1/* This is part of libio/iostream, providing -*- C++ -*- input/output.
2Copyright (C) 1993 Free Software Foundation
3
4This file is part of the GNU IO Library.  This library is free
5software; you can redistribute it and/or modify it under the
6terms of the GNU General Public License as published by the
7Free Software Foundation; either version 2, or (at your option)
8any later version.
9
10This library is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with this library; see the file COPYING.  If not, write to the Free
17Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
18
19As a special exception, if you link this library with files
20compiled with a GNU compiler to produce an executable, this does not cause
21the resulting executable to be covered by the GNU General Public License.
22This exception does not however invalidate any other reasons why
23the executable file might be covered by the GNU General Public License. */
24
25/* Written by Per Bothner (bothner@cygnus.com). */
26
27#include "libioP.h"
28#include "streambuf.h"
29#include <stdio.h>
30
31// The ANSI draft requires that operations on cin/cout/cerr can be
32// mixed with operations on stdin/stdout/stderr on a character by
33// character basis.  This normally requires that the streambuf's
34// used by cin/cout/cerr be stdiostreams.  However, if the stdio
35// implementation is the one that is built using this library,
36// then we don't need to, since in that case stdin/stdout/stderr
37// are identical to _IO_stdin/_IO_stdout/_IO_stderr.
38
39#include <libio.h>
40
41#ifdef _STDIO_USES_IOSTREAM
42#define CIN_SBUF _IO_stdin_
43#define COUT_SBUF _IO_stdout_
44#define CERR_SBUF _IO_stderr_
45static int use_stdiobuf = 0;
46#else
47#define CIN_SBUF _IO_stdin_buf
48#define COUT_SBUF _IO_stdout_buf
49#define CERR_SBUF _IO_stderr_buf
50static int use_stdiobuf = 1;
51#endif
52
53#define cin CIN
54#define cout COUT
55#define cerr CERR
56#define clog CLOG
57#include "iostream.h"
58#undef cin
59#undef cout
60#undef cerr
61#undef clog
62
63#ifdef __GNUG__
64#define PAD 0 /* g++ allows 0-length arrays. */
65#else
66#define PAD 1
67#endif
68struct _fake_istream {
69    struct myfields {
70#ifdef __GNUC__
71	_ios_fields *vb; /* pointer to virtual base class ios */
72	_IO_ssize_t _gcount;
73#else
74	/* This is supposedly correct for cfront. */
75	_IO_ssize_t _gcount;
76	void *vptr;
77	_ios_fields *vb; /* pointer to virtual base class ios */
78#endif
79    } mine;
80    _ios_fields base;
81    char filler[sizeof(struct istream)-sizeof(struct _ios_fields)+PAD];
82};
83struct _fake_ostream {
84    struct myfields {
85#ifndef __GNUC__
86	void *vptr;
87#endif
88	_ios_fields *vb; /* pointer to virtual base class ios */
89    } mine;
90    _ios_fields base;
91    char filler[sizeof(struct ostream)-sizeof(struct _ios_fields)+PAD];
92};
93
94
95#ifdef _IO_NEW_STREAMS
96#define STD_STR(SBUF, TIE, EXTRA_FLAGS) \
97 (streambuf*)&SBUF, TIE, 0, ios::skipws|ios::dec|EXTRA_FLAGS, ' ',0,0,6
98#else
99#define STD_STR(SBUF, TIE, EXTRA_FLAGS) \
100 (streambuf*)&SBUF, TIE, 0, ios::dont_close|ios::dec|ios::skipws|EXTRA_FLAGS, ' ',0,0,6
101#endif
102
103#ifdef __GNUC__
104#define OSTREAM_DEF(NAME, SBUF, TIE, EXTRA_FLAGS, ASM) \
105  _fake_ostream NAME ASM = { {&NAME.base}, {STD_STR(SBUF, TIE, EXTRA_FLAGS) }};
106#define ISTREAM_DEF(NAME, SBUF, TIE, EXTRA_FLAGS) \
107  _fake_istream NAME = { {&NAME.base}, {STD_STR(SBUF, TIE, EXTRA_FLAGS) }};
108#else
109#define OSTREAM_DEF(NAME, SBUF, TIE, EXTRA_FLAGS) \
110  _fake_ostream NAME = { {0, &NAME.base}, {STD_STR(SBUF, TIE, EXTRA_FLAGS) }};
111#define ISTREAM_DEF(NAME, SBUF, TIE, EXTRA_FLAGS) \
112  _fake_istream NAME = {{0, 0, &NAME.base}, {STD_STR(SBUF, TIE, EXTRA_FLAGS)}};
113#endif
114
115OSTREAM_DEF(cout, COUT_SBUF, NULL, 0, )
116OSTREAM_DEF(cerr, CERR_SBUF,(ostream*)&cout, ios::unitbuf, )
117ISTREAM_DEF(cin, CIN_SBUF,  (ostream*)&cout, 0)
118
119/* Only for (partial) compatibility with AT&T's library. */
120#if _G_CLOG_CONFLICT
121OSTREAM_DEF(clog, CERR_SBUF, (ostream*)&cout, 0, __asm__ ("__IO_clog"))
122#else
123OSTREAM_DEF(clog, CERR_SBUF, (ostream*)&cout, 0, )
124#endif
125
126// Switches between using _IO_std{in,out,err} and __std{in,out,err}_buf
127// for standard streams.  This does not normally need to be called
128// explicitly, but is provided for AT&T compatibility.
129
130int ios::sync_with_stdio(int new_state)
131{
132#ifdef _STDIO_USES_IOSTREAM
133    // It is always synced.
134    return 0;
135#else
136    if (new_state == use_stdiobuf) // The usual case now.
137	return use_stdiobuf;
138    if (new_state) {
139	cin.base._strbuf = (streambuf*)&_IO_stdin_buf;
140	cout.base._strbuf = (streambuf*)&_IO_stdout_buf;
141	cerr.base._strbuf = (streambuf*)&_IO_stderr_buf;
142	clog.base._strbuf = (streambuf*)&_IO_stderr_buf;
143    } else {
144	cin.base._strbuf = (streambuf*)_IO_stdin;
145	cout.base._strbuf = (streambuf*)_IO_stdout;
146	cerr.base._strbuf = (streambuf*)_IO_stderr;
147	clog.base._strbuf = (streambuf*)_IO_stderr;
148    }
149    int old_state = use_stdiobuf;
150    use_stdiobuf = new_state;
151    return old_state;
152#endif
153}
154