[thirdparty/glibc.git] / include / features.h

/* Copyright (C) 1991-2017 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 Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#ifndef	_FEATURES_H
#define	_FEATURES_H	1

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

   __STRICT_ANSI__	ISO Standard C.
   _ISOC99_SOURCE	Extensions to ISO C89 from ISO C99.
   _ISOC11_SOURCE	Extensions to ISO C99 from ISO C11.
   __STDC_WANT_LIB_EXT2__
			Extensions to ISO C99 from TR 27431-2:2010.
   __STDC_WANT_IEC_60559_BFP_EXT__
			Extensions to ISO C11 from TS 18661-1:2014.
   __STDC_WANT_IEC_60559_FUNCS_EXT__
			Extensions to ISO C11 from TS 18661-4:2015.
   __STDC_WANT_IEC_60559_TYPES_EXT__
			Extensions to ISO C11 from TS 18661-3:2015.

   _POSIX_SOURCE	IEEE Std 1003.1.
   _POSIX_C_SOURCE	If ==1, like _POSIX_SOURCE; if >=2 add IEEE Std 1003.2;
			if >=199309L, add IEEE Std 1003.1b-1993;
			if >=199506L, add IEEE Std 1003.1c-1995;
			if >=200112L, all of IEEE 1003.1-2004
			if >=200809L, all of IEEE 1003.1-2008
   _XOPEN_SOURCE	Includes POSIX and XPG things.  Set to 500 if
			Single Unix conformance is wanted, to 600 for the
			sixth revision, to 700 for the seventh revision.
   _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
   _LARGEFILE_SOURCE	Some more functions for correct standard I/O.
   _LARGEFILE64_SOURCE	Additional functionality from LFS for large files.
   _FILE_OFFSET_BITS=N	Select default filesystem interface.
   _ATFILE_SOURCE	Additional *at interfaces.
   _GNU_SOURCE		All of the above, plus GNU extensions.
   _DEFAULT_SOURCE	The default set of features (taking precedence over
			__STRICT_ANSI__).

   _FORTIFY_SOURCE	Add security hardening to many library functions.
			Set to 1 or 2; 2 performs stricter checks than 1.

   _REENTRANT, _THREAD_SAFE
			Obsolete; equivalent to _POSIX_C_SOURCE=199506L.

   The `-ansi' switch to the GNU C compiler, and standards conformance
   options such as `-std=c99', define __STRICT_ANSI__.  If none of
   these are defined, or if _DEFAULT_SOURCE is defined, the default is
   to have _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
   200809L, as well as enabling miscellaneous functions from BSD and
   SVID.  If more than one of these are defined, they accumulate.  For
   example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE together
   give you ISO 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:

   __GLIBC_USE (F)	Define things from feature set F.  This is defined
			to 1 or 0; the subsequent macros are either defined
			or undefined, and those tests should be moved to
			__GLIBC_USE.
   __USE_ISOC11		Define ISO C11 things.
   __USE_ISOC99		Define ISO C99 things.
   __USE_ISOC95		Define ISO C90 AMD1 (C95) things.
   __USE_POSIX		Define IEEE Std 1003.1 things.
   __USE_POSIX2		Define IEEE Std 1003.2 things.
   __USE_POSIX199309	Define IEEE Std 1003.1, and .1b things.
   __USE_POSIX199506	Define IEEE Std 1003.1, .1b, .1c and .1i things.
   __USE_XOPEN		Define XPG things.
   __USE_XOPEN_EXTENDED	Define X/Open Unix things.
   __USE_UNIX98		Define Single Unix V2 things.
   __USE_XOPEN2K        Define XPG6 things.
   __USE_XOPEN2KXSI     Define XPG6 XSI things.
   __USE_XOPEN2K8       Define XPG7 things.
   __USE_XOPEN2K8XSI    Define XPG7 XSI things.
   __USE_LARGEFILE	Define correct standard I/O things.
   __USE_LARGEFILE64	Define LFS things with separate names.
   __USE_FILE_OFFSET64	Define 64bit interface as default.
   __USE_MISC		Define things from 4.3BSD or System V Unix.
   __USE_ATFILE		Define *at interfaces and AT_* constants for them.
   __USE_GNU		Define GNU extensions.
   __USE_FORTIFY_LEVEL	Additional security measures used, according to level.

   The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
   defined by this file unconditionally.  `__GNU_LIBRARY__' is provided
   only for compatibility.  All new code should use the other symbols
   to test for features.

   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.

