libio/libio.h

   1 /* Copyright (C) 1991-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Written by Per Bothner <bothner@cygnus.com>.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.
  18
  19    As a special exception, if you link the code in this file with
  20    files compiled with a GNU compiler to produce an executable,
  21    that does not cause the resulting executable to be covered by
  22    the GNU Lesser General Public License.  This exception does not
  23    however invalidate any other reasons why the executable file
  24    might be covered by the GNU Lesser General Public License.
  25    This exception applies to code released by its copyright holders
  26    in files containing the exception.  */
  27
  28 #ifndef _LIBIO_H
  29 #define _LIBIO_H 1
  30
  31 #ifndef _LIBC
  32 # error "libio.h should only be included when building glibc itself"
  33 #endif
  34 #ifdef _ISOMAC
  35 # error "libio.h should not be included under _ISOMAC"
  36 #endif
  37
  38 #include <stdio.h>
  39
  40 #if defined _IO_MTSAFE_IO && !defined _IO_lock_t_defined
  41 # error "Someone forgot to include stdio-lock.h"
  42 #endif
  43
  44 #define __need_wchar_t
  45 #include <stddef.h>
  46
  47 #include <bits/types/__mbstate_t.h>
  48 #include <bits/types/wint_t.h>
  49 #include <gconv.h>
  50
  51 typedef struct
  52 {
  53   struct __gconv_step *step;
  54   struct __gconv_step_data step_data;
  55 } _IO_iconv_t;
  56
  57 #include <shlib-compat.h>
  58
  59 /* _IO_seekoff modes */
  60 #define _IOS_INPUT      1
  61 #define _IOS_OUTPUT     2
  62
  63 /* Magic number and bits for the _flags field.  The magic number is
  64    mostly vestigial, but preserved for compatibility.  It occupies the
  65    high 16 bits of _flags; the low 16 bits are actual flag bits.  */
  66
  67 #define _IO_MAGIC         0xFBAD0000 /* Magic number */
  68 #define _IO_MAGIC_MASK    0xFFFF0000
  69 #define _IO_USER_BUF          0x0001 /* Don't deallocate buffer on close. */
  70 #define _IO_UNBUFFERED        0x0002
  71 #define _IO_NO_READS          0x0004 /* Reading not allowed.  */
  72 #define _IO_NO_WRITES         0x0008 /* Writing not allowed.  */
  73 #define _IO_EOF_SEEN          0x0010
  74 #define _IO_ERR_SEEN          0x0020
  75 #define _IO_DELETE_DONT_CLOSE 0x0040 /* Don't call close(_fileno) on close.  */
  76 #define _IO_LINKED            0x0080 /* In the list of all open files.  */
  77 #define _IO_IN_BACKUP         0x0100
  78 #define _IO_LINE_BUF          0x0200
  79 #define _IO_TIED_PUT_GET      0x0400 /* Put and get pointer move in unison.  */
  80 #define _IO_CURRENTLY_PUTTING 0x0800
  81 #define _IO_IS_APPENDING      0x1000
  82 #define _IO_IS_FILEBUF        0x2000
  83                            /* 0x4000  No longer used, reserved for compat.  */
  84 #define _IO_USER_LOCK         0x8000
  85
  86 /* Bits for the _flags2 field.  */
  87 #define _IO_FLAGS2_MMAP 1
  88 #define _IO_FLAGS2_NOTCANCEL 2
  89 #define _IO_FLAGS2_USER_WBUF 8
  90 #define _IO_FLAGS2_NOCLOSE 32
  91 #define _IO_FLAGS2_CLOEXEC 64
  92 #define _IO_FLAGS2_NEED_LOCK 128
  93
  94 /* _IO_pos_BAD is an off64_t value indicating error, unknown, or EOF.  */
  95 #define _IO_pos_BAD ((off64_t) -1)
  96
  97 /* _IO_pos_adjust adjusts an off64_t by some number of bytes.  */
  98 #define _IO_pos_adjust(pos, delta) ((pos) += (delta))
  99
 100 /* _IO_pos_0 is an off64_t value indicating beginning of file.  */
 101 #define _IO_pos_0 ((off64_t) 0)
 102
 103 struct _IO_jump_t;
 104
 105 /* A streammarker remembers a position in a buffer. */
 106 struct _IO_marker {
 107   struct _IO_marker *_next;
 108   FILE *_sbuf;
 109   /* If _pos >= 0
 110  it points to _buf->Gbase()+_pos. FIXME comment */
 111   /* if _pos < 0, it points to _buf->eBptr()+_pos. FIXME comment */
 112   int _pos;
 113 };
 114
 115 struct _IO_codecvt
 116 {
 117   _IO_iconv_t __cd_in;
 118   _IO_iconv_t __cd_out;
 119 };
 120
 121 /* Extra data for wide character streams.  */
