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gcc/libstdc++-v3/include/bits/fstream.tcc
Benjamin Kosnik 9fbcb61abb [multiple changes] 
2002-01-08  Benjamin Kosnik  <bkoz@redhat.com>

        libstdc++/2913
        libstdc++/4879
	* include/bits/fstream.tcc (filebuf::_M_really_overflow): Test
	return value of _M_file->sync().
	(filebuf::showmanyc): Check for is_open.
	* include/std/fstream (filebuf::sync): Tweak.
	* testsuite/27_io/filebuf.cc: Tweak.

2002-01-08  John Fardo  <jfardo@laurelnetworks.com>
	    Brad Garcia  <garsh@attbi.com>

	* testsuite/27_io/filebuf_members.cc: Add test.

From-SVN: r48654
2002-01-08 19:57:01 +00:00

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// File based streams -*- C++ -*-
// Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ 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, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself 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.
//
// ISO C++ 14882: 27.8 File-based streams
//
#ifndef _CPP_BITS_FSTREAM_TCC
#define _CPP_BITS_FSTREAM_TCC 1
namespace std
{
template<typename _CharT, typename _Traits>
void
basic_filebuf<_CharT, _Traits>::
_M_allocate_file()
{
if (!_M_file)
{
_M_buf_unified = true; // Tie input to output for basic_filebuf.
try
{ _M_file = new __file_type(&_M_lock); }
catch(...)
{
delete _M_file;
__throw_exception_again;
}
}
}
template<typename _CharT, typename _Traits>
void
basic_filebuf<_CharT, _Traits>::
_M_allocate_internal_buffer()
{
if (!_M_buf && _M_buf_size_opt)
{
_M_buf_size = _M_buf_size_opt;
// Allocate internal buffer.
try { _M_buf = new char_type[_M_buf_size]; }
catch(...)
{
delete [] _M_buf;
__throw_exception_again;
}
_M_buf_allocated = true;
}
}
// Both close and setbuf need to deallocate internal buffers, if it exists.
template<typename _CharT, typename _Traits>
void
basic_filebuf<_CharT, _Traits>::
_M_destroy_internal_buffer()
{
if (_M_buf_allocated)
{
delete [] _M_buf;
_M_buf = NULL;
_M_buf_allocated = false;
this->setg(NULL, NULL, NULL);
this->setp(NULL, NULL);
}
}
template<typename _CharT, typename _Traits>
void
basic_filebuf<_CharT, _Traits>::
_M_allocate_pback_buffer()
{
if (!_M_pback && _M_pback_size)
{
// Allocate pback buffer.
try
{ _M_pback = new char_type[_M_pback_size]; }
catch(...)
{
delete [] _M_pback;
__throw_exception_again;
}
}
}
template<typename _CharT, typename _Traits>
basic_filebuf<_CharT, _Traits>::
basic_filebuf()
: __streambuf_type(), _M_file(NULL), _M_state_cur(__state_type()),
_M_state_beg(__state_type()), _M_buf_allocated(false),
_M_last_overflowed(false)
{ }
template<typename _CharT, typename _Traits>
basic_filebuf<_CharT, _Traits>::
basic_filebuf(__c_file_type* __f, ios_base::openmode __mode, int_type __s)
: __streambuf_type(), _M_file(NULL), _M_state_cur(__state_type()),
_M_state_beg(__state_type()), _M_buf_allocated(false),
_M_last_overflowed(false)
{
_M_allocate_file();
_M_file->sys_open(__f, __mode);
if (this->is_open())
{
_M_mode = __mode;
if (__s)
{
_M_buf_size_opt = __s;
_M_allocate_internal_buffer();
_M_set_indeterminate();
}
_M_allocate_pback_buffer();
}
}
template<typename _CharT, typename _Traits>
int
basic_filebuf<_CharT, _Traits>::
fd()
{
return _M_file->fd();
}
template<typename _CharT, typename _Traits>
typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
basic_filebuf<_CharT, _Traits>::
open(const char* __s, ios_base::openmode __mode)
{
__filebuf_type *__ret = NULL;
if (!this->is_open())
{
_M_allocate_file();
_M_file->open(__s, __mode);
if (this->is_open())
{
_M_allocate_internal_buffer();
_M_allocate_pback_buffer();
_M_mode = __mode;
// For time being, set both (in/out) sets of pointers.
