libio/libioP.h

   1 /*
   2 Copyright (C) 1993 Free Software Foundation
   3
   4 This file is part of the GNU IO Library.  This library is free
   5 software; you can redistribute it and/or modify it under the
   6 terms of the GNU General Public License as published by the
   7 Free Software Foundation; either version 2, or (at your option)
   8 any later version.
   9
  10 This 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
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this library; see the file COPYING.  If not, write to the Free
  17 Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18
  19 As a special exception, if you link this library with files
  20 compiled with a GNU compiler to produce an executable, this does not cause
  21 the resulting executable to be covered by the GNU General Public License.
  22 This exception does not however invalidate any other reasons why
  23 the executable file might be covered by the GNU General Public License. */
  24
  25 #include <errno.h>
  26 #ifndef errno
  27 extern int errno;
  28 #endif
  29
  30 #include "iolibio.h"
  31
  32 #if defined (__STDC__) || defined (_AIX) || (defined (__mips) && defined (_SYSTYPE_SVR4)) || defined(__cplusplus)
  33 /* All known AIX compilers implement these things (but don't always
  34    define __STDC__).  The RISC/OS MIPS compiler defines these things
  35    in SVR4 mode, but does not define __STDC__.  */
  36
  37 #define AND             ,
  38 #define DEFUN(name, arglist, args)      name(args)
  39 #define DEFUN_VOID(name)                name(void)
  40
  41 #else   /* Not ANSI C.  */
  42
  43 #define AND             ;
  44 #ifndef const /* some systems define it in header files for non-ansi mode */
  45 #define const
  46 #endif
  47 #define DEFUN(name, arglist, args)      name arglist args;
  48 #define DEFUN_VOID(name)                name()
  49 #endif  /* ANSI C.  */
  50
  51 #ifdef __cplusplus
  52 extern "C" {
  53 #endif
  54
  55 #define _IO_seek_set 0
  56 #define _IO_seek_cur 1
  57 #define _IO_seek_end 2
  58
  59 /* THE JUMPTABLE FUNCTIONS.
  60
  61  * The _IO_FILE type is used to implement the FILE type in GNU libc,
  62  * as well as the streambuf class in GNU iostreams for C++.
  63  * These are all the same, just used differently.
  64  * An _IO_FILE (or FILE) object is allows followed by a pointer to
  65  * a jump table (of pointers to functions).  The pointer is accessed
  66  * with the _IO_JUMPS macro.  The jump table has a eccentric format,
  67  * so as to be compatible with the layout of a C++ virtual function table.
  68  * (as implemented by g++).  When a pointer to a steambuf object is
  69  * coerced to an (_IO_FILE*), then _IO_JUMPS on the result just
  70  * happens to point to the virtual function table of the streambuf.
  71  * Thus the _IO_JUMPS function table used for C stdio/libio does
  72  * double duty as the virtual functiuon table for C++ streambuf.
  73  *
  74  * The entries in the _IO_JUMPS function table (and hence also the
  75  * virtual functions of a streambuf) are described below.
  76  * The first parameter of each function entry is the _IO_FILE/streambuf
  77  * object being acted on (i.e. the 'this' parameter).
