1/* Copyright (C) 1993-2018 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 <http://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/* NOTE: libio is now exclusively used only by glibc since libstdc++ has its
28 own implementation. As a result, functions that were implemented for C++
29 (like *sputn) may no longer have C++ semantics. This is of course only
30 relevant for internal callers of these functions since these functions are
31 not intended for external use otherwise.
32
33 FIXME: All of the C++ cruft eventually needs to go away. */
34
35#include <stddef.h>
36
37#include <errno.h>
38#include <libc-lock.h>
39
40#include <math_ldbl_opt.h>
41
42#include "iolibio.h"
43
44#ifdef __cplusplus
45extern "C" {
46#endif
47
48#define _IO_seek_set 0
49#define _IO_seek_cur 1
50#define _IO_seek_end 2
51
52/* THE JUMPTABLE FUNCTIONS.
53
54 * The _IO_FILE type is used to implement the FILE type in GNU libc,
55 * as well as the streambuf class in GNU iostreams for C++.
56 * These are all the same, just used differently.
57 * An _IO_FILE (or FILE) object is allows followed by a pointer to
58 * a jump table (of pointers to functions). The pointer is accessed
59 * with the _IO_JUMPS macro. The jump table has an eccentric format,
60 * so as to be compatible with the layout of a C++ virtual function table.
61 * (as implemented by g++). When a pointer to a streambuf object is
62 * coerced to an (_IO_FILE*), then _IO_JUMPS on the result just
63 * happens to point to the virtual function table of the streambuf.
64 * Thus the _IO_JUMPS function table used for C stdio/libio does
65 * double duty as the virtual function table for C++ streambuf.
66 *
67 * The entries in the _IO_JUMPS function table (and hence also the
68 * virtual functions of a streambuf) are described below.
69 * The first parameter of each function entry is the _IO_FILE/streambuf
70 * object being acted on (i.e. the 'this' parameter).
71 */
72
73#include <shlib-compat.h>
74#if !SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
75 /* Setting this macro disables the use of the _vtable_offset bias in
76 _IO_JUMPS_FUNCS, below. That is only needed if we want to
77 support old binaries (see oldfileops.c). */
78# define _G_IO_NO_BACKWARD_COMPAT 1
79#endif
80
81#if (!defined _IO_USE_OLD_IO_FILE \
82 && (!defined _G_IO_NO_BACKWARD_COMPAT || _G_IO_NO_BACKWARD_COMPAT == 0))
83# define _IO_JUMPS_OFFSET 1
84#else
85# define _IO_JUMPS_OFFSET 0
86#endif
87
88/* Type of MEMBER in struct type TYPE. */
89#define _IO_MEMBER_TYPE(TYPE, MEMBER) __typeof__ (((TYPE){}).MEMBER)
90
91/* Essentially ((TYPE *) THIS)->MEMBER, but avoiding the aliasing
92 violation in case THIS has a different pointer type. */
93#define _IO_CAST_FIELD_ACCESS(THIS, TYPE, MEMBER) \
94 (*(_IO_MEMBER_TYPE (TYPE, MEMBER) *)(((char *) (THIS)) \
95 + offsetof(TYPE, MEMBER)))
96
97#define _IO_JUMPS(THIS) (THIS)->vtable
98#define _IO_JUMPS_FILE_plus(THIS) \
99 _IO_CAST_FIELD_ACCESS ((THIS), struct _IO_FILE_plus, vtable)
100#define _IO_WIDE_JUMPS(THIS) \
101 _IO_CAST_FIELD_ACCESS ((THIS), struct _IO_FILE, _wide_data)->_wide_vtable
102#define _IO_CHECK_WIDE(THIS) \
103 (_IO_CAST_FIELD_ACCESS ((THIS), struct _IO_FILE, _wide_data) != NULL)
104
105#if _IO_JUMPS_OFFSET
106# define _IO_JUMPS_FUNC(THIS) \
107 (IO_validate_vtable \
108 (*(struct _IO_jump_t **) ((void *) &_IO_JUMPS_FILE_plus (THIS) \
109 + (THIS)->_vtable_offset)))
110# define _IO_vtable_offset(THIS) (THIS)->_vtable_offset
111#else
112# define _IO_JUMPS_FUNC(THIS) (IO_validate_vtable (_IO_JUMPS_FILE_plus (THIS)))
113# define _IO_vtable_offset(THIS) 0
114#endif
115#define _IO_WIDE_JUMPS_FUNC(THIS) _IO_WIDE_JUMPS(THIS)
116#define JUMP_FIELD(TYPE, NAME) TYPE NAME
117#define JUMP0(FUNC, THIS) (_IO_JUMPS_FUNC(THIS)->FUNC) (THIS)
118#define JUMP1(FUNC, THIS, X1) (_IO_JUMPS_FUNC(THIS)->FUNC) (THIS, X1)
119#define JUMP2(FUNC, THIS, X1, X2) (_IO_JUMPS_FUNC(THIS)->FUNC) (THIS, X1, X2)
120#define JUMP3(FUNC, THIS, X1,X2,X3) (_IO_JUMPS_FUNC(THIS)->FUNC) (THIS, X1,X2, X3)
121#define JUMP_INIT(NAME, VALUE) VALUE
122#define JUMP_INIT_DUMMY JUMP_INIT(dummy, 0), JUMP_INIT (dummy2, 0)
123
124#define WJUMP0(FUNC, THIS) (_IO_WIDE_JUMPS_FUNC(THIS)->FUNC) (THIS)
125#define WJUMP1(FUNC, THIS, X1) (_IO_WIDE_JUMPS_FUNC(THIS)->FUNC) (THIS, X1)
126#define WJUMP2(FUNC, THIS, X1, X2) (_IO_WIDE_JUMPS_FUNC(THIS)->FUNC) (THIS, X1, X2)
127#define WJUMP3(FUNC, THIS, X1,X2,X3) (_IO_WIDE_JUMPS_FUNC(THIS)->FUNC) (THIS, X1,X2, X3)
128
129/* The 'finish' function does any final cleaning up of an _IO_FILE object.
130 It does not delete (free) it, but does everything else to finalize it.
131 It matches the streambuf::~streambuf virtual destructor. */
132typedef void (*_IO_finish_t) (_IO_FILE *, int); /* finalize */
133#define _IO_FINISH(FP) JUMP1 (__finish, FP, 0)
134#define _IO_WFINISH(FP) WJUMP1 (__finish, FP, 0)
135
136/* The 'overflow' hook flushes the buffer.
