glibc (2.38)

(root)/
include/
features.h
       1  /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
       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 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.
       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     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #ifndef	_FEATURES_H
      19  #define	_FEATURES_H	1
      20  
      21  /* These are defined by the user (or the compiler)
      22     to specify the desired environment:
      23  
      24     __STRICT_ANSI__	ISO Standard C.
      25     _ISOC99_SOURCE	Extensions to ISO C89 from ISO C99.
      26     _ISOC11_SOURCE	Extensions to ISO C99 from ISO C11.
      27     _ISOC2X_SOURCE	Extensions to ISO C99 from ISO C2X.
      28     __STDC_WANT_LIB_EXT2__
      29  			Extensions to ISO C99 from TR 27431-2:2010.
      30     __STDC_WANT_IEC_60559_BFP_EXT__
      31  			Extensions to ISO C11 from TS 18661-1:2014.
      32     __STDC_WANT_IEC_60559_FUNCS_EXT__
      33  			Extensions to ISO C11 from TS 18661-4:2015.
      34     __STDC_WANT_IEC_60559_TYPES_EXT__
      35  			Extensions to ISO C11 from TS 18661-3:2015.
      36     __STDC_WANT_IEC_60559_EXT__
      37  			ISO C2X interfaces defined only in Annex F.
      38  
      39     _POSIX_SOURCE	IEEE Std 1003.1.
      40     _POSIX_C_SOURCE	If ==1, like _POSIX_SOURCE; if >=2 add IEEE Std 1003.2;
      41  			if >=199309L, add IEEE Std 1003.1b-1993;
      42  			if >=199506L, add IEEE Std 1003.1c-1995;
      43  			if >=200112L, all of IEEE 1003.1-2004
      44  			if >=200809L, all of IEEE 1003.1-2008
      45     _XOPEN_SOURCE	Includes POSIX and XPG things.  Set to 500 if
      46  			Single Unix conformance is wanted, to 600 for the
      47  			sixth revision, to 700 for the seventh revision.
      48     _XOPEN_SOURCE_EXTENDED XPG things and X/Open Unix extensions.
      49     _LARGEFILE_SOURCE	Some more functions for correct standard I/O.
      50     _LARGEFILE64_SOURCE	Additional functionality from LFS for large files.
      51     _FILE_OFFSET_BITS=N	Select default filesystem interface.
      52     _ATFILE_SOURCE	Additional *at interfaces.
      53     _DYNAMIC_STACK_SIZE_SOURCE Select correct (but non compile-time constant)
      54  			MINSIGSTKSZ, SIGSTKSZ and PTHREAD_STACK_MIN.
      55     _GNU_SOURCE		All of the above, plus GNU extensions.
      56     _DEFAULT_SOURCE	The default set of features (taking precedence over
      57  			__STRICT_ANSI__).
      58  
      59     _FORTIFY_SOURCE	Add security hardening to many library functions.
      60  			Set to 1, 2 or 3; 3 performs stricter checks than 2, which
      61  			performs stricter checks than 1.
      62  
      63     _REENTRANT, _THREAD_SAFE
      64  			Obsolete; equivalent to _POSIX_C_SOURCE=199506L.
      65  
      66     The `-ansi' switch to the GNU C compiler, and standards conformance
      67     options such as `-std=c99', define __STRICT_ANSI__.  If none of
      68     these are defined, or if _DEFAULT_SOURCE is defined, the default is
      69     to have _POSIX_SOURCE set to one and _POSIX_C_SOURCE set to
      70     200809L, as well as enabling miscellaneous functions from BSD and
      71     SVID.  If more than one of these are defined, they accumulate.  For
      72     example __STRICT_ANSI__, _POSIX_SOURCE and _POSIX_C_SOURCE together
      73     give you ISO C, 1003.1, and 1003.2, but nothing else.
      74  
      75     These are defined by this file and are used by the
      76     header files to decide what to declare or define:
      77  
      78     __GLIBC_USE (F)	Define things from feature set F.  This is defined
      79  			to 1 or 0; the subsequent macros are either defined
      80  			or undefined, and those tests should be moved to
      81  			__GLIBC_USE.
      82     __USE_ISOC11		Define ISO C11 things.
      83     __USE_ISOC99		Define ISO C99 things.
      84     __USE_ISOC95		Define ISO C90 AMD1 (C95) things.
