libc/stdio/local.h - platform/bionic - Git at Google

 /*	$OpenBSD: local.h,v 1.12 2005/10/10 17:37:44 espie Exp $	*/

 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * Chris Torek.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */

 #pragma once

 #include <pthread.h>
 #include <stdbool.h>
 #include <wchar.h>

 #if defined(__cplusplus)  // Until we fork all of stdio...
 #include "private/bionic_fortify.h"
 #endif

 /*
  * Information local to this implementation of stdio,
  * in particular, macros and private variables.
  */

 __BEGIN_DECLS

 struct __sbuf {
   unsigned char* _base;
   size_t _size;
 };

 struct __sFILE {
   unsigned char* _p; /* current position in (some) buffer */
   int _r;            /* read space left for getc() */
   int _w;            /* write space left for putc() */
 #if defined(__LP64__)
   int _flags; /* flags, below; this FILE is free if 0 */
   int _file;  /* fileno, if Unix descriptor, else -1 */
 #else
   short _flags; /* flags, below; this FILE is free if 0 */
   short _file;  /* fileno, if Unix descriptor, else -1 */
 #endif
   struct __sbuf _bf; /* the buffer (at least 1 byte, if !NULL) */
   int _lbfsize;      /* 0 or -_bf._size, for inline putc */

   // Function pointers used by `funopen`.
   // Note that `_seek` is ignored if `_seek64` (in __sfileext) is set.
   // TODO: NetBSD has `funopen2` which corrects the `int`s to `size_t`s.
   // TODO: glibc has `fopencookie` which passes the function pointers in a struct.
   void* _cookie; /* cookie passed to io functions */
   int (*_close)(void*);
   int (*_read)(void*, char*, int);
   fpos_t (*_seek)(void*, fpos_t, int);
   int (*_write)(void*, const char*, int);

   /* extension data, to avoid further ABI breakage */
   struct __sbuf _ext;
   /* data for long sequences of ungetc() */
   unsigned char* _up; /* saved _p when _p is doing ungetc data */
   int _ur;            /* saved _r when _r is counting ungetc data */

   /* tricks to meet minimum requirements even when malloc() fails */
   unsigned char _ubuf[3]; /* guarantee an ungetc() buffer */
   unsigned char _nbuf[1]; /* guarantee a getc() buffer */

   /* separate buffer for fgetln() when line crosses buffer boundary */
   struct __sbuf _lb; /* buffer for fgetln() */

   /* Unix stdio files get aligned to block boundaries on fseek() */
   int _blksize; /* stat.st_blksize (may be != _bf._size) */

   fpos_t _unused_0;  // This was the `_offset` field (see below).

   // Do not add new fields here. (Or remove or change the size of any above.)
   // Although bionic currently exports `stdin`, `stdout`, and `stderr` symbols,
   // that still hasn't made it to the NDK. All NDK-built apps index directly
   // into an array of this struct (which was in <stdio.h> historically), so if
   // you need to make any changes, they need to be in the `__sfileext` struct
   // below, and accessed via `_EXT`.
 };

 /* minimal requirement of SUSv2 */
 #define WCIO_UNGETWC_BUFSIZE 1

 struct wchar_io_data {
   mbstate_t wcio_mbstate_in;
   mbstate_t wcio_mbstate_out;

   wchar_t wcio_ungetwc_buf[WCIO_UNGETWC_BUFSIZE];
   size_t wcio_ungetwc_inbuf;

   int wcio_mode; /* orientation */
 };

 struct __sfileext {
   // ungetc buffer.
   struct __sbuf _ub;

   // Wide char io status.
   struct wchar_io_data _wcio;

   // File lock.
   pthread_mutex_t _lock;

   // __fsetlocking support.
   bool _caller_handles_locking;

   // Equivalent to `_seek` but for _FILE_OFFSET_BITS=64.
   // Callers should use this but fall back to `__sFILE::_seek`.
   off64_t (*_seek64)(void*, off64_t, int);

   // The pid of the child if this FILE* is from popen(3).
   pid_t _popen_pid;
 };