  78  */
  79
  80 #define _IO_JUMPS(THIS) ((struct _IO_FILE_plus*)(THIS))->vtable
  81 #ifdef _G_USING_THUNKS
  82 #define JUMP_FIELD(TYPE, NAME) TYPE NAME
  83 #define JUMP0(FUNC, THIS) _IO_JUMPS(THIS)->FUNC(THIS)
  84 #define JUMP1(FUNC, THIS, X1) _IO_JUMPS(THIS)->FUNC(THIS, X1)
  85 #define JUMP2(FUNC, THIS, X1, X2) _IO_JUMPS(THIS)->FUNC(THIS, X1, X2)
  86 #define JUMP3(FUNC, THIS, X1,X2,X3) _IO_JUMPS(THIS)->FUNC(THIS, X1,X2, X3)
  87 #define JUMP_INIT(NAME, VALUE) VALUE
  88 #define JUMP_INIT_DUMMY JUMP_INIT(dummy, 0), JUMP_INIT(dummy2, 0)
  89 #else
  90 /* These macros will change when we re-implement vtables to use "thunks"! */
  91 #define JUMP_FIELD(TYPE, NAME) struct { short delta1, delta2; TYPE pfn; } NAME
  92 #define JUMP0(FUNC, THIS) _IO_JUMPS(THIS)->FUNC.pfn(THIS)
  93 #define JUMP1(FUNC, THIS, X1) _IO_JUMPS(THIS)->FUNC.pfn(THIS, X1)
  94 #define JUMP2(FUNC, THIS, X1, X2) _IO_JUMPS(THIS)->FUNC.pfn(THIS, X1, X2)
  95 #define JUMP3(FUNC, THIS, X1,X2,X3) _IO_JUMPS(THIS)->FUNC.pfn(THIS, X1,X2, X3)
  96 #define JUMP_INIT(NAME, VALUE) {0, 0, VALUE}
  97 #define JUMP_INIT_DUMMY JUMP_INIT(dummy, 0)
  98 #endif
  99
 100 /* The 'finish' function does any final cleaning up of an _IO_FILE object.
 101    It does not delete (free) it, but does everything else to finalize it/
 102    It matches the streambuf::~streambuf virtual destructor.  */
 103 typedef void (*_IO_finish_t) __P((_IO_FILE*)); /* finalize */
 104 #define _IO_FINISH(FP) JUMP0(__finish, FP)
 105
 106 /* The 'overflow' hook flushes the buffer.
 107    The second argument is a character, or EOF.
 108    It matches the streambuf::overflow virtual function. */
 109 typedef int (*_IO_overflow_t) __P((_IO_FILE*, int));
 110 #define _IO_OVERFLOW(FP, CH) JUMP1(__overflow, FP, CH)
 111
 112 /* The 'underflow' hook tries to fills the get buffer.
 113    It returns the next character (as an unsigned char) or EOF.  The next
 114    character remains in the get buffer, and the get postion is not changed.
 115    It matches the streambuf::underflow virtual function. */
 116 typedef int (*_IO_underflow_t) __P((_IO_FILE*));
 117 #define _IO_UNDERFLOW(FP) JUMP0(__underflow, FP)
 118
 119 /* The 'uflow' hook returns the next character in the input stream
 120    (cast to unsigned char), and increments the read position;
 121    EOF is returned on failure.
 122    It matches the streambuf::uflow virtual function, which is not in the
 123    cfront implementation, but was added to C++ by the ANSI/ISO committee. */
 124 #define _IO_UFLOW(FP) JUMP0(__uflow, FP)
 125
 126 /* The 'pbackfail' hook handles backing up.
 127    It matches the streambuf::pbackfail virtual function. */
 128 typedef int (*_IO_pbackfail_t) __P((_IO_FILE*, int));
 129 #define _IO_PBACKFAIL(FP, CH) JUMP1(__pbackfail, FP, CH)
 130
 131 /* The 'xsputn' hook writes upto N characters from buffer DATA.
 132    Returns the number of character actually written.
 133    It matches the streambuf::xsputn virtual function. */
 134 typedef _IO_size_t (*_IO_xsputn_t)
 135   __P((_IO_FILE *FP, const void *DATA, _IO_size_t N));
 136 #define _IO_XSPUTN(FP, DATA, N) JUMP2(__xsputn, FP, DATA, N)
 137
 138 /* The 'xsgetn' hook reads upto N characters into buffer DATA.
 139    Returns the number of character actually read.
 140    It matches the streambuf::xsgetn virtual function. */
 141 typedef _IO_size_t (*_IO_xsgetn_t) __P((_IO_FILE*FP, void*DATA, _IO_size_t N));
 142 #define _IO_XSGETN(FP, DATA, N) JUMP2(__xsgetn, FP, DATA, N)
 143
 144 /* The 'seekoff' hook moves the stream position to a new position
 145    relative to the start of the file (if DIR==0), the current position
 146    (MODE==1), or the end of the file (MODE==2).
