lib/stdio-impl.h

   1 /* Implementation details of FILE streams.
   2    Copyright (C) 2007-2008, 2010-2018 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Many stdio implementations have the same logic and therefore can share
  18    the same implementation of stdio extension API, except that some fields
  19    have different naming conventions, or their access requires some casts.  */
  20
  21 /* Glibc 2.28 made _IO_IN_BACKUP private.  For now, work around this
  22    problem by defining it ourselves.  FIXME: Do not rely on glibc
  23    internals.  */
  24 #if !defined _IO_IN_BACKUP && defined _IO_EOF_SEEN
  25 # define _IO_IN_BACKUP 0x100
  26 #endif
  27
  28 /* BSD stdio derived implementations.  */
  29
  30 #if defined __NetBSD__                         /* NetBSD */
  31 /* Get __NetBSD_Version__.  */
  32 # include <sys/param.h>
  33 #endif
  34
  35 #include <errno.h>                             /* For detecting Plan9.  */
  36
  37 #if defined __sferror || defined __DragonFly__ || defined __ANDROID__
  38   /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
  39
  40 # if defined __DragonFly__          /* DragonFly */
  41   /* See <https://gitweb.dragonflybsd.org/dragonfly.git/blob_plain/HEAD:/lib/libc/stdio/priv_stdio.h>.  */
  42 #  define fp_ ((struct { struct __FILE_public pub; \
  43                          struct { unsigned char *_base; int _size; } _bf; \
  44                          void *cookie; \
  45                          void *_close; \
  46                          void *_read; \
  47                          void *_seek; \
  48                          void *_write; \
  49                          struct { unsigned char *_base; int _size; } _ub; \
  50                          int _ur; \
  51                          unsigned char _ubuf[3]; \
  52                          unsigned char _nbuf[1]; \
  53                          struct { unsigned char *_base; int _size; } _lb; \
  54                          int _blksize; \
  55                          fpos_t _offset; \
  56                          /* More fields, not relevant here.  */ \
  57                        } *) fp)
  58   /* See <https://gitweb.dragonflybsd.org/dragonfly.git/blob_plain/HEAD:/include/stdio.h>.  */
  59 #  define _p pub._p
  60 #  define _flags pub._flags
  61 #  define _r pub._r
  62 #  define _w pub._w
  63 # elif defined __ANDROID__ /* Android */
  64   /* Up to this commit from 2015-10-12
  65      <https://android.googlesource.com/platform/bionic.git/+/f0141dfab10a4b332769d52fa76631a64741297a>
  66      the innards of FILE were public, and fp_ub could be defined like for OpenBSD,
  67      see <https://android.googlesource.com/platform/bionic.git/+/e78392637d5086384a5631ddfdfa8d7ec8326ee3/libc/stdio/fileext.h>
  68      and <https://android.googlesource.com/platform/bionic.git/+/e78392637d5086384a5631ddfdfa8d7ec8326ee3/libc/stdio/local.h>.