 // Values for `__sFILE::_flags`.
 #define __SLBF 0x0001  // Line buffered.
 #define __SNBF 0x0002  // Unbuffered.
 // __SRD and __SWR are mutually exclusive because they indicate what we did last.
 // If you want to know whether we were opened read-write, check __SRW instead.
 #define __SRD 0x0004   // Last operation was read.
 #define __SWR 0x0008   // Last operation was write.
 #define __SRW 0x0010   // Was opened for reading & writing.
 #define __SEOF 0x0020  // Found EOF.
 #define __SERR 0x0040  // Found error.
 #define __SMBF 0x0080  // `_buf` is from malloc.
 // #define __SAPP 0x0100 --- historical (fdopen()ed in append mode).
 #define __SSTR 0x0200  // This is an sprintf/snprintf string.
 // #define __SOPT 0x0400 --- historical (do fseek() optimization).
 // #define __SNPT 0x0800 --- historical (do not do fseek() optimization).
 // #define __SOFF 0x1000 --- historical (set iff _offset is in fact correct).
 // #define __SMOD 0x2000 --- historical (set iff fgetln modified _p text).
 #define __SALC 0x4000  // Allocate string space dynamically.
 #define __SIGN 0x8000  // Ignore this file in _fwalk.

 // TODO: remove remaining references to these obsolete flags (see above).
 #define __SMOD 0
 #define __SNPT 0
 #define __SOPT 0

 #define _EXT(fp) __BIONIC_CAST(reinterpret_cast, struct __sfileext*, (fp)->_ext._base)

 #define _UB(fp) _EXT(fp)->_ub

 #define _FILEEXT_SETUP(fp, fext)                                              \
   do {                                                                        \
     (fp)->_ext._base = __BIONIC_CAST(reinterpret_cast, unsigned char*, fext); \
     memset(_EXT(fp), 0, sizeof(struct __sfileext));                           \
     _EXT(fp)->_caller_handles_locking = true;                                 \
   } while (0)

 // Android <= 19 had getc/putc macros in <stdio.h> that referred
 // to __srget/__swbuf, so those symbols need to be public for LP32
 // but can be hidden for LP64. Moreover, the NDK continued to ship
 // those macros until r15 made unified headers the default.
 __LIBC32_LEGACY_PUBLIC__ int __srget(FILE*);
 __LIBC32_LEGACY_PUBLIC__ int __swbuf(int, FILE*);
 __LIBC32_LEGACY_PUBLIC__ int __srefill(FILE*);

 /* This was referenced by the apportable middleware for LP32. */
 __LIBC32_LEGACY_PUBLIC__ int __swsetup(FILE*);

 /* These were referenced by a couple of different pieces of middleware and the Crystax NDK. */
 __LIBC32_LEGACY_PUBLIC__ int __sflags(const char*, int*);
 __LIBC32_LEGACY_PUBLIC__ FILE* __sfp(void);
 __LIBC32_LEGACY_PUBLIC__ void __smakebuf(FILE*);

 /* These are referenced by the Greed for Glory franchise. */
 __LIBC32_LEGACY_PUBLIC__ int __sflush(FILE*);
 __LIBC32_LEGACY_PUBLIC__ int __sread(void*, char*, int);
 __LIBC32_LEGACY_PUBLIC__ int __swrite(void*, const char*, int);
 __LIBC32_LEGACY_PUBLIC__ fpos_t __sseek(void*, fpos_t, int);
 __LIBC32_LEGACY_PUBLIC__ int __sclose(void*);
 __LIBC32_LEGACY_PUBLIC__ int _fwalk(int (*)(FILE*));

 off64_t __sseek64(void*, off64_t, int);
 int __sflush_locked(FILE*);
 int __swhatbuf(FILE*, size_t*, int*);
 wint_t __fgetwc_unlock(FILE*);
 wint_t __ungetwc(wint_t, FILE*);
 int __vfprintf(FILE*, const char*, va_list);
 int __svfscanf(FILE*, const char*, va_list);
 int __vfwprintf(FILE*, const wchar_t*, va_list);
 int __vfwscanf(FILE*, const wchar_t*, va_list);

 /*
  * Return true if the given FILE cannot be written now.
  */
 #define cantwrite(fp) ((((fp)->_flags & __SWR) == 0 || (fp)->_bf._base == NULL) && __swsetup(fp))