      85     __USE_ISOCXX11	Define ISO C++11 things.
      86     __USE_POSIX		Define IEEE Std 1003.1 things.
      87     __USE_POSIX2		Define IEEE Std 1003.2 things.
      88     __USE_POSIX199309	Define IEEE Std 1003.1, and .1b things.
      89     __USE_POSIX199506	Define IEEE Std 1003.1, .1b, .1c and .1i things.
      90     __USE_XOPEN		Define XPG things.
      91     __USE_XOPEN_EXTENDED	Define X/Open Unix things.
      92     __USE_UNIX98		Define Single Unix V2 things.
      93     __USE_XOPEN2K        Define XPG6 things.
      94     __USE_XOPEN2KXSI     Define XPG6 XSI things.
      95     __USE_XOPEN2K8       Define XPG7 things.
      96     __USE_XOPEN2K8XSI    Define XPG7 XSI things.
      97     __USE_LARGEFILE	Define correct standard I/O things.
      98     __USE_LARGEFILE64	Define LFS things with separate names.
      99     __USE_FILE_OFFSET64	Define 64bit interface as default.
     100     __USE_MISC		Define things from 4.3BSD or System V Unix.
     101     __USE_ATFILE		Define *at interfaces and AT_* constants for them.
     102     __USE_DYNAMIC_STACK_SIZE Define correct (but non compile-time constant)
     103  			MINSIGSTKSZ, SIGSTKSZ and PTHREAD_STACK_MIN.
     104     __USE_GNU		Define GNU extensions.
     105     __USE_FORTIFY_LEVEL	Additional security measures used, according to level.
     106  
     107     The macros `__GNU_LIBRARY__', `__GLIBC__', and `__GLIBC_MINOR__' are
     108     defined by this file unconditionally.  `__GNU_LIBRARY__' is provided
     109     only for compatibility.  All new code should use the other symbols
     110     to test for features.
     111  
     112     All macros listed above as possibly being defined by this file are
     113     explicitly undefined if they are not explicitly defined.
     114     Feature-test macros that are not defined by the user or compiler
     115     but are implied by the other feature-test macros defined (or by the
     116     lack of any definitions) are defined by the file.
     117  
     118     ISO C feature test macros depend on the definition of the macro
     119     when an affected header is included, not when the first system
     120     header is included, and so they are handled in
     121     <bits/libc-header-start.h>, which does not have a multiple include
     122     guard.  Feature test macros that can be handled from the first
     123     system header included are handled here.  */
     124  
     125  
     126  /* Undefine everything, so we get a clean slate.  */
     127  #undef	__USE_ISOC11
     128  #undef	__USE_ISOC99
     129  #undef	__USE_ISOC95
     130  #undef	__USE_ISOCXX11
     131  #undef	__USE_POSIX
     132  #undef	__USE_POSIX2
     133  #undef	__USE_POSIX199309
     134  #undef	__USE_POSIX199506
     135  #undef	__USE_XOPEN
     136  #undef	__USE_XOPEN_EXTENDED
     137  #undef	__USE_UNIX98
     138  #undef	__USE_XOPEN2K
     139  #undef	__USE_XOPEN2KXSI
     140  #undef	__USE_XOPEN2K8
     141  #undef	__USE_XOPEN2K8XSI
     142  #undef	__USE_LARGEFILE
     143  #undef	__USE_LARGEFILE64
     144  #undef	__USE_FILE_OFFSET64
     145  #undef	__USE_MISC
     146  #undef	__USE_ATFILE
     147  #undef	__USE_DYNAMIC_STACK_SIZE
     148  #undef	__USE_GNU
     149  #undef	__USE_FORTIFY_LEVEL
     150  #undef	__KERNEL_STRICT_NAMES
     151  #undef	__GLIBC_USE_ISOC2X
     152  #undef	__GLIBC_USE_DEPRECATED_GETS
     153  #undef	__GLIBC_USE_DEPRECATED_SCANF
     154  #undef	__GLIBC_USE_C2X_STRTOL
     155  
     156  /* Suppress kernel-name space pollution unless user expressedly asks
     157     for it.  */
     158  #ifndef _LOOSE_KERNEL_NAMES
     159  # define __KERNEL_STRICT_NAMES
     160  #endif
     161  
     162  /* Convenience macro to test the version of gcc.
