[glibc.git] / features.h

/* Copyright (C) 1991, 92, 93, 95, 96 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#ifndef	_FEATURES_H

#define	_FEATURES_H	1

/* These are defined by the user (or the compiler)
   to specify the desired environment:

   __STRICT_ANSI__	ANSI Standard C.
   _POSIX_SOURCE	IEEE Std 1003.1.
   _POSIX_C_SOURCE	If ==1, like _POSIX_SOURCE; if ==2 add IEEE Std 1003.2.
   _BSD_SOURCE		ANSI, POSIX, and 4.3BSD things.
   _SVID_SOURCE		ANSI, POSIX, and SVID things.
   _GNU_SOURCE		All of the above, plus GNU extensions.

   The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
   If none of these are defined, the default is all but _GNU_SOURCE.
   If more than one of these are defined, they accumulate.
   For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
   together give you ANSI C, 1003.1, and 1003.2, but nothing else.

   These are defined by this file and are used by the
   header files to decide what to declare or define:

   __USE_POSIX		Define IEEE Std 1003.1 things.
   __USE_POSIX2		Define IEEE Std 1003.2 things.
   __USE_BSD		Define 4.3BSD things.
   __USE_SVID		Define SVID things.
   __USE_MISC		Define things common to BSD and System V Unix.
   __USE_GNU		Define GNU extensions.
   __USE_REENTRANT	Define reentrant/thread-safe *_r functions.
   __FAVOR_BSD		Favor 4.3BSD things in cases of conflict.

   The macro `__GNU_LIBRARY__' is defined by this file unconditionally.

   All macros defined by this file are defined as 1.
   All macros listed above as possibly being defined by this file are
   explicitly undefined if they are not explicitly defined.
   Feature-test macros that are not defined by the user or compiler
   but are implied by the other feature-test macros defined (or by the
   lack of any definitions) are defined by the file.  */


/* Undefine everything, so we get a clean slate.  */
#undef	__USE_POSIX
#undef	__USE_POSIX2
#undef	__USE_BSD
#undef	__USE_SVID
#undef	__USE_MISC
#undef	__USE_GNU
#undef	__USE_REENTRANT
#undef	__FAVOR_BSD


/* Always use ANSI things.  */
#define	__USE_ANSI	1


/* If _BSD_SOURCE was defined by the user, favor BSD over POSIX.  */
#if defined (_BSD_SOURCE) && \
    !(defined (_POSIX_SOURCE) || defined (_POSIX_C_SOURCE) || \
      defined (_GNU_SOURCE) || defined (_SVID_SOURCE))
#define	__FAVOR_BSD	1
#endif


/* If nothing (other than _GNU_SOURCE) is defined,
   define _BSD_SOURCE and _SVID_SOURCE.  */
#if (!defined(__STRICT_ANSI__) && !defined(_POSIX_SOURCE) && \
     !defined(_POSIX_C_SOURCE) && !defined(_BSD_SOURCE) && \
     !defined(_SVID_SOURCE))
#define	_BSD_SOURCE	1
#define	_SVID_SOURCE	1
#endif

/* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2.  */
#if (!defined(__STRICT_ANSI__) && !defined(_POSIX_SOURCE) && \
     !defined(_POSIX_C_SOURCE))
#define	_POSIX_SOURCE	1
#define	_POSIX_C_SOURCE	2
#endif

#if	defined(_POSIX_SOURCE) || _POSIX_C_SOURCE >= 1
#define	__USE_POSIX	1
#endif

#if	defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 2
#define	__USE_POSIX2	1
#endif

#if defined(_BSD_SOURCE) || defined(_SVID_SOURCE)
#define	__USE_MISC	1
#endif

#ifdef	_BSD_SOURCE
#define	__USE_BSD	1
#endif

#ifdef	_SVID_SOURCE
#define	__USE_SVID	1
#endif

#ifdef	_GNU_SOURCE
#define	__USE_GNU	1
#endif

#if defined (__USE_GNU) || defined (__USE_MISC)
#define __USE_REENTRANT	1
#endif


/* This macro indicates that the installed library is the GNU C Library.
   Its value must be incremented whenever any existing library interface
   changes such that callers must be recompiled with the new header files.
   This value should always coincide with the major version number used for
   the shared C library corresponding to this set of header files.  */