  69      After this commit, the innards of FILE are hidden.  */
  70 #  define fp_ ((struct { unsigned char *_p; \
  71                          int _r; \
  72                          int _w; \
  73                          int _flags; \
  74                          int _file; \
  75                          struct { unsigned char *_base; size_t _size; } _bf; \
  76                          int _lbfsize; \
  77                          void *_cookie; \
  78                          void *_close; \
  79                          void *_read; \
  80                          void *_seek; \
  81                          void *_write; \
  82                          struct { unsigned char *_base; size_t _size; } _ext; \
  83                          unsigned char *_up; \
  84                          int _ur; \
  85                          unsigned char _ubuf[3]; \
  86                          unsigned char _nbuf[1]; \
  87                          struct { unsigned char *_base; size_t _size; } _lb; \
  88                          int _blksize; \
  89                          fpos_t _offset; \
  90                          /* More fields, not relevant here.  */ \
  91                        } *) fp)
  92 # else
  93 #  define fp_ fp
  94 # endif
  95
  96 # if (defined __NetBSD__ && __NetBSD_Version__ >= 105270000) || defined __OpenBSD__ || defined __minix /* NetBSD >= 1.5ZA, OpenBSD, Minix 3 */
  97   /* See <http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup>
  98      and <https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup>
  99      and <https://github.com/Stichting-MINIX-Research-Foundation/minix/blob/master/lib/libc/stdio/fileext.h> */
 100   struct __sfileext
 101     {
 102       struct  __sbuf _ub; /* ungetc buffer */
 103       /* More fields, not relevant here.  */
 104     };
 105 #  define fp_ub ((struct __sfileext *) fp->_ext._base)->_ub
 106 # elif defined __ANDROID__                     /* Android */
 107   struct __sfileext
 108     {
 109       struct { unsigned char *_base; size_t _size; } _ub; /* ungetc buffer */
 110       /* More fields, not relevant here.  */
 111     };
 112 #  define fp_ub ((struct __sfileext *) fp_->_ext._base)->_ub
 113 # else                                         /* FreeBSD, NetBSD <= 1.5Z, DragonFly, Mac OS X, Cygwin */
 114 #  define fp_ub fp_->_ub
 115 # endif
 116
 117 # define HASUB(fp) (fp_ub._base != NULL)
 118
 119 # if defined __ANDROID__ /* Android */
 120   /* Needed after this commit from 2016-01-25
 121      <https://android.googlesource.com/platform/bionic.git/+/e70e0e9267d069bf56a5078c99307e08a7280de7> */
 122 #  ifndef __SEOF
 123 #   define __SLBF 1
 124 #   define __SNBF 2
 125 #   define __SRD 4
 126 #   define __SWR 8
 127 #   define __SRW 0x10
 128 #   define __SEOF 0x20
 129 #   define __SERR 0x40
 130 #  endif
 131 #  ifndef __SOFF
 132 #   define __SOFF 0x1000
 133 #  endif
 134 # endif
 135
 136 #endif
 137
 138
 139 /* SystemV derived implementations.  */
 140
 141 #ifdef __TANDEM                     /* NonStop Kernel */
 142 # ifndef _IOERR
 143 /* These values were determined by the program 'stdioext-flags' at
 144    <https://lists.gnu.org/r/bug-gnulib/2010-12/msg00165.html>.  */
 145 #  define _IOERR   0x40
 146 #  define _IOREAD  0x80
 147 #  define _IOWRT    0x4
 148 #  define _IORW   0x100
 149 # endif
 150 #endif
 151
 152 #if defined _IOERR
 153
 154 # if defined __sun && defined _LP64 /* Solaris/{SPARC,AMD64} 64-bit */
 155 #  define fp_ ((struct { unsigned char *_ptr; \
 156                          unsigned char *_base; \
 157                          unsigned char *_end; \
 158                          long _cnt; \
 159                          int _file; \
 160                          unsigned int _flag; \
 161                        } *) fp)
 162 # elif defined __VMS                /* OpenVMS */
 163 #  define fp_ ((struct _iobuf *) fp)
 164 # else
 165 #  define fp_ fp
 166 # endif
 167
 168 # if defined _SCO_DS                /* OpenServer */
 169 #  define _cnt __cnt
 170 #  define _ptr __ptr
 171 #  define _base __base
 172 #  define _flag __flag
 173 # endif
 174
 175 #elif defined _WIN32 && ! defined __CYGWIN__  /* newer Windows with MSVC */
 176
 177 /* <stdio.h> does not define the innards of FILE any more.  */
 178 # define WINDOWS_OPAQUE_FILE
 179
 180 struct _gl_real_FILE
 181 {
 182   /* Note: Compared to older Windows and to mingw, it has the fields
 183      _base and _cnt swapped. */
 184   unsigned char *_ptr;
 185   unsigned char *_base;
 186   int _cnt;
 187   int _flag;
 188   int _file;
 189   int _charbuf;
 190   int _bufsiz;
 191 };
 192 # define fp_ ((struct _gl_real_FILE *) fp)
 193
 194 /* These values were determined by a program similar to the one at
 195    <https://lists.gnu.org/r/bug-gnulib/2010-12/msg00165.html>.  */
 196 # define _IOREAD   0x1
 197 # define _IOWRT    0x2
 198 # define _IORW     0x4
 199 # define _IOEOF    0x8
 200 # define _IOERR   0x10
 201
 202 #endif