     163     Use like this:
     164     #if __GNUC_PREREQ (2,8)
     165     ... code requiring gcc 2.8 or later ...
     166     #endif
     167     Note: only works for GCC 2.0 and later, because __GNUC_MINOR__ was
     168     added in 2.0.  */
     169  #if defined __GNUC__ && defined __GNUC_MINOR__
     170  # define __GNUC_PREREQ(maj, min) \
     171  	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
     172  #else
     173  # define __GNUC_PREREQ(maj, min) 0
     174  #endif
     175  
     176  /* Similarly for clang.  Features added to GCC after version 4.2 may
     177     or may not also be available in clang, and clang's definitions of
     178     __GNUC(_MINOR)__ are fixed at 4 and 2 respectively.  Not all such
     179     features can be queried via __has_extension/__has_feature.  */
     180  #if defined __clang_major__ && defined __clang_minor__
     181  # define __glibc_clang_prereq(maj, min) \
     182    ((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))
     183  #else
     184  # define __glibc_clang_prereq(maj, min) 0
     185  #endif
     186  
     187  /* Whether to use feature set F.  */
     188  #define __GLIBC_USE(F)	__GLIBC_USE_ ## F
     189  
     190  /* _BSD_SOURCE and _SVID_SOURCE are deprecated aliases for
     191     _DEFAULT_SOURCE.  If _DEFAULT_SOURCE is present we do not
     192     issue a warning; the expectation is that the source is being
     193     transitioned to use the new macro.  */
     194  #if (defined _BSD_SOURCE || defined _SVID_SOURCE) \
     195      && !defined _DEFAULT_SOURCE
     196  # warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"
     197  # undef  _DEFAULT_SOURCE
     198  # define _DEFAULT_SOURCE	1
     199  #endif
     200  
     201  /* If _GNU_SOURCE was defined by the user, turn on all the other features.  */
     202  #ifdef _GNU_SOURCE
     203  # undef  _ISOC95_SOURCE
     204  # define _ISOC95_SOURCE	1
     205  # undef  _ISOC99_SOURCE
     206  # define _ISOC99_SOURCE	1
     207  # undef  _ISOC11_SOURCE
     208  # define _ISOC11_SOURCE	1
     209  # undef  _ISOC2X_SOURCE
     210  # define _ISOC2X_SOURCE	1
     211  # undef  _POSIX_SOURCE
     212  # define _POSIX_SOURCE	1
     213  # undef  _POSIX_C_SOURCE
     214  # define _POSIX_C_SOURCE	200809L
     215  # undef  _XOPEN_SOURCE
     216  # define _XOPEN_SOURCE	700
     217  # undef  _XOPEN_SOURCE_EXTENDED
     218  # define _XOPEN_SOURCE_EXTENDED	1
     219  # undef	 _LARGEFILE64_SOURCE
     220  # define _LARGEFILE64_SOURCE	1
     221  # undef  _DEFAULT_SOURCE
     222  # define _DEFAULT_SOURCE	1
     223  # undef  _ATFILE_SOURCE
     224  # define _ATFILE_SOURCE	1
     225  # undef  _DYNAMIC_STACK_SIZE_SOURCE
     226  # define _DYNAMIC_STACK_SIZE_SOURCE 1
     227  #endif
     228  
     229  /* If nothing (other than _GNU_SOURCE and _DEFAULT_SOURCE) is defined,
     230     define _DEFAULT_SOURCE.  */
     231  #if (defined _DEFAULT_SOURCE					\
     232       || (!defined __STRICT_ANSI__				\
     233  	 && !defined _ISOC99_SOURCE && !defined _ISOC11_SOURCE	\
     234  	 && !defined _ISOC2X_SOURCE				\
     235  	 && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE	\
     236  	 && !defined _XOPEN_SOURCE))
     237  # undef  _DEFAULT_SOURCE
     238  # define _DEFAULT_SOURCE	1
     239  #endif
     240  
     241  /* This is to enable the ISO C2X extension.  */
     242  #if (defined _ISOC2X_SOURCE \
     243       || (defined __STDC_VERSION__ && __STDC_VERSION__ > 201710L))
     244  # define __GLIBC_USE_ISOC2X	1
     245  #else
     246  # define __GLIBC_USE_ISOC2X	0
     247  #endif
     248  
     249  /* This is to enable the ISO C11 extension.  */
     250  #if (defined _ISOC11_SOURCE || defined _ISOC2X_SOURCE \
     251       || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L))
     252  # define __USE_ISOC11	1
     253  #endif
     254  
     255  /* This is to enable the ISO C99 extension.  */
     256  #if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE			\
     257       || defined _ISOC2X_SOURCE						\
     258       || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L))
     259  # define __USE_ISOC99	1
     260  #endif
     261  
     262  /* This is to enable the ISO C90 Amendment 1:1995 extension.  */
     263  #if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE			\
     264       || defined _ISOC2X_SOURCE						\
     265       || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L))
     266  # define __USE_ISOC95	1
     267  #endif
     268  
     269  #ifdef __cplusplus
     270  /* This is to enable compatibility for ISO C++17.  */
     271  # if __cplusplus >= 201703L
     272  #  define __USE_ISOC11	1
     273  # endif
     274  /* This is to enable compatibility for ISO C++11.
