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
7This program is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2 of the License, or
10(at your option) any later version.
11
12This program is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with this program; if not, write to the Free Software
19Foundation, 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
119extern "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
132and then test "#if HAVE_GCC_VERSION(2,7)".
133
134So 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@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#ifndef ATTRIBUTE_UNUSED
283#define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
284#endif /* ATTRIBUTE_UNUSED */
285
286/* Before GCC 3.4, the C++ frontend couldn't parse attributes placed after the
287   identifier name.  */
288#if ! defined(__cplusplus) || (GCC_VERSION >= 3004)
289# define ARG_UNUSED(NAME) NAME ATTRIBUTE_UNUSED
290#else /* !__cplusplus || GNUC >= 3.4 */
291# define ARG_UNUSED(NAME) NAME
292#endif /* !__cplusplus || GNUC >= 3.4 */
293
294#ifndef ATTRIBUTE_NORETURN
295#define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
296#endif /* ATTRIBUTE_NORETURN */
297
298/* Attribute `nonnull' was valid as of gcc 3.3.  */
299#ifndef ATTRIBUTE_NONNULL
300# if (GCC_VERSION >= 3003)
301#  define ATTRIBUTE_NONNULL(m) __attribute__ ((__nonnull__ (m)))
302# else
303#  define ATTRIBUTE_NONNULL(m)
304# endif /* GNUC >= 3.3 */
305#endif /* ATTRIBUTE_NONNULL */
306
307/* Attribute `pure' was valid as of gcc 3.0.  */
308#ifndef ATTRIBUTE_PURE
309# if (GCC_VERSION >= 3000)
310#  define ATTRIBUTE_PURE __attribute__ ((__pure__))
311# else
312#  define ATTRIBUTE_PURE
313# endif /* GNUC >= 3.0 */
314#endif /* ATTRIBUTE_PURE */
315
316/* Use ATTRIBUTE_PRINTF when the format specifier must not be NULL.
317   This was the case for the `printf' format attribute by itself
318   before GCC 3.3, but as of 3.3 we need to add the `nonnull'
319   attribute to retain this behavior.  */
320#ifndef ATTRIBUTE_PRINTF
321#define ATTRIBUTE_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n))) ATTRIBUTE_NONNULL(m)
322#define ATTRIBUTE_PRINTF_1 ATTRIBUTE_PRINTF(1, 2)
323#define ATTRIBUTE_PRINTF_2 ATTRIBUTE_PRINTF(2, 3)
324#define ATTRIBUTE_PRINTF_3 ATTRIBUTE_PRINTF(3, 4)
325#define ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF(4, 5)
326#define ATTRIBUTE_PRINTF_5 ATTRIBUTE_PRINTF(5, 6)
327#endif /* ATTRIBUTE_PRINTF */
328
329/* Use ATTRIBUTE_FPTR_PRINTF when the format attribute is to be set on
330   a function pointer.  Format attributes were allowed on function
331   pointers as of gcc 3.1.  */
332#ifndef ATTRIBUTE_FPTR_PRINTF
333# if (GCC_VERSION >= 3001)
334#  define ATTRIBUTE_FPTR_PRINTF(m, n) ATTRIBUTE_PRINTF(m, n)
335# else
336#  define ATTRIBUTE_FPTR_PRINTF(m, n)
337# endif /* GNUC >= 3.1 */
338# define ATTRIBUTE_FPTR_PRINTF_1 ATTRIBUTE_FPTR_PRINTF(1, 2)
339# define ATTRIBUTE_FPTR_PRINTF_2 ATTRIBUTE_FPTR_PRINTF(2, 3)
340# define ATTRIBUTE_FPTR_PRINTF_3 ATTRIBUTE_FPTR_PRINTF(3, 4)
341# define ATTRIBUTE_FPTR_PRINTF_4 ATTRIBUTE_FPTR_PRINTF(4, 5)
342# define ATTRIBUTE_FPTR_PRINTF_5 ATTRIBUTE_FPTR_PRINTF(5, 6)
343#endif /* ATTRIBUTE_FPTR_PRINTF */