137 The second argument is a character, or EOF.
138 It matches the streambuf::overflow virtual function. */
139typedef int (*_IO_overflow_t) (_IO_FILE *, int);
140#define _IO_OVERFLOW(FP, CH) JUMP1 (__overflow, FP, CH)
141#define _IO_WOVERFLOW(FP, CH) WJUMP1 (__overflow, FP, CH)
142
143/* The 'underflow' hook tries to fills the get buffer.
144 It returns the next character (as an unsigned char) or EOF. The next
145 character remains in the get buffer, and the get position is not changed.
146 It matches the streambuf::underflow virtual function. */
147typedef int (*_IO_underflow_t) (_IO_FILE *);
148#define _IO_UNDERFLOW(FP) JUMP0 (__underflow, FP)
149#define _IO_WUNDERFLOW(FP) WJUMP0 (__underflow, FP)
150
151/* The 'uflow' hook returns the next character in the input stream
152 (cast to unsigned char), and increments the read position;
153 EOF is returned on failure.
154 It matches the streambuf::uflow virtual function, which is not in the
155 cfront implementation, but was added to C++ by the ANSI/ISO committee. */
156#define _IO_UFLOW(FP) JUMP0 (__uflow, FP)
157#define _IO_WUFLOW(FP) WJUMP0 (__uflow, FP)
158
159/* The 'pbackfail' hook handles backing up.
160 It matches the streambuf::pbackfail virtual function. */
161typedef int (*_IO_pbackfail_t) (_IO_FILE *, int);
162#define _IO_PBACKFAIL(FP, CH) JUMP1 (__pbackfail, FP, CH)
163#define _IO_WPBACKFAIL(FP, CH) WJUMP1 (__pbackfail, FP, CH)
164
165/* The 'xsputn' hook writes upto N characters from buffer DATA.
166 Returns EOF or the number of character actually written.
167 It matches the streambuf::xsputn virtual function. */
168typedef _IO_size_t (*_IO_xsputn_t) (_IO_FILE *FP, const void *DATA,
169 _IO_size_t N);
170#define _IO_XSPUTN(FP, DATA, N) JUMP2 (__xsputn, FP, DATA, N)
171#define _IO_WXSPUTN(FP, DATA, N) WJUMP2 (__xsputn, FP, DATA, N)
172
173/* The 'xsgetn' hook reads upto N characters into buffer DATA.
174 Returns the number of character actually read.
175 It matches the streambuf::xsgetn virtual function. */
176typedef _IO_size_t (*_IO_xsgetn_t) (_IO_FILE *FP, void *DATA, _IO_size_t N);
177#define _IO_XSGETN(FP, DATA, N) JUMP2 (__xsgetn, FP, DATA, N)
178#define _IO_WXSGETN(FP, DATA, N) WJUMP2 (__xsgetn, FP, DATA, N)
179
180/* The 'seekoff' hook moves the stream position to a new position
181 relative to the start of the file (if DIR==0), the current position
182 (MODE==1), or the end of the file (MODE==2).
183 It matches the streambuf::seekoff virtual function.
184 It is also used for the ANSI fseek function. */
185typedef _IO_off64_t (*_IO_seekoff_t) (_IO_FILE *FP, _IO_off64_t OFF, int DIR,
186 int MODE);
187#define _IO_SEEKOFF(FP, OFF, DIR, MODE) JUMP3 (__seekoff, FP, OFF, DIR, MODE)
188#define _IO_WSEEKOFF(FP, OFF, DIR, MODE) WJUMP3 (__seekoff, FP, OFF, DIR, MODE)
189
190/* The 'seekpos' hook also moves the stream position,
191 but to an absolute position given by a fpos64_t (seekpos).
192 It matches the streambuf::seekpos virtual function.
193 It is also used for the ANSI fgetpos and fsetpos functions. */
194/* The _IO_seek_cur and _IO_seek_end options are not allowed. */
195typedef _IO_off64_t (*_IO_seekpos_t) (_IO_FILE *, _IO_off64_t, int);
196#define _IO_SEEKPOS(FP, POS, FLAGS) JUMP2 (__seekpos, FP, POS, FLAGS)
197#define _IO_WSEEKPOS(FP, POS, FLAGS) WJUMP2 (__seekpos, FP, POS, FLAGS)
198
199/* The 'setbuf' hook gives a buffer to the file.
200 It matches the streambuf::setbuf virtual function. */
201typedef _IO_FILE* (*_IO_setbuf_t) (_IO_FILE *, char *, _IO_ssize_t);
202#define _IO_SETBUF(FP, BUFFER, LENGTH) JUMP2 (__setbuf, FP, BUFFER, LENGTH)
203#define _IO_WSETBUF(FP, BUFFER, LENGTH) WJUMP2 (__setbuf, FP, BUFFER, LENGTH)
204
205/* The 'sync' hook attempts to synchronize the internal data structures
206 of the file with the external state.
207 It matches the streambuf::sync virtual function. */
208typedef int (*_IO_sync_t) (_IO_FILE *);
209#define _IO_SYNC(FP) JUMP0 (__sync, FP)
210#define _IO_WSYNC(FP) WJUMP0 (__sync, FP)
211
212/* The 'doallocate' hook is used to tell the file to allocate a buffer.
213 It matches the streambuf::doallocate virtual function, which is not
214 in the ANSI/ISO C++ standard, but is part traditional implementations. */
215typedef int (*_IO_doallocate_t) (_IO_FILE *);
216#define _IO_DOALLOCATE(FP) JUMP0 (__doallocate, FP)
217#define _IO_WDOALLOCATE(FP) WJUMP0 (__doallocate, FP)
218
219/* The following four hooks (sysread, syswrite, sysclose, sysseek, and
220 sysstat) are low-level hooks specific to this implementation.
221 There is no correspondence in the ANSI/ISO C++ standard library.
222 The hooks basically correspond to the Unix system functions
223 (read, write, close, lseek, and stat) except that a _IO_FILE*
224 parameter is used instead of an integer file descriptor; the default
225 implementation used for normal files just calls those functions.
