libio/libio.h

   1 /* Copyright (C) 1991-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library 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 GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.
  17
  18    As a special exception, if you link the code in this file with
  19    files compiled with a GNU compiler to produce an executable,
  20    that does not cause the resulting executable to be covered by
  21    the GNU Lesser General Public License.  This exception does not
  22    however invalidate any other reasons why the executable file
  23    might be covered by the GNU Lesser General Public License.
  24    This exception applies to code released by its copyright holders
  25    in files containing the exception.  */
  26
  27 #ifndef _LIBIO_H
  28 #define _LIBIO_H 1
  29
  30 #ifndef _LIBC
  31 # error "libio.h should only be included when building glibc itself"
  32 #endif
  33 #ifdef _ISOMAC
  34 # error "libio.h should not be included under _ISOMAC"
  35 #endif
  36
  37 #include <stdio.h>
  38
  39 #if defined _IO_MTSAFE_IO && !defined _IO_lock_t_defined
  40 # error "Someone forgot to include stdio-lock.h"
  41 #endif
  42
  43 #define __need_wchar_t
  44 #include <stddef.h>
  45
  46 #include <bits/types/__mbstate_t.h>
  47 #include <bits/types/wint_t.h>
  48 #include <gconv.h>
  49
  50 typedef struct
  51 {
  52   struct __gconv_step *step;
  53   struct __gconv_step_data step_data;
  54 } _IO_iconv_t;
  55
  56 #include <shlib-compat.h>
  57
  58 /* _IO_seekoff modes */
  59 #define _IOS_INPUT      1
  60 #define _IOS_OUTPUT     2
  61
  62 /* Magic number and bits for the _flags field.  The magic number is
  63    mostly vestigial, but preserved for compatibility.  It occupies the
  64    high 16 bits of _flags; the low 16 bits are actual flag bits.  */
  65
  66 #define _IO_MAGIC         0xFBAD0000 /* Magic number */
  67 #define _IO_MAGIC_MASK    0xFFFF0000
  68 #define _IO_USER_BUF          0x0001 /* Don't deallocate buffer on close. */
  69 #define _IO_UNBUFFERED        0x0002
  70 #define _IO_NO_READS          0x0004 /* Reading not allowed.  */
  71 #define _IO_NO_WRITES         0x0008 /* Writing not allowed.  */
  72 #define _IO_EOF_SEEN          0x0010
  73 #define _IO_ERR_SEEN          0x0020
  74 #define _IO_DELETE_DONT_CLOSE 0x0040 /* Don't call close(_fileno) on close.  */
  75 #define _IO_LINKED            0x0080 /* In the list of all open files.  */
  76 #define _IO_IN_BACKUP         0x0100
  77 #define _IO_LINE_BUF          0x0200
  78 #define _IO_TIED_PUT_GET      0x0400 /* Put and get pointer move in unison.  */
  79 #define _IO_CURRENTLY_PUTTING 0x0800
  80 #define _IO_IS_APPENDING      0x1000
  81 #define _IO_IS_FILEBUF        0x2000
  82                            /* 0x4000  No longer used, reserved for compat.  */
  83 #define _IO_USER_LOCK         0x8000
  84
  85 /* Bits for the _flags2 field.  */
  86 #define _IO_FLAGS2_MMAP 1
  87 #define _IO_FLAGS2_NOTCANCEL 2
  88 #define _IO_FLAGS2_USER_WBUF 8
  89 #define _IO_FLAGS2_NOCLOSE 32
  90 #define _IO_FLAGS2_CLOEXEC 64
  91 #define _IO_FLAGS2_NEED_LOCK 128
  92
  93 /* _IO_pos_BAD is an off64_t value indicating error, unknown, or EOF.  */
  94 #define _IO_pos_BAD ((off64_t) -1)
  95
  96 /* _IO_pos_adjust adjusts an off64_t by some number of bytes.  */
  97 #define _IO_pos_adjust(pos, delta) ((pos) += (delta))
  98
  99 /* _IO_pos_0 is an off64_t value indicating beginning of file.  */
 100 #define _IO_pos_0 ((off64_t) 0)
 101
 102 struct _IO_jump_t;
 103
 104 /* A streammarker remembers a position in a buffer. */
 105 struct _IO_marker {
 106   struct _IO_marker *_next;
 107   FILE *_sbuf;
 108   /* If _pos >= 0
 109  it points to _buf->Gbase()+_pos. FIXME comment */
 110   /* if _pos < 0, it points to _buf->eBptr()+_pos. FIXME comment */