     275     Check the temporary macro for now, too.  */
     276  # if __cplusplus >= 201103L || defined __GXX_EXPERIMENTAL_CXX0X__
     277  #  define __USE_ISOCXX11	1
     278  #  define __USE_ISOC99	1
     279  # endif
     280  #endif
     281  
     282  /* If none of the ANSI/POSIX macros are defined, or if _DEFAULT_SOURCE
     283     is defined, use POSIX.1-2008 (or another version depending on
     284     _XOPEN_SOURCE).  */
     285  #ifdef _DEFAULT_SOURCE
     286  # if !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE
     287  #  define __USE_POSIX_IMPLICITLY	1
     288  # endif
     289  # undef  _POSIX_SOURCE
     290  # define _POSIX_SOURCE	1
     291  # undef  _POSIX_C_SOURCE
     292  # define _POSIX_C_SOURCE	200809L
     293  #endif
     294  
     295  #if ((!defined __STRICT_ANSI__					\
     296        || (defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) >= 500))	\
     297       && !defined _POSIX_SOURCE && !defined _POSIX_C_SOURCE)
     298  # define _POSIX_SOURCE	1
     299  # if defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 500
     300  #  define _POSIX_C_SOURCE	2
     301  # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 600
     302  #  define _POSIX_C_SOURCE	199506L
     303  # elif defined _XOPEN_SOURCE && (_XOPEN_SOURCE - 0) < 700
     304  #  define _POSIX_C_SOURCE	200112L
     305  # else
     306  #  define _POSIX_C_SOURCE	200809L
     307  # endif
     308  # define __USE_POSIX_IMPLICITLY	1
     309  #endif
     310  
     311  /* Some C libraries once required _REENTRANT and/or _THREAD_SAFE to be
     312     defined in all multithreaded code.  GNU libc has not required this
     313     for many years.  We now treat them as compatibility synonyms for
     314     _POSIX_C_SOURCE=199506L, which is the earliest level of POSIX with
     315     comprehensive support for multithreaded code.  Using them never
     316     lowers the selected level of POSIX conformance, only raises it.  */
     317  #if ((!defined _POSIX_C_SOURCE || (_POSIX_C_SOURCE - 0) < 199506L) \
     318       && (defined _REENTRANT || defined _THREAD_SAFE))
     319  # define _POSIX_SOURCE   1
     320  # undef  _POSIX_C_SOURCE
     321  # define _POSIX_C_SOURCE 199506L
     322  #endif
     323  
     324  #if (defined _POSIX_SOURCE					\
     325       || (defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 1)	\
     326       || defined _XOPEN_SOURCE)
     327  # define __USE_POSIX	1
     328  #endif
     329  
     330  #if defined _POSIX_C_SOURCE && _POSIX_C_SOURCE >= 2 || defined _XOPEN_SOURCE
     331  # define __USE_POSIX2	1
     332  #endif
     333  
     334  #if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 199309L
     335  # define __USE_POSIX199309	1
     336  #endif
     337  
     338  #if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 199506L
     339  # define __USE_POSIX199506	1
     340  #endif
     341  
     342  #if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 200112L
     343  # define __USE_XOPEN2K		1
     344  # undef __USE_ISOC95
     345  # define __USE_ISOC95		1
     346  # undef __USE_ISOC99
     347  # define __USE_ISOC99		1
     348  #endif
     349  
     350  #if defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) >= 200809L
     351  # define __USE_XOPEN2K8		1
     352  # undef  _ATFILE_SOURCE
     353  # define _ATFILE_SOURCE	1
     354  #endif
     355  
     356  #ifdef	_XOPEN_SOURCE
     357  # define __USE_XOPEN	1
     358  # if (_XOPEN_SOURCE - 0) >= 500