226 The advantage of overriding these functions instead of the higher-level
227 ones (underflow, overflow etc) is that you can leave all the buffering
228 higher-level functions. */
229
230/* The 'sysread' hook is used to read data from the external file into
231 an existing buffer. It generalizes the Unix read(2) function.
232 It matches the streambuf::sys_read virtual function, which is
233 specific to this implementation. */
234typedef _IO_ssize_t (*_IO_read_t) (_IO_FILE *, void *, _IO_ssize_t);
235#define _IO_SYSREAD(FP, DATA, LEN) JUMP2 (__read, FP, DATA, LEN)
236#define _IO_WSYSREAD(FP, DATA, LEN) WJUMP2 (__read, FP, DATA, LEN)
237
238/* The 'syswrite' hook is used to write data from an existing buffer
239 to an external file. It generalizes the Unix write(2) function.
240 It matches the streambuf::sys_write virtual function, which is
241 specific to this implementation. */
242typedef _IO_ssize_t (*_IO_write_t) (_IO_FILE *, const void *, _IO_ssize_t);
243#define _IO_SYSWRITE(FP, DATA, LEN) JUMP2 (__write, FP, DATA, LEN)
244#define _IO_WSYSWRITE(FP, DATA, LEN) WJUMP2 (__write, FP, DATA, LEN)
245
246/* The 'sysseek' hook is used to re-position an external file.
247 It generalizes the Unix lseek(2) function.
248 It matches the streambuf::sys_seek virtual function, which is
249 specific to this implementation. */
250typedef _IO_off64_t (*_IO_seek_t) (_IO_FILE *, _IO_off64_t, int);
251#define _IO_SYSSEEK(FP, OFFSET, MODE) JUMP2 (__seek, FP, OFFSET, MODE)
252#define _IO_WSYSSEEK(FP, OFFSET, MODE) WJUMP2 (__seek, FP, OFFSET, MODE)
253
254/* The 'sysclose' hook is used to finalize (close, finish up) an
255 external file. It generalizes the Unix close(2) function.
256 It matches the streambuf::sys_close virtual function, which is
257 specific to this implementation. */
258typedef int (*_IO_close_t) (_IO_FILE *); /* finalize */
259#define _IO_SYSCLOSE(FP) JUMP0 (__close, FP)
260#define _IO_WSYSCLOSE(FP) WJUMP0 (__close, FP)
261
262/* The 'sysstat' hook is used to get information about an external file
263 into a struct stat buffer. It generalizes the Unix fstat(2) call.
264 It matches the streambuf::sys_stat virtual function, which is
265 specific to this implementation. */
266typedef int (*_IO_stat_t) (_IO_FILE *, void *);
267#define _IO_SYSSTAT(FP, BUF) JUMP1 (__stat, FP, BUF)
268#define _IO_WSYSSTAT(FP, BUF) WJUMP1 (__stat, FP, BUF)
269
270/* The 'showmany' hook can be used to get an image how much input is
271 available. In many cases the answer will be 0 which means unknown
272 but some cases one can provide real information. */
273typedef int (*_IO_showmanyc_t) (_IO_FILE *);
274#define _IO_SHOWMANYC(FP) JUMP0 (__showmanyc, FP)
275#define _IO_WSHOWMANYC(FP) WJUMP0 (__showmanyc, FP)
276
277/* The 'imbue' hook is used to get information about the currently
278 installed locales. */
279typedef void (*_IO_imbue_t) (_IO_FILE *, void *);
280#define _IO_IMBUE(FP, LOCALE) JUMP1 (__imbue, FP, LOCALE)
281#define _IO_WIMBUE(FP, LOCALE) WJUMP1 (__imbue, FP, LOCALE)
282
283
284#define _IO_CHAR_TYPE char /* unsigned char ? */
285#define _IO_INT_TYPE int
286
287struct _IO_jump_t
288{
289 JUMP_FIELD(size_t, __dummy);
290 JUMP_FIELD(size_t, __dummy2);
291 JUMP_FIELD(_IO_finish_t, __finish);
292 JUMP_FIELD(_IO_overflow_t, __overflow);
293 JUMP_FIELD(_IO_underflow_t, __underflow);
294 JUMP_FIELD(_IO_underflow_t, __uflow);
295 JUMP_FIELD(_IO_pbackfail_t, __pbackfail);
296 /* showmany */
297 JUMP_FIELD(_IO_xsputn_t, __xsputn);
298 JUMP_FIELD(_IO_xsgetn_t, __xsgetn);
299 JUMP_FIELD(_IO_seekoff_t, __seekoff);
300 JUMP_FIELD(_IO_seekpos_t, __seekpos);
301 JUMP_FIELD(_IO_setbuf_t, __setbuf);
302 JUMP_FIELD(_IO_sync_t, __sync);
303 JUMP_FIELD(_IO_doallocate_t, __doallocate);
304 JUMP_FIELD(_IO_read_t, __read);
305 JUMP_FIELD(_IO_write_t, __write);
306 JUMP_FIELD(_IO_seek_t, __seek);
307 JUMP_FIELD(_IO_close_t, __close);
308 JUMP_FIELD(_IO_stat_t, __stat);
309 JUMP_FIELD(_IO_showmanyc_t, __showmanyc);
310 JUMP_FIELD(_IO_imbue_t, __imbue);
311#if 0
312 get_column;
313 set_column;
314#endif
315};
316
317/* We always allocate an extra word following an _IO_FILE.