   ISO C feature test macros depend on the definition of the macro
   when an affected header is included, not when the first system
   header is included, and so they are handled in
   <bits/libc-header-start.h>, which does not have a multiple include
   guard.  Feature test macros that can be handled from the first
   system header included are handled here.  */


/* Undefine everything, so we get a clean slate.  */
#undef	__USE_ISOC11
#undef	__USE_ISOC99
#undef	__USE_ISOC95
#undef	__USE_ISOCXX11
#undef	__USE_POSIX
#undef	__USE_POSIX2
#undef	__USE_POSIX199309
#undef	__USE_POSIX199506
#undef	__USE_XOPEN
#undef	__USE_XOPEN_EXTENDED
#undef	__USE_UNIX98
#undef	__USE_XOPEN2K
#undef	__USE_XOPEN2KXSI
#undef	__USE_XOPEN2K8
#undef	__USE_XOPEN2K8XSI
#undef	__USE_LARGEFILE
#undef	__USE_LARGEFILE64
#undef	__USE_FILE_OFFSET64
#undef	__USE_MISC
#undef	__USE_ATFILE
#undef	__USE_GNU
#undef	__USE_FORTIFY_LEVEL
#undef	__KERNEL_STRICT_NAMES
#undef	__GLIBC_USE_DEPRECATED_GETS

/* Suppress kernel-name space pollution unless user expressedly asks
   for it.  */
#ifndef _LOOSE_KERNEL_NAMES
# define __KERNEL_STRICT_NAMES
#endif

/* Convenience macro to test the version of gcc.
   Use like this:
   #if __GNUC_PREREQ (2,8)
   ... code requiring gcc 2.8 or later ...
   #endif
   Note: only works for GCC 2.0 and later, because __GNUC_MINOR__ was
   added in 2.0.  */
#if defined __GNUC__ && defined __GNUC_MINOR__
# define __GNUC_PREREQ(maj, min) \
	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
#else
# define __GNUC_PREREQ(maj, min) 0
#endif

/* Similarly for clang.  Features added to GCC after version 4.2 may
   or may not also be available in clang, and clang's definitions of
   __GNUC(_MINOR)__ are fixed at 4 and 2 respectively.  Not all such
   features can be queried via __has_extension/__has_feature.  */
#if defined __clang_major__ && defined __clang_minor__
# define __glibc_clang_prereq(maj, min) \
  ((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))
#else
# define __glibc_clang_prereq(maj, min) 0
#endif

/* Whether to use feature set F.  */
#define __GLIBC_USE(F)	__GLIBC_USE_ ## F

/* _BSD_SOURCE and _SVID_SOURCE are deprecated aliases for
   _DEFAULT_SOURCE.  If _DEFAULT_SOURCE is present we do not
   issue a warning; the expectation is that the source is being
   transitioned to use the new macro.  */
#if (defined _BSD_SOURCE || defined _SVID_SOURCE) \
    && !defined _DEFAULT_SOURCE
# warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"
# undef  _DEFAULT_SOURCE
# define _DEFAULT_SOURCE	1
#endif

/* If _GNU_SOURCE was defined by the user, turn on all the other features.  */
#ifdef _GNU_SOURCE
# undef  _ISOC95_SOURCE
# define _ISOC95_SOURCE	1
# undef  _ISOC99_SOURCE
# define _ISOC99_SOURCE	1
# undef  _ISOC11_SOURCE
# define _ISOC11_SOURCE	1
# undef  _POSIX_SOURCE
# define _POSIX_SOURCE	1
# undef  _POSIX_C_SOURCE
# define _POSIX_C_SOURCE	200809L
# undef  _XOPEN_SOURCE
# define _XOPEN_SOURCE	700
# undef  _XOPEN_SOURCE_EXTENDED
# define _XOPEN_SOURCE_EXTENDED	1
# undef	 _LARGEFILE64_SOURCE
# define _LARGEFILE64_SOURCE	1
# undef  _DEFAULT_SOURCE
# define _DEFAULT_SOURCE	1
# undef  _ATFILE_SOURCE
# define _ATFILE_SOURCE	1
#endif

/* If nothing (other than _GNU_SOURCE and _DEFAULT_SOURCE) is defined,
   define _DEFAULT_SOURCE.  */
#if (defined _DEFAULT_SOURCE					\
     || (!defined __STRICT_ANSI__				\
	 && !defined _ISOC99_SOURCE				\
	 && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE	\
	 && !defined _XOPEN_SOURCE))
# undef  _DEFAULT_SOURCE
# define _DEFAULT_SOURCE	1
#endif

/* This is to enable the ISO C11 extension.  */
#if (defined _ISOC11_SOURCE \
     || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L))
# define __USE_ISOC11	1
#endif

/* This is to enable the ISO C99 extension.  */
#if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \
     || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
# define __USE_ISOC99	1
#endif

/* This is to enable the ISO C90 Amendment 1:1995 extension.  */
#if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \
     || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
# define __USE_ISOC95	1
#endif

/* This is to enable compatibility for ISO C++11.

