lib/stdio-impl.h

   1 /* Implementation details of FILE streams.
   2    Copyright (C) 2007-2008, 2010-2020 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_UNBUFFERED and _IO_IN_BACKUP private.  For now, work
  22    around this problem by defining them ourselves.  FIXME: Do not rely on glibc
  23    internals.  */
  24 #if defined _IO_EOF_SEEN
  25 # if !defined _IO_UNBUFFERED
  26 #  define _IO_UNBUFFERED 0x2
  27 # endif
  28 # if !defined _IO_IN_BACKUP
  29 #  define _IO_IN_BACKUP 0x100
  30 # endif
  31 #endif
  32
  33 /* BSD stdio derived implementations.  */
  34
  35 #if defined __NetBSD__                         /* NetBSD */
  36 /* Get __NetBSD_Version__.  */
  37 # include <sys/param.h>
  38 #endif
  39
  40 #include <errno.h>                             /* For detecting Plan9.  */
  41
  42 #if defined __sferror || defined __DragonFly__ || defined __ANDROID__
  43   /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
  44
  45 # if defined __DragonFly__          /* DragonFly */
  46   /* See <https://gitweb.dragonflybsd.org/dragonfly.git/blob_plain/HEAD:/lib/libc/stdio/priv_stdio.h>.  */
  47 #  define fp_ ((struct { struct __FILE_public pub; \
  48                          struct { unsigned char *_base; int _size; } _bf; \
  49                          void *cookie; \
  50                          void *_close; \
  51                          void *_read; \
  52                          void *_seek; \
  53                          void *_write; \
  54                          struct { unsigned char *_base; int _size; } _ub; \
  55                          int _ur; \
  56                          unsigned char _ubuf[3]; \
  57                          unsigned char _nbuf[1]; \
  58                          struct { unsigned char *_base; int _size; } _lb; \
  59                          int _blksize; \
  60                          fpos_t _offset; \
  61                          /* More fields, not relevant here.  */ \
  62                        } *) fp)
  63   /* See <https://gitweb.dragonflybsd.org/dragonfly.git/blob_plain/HEAD:/include/stdio.h>.  */
  64 #  define _p pub._p
  65 #  define _flags pub._flags
  66 #  define _r pub._r
  67 #  define _w pub._w
  68 # elif defined __ANDROID__ /* Android */
  69 #  ifdef __LP64__
  70 #   define _gl_flags_file_t int
  71 #  else
  72 #   define _gl_flags_file_t short
  73 #  endif
  74   /* Up to this commit from 2015-10-12
  75      <https://android.googlesource.com/platform/bionic.git/+/f0141dfab10a4b332769d52fa76631a64741297a>
  76      the innards of FILE were public, and fp_ub could be defined like for OpenBSD,
  77      see <https://android.googlesource.com/platform/bionic.git/+/e78392637d5086384a5631ddfdfa8d7ec8326ee3/libc/stdio/fileext.h>
  78      and <https://android.googlesource.com/platform/bionic.git/+/e78392637d5086384a5631ddfdfa8d7ec8326ee3/libc/stdio/local.h>.