 /*
  * Test whether the given stdio file has an active ungetc buffer;
  * release such a buffer, without restoring ordinary unread data.
  */
 #define HASUB(fp) (_UB(fp)._base != NULL)
 #define FREEUB(fp)                                         \
   {                                                        \
     if (_UB(fp)._base != (fp)->_ubuf) free(_UB(fp)._base); \
     _UB(fp)._base = NULL;                                  \
   }

 #define FLOCKFILE(fp) \
   if (!_EXT(fp)->_caller_handles_locking) flockfile(fp)
 #define FUNLOCKFILE(fp) \
   if (!_EXT(fp)->_caller_handles_locking) funlockfile(fp)

 /* OpenBSD exposes these in <stdio.h>, but we only want them exposed to the implementation. */
 #define __sferror(p) (((p)->_flags & __SERR) != 0)
 #define __sclearerr(p) ((void)((p)->_flags &= ~(__SERR | __SEOF)))
 #define __sgetc(p) (--(p)->_r < 0 ? __srget(p) : __BIONIC_CAST(static_cast, int, *(p)->_p++))

 /* OpenBSD declares these in fvwrite.h, but we share them with C++ parts of the implementation. */
 struct __siov {
   void* iov_base;
   size_t iov_len;
 };
 struct __suio {
   struct __siov* uio_iov;
   int uio_iovcnt;
   size_t uio_resid;
 };
 int __sfvwrite(FILE*, struct __suio*);
 wint_t __fputwc_unlock(wchar_t wc, FILE* fp);

 /* Remove the if (!__sdidinit) __sinit() idiom from untouched upstream stdio code. */
 extern void __sinit(void);  // Not actually implemented.
 #define __sdidinit 1

 size_t parsefloat(FILE*, char*, char*);
 size_t wparsefloat(FILE*, wchar_t*, wchar_t*);

 // Check a FILE* isn't nullptr, so we can emit a clear diagnostic message
 // instead of just crashing with SIGSEGV.
 #define CHECK_FP(fp) \
   if (fp == nullptr) __fortify_fatal("%s: null FILE*", __FUNCTION__)

 /*
  * Floating point scanf/printf (input/output) definitions.
  */

 /* 11-bit exponent (VAX G floating point) is 308 decimal digits */
 #define MAXEXP 308
 /* 128 bit fraction takes up 39 decimal digits; max reasonable precision */
 #define MAXFRACT 39

 /*
  * MAXEXPDIG is the maximum number of decimal digits needed to store a
  * floating point exponent in the largest supported format.  It should
  * be ceil(log10(LDBL_MAX_10_EXP)) or, if hexadecimal floating point
  * conversions are supported, ceil(log10(LDBL_MAX_EXP)).  But since it
  * is presently never greater than 5 in practice, we fudge it.
  */
 #define MAXEXPDIG 6
 #if LDBL_MAX_EXP > 999999
 #error "floating point buffers too small"
 #endif

 char* __hdtoa(double, const char*, int, int*, int*, char**);
 char* __hldtoa(long double, const char*, int, int*, int*, char**);
 char* __ldtoa(long double*, int, int, int*, int*, char**);

 #define WCIO_GET(fp) (_EXT(fp) ? &(_EXT(fp)->_wcio) : NULL)

 #define ORIENT_BYTES (-1)
 #define ORIENT_UNKNOWN 0
 #define ORIENT_CHARS 1

 #define _SET_ORIENTATION(fp, mode)                                              \
   do {                                                                          \
     struct wchar_io_data* _wcio = WCIO_GET(fp);                                 \
     if (_wcio && _wcio->wcio_mode == ORIENT_UNKNOWN) _wcio->wcio_mode = (mode); \
   } while (0)

 #define WCIO_FREE(fp)                           \
   do {                                          \
     struct wchar_io_data* _wcio = WCIO_GET(fp); \
     if (_wcio) {                                \
       _wcio->wcio_mode = ORIENT_UNKNOWN;        \
       _wcio->wcio_ungetwc_inbuf = 0;            \
     }                                           \
   } while (0)