#undef	__GNU_LIBRARY__
#define	__GNU_LIBRARY__	5


#if	!defined(__GNUC__) || __GNUC__ < 2
/* In GCC version 2, (__extension__ EXPR) will not complain
   about GCC extensions used in EXPR under -ansi or -pedantic.  */
#define	__extension__
#endif


/* This is here only because every header file already includes this one.  */
#include <sys/cdefs.h>

/* This is here only because every header file already includes this one.  */
#ifndef _LIBC
/* Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
   <stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
   which will always return failure (and set errno to ENOSYS).

   We avoid including <stubs.h> when compiling the C library itself to
   avoid a dependency loop.  stubs.h depends on every object file.  If
   this #include were done for the library source code, then every object
   file would depend on stubs.h.  */

#include <stubs.h>
#endif

#endif	/* __features.h  */
Commit	Line	Data
d3669add	1	/* Copyright (C) 1991, 92, 93, 95, 96 Free Software Foundation, Inc.
28f540f4 RM	2	This file is part of the GNU C Library.
	3
	4	The GNU C Library is free software; you can redistribute it and/or
	5	modify it under the terms of the GNU Library General Public License as
	6	published by the Free Software Foundation; either version 2 of the
	7	License, or (at your option) any later version.
	8
	9	The GNU C Library is distributed in the hope that it will be useful,
	10	but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	12	Library General Public License for more details.
	13
	14	You should have received a copy of the GNU Library General Public
	15	License along with the GNU C Library; see the file COPYING.LIB. If
	16	not, write to the Free Software Foundation, Inc., 675 Mass Ave,
	17	Cambridge, MA 02139, USA. */
	18
	19	#ifndef _FEATURES_H
	20
	21	#define _FEATURES_H 1
	22
	23	/* These are defined by the user (or the compiler)
	24	to specify the desired environment:
	25
	26	__STRICT_ANSI__ ANSI Standard C.
	27	_POSIX_SOURCE IEEE Std 1003.1.
	28	_POSIX_C_SOURCE If ==1, like _POSIX_SOURCE; if ==2 add IEEE Std 1003.2.
	29	_BSD_SOURCE ANSI, POSIX, and 4.3BSD things.
	30	_SVID_SOURCE ANSI, POSIX, and SVID things.
	31	_GNU_SOURCE All of the above, plus GNU extensions.
	32
	33	The `-ansi' switch to the GNU C compiler defines __STRICT_ANSI__.
d3669add	34	If none of these are defined, the default is all but _GNU_SOURCE.
28f540f4 RM	35	If more than one of these are defined, they accumulate.
	36	For example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE
	37	together give you ANSI C, 1003.1, and 1003.2, but nothing else.
	38
	39	These are defined by this file and are used by the
	40	header files to decide what to declare or define:
	41
	42	__USE_POSIX Define IEEE Std 1003.1 things.
	43	__USE_POSIX2 Define IEEE Std 1003.2 things.
	44	__USE_BSD Define 4.3BSD things.
	45	__USE_SVID Define SVID things.
	46	__USE_MISC Define things common to BSD and System V Unix.
	47	__USE_GNU Define GNU extensions.
aa910907	48	__USE_REENTRANT Define reentrant/thread-safe *_r functions.
28f540f4 RM	49	__FAVOR_BSD Favor 4.3BSD things in cases of conflict.
	50
	51	The macro `__GNU_LIBRARY__' is defined by this file unconditionally.
	52
	53	All macros defined by this file are defined as 1.
	54	All macros listed above as possibly being defined by this file are
	55	explicitly undefined if they are not explicitly defined.
	56	Feature-test macros that are not defined by the user or compiler