_M_set_indeterminate();
if (__mode & ios_base::ate
&& this->seekoff(0, ios_base::end, __mode) < 0)
this->close();
__ret = this;
}
}
return __ret;
}
template<typename _CharT, typename _Traits>
typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
basic_filebuf<_CharT, _Traits>::
close()
{
__filebuf_type *__ret = NULL;
if (this->is_open())
{
bool __testput = _M_out_cur && _M_out_beg < _M_out_end;
if (__testput
&& _M_really_overflow(traits_type::eof()) != traits_type::eof())
{
// NB: Do this here so that re-opened filebufs will be cool...
_M_mode = ios_base::openmode(0);
_M_destroy_internal_buffer();
_M_pback_destroy();
if (_M_pback)
{
delete [] _M_pback;
_M_pback = NULL;
}
#if 0
// XXX not done
if (_M_last_overflowed)
{
_M_output_unshift();
_M_really_overflow(traits_type::eof());
}
#endif
__ret = this;
}
}
// Can actually allocate this file as part of an open and never
// have it be opened.....
if (_M_file)
{
delete _M_file;
_M_file = NULL;
}
_M_last_overflowed = false;
return __ret;
}
template<typename _CharT, typename _Traits>
streamsize
basic_filebuf<_CharT, _Traits>::
showmanyc()
{
streamsize __ret = -1;
bool __testin = _M_mode & ios_base::in;
if (__testin && this->is_open())
{
if (_M_in_cur < _M_in_end)
__ret = _M_in_end - _M_in_cur;
else
__ret = 0;
}
_M_last_overflowed = false;
return __ret;
}
template<typename _CharT, typename _Traits>
typename basic_filebuf<_CharT, _Traits>::int_type
basic_filebuf<_CharT, _Traits>::
underflow()
{
int_type __ret = traits_type::eof();
bool __testin = _M_mode & ios_base::in;
bool __testout = _M_mode & ios_base::out;
// XXX Should re-enable codecvt bits disabled after 2.90.8.
if (__testin)
{
// Check for pback madness, and if so swich back to the
// normal buffers and jet outta here before expensive
// fileops happen...
if (_M_pback_init)
{
_M_pback_destroy();
if (_M_in_cur < _M_in_end)
return traits_type::to_int_type(*_M_in_cur);
}
bool __testget = _M_in_cur && _M_in_beg < _M_in_cur;
bool __testinit = _M_is_indeterminate();
// Sync internal and external buffers.
// NB: __testget -> __testput as _M_buf_unified here.
if (__testget)
{
if (__testout)
_M_really_overflow();
#if _GLIBCPP_AVOID_FSEEK
else if ((_M_in_cur - _M_in_beg) == 1)
_M_file->sys_getc();
#endif
else
_M_file->seekoff(_M_in_cur - _M_in_beg,
ios_base::cur, ios_base::in);
}
if (__testinit || __testget)
{
// Assume buffered case, need to refill internal buffers.
streamsize __size = _M_file->xsgetn(_M_in_beg, _M_buf_size);
if (0 < __size)
{
_M_set_determinate(__size);
if (__testout)
_M_out_cur = _M_in_cur;
__ret = traits_type::to_int_type(*_M_in_cur);
#if _GLIBCPP_AVOID_FSEEK
if (__size == 1)
_M_file->sys_ungetc(*_M_in_cur);
else
{
#endif
streamoff __p = _M_file->seekoff(0 - __size, ios_base::cur,
ios_base::in);
if (__p == -1)
{
// XXX Something is wrong, do error checking.
}
#if _GLIBCPP_AVOID_FSEEK
}
#endif
}
}
}
_M_last_overflowed = false;
return __ret;
}
template<typename _CharT, typename _Traits>
typename basic_filebuf<_CharT, _Traits>::int_type
basic_filebuf<_CharT, _Traits>::
pbackfail(int_type __i)
{
int_type __ret = traits_type::eof();
bool __testin = _M_mode & ios_base::in;
if (__testin)
{
bool __testpb = _M_in_beg < _M_in_cur;
char_type __c = traits_type::to_char_type(__i);
bool __testeof = traits_type::eq_int_type(__i, __ret);
if (__testpb)
{
bool __testout = _M_mode & ios_base::out;
bool __testeq = traits_type::eq(__c, this->gptr()[-1]);
// Try to put back __c into input sequence in one of three ways.