318 This contains a pointer to the function jump table used.
319 This is for compatibility with C++ streambuf; the word can
320 be used to smash to a pointer to a virtual function table. */
321
322struct _IO_FILE_plus
323{
324 _IO_FILE file;
325 const struct _IO_jump_t *vtable;
326};
327
328#ifdef _IO_USE_OLD_IO_FILE
329/* This structure is used by the compatibility code as if it were an
330 _IO_FILE_plus, but has enough space to initialize the _mode argument
331 of an _IO_FILE_complete. */
332struct _IO_FILE_complete_plus
333{
334 struct _IO_FILE_complete file;
335 const struct _IO_jump_t *vtable;
336};
337#endif
338
339/* Special file type for fopencookie function. */
340struct _IO_cookie_file
341{
342 struct _IO_FILE_plus __fp;
343 void *__cookie;
344 _IO_cookie_io_functions_t __io_functions;
345};
346
347_IO_FILE *_IO_fopencookie (void *cookie, const char *mode,
348 _IO_cookie_io_functions_t io_functions);
349
350
351/* Iterator type for walking global linked list of _IO_FILE objects. */
352
353typedef struct _IO_FILE *_IO_ITER;
354
355/* Generic functions */
356
357extern void _IO_switch_to_main_get_area (_IO_FILE *) __THROW;
358extern void _IO_switch_to_backup_area (_IO_FILE *) __THROW;
359extern int _IO_switch_to_get_mode (_IO_FILE *);
360libc_hidden_proto (_IO_switch_to_get_mode)
361extern void _IO_init_internal (_IO_FILE *, int) attribute_hidden;
362extern int _IO_sputbackc (_IO_FILE *, int) __THROW;
363libc_hidden_proto (_IO_sputbackc)
364extern int _IO_sungetc (_IO_FILE *) __THROW;
365extern void _IO_un_link (struct _IO_FILE_plus *) __THROW;
366libc_hidden_proto (_IO_un_link)
367extern void _IO_link_in (struct _IO_FILE_plus *) __THROW;
368libc_hidden_proto (_IO_link_in)
369extern void _IO_doallocbuf (_IO_FILE *) __THROW;
370libc_hidden_proto (_IO_doallocbuf)
371extern void _IO_unsave_markers (_IO_FILE *) __THROW;
372libc_hidden_proto (_IO_unsave_markers)
373extern void _IO_setb (_IO_FILE *, char *, char *, int) __THROW;
374libc_hidden_proto (_IO_setb)
375extern unsigned _IO_adjust_column (unsigned, const char *, int) __THROW;
376libc_hidden_proto (_IO_adjust_column)
377#define _IO_sputn(__fp, __s, __n) _IO_XSPUTN (__fp, __s, __n)
378
379_IO_ssize_t _IO_least_wmarker (_IO_FILE *, wchar_t *) __THROW;
380libc_hidden_proto (_IO_least_wmarker)
381extern void _IO_switch_to_main_wget_area (_IO_FILE *) __THROW;
382libc_hidden_proto (_IO_switch_to_main_wget_area)
383extern void _IO_switch_to_wbackup_area (_IO_FILE *) __THROW;
384libc_hidden_proto (_IO_switch_to_wbackup_area)
385extern int _IO_switch_to_wget_mode (_IO_FILE *);
386libc_hidden_proto (_IO_switch_to_wget_mode)
387extern void _IO_wsetb (_IO_FILE *, wchar_t *, wchar_t *, int) __THROW;
388libc_hidden_proto (_IO_wsetb)
389extern wint_t _IO_sputbackwc (_IO_FILE *, wint_t) __THROW;
390libc_hidden_proto (_IO_sputbackwc)
391extern wint_t _IO_sungetwc (_IO_FILE *) __THROW;
392extern void _IO_wdoallocbuf (_IO_FILE *) __THROW;
393libc_hidden_proto (_IO_wdoallocbuf)
394extern void _IO_unsave_wmarkers (_IO_FILE *) __THROW;
395extern unsigned _IO_adjust_wcolumn (unsigned, const wchar_t *, int) __THROW;
396extern _IO_off64_t get_file_offset (_IO_FILE *fp);
397
398/* Marker-related function. */
399
400extern void _IO_init_marker (struct _IO_marker *, _IO_FILE *);
401extern void _IO_init_wmarker (struct _IO_marker *, _IO_FILE *);
402extern void _IO_remove_marker (struct _IO_marker *) __THROW;
403extern int _IO_marker_difference (struct _IO_marker *, struct _IO_marker *)
404 __THROW;
405extern int _IO_marker_delta (struct _IO_marker *) __THROW;
406extern int _IO_wmarker_delta (struct _IO_marker *) __THROW;
407extern int _IO_seekmark (_IO_FILE *, struct _IO_marker *, int) __THROW;
408extern int _IO_seekwmark (_IO_FILE *, struct _IO_marker *, int) __THROW;
409
410/* Functions for iterating global list and dealing with its lock */
411
412extern _IO_ITER _IO_iter_begin (void) __THROW;
413libc_hidden_proto (_IO_iter_begin)
414extern _IO_ITER _IO_iter_end (void) __THROW;
415libc_hidden_proto (_IO_iter_end)
416extern _IO_ITER _IO_iter_next (_IO_ITER) __THROW;
417libc_hidden_proto (_IO_iter_next)
418extern _IO_FILE *_IO_iter_file (_IO_ITER) __THROW;
419libc_hidden_proto (_IO_iter_file)
420extern void _IO_list_lock (void) __THROW;
421libc_hidden_proto (_IO_list_lock)
422extern void _IO_list_unlock (void) __THROW;
423libc_hidden_proto (_IO_list_unlock)
424extern void _IO_list_resetlock (void) __THROW;
425libc_hidden_proto (_IO_list_resetlock)
426extern void _IO_enable_locks (void) __THROW;
427libc_hidden_proto (_IO_enable_locks)
428
429/* Default jumptable functions. */
430
431extern int _IO_default_underflow (_IO_FILE *) __THROW;
432extern int _IO_default_uflow (_IO_FILE *);
433libc_hidden_proto (_IO_default_uflow)
434extern wint_t _IO_wdefault_uflow (_IO_FILE *);