 __END_DECLS
	/* $OpenBSD: local.h,v 1.12 2005/10/10 17:37:44 espie Exp $ */

	/*-
	* Copyright (c) 1990, 1993
	* The Regents of the University of California. All rights reserved.
	*
	* This code is derived from software contributed to Berkeley by
	* Chris Torek.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the name of the University nor the names of its contributors
	* may be used to endorse or promote products derived from this software
	* without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*/

	#pragma once

	#include <pthread.h>
	#include <stdbool.h>
	#include <wchar.h>

	#if defined(__cplusplus) // Until we fork all of stdio...
	#include "private/bionic_fortify.h"
	#endif

	/*
	* Information local to this implementation of stdio,
	* in particular, macros and private variables.
	*/

	__BEGIN_DECLS

	struct __sbuf {
	unsigned char* _base;
	size_t _size;
	};

	struct __sFILE {
	unsigned char* _p; /* current position in (some) buffer */
	int _r; /* read space left for getc() */
	int _w; /* write space left for putc() */
	#if defined(__LP64__)
	int _flags; /* flags, below; this FILE is free if 0 */
	int _file; /* fileno, if Unix descriptor, else -1 */
	#else
	short _flags; /* flags, below; this FILE is free if 0 */
	short _file; /* fileno, if Unix descriptor, else -1 */
	#endif
	struct __sbuf _bf; /* the buffer (at least 1 byte, if !NULL) */
	int _lbfsize; /* 0 or -_bf._size, for inline putc */

	// Function pointers used by `funopen`.
	// Note that `_seek` is ignored if `_seek64` (in __sfileext) is set.
	// TODO: NetBSD has `funopen2` which corrects the `int`s to `size_t`s.
	// TODO: glibc has `fopencookie` which passes the function pointers in a struct.
	void* _cookie; /* cookie passed to io functions */
	int (_close)(void);
	int (_read)(void, char*, int);
	fpos_t (_seek)(void, fpos_t, int);
	int (_write)(void, const char*, int);

	/* extension data, to avoid further ABI breakage */
	struct __sbuf _ext;
	/* data for long sequences of ungetc() */
	unsigned char* _up; /* saved _p when _p is doing ungetc data */
	int _ur; /* saved _r when _r is counting ungetc data */

	/* tricks to meet minimum requirements even when malloc() fails */
	unsigned char _ubuf[3]; /* guarantee an ungetc() buffer */
	unsigned char _nbuf[1]; /* guarantee a getc() buffer */

	/* separate buffer for fgetln() when line crosses buffer boundary */
	struct __sbuf _lb; /* buffer for fgetln() */

	/* Unix stdio files get aligned to block boundaries on fseek() */
	int _blksize; /* stat.st_blksize (may be != _bf._size) */

	fpos_t _unused_0; // This was the `_offset` field (see below).

	// Do not add new fields here. (Or remove or change the size of any above.)
	// Although bionic currently exports `stdin`, `stdout`, and `stderr` symbols,
	// that still hasn't made it to the NDK. All NDK-built apps index directly
	// into an array of this struct (which was in <stdio.h> historically), so if
	// you need to make any changes, they need to be in the `__sfileext` struct
	// below, and accessed via `_EXT`.
	};

	/* minimal requirement of SUSv2 */
	#define WCIO_UNGETWC_BUFSIZE 1

	struct wchar_io_data {
	mbstate_t wcio_mbstate_in;
	mbstate_t wcio_mbstate_out;

	wchar_t wcio_ungetwc_buf[WCIO_UNGETWC_BUFSIZE];
	size_t wcio_ungetwc_inbuf;

	int wcio_mode; /* orientation */
	};

	struct __sfileext {
	// ungetc buffer.
	struct __sbuf _ub;

	// Wide char io status.
	struct wchar_io_data _wcio;

	// File lock.
	pthread_mutex_t _lock;

	// __fsetlocking support.
	bool _caller_handles_locking;

	// Equivalent to `_seek` but for _FILE_OFFSET_BITS=64.
	// Callers should use this but fall back to `__sFILE::_seek`.
	off64_t (_seek64)(void, off64_t, int);

