libio/libio.h

   1 /* Copyright (C) 1991-2019 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    <http://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 union
  52 {
  53   struct __gconv_info __cd;
  54   struct
  55   {
  56     struct __gconv_info __cd;
  57     struct __gconv_step_data __data;
  58   } __combined;
  59 } _IO_iconv_t;
  60
  61 #include <shlib-compat.h>
  62
  63 /* _IO_seekoff modes */
  64 #define _IOS_INPUT      1
  65 #define _IOS_OUTPUT     2
  66
  67 /* Magic number and bits for the _flags field.  The magic number is
  68    mostly vestigial, but preserved for compatibility.  It occupies the
  69    high 16 bits of _flags; the low 16 bits are actual flag bits.  */
  70
  71 #define _IO_MAGIC         0xFBAD0000 /* Magic number */
  72 #define _IO_MAGIC_MASK    0xFFFF0000
  73 #define _IO_USER_BUF          0x0001 /* Don't deallocate buffer on close. */
  74 #define _IO_UNBUFFERED        0x0002
  75 #define _IO_NO_READS          0x0004 /* Reading not allowed.  */
  76 #define _IO_NO_WRITES         0x0008 /* Writing not allowed.  */
  77 #define _IO_EOF_SEEN          0x0010
  78 #define _IO_ERR_SEEN          0x0020
  79 #define _IO_DELETE_DONT_CLOSE 0x0040 /* Don't call close(_fileno) on close.  */
  80 #define _IO_LINKED            0x0080 /* In the list of all open files.  */
  81 #define _IO_IN_BACKUP         0x0100
  82 #define _IO_LINE_BUF          0x0200
  83 #define _IO_TIED_PUT_GET      0x0400 /* Put and get pointer move in unison.  */
  84 #define _IO_CURRENTLY_PUTTING 0x0800
  85 #define _IO_IS_APPENDING      0x1000
  86 #define _IO_IS_FILEBUF        0x2000
  87                            /* 0x4000  No longer used, reserved for compat.  */
  88 #define _IO_USER_LOCK         0x8000
  89
  90 /* Bits for the _flags2 field.  */
  91 #define _IO_FLAGS2_MMAP 1
  92 #define _IO_FLAGS2_NOTCANCEL 2
  93 #define _IO_FLAGS2_USER_WBUF 8
  94 #define _IO_FLAGS2_NOCLOSE 32
  95 #define _IO_FLAGS2_CLOEXEC 64
  96 #define _IO_FLAGS2_NEED_LOCK 128
  97
  98 /* _IO_pos_BAD is an off64_t value indicating error, unknown, or EOF.  */
  99 #define _IO_pos_BAD ((off64_t) -1)
 100
 101 /* _IO_pos_adjust adjusts an off64_t by some number of bytes.  */
 102 #define _IO_pos_adjust(pos, delta) ((pos) += (delta))
 103
 104 /* _IO_pos_0 is an off64_t value indicating beginning of file.  */
 105 #define _IO_pos_0 ((off64_t) 0)
 106
 107 struct _IO_jump_t;
 108
 109 /* A streammarker remembers a position in a buffer. */
 110 struct _IO_marker {
 111   struct _IO_marker *_next;
 112   FILE *_sbuf;
 113   /* If _pos >= 0
 114  it points to _buf->Gbase()+_pos. FIXME comment */
 115   /* if _pos < 0, it points to _buf->eBptr()+_pos. FIXME comment */
 116   int _pos;
 117 };
 118
 119 /* This is the structure from the libstdc++ codecvt class.  */
 120 enum __codecvt_result
 121 {
 122   __codecvt_ok,
 123   __codecvt_partial,
 124   __codecvt_error,
 125   __codecvt_noconv
 126 };
 127
 128 /* The order of the elements in the following struct must match the order
 129    of the virtual functions in the libstdc++ codecvt class.  */
 130 struct _IO_codecvt
 131 {
 132   void (*__codecvt_destr) (struct _IO_codecvt *);
 133   enum __codecvt_result (*__codecvt_do_out) (struct _IO_codecvt *,
 134                                              __mbstate_t *,
 135                                              const wchar_t *,
 136                                              const wchar_t *,
 137                                              const wchar_t **, char *,
 138                                              char *, char **);
 139   enum __codecvt_result (*__codecvt_do_unshift) (struct _IO_codecvt *,
 140                                                  __mbstate_t *, char *,
 141                                                  char *, char **);
 142   enum __codecvt_result (*__codecvt_do_in) (struct _IO_codecvt *,
 143                                             __mbstate_t *,
 144                                             const char *, const char *,
 145                                             const char **, wchar_t *,
 146                                             wchar_t *, wchar_t **);