	57	but are implied by the other feature-test macros defined (or by the
	58	lack of any definitions) are defined by the file. */
	59
	60
	61	/* Undefine everything, so we get a clean slate. */
	62	#undef __USE_POSIX
	63	#undef __USE_POSIX2
	64	#undef __USE_BSD
	65	#undef __USE_SVID
	66	#undef __USE_MISC
	67	#undef __USE_GNU
aa910907	68	#undef __USE_REENTRANT
28f540f4 RM	69	#undef __FAVOR_BSD
	70
	71
28f540f4 RM	72	/* Always use ANSI things. */
	73	#define __USE_ANSI 1
	74
	75
	76	/* If _BSD_SOURCE was defined by the user, favor BSD over POSIX. */
d3669add	77	#if defined (_BSD_SOURCE) && \
4d585333 RM	78	!(defined (_POSIX_SOURCE) \|\| defined (_POSIX_C_SOURCE) \|\| \
4d585333 RM	79	defined (_GNU_SOURCE) \|\| defined (_SVID_SOURCE))
28f540f4 RM	80	#define __FAVOR_BSD 1
	81	#endif
	82
	83
	84	/* If nothing (other than _GNU_SOURCE) is defined,
	85	define _BSD_SOURCE and _SVID_SOURCE. */
	86	#if (!defined(__STRICT_ANSI__) && !defined(_POSIX_SOURCE) && \
	87	!defined(_POSIX_C_SOURCE) && !defined(_BSD_SOURCE) && \
	88	!defined(_SVID_SOURCE))
	89	#define _BSD_SOURCE 1
	90	#define _SVID_SOURCE 1
	91	#endif
	92
	93	/* If none of the ANSI/POSIX macros are defined, use POSIX.1 and POSIX.2. */
	94	#if (!defined(__STRICT_ANSI__) && !defined(_POSIX_SOURCE) && \
	95	!defined(_POSIX_C_SOURCE))
	96	#define _POSIX_SOURCE 1
	97	#define _POSIX_C_SOURCE 2
	98	#endif
	99
	100	#if defined(_POSIX_SOURCE) \|\| _POSIX_C_SOURCE >= 1
	101	#define __USE_POSIX 1
	102	#endif
	103
	104	#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 2
	105	#define __USE_POSIX2 1
	106	#endif
	107
	108	#if defined(_BSD_SOURCE) \|\| defined(_SVID_SOURCE)
	109	#define __USE_MISC 1
	110	#endif
	111
	112	#ifdef _BSD_SOURCE
	113	#define __USE_BSD 1
	114	#endif
	115
	116	#ifdef _SVID_SOURCE
	117	#define __USE_SVID 1
	118	#endif
	119
	120	#ifdef _GNU_SOURCE
	121	#define __USE_GNU 1
	122	#endif
	123
aa910907 RM	124	#if defined (__USE_GNU) \|\| defined (__USE_MISC)
	125	#define __USE_REENTRANT 1
	126	#endif
	127
28f540f4	128
487253ea RM	129	/* This macro indicates that the installed library is the GNU C Library.
	130	Its value must be incremented whenever any existing library interface
	131	changes such that callers must be recompiled with the new header files.
	132	This value should always coincide with the major version number used for
	133	the shared C library corresponding to this set of header files. */
	134
28f540f4	135	#undef __GNU_LIBRARY__
487253ea	136	#define __GNU_LIBRARY__ 5
28f540f4 RM	137
	138
	139	#if !defined(__GNUC__) \|\| __GNUC__ < 2
	140	/* In GCC version 2, (__extension__ EXPR) will not complain
	141	about GCC extensions used in EXPR under -ansi or -pedantic. */
	142	#define __extension__
	143	#endif
	144
	145
	146	/* This is here only because every header file already includes this one. */
	147	#include <sys/cdefs.h>
	148
	149	/* This is here only because every header file already includes this one. */
	150	#ifndef _LIBC
	151	/* Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
	152	<stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
	153	which will always return failure (and set errno to ENOSYS).
	154
	155	We avoid including <stubs.h> when compiling the C library itself to
	156	avoid a dependency loop. stubs.h depends on every object file. If
	157	this #include were done for the library source code, then every object
	158	file would depend on stubs.h. */
	159
	160	#include <stubs.h>
	161	#endif
	162
	163	#endif /* __features.h */