1/*	$OpenBSD: local.h,v 1.12 2005/10/10 17:37:44 espie Exp $	*/
2
3/*-
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#ifndef __BIONIC_STDIO_LOCAL_H__
36#define __BIONIC_STDIO_LOCAL_H__
37
38#include <pthread.h>
39#include <stdbool.h>
40#include <wchar.h>
41#include "wcio.h"
42
43/*
44 * Information local to this implementation of stdio,
45 * in particular, macros and private variables.
46 */
47
48__BEGIN_DECLS
49
50struct __sbuf {
51  unsigned char* _base;
52#if defined(__LP64__)
53  size_t _size;
54#else
55  int _size;
56#endif
57};
58
59struct __sFILE {
60	unsigned char *_p;	/* current position in (some) buffer */
61	int	_r;		/* read space left for getc() */
62	int	_w;		/* write space left for putc() */
63#if defined(__LP64__)
64	int	_flags;		/* flags, below; this FILE is free if 0 */
65	int	_file;		/* fileno, if Unix descriptor, else -1 */
66#else
67	short	_flags;		/* flags, below; this FILE is free if 0 */
68	short	_file;		/* fileno, if Unix descriptor, else -1 */
69#endif
70	struct	__sbuf _bf;	/* the buffer (at least 1 byte, if !NULL) */
71	int	_lbfsize;	/* 0 or -_bf._size, for inline putc */
72
73	// Function pointers used by `funopen`.
74	// Note that `_seek` is ignored if `_seek64` (in __sfileext) is set.
75	// TODO: NetBSD has `funopen2` which corrects the `int`s to `size_t`s.
76	// TODO: glibc has `fopencookie` which passes the function pointers in a struct.
77	void* _cookie;	/* cookie passed to io functions */
78	int (*_close)(void*);
79	int (*_read)(void*, char*, int);
80	fpos_t (*_seek)(void*, fpos_t, int);
81	int (*_write)(void*, const char*, int);
82
83	/* extension data, to avoid further ABI breakage */
84	struct	__sbuf _ext;
85	/* data for long sequences of ungetc() */
86	unsigned char *_up;	/* saved _p when _p is doing ungetc data */
87	int	_ur;		/* saved _r when _r is counting ungetc data */
88
89	/* tricks to meet minimum requirements even when malloc() fails */
90	unsigned char _ubuf[3];	/* guarantee an ungetc() buffer */
91	unsigned char _nbuf[1];	/* guarantee a getc() buffer */
92
93	/* separate buffer for fgetln() when line crosses buffer boundary */
94	struct	__sbuf _lb;	/* buffer for fgetln() */
95
96	/* Unix stdio files get aligned to block boundaries on fseek() */
97	int	_blksize;	/* stat.st_blksize (may be != _bf._size) */
98
99	fpos_t _unused_0; // This was the `_offset` field (see below).
100
101	// Do not add new fields here. (Or remove or change the size of any above.)
102	// Although bionic currently exports `stdin`, `stdout`, and `stderr` symbols,
103	// that still hasn't made it to the NDK. All NDK-built apps index directly
104	// into an array of this struct (which was in <stdio.h> historically), so if
105	// you need to make any changes, they need to be in the `__sfileext` struct
106	// below, and accessed via `_EXT`.
107};
108
109struct __sfileext {
110  // ungetc buffer.
111  struct __sbuf _ub;
112
113  // Wide char io status.
114  struct wchar_io_data _wcio;
115
116  // File lock.
117  pthread_mutex_t _lock;
118
119  // __fsetlocking support.
120  bool _caller_handles_locking;
121
122  // Equivalent to `_seek` but for _FILE_OFFSET_BITS=64.
123  // Callers should use this but fall back to `__sFILE::_seek`.
124  off64_t (*_seek64)(void*, off64_t, int);
125};
126
127// Values for `__sFILE::_flags`.
128#define __SLBF 0x0001  // Line buffered.
129#define __SNBF 0x0002  // Unbuffered.
130// RD and WR are never simultaneously asserted: use _SRW instead.
131#define __SRD  0x0004  // OK to read.
132#define __SWR  0x0008  // OK to write.
133#define __SRW  0x0010  // Open for reading & writing.
134#define __SEOF 0x0020  // Found EOF.
135#define __SERR 0x0040  // Found error.
136#define __SMBF 0x0080  // `_buf` is from malloc.
137#define __SAPP 0x0100  // fdopen()ed in append mode.
138#define __SSTR 0x0200  // This is an sprintf/snprintf string.
139// #define __SOPT 0x0400 --- historical (do fseek() optimization).
140// #define __SNPT 0x0800 --- historical (do not do fseek() optimization).
141// #define __SOFF 0x1000 --- historical (set iff _offset is in fact correct).
142#define __SMOD 0x2000  // true => fgetln modified _p text.
143#define __SALC 0x4000  // Allocate string space dynamically.
144#define __SIGN 0x8000  // Ignore this file in _fwalk.
145
146// TODO: remove remaining references to these obsolete flags.
