STDC__ is #defined.
25 Macro ANSI C definition Traditional C definition
26 ----- ---- - ---------- ----------- - ----------
27 ANSI_PROTOTYPES 1 not defined
29 PTRCONST `void *const' `char *'
30 LONG_DOUBLE `long double' `double'
32 volatile not defined `'
34 VA_START(ap, var) va_start(ap, var) va_start(ap)
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.
39 For declaring functions with prototypes, we also provide these:
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:
46 char *strcpy PARAMS ((char *dest, char *source));
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:
59 int printf PARAMS ((const char *format, ...));
62 printf VPARAMS ((const char *format, ...))
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.
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
79 Here is a complete example:
82 printf VPARAMS ((const char *format, ...))
87 VA_FIXEDARG (ap, const char *, format);
89 result = vfprintf (stdout, format, ap);
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.
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.
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. */
116 #define _ANSIDECL_H 1
122 /* Every source file includes this file,
123 so they will all get the switch for lint. */
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:
129 #define HAVE_GCC_VERSION(MAJOR, MINOR) \
130 (__GNUC__ > (MAJOR) || (__GNUC__ == (MAJOR) && __GNUC_MINOR__ >= (MINOR)))
132 and then test "#if HAVE_GCC_VERSION(2,7)".
134 So instead we use the macro below and test it against specific values. */
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
141 #define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__)
142 #endif /* GCC_VERSION */
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@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) */
152 #define ANSI_PROTOTYPES 1
154 #define PTRCONST void *const
155 #define LONG_DOUBLE long double
157 /* PARAMS is often defined elsewhere (e.g. by libintl.h), so wrap it in
160 #define PARAMS(ARGS) ARGS
163 #define VPARAMS(ARGS) ARGS
164 #define VA_START(VA_LIST, VAR) va_start(VA_LIST, VAR)
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
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
178 /* inline requires special treatment; it's in C99, and GCC >=2.7 supports
179 it too, but it's not in C89. */
181 #if __STDC_VERSION__ > 199901L || defined(__cplusplus)
184 # if GCC_VERSION >= 2007
185 # define inline __inline__ /* __inline__ prevents -pedantic warnings */
187 # define inline /* nothing */
191 /* These are obsolete. Do not use. */
194 #define VOLATILE volatile
195 #define SIGNED signed
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)
204 #endif /* ! IN_GCC */
206 #else /* Not ANSI C. */
208 #undef ANSI_PROTOTYPES
211 #define LONG_DOUBLE double
213 #define PARAMS(args) ()
214 #define VPARAMS(args) (va_alist) va_dcl
215 #define VA_START(va_list, var) va_start(va_list)
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)
221 /* some systems define these in header files for non-ansi mode */
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()
243 #endif /* ! IN_GCC */
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. */
251 #if (GCC_VERSION < 2007)
252 # define __attribute__(x)
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__))
260 # define ATTRIBUTE_MALLOC
261 # endif /* GNUC >= 2.96 */
262 #endif /* ATTRIBUTE_MALLOC */
264 /* Attributes on labels were valid as of gcc 2.93. */
265 #ifndef ATTRIBUTE_UNUSED_LABEL
266 # if (!defined (__cplusplus) && GCC_VERSION >= 2093)
267 # define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED
269 # define ATTRIBUTE_UNUSED_LABEL
270 # endif /* !__cplusplus && GNUC >= 2.93 */
271 #endif /* ATTRIBUTE_UNUSED_LABEL */
273 #ifndef ATTRIBUTE_UNUSED
274 #define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
275 #endif /* ATTRIBUTE_UNUSED */
277 /* Before GCC 3.4, the C++ frontend couldn't parse attributes placed after the
279 #if ! defined(__cplusplus) || (GCC_VERSION >= 3004)
280 # define ARG_UNUSED(NAME) NAME ATTRIBUTE_UNUSED
281 #else /* !__cplusplus || GNUC >= 3.4 */
282 # define ARG_UNUSED(NAME) NAME
283 #endif /* !__cplusplus || GNUC >= 3.4 */
285 #ifndef ATTRIBUTE_NORETURN
286 #define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
287 #endif /* ATTRIBUTE_NORETURN */
289 /* Attribute `nonnull' was valid as of gcc 3.3. */
290 #ifndef ATTRIBUTE_NONNULL
291 # if (GCC_VERSION >= 3003)
292 # define ATTRIBUTE_NONNULL(m) __attribute__ ((__nonnull__ (m)))
294 # define ATTRIBUTE_NONNULL(m)
295 # endif /* GNUC >= 3.3 */
296 #endif /* ATTRIBUTE_NONNULL */
298 /* Attribute `pure' was valid as of gcc 3.0. */
299 #ifndef ATTRIBUTE_PURE
300 # if (GCC_VERSION >= 3000)
301 # define ATTRIBUTE_PURE __attribute__ ((__pure__))
303 # define ATTRIBUTE_PURE
304 # endif /* GNUC >= 3.0 */
305 #endif /* ATTRIBUTE_PURE */
307 /* Use ATTRIBUTE_PRINTF when the format specifier must not be NULL.