   So far g++ does not provide a macro.  Check the temporary macro for
   now, too.  */
#if ((defined __cplusplus && __cplusplus >= 201103L)			      \
     || defined __GXX_EXPERIMENTAL_CXX0X__)
# define __USE_ISOCXX11	1
#endif

/* If none of the ANSI/POSIX macros are defined, or if _DEFAULT_SOURCE
   is defined, use POSIX.1-2008 (or another version depending on
   _XOPEN_SOURCE).  */
#ifdef _DEFAULT_SOURCE
# if !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE
#  define __USE_POSIX_IMPLICITLY	1
# endif
# undef  _POSIX_SOURCE
# define _POSIX_SOURCE	1
# undef  _POSIX_C_SOURCE
# define _POSIX_C_SOURCE	200809L
#endif

#if ((!defined __STRICT_ANSI__					\
      || (defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) >= 500))	\
     && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
# define _POSIX_SOURCE	1
# if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
#  define _POSIX_C_SOURCE	2
# elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
#  define _POSIX_C_SOURCE	199506L
# elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700
#  define _POSIX_C_SOURCE	200112L
# else
#  define _POSIX_C_SOURCE	200809L
# endif
# define __USE_POSIX_IMPLICITLY	1
#endif

/* Some C libraries once required _REENTRANT and/or _THREAD_SAFE to be
   defined in all multithreaded code.  GNU libc has not required this
   for many years.  We now treat them as compatibility synonyms for
   _POSIX_C_SOURCE=199506L, which is the earliest level of POSIX with
   comprehensive support for multithreaded code.  Using them never
   lowers the selected level of POSIX conformance, only raises it.  */
#if ((!defined _POSIX_C_SOURCE || (_POSIX_C_SOURCE - 0) < 199506L) \
     && (defined _REENTRANT || defined _THREAD_SAFE))
# define _POSIX_SOURCE   1
# undef  _POSIX_C_SOURCE
# define _POSIX_C_SOURCE 199506L
#endif

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

#if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
# define __USE_POSIX2	1
#endif

#if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 199309L
# define __USE_POSIX199309	1
#endif

#if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 199506L
# define __USE_POSIX199506	1
#endif

#if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 200112L
# define __USE_XOPEN2K		1
# undef __USE_ISOC95
# define __USE_ISOC95		1
# undef __USE_ISOC99
# define __USE_ISOC99		1
#endif

#if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 200809L
# define __USE_XOPEN2K8		1
# undef  _ATFILE_SOURCE
# define _ATFILE_SOURCE	1
#endif

#ifdef	_XOPEN_SOURCE
# define __USE_XOPEN	1
# if (_XOPEN_SOURCE - 0) >= 500
#  define __USE_XOPEN_EXTENDED	1
#  define __USE_UNIX98	1
#  undef _LARGEFILE_SOURCE
#  define _LARGEFILE_SOURCE	1
#  if (_XOPEN_SOURCE - 0) >= 600
#   if (_XOPEN_SOURCE - 0) >= 700
#    define __USE_XOPEN2K8	1
#    define __USE_XOPEN2K8XSI	1
#   endif
#   define __USE_XOPEN2K	1
#   define __USE_XOPEN2KXSI	1
#   undef __USE_ISOC95
#   define __USE_ISOC95		1
#   undef __USE_ISOC99
#   define __USE_ISOC99		1
#  endif
# else
#  ifdef _XOPEN_SOURCE_EXTENDED
#   define __USE_XOPEN_EXTENDED	1
#  endif
# endif
#endif

#ifdef _LARGEFILE_SOURCE
# define __USE_LARGEFILE	1
#endif

#ifdef _LARGEFILE64_SOURCE
# define __USE_LARGEFILE64	1
#endif

#if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
# define __USE_FILE_OFFSET64	1
#endif

#if defined _DEFAULT_SOURCE
# define __USE_MISC	1
#endif

#ifdef	_ATFILE_SOURCE
# define __USE_ATFILE	1
#endif

#ifdef	_GNU_SOURCE
# define __USE_GNU	1
#endif

#if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0
# if !defined __OPTIMIZE__ || __OPTIMIZE__ <= 0
#  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
# elif !__GNUC_PREREQ (4, 1)
#  warning _FORTIFY_SOURCE requires GCC 4.1 or later
# elif _FORTIFY_SOURCE > 1
#  define __USE_FORTIFY_LEVEL 2
# else
#  define __USE_FORTIFY_LEVEL 1
# endif
#endif
#ifndef __USE_FORTIFY_LEVEL
# define __USE_FORTIFY_LEVEL 0
#endif

/* The function 'gets' existed in C89, but is impossible to use
   safely.  It has been removed from ISO C11 and ISO C++14.  Note: for
   compatibility with various implementations of <cstdio>, this test
   must consider only the value of __cplusplus when compiling C++.  */
#if defined __cplusplus ? __cplusplus >= 201402L : defined __USE_ISOC11
# define __GLIBC_USE_DEPRECATED_GETS 0
#else
# define __GLIBC_USE_DEPRECATED_GETS 1
#endif

/* Get definitions of __STDC_* predefined macros, if the compiler has
   not preincluded this header automatically.  */
#include <stdc-predef.h>

/* This macro indicates that the installed library is the GNU C Library.
   For historic reasons the value now is 6 and this will stay from now
   on.  The use of this variable is deprecated.  Use __GLIBC__ and
   __GLIBC_MINOR__ now (see below) when you want to test for a specific
   GNU C library version and use the values in <gnu/lib-names.h> to get
   the sonames of the shared libraries.  */
#undef  __GNU_LIBRARY__
#define __GNU_LIBRARY__ 6