 147    It matches the streambuf::seekoff virtual function.
 148    It is also used for the ANSI fseek function. */
 149 typedef _IO_fpos_t (*_IO_seekoff_t)
 150   __P((_IO_FILE* FP, _IO_off_t OFF, int DIR, int MODE));
 151 #define _IO_SEEKOFF(FP, OFF, DIR, MODE) JUMP3(__seekoff, FP, OFF, DIR, MODE)
 152
 153 /* The 'seekpos' hook also moves the stream position,
 154    but to an absolute position given by a fpos_t (seekpos).
 155    It matches the streambuf::seekpos virtual function.
 156    It is also used for the ANSI fgetpos and fsetpos functions.  */
 157 /* The _IO_seek_cur and _IO_seek_end options are not allowed. */
 158 typedef _IO_fpos_t (*_IO_seekpos_t) __P((_IO_FILE*, _IO_fpos_t, int));
 159 #define _IO_SEEKPOS(FP, POS, FLAGS) JUMP2(__seekpos, FP, POS, FLAGS)
 160
 161 /* The 'setbuf' hook gives a buffer to the file.
 162    It matches the streambuf::setbuf virtual function. */
 163 typedef _IO_FILE* (*_IO_setbuf_t) __P((_IO_FILE*, char *, _IO_ssize_t));
 164 #define _IO_SETBUF(FP, BUFFER, LENGTH) JUMP2(__setbuf, FP, BUFFER, LENGTH)
 165
 166 /* The 'sync' hook attempts to synchronize the internal data structures
 167    of the file with the external state.
 168    It matches the streambuf::sync virtual function. */
 169 typedef int (*_IO_sync_t) __P((_IO_FILE*));
 170 #define _IO_SYNC(FP) JUMP0(__sync, FP)
 171
 172 /* The 'doallocate' hook is used to tell the file to allocate a buffer.
 173    It matches the streambuf::doallocate virtual function, which is not
 174    in the ANSI/ISO C++ standard, but is part traditional implementations. */
 175 typedef int (*_IO_doallocate_t) __P((_IO_FILE*));
 176 #define _IO_DOALLOCATE(FP) JUMP0(__doallocate, FP)
 177
 178 /* The following four hooks (sysread, syswrite, sysclose, sysseek, and
 179    sysstat) are low-level hooks specific to this implementation.
 180    There is no correspondance in the ANSI/ISO C++ standard library.
 181    The hooks basically correspond to the Unix system functions
 182    (read, write, close, lseek, and stat) except that a _IO_FILE*
 183    parameter is used instead of a integer file descriptor;  the default
 184    implementation used for normal files just calls those functions.
 185    The advantage of overriding these functions instead of the higher-level
 186    ones (underflow, overflow etc) is that you can leave all the buffering
 187    higher-level functions.  */
 188
 189 /* The 'sysread' hook is used to read data from the external file into
 190    an existing buffer.  It generalizes the Unix read(2) function.
 191    It matches the streambuf::sys_read virtual function, which is
 192    specific to this implementaion. */
 193 typedef _IO_ssize_t (*_IO_read_t) __P((_IO_FILE*, void*, _IO_ssize_t));
 194 #define _IO_SYSREAD(FP, DATA, LEN) JUMP2(__read, FP, DATA, LEN)
 195
 196 /* The 'syswrite' hook is used to write data from an existing buffer
 197    to an external file.  It generalizes the Unix write(2) function.
 198    It matches the streambuf::sys_write virtual function, which is
 199    specific to this implementaion. */
 200 typedef _IO_ssize_t (*_IO_write_t) __P((_IO_FILE*,const void*,_IO_ssize_t));
 201 #define _IO_SYSWRITE(FP, DATA, LEN) JUMP2(__write, FP, DATA, LEN)
 202
 203 /* The 'sysseek' hook is used to re-position an external file.
 204    It generalizes the Unix lseek(2) function.
 205    It matches the streambuf::sys_seek virtual function, which is
 206    specific to this implementaion. */
 207 typedef _IO_fpos_t (*_IO_seek_t) __P((_IO_FILE*, _IO_off_t, int));
 208 #define _IO_SYSSEEK(FP, OFFSET, MODE) JUMP2(__seek, FP, OFFSET, MODE)
 209
 210 /* The 'sysclose' hook is used to finalize (close, finish up) an
 211    external file.  It generalizes the Unix close(2) function.
