/* This is part of libio/iostream, providing -*- C++ -*- input/output.
Copyright (C) 1993 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, 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. */

/* Written by Per Bothner (bothner@cygnus.com). */

#include "libioP.h"
#include "streambuf.h"

// The ANSI draft requires that operations on cin/cout/cerr can be
// mixed with operations on stdin/stdout/stderr on a character by
// character basis.  This normally requires that the streambuf's
// used by cin/cout/cerr be stdiostreams.  However, if the stdio
// implementation is the one that is built using this library,
// then we don't need to, since in that case stdin/stdout/stderr
// are identical to &__std_filebuf_0/&__std_filebuf_1/&__std_filebuf_2.

#if 1 //def _STDIO_USES_IOSTREAM
#define USE_FILEBUF
#endif

#ifdef NAMES_HAVE_UNDERSCORE
#define UNDERSCORE "_"
#else
#define UNDERSCORE ""
#endif

#ifdef USE_FILEBUF
#if 1
#include "libio.h"
#define CIN_SBUF _IO_stdin_
#define COUT_SBUF _IO_stdout_
#define CERR_SBUF _IO_stderr_
#else
#define CIN_SBUF __std_filebuf_0
#define COUT_SBUF __std_filebuf_1
#define CERR_SBUF __std_filebuf_2
#endif
static int use_stdiobuf = 0;
#else
#define CIN_SBUF __stdin_stdiobuf
#define COUT_SBUF __stdout_stdiobuf
#define CERR_SBUF __stderr_stdiobuf
static int use_stdiobuf = 1;
#endif

#if 1
struct _fake_filebuf;
extern _fake_filebuf __std_filebuf_0, __std_filebuf_1, __std_filebuf_2;
#endif
struct _fake_stdiobuf;
extern _fake_stdiobuf __stdin_stdiobuf, __stdout_stdiobuf, __stderr_stdiobuf;

#define cin CIN
#define cout COUT
#define cerr CERR
#define clog CLOG
#include "iostream.h"
#undef cin
#undef cout
#undef cerr
#undef clog

#ifdef __GNUG__
#define PAD 0 /* g++ allows 0-length arrays. */
#else
#define PAD 1
#endif
struct _fake_istream {
    struct myfields {
#ifdef __GNUC__
	_ios_fields *vb; /* pointer to virtual base class ios */
	_IO_ssize_t _gcount;
#else
	/* This is supposedly correct for cfront. */
	_IO_ssize_t _gcount;
	void *vptr;
	_ios_fields *vb; /* pointer to virtual base class ios */
#endif
    } mine;
    _ios_fields base;
    char filler[sizeof(struct istream)-sizeof(struct _ios_fields)+PAD];
};
struct _fake_ostream {
    struct myfields {
#ifndef __GNUC__
	void *vptr;
#endif
	_ios_fields *vb; /* pointer to virtual base class ios */
    } mine;
    _ios_fields base;
    char filler[sizeof(struct ostream)-sizeof(struct _ios_fields)+PAD];
};

#define STD_STR(SBUF, TIE, EXTRA_FLAGS) \
 (streambuf*)&SBUF, TIE, 0, ios::dont_close|ios::skipws|EXTRA_FLAGS, ' ',0,0,6

#ifdef __GNUC__
#define OSTREAM_DEF(TYPE, NAME, SBUF, TIE, EXTRA_FLAGS) \
  TYPE NAME = { {&NAME.base}, {STD_STR(SBUF, TIE, EXTRA_FLAGS) }};
#define ISTREAM_DEF(TYPE, NAME, SBUF, TIE, EXTRA_FLAGS) \
  TYPE NAME = { {&NAME.base}, {STD_STR(SBUF, TIE, EXTRA_FLAGS) }};
#else
#define OSTREAM_DEF(TYPE, NAME, SBUF, TIE, EXTRA_FLAGS) \
  TYPE NAME = { {0, &NAME.base}, {STD_STR(SBUF, TIE, EXTRA_FLAGS) }};
#define ISTREAM_DEF(TYPE, NAME, SBUF, TIE, EXTRA_FLAGS) \
  TYPE NAME = { {0, 0, &NAME.base}, {STD_STR(SBUF, TIE, EXTRA_FLAGS) }};
#endif

OSTREAM_DEF(_fake_ostream, cout, COUT_SBUF, NULL, 0)
OSTREAM_DEF(_fake_ostream, cerr, CERR_SBUF, (ostream*)&cout, ios::unitbuf)
ISTREAM_DEF(_fake_istream, cin, CIN_SBUF,  (ostream*)&cout, 0)

/* Only for (partial) compatibility with AT&T's library. */
OSTREAM_DEF(_fake_ostream, clog, CERR_SBUF, (ostream*)&cout, 0)

// Switches between using __std_filebuf_{0,1,2} and
// __std{in,out,err}_stdiobuf for standard streams.  This is
// normally not needed, but is provided for AT&T compatibility.

int ios::sync_with_stdio(int new_state)
{
#ifdef TODO
#ifdef _STDIO_USES_IOSTREAM
    // It is always synced.
    return 0;
#else
    if (new_state == use_stdiobuf) // The usual case now.
	return use_stdiobuf;
    if (new_state) {
	cout.base._strbuf = (streambuf*)&__stdout_stdiobuf;
	cin.base._strbuf = (streambuf*)&__stdin_stdiobuf;
	cerr.base._strbuf = (streambuf*)&__stderr_stdiobuf;
	clog.base._strbuf = (streambuf*)&__stderr_stdiobuf;
    } else {
	cout.base._strbuf = (streambuf*)&__std_filebuf_1;
	cin.base._strbuf = (streambuf*)&__std_filebuf_0;
	cerr.base._strbuf = (streambuf*)&__std_filebuf_2;
	clog.base._strbuf = (streambuf*)&__std_filebuf_2;
    }
    int old_state = use_stdiobuf;
    use_stdiobuf = new_state;
    return old_state;
#endif
#endif
    return 0;
}