435libc_hidden_proto (_IO_wdefault_uflow)
436extern int _IO_default_doallocate (_IO_FILE *) __THROW;
437libc_hidden_proto (_IO_default_doallocate)
438extern int _IO_wdefault_doallocate (_IO_FILE *) __THROW;
439libc_hidden_proto (_IO_wdefault_doallocate)
440extern void _IO_default_finish (_IO_FILE *, int) __THROW;
441libc_hidden_proto (_IO_default_finish)
442extern void _IO_wdefault_finish (_IO_FILE *, int) __THROW;
443libc_hidden_proto (_IO_wdefault_finish)
444extern int _IO_default_pbackfail (_IO_FILE *, int) __THROW;
445libc_hidden_proto (_IO_default_pbackfail)
446extern wint_t _IO_wdefault_pbackfail (_IO_FILE *, wint_t) __THROW;
447libc_hidden_proto (_IO_wdefault_pbackfail)
448extern _IO_FILE* _IO_default_setbuf (_IO_FILE *, char *, _IO_ssize_t);
449extern _IO_size_t _IO_default_xsputn (_IO_FILE *, const void *, _IO_size_t);
450libc_hidden_proto (_IO_default_xsputn)
451extern _IO_size_t _IO_wdefault_xsputn (_IO_FILE *, const void *, _IO_size_t);
452libc_hidden_proto (_IO_wdefault_xsputn)
453extern _IO_size_t _IO_default_xsgetn (_IO_FILE *, void *, _IO_size_t);
454libc_hidden_proto (_IO_default_xsgetn)
455extern _IO_size_t _IO_wdefault_xsgetn (_IO_FILE *, void *, _IO_size_t);
456libc_hidden_proto (_IO_wdefault_xsgetn)
457extern _IO_off64_t _IO_default_seekoff (_IO_FILE *, _IO_off64_t, int, int)
458 __THROW;
459extern _IO_off64_t _IO_default_seekpos (_IO_FILE *, _IO_off64_t, int);
460extern _IO_ssize_t _IO_default_write (_IO_FILE *, const void *, _IO_ssize_t);
461extern _IO_ssize_t _IO_default_read (_IO_FILE *, void *, _IO_ssize_t);
462extern int _IO_default_stat (_IO_FILE *, void *) __THROW;
463extern _IO_off64_t _IO_default_seek (_IO_FILE *, _IO_off64_t, int) __THROW;
464extern int _IO_default_sync (_IO_FILE *) __THROW;
465#define _IO_default_close ((_IO_close_t) _IO_default_sync)
466extern int _IO_default_showmanyc (_IO_FILE *) __THROW;
467extern void _IO_default_imbue (_IO_FILE *, void *) __THROW;
468
469extern const struct _IO_jump_t _IO_file_jumps;
470libc_hidden_proto (_IO_file_jumps)
471extern const struct _IO_jump_t _IO_file_jumps_mmap attribute_hidden;
472extern const struct _IO_jump_t _IO_file_jumps_maybe_mmap attribute_hidden;
473extern const struct _IO_jump_t _IO_wfile_jumps;
474libc_hidden_proto (_IO_wfile_jumps)
475extern const struct _IO_jump_t _IO_wfile_jumps_mmap attribute_hidden;
476extern const struct _IO_jump_t _IO_wfile_jumps_maybe_mmap attribute_hidden;
477extern const struct _IO_jump_t _IO_old_file_jumps attribute_hidden;
478extern const struct _IO_jump_t _IO_streambuf_jumps;
479extern const struct _IO_jump_t _IO_old_proc_jumps attribute_hidden;
480extern const struct _IO_jump_t _IO_str_jumps attribute_hidden;
481extern const struct _IO_jump_t _IO_wstr_jumps attribute_hidden;
482extern const struct _IO_codecvt __libio_codecvt attribute_hidden;
483extern int _IO_do_write (_IO_FILE *, const char *, _IO_size_t);
484libc_hidden_proto (_IO_do_write)
485extern int _IO_new_do_write (_IO_FILE *, const char *, _IO_size_t);
486extern int _IO_old_do_write (_IO_FILE *, const char *, _IO_size_t);
487extern int _IO_wdo_write (_IO_FILE *, const wchar_t *, _IO_size_t);
488libc_hidden_proto (_IO_wdo_write)
489extern int _IO_flush_all_lockp (int);
490extern int _IO_flush_all (void);
491libc_hidden_proto (_IO_flush_all)
492extern int _IO_cleanup (void);
493extern void _IO_flush_all_linebuffered (void);
494libc_hidden_proto (_IO_flush_all_linebuffered)
495extern int _IO_new_fgetpos (_IO_FILE *, _IO_fpos_t *);
496extern int _IO_old_fgetpos (_IO_FILE *, _IO_fpos_t *);
497extern int _IO_new_fsetpos (_IO_FILE *, const _IO_fpos_t *);
498extern int _IO_old_fsetpos (_IO_FILE *, const _IO_fpos_t *);
499extern int _IO_new_fgetpos64 (_IO_FILE *, _IO_fpos64_t *);
500extern int _IO_old_fgetpos64 (_IO_FILE *, _IO_fpos64_t *);
501extern int _IO_new_fsetpos64 (_IO_FILE *, const _IO_fpos64_t *);
502extern int _IO_old_fsetpos64 (_IO_FILE *, const _IO_fpos64_t *);
503extern void _IO_old_init (_IO_FILE *fp, int flags) __THROW;
504
505
506#define _IO_do_flush(_f) \
507 ((_f)->_mode <= 0 \
508 ? _IO_do_write(_f, (_f)->_IO_write_base, \
509 (_f)->_IO_write_ptr-(_f)->_IO_write_base) \
510 : _IO_wdo_write(_f, (_f)->_wide_data->_IO_write_base, \
511 ((_f)->_wide_data->_IO_write_ptr \
512 - (_f)->_wide_data->_IO_write_base)))
513#define _IO_old_do_flush(_f) \
514 _IO_old_do_write(_f, (_f)->_IO_write_base, \
515 (_f)->_IO_write_ptr-(_f)->_IO_write_base)
516#define _IO_in_put_mode(_fp) ((_fp)->_flags & _IO_CURRENTLY_PUTTING)
517#define _IO_mask_flags(fp, f, mask) \
518 ((fp)->_flags = ((fp)->_flags & ~(mask)) | ((f) & (mask)))
519#define _IO_setg(fp, eb, g, eg) ((fp)->_IO_read_base = (eb),\
520 (fp)->_IO_read_ptr = (g), (fp)->_IO_read_end = (eg))
521#define _IO_wsetg(fp, eb, g, eg) ((fp)->_wide_data->_IO_read_base = (eb),\