344
345/* Use ATTRIBUTE_NULL_PRINTF when the format specifier may be NULL.  A
346   NULL format specifier was allowed as of gcc 3.3.  */
347#ifndef ATTRIBUTE_NULL_PRINTF
348# if (GCC_VERSION >= 3003)
349#  define ATTRIBUTE_NULL_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n)))
350# else
351#  define ATTRIBUTE_NULL_PRINTF(m, n)
352# endif /* GNUC >= 3.3 */
353# define ATTRIBUTE_NULL_PRINTF_1 ATTRIBUTE_NULL_PRINTF(1, 2)
354# define ATTRIBUTE_NULL_PRINTF_2 ATTRIBUTE_NULL_PRINTF(2, 3)
355# define ATTRIBUTE_NULL_PRINTF_3 ATTRIBUTE_NULL_PRINTF(3, 4)
356# define ATTRIBUTE_NULL_PRINTF_4 ATTRIBUTE_NULL_PRINTF(4, 5)
357# define ATTRIBUTE_NULL_PRINTF_5 ATTRIBUTE_NULL_PRINTF(5, 6)
358#endif /* ATTRIBUTE_NULL_PRINTF */
359
360/* Attribute `sentinel' was valid as of gcc 3.5.  */
361#ifndef ATTRIBUTE_SENTINEL
362# if (GCC_VERSION >= 3005)
363#  define ATTRIBUTE_SENTINEL __attribute__ ((__sentinel__))
364# else
365#  define ATTRIBUTE_SENTINEL
366# endif /* GNUC >= 3.5 */
367#endif /* ATTRIBUTE_SENTINEL */
368
369
370#ifndef ATTRIBUTE_ALIGNED_ALIGNOF
371# if (GCC_VERSION >= 3000)
372#  define ATTRIBUTE_ALIGNED_ALIGNOF(m) __attribute__ ((__aligned__ (__alignof__ (m))))
373# else
374#  define ATTRIBUTE_ALIGNED_ALIGNOF(m)
375# endif /* GNUC >= 3.0 */
376#endif /* ATTRIBUTE_ALIGNED_ALIGNOF */
377
378/* Useful for structures whose layout must much some binary specification
379   regardless of the alignment and padding qualities of the compiler.  */
380#ifndef ATTRIBUTE_PACKED
381# define ATTRIBUTE_PACKED __attribute__ ((packed))
382#endif
383
384/* Attribute `hot' and `cold' was valid as of gcc 4.3.  */
385#ifndef ATTRIBUTE_COLD
386# if (GCC_VERSION >= 4003)
387#  define ATTRIBUTE_COLD __attribute__ ((__cold__))
388# else
389#  define ATTRIBUTE_COLD
390# endif /* GNUC >= 4.3 */
391#endif /* ATTRIBUTE_COLD */
392#ifndef ATTRIBUTE_HOT
393# if (GCC_VERSION >= 4003)
394#  define ATTRIBUTE_HOT __attribute__ ((__hot__))
395# else
396#  define ATTRIBUTE_HOT
397# endif /* GNUC >= 4.3 */
398#endif /* ATTRIBUTE_HOT */
399
400/* We use __extension__ in some places to suppress -pedantic warnings
401   about GCC extensions.  This feature didn't work properly before
402   gcc 2.8.  */
403#if GCC_VERSION < 2008
404#define __extension__
405#endif
406
407/* This is used to declare a const variable which should be visible
408   outside of the current compilation unit.  Use it as
409     EXPORTED_CONST int i = 1;
410   This is because the semantics of const are different in C and C++.
411   "extern const" is permitted in C but it looks strange, and gcc
412   warns about it when -Wc++-compat is not used.  */
413#ifdef __cplusplus
414#define EXPORTED_CONST extern const
415#else
416#define EXPORTED_CONST const
417#endif
418
419/* Be conservative and only use enum bitfields with C++ or GCC.
420   FIXME: provide a complete autoconf test for buggy enum bitfields.  */
421
422#ifdef __cplusplus
423#define ENUM_BITFIELD(TYPE) enum TYPE
424#elif (GCC_VERSION > 2000)
425#define ENUM_BITFIELD(TYPE) __extension__ enum TYPE
426#else
427#define ENUM_BITFIELD(TYPE) unsigned int
428#endif
429
430#ifdef __cplusplus
431}
432#endif
433
434#endif	/* ansidecl.h	*/
435