/* Major and minor version number of the GNU C library package.  Use
   these macros to test for features in specific releases.  */
#define	__GLIBC__	2
#define	__GLIBC_MINOR__	25

#define __GLIBC_PREREQ(maj, min) \
	((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))

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

/* If we don't have __REDIRECT, prototypes will be missing if
   __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
# if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
#  define __USE_LARGEFILE	1
#  define __USE_LARGEFILE64	1
# endif

#endif	/* !ASSEMBLER */

/* Decide whether we can define 'extern inline' functions in headers.  */
#if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
    && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
    && defined __extern_inline
# define __USE_EXTERN_INLINES	1
#endif


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


#endif	/* features.h  */
Commit	Line	Data
bfff8b1b	1	/* Copyright (C) 1991-2017 Free Software Foundation, Inc.
2c6fe0bd	2	This file is part of the GNU C Library.
28f540f4	3
2c6fe0bd	4	The GNU C Library is free software; you can redistribute it and/or
41bdb6e2 AJ	5	modify it under the terms of the GNU Lesser General Public
	6	License as published by the Free Software Foundation; either
	7	version 2.1 of the License, or (at your option) any later version.
28f540f4	8
2c6fe0bd UD	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
41bdb6e2	12	Lesser General Public License for more details.
28f540f4	13
41bdb6e2	14	You should have received a copy of the GNU Lesser General Public
59ba27a6 PE	15	License along with the GNU C Library; if not, see
59ba27a6 PE	16	<http://www.gnu.org/licenses/>. */
28f540f4 RM	17
28f540f4 RM	18	#ifndef _FEATURES_H
28f540f4 RM	19	#define _FEATURES_H 1
	20
	21	/* These are defined by the user (or the compiler)
	22	to specify the desired environment:
	23
d38cd08c	24	__STRICT_ANSI__ ISO Standard C.
ec751a23	25	_ISOC99_SOURCE Extensions to ISO C89 from ISO C99.
d7809905	26	_ISOC11_SOURCE Extensions to ISO C99 from ISO C11.
c0307377 ZW	27	__STDC_WANT_LIB_EXT2__
	28	Extensions to ISO C99 from TR 27431-2:2010.
	29	__STDC_WANT_IEC_60559_BFP_EXT__
	30	Extensions to ISO C11 from TS 18661-1:2014.
	31	__STDC_WANT_IEC_60559_FUNCS_EXT__
	32	Extensions to ISO C11 from TS 18661-4:2015.
4fc12f0e PM	33	__STDC_WANT_IEC_60559_TYPES_EXT__
4fc12f0e PM	34	Extensions to ISO C11 from TS 18661-3:2015.
c0307377	35
28f540f4	36	_POSIX_SOURCE IEEE Std 1003.1.
6d52618b	37	_POSIX_C_SOURCE If ==1, like _POSIX_SOURCE; if >=2 add IEEE Std 1003.2;
118bad87	38	if >=199309L, add IEEE Std 1003.1b-1993;
7a80496f UD	39	if >=199506L, add IEEE Std 1003.1c-1995;
7a80496f UD	40	if >=200112L, all of IEEE 1003.1-2004
3e6b0a28	41	if >=200809L, all of IEEE 1003.1-2008
a5a0310d	42	_XOPEN_SOURCE Includes POSIX and XPG things. Set to 500 if
925e31d9	43	Single Unix conformance is wanted, to 600 for the
3e6b0a28	44	sixth revision, to 700 for the seventh revision.
2c6fe0bd	45	_XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
dfd2257a UD	46	_LARGEFILE_SOURCE Some more functions for correct standard I/O.
	47	_LARGEFILE64_SOURCE Additional functionality from LFS for large files.
	48	_FILE_OFFSET_BITS=N Select default filesystem interface.
0b8f25bb	49	_ATFILE_SOURCE Additional *at interfaces.
28f540f4	50	_GNU_SOURCE All of the above, plus GNU extensions.
c688b419 JM	51	_DEFAULT_SOURCE The default set of features (taking precedence over
c688b419 JM	52	__STRICT_ANSI__).
c0307377 ZW	53
	54	_FORTIFY_SOURCE Add security hardening to many library functions.
	55	Set to 1 or 2; 2 performs stricter checks than 1.
	56
	57	_REENTRANT, _THREAD_SAFE
	58	Obsolete; equivalent to _POSIX_C_SOURCE=199506L.
28f540f4	59
c688b419 JM	60	The `-ansi' switch to the GNU C compiler, and standards conformance
	61	options such as `-std=c99', define __STRICT_ANSI__. If none of
	62	these are defined, or if _DEFAULT_SOURCE is defined, the default is
c941736c JM	63	to have _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