522 (fp)->_wide_data->_IO_read_ptr = (g), \
523 (fp)->_wide_data->_IO_read_end = (eg))
524#define _IO_setp(__fp, __p, __ep) \
525 ((__fp)->_IO_write_base = (__fp)->_IO_write_ptr \
526 = __p, (__fp)->_IO_write_end = (__ep))
527#define _IO_wsetp(__fp, __p, __ep) \
528 ((__fp)->_wide_data->_IO_write_base \
529 = (__fp)->_wide_data->_IO_write_ptr = __p, \
530 (__fp)->_wide_data->_IO_write_end = (__ep))
531#define _IO_have_backup(fp) ((fp)->_IO_save_base != NULL)
532#define _IO_have_wbackup(fp) ((fp)->_wide_data->_IO_save_base != NULL)
533#define _IO_in_backup(fp) ((fp)->_flags & _IO_IN_BACKUP)
534#define _IO_have_markers(fp) ((fp)->_markers != NULL)
535#define _IO_blen(fp) ((fp)->_IO_buf_end - (fp)->_IO_buf_base)
536#define _IO_wblen(fp) ((fp)->_wide_data->_IO_buf_end \
537 - (fp)->_wide_data->_IO_buf_base)
538
539/* Jumptable functions for files. */
540
541extern int _IO_file_doallocate (_IO_FILE *) __THROW;
542libc_hidden_proto (_IO_file_doallocate)
543extern _IO_FILE* _IO_file_setbuf (_IO_FILE *, char *, _IO_ssize_t);
544libc_hidden_proto (_IO_file_setbuf)
545extern _IO_off64_t _IO_file_seekoff (_IO_FILE *, _IO_off64_t, int, int);
546libc_hidden_proto (_IO_file_seekoff)
547extern _IO_off64_t _IO_file_seekoff_mmap (_IO_FILE *, _IO_off64_t, int, int)
548 __THROW;
549extern _IO_size_t _IO_file_xsputn (_IO_FILE *, const void *, _IO_size_t);
550libc_hidden_proto (_IO_file_xsputn)
551extern _IO_size_t _IO_file_xsgetn (_IO_FILE *, void *, _IO_size_t);
552libc_hidden_proto (_IO_file_xsgetn)
553extern int _IO_file_stat (_IO_FILE *, void *) __THROW;
554libc_hidden_proto (_IO_file_stat)
555extern int _IO_file_close (_IO_FILE *) __THROW;
556libc_hidden_proto (_IO_file_close)
557extern int _IO_file_close_mmap (_IO_FILE *) __THROW;
558extern int _IO_file_underflow (_IO_FILE *);
559libc_hidden_proto (_IO_file_underflow)
560extern int _IO_file_underflow_mmap (_IO_FILE *);
561extern int _IO_file_underflow_maybe_mmap (_IO_FILE *);
562extern int _IO_file_overflow (_IO_FILE *, int);
563libc_hidden_proto (_IO_file_overflow)
564#define _IO_file_is_open(__fp) ((__fp)->_fileno != -1)
565extern _IO_FILE* _IO_file_attach (_IO_FILE *, int);
566libc_hidden_proto (_IO_file_attach)
567extern _IO_FILE* _IO_file_open (_IO_FILE *, const char *, int, int, int, int);
568libc_hidden_proto (_IO_file_open)
569extern _IO_FILE* _IO_file_fopen (_IO_FILE *, const char *, const char *, int);
570libc_hidden_proto (_IO_file_fopen)
571extern _IO_ssize_t _IO_file_write (_IO_FILE *, const void *, _IO_ssize_t);
572extern _IO_ssize_t _IO_file_read (_IO_FILE *, void *, _IO_ssize_t);
573libc_hidden_proto (_IO_file_read)
574extern int _IO_file_sync (_IO_FILE *);
575libc_hidden_proto (_IO_file_sync)
576extern int _IO_file_close_it (_IO_FILE *);
577libc_hidden_proto (_IO_file_close_it)
578extern _IO_off64_t _IO_file_seek (_IO_FILE *, _IO_off64_t, int) __THROW;
579libc_hidden_proto (_IO_file_seek)
580extern void _IO_file_finish (_IO_FILE *, int);
581libc_hidden_proto (_IO_file_finish)
582
583extern _IO_FILE* _IO_new_file_attach (_IO_FILE *, int);
584extern int _IO_new_file_close_it (_IO_FILE *);
585extern void _IO_new_file_finish (_IO_FILE *, int);
586extern _IO_FILE* _IO_new_file_fopen (_IO_FILE *, const char *, const char *,
587 int);
588extern void _IO_no_init (_IO_FILE *, int, int, struct _IO_wide_data *,
589 const struct _IO_jump_t *) __THROW;
590extern void _IO_new_file_init_internal (struct _IO_FILE_plus *)
591 __THROW attribute_hidden;
592extern _IO_FILE* _IO_new_file_setbuf (_IO_FILE *, char *, _IO_ssize_t);
593extern _IO_FILE* _IO_file_setbuf_mmap (_IO_FILE *, char *, _IO_ssize_t);
594extern int _IO_new_file_sync (_IO_FILE *);
595extern int _IO_new_file_underflow (_IO_FILE *);
596extern int _IO_new_file_overflow (_IO_FILE *, int);
597extern _IO_off64_t _IO_new_file_seekoff (_IO_FILE *, _IO_off64_t, int, int);
598extern _IO_ssize_t _IO_new_file_write (_IO_FILE *, const void *, _IO_ssize_t);
599extern _IO_size_t _IO_new_file_xsputn (_IO_FILE *, const void *, _IO_size_t);
600
601extern _IO_FILE* _IO_old_file_setbuf (_IO_FILE *, char *, _IO_ssize_t);
602extern _IO_off64_t _IO_old_file_seekoff (_IO_FILE *, _IO_off64_t, int, int);
603extern _IO_size_t _IO_old_file_xsputn (_IO_FILE *, const void *, _IO_size_t);
604extern int _IO_old_file_underflow (_IO_FILE *);
605extern int _IO_old_file_overflow (_IO_FILE *, int);
606extern void _IO_old_file_init_internal (struct _IO_FILE_plus *)
607 __THROW attribute_hidden;
608extern _IO_FILE* _IO_old_file_attach (_IO_FILE *, int);
609extern _IO_FILE* _IO_old_file_fopen (_IO_FILE *, const char *, const char *);
610extern _IO_ssize_t _IO_old_file_write (_IO_FILE *, const void *, _IO_ssize_t);
611extern int _IO_old_file_sync (_IO_FILE *);
612extern int _IO_old_file_close_it (_IO_FILE *);