	// The pid of the child if this FILE* is from popen(3).
	pid_t _popen_pid;
	};

	// Values for `__sFILE::_flags`.
	#define __SLBF 0x0001 // Line buffered.
	#define __SNBF 0x0002 // Unbuffered.
	// __SRD and __SWR are mutually exclusive because they indicate what we did last.
	// If you want to know whether we were opened read-write, check __SRW instead.
	#define __SRD 0x0004 // Last operation was read.
	#define __SWR 0x0008 // Last operation was write.
	#define __SRW 0x0010 // Was opened for reading & writing.
	#define __SEOF 0x0020 // Found EOF.
	#define __SERR 0x0040 // Found error.
	#define __SMBF 0x0080 // `_buf` is from malloc.
	// #define __SAPP 0x0100 --- historical (fdopen()ed in append mode).
	#define __SSTR 0x0200 // This is an sprintf/snprintf string.
	// #define __SOPT 0x0400 --- historical (do fseek() optimization).
	// #define __SNPT 0x0800 --- historical (do not do fseek() optimization).
	// #define __SOFF 0x1000 --- historical (set iff _offset is in fact correct).
	// #define __SMOD 0x2000 --- historical (set iff fgetln modified _p text).
	#define __SALC 0x4000 // Allocate string space dynamically.
	#define __SIGN 0x8000 // Ignore this file in _fwalk.

	// TODO: remove remaining references to these obsolete flags (see above).
	#define __SMOD 0
	#define __SNPT 0
	#define __SOPT 0

	#define _EXT(fp) __BIONIC_CAST(reinterpret_cast, struct __sfileext*, (fp)->_ext._base)

	#define _UB(fp) _EXT(fp)->_ub

	#define _FILEEXT_SETUP(fp, fext) \
	do { \
	(fp)->_ext._base = __BIONIC_CAST(reinterpret_cast, unsigned char*, fext); \
	memset(_EXT(fp), 0, sizeof(struct __sfileext)); \
	_EXT(fp)->_caller_handles_locking = true; \
	} while (0)

	// Android <= 19 had getc/putc macros in <stdio.h> that referred
	// to __srget/__swbuf, so those symbols need to be public for LP32
	// but can be hidden for LP64. Moreover, the NDK continued to ship
	// those macros until r15 made unified headers the default.
	__LIBC32_LEGACY_PUBLIC__ int __srget(FILE*);
	__LIBC32_LEGACY_PUBLIC__ int __swbuf(int, FILE*);
	__LIBC32_LEGACY_PUBLIC__ int __srefill(FILE*);

	/* This was referenced by the apportable middleware for LP32. */
	__LIBC32_LEGACY_PUBLIC__ int __swsetup(FILE*);

	/* These were referenced by a couple of different pieces of middleware and the Crystax NDK. */
	__LIBC32_LEGACY_PUBLIC__ int __sflags(const char, int);
	__LIBC32_LEGACY_PUBLIC__ FILE* __sfp(void);
	__LIBC32_LEGACY_PUBLIC__ void __smakebuf(FILE*);

	/* These are referenced by the Greed for Glory franchise. */
	__LIBC32_LEGACY_PUBLIC__ int __sflush(FILE*);
	__LIBC32_LEGACY_PUBLIC__ int __sread(void, char, int);
	__LIBC32_LEGACY_PUBLIC__ int __swrite(void, const char, int);
	__LIBC32_LEGACY_PUBLIC__ fpos_t __sseek(void*, fpos_t, int);
	__LIBC32_LEGACY_PUBLIC__ int __sclose(void*);
	__LIBC32_LEGACY_PUBLIC__ int _fwalk(int ()(FILE));

	off64_t __sseek64(void*, off64_t, int);
	int __sflush_locked(FILE*);
	int __swhatbuf(FILE, size_t, int*);
	wint_t __fgetwc_unlock(FILE*);
	wint_t __ungetwc(wint_t, FILE*);
	int __vfprintf(FILE, const char, va_list);
	int __svfscanf(FILE, const char, va_list);
	int __vfwprintf(FILE, const wchar_t, va_list);
	int __vfwscanf(FILE, const wchar_t, va_list);

