uclibc_stdio.h

它通过提供glibc兼容使得应用程序移植到较小的c 库时相当得容易. 它能够应用到带虚拟存储的Linux和uClinux上.在大多数带MMU部件的平台上为使它更加紧凑,它也能够编译成共享库.uClib

/*  Copyright (C) 2002     Manuel Novoa III
 *  Header for my stdio library for linux and (soon) elks.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*  ATTENTION!   ATTENTION!   ATTENTION!   ATTENTION!   ATTENTION!
 *
 *  This code is currently under development.  Also, I plan to port
 *  it to elks which is a 16-bit environment with a fairly limited
 *  compiler.  Therefore, please refrain from modifying this code
 *  and, instead, pass any bug-fixes, etc. to me.  Thanks.  Manuel
 *
 *  ATTENTION!   ATTENTION!   ATTENTION!   ATTENTION!   ATTENTION! */

#ifndef _STDIO_H
#error Always include <stdio.h> rather than <bits/uClibc_stdio.h>
#endif

/**********************************************************************/
#ifdef __UCLIBC__

#ifdef __UCLIBC_HAS_THREADS__
#define __STDIO_THREADSAFE
#endif

#ifdef __UCLIBC_HAS_LFS__
#define __STDIO_LARGE_FILES
#endif /* __UCLIBC_HAS_LFS__ */

#ifdef __UCLIBC_HAS_WCHAR__
#define __STDIO_WIDE
#endif

/* Make sure defines related to large files are consistent. */
#ifdef _LIBC

#ifdef __UCLIBC_HAS_LFS__
#undef __USE_LARGEFILE
#undef __USE_LARGEFILE64
#undef __USE_FILE_OFFSET64
/* if we're actually building uClibc with large file support, only define... */
#define __USE_LARGEFILE64	1
#endif /* __UCLIBC_HAS_LFS__ */

#else  /* not _LIBC */

#ifndef __UCLIBC_HAS_LFS__
#if defined(__LARGEFILE64_SOURCE) || defined(__USE_LARGEFILE64) \
    || defined(__USE_FILE_OFFSET64)
#error Sorry... uClibc was built without large file support!
#endif
#endif /* __UCLIBC_HAS_LFS__ */

#endif /* _LIBC */

#endif /* __UCLIBC__ */
/**********************************************************************/
/* These are the stdio configuration options.  Keep them here until
   uClibc's configuration process gets reworked. */

#ifdef __STDIO_WIDE
#define __need_wchar_t
#include <stddef.h>
/* Note: we don't really need mbstate for 8-bit locales.  We do for UTF-8.
 * For now, always use it. */
#define __STDIO_MBSTATE
#define __need_mbstate_t
#include <wchar.h>
#endif

#define __STDIO_BUFFERS
#define __STDIO_GETC_MACRO
#define __STDIO_PUTC_MACRO

/* For uClibc, these are currently handled above. */
/*  #define __STDIO_LARGE_FILES */
/*  #define __STDIO_THREADSAFE */

/* L mode extension for fopen. */
#define __STDIO_FOPEN_LARGEFILE_MODE

/* size of builtin buf -- only tested with 0 */
#define _STDIO_BUILTIN_BUF_SIZE		0

/* TODO - enable features based on __STDIO_GLIBC_FEATURES */

/*  #define __STDIO_GLIBC_FEATURES */
#define __STDIO_AUTO_RW_TRANSITION
#define __STDIO_FOPEN_EXCLUSIVE_MODE
#define __STDIO_PRINTF_M_SPEC
#define __STDIO_GLIBC_CUSTOM_STREAMS


/* ANSI/ISO mandate at least 256. */
#define _STDIO_BUFSIZ			256

/* Currently unimplemented/untested */
/* #define __STDIO_FLEXIBLE_SETVBUF */

/**********************************************************************/
/* TODO -- posix or gnu -- belongs in limits.h and >= 9 for sus */
/* NOTE: for us it is currently _always_ 9 */
/*#define NL_ARGMAX			9*/

/**********************************************************************/

/* These are consistency checks on the different options */

#ifndef __STDIO_BUFFERS
#undef __STDIO_GETC_MACRO
#undef __STDIO_PUTC_MACRO
#endif

#ifdef __BCC__
#undef __STDIO_LARGE_FILES
#endif

#ifndef __STDIO_LARGE_FILES
#undef __STDIO_FOPEN_LARGEFILE_MODE
#endif

/**********************************************************************/

#ifdef __STDIO_THREADSAFE
/* Need this for pthread_mutex_t. */
#include <bits/pthreadtypes.h>