613extern void _IO_old_file_finish (_IO_FILE *, int);
614
615extern int _IO_wfile_doallocate (_IO_FILE *) __THROW;
616extern _IO_size_t _IO_wfile_xsputn (_IO_FILE *, const void *, _IO_size_t);
617libc_hidden_proto (_IO_wfile_xsputn)
618extern _IO_FILE* _IO_wfile_setbuf (_IO_FILE *, wchar_t *, _IO_ssize_t);
619extern wint_t _IO_wfile_sync (_IO_FILE *);
620libc_hidden_proto (_IO_wfile_sync)
621extern wint_t _IO_wfile_underflow (_IO_FILE *);
622libc_hidden_proto (_IO_wfile_underflow)
623extern wint_t _IO_wfile_overflow (_IO_FILE *, wint_t);
624libc_hidden_proto (_IO_wfile_overflow)
625extern _IO_off64_t _IO_wfile_seekoff (_IO_FILE *, _IO_off64_t, int, int);
626libc_hidden_proto (_IO_wfile_seekoff)
627
628/* Jumptable functions for proc_files. */
629extern _IO_FILE* _IO_proc_open (_IO_FILE *, const char *, const char *)
630 __THROW;
631extern _IO_FILE* _IO_new_proc_open (_IO_FILE *, const char *, const char *)
632 __THROW;
633extern _IO_FILE* _IO_old_proc_open (_IO_FILE *, const char *, const char *);
634extern int _IO_proc_close (_IO_FILE *) __THROW;
635extern int _IO_new_proc_close (_IO_FILE *) __THROW;
636extern int _IO_old_proc_close (_IO_FILE *);
637
638/* Jumptable functions for strfiles. */
639extern int _IO_str_underflow (_IO_FILE *) __THROW;
640libc_hidden_proto (_IO_str_underflow)
641extern int _IO_str_overflow (_IO_FILE *, int) __THROW;
642libc_hidden_proto (_IO_str_overflow)
643extern int _IO_str_pbackfail (_IO_FILE *, int) __THROW;
644libc_hidden_proto (_IO_str_pbackfail)
645extern _IO_off64_t _IO_str_seekoff (_IO_FILE *, _IO_off64_t, int, int) __THROW;
646libc_hidden_proto (_IO_str_seekoff)
647extern void _IO_str_finish (_IO_FILE *, int) __THROW;
648
649/* Other strfile functions */
650struct _IO_strfile_;
651extern _IO_ssize_t _IO_str_count (_IO_FILE *) __THROW;
652
653/* And the wide character versions. */
654extern void _IO_wstr_init_static (_IO_FILE *, wchar_t *, _IO_size_t, wchar_t *)
655 __THROW;
656extern _IO_ssize_t _IO_wstr_count (_IO_FILE *) __THROW;
657extern _IO_wint_t _IO_wstr_overflow (_IO_FILE *, _IO_wint_t) __THROW;
658extern _IO_wint_t _IO_wstr_underflow (_IO_FILE *) __THROW;
659extern _IO_off64_t _IO_wstr_seekoff (_IO_FILE *, _IO_off64_t, int, int)
660 __THROW;
661extern _IO_wint_t _IO_wstr_pbackfail (_IO_FILE *, _IO_wint_t) __THROW;
662extern void _IO_wstr_finish (_IO_FILE *, int) __THROW;
663
664extern int _IO_vasprintf (char **result_ptr, const char *format,
665 _IO_va_list args) __THROW;
666extern int _IO_vdprintf (int d, const char *format, _IO_va_list arg);
667extern int _IO_vsnprintf (char *string, _IO_size_t maxlen,
668 const char *format, _IO_va_list args) __THROW;
669
670
671extern _IO_size_t _IO_getline (_IO_FILE *,char *, _IO_size_t, int, int);
672libc_hidden_proto (_IO_getline)
673extern _IO_size_t _IO_getline_info (_IO_FILE *,char *, _IO_size_t,
674 int, int, int *);
675libc_hidden_proto (_IO_getline_info)
676extern _IO_ssize_t _IO_getdelim (char **, _IO_size_t *, int, _IO_FILE *);
677extern _IO_size_t _IO_getwline (_IO_FILE *,wchar_t *, _IO_size_t, wint_t, int);
678extern _IO_size_t _IO_getwline_info (_IO_FILE *,wchar_t *, _IO_size_t,
679 wint_t, int, wint_t *);
680
681extern struct _IO_FILE_plus *_IO_list_all;
682libc_hidden_proto (_IO_list_all)
683extern void (*_IO_cleanup_registration_needed) (void);
684
685extern void _IO_str_init_static_internal (struct _IO_strfile_ *, char *,
686 _IO_size_t, char *) __THROW;
687extern _IO_off64_t _IO_seekoff_unlocked (_IO_FILE *, _IO_off64_t, int, int)
688 attribute_hidden;
689extern _IO_off64_t _IO_seekpos_unlocked (_IO_FILE *, _IO_off64_t, int)
690 attribute_hidden;
691
692#ifndef EOF
693# define EOF (-1)
694#endif
695
696#if _G_HAVE_MMAP
697
698# include <unistd.h>
699# include <fcntl.h>
700# include <sys/mman.h>
701# include <sys/param.h>
702
703# if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
704# define MAP_ANONYMOUS MAP_ANON
705# endif
706
707# if !defined(MAP_ANONYMOUS) || !defined(EXEC_PAGESIZE)
708# undef _G_HAVE_MMAP
709# define _G_HAVE_MMAP 0
710# endif
711
712#endif /* _G_HAVE_MMAP */
713
714extern int _IO_vscanf (const char *, _IO_va_list) __THROW;
715
716/* _IO_pos_BAD is an _IO_off64_t value indicating error, unknown, or EOF. */
717#ifndef _IO_pos_BAD
718# define _IO_pos_BAD ((_IO_off64_t) -1)
719#endif
720/* _IO_pos_adjust adjust an _IO_off64_t by some number of bytes. */
721#ifndef _IO_pos_adjust
722# define _IO_pos_adjust(pos, delta) ((pos) += (delta))
723#endif
724/* _IO_pos_0 is an _IO_off64_t value indicating beginning of file. */
725#ifndef _IO_pos_0
726# define _IO_pos_0 ((_IO_off64_t) 0)
727#endif
728
729#ifdef __cplusplus
730}
731#endif
732
733#ifdef _IO_MTSAFE_IO
734/* check following! */
735# ifdef _IO_USE_OLD_IO_FILE
736# define FILEBUF_LITERAL(CHAIN, FLAGS, FD, WDP) \
737 { _IO_MAGIC+_IO_LINKED+_IO_IS_FILEBUF+FLAGS, \