 212    It matches the streambuf::sys_close virtual function, which is
 213    specific to this implementation. */
 214 typedef int (*_IO_close_t) __P((_IO_FILE*)); /* finalize */
 215 #define _IO_SYSCLOSE(FP) JUMP0(__close, FP)
 216
 217 /* The 'sysstat' hook is used to get information about an external file
 218    into a struct stat buffer.  It generalizes the Unix fstat(2) call.
 219    It matches the streambuf::sys_stat virtual function, which is
 220    specific to this implementaion. */
 221 typedef int (*_IO_stat_t) __P((_IO_FILE*, void*));
 222 #define _IO_SYSSTAT(FP, BUF) JUMP1(__stat, FP, BUF)
 223
 224
 225 #define _IO_CHAR_TYPE char /* unsigned char ? */
 226 #define _IO_INT_TYPE int
 227
 228 struct _IO_jump_t {
 229     JUMP_FIELD(_G_size_t, __dummy);
 230 #ifdef _G_USING_THUNKS
 231     JUMP_FIELD(_G_size_t, __dummy2);
 232 #endif
 233     JUMP_FIELD(_IO_finish_t, __finish);
 234     JUMP_FIELD(_IO_overflow_t, __overflow);
 235     JUMP_FIELD(_IO_underflow_t, __underflow);
 236     JUMP_FIELD(_IO_underflow_t, __uflow);
 237     JUMP_FIELD(_IO_pbackfail_t, __pbackfail);
 238     /* showmany */
 239     JUMP_FIELD(_IO_xsputn_t, __xsputn);
 240     JUMP_FIELD(_IO_xsgetn_t, __xsgetn);
 241     JUMP_FIELD(_IO_seekoff_t, __seekoff);
 242     JUMP_FIELD(_IO_seekpos_t, __seekpos);
 243     JUMP_FIELD(_IO_setbuf_t, __setbuf);
 244     JUMP_FIELD(_IO_sync_t, __sync);
 245     JUMP_FIELD(_IO_doallocate_t, __doallocate);
 246     JUMP_FIELD(_IO_read_t, __read);
 247     JUMP_FIELD(_IO_write_t, __write);
 248     JUMP_FIELD(_IO_seek_t, __seek);
 249     JUMP_FIELD(_IO_close_t, __close);
 250     JUMP_FIELD(_IO_stat_t, __stat);
 251 #if 0
 252     get_column;
 253     set_column;
 254 #endif
 255 };
 256
 257 /* We always allocate an extra word following an _IO_FILE.
 258    This contains a pointer to the function jump table used.
 259    This is for compatibility with C++ streambuf; the word can
 260    be used to smash to a pointer to a virtual function table. */
 261
 262 struct _IO_FILE_plus {
 263   _IO_FILE file;
 264   const struct _IO_jump_t *vtable;
 265 };
 266
 267 /* Generic functions */
 268
 269 extern int _IO_switch_to_get_mode __P((_IO_FILE*));
 270 extern void _IO_init __P((_IO_FILE*, int));
 271 extern int _IO_sputbackc __P((_IO_FILE*, int));
 272 extern int _IO_sungetc __P((_IO_FILE*));
 273 extern void _IO_un_link __P((_IO_FILE*));
 274 extern void _IO_link_in __P((_IO_FILE *));
 275 extern void _IO_doallocbuf __P((_IO_FILE*));
 276 extern void _IO_unsave_markers __P((_IO_FILE*));
 277 extern void _IO_setb __P((_IO_FILE*, char*, char*, int));
 278 extern unsigned _IO_adjust_column __P((unsigned, const char *, int));
 279 #define _IO_sputn(__fp, __s, __n) _IO_XSPUTN(__fp, __s, __n)
 280
 281 /* Marker-related function. */
 282
 283 extern void _IO_init_marker __P((struct _IO_marker *, _IO_FILE *));
 284 extern void _IO_remove_marker __P((struct _IO_marker*));
 285 extern int _IO_marker_difference __P((struct _IO_marker *, struct _IO_marker *));