	64	200809L, as well as enabling miscellaneous functions from BSD and
	65	SVID. If more than one of these are defined, they accumulate. For
	66	example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE together
	67	give you ISO C, 1003.1, and 1003.2, but nothing else.
28f540f4 RM	68
	69	These are defined by this file and are used by the
	70	header files to decide what to declare or define:
	71
48789000 JM	72	__GLIBC_USE (F) Define things from feature set F. This is defined
	73	to 1 or 0; the subsequent macros are either defined
	74	or undefined, and those tests should be moved to
	75	__GLIBC_USE.
d7809905	76	__USE_ISOC11 Define ISO C11 things.
ec751a23	77	__USE_ISOC99 Define ISO C99 things.
087722b8	78	__USE_ISOC95 Define ISO C90 AMD1 (C95) things.
28f540f4 RM	79	__USE_POSIX Define IEEE Std 1003.1 things.
28f540f4 RM	80	__USE_POSIX2 Define IEEE Std 1003.2 things.
4a582094 UD	81	__USE_POSIX199309 Define IEEE Std 1003.1, and .1b things.
4a582094 UD	82	__USE_POSIX199506 Define IEEE Std 1003.1, .1b, .1c and .1i things.
2c6fe0bd UD	83	__USE_XOPEN Define XPG things.
2c6fe0bd UD	84	__USE_XOPEN_EXTENDED Define X/Open Unix things.
a5a0310d	85	__USE_UNIX98 Define Single Unix V2 things.
925e31d9	86	__USE_XOPEN2K Define XPG6 things.
f095bb72	87	__USE_XOPEN2KXSI Define XPG6 XSI things.
81489b2e	88	__USE_XOPEN2K8 Define XPG7 things.
f095bb72	89	__USE_XOPEN2K8XSI Define XPG7 XSI things.
925e31d9	90	__USE_LARGEFILE Define correct standard I/O things.
dfd2257a UD	91	__USE_LARGEFILE64 Define LFS things with separate names.
dfd2257a UD	92	__USE_FILE_OFFSET64 Define 64bit interface as default.
498afc54	93	__USE_MISC Define things from 4.3BSD or System V Unix.
0b8f25bb	94	__USE_ATFILE Define at interfaces and AT_ constants for them.
28f540f4	95	__USE_GNU Define GNU extensions.
b5cc329c	96	__USE_FORTIFY_LEVEL Additional security measures used, according to level.
28f540f4	97
d38cd08c UD	98	The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
	99	defined by this file unconditionally. `__GNU_LIBRARY__' is provided
	100	only for compatibility. All new code should use the other symbols
	101	to test for features.
28f540f4	102
28f540f4 RM	103	All macros listed above as possibly being defined by this file are
	104	explicitly undefined if they are not explicitly defined.
	105	Feature-test macros that are not defined by the user or compiler
	106	but are implied by the other feature-test macros defined (or by the
48789000 JM	107	lack of any definitions) are defined by the file.
	108
	109	ISO C feature test macros depend on the definition of the macro
	110	when an affected header is included, not when the first system
	111	header is included, and so they are handled in
	112	<bits/libc-header-start.h>, which does not have a multiple include
	113	guard. Feature test macros that can be handled from the first
	114	system header included are handled here. */
28f540f4 RM	115
	116
	117	/* Undefine everything, so we get a clean slate. */
d7809905	118	#undef __USE_ISOC11
ec751a23	119	#undef __USE_ISOC99
087722b8	120	#undef __USE_ISOC95
8fd8ff3b	121	#undef __USE_ISOCXX11
28f540f4 RM	122	#undef __USE_POSIX
28f540f4 RM	123	#undef __USE_POSIX2
6d52618b	124	#undef __USE_POSIX199309
4a582094	125	#undef __USE_POSIX199506
2c6fe0bd UD	126	#undef __USE_XOPEN
2c6fe0bd UD	127	#undef __USE_XOPEN_EXTENDED
dfd2257a	128	#undef __USE_UNIX98
24d6fe58	129	#undef __USE_XOPEN2K
f095bb72	130	#undef __USE_XOPEN2KXSI
3e6b0a28	131	#undef __USE_XOPEN2K8
f095bb72	132	#undef __USE_XOPEN2K8XSI
dfd2257a UD	133	#undef __USE_LARGEFILE
	134	#undef __USE_LARGEFILE64
	135	#undef __USE_FILE_OFFSET64
28f540f4	136	#undef __USE_MISC
0b8f25bb	137	#undef __USE_ATFILE
28f540f4	138	#undef __USE_GNU
b5cc329c	139	#undef __USE_FORTIFY_LEVEL
a1470b6f	140	#undef __KERNEL_STRICT_NAMES
7caa5054	141	#undef __GLIBC_USE_DEPRECATED_GETS
28f540f4	142
a1470b6f	143	/* Suppress kernel-name space pollution unless user expressedly asks
2c6fe0bd	144	for it. */
a1470b6f RM	145	#ifndef _LOOSE_KERNEL_NAMES
	146	# define __KERNEL_STRICT_NAMES
	147	#endif
28f540f4	148
cab4d74b ZW	149	/* Convenience macro to test the version of gcc.