  79      After this commit, the innards of FILE are hidden.  */
  80 #  define fp_ ((struct { unsigned char *_p; \
  81                          int _r; \
  82                          int _w; \
  83                          _gl_flags_file_t _flags; \
  84                          _gl_flags_file_t _file; \
  85                          struct { unsigned char *_base; size_t _size; } _bf; \
  86                          int _lbfsize; \
  87                          void *_cookie; \
  88                          void *_close; \
  89                          void *_read; \
  90                          void *_seek; \
  91                          void *_write; \
  92                          struct { unsigned char *_base; size_t _size; } _ext; \
  93                          unsigned char *_up; \
  94                          int _ur; \
  95                          unsigned char _ubuf[3]; \
  96                          unsigned char _nbuf[1]; \
  97                          struct { unsigned char *_base; size_t _size; } _lb; \
  98                          int _blksize; \
  99                          fpos_t _offset; \
 100                          /* More fields, not relevant here.  */ \
 101                        } *) fp)
 102 # else
 103 #  define fp_ fp
 104 # endif
 105
 106 # if (defined __NetBSD__ && __NetBSD_Version__ >= 105270000) || defined __OpenBSD__ || defined __minix /* NetBSD >= 1.5ZA, OpenBSD, Minix 3 */
 107   /* See <http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup>
 108      and <https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup>
 109      and <https://github.com/Stichting-MINIX-Research-Foundation/minix/blob/master/lib/libc/stdio/fileext.h> */
 110   struct __sfileext
 111     {
 112       struct  __sbuf _ub; /* ungetc buffer */
 113       /* More fields, not relevant here.  */
 114     };
 115 #  define fp_ub ((struct __sfileext *) fp->_ext._base)->_ub
 116 # elif defined __ANDROID__                     /* Android */
 117   struct __sfileext
 118     {
 119       struct { unsigned char *_base; size_t _size; } _ub; /* ungetc buffer */
 120       /* More fields, not relevant here.  */
 121     };
 122 #  define fp_ub ((struct __sfileext *) fp_->_ext._base)->_ub
 123 # else                                         /* FreeBSD, NetBSD <= 1.5Z, DragonFly, Mac OS X, Cygwin */
 124 #  define fp_ub fp_->_ub
 125 # endif
 126
 127 # define HASUB(fp) (fp_ub._base != NULL)
 128
 129 # if defined __ANDROID__ /* Android */
 130   /* Needed after this commit from 2016-01-25
 131      <https://android.googlesource.com/platform/bionic.git/+/e70e0e9267d069bf56a5078c99307e08a7280de7> */
 132 #  ifndef __SEOF
 133 #   define __SLBF 1
 134 #   define __SNBF 2
 135 #   define __SRD 4
 136 #   define __SWR 8
 137 #   define __SRW 0x10
 138 #   define __SEOF 0x20
 139 #   define __SERR 0x40
 140 #  endif
 141 #  ifndef __SOFF
 142 #   define __SOFF 0x1000
 143 #  endif
 144 # endif
 145
 146 #endif
 147
 148
 149 /* SystemV derived implementations.  */
 150
 151 #ifdef __TANDEM                     /* NonStop Kernel */
 152 # ifndef _IOERR
 153 /* These values were determined by the program 'stdioext-flags' at
 154    <https://lists.gnu.org/r/bug-gnulib/2010-12/msg00165.html>.  */
 155 #  define _IOERR   0x40
 156 #  define _IOREAD  0x80
 157 #  define _IOWRT    0x4
 158 #  define _IORW   0x100
 159 # endif
 160 #endif
 161
 162 #if defined _IOERR
 163
 164 # if defined __sun && defined _LP64 /* Solaris/{SPARC,AMD64} 64-bit */
 165 #  define fp_ ((struct { unsigned char *_ptr; \
 166                          unsigned char *_base; \
 167                          unsigned char *_end; \
 168                          long _cnt; \
 169                          int _file; \
 170                          unsigned int _flag; \
 171                        } *) fp)
 172 # elif defined __VMS                /* OpenVMS */
 173 #  define fp_ ((struct _iobuf *) fp)
 174 # else
 175 #  define fp_ fp
 176 # endif
 177
 178 # if defined _SCO_DS                /* OpenServer */
 179 #  define _cnt __cnt
 180 #  define _ptr __ptr
 181 #  define _base __base
 182 #  define _flag __flag
 183 # endif
 184
 185 #elif defined _WIN32 && ! defined __CYGWIN__  /* newer Windows with MSVC */
 186
 187 /* <stdio.h> does not define the innards of FILE any more.  */
 188 # define WINDOWS_OPAQUE_FILE
 189
 190 struct _gl_real_FILE
 191 {
 192   /* Note: Compared to older Windows and to mingw, it has the fields
 193      _base and _cnt swapped. */
 194   unsigned char *_ptr;
 195   unsigned char *_base;
 196   int _cnt;
 197   int _flag;
 198   int _file;
 199   int _charbuf;
 200   int _bufsiz;
 201 };
 202 # define fp_ ((struct _gl_real_FILE *) fp)
 203
 204 /* These values were determined by a program similar to the one at
 205    <https://lists.gnu.org/r/bug-gnulib/2010-12/msg00165.html>.  */
 206 # define _IOREAD   0x1
 207 # define _IOWRT    0x2
 208 # define _IORW     0x4
 209 # define _IOEOF    0x8
 210 # define _IOERR   0x10
 211
 212 #endif