#define __STDIO_THREADLOCK(STREAM) \
	if ((STREAM)->user_locking == 0) { \
		pthread_mutex_lock(&(STREAM)->lock); \
	}

#define __STDIO_THREADUNLOCK(STREAM) \
	if ((STREAM)->user_locking == 0) { \
		pthread_mutex_unlock(&(STREAM)->lock); \
	}

#define __STDIO_THREADTRYLOCK(STREAM) \
	if ((STREAM)->user_locking == 0) { \
		pthread_mutex_trylock(&(STREAM)->lock); \
	}

#else  /* __STDIO_THREADSAFE */

#define __STDIO_THREADLOCK(STREAM)
#define __STDIO_THREADUNLOCK(STREAM)
#define __STDIO_THREADTRYLOCK(STREAM)

#endif /* __STDIO_THREADSAFE */

/* This file may eventually have two personalities:
   1) core stuff (similar to glibc's libio.h)
   2) extern inlines (for glibc's bits/stdio.h)
   Right now, only (1) is implemented. */

#define _STDIO_IOFBF 0	/* Fully buffered.  */
#define _STDIO_IOLBF 1	/* Line buffered.  */
#define _STDIO_IONBF 2	/* No buffering.  */

typedef struct {
	__off_t __pos;
#ifdef __STDIO_MBSTATE
  __mbstate_t __mbstate;
#endif
} __stdio_fpos_t;

#ifdef __STDIO_LARGE_FILES
typedef struct {
	__off64_t __pos;
#ifdef __STDIO_MBSTATE
  __mbstate_t __mbstate;
#endif
} __stdio_fpos64_t;
#endif


/**********************************************************************/
#ifdef __STDIO_LARGE_FILES
typedef __off64_t __offmax_t;	/* TODO -- rename this? */
#else
typedef __off_t __offmax_t;		/* TODO -- rename this? */
#endif

/**********************************************************************/

#ifdef __STDIO_GLIBC_CUSTOM_STREAMS

typedef __ssize_t __io_read_fn(void *cookie,
							   char *buf, size_t bufsize);
typedef __ssize_t __io_write_fn(void *cookie,
								const char *buf, size_t bufsize);
/* NOTE: GLIBC difference!!! -- fopencookie seek function
 * For glibc, the type of pos is always (__off64_t *) but in our case
 * it is type (__off_t *) when the lib is built without large file support.
 */
typedef int __io_seek_fn(void *cookie,
						 __offmax_t *pos, int whence);
typedef int __io_close_fn(void *cookie);

typedef struct {
	__io_read_fn *read;
	__io_write_fn *write;
	__io_seek_fn *seek;
	__io_close_fn *close;
} _IO_cookie_io_functions_t;

#if defined(_LIBC) || defined(_GNU_SOURCE)
typedef __io_read_fn cookie_read_function_t;
typedef __io_write_fn cookie_write_function_t;
typedef __io_seek_fn cookie_seek_function_t;
typedef __io_close_fn cookie_close_function_t;

typedef _IO_cookie_io_functions_t cookie_io_functions_t;
#endif /* _GNU_SOURCE */

#endif /* __STDIO_GLIBC_CUSTOM_STREAMS */

/*
 * ungot scheme:
 * 0 0   none
 * 0 1   one user (unused ungot is 1) or one scanf (unused ungot is 0)
 * 1 0   must be scanf[0] and user[1]
 * 1 1   illegal -- could be used to signal safe for setbuf
 */

#ifdef __UCLIBC__
#define __stdio_file_struct _UC_FILE
#endif

struct __stdio_file_struct {
	unsigned short modeflags;
	/* There could be a hole here, but modeflags is used most.*/
#ifdef __STDIO_WIDE
	/* TOOD - ungot_width could be combined with ungot.  But what about hole? */
	unsigned char ungot_width[2];
	wchar_t ungot[2];
#else  /* __STDIO_WIDE */
	unsigned char ungot[2];
#endif /* __STDIO_WIDE */
	int filedes;
#if defined(__STDIO_BUFFERS) || defined(__STDIO_GLIBC_CUSTOM_STREAMS)
	struct __stdio_file_struct *nextopen;
#endif /* defined(__STDIO_BUFFERS) || defined(__STDIO_GLIBC_CUSTOM_STREAMS) */
#ifdef __STDIO_BUFFERS
	unsigned char *bufstart;	/* pointer to buffer */
	unsigned char *bufend;		/* pointer to 1 past end of buffer */
	unsigned char *bufpos;
	unsigned char *bufread;		/* pointer to 1 past last buffered read char. */
#ifdef __STDIO_GETC_MACRO
	unsigned char *bufgetc;		/* 1 past last readable by getc */
#endif /* __STDIO_GETC_MACRO */