308 This was the case for the `printf' format attribute by itself
309 before GCC 3.3, but as of 3.3 we need to add the `nonnull'
310 attribute to retain this behavior. */
311 #ifndef ATTRIBUTE_PRINTF
312 #define ATTRIBUTE_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n))) ATTRIBUTE_NONNULL(m)
313 #define ATTRIBUTE_PRINTF_1 ATTRIBUTE_PRINTF(1, 2)
314 #define ATTRIBUTE_PRINTF_2 ATTRIBUTE_PRINTF(2, 3)
315 #define ATTRIBUTE_PRINTF_3 ATTRIBUTE_PRINTF(3, 4)
316 #define ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF(4, 5)
317 #define ATTRIBUTE_PRINTF_5 ATTRIBUTE_PRINTF(5, 6)
318 #endif /* ATTRIBUTE_PRINTF */
320 /* Use ATTRIBUTE_FPTR_PRINTF when the format attribute is to be set on
321 a function pointer. Format attributes were allowed on function
322 pointers as of gcc 3.1. */
323 #ifndef ATTRIBUTE_FPTR_PRINTF
324 # if (GCC_VERSION >= 3001)
325 # define ATTRIBUTE_FPTR_PRINTF(m, n) ATTRIBUTE_PRINTF(m, n)
327 # define ATTRIBUTE_FPTR_PRINTF(m, n)
328 # endif /* GNUC >= 3.1 */
329 # define ATTRIBUTE_FPTR_PRINTF_1 ATTRIBUTE_FPTR_PRINTF(1, 2)
330 # define ATTRIBUTE_FPTR_PRINTF_2 ATTRIBUTE_FPTR_PRINTF(2, 3)
331 # define ATTRIBUTE_FPTR_PRINTF_3 ATTRIBUTE_FPTR_PRINTF(3, 4)
332 # define ATTRIBUTE_FPTR_PRINTF_4 ATTRIBUTE_FPTR_PRINTF(4, 5)
333 # define ATTRIBUTE_FPTR_PRINTF_5 ATTRIBUTE_FPTR_PRINTF(5, 6)
334 #endif /* ATTRIBUTE_FPTR_PRINTF */
336 /* Use ATTRIBUTE_NULL_PRINTF when the format specifier may be NULL. A
337 NULL format specifier was allowed as of gcc 3.3. */
338 #ifndef ATTRIBUTE_NULL_PRINTF
339 # if (GCC_VERSION >= 3003)
340 # define ATTRIBUTE_NULL_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n)))
342 # define ATTRIBUTE_NULL_PRINTF(m, n)
343 # endif /* GNUC >= 3.3 */
344 # define ATTRIBUTE_NULL_PRINTF_1 ATTRIBUTE_NULL_PRINTF(1, 2)
345 # define ATTRIBUTE_NULL_PRINTF_2 ATTRIBUTE_NULL_PRINTF(2, 3)
346 # define ATTRIBUTE_NULL_PRINTF_3 ATTRIBUTE_NULL_PRINTF(3, 4)
347 # define ATTRIBUTE_NULL_PRINTF_4 ATTRIBUTE_NULL_PRINTF(4, 5)
348 # define ATTRIBUTE_NULL_PRINTF_5 ATTRIBUTE_NULL_PRINTF(5, 6)
349 #endif /* ATTRIBUTE_NULL_PRINTF */
351 /* Attribute `sentinel' was valid as of gcc 3.5. */
352 #ifndef ATTRIBUTE_SENTINEL
353 # if (GCC_VERSION >= 3005)
354 # define ATTRIBUTE_SENTINEL __attribute__ ((__sentinel__))
356 # define ATTRIBUTE_SENTINEL
357 # endif /* GNUC >= 3.5 */
358 #endif /* ATTRIBUTE_SENTINEL */
361 #ifndef ATTRIBUTE_ALIGNED_ALIGNOF
362 # if (GCC_VERSION >= 3000)
363 # define ATTRIBUTE_ALIGNED_ALIGNOF(m) __attribute__ ((__aligned__ (__alignof__ (m))))
365 # define ATTRIBUTE_ALIGNED_ALIGNOF(m)
366 # endif /* GNUC >= 3.0 */
367 #endif /* ATTRIBUTE_ALIGNED_ALIGNOF */
369 /* Useful for structures whose layout must much some binary specification
370 regardless of the alignment and padding qualities of the compiler. */
371 #ifndef ATTRIBUTE_PACKED
372 # define ATTRIBUTE_PACKED __attribute__ ((packed))
375 /* Attribute `hot' and `cold' was valid as of gcc 4.3. */
376 #ifndef ATTRIBUTE_COLD
377 # if (GCC_VERSION >= 4003)
378 # define ATTRIBUTE_COLD __attribute__ ((__cold__))
380 # define ATTRIBUTE_COLD
381 # endif /* GNUC >= 4.3 */
382 #endif /* ATTRIBUTE_COLD */
383 #ifndef ATTRIBUTE_HOT
384 # if (GCC_VERSION >= 4003)
385 # define ATTRIBUTE_HOT __attribute__ ((__hot__))
387 # define ATTRIBUTE_HOT
388 # endif /* GNUC >= 4.3 */
389 #endif /* ATTRIBUTE_HOT */
391 /* We use __extension__ in some places to suppress -pedantic warnings
392 about GCC extensions. This feature didn't work properly before
394 #if GCC_VERSION < 2008
395 #define __extension__
398 /* This is used to declare a const variable which should be visible
399 outside of the current compilation unit. Use it as
400 EXPORTED_CONST int i = 1;
401 This is because the semantics of const are different in C and C++.
402 "extern const" is permitted in C but it looks strange, and gcc
403 warns about it when -Wc++-compat is not used. */
405 #define EXPORTED_CONST extern const
407 #define EXPORTED_CONST const
414 #endif /* ansidecl.h */