// Order these tests done in is unspecified by the standard.
if (!__testeof && __testeq)
{
--_M_in_cur;
if (__testout)
--_M_out_cur;
__ret = __i;
}
else if (__testeof)
{
--_M_in_cur;
if (__testout)
--_M_out_cur;
__ret = traits_type::not_eof(__i);
}
else if (!__testeof)
{
--_M_in_cur;
if (__testout)
--_M_out_cur;
_M_pback_create();
*_M_in_cur = __c;
__ret = __i;
}
}
else
{
// At the beginning of the buffer, need to make a
// putback position available.
this->seekoff(-1, ios_base::cur);
this->underflow();
if (!__testeof)
{
if (!traits_type::eq(__c, *_M_in_cur))
{
_M_pback_create();
*_M_in_cur = __c;
}
__ret = __i;
}
else
__ret = traits_type::not_eof(__i);
}
}
_M_last_overflowed = false;
return __ret;
}
template<typename _CharT, typename _Traits>
typename basic_filebuf<_CharT, _Traits>::int_type
basic_filebuf<_CharT, _Traits>::
overflow(int_type __c)
{
int_type __ret = traits_type::eof();
bool __testput = _M_out_cur && _M_out_cur < _M_buf + _M_buf_size;
bool __testout = _M_mode & ios_base::out;
if (__testout)
{
if (__testput)
{
*_M_out_cur = traits_type::to_char_type(__c);
_M_out_cur_move(1);
__ret = traits_type::not_eof(__c);
}
else
__ret = this->_M_really_overflow(__c);
}
_M_last_overflowed = false; // Set in _M_really_overflow, below.
return __ret;
}
template<typename _CharT, typename _Traits>
typename basic_filebuf<_CharT, _Traits>::int_type
basic_filebuf<_CharT, _Traits>::
_M_really_overflow(int_type __c)
{
int_type __ret = traits_type::eof();
bool __testput = _M_out_cur && _M_out_beg < _M_out_end;
bool __testunbuffered = _M_file && !_M_buf_size;
if (__testput || __testunbuffered)
{
#if 1
int __plen = _M_out_end - _M_out_beg;
streamsize __len = 0;
if (__plen)
__len = _M_file->xsputn(_M_out_beg, __plen);
if (__c != traits_type::eof())
{
char_type __pending = traits_type::to_char_type(__c);
__len += _M_file->xsputn(&__pending, 1);
++__plen;
}
// NB: Need this so that external byte sequence reflects
// internal buffer.
if (__len == __plen)
_M_set_indeterminate();
if (!_M_file->sync())
__ret = traits_type::not_eof(__c);
#else
// Part one: Allocate temporary conversion buffer on
// stack. Convert internal buffer plus __c (ie,
// "pending sequence") to temporary conversion buffer.
int __plen = _M_out_end - _M_out_beg;
char_type* __pbuf = static_cast<char_type*>(__builtin_alloca(sizeof(char_type) * __plen + 1));
traits_type::copy(__pbuf, this->pbase(), __plen);
if (!__testeof)
{
__pbuf[__plen] = traits_type::to_char_type(__c);
++__plen;
}
char_type* __pend;
char* __conv_buf = static_cast<char*>(__builtin_alloca(__plen));
char* __conv_end;
_M_state_beg = _M_state_cur;
__res_type __r = _M_fcvt->out(_M_state_cur,
__pbuf, __pbuf + __plen,
const_cast<const char_type*&>(__pend),
__conv_buf, __conv_buf + __plen,
__conv_end);
// Part two: (Re)spill converted "pending sequence"
// contents (now in temporary conversion buffer) to
// external buffer (_M_file->_IO_*) using
// _M_file->sys_write(), and do error (minimal) checking.
if (__r != codecvt_base::error)
{
streamsize __len = _M_file->xsputn(__conv_buf, __plen);
// NB: Need this so that external byte sequence reflects
// internal buffer.