	/*
	* Return true if the given FILE cannot be written now.
	*/
	#define cantwrite(fp) ((((fp)->_flags & __SWR) == 0 \|\| (fp)->_bf._base == NULL) && __swsetup(fp))

	/*
	* Test whether the given stdio file has an active ungetc buffer;
	* release such a buffer, without restoring ordinary unread data.
	*/
	#define HASUB(fp) (_UB(fp)._base != NULL)
	#define FREEUB(fp) \
	{ \
	if (_UB(fp)._base != (fp)->_ubuf) free(_UB(fp)._base); \
	_UB(fp)._base = NULL; \
	}

	#define FLOCKFILE(fp) \
	if (!_EXT(fp)->_caller_handles_locking) flockfile(fp)
	#define FUNLOCKFILE(fp) \
	if (!_EXT(fp)->_caller_handles_locking) funlockfile(fp)

	/* OpenBSD exposes these in <stdio.h>, but we only want them exposed to the implementation. */
	#define __sferror(p) (((p)->_flags & __SERR) != 0)
	#define __sclearerr(p) ((void)((p)->_flags &= ~(__SERR \| __SEOF)))
	#define __sgetc(p) (--(p)->_r < 0 ? __srget(p) : __BIONIC_CAST(static_cast, int, *(p)->_p++))

	/* OpenBSD declares these in fvwrite.h, but we share them with C++ parts of the implementation. */
	struct __siov {
	void* iov_base;
	size_t iov_len;
	};
	struct __suio {
	struct __siov* uio_iov;
	int uio_iovcnt;
	size_t uio_resid;
	};
	int __sfvwrite(FILE, struct __suio);
	wint_t __fputwc_unlock(wchar_t wc, FILE* fp);

	/* Remove the if (!__sdidinit) __sinit() idiom from untouched upstream stdio code. */
	extern void __sinit(void); // Not actually implemented.
	#define __sdidinit 1

	size_t parsefloat(FILE, char, char*);
	size_t wparsefloat(FILE, wchar_t, wchar_t*);

	// Check a FILE* isn't nullptr, so we can emit a clear diagnostic message
	// instead of just crashing with SIGSEGV.
	#define CHECK_FP(fp) \
	if (fp == nullptr) __fortify_fatal("%s: null FILE*", __FUNCTION__)

	/*
	* Floating point scanf/printf (input/output) definitions.
	*/

	/* 11-bit exponent (VAX G floating point) is 308 decimal digits */
	#define MAXEXP 308
	/* 128 bit fraction takes up 39 decimal digits; max reasonable precision */
	#define MAXFRACT 39

	/*
	* MAXEXPDIG is the maximum number of decimal digits needed to store a
	* floating point exponent in the largest supported format. It should
	* be ceil(log10(LDBL_MAX_10_EXP)) or, if hexadecimal floating point
	* conversions are supported, ceil(log10(LDBL_MAX_EXP)). But since it
	* is presently never greater than 5 in practice, we fudge it.
	*/
	#define MAXEXPDIG 6
	#if LDBL_MAX_EXP > 999999
	#error "floating point buffers too small"
	#endif

	char* __hdtoa(double, const char, int, int, int, char*);
	char* __hldtoa(long double, const char, int, int, int, char*);
	char* __ldtoa(long double, int, int, int, int, char*);

	#define WCIO_GET(fp) (_EXT(fp) ? &(_EXT(fp)->_wcio) : NULL)

	#define ORIENT_BYTES (-1)
	#define ORIENT_UNKNOWN 0
	#define ORIENT_CHARS 1

	#define _SET_ORIENTATION(fp, mode) \
	do { \
	struct wchar_io_data* _wcio = WCIO_GET(fp); \
	if (_wcio && _wcio->wcio_mode == ORIENT_UNKNOWN) _wcio->wcio_mode = (mode); \
	} while (0)

	#define WCIO_FREE(fp) \
	do { \
	struct wchar_io_data* _wcio = WCIO_GET(fp); \
	if (_wcio) { \
	_wcio->wcio_mode = ORIENT_UNKNOWN; \
	_wcio->wcio_ungetwc_inbuf = 0; \
	} \
	} while (0)

	__END_DECLS