 286 extern int _IO_marker_delta __P((struct _IO_marker *));
 287 extern int _IO_seekmark __P((_IO_FILE *, struct _IO_marker *, int));
 288
 289 /* Default jumptable functions. */
 290
 291 extern int _IO_default_underflow __P((_IO_FILE*));
 292 extern int _IO_default_uflow __P((_IO_FILE*));
 293 extern int _IO_default_doallocate __P((_IO_FILE*));
 294 extern void _IO_default_finish __P((_IO_FILE *));
 295 extern int _IO_default_pbackfail __P((_IO_FILE*, int));
 296 extern _IO_FILE* _IO_default_setbuf __P((_IO_FILE *, char*, _IO_ssize_t));
 297 extern _IO_size_t _IO_default_xsputn __P((_IO_FILE *, const void*, _IO_size_t));
 298 extern _IO_size_t _IO_default_xsgetn __P((_IO_FILE *, void*, _IO_size_t));
 299 extern _IO_fpos_t _IO_default_seekoff __P((_IO_FILE*, _IO_off_t, int, int));
 300 extern _IO_fpos_t _IO_default_seekpos __P((_IO_FILE*, _IO_fpos_t, int));
 301 extern _IO_ssize_t _IO_default_write __P((_IO_FILE*,const void*,_IO_ssize_t));
 302 extern _IO_ssize_t _IO_default_read __P((_IO_FILE*, void*, _IO_ssize_t));
 303 extern int _IO_default_stat __P((_IO_FILE*, void*));
 304 extern _IO_fpos_t _IO_default_seek __P((_IO_FILE*, _IO_off_t, int));
 305 extern int _IO_default_sync __P((_IO_FILE*));
 306 #define _IO_default_close ((_IO_close_t)_IO_default_sync)
 307
 308 extern struct _IO_jump_t _IO_file_jumps;
 309 extern struct _IO_jump_t _IO_streambuf_jumps;
 310 extern struct _IO_jump_t _IO_proc_jumps;
 311 extern struct _IO_jump_t _IO_str_jumps;
 312 extern int _IO_do_write __P((_IO_FILE*, const char*, _IO_size_t));
 313 extern int _IO_flush_all __P((void));
 314 extern void _IO_cleanup __P((void));
 315 extern void _IO_flush_all_linebuffered __P((void));
 316
 317 #define _IO_do_flush(_f) \
 318   _IO_do_write(_f, (_f)->_IO_write_base, \
 319                (_f)->_IO_write_ptr-(_f)->_IO_write_base)
 320 #define _IO_in_put_mode(_fp) ((_fp)->_flags & _IO_CURRENTLY_PUTTING)
 321 #define _IO_mask_flags(fp, f, mask) \
 322        ((fp)->_flags = ((fp)->_flags & ~(mask)) | ((f) & (mask)))
 323 #define _IO_setg(fp, eb, g, eg)  ((fp)->_IO_read_base = (eb),\
 324         (fp)->_IO_read_ptr = (g), (fp)->_IO_read_end = (eg))
 325 #define _IO_setp(__fp, __p, __ep) \
 326        ((__fp)->_IO_write_base = (__fp)->_IO_write_ptr = __p, (__fp)->_IO_write_end = (__ep))
 327 #define _IO_have_backup(fp) ((fp)->_IO_save_base != NULL)
 328 #define _IO_in_backup(fp) ((fp)->_flags & _IO_IN_BACKUP)
 329 #define _IO_have_markers(fp) ((fp)->_markers != NULL)
 330 #define _IO_blen(fp) ((fp)->_IO_buf_end - (fp)->_IO_buf_base)
 331
 332 /* Jumptable functions for files. */
 333
 334 extern int _IO_file_doallocate __P((_IO_FILE*));
 335 extern _IO_FILE* _IO_file_setbuf __P((_IO_FILE *, char*, _IO_ssize_t));
 336 extern _IO_fpos_t _IO_file_seekoff __P((_IO_FILE*, _IO_off_t, int, int));
 337 extern _IO_size_t _IO_file_xsputn __P((_IO_FILE*,const void*,_IO_size_t));
 338 extern int _IO_file_stat __P((_IO_FILE*, void*));
 339 extern int _IO_file_close __P((_IO_FILE*));
 340 extern int _IO_file_underflow __P((_IO_FILE *));