 147   int (*__codecvt_do_encoding) (struct _IO_codecvt *);
 148   int (*__codecvt_do_always_noconv) (struct _IO_codecvt *);
 149   int (*__codecvt_do_length) (struct _IO_codecvt *, __mbstate_t *,
 150                               const char *, const char *, size_t);
 151   int (*__codecvt_do_max_length) (struct _IO_codecvt *);
 152
 153   _IO_iconv_t __cd_in;
 154   _IO_iconv_t __cd_out;
 155 };
 156
 157 /* Extra data for wide character streams.  */
 158 struct _IO_wide_data
 159 {
 160   wchar_t *_IO_read_ptr;        /* Current read pointer */
 161   wchar_t *_IO_read_end;        /* End of get area. */
 162   wchar_t *_IO_read_base;       /* Start of putback+get area. */
 163   wchar_t *_IO_write_base;      /* Start of put area. */
 164   wchar_t *_IO_write_ptr;       /* Current put pointer. */
 165   wchar_t *_IO_write_end;       /* End of put area. */
 166   wchar_t *_IO_buf_base;        /* Start of reserve area. */
 167   wchar_t *_IO_buf_end;         /* End of reserve area. */
 168   /* The following fields are used to support backing up and undo. */
 169   wchar_t *_IO_save_base;       /* Pointer to start of non-current get area. */
 170   wchar_t *_IO_backup_base;     /* Pointer to first valid character of
 171                                    backup area */
 172   wchar_t *_IO_save_end;        /* Pointer to end of non-current get area. */
 173
 174   __mbstate_t _IO_state;
 175   __mbstate_t _IO_last_state;
 176   struct _IO_codecvt _codecvt;
 177
 178   wchar_t _shortbuf[1];
 179
 180   const struct _IO_jump_t *_wide_vtable;
 181 };
 182
 183 struct _IO_FILE_plus;
 184
 185 extern struct _IO_FILE_plus _IO_2_1_stdin_;
 186 extern struct _IO_FILE_plus _IO_2_1_stdout_;
 187 extern struct _IO_FILE_plus _IO_2_1_stderr_;
 188
 189 struct _IO_cookie_file;
 190
 191 /* Initialize one of those.  */
 192 extern void _IO_cookie_init (struct _IO_cookie_file *__cfile, int __read_write,
 193                              void *__cookie, cookie_io_functions_t __fns);
 194
 195 extern int __underflow (FILE *);
 196 extern wint_t __wunderflow (FILE *);
 197 extern wint_t __wuflow (FILE *);
 198 extern wint_t __woverflow (FILE *, wint_t);
 199
 200 #define _IO_getc_unlocked(_fp) __getc_unlocked_body (_fp)
 201 #define _IO_peekc_unlocked(_fp)                                         \
 202   (__glibc_unlikely ((_fp)->_IO_read_ptr >= (_fp)->_IO_read_end)        \
 203    && __underflow (_fp) == EOF                                          \
 204    ? EOF                                                                \
 205    : *(unsigned char *) (_fp)->_IO_read_ptr)
 206 #define _IO_putc_unlocked(_ch, _fp) __putc_unlocked_body (_ch, _fp)
 207
 208 # define _IO_getwc_unlocked(_fp)                                        \
 209   (__glibc_unlikely ((_fp)->_wide_data == NULL                          \
 210                      || ((_fp)->_wide_data->_IO_read_ptr                \
 211                          >= (_fp)->_wide_data->_IO_read_end))           \
 212    ? __wuflow (_fp) : (wint_t) *(_fp)->_wide_data->_IO_read_ptr++)
 213 # define _IO_putwc_unlocked(_wch, _fp)                                  \
 214   (__glibc_unlikely ((_fp)->_wide_data == NULL                          \
 215                      || ((_fp)->_wide_data->_IO_write_ptr               \
 216                          >= (_fp)->_wide_data->_IO_write_end))          \
 217    ? __woverflow (_fp, _wch)                                            \
 218    : (wint_t) (*(_fp)->_wide_data->_IO_write_ptr++ = (_wch)))
 219
 220 #define _IO_feof_unlocked(_fp) __feof_unlocked_body (_fp)
 221 #define _IO_ferror_unlocked(_fp) __ferror_unlocked_body (_fp)
 222
 223 extern int _IO_getc (FILE *__fp);
 224 extern int _IO_putc (int __c, FILE *__fp);
 225 extern int _IO_feof (FILE *__fp) __THROW;
 226 extern int _IO_ferror (FILE *__fp) __THROW;
 227
 228 extern int _IO_peekc_locked (FILE *__fp);
 229
 230 /* This one is for Emacs. */
 231 #define _IO_PENDING_OUTPUT_COUNT(_fp)   \
 232         ((_fp)->_IO_write_ptr - (_fp)->_IO_write_base)
 233
 234 extern void _IO_flockfile (FILE *) __THROW;
 235 extern void _IO_funlockfile (FILE *) __THROW;
