986 lines
28 KiB
C++
986 lines
28 KiB
C++
// File based streams -*- C++ -*-
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// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
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// 2007, 2008, 2009, 2010, 2011
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// Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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/** @file bits/fstream.tcc
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* This is an internal header file, included by other library headers.
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* Do not attempt to use it directly. @headername{fstream}
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*/
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//
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// ISO C++ 14882: 27.8 File-based streams
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//
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#ifndef _FSTREAM_TCC
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#define _FSTREAM_TCC 1
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#pragma GCC system_header
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#include <bits/cxxabi_forced.h>
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namespace std _GLIBCXX_VISIBILITY(default)
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{
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_GLIBCXX_BEGIN_NAMESPACE_VERSION
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template<typename _CharT, typename _Traits>
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void
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basic_filebuf<_CharT, _Traits>::
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_M_allocate_internal_buffer()
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{
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// Allocate internal buffer only if one doesn't already exist
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// (either allocated or provided by the user via setbuf).
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if (!_M_buf_allocated && !_M_buf)
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{
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_M_buf = new char_type[_M_buf_size];
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_M_buf_allocated = true;
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}
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}
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template<typename _CharT, typename _Traits>
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void
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basic_filebuf<_CharT, _Traits>::
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_M_destroy_internal_buffer() throw()
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{
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if (_M_buf_allocated)
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{
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delete [] _M_buf;
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_M_buf = 0;
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_M_buf_allocated = false;
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}
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delete [] _M_ext_buf;
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_M_ext_buf = 0;
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_M_ext_buf_size = 0;
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_M_ext_next = 0;
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_M_ext_end = 0;
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}
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template<typename _CharT, typename _Traits>
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basic_filebuf<_CharT, _Traits>::
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basic_filebuf() : __streambuf_type(), _M_lock(), _M_file(&_M_lock),
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_M_mode(ios_base::openmode(0)), _M_state_beg(), _M_state_cur(),
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_M_state_last(), _M_buf(0), _M_buf_size(BUFSIZ),
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_M_buf_allocated(false), _M_reading(false), _M_writing(false), _M_pback(),
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_M_pback_cur_save(0), _M_pback_end_save(0), _M_pback_init(false),
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_M_codecvt(0), _M_ext_buf(0), _M_ext_buf_size(0), _M_ext_next(0),
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_M_ext_end(0)
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{
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if (has_facet<__codecvt_type>(this->_M_buf_locale))
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_M_codecvt = &use_facet<__codecvt_type>(this->_M_buf_locale);
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}
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template<typename _CharT, typename _Traits>
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typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
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basic_filebuf<_CharT, _Traits>::
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open(const char* __s, ios_base::openmode __mode)
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{
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__filebuf_type *__ret = 0;
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if (!this->is_open())
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{
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_M_file.open(__s, __mode);
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if (this->is_open())
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{
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_M_allocate_internal_buffer();
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_M_mode = __mode;
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// Setup initial buffer to 'uncommitted' mode.
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_M_reading = false;
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_M_writing = false;
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_M_set_buffer(-1);
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// Reset to initial state.
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_M_state_last = _M_state_cur = _M_state_beg;
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// 27.8.1.3,4
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if ((__mode & ios_base::ate)
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&& this->seekoff(0, ios_base::end, __mode)
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== pos_type(off_type(