147#define __SNPT 0
148#define __SOPT 0
149
150#if defined(__cplusplus)
151#define _EXT(fp) reinterpret_cast<__sfileext*>((fp)->_ext._base)
152#else
153#define _EXT(fp) ((struct __sfileext *)((fp)->_ext._base))
154#endif
155
156#define _UB(fp) _EXT(fp)->_ub
157#define _FLOCK(fp)  _EXT(fp)->_lock
158
159#define _FILEEXT_INIT(fp) \
160do { \
161	_UB(fp)._base = NULL; \
162	_UB(fp)._size = 0; \
163	WCIO_INIT(fp); \
164	pthread_mutexattr_t attr; \
165	pthread_mutexattr_init(&attr); \
166	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); \
167	pthread_mutex_init(&_FLOCK(fp), &attr); \
168	pthread_mutexattr_destroy(&attr); \
169	_EXT(fp)->_caller_handles_locking = false; \
170} while (0)
171
172#define _FILEEXT_SETUP(f, fext) \
173do { \
174	(f)->_ext._base = (unsigned char *)(fext); \
175	_FILEEXT_INIT(f); \
176} while (0)
177
178/*
179 * Android <= KitKat had getc/putc macros in <stdio.h> that referred
180 * to __srget/__swbuf, so those symbols need to be public for LP32
181 * but can be hidden for LP64.
182 */
183__LIBC32_LEGACY_PUBLIC__ int __srget(FILE*);
184__LIBC32_LEGACY_PUBLIC__ int __swbuf(int, FILE*);
185__LIBC32_LEGACY_PUBLIC__ int __srefill(FILE*);
186
187/* This was referenced by the apportable middleware for LP32. */
188__LIBC32_LEGACY_PUBLIC__ int __swsetup(FILE*);
189
190/* These were referenced by a couple of different pieces of middleware and the Crystax NDK. */
191__LIBC32_LEGACY_PUBLIC__ int __sflags(const char*, int*);
192__LIBC32_LEGACY_PUBLIC__ FILE* __sfp(void);
193__LIBC32_LEGACY_PUBLIC__ void __smakebuf(FILE*);
194
195/* These are referenced by the Greed for Glory franchise. */
196__LIBC32_LEGACY_PUBLIC__ int __sflush(FILE *);
197__LIBC32_LEGACY_PUBLIC__ int __sread(void *, char *, int);
198__LIBC32_LEGACY_PUBLIC__ int __swrite(void *, const char *, int);
199__LIBC32_LEGACY_PUBLIC__ fpos_t __sseek(void *, fpos_t, int);
200__LIBC32_LEGACY_PUBLIC__ int __sclose(void *);
201__LIBC32_LEGACY_PUBLIC__ int _fwalk(int (*)(FILE *));
202
203#pragma GCC visibility push(hidden)
204
205off64_t __sseek64(void*, off64_t, int);
206int	__sflush_locked(FILE *);
207int	__swhatbuf(FILE *, size_t *, int *);
208wint_t __fgetwc_unlock(FILE *);
209wint_t	__ungetwc(wint_t, FILE *);
210int	__vfprintf(FILE *, const char *, __va_list);
211int	__svfscanf(FILE * __restrict, const char * __restrict, __va_list);
212int	__vfwprintf(FILE * __restrict, const wchar_t * __restrict, __va_list);
213int	__vfwscanf(FILE * __restrict, const wchar_t * __restrict, __va_list);
214
215/*
216 * Return true if the given FILE cannot be written now.
217 */
218#define	cantwrite(fp) \
219	((((fp)->_flags & __SWR) == 0 || (fp)->_bf._base == NULL) && \
220	 __swsetup(fp))
221
222/*
223 * Test whether the given stdio file has an active ungetc buffer;
224 * release such a buffer, without restoring ordinary unread data.
225 */
226#define	HASUB(fp) (_UB(fp)._base != NULL)
227#define	FREEUB(fp) { \
228	if (_UB(fp)._base != (fp)->_ubuf) \
229		free(_UB(fp)._base); \
230	_UB(fp)._base = NULL; \
231}
232
233/*
234 * test for an fgetln() buffer.
235 */
236#define	HASLB(fp) ((fp)->_lb._base != NULL)
237#define	FREELB(fp) { \
238	free((char *)(fp)->_lb._base); \
239	(fp)->_lb._base = NULL; \
240}
241
242#define FLOCKFILE(fp)   if (!_EXT(fp)->_caller_handles_locking) flockfile(fp)
243#define FUNLOCKFILE(fp) if (!_EXT(fp)->_caller_handles_locking) funlockfile(fp)
244
245#define FLOATING_POINT
246#define PRINTF_WIDE_CHAR
247#define SCANF_WIDE_CHAR
248#define NO_PRINTF_PERCENT_N
249
250/* OpenBSD exposes these in <stdio.h>, but we only want them exposed to the implementation. */
251#define __sfeof(p)     (((p)->_flags & __SEOF) != 0)
252#define __sferror(p)   (((p)->_flags & __SERR) != 0)
253#define __sclearerr(p) ((void)((p)->_flags &= ~(__SERR|__SEOF)))
254#if !defined(__cplusplus)
255#define __sgetc(p) (--(p)->_r < 0 ? __srget(p) : (int)(*(p)->_p++))
256static __inline int __sputc(int _c, FILE* _p) {
257  if (--_p->_w >= 0 || (_p->_w >= _p->_lbfsize && (char)_c != '\n')) {
258    return (*_p->_p++ = _c);
259  } else {
260    return (__swbuf(_c, _p));
261  }
262}
263#endif
264
265/* OpenBSD declares these in fvwrite.h but we want to ensure they're hidden. */
266struct __suio;
267extern int __sfvwrite(FILE *, struct __suio *);
268wint_t __fputwc_unlock(wchar_t wc, FILE *fp);
269
270/* Remove the if (!__sdidinit) __sinit() idiom from untouched upstream stdio code. */
271extern void __sinit(void); // Not actually implemented.
272#define __sdidinit 1
273
274#pragma GCC visibility pop
275
276__END_DECLS
277
278#endif
279