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 # else
  64 #  define fp_ fp
  65 # endif
  66
  67 # if (defined __NetBSD__ && __NetBSD_Version__ >= 105270000) || defined __OpenBSD__ || defined __minix || defined __ANDROID__ /* NetBSD >= 1.5ZA, OpenBSD, Minix 3, Android */
  68   /* See <http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup>
  69      and <https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdio/fileext.h?rev=HEAD&content-type=text/x-cvsweb-markup> */
  70   struct __sfileext
  71     {
  72       struct  __sbuf _ub; /* ungetc buffer */
  73       /* More fields, not relevant here.  */
  74     };
  75 #  define fp_ub ((struct __sfileext *) fp->_ext._base)->_ub
  76 # else                                         /* FreeBSD, NetBSD <= 1.5Z, DragonFly, Mac OS X, Cygwin, Android */
  77 #  define fp_ub fp_->_ub
  78 # endif
  79
  80 # define HASUB(fp) (fp_ub._base != NULL)
  81
  82 #endif
  83
  84
  85 /* SystemV derived implementations.  */
  86
  87 #ifdef __TANDEM                     /* NonStop Kernel */
  88 # ifndef _IOERR
  89 /* These values were determined by the program 'stdioext-flags' at
  90    <https://lists.gnu.org/r/bug-gnulib/2010-12/msg00165.html>.  */
  91 #  define _IOERR   0x40
  92 #  define _IOREAD  0x80
  93 #  define _IOWRT    0x4
  94 #  define _IORW   0x100
  95 # endif
  96 #endif
  97
  98 #if defined _IOERR
  99
 100 # if defined __sun && defined _LP64 /* Solaris/{SPARC,AMD64} 64-bit */
 101 #  define fp_ ((struct { unsigned char *_ptr; \
 102                          unsigned char *_base; \
 103                          unsigned char *_end; \
 104                          long _cnt; \
 105                          int _file; \
 106                          unsigned int _flag; \
 107                        } *) fp)
 108 # elif defined __VMS                /* OpenVMS */
 109 #  define fp_ ((struct _iobuf *) fp)
 110 # else
 111 #  define fp_ fp
 112 # endif
 113
 114 # if defined _SCO_DS                /* OpenServer */
 115 #  define _cnt __cnt
 116 #  define _ptr __ptr
 117 #  define _base __base
 118 #  define _flag __flag
 119 # endif
 120
 121 #elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__  /* newer Windows with MSVC */
 122
 123 /* <stdio.h> does not define the innards of FILE any more.  */
 124 # define WINDOWS_OPAQUE_FILE
 125
 126 struct _gl_real_FILE
 127 {
 128   /* Note: Compared to older Windows and to mingw, it has the fields
 129      _base and _cnt swapped. */
 130   unsigned char *_ptr;
 131   unsigned char *_base;
 132   int _cnt;
 133   int _flag;
 134   int _file;
 135   int _charbuf;
 136   int _bufsiz;
 137 };
 138 # define fp_ ((struct _gl_real_FILE *) fp)
 139
 140 /* These values were determined by a program similar to the one at
 141    <https://lists.gnu.org/r/bug-gnulib/2010-12/msg00165.html>.  */
 142 # define _IOREAD   0x1
 143 # define _IOWRT    0x2
 144 # define _IORW     0x4
 145 # define _IOEOF    0x8
 146 # define _IOERR   0x10
 147
 148 #endif