 122 struct _IO_wide_data
 123 {
 124   wchar_t *_IO_read_ptr;        /* Current read pointer */
 125   wchar_t *_IO_read_end;        /* End of get area. */
 126   wchar_t *_IO_read_base;       /* Start of putback+get area. */
 127   wchar_t *_IO_write_base;      /* Start of put area. */
 128   wchar_t *_IO_write_ptr;       /* Current put pointer. */
 129   wchar_t *_IO_write_end;       /* End of put area. */
 130   wchar_t *_IO_buf_base;        /* Start of reserve area. */
 131   wchar_t *_IO_buf_end;         /* End of reserve area. */
 132   /* The following fields are used to support backing up and undo. */
 133   wchar_t *_IO_save_base;       /* Pointer to start of non-current get area. */
 134   wchar_t *_IO_backup_base;     /* Pointer to first valid character of
 135                                    backup area */
 136   wchar_t *_IO_save_end;        /* Pointer to end of non-current get area. */
 137
 138   __mbstate_t _IO_state;
 139   __mbstate_t _IO_last_state;
 140   struct _IO_codecvt _codecvt;
 141
 142   wchar_t _shortbuf[1];
 143
 144   const struct _IO_jump_t *_wide_vtable;
 145 };
 146
 147 struct _IO_FILE_plus;
 148
 149 extern struct _IO_FILE_plus _IO_2_1_stdin_;
 150 extern struct _IO_FILE_plus _IO_2_1_stdout_;
 151 extern struct _IO_FILE_plus _IO_2_1_stderr_;
 152
 153 struct _IO_cookie_file;
 154
 155 /* Initialize one of those.  */
 156 extern void _IO_cookie_init (struct _IO_cookie_file *__cfile, int __read_write,
 157                              void *__cookie, cookie_io_functions_t __fns);
 158
 159 extern int __underflow (FILE *);
 160 extern wint_t __wunderflow (FILE *);
 161 extern wint_t __wuflow (FILE *);
 162 extern wint_t __woverflow (FILE *, wint_t);
 163
 164 #define _IO_getc_unlocked(_fp) __getc_unlocked_body (_fp)
 165 #define _IO_peekc_unlocked(_fp)                                         \
 166   (__glibc_unlikely ((_fp)->_IO_read_ptr >= (_fp)->_IO_read_end)        \
 167    && __underflow (_fp) == EOF                                          \
 168    ? EOF                                                                \
 169    : *(unsigned char *) (_fp)->_IO_read_ptr)
 170 #define _IO_putc_unlocked(_ch, _fp) __putc_unlocked_body (_ch, _fp)
 171
 172 # define _IO_getwc_unlocked(_fp)                                        \
 173   (__glibc_unlikely ((_fp)->_wide_data == NULL                          \
 174                      || ((_fp)->_wide_data->_IO_read_ptr                \
 175                          >= (_fp)->_wide_data->_IO_read_end))           \
 176    ? __wuflow (_fp) : (wint_t) *(_fp)->_wide_data->_IO_read_ptr++)
 177 # define _IO_putwc_unlocked(_wch, _fp)                                  \
 178   (__glibc_unlikely ((_fp)->_wide_data == NULL                          \
 179                      || ((_fp)->_wide_data->_IO_write_ptr               \
 180                          >= (_fp)->_wide_data->_IO_write_end))          \
 181    ? __woverflow (_fp, _wch)                                            \
 182    : (wint_t) (*(_fp)->_wide_data->_IO_write_ptr++ = (_wch)))
 183
 184 #define _IO_feof_unlocked(_fp) __feof_unlocked_body (_fp)
 185 #define _IO_ferror_unlocked(_fp) __ferror_unlocked_body (_fp)
 186
 187 extern int _IO_getc (FILE *__fp);
 188 extern int _IO_putc (int __c, FILE *__fp);
 189 extern int _IO_feof (FILE *__fp) __THROW;
 190 extern int _IO_ferror (FILE *__fp) __THROW;
 191
 192 extern int _IO_peekc_locked (FILE *__fp);
 193
 194 /* This one is for Emacs. */
 195 #define _IO_PENDING_OUTPUT_COUNT(_fp)   \
 196         ((_fp)->_IO_write_ptr - (_fp)->_IO_write_base)
 197
 198 extern void _IO_flockfile (FILE *) __THROW;
 199 extern void _IO_funlockfile (FILE *) __THROW;
 200 extern int _IO_ftrylockfile (FILE *) __THROW;
 201
 202 #define _IO_peekc(_fp) _IO_peekc_unlocked (_fp)
 203 #define _IO_flockfile(_fp) /**/
 204 #define _IO_funlockfile(_fp) ((void) 0)
 205 #define _IO_ftrylockfile(_fp) /**/