     359  #  define __USE_XOPEN_EXTENDED	1
     360  #  define __USE_UNIX98	1
     361  #  undef _LARGEFILE_SOURCE
     362  #  define _LARGEFILE_SOURCE	1
     363  #  if (_XOPEN_SOURCE - 0) >= 600
     364  #   if (_XOPEN_SOURCE - 0) >= 700
     365  #    define __USE_XOPEN2K8	1
     366  #    define __USE_XOPEN2K8XSI	1
     367  #   endif
     368  #   define __USE_XOPEN2K	1
     369  #   define __USE_XOPEN2KXSI	1
     370  #   undef __USE_ISOC95
     371  #   define __USE_ISOC95		1
     372  #   undef __USE_ISOC99
     373  #   define __USE_ISOC99		1
     374  #  endif
     375  # else
     376  #  ifdef _XOPEN_SOURCE_EXTENDED
     377  #   define __USE_XOPEN_EXTENDED	1
     378  #  endif
     379  # endif
     380  #endif
     381  
     382  #ifdef _LARGEFILE_SOURCE
     383  # define __USE_LARGEFILE	1
     384  #endif
     385  
     386  #ifdef _LARGEFILE64_SOURCE
     387  # define __USE_LARGEFILE64	1
     388  #endif
     389  
     390  #if defined _FILE_OFFSET_BITS && _FILE_OFFSET_BITS == 64
     391  # define __USE_FILE_OFFSET64	1
     392  #endif
     393  
     394  #include <features-time64.h>
     395  
     396  #if defined _DEFAULT_SOURCE
     397  # define __USE_MISC	1
     398  #endif
     399  
     400  #ifdef	_ATFILE_SOURCE
     401  # define __USE_ATFILE	1
     402  #endif
     403  
     404  #ifdef	_DYNAMIC_STACK_SIZE_SOURCE
     405  # define __USE_DYNAMIC_STACK_SIZE	1
     406  #endif
     407  
     408  #ifdef	_GNU_SOURCE
     409  # define __USE_GNU	1
     410  #endif
     411  
     412  #if defined _FORTIFY_SOURCE && _FORTIFY_SOURCE > 0
     413  # if !defined __OPTIMIZE__ || __OPTIMIZE__ <= 0
     414  #  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
     415  # elif !__GNUC_PREREQ (4, 1)
     416  #  warning _FORTIFY_SOURCE requires GCC 4.1 or later
     417  # elif _FORTIFY_SOURCE > 2 && (__glibc_clang_prereq (9, 0)		      \
     418  			       || __GNUC_PREREQ (12, 0))
     419  
     420  #  if _FORTIFY_SOURCE > 3
     421  #   warning _FORTIFY_SOURCE > 3 is treated like 3 on this platform
     422  #  endif
     423  #  define __USE_FORTIFY_LEVEL 3
     424  # elif _FORTIFY_SOURCE > 1
     425  #  if _FORTIFY_SOURCE > 2
     426  #   warning _FORTIFY_SOURCE > 2 is treated like 2 on this platform
     427  #  endif
     428  #  define __USE_FORTIFY_LEVEL 2
     429  # else
     430  #  define __USE_FORTIFY_LEVEL 1
     431  # endif
     432  #endif
     433  #ifndef __USE_FORTIFY_LEVEL
     434  # define __USE_FORTIFY_LEVEL 0
     435  #endif
     436  
     437  /* The function 'gets' existed in C89, but is impossible to use
     438     safely.  It has been removed from ISO C11 and ISO C++14.  Note: for
     439     compatibility with various implementations of <cstdio>, this test
     440     must consider only the value of __cplusplus when compiling C++.  */
     441  #if defined __cplusplus ? __cplusplus >= 201402L : defined __USE_ISOC11
     442  # define __GLIBC_USE_DEPRECATED_GETS 0
     443  #else
     444  # define __GLIBC_USE_DEPRECATED_GETS 1
     445  #endif
     446  
     447  /* GNU formerly extended the scanf functions with modified format
     448     specifiers %as, %aS, and %a[...] that allocate a buffer for the
     449     input using malloc.  This extension conflicts with ISO C99, which
     450     defines %a as a standalone format specifier that reads a floating-
     451     point number; moreover, POSIX.1-2008 provides the same feature
     452     using the modifier letter 'm' instead (%ms, %mS, %m[...]).