 341 extern int _IO_file_overflow __P((_IO_FILE *, int));
 342 #define _IO_file_is_open(__fp) ((__fp)->_fileno >= 0)
 343 extern void _IO_file_init __P((_IO_FILE*));
 344 extern _IO_FILE* _IO_file_fopen __P((_IO_FILE*, const char*, const char*));
 345 extern _IO_ssize_t _IO_file_write __P((_IO_FILE*,const void*,_IO_ssize_t));
 346 extern _IO_ssize_t _IO_file_read __P((_IO_FILE*, void*, _IO_ssize_t));
 347 extern int _IO_file_sync __P((_IO_FILE*));
 348 extern int _IO_file_close_it __P((_IO_FILE*));
 349 extern _IO_fpos_t _IO_file_seek __P((_IO_FILE *, _IO_off_t, int));
 350 extern void _IO_file_finish __P((_IO_FILE*));
 351
 352 /* Other file functions. */
 353 extern _IO_FILE* _IO_file_attach __P((_IO_FILE *, int));
 354
 355 /* Jumptable functions for proc_files. */
 356 extern _IO_FILE* _IO_proc_open __P((_IO_FILE*, const char*, const char *));
 357 extern int _IO_proc_close __P((_IO_FILE*));
 358
 359 /* Jumptable functions for strfiles. */
 360 extern int _IO_str_underflow __P((_IO_FILE*));
 361 extern int _IO_str_overflow __P((_IO_FILE *, int));
 362 extern int _IO_str_pbackfail __P((_IO_FILE*, int));
 363 extern _IO_fpos_t _IO_str_seekoff __P((_IO_FILE*,_IO_off_t,int,int));
 364
 365 /* Other strfile functions */
 366 extern void _IO_str_init_static __P((_IO_FILE *, char*, int, char*));
 367 extern void _IO_str_init_readonly __P((_IO_FILE *, const char*, int));
 368 extern _IO_ssize_t _IO_str_count __P ((_IO_FILE*));
 369
 370 extern _IO_size_t _IO_getline __P((_IO_FILE*,char*,_IO_size_t,int,int));
 371 extern _IO_ssize_t _IO_getdelim __P((char**, _IO_size_t*, int, _IO_FILE*));
 372 extern double _IO_strtod __P((const char *, char **));
 373 extern char * _IO_dtoa __P((double __d, int __mode, int __ndigits,
 374                                 int *__decpt, int *__sign, char **__rve));
 375 extern int _IO_outfloat __P((double __value, _IO_FILE *__sb, int __type,
 376                                  int __width, int __precision, int __flags,
 377                                  int __sign_mode, int __fill));
 378
 379 extern _IO_FILE *_IO_list_all;
 380 extern void (*_IO_cleanup_registration_needed) __P ((void));
 381
 382 #ifndef EOF
 383 #define EOF (-1)
 384 #endif
 385 #ifndef NULL
 386 #ifdef __GNUG__
 387 #define NULL (__null)
 388 #else
 389 #if !defined(__cplusplus)
 390 #define NULL ((void*)0)
 391 #else
 392 #define NULL (0)
 393 #endif
 394 #endif
 395 #endif
 396
 397 #define FREE_BUF(_B) free(_B)
 398 #define ALLOC_BUF(_S) (char*)malloc(_S)
 399
 400 #ifndef OS_FSTAT
 401 #define OS_FSTAT fstat
 402 #endif
 403 struct stat;
 404 extern _IO_ssize_t _IO_read __P((int, void*, _IO_size_t));
 405 extern _IO_ssize_t _IO_write __P((int, const void*, _IO_size_t));
 406 extern _IO_off_t _IO_lseek __P((int, _IO_off_t, int));
 407 extern int _IO_close __P((int));
 408 extern int _IO_fstat __P((int, struct stat *));
 409
 410 /* Operations on _IO_fpos_t.
 411    Normally, these are trivial, but we provide hooks for configurations
 412    where an _IO_fpos_t is a struct.