 111   int _pos;
 112 };
 113
 114 struct _IO_codecvt
 115 {
 116   _IO_iconv_t __cd_in;
 117   _IO_iconv_t __cd_out;
 118 };
 119
 120 /* Extra data for wide character streams.  */
 121 struct _IO_wide_data
 122 {
 123   wchar_t *_IO_read_ptr;        /* Current read pointer */
 124   wchar_t *_IO_read_end;        /* End of get area. */
 125   wchar_t *_IO_read_base;       /* Start of putback+get area. */
 126   wchar_t *_IO_write_base;      /* Start of put area. */
 127   wchar_t *_IO_write_ptr;       /* Current put pointer. */
 128   wchar_t *_IO_write_end;       /* End of put area. */
 129   wchar_t *_IO_buf_base;        /* Start of reserve area. */
 130   wchar_t *_IO_buf_end;         /* End of reserve area. */
 131   /* The following fields are used to support backing up and undo. */
 132   wchar_t *_IO_save_base;       /* Pointer to start of non-current get area. */
 133   wchar_t *_IO_backup_base;     /* Pointer to first valid character of
 134                                    backup area */
 135   wchar_t *_IO_save_end;        /* Pointer to end of non-current get area. */
 136
 137   __mbstate_t _IO_state;
 138   __mbstate_t _IO_last_state;
 139   struct _IO_codecvt _codecvt;
 140
 141   wchar_t _shortbuf[1];
 142
 143   const struct _IO_jump_t *_wide_vtable;
 144 };
 145
 146 struct _IO_FILE_plus;
 147
 148 extern struct _IO_FILE_plus _IO_2_1_stdin_;
 149 extern struct _IO_FILE_plus _IO_2_1_stdout_;
 150 extern struct _IO_FILE_plus _IO_2_1_stderr_;
 151
 152 struct _IO_cookie_file;
 153
 154 /* Initialize one of those.  */
 155 extern void _IO_cookie_init (struct _IO_cookie_file *__cfile, int __read_write,
 156                              void *__cookie, cookie_io_functions_t __fns);
 157
 158 extern int __underflow (FILE *);
 159 extern wint_t __wunderflow (FILE *);
 160 extern wint_t __wuflow (FILE *);
 161 extern wint_t __woverflow (FILE *, wint_t);
 162
 163 #define _IO_getc_unlocked(_fp) __getc_unlocked_body (_fp)
 164 #define _IO_peekc_unlocked(_fp)                                         \
 165   (__glibc_unlikely ((_fp)->_IO_read_ptr >= (_fp)->_IO_read_end)        \
 166    && __underflow (_fp) == EOF                                          \
 167    ? EOF                                                                \
 168    : *(unsigned char *) (_fp)->_IO_read_ptr)
 169 #define _IO_putc_unlocked(_ch, _fp) __putc_unlocked_body (_ch, _fp)
 170
 171 # define _IO_getwc_unlocked(_fp)                                        \
 172   (__glibc_unlikely ((_fp)->_wide_data == NULL                          \
 173                      || ((_fp)->_wide_data->_IO_read_ptr                \
 174                          >= (_fp)->_wide_data->_IO_read_end))           \
 175    ? __wuflow (_fp) : (wint_t) *(_fp)->_wide_data->_IO_read_ptr++)
 176 # define _IO_putwc_unlocked(_wch, _fp)                                  \
 177   (__glibc_unlikely ((_fp)->_wide_data == NULL                          \
 178                      || ((_fp)->_wide_data->_IO_write_ptr               \
 179                          >= (_fp)->_wide_data->_IO_write_end))          \
 180    ? __woverflow (_fp, _wch)                                            \
 181    : (wint_t) (*(_fp)->_wide_data->_IO_write_ptr++ = (_wch)))
 182
 183 #define _IO_feof_unlocked(_fp) __feof_unlocked_body (_fp)
 184 #define _IO_ferror_unlocked(_fp) __ferror_unlocked_body (_fp)
 185
 186 extern int _IO_getc (FILE *__fp);
 187 extern int _IO_putc (int __c, FILE *__fp);
 188 extern int _IO_feof (FILE *__fp) __THROW;
 189 extern int _IO_ferror (FILE *__fp) __THROW;
 190
 191 extern int _IO_peekc_locked (FILE *__fp);
 192
 193 /* This one is for Emacs. */
 194 #define _IO_PENDING_OUTPUT_COUNT(_fp)   \
 195         ((_fp)->_IO_write_ptr - (_fp)->_IO_write_base)
 196
 197 extern void _IO_flockfile (FILE *) __THROW;