cab4d74b ZW	150	Use like this:
b5cc329c UD	151	#if __GNUC_PREREQ (2,8)
	152	... code requiring gcc 2.8 or later ...
	153	#endif
cab4d74b ZW	154	Note: only works for GCC 2.0 and later, because __GNUC_MINOR__ was
cab4d74b ZW	155	added in 2.0. */
b5cc329c UD	156	#if defined __GNUC__ && defined __GNUC_MINOR__
	157	# define __GNUC_PREREQ(maj, min) \
	158	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
	159	#else
	160	# define __GNUC_PREREQ(maj, min) 0
	161	#endif
	162
cab4d74b ZW	163	/* Similarly for clang. Features added to GCC after version 4.2 may
	164	or may not also be available in clang, and clang's definitions of
	165	__GNUC(_MINOR)__ are fixed at 4 and 2 respectively. Not all such
	166	features can be queried via __has_extension/__has_feature. */
	167	#if defined __clang_major__ && defined __clang_minor__
	168	# define __glibc_clang_prereq(maj, min) \
	169	((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))
	170	#else
	171	# define __glibc_clang_prereq(maj, min) 0
	172	#endif
	173
48789000 JM	174	/* Whether to use feature set F. */
	175	#define __GLIBC_USE(F) __GLIBC_USE_ ## F
	176
c941736c	177	/* _BSD_SOURCE and _SVID_SOURCE are deprecated aliases for
ade40b10 CD	178	_DEFAULT_SOURCE. If _DEFAULT_SOURCE is present we do not
	179	issue a warning; the expectation is that the source is being
	180	transitioned to use the new macro. */
	181	#if (defined _BSD_SOURCE \|\| defined _SVID_SOURCE) \
	182	&& !defined _DEFAULT_SOURCE
c941736c JM	183	# warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"
	184	# undef _DEFAULT_SOURCE
	185	# define _DEFAULT_SOURCE 1
	186	#endif
28f540f4	187
59dd8641 RM	188	/* If _GNU_SOURCE was defined by the user, turn on all the other features. */
59dd8641 RM	189	#ifdef _GNU_SOURCE
e531ede5 UD	190	# undef _ISOC95_SOURCE
e531ede5 UD	191	# define _ISOC95_SOURCE 1
ec751a23 UD	192	# undef _ISOC99_SOURCE
ec751a23 UD	193	# define _ISOC99_SOURCE 1
d7809905 UD	194	# undef _ISOC11_SOURCE
d7809905 UD	195	# define _ISOC11_SOURCE 1
5107cf1d UD	196	# undef _POSIX_SOURCE
	197	# define _POSIX_SOURCE 1
	198	# undef _POSIX_C_SOURCE
3e6b0a28	199	# define _POSIX_C_SOURCE 200809L
5107cf1d	200	# undef _XOPEN_SOURCE
3e6b0a28	201	# define _XOPEN_SOURCE 700
5107cf1d UD	202	# undef _XOPEN_SOURCE_EXTENDED
5107cf1d UD	203	# define _XOPEN_SOURCE_EXTENDED 1
dfd2257a UD	204	# undef _LARGEFILE64_SOURCE
dfd2257a UD	205	# define _LARGEFILE64_SOURCE 1
c688b419 JM	206	# undef _DEFAULT_SOURCE
c688b419 JM	207	# define _DEFAULT_SOURCE 1
0b8f25bb RM	208	# undef _ATFILE_SOURCE
0b8f25bb RM	209	# define _ATFILE_SOURCE 1
59dd8641	210	#endif
28f540f4	211
c688b419	212	/* If nothing (other than _GNU_SOURCE and _DEFAULT_SOURCE) is defined,
498afc54	213	define _DEFAULT_SOURCE. */
c688b419 JM	214	#if (defined _DEFAULT_SOURCE \
	215	\|\| (!defined __STRICT_ANSI__ \
	216	&& !defined _ISOC99_SOURCE \
	217	&& !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE \
498afc54	218	&& !defined _XOPEN_SOURCE))
c688b419 JM	219	# undef _DEFAULT_SOURCE
c688b419 JM	220	# define _DEFAULT_SOURCE 1
28f540f4 RM	221	#endif
28f540f4 RM	222
d7809905 UD	223	/* This is to enable the ISO C11 extension. */
	224	#if (defined _ISOC11_SOURCE \
	225	\|\| (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L))
c0e87cc0 UD	226	# define __USE_ISOC11 1
c0e87cc0 UD	227	#endif
d7809905 UD	228
	229	/* This is to enable the ISO C99 extension. */
	230	#if (defined _ISOC99_SOURCE \|\| defined _ISOC11_SOURCE \
47a81620	231	\|\| (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
ec751a23	232	# define __USE_ISOC99 1
2f6d1f1b UD	233	#endif
2f6d1f1b UD	234
087722b8	235	/* This is to enable the ISO C90 Amendment 1:1995 extension. */
d7809905	236	#if (defined _ISOC99_SOURCE \|\| defined _ISOC11_SOURCE \
087722b8 UD	237	\|\| (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
	238	# define __USE_ISOC95 1
	239	#endif
	240
8fd8ff3b UD	241	/* This is to enable compatibility for ISO C++11.
	242
	243	So far g++ does not provide a macro. Check the temporary macro for
	244	now, too. */
	245	#if ((defined __cplusplus && __cplusplus >= 201103L) \