_M_file->sync(); // XXX error check
if (__len == __plen)
{
_M_set_indeterminate();
__ret = traits_type::not_eof(__c);
}
}
#endif
}
_M_last_overflowed = true;
return __ret;
}
template<typename _CharT, typename _Traits>
typename basic_filebuf<_CharT, _Traits>::__streambuf_type*
basic_filebuf<_CharT, _Traits>::
setbuf(char_type* __s, streamsize __n)
{
if (!this->is_open() && __s == 0 && __n == 0)
_M_buf_size_opt = 0;
else if (__s && __n)
{
// This is implementation-defined behavior, and assumes
// that an external char_type array of length (__s + __n)
// exists and has been pre-allocated. If this is not the
// case, things will quickly blow up.
// Step 1: Destroy the current internal array.
_M_destroy_internal_buffer();
// Step 2: Use the external array.
_M_buf = __s;
_M_buf_size_opt = _M_buf_size = __n;
_M_set_indeterminate();
// Step 3: Make sure a pback buffer is allocated.
_M_allocate_pback_buffer();
}
_M_last_overflowed = false;
return this;
}
template<typename _CharT, typename _Traits>
typename basic_filebuf<_CharT, _Traits>::pos_type
basic_filebuf<_CharT, _Traits>::
seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
{
pos_type __ret = pos_type(off_type(-1));
bool __testopen = this->is_open();
bool __testin = __mode & ios_base::in && _M_mode & ios_base::in;
bool __testout = __mode & ios_base::out && _M_mode & ios_base::out;
// Should probably do has_facet checks here.
int __width = use_facet<__codecvt_type>(_M_buf_locale).encoding();
if (__width < 0)
__width = 0;
bool __testfail = __off != 0 && __width <= 0;
if (__testopen && !__testfail && (__testin || __testout))
{
// Ditch any pback buffers to avoid confusion.
_M_pback_destroy();
if (__way != ios_base::cur || __off != 0)
{
off_type __computed_off = __width * __off;
bool __testget = _M_in_cur && _M_in_beg < _M_in_end;
bool __testput = _M_out_cur && _M_out_beg < _M_out_end;
// Sync the internal and external streams.
// out
if (__testput || _M_last_overflowed)
{
// Part one: update the output sequence.
this->sync();
// Part two: output unshift sequence.
_M_output_unshift();
}
//in
// NB: underflow() rewinds the external buffer.
else if (__testget && __way == ios_base::cur)
__computed_off += _M_in_cur - _M_in_beg;
__ret = _M_file->seekoff(__computed_off, __way, __mode);
_M_set_indeterminate();
}
// NB: Need to do this in case _M_file in indeterminate
// state, ie _M_file->_offset == -1
else
{
__ret = _M_file->seekoff(__off, ios_base::cur, __mode);
__ret += max(_M_out_cur, _M_in_cur) - _M_buf;
}
}
_M_last_overflowed = false;
return __ret;
}
template<typename _CharT, typename _Traits>
typename basic_filebuf<_CharT, _Traits>::pos_type
basic_filebuf<_CharT, _Traits>::
seekpos(pos_type __pos, ios_base::openmode __mode)
{
pos_type __ret;
off_type __off = __pos;
__ret = this->seekoff(__off, ios_base::beg, __mode);
_M_last_overflowed = false;
return __ret;
}
template<typename _CharT, typename _Traits>
void
basic_filebuf<_CharT, _Traits>::
_M_output_unshift()
{ }
template<typename _CharT, typename _Traits>
void
basic_filebuf<_CharT, _Traits>::
imbue(const locale& __loc)
{
bool __testbeg = gptr() == eback() && pptr() == pbase();
if (__testbeg && _M_buf_locale != __loc)
{
_M_buf_locale = __loc;
_M_buf_locale_init = true;
}
// NB this may require the reconversion of previously
// converted chars. This in turn may cause the reconstruction
// of the original file. YIKES!!
// XXX The part in the above comment is not done.
_M_last_overflowed = false;
}
} // namespace std
#endif // _CPP_BITS_FSTREAM_TCC
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