 198 extern void _IO_funlockfile (FILE *) __THROW;
 199 extern int _IO_ftrylockfile (FILE *) __THROW;
 200
 201 #define _IO_peekc(_fp) _IO_peekc_unlocked (_fp)
 202 #define _IO_flockfile(_fp) /**/
 203 #define _IO_funlockfile(_fp) ((void) 0)
 204 #define _IO_ftrylockfile(_fp) /**/
 205 #ifndef _IO_cleanup_region_start
 206 #define _IO_cleanup_region_start(_fct, _fp) /**/
 207 #endif
 208 #ifndef _IO_cleanup_region_end
 209 #define _IO_cleanup_region_end(_Doit) /**/
 210 #endif
 211
 212 #define _IO_need_lock(_fp) \
 213   (((_fp)->_flags2 & _IO_FLAGS2_NEED_LOCK) != 0)
 214
 215 extern int _IO_vfscanf (FILE * __restrict, const char * __restrict,
 216                         __gnuc_va_list, int *__restrict);
 217 extern __ssize_t _IO_padn (FILE *, int, __ssize_t);
 218 extern size_t _IO_sgetn (FILE *, void *, size_t);
 219
 220 extern off64_t _IO_seekoff (FILE *, off64_t, int, int);
 221 extern off64_t _IO_seekpos (FILE *, off64_t, int);
 222
 223 extern void _IO_free_backup_area (FILE *) __THROW;
 224
 225
 226 extern wint_t _IO_getwc (FILE *__fp);
 227 extern wint_t _IO_putwc (wchar_t __wc, FILE *__fp);
 228 extern int _IO_fwide (FILE *__fp, int __mode) __THROW;
 229
 230 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
 231 #  define _IO_fwide_maybe_incompatible \
 232   (__glibc_unlikely (&_IO_stdin_used == NULL))
 233 extern const int _IO_stdin_used;
 234 weak_extern (_IO_stdin_used);
 235 #else
 236 # define _IO_fwide_maybe_incompatible (0)
 237 #endif
 238
 239 /* A special optimized version of the function above.  It optimizes the
 240    case of initializing an unoriented byte stream.  */
 241 #define _IO_fwide(__fp, __mode) \
 242   ({ int __result = (__mode);                                                 \
 243      if (__result < 0 && ! _IO_fwide_maybe_incompatible)                      \
 244        {                                                                      \
 245          if ((__fp)->_mode == 0)                                              \
 246            /* We know that all we have to do is to set the flag.  */          \
 247            (__fp)->_mode = -1;                                                \
 248          __result = (__fp)->_mode;                                            \
 249        }                                                                      \
 250      else if (__builtin_constant_p (__mode) && (__mode) == 0)                 \
 251        __result = _IO_fwide_maybe_incompatible ? -1 : (__fp)->_mode;          \
 252      else                                                                     \
 253        __result = _IO_fwide (__fp, __result);                                 \
 254      __result; })
 255
 256 extern __ssize_t _IO_wpadn (FILE *, wint_t, __ssize_t);
 257 extern void _IO_free_wbackup_area (FILE *) __THROW;
 258
 259 #ifdef __LDBL_COMPAT
 260 __LDBL_REDIR_DECL (_IO_vfscanf)
 261 #endif
 262
 263 libc_hidden_proto (__overflow)
 264 libc_hidden_proto (__underflow)
 265 libc_hidden_proto (__uflow)
 266 libc_hidden_proto (__woverflow)
 267 libc_hidden_proto (__wunderflow)
 268 libc_hidden_proto (__wuflow)
 269 libc_hidden_proto (_IO_free_backup_area)
 270 libc_hidden_proto (_IO_free_wbackup_area)
 271 libc_hidden_proto (_IO_padn)
 272 libc_hidden_proto (_IO_putc)
 273 libc_hidden_proto (_IO_sgetn)
 274
 275 #ifdef _IO_MTSAFE_IO
 276 # undef _IO_peekc
 277 # undef _IO_flockfile
 278 # undef _IO_funlockfile
 279 # undef _IO_ftrylockfile
 280
 281 # define _IO_peekc(_fp) _IO_peekc_locked (_fp)
 282 # define _IO_flockfile(_fp) \
 283   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_lock (*(_fp)->_lock)
 284 # define _IO_funlockfile(_fp) \
 285   if (((_fp)->_flags & _IO_USER_LOCK) == 0) _IO_lock_unlock (*(_fp)->_lock)
 286 #endif /* _IO_MTSAFE_IO */
 287
 288 #endif /* _LIBIO_H */