738 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, (_IO_FILE *) CHAIN, FD, \
739 0, _IO_pos_BAD, 0, 0, { 0 }, &_IO_stdfile_##FD##_lock }
740# else
741# define FILEBUF_LITERAL(CHAIN, FLAGS, FD, WDP) \
742 { _IO_MAGIC+_IO_LINKED+_IO_IS_FILEBUF+FLAGS, \
743 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, (_IO_FILE *) CHAIN, FD, \
744 0, _IO_pos_BAD, 0, 0, { 0 }, &_IO_stdfile_##FD##_lock, _IO_pos_BAD,\
745 NULL, WDP, 0 }
746# endif
747#else
748# ifdef _IO_USE_OLD_IO_FILE
749# define FILEBUF_LITERAL(CHAIN, FLAGS, FD, WDP) \
750 { _IO_MAGIC+_IO_LINKED+_IO_IS_FILEBUF+FLAGS, \
751 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, (_IO_FILE *) CHAIN, FD, \
752 0, _IO_pos_BAD }
753# else
754# define FILEBUF_LITERAL(CHAIN, FLAGS, FD, WDP) \
755 { _IO_MAGIC+_IO_LINKED+_IO_IS_FILEBUF+FLAGS, \
756 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, (_IO_FILE *) CHAIN, FD, \
757 0, _IO_pos_BAD, 0, 0, { 0 }, 0, _IO_pos_BAD, \
758 NULL, WDP, 0 }
759# endif
760#endif
761
762#define _IO_va_start(args, last) va_start(args, last)
763
764extern struct _IO_fake_stdiobuf _IO_stdin_buf, _IO_stdout_buf, _IO_stderr_buf;
765
766#if 1
767# define COERCE_FILE(FILE) /* Nothing */
768#else
769/* This is part of the kludge for binary compatibility with old stdio. */
770# define COERCE_FILE(FILE) \
771 (((FILE)->_IO_file_flags & _IO_MAGIC_MASK) == _OLD_MAGIC_MASK \
772 && (FILE) = *(FILE**)&((int*)fp)[1])
773#endif
774
775#ifdef EINVAL
776# define MAYBE_SET_EINVAL __set_errno (EINVAL)
777#else
778# define MAYBE_SET_EINVAL /* nothing */
779#endif
780
781#ifdef IO_DEBUG
782# define CHECK_FILE(FILE, RET) \
783 if ((FILE) == NULL) { MAYBE_SET_EINVAL; return RET; } \
784 else { COERCE_FILE(FILE); \
785 if (((FILE)->_IO_file_flags & _IO_MAGIC_MASK) != _IO_MAGIC) \
786 { MAYBE_SET_EINVAL; return RET; }}
787#else
788# define CHECK_FILE(FILE, RET) COERCE_FILE (FILE)
789#endif
790
791static inline void
792__attribute__ ((__always_inline__))
793_IO_acquire_lock_fct (_IO_FILE **p)
794{
795 _IO_FILE *fp = *p;
796 if ((fp->_flags & _IO_USER_LOCK) == 0)
797 _IO_funlockfile (fp);
798}
799
800static inline void
801__attribute__ ((__always_inline__))
802_IO_acquire_lock_clear_flags2_fct (_IO_FILE **p)
803{
804 _IO_FILE *fp = *p;
805 fp->_flags2 &= ~(_IO_FLAGS2_FORTIFY | _IO_FLAGS2_SCANF_STD);
806 if ((fp->_flags & _IO_USER_LOCK) == 0)
807 _IO_funlockfile (fp);
808}
809
810#if !defined _IO_MTSAFE_IO && IS_IN (libc)
811# define _IO_acquire_lock(_fp) \
812 do { \
813 _IO_FILE *_IO_acquire_lock_file = NULL
814# define _IO_acquire_lock_clear_flags2(_fp) \
815 do { \
816 _IO_FILE *_IO_acquire_lock_file = (_fp)
817# define _IO_release_lock(_fp) \
818 if (_IO_acquire_lock_file != NULL) \
819 _IO_acquire_lock_file->_flags2 &= ~(_IO_FLAGS2_FORTIFY \
820 | _IO_FLAGS2_SCANF_STD); \
821 } while (0)
822#endif
823
824/* Collect all vtables in a special section for vtable verification.
825 These symbols cover the extent of this section. */
826symbol_set_declare (__libc_IO_vtables)
827
828/* libio vtables need to carry this attribute so that they pass
829 validation. */
830#define libio_vtable __attribute__ ((section ("__libc_IO_vtables")))
831
832#ifdef SHARED
833/* If equal to &_IO_vtable_check (with pointer guard protection),
834 unknown vtable pointers are valid. This function pointer is solely
835 used as a flag. */
836extern void (*IO_accept_foreign_vtables) (void) attribute_hidden;
837
838/* Assigns the passed function pointer (either NULL or
839 &_IO_vtable_check) to IO_accept_foreign_vtables. */
840static inline void
841IO_set_accept_foreign_vtables (void (*flag) (void))
842{
843#ifdef PTR_MANGLE
844 PTR_MANGLE (flag);
845#endif
846 atomic_store_relaxed (&IO_accept_foreign_vtables, flag);
847}
848
849#else /* !SHARED */
850
851/* The statically-linked version does nothing. */
852static inline void
853IO_set_accept_foreign_vtables (void (*flag) (void))
854{
855}
856
857#endif
858
859/* Check if unknown vtable pointers are permitted; otherwise,
860 terminate the process. */
861void _IO_vtable_check (void) attribute_hidden;
862
863/* Perform vtable pointer validation. If validation fails, terminate
864 the process. */
865static inline const struct _IO_jump_t *
866IO_validate_vtable (const struct _IO_jump_t *vtable)
867{
868 /* Fast path: The vtable pointer is within the __libc_IO_vtables
869 section. */
870 uintptr_t section_length = __stop___libc_IO_vtables - __start___libc_IO_vtables;
871 const char *ptr = (const char *) vtable;
872 uintptr_t offset = ptr - __start___libc_IO_vtables;
873 if (__glibc_unlikely (offset >= section_length))
874 /* The vtable pointer is not in the expected section. Use the
875 slow path, which will terminate the process if necessary. */
876 _IO_vtable_check ();
877 return vtable;
878}
879