stdstrbufs.cpp

vxworks源码源码解读是学习vxworks的最佳途径

/* This has been copied from the gnu source tree */
/* Make all changes there, not here! */
#ifdef __cplusplus
extern "C" {
#endif
#ifndef _N_
char __stdstrbufs_o = 0;
#else
char _N_ = 0;
#endif
#ifdef __cplusplus
}
#endif
#include "vxWorks.h"
/*
Copyright (C) 1994 Free Software Foundation

This file is part of the GNU IO Library.  This library is free
software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this library; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

As a special exception, if you link this library with files
compiled with a GNU compiler to produce an executable, this does not cause
the resulting executable to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why
the executable file might be covered by the GNU General Public License. */


/* This file provides definitions of _IO_stdin, _IO_stdout, and _IO_stderr
   for C++ code.  Compare stdfiles.c.
   (The difference is that here the vtable field is set to
   point to builtinbuf's vtable, so the objects are effectively
   of class builtinbuf.) */

#include "libioP.h"
#include <stdio.h>

#if !defined(filebuf_vtable) && defined(__cplusplus)
#ifdef __GNUC__
extern char filebuf_vtable[]
  asm (_G_VTABLE_LABEL_PREFIX
#if _G_VTABLE_LABEL_HAS_LENGTH
       "7"
#endif
       "filebuf");
#else /* !__GNUC__ */
#if _G_VTABLE_LABEL_HAS_LENGTH
#define filebuf_vtable _G_VTABLE_LABEL_PREFIX_ID##7filebuf
#else
#define filebuf_vtable _G_VTABLE_LABEL_PREFIX_ID##filebuf
#endif
extern char filebuf_vtable[];
#endif /* !__GNUC__ */
#endif /* !defined(filebuf_vtable) && defined(__cplusplus) */

#ifndef STD_VTABLE
#define STD_VTABLE (const struct _IO_jump_t *)filebuf_vtable
#endif

#ifdef _IO_MTSAFE_IO
#define DEF_STDFILE(NAME, FD, CHAIN, FLAGS) \
  static _IO_lock_t _IO_stdfile_##FD##_lock = _IO_lock_initializer; \
  struct _IO_FILE_plus NAME \
    = {FILEBUF_LITERAL(CHAIN, FLAGS, FD), STD_VTABLE}
#else
#define DEF_STDFILE(NAME, FD, CHAIN, FLAGS) \
  struct _IO_FILE_plus NAME = {FILEBUF_LITERAL(CHAIN, FLAGS, FD), STD_VTABLE}
#endif

DEF_STDFILE(_IO_stdin_, 0, 0, _IO_NO_WRITES);
DEF_STDFILE(_IO_stdout_, 1, &_IO_stdin_.file, _IO_NO_READS);
DEF_STDFILE(_IO_stderr_, 2, &_IO_stdout_.file,
            _IO_NO_READS+_IO_UNBUFFERED);

/* Begin VxWorks specific */
/* We define this because we want the standard streams to use streambufs 
 * (that write  to file descriptors which are valid across all threads) rather
 * than stdiobufs */
#define _STDIO_USES_IOSTREAM
/* End VxWorks specific */

#ifdef _STDIO_USES_IOSTREAM
_IO_FILE *_IO_list_all = &_IO_stderr_.file;
#else /* !_STDIO_USES_IOSTREAM */
#include "stdiostream.h"

struct _IO_fake_stdiobuf {
  struct {
    _IO_FILE file;
    const void *vtable;
  } s;
  FILE *stdio_file;
};

/* Define stdiobuf_vtable as a name for the virtual function table
   of the stdiobuf class. */
#ifndef stdiobuf_vtable
#ifdef __GNUC__
extern struct _IO_jump_t stdiobuf_vtable
  asm (_G_VTABLE_LABEL_PREFIX
#if _G_VTABLE_LABEL_HAS_LENGTH
       "8"
#endif
       "stdiobuf");
#else /* !__GNUC__ */
#if _G_VTABLE_LABEL_HAS_LENGTH
#define stdiobuf_vtable _G_VTABLE_LABEL_PREFIX_ID##8stdiobuf
#else
#define stdiobuf_vtable _G_VTABLE_LABEL_PREFIX_ID##stdiobuf
#endif
extern struct _IO_jump_t stdiobuf_vtable;
#endif /* !__GNUC__ */
#endif /* !stdiobuf_vtable */

#ifdef _IO_MTSAFE_IO
#define DEF_STDIOFILE(NAME, FD, FILE, FLAGS, CHAIN) \
  struct _IO_fake_stdiobuf NAME = \
      {{{ _IO_MAGIC+_IO_LINKED+_IO_IS_FILEBUF+_IO_UNBUFFERED+FLAGS, \
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, CHAIN, FD, \
	 0, 0, 0, 0, { 0 }, &_IO_stdfile_##FD##_lock},\
         &stdiobuf_vtable}, FILE}
#else
#define DEF_STDIOFILE(NAME, FD, FILE, FLAGS, CHAIN) \
  struct _IO_fake_stdiobuf NAME = \
      {{{ _IO_MAGIC+_IO_LINKED+_IO_IS_FILEBUF+_IO_UNBUFFERED+FLAGS, \
	    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, CHAIN, FD}, \
         &stdiobuf_vtable}, FILE}
#endif

DEF_STDIOFILE(_IO_stdin_buf, 0, stdin, _IO_NO_WRITES, &_IO_stderr_.file);
DEF_STDIOFILE(_IO_stdout_buf, 1, stdout, _IO_NO_READS, &_IO_stdin_buf.s.file);
DEF_STDIOFILE(_IO_stderr_buf, 2, stderr, _IO_NO_READS, &_IO_stdout_buf.s.file);

_IO_FILE *_IO_list_all = &_IO_stderr_buf.s.file;
#endif  /* !_STDIO_USES_IOSTREAM */