 206 #ifndef _IO_cleanup_region_start
 207 #define _IO_cleanup_region_start(_fct, _fp) /**/
 208 #endif
 209 #ifndef _IO_cleanup_region_end
 210 #define _IO_cleanup_region_end(_Doit) /**/
 211 #endif
 212
 213 #define _IO_need_lock(_fp) \
 214   (((_fp)->_flags2 & _IO_FLAGS2_NEED_LOCK) != 0)
 215
 216 extern int _IO_vfscanf (FILE * __restrict, const char * __restrict,
 217                         __gnuc_va_list, int *__restrict);
 218 extern __ssize_t _IO_padn (FILE *, int, __ssize_t);
 219 extern size_t _IO_sgetn (FILE *, void *, size_t);
 220
 221 extern off64_t _IO_seekoff (FILE *, off64_t, int, int);
 222 extern off64_t _IO_seekpos (FILE *, off64_t, int);
 223
 224 extern void _IO_free_backup_area (FILE *) __THROW;
 225
 226
 227 extern wint_t _IO_getwc (FILE *__fp);
 228 extern wint_t _IO_putwc (wchar_t __wc, FILE *__fp);
 229 extern int _IO_fwide (FILE *__fp, int __mode) __THROW;
 230
 231 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
 232 #  define _IO_fwide_maybe_incompatible \
 233   (__glibc_unlikely (&_IO_stdin_used == NULL))
 234 extern const int _IO_stdin_used;
 235 weak_extern (_IO_stdin_used);
 236 #else
 237 # define _IO_fwide_maybe_incompatible (0)
 238 #endif
 239
 240 /* A special optimized version of the function above.  It optimizes the
 241    case of initializing an unoriented byte stream.  */
 242 #define _IO_fwide(__fp, __mode) \
 243   ({ int __result = (__mode);                                                 \
 244      if (__result < 0 && ! _IO_fwide_maybe_incompatible)                      \
 245        {                                                                      \
 246          if ((__fp)->_mode == 0)                                              \
 247            /* We know that all we have to do is to set the flag.  */          \
 248            (__fp)->_mode = -1;                                                \
 249          __result = (__fp)->_mode;                                            \
 250        }                                                                      \
 251      else if (__builtin_constant_p (__mode) && (__mode) == 0)                 \
 252        __result = _IO_fwide_maybe_incompatible ? -1 : (__fp)->_mode;          \
 253      else                                                                     \
 254        __result = _IO_fwide (__fp, __result);                                 \
 255      __result; })
 256
 257 extern int _IO_vfwscanf (FILE * __restrict, const wchar_t * __restrict,
 258                          __gnuc_va_list, int *__restrict);
 259 extern __ssize_t _IO_wpadn (FILE *, wint_t, __ssize_t);
 260 extern void _IO_free_wbackup_area (FILE *) __THROW;
 261
 262 #ifdef __LDBL_COMPAT
 263 __LDBL_REDIR_DECL (_IO_vfscanf)
 264 #endif
 265
 266 libc_hidden_proto (__overflow)
 267 libc_hidden_proto (__underflow)
 268 libc_hidden_proto (__uflow)
 269 libc_hidden_proto (__woverflow)
 270 libc_hidden_proto (__wunderflow)
 271 libc_hidden_proto (__wuflow)
 272 libc_hidden_proto (_IO_free_backup_area)
 273 libc_hidden_proto (_IO_free_wbackup_area)
 274 libc_hidden_proto (_IO_padn)
 275 libc_hidden_proto (_IO_putc)
 276 libc_hidden_proto (_IO_sgetn)
 277
 278 #ifdef _IO_MTSAFE_IO
 279 # undef _IO_peekc
 280 # undef _IO_flockfile
 281 # undef _IO_funlockfile
 282 # undef _IO_ftrylockfile
 283
 284 # define _IO_peekc(_fp) _IO_peekc_locked (_fp)
 285 # if _IO_lock_inexpensive
 286 #  define _IO_flockfile(_fp) \
 287   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_lock (*(_fp)->_lock)
 288 #  define _IO_funlockfile(_fp) \
 289   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_unlock (*(_fp)->_lock)
 290 # else
 291 #  define _IO_flockfile(_fp) \
 292   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_flockfile (_fp)
 293 #  define _IO_funlockfile(_fp) \
 294   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_funlockfile (_fp)
 295 # endif
 296 #endif /* _IO_MTSAFE_IO */
 297
 298 #endif /* _LIBIO_H */