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The C and C++ Include Header Files

/usr/include/x86_64-linux-gnu/bits/environments.h


$ cat -n /usr/include/x86_64-linux-gnu/bits/environments.h

     1	/* Copyright (C) 1999-2024 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 _UNISTD_H
    19	# error "Never include this file directly.  Use <unistd.h> instead"
    20	#endif
    21	
    22	#include <bits/wordsize.h>
    23	
    24	/* This header should define the following symbols under the described
    25	   situations.  A value `1' means that the model is always supported,
    26	   `-1' means it is never supported.  Undefined means it cannot be
    27	   statically decided.
    28	
    29	   _POSIX_V7_ILP32_OFF32   32bit int, long, pointers, and off_t type
    30	   _POSIX_V7_ILP32_OFFBIG  32bit int, long, and pointers and larger off_t type
    31	
    32	   _POSIX_V7_LP64_OFF32	   64bit long and pointers and 32bit off_t type
    33	   _POSIX_V7_LPBIG_OFFBIG  64bit long and pointers and large off_t type
    34	
    35	   The macros _POSIX_V6_ILP32_OFF32, _POSIX_V6_ILP32_OFFBIG,
    36	   _POSIX_V6_LP64_OFF32, _POSIX_V6_LPBIG_OFFBIG, _XBS5_ILP32_OFF32,
    37	   _XBS5_ILP32_OFFBIG, _XBS5_LP64_OFF32, and _XBS5_LPBIG_OFFBIG were
    38	   used in previous versions of the Unix standard and are available
    39	   only for compatibility.
    40	*/
    41	
    42	#if __WORDSIZE == 64
    43	
    44	/* Environments with 32-bit wide pointers are optionally provided.
    45	   Therefore following macros aren't defined:
    46	   # undef _POSIX_V7_ILP32_OFF32
    47	   # undef _POSIX_V7_ILP32_OFFBIG
    48	   # undef _POSIX_V6_ILP32_OFF32
    49	   # undef _POSIX_V6_ILP32_OFFBIG
    50	   # undef _XBS5_ILP32_OFF32
    51	   # undef _XBS5_ILP32_OFFBIG
    52	   and users need to check at runtime.  */
    53	
    54	/* We also have no use (for now) for an environment with bigger pointers
    55	   and offsets.  */
    56	# define _POSIX_V7_LPBIG_OFFBIG	-1
    57	# define _POSIX_V6_LPBIG_OFFBIG	-1
    58	# define _XBS5_LPBIG_OFFBIG	-1
    59	
    60	/* By default we have 64-bit wide `long int', pointers and `off_t'.  */
    61	# define _POSIX_V7_LP64_OFF64	1
    62	# define _POSIX_V6_LP64_OFF64	1
    63	# define _XBS5_LP64_OFF64	1
    64	
    65	#else /* __WORDSIZE == 32 */
    66	
    67	/* We have 32-bit wide `int', `long int' and pointers and all platforms
    68	   support LFS.  -mx32 has 64-bit wide `off_t'.  */
    69	# define _POSIX_V7_ILP32_OFFBIG	1
    70	# define _POSIX_V6_ILP32_OFFBIG 1
    71	# define _XBS5_ILP32_OFFBIG	1
    72	
    73	# ifndef __x86_64__
    74	/* -m32 has 32-bit wide `off_t'.  */
    75	#  define _POSIX_V7_ILP32_OFF32	1
    76	#  define _POSIX_V6_ILP32_OFF32	1
    77	#  define _XBS5_ILP32_OFF32	1
    78	# endif
    79	
    80	/* We optionally provide an environment with the above size but an 64-bit
    81	   side `off_t'.  Therefore we don't define _POSIX_V7_ILP32_OFFBIG.  */
    82	
    83	/* Environments with 64-bit wide pointers can be provided,
    84	   so these macros aren't defined:
    85	   # undef _POSIX_V7_LP64_OFF64
    86	   # undef _POSIX_V7_LPBIG_OFFBIG
    87	   # undef _POSIX_V6_LP64_OFF64
    88	   # undef _POSIX_V6_LPBIG_OFFBIG
    89	   # undef _XBS5_LP64_OFF64
    90	   # undef _XBS5_LPBIG_OFFBIG
    91	   and sysconf tests for it at runtime.  */
    92	
    93	#endif /* __WORDSIZE == 32 */
    94	
    95	#define __ILP32_OFF32_CFLAGS	"-m32"
    96	#define __ILP32_OFF32_LDFLAGS	"-m32"
    97	#if defined __x86_64__ && defined __ILP32__
    98	# define __ILP32_OFFBIG_CFLAGS	"-mx32"
    99	# define __ILP32_OFFBIG_LDFLAGS	"-mx32"
   100	#else
   101	# define __ILP32_OFFBIG_CFLAGS	"-m32 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
   102	# define __ILP32_OFFBIG_LDFLAGS	"-m32"
   103	#endif
   104	#define __LP64_OFF64_CFLAGS	"-m64"
   105	#define __LP64_OFF64_LDFLAGS	"-m64"