 236 extern int _IO_ftrylockfile (FILE *) __THROW;
 237
 238 #define _IO_peekc(_fp) _IO_peekc_unlocked (_fp)
 239 #define _IO_flockfile(_fp) /**/
 240 #define _IO_funlockfile(_fp) ((void) 0)
 241 #define _IO_ftrylockfile(_fp) /**/
 242 #ifndef _IO_cleanup_region_start
 243 #define _IO_cleanup_region_start(_fct, _fp) /**/
 244 #endif
 245 #ifndef _IO_cleanup_region_end
 246 #define _IO_cleanup_region_end(_Doit) /**/
 247 #endif
 248
 249 #define _IO_need_lock(_fp) \
 250   (((_fp)->_flags2 & _IO_FLAGS2_NEED_LOCK) != 0)
 251
 252 extern int _IO_vfscanf (FILE * __restrict, const char * __restrict,
 253                         __gnuc_va_list, int *__restrict);
 254 extern __ssize_t _IO_padn (FILE *, int, __ssize_t);
 255 extern size_t _IO_sgetn (FILE *, void *, size_t);
 256
 257 extern off64_t _IO_seekoff (FILE *, off64_t, int, int);
 258 extern off64_t _IO_seekpos (FILE *, off64_t, int);
 259
 260 extern void _IO_free_backup_area (FILE *) __THROW;
 261
 262
 263 extern wint_t _IO_getwc (FILE *__fp);
 264 extern wint_t _IO_putwc (wchar_t __wc, FILE *__fp);
 265 extern int _IO_fwide (FILE *__fp, int __mode) __THROW;
 266
 267 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
 268 #  define _IO_fwide_maybe_incompatible \
 269   (__glibc_unlikely (&_IO_stdin_used == NULL))
 270 extern const int _IO_stdin_used;
 271 weak_extern (_IO_stdin_used);
 272 #else
 273 # define _IO_fwide_maybe_incompatible (0)
 274 #endif
 275
 276 /* A special optimized version of the function above.  It optimizes the
 277    case of initializing an unoriented byte stream.  */
 278 #define _IO_fwide(__fp, __mode) \
 279   ({ int __result = (__mode);                                                 \
 280      if (__result < 0 && ! _IO_fwide_maybe_incompatible)                      \
 281        {                                                                      \
 282          if ((__fp)->_mode == 0)                                              \
 283            /* We know that all we have to do is to set the flag.  */          \
 284            (__fp)->_mode = -1;                                                \
 285          __result = (__fp)->_mode;                                            \
 286        }                                                                      \
 287      else if (__builtin_constant_p (__mode) && (__mode) == 0)                 \
 288        __result = _IO_fwide_maybe_incompatible ? -1 : (__fp)->_mode;          \
 289      else                                                                     \
 290        __result = _IO_fwide (__fp, __result);                                 \
 291      __result; })
 292
 293 extern int _IO_vfwscanf (FILE * __restrict, const wchar_t * __restrict,
 294                          __gnuc_va_list, int *__restrict);
 295 extern __ssize_t _IO_wpadn (FILE *, wint_t, __ssize_t);
 296 extern void _IO_free_wbackup_area (FILE *) __THROW;
 297
 298 #ifdef __LDBL_COMPAT
 299 __LDBL_REDIR_DECL (_IO_vfscanf)
 300 #endif
 301
 302 libc_hidden_proto (__overflow)
 303 libc_hidden_proto (__underflow)
 304 libc_hidden_proto (__uflow)
 305 libc_hidden_proto (__woverflow)
 306 libc_hidden_proto (__wunderflow)
 307 libc_hidden_proto (__wuflow)
 308 libc_hidden_proto (_IO_free_backup_area)
 309 libc_hidden_proto (_IO_free_wbackup_area)
 310 libc_hidden_proto (_IO_padn)
 311 libc_hidden_proto (_IO_putc)
 312 libc_hidden_proto (_IO_sgetn)
 313
 314 #ifdef _IO_MTSAFE_IO
 315 # undef _IO_peekc
 316 # undef _IO_flockfile
 317 # undef _IO_funlockfile
 318 # undef _IO_ftrylockfile
 319
 320 # define _IO_peekc(_fp) _IO_peekc_locked (_fp)
 321 # if _IO_lock_inexpensive
 322 #  define _IO_flockfile(_fp) \
 323   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_lock (*(_fp)->_lock)
 324 #  define _IO_funlockfile(_fp) \
 325   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_unlock (*(_fp)->_lock)
 326 # else
 327 #  define _IO_flockfile(_fp) \
 328   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_flockfile (_fp)
 329 #  define _IO_funlockfile(_fp) \
 330   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_funlockfile (_fp)
 331 # endif
 332 #endif /* _IO_MTSAFE_IO */
 333
 334 #endif /* _LIBIO_H */