     453  
     454     We now follow C99 unless GNU extensions are active and the compiler
     455     is specifically in C89 or C++98 mode (strict or not).  For
     456     instance, with GCC, -std=gnu11 will have C99-compliant scanf with
     457     or without -D_GNU_SOURCE, but -std=c89 -D_GNU_SOURCE will have the
     458     old extension.  */
     459  #if (defined __USE_GNU							\
     460       && (defined __cplusplus						\
     461  	 ? (__cplusplus < 201103L && !defined __GXX_EXPERIMENTAL_CXX0X__) \
     462  	 : (!defined __STDC_VERSION__ || __STDC_VERSION__ < 199901L)))
     463  # define __GLIBC_USE_DEPRECATED_SCANF 1
     464  #else
     465  # define __GLIBC_USE_DEPRECATED_SCANF 0
     466  #endif
     467  
     468  /* ISO C2X added support for a 0b or 0B prefix on binary constants as
     469     inputs to strtol-family functions (base 0 or 2).  This macro is
     470     used to condition redirection in headers to allow that redirection
     471     to be disabled when building those functions, despite _GNU_SOURCE
     472     being defined.  */
     473  #if __GLIBC_USE (ISOC2X)
     474  # define __GLIBC_USE_C2X_STRTOL 1
     475  #else
     476  # define __GLIBC_USE_C2X_STRTOL 0
     477  #endif
     478  
     479  /* Get definitions of __STDC_* predefined macros, if the compiler has
     480     not preincluded this header automatically.  */
     481  #include <stdc-predef.h>
     482  
     483  /* This macro indicates that the installed library is the GNU C Library.
     484     For historic reasons the value now is 6 and this will stay from now
     485     on.  The use of this variable is deprecated.  Use __GLIBC__ and
     486     __GLIBC_MINOR__ now (see below) when you want to test for a specific
     487     GNU C library version and use the values in <gnu/lib-names.h> to get
     488     the sonames of the shared libraries.  */
     489  #undef  __GNU_LIBRARY__
     490  #define __GNU_LIBRARY__ 6
     491  
     492  /* Major and minor version number of the GNU C library package.  Use
     493     these macros to test for features in specific releases.  */
     494  #define	__GLIBC__	2
     495  #define	__GLIBC_MINOR__	38
     496  
     497  #define __GLIBC_PREREQ(maj, min) \
     498  	((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))
     499  
     500  /* This is here only because every header file already includes this one.  */
     501  #ifndef __ASSEMBLER__
     502  # ifndef _SYS_CDEFS_H
     503  #  include <sys/cdefs.h>
     504  # endif
     505  
     506  /* If we don't have __REDIRECT, prototypes will be missing if
     507     __USE_FILE_OFFSET64 but not __USE_LARGEFILE[64]. */
     508  # if defined __USE_FILE_OFFSET64 && !defined __REDIRECT
     509  #  define __USE_LARGEFILE	1
     510  #  define __USE_LARGEFILE64	1
     511  # endif
     512  
     513  #endif	/* !ASSEMBLER */
     514  
     515  /* Decide whether we can define 'extern inline' functions in headers.  */
     516  #if __GNUC_PREREQ (2, 7) && defined __OPTIMIZE__ \
     517      && !defined __OPTIMIZE_SIZE__ && !defined __NO_INLINE__ \
     518      && defined __extern_inline
     519  # define __USE_EXTERN_INLINES	1
     520  #endif
     521  
     522  
     523  /* This is here only because every header file already includes this one.
     524     Get the definitions of all the appropriate `__stub_FUNCTION' symbols.
     525     <gnu/stubs.h> contains `#define __stub_FUNCTION' when FUNCTION is a stub
     526     that will always return failure (and set errno to ENOSYS).  */
     527  #include <gnu/stubs.h>
     528  
     529  
     530  #endif	/* features.h  */