	246	\|\| defined __GXX_EXPERIMENTAL_CXX0X__)
	247	# define __USE_ISOCXX11 1
	248	#endif
	249
c688b419 JM	250	/* If none of the ANSI/POSIX macros are defined, or if _DEFAULT_SOURCE
	251	is defined, use POSIX.1-2008 (or another version depending on
	252	_XOPEN_SOURCE). */
	253	#ifdef _DEFAULT_SOURCE
	254	# if !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE
	255	# define __USE_POSIX_IMPLICITLY 1
	256	# endif
	257	# undef _POSIX_SOURCE
	258	# define _POSIX_SOURCE 1
	259	# undef _POSIX_C_SOURCE
	260	# define _POSIX_C_SOURCE 200809L
	261	#endif
c0307377	262
f248238c JM	263	#if ((!defined __STRICT_ANSI__ \
	264	\|\| (defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) >= 500)) \
	265	&& !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
5107cf1d	266	# define _POSIX_SOURCE 1
925e31d9	267	# if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
5107cf1d	268	# define _POSIX_C_SOURCE 2
1676aaef	269	# elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
a334319f	270	# define _POSIX_C_SOURCE 199506L
3e6b0a28	271	# elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700
1676aaef	272	# define _POSIX_C_SOURCE 200112L
3e6b0a28 UD	273	# else
3e6b0a28 UD	274	# define _POSIX_C_SOURCE 200809L
5107cf1d	275	# endif
2e6d6bac	276	# define __USE_POSIX_IMPLICITLY 1
28f540f4 RM	277	#endif
28f540f4 RM	278
c0307377 ZW	279	/* Some C libraries once required _REENTRANT and/or _THREAD_SAFE to be
	280	defined in all multithreaded code. GNU libc has not required this
	281	for many years. We now treat them as compatibility synonyms for
	282	_POSIX_C_SOURCE=199506L, which is the earliest level of POSIX with
	283	comprehensive support for multithreaded code. Using them never
	284	lowers the selected level of POSIX conformance, only raises it. */
	285	#if ((!defined _POSIX_C_SOURCE \|\| (_POSIX_C_SOURCE - 0) < 199506L) \
	286	&& (defined _REENTRANT \|\| defined _THREAD_SAFE))
	287	# define _POSIX_SOURCE 1
	288	# undef _POSIX_C_SOURCE
	289	# define _POSIX_C_SOURCE 199506L
	290	#endif
	291
f248238c JM	292	#if (defined _POSIX_SOURCE \
	293	\|\| (defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 1) \
	294	\|\| defined _XOPEN_SOURCE)
5107cf1d	295	# define __USE_POSIX 1
28f540f4 RM	296	#endif
28f540f4 RM	297
d38cd08c	298	#if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 \|\| defined _XOPEN_SOURCE
5107cf1d	299	# define __USE_POSIX2 1
28f540f4 RM	300	#endif
28f540f4 RM	301
f248238c	302	#if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 199309L
9756dfe1	303	# define __USE_POSIX199309 1
6d52618b UD	304	#endif
6d52618b UD	305
f248238c	306	#if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 199506L
4a582094 UD	307	# define __USE_POSIX199506 1
	308	#endif
	309
f248238c	310	#if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 200112L
23ae6451	311	# define __USE_XOPEN2K 1
e531ede5 UD	312	# undef __USE_ISOC95
e531ede5 UD	313	# define __USE_ISOC95 1
c163ee23 UD	314	# undef __USE_ISOC99
c163ee23 UD	315	# define __USE_ISOC99 1
23ae6451 UD	316	#endif
23ae6451 UD	317
f248238c	318	#if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 200809L
3e6b0a28 UD	319	# define __USE_XOPEN2K8 1
	320	# undef _ATFILE_SOURCE
	321	# define _ATFILE_SOURCE 1
	322	#endif
	323
2c6fe0bd	324	#ifdef _XOPEN_SOURCE
5107cf1d	325	# define __USE_XOPEN 1
219aa9e9	326	# if (_XOPEN_SOURCE - 0) >= 500
5107cf1d	327	# define __USE_XOPEN_EXTENDED 1
a5a0310d	328	# define __USE_UNIX98 1
dfd2257a UD	329	# undef _LARGEFILE_SOURCE
dfd2257a UD	330	# define _LARGEFILE_SOURCE 1
925e31d9	331	# if (_XOPEN_SOURCE - 0) >= 600
3e6b0a28 UD	332	# if (_XOPEN_SOURCE - 0) >= 700
3e6b0a28 UD	333	# define __USE_XOPEN2K8 1
f095bb72	334	# define __USE_XOPEN2K8XSI 1
3e6b0a28	335	# endif
219aa9e9	336	# define __USE_XOPEN2K 1
f095bb72	337	# define __USE_XOPEN2KXSI 1
e531ede5 UD	338	# undef __USE_ISOC95
e531ede5 UD	339	# define __USE_ISOC95 1
91bc38d0 UD	340	# undef __USE_ISOC99
91bc38d0 UD	341	# define __USE_ISOC99 1
219aa9e9	342	# endif
a5a0310d UD	343	# else
	344	# ifdef _XOPEN_SOURCE_EXTENDED
	345	# define __USE_XOPEN_EXTENDED 1
	346	# endif