 413    Note that _IO_off_t must be an integral type. */
 414
 415 /* _IO_pos_BAD is an _IO_fpos_t value indicating error, unknown, or EOF. */
 416 #ifndef _IO_pos_BAD
 417 #define _IO_pos_BAD ((_IO_fpos_t)(-1))
 418 #endif
 419 /* _IO_pos_as_off converts an _IO_fpos_t value to an _IO_off_t value. */
 420 #ifndef _IO_pos_as_off
 421 #define _IO_pos_as_off(__pos) ((_IO_off_t)(__pos))
 422 #endif
 423 /* _IO_pos_adjust adjust an _IO_fpos_t by some number of bytes. */
 424 #ifndef _IO_pos_adjust
 425 #define _IO_pos_adjust(__pos, __delta) ((__pos) += (__delta))
 426 #endif
 427 /* _IO_pos_0 is an _IO_fpos_t value indicating beginning of file. */
 428 #ifndef _IO_pos_0
 429 #define _IO_pos_0 ((_IO_fpos_t)0)
 430 #endif
 431
 432 #ifdef __cplusplus
 433 }
 434 #endif
 435
 436 /* check following! */
 437 #define FILEBUF_LITERAL(CHAIN, FLAGS, FD) \
 438        { _IO_MAGIC+_IO_LINKED+_IO_IS_FILEBUF+FLAGS, \
 439          0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, CHAIN, FD}
 440
 441 /* VTABLE_LABEL defines NAME as of the CLASS class.
 442    CNLENGTH is strlen(#CLASS).  */
 443 #ifdef __GNUC__
 444 #if _G_VTABLE_LABEL_HAS_LENGTH
 445 #define VTABLE_LABEL(NAME, CLASS, CNLENGTH) \
 446   extern char NAME[] asm (_G_VTABLE_LABEL_PREFIX #CNLENGTH #CLASS);
 447 #else
 448 #define VTABLE_LABEL(NAME, CLASS, CNLENGTH) \
 449   extern char NAME[] asm (_G_VTABLE_LABEL_PREFIX #CLASS);
 450 #endif
 451 #endif /* __GNUC__ */
 452
 453 #if !defined(builtinbuf_vtable) && defined(__cplusplus)
 454 #ifdef __GNUC__
 455 VTABLE_LABEL(builtinbuf_vtable, builtinbuf, 10)
 456 #else
 457 #if _G_VTABLE_LABEL_HAS_LENGTH
 458 #define builtinbuf_vtable _G_VTABLE_LABEL_PREFIX_ID##10builtinbuf
 459 #else
 460 #define builtinbuf_vtable _G_VTABLE_LABEL_PREFIX_ID##builtinbuf
 461 #endif
 462 #endif
 463 #endif /* !defined(builtinbuf_vtable) && defined(__cplusplus) */
 464
 465 #if defined(__STDC__) || defined(__cplusplus)
 466 #define _IO_va_start(args, last) va_start(args, last)
 467 #else
 468 #define _IO_va_start(args, last) va_start(args)
 469 #endif
 470
 471 extern struct _IO_fake_stdiobuf _IO_stdin_buf, _IO_stdout_buf, _IO_stderr_buf;
 472
 473 #if 1
 474 #define COERCE_FILE(FILE) /* Nothing */
 475 #else
 476 /* This is part of the kludge for binary compatibility with old stdio. */
 477 #define COERCE_FILE(FILE) \
 478   (((FILE)->_IO_file_flags & _IO_MAGIC_MASK) == _OLD_MAGIC_MASK \
 479     && (FILE) = *(FILE**)&((int*)fp)[1])
 480 #endif
 481
 482 #ifdef EINVAL
 483 #define MAYBE_SET_EINVAL errno = EINVAL
 484 #else
 485 #define MAYBE_SET_EINVAL /* nothing */
 486 #endif
 487
 488 #ifdef DEBUG
 489 #define CHECK_FILE(FILE,RET) \
 490         if ((FILE) == NULL) { MAYBE_SET_EINVAL; return RET; } \
 491         else { COERCE_FILE(FILE); \
 492                if (((FILE)->_IO_file_flags & _IO_MAGIC_MASK) != _IO_MAGIC) \
 493           { errno = EINVAL; return RET; }}
 494 #else
 495 #define CHECK_FILE(FILE,RET) \
 496         COERCE_FILE(FILE)
 497 #endif