5107cf1d	347	# endif
2c6fe0bd UD	348	#endif
2c6fe0bd UD	349
dfd2257a UD	350	#ifdef _LARGEFILE_SOURCE
	351	# define __USE_LARGEFILE 1
	352	#endif
	353
	354	#ifdef _LARGEFILE64_SOURCE
	355	# define __USE_LARGEFILE64 1
	356	#endif
	357
	358	#if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
	359	# define __USE_FILE_OFFSET64 1
	360	#endif
	361
498afc54	362	#if defined _DEFAULT_SOURCE
5107cf1d	363	# define __USE_MISC 1
28f540f4 RM	364	#endif
28f540f4 RM	365
0b8f25bb RM	366	#ifdef _ATFILE_SOURCE
	367	# define __USE_ATFILE 1
	368	#endif
	369
28f540f4	370	#ifdef _GNU_SOURCE
5107cf1d	371	# define __USE_GNU 1
28f540f4 RM	372	#endif
28f540f4 RM	373
05c2c961 RMG	374	#if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0
	375	# if !defined __OPTIMIZE__ \|\| __OPTIMIZE__ <= 0
	376	# warning _FORTIFY_SOURCE requires compiling with optimization (-O)
	377	# elif !__GNUC_PREREQ (4, 1)
	378	# warning _FORTIFY_SOURCE requires GCC 4.1 or later
	379	# elif _FORTIFY_SOURCE > 1
a334319f	380	# define __USE_FORTIFY_LEVEL 2
faa26ad4 RM	381	# else
faa26ad4 RM	382	# define __USE_FORTIFY_LEVEL 1
b5cc329c	383	# endif
05c2c961 RMG	384	#endif
05c2c961 RMG	385	#ifndef __USE_FORTIFY_LEVEL
faa26ad4	386	# define __USE_FORTIFY_LEVEL 0
b5cc329c UD	387	#endif
b5cc329c UD	388
7caa5054 ZW	389	/* The function 'gets' existed in C89, but is impossible to use
	390	safely. It has been removed from ISO C11 and ISO C++14. Note: for
	391	compatibility with various implementations of <cstdio>, this test
	392	must consider only the value of __cplusplus when compiling C++. */
	393	#if defined __cplusplus ? __cplusplus >= 201402L : defined __USE_ISOC11
	394	# define __GLIBC_USE_DEPRECATED_GETS 0
	395	#else
	396	# define __GLIBC_USE_DEPRECATED_GETS 1
	397	#endif
	398
ff3b3d82 JM	399	/* Get definitions of __STDC_* predefined macros, if the compiler has
	400	not preincluded this header automatically. */
	401	#include <stdc-predef.h>
91bc38d0	402
ba1ffaa1 UD	403	/* This macro indicates that the installed library is the GNU C Library.
	404	For historic reasons the value now is 6 and this will stay from now
	405	on. The use of this variable is deprecated. Use __GLIBC__ and
	406	__GLIBC_MINOR__ now (see below) when you want to test for a specific
	407	GNU C library version and use the values in <gnu/lib-names.h> to get
	408	the sonames of the shared libraries. */
	409	#undef __GNU_LIBRARY__
	410	#define __GNU_LIBRARY__ 6
	411
	412	/* Major and minor version number of the GNU C library package. Use
	413	these macros to test for features in specific releases. */
	414	#define __GLIBC__ 2
db0242e3	415	#define __GLIBC_MINOR__ 25
28f540f4	416
f042f18f UD	417	#define __GLIBC_PREREQ(maj, min) \
f042f18f UD	418	((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
4360eafd	419
28f540f4	420	/* This is here only because every header file already includes this one. */
edf5b2d7	421	#ifndef __ASSEMBLER__
95589177 UD	422	# ifndef _SYS_CDEFS_H
	423	# include <sys/cdefs.h>
	424	# endif
01cad722 UD	425
	426	/* If we don't have __REDIRECT, prototypes will be missing if
	427	__USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
	428	# if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
4152ed15 UD	429	# define __USE_LARGEFILE 1
4152ed15 UD	430	# define __USE_LARGEFILE64 1
01cad722 UD	431	# endif
01cad722 UD	432
eedbbe58 UD	433	#endif /* !ASSEMBLER */
	434
	435	/* Decide whether we can define 'extern inline' functions in headers. */
07c416ed	436	#if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
de1c3ebb UD	437	&& !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
de1c3ebb UD	438	&& defined __extern_inline
eedbbe58	439	# define __USE_EXTERN_INLINES 1
edf5b2d7	440	#endif
28f540f4	441
28f540f4	442
ce460d04 RM	443	/* This is here only because every header file already includes this one.
	444	Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
	445	<gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
	446	that will always return failure (and set errno to ENOSYS). */
	447	#include <gnu/stubs.h>
28f540f4	448
28f540f4	449
6ed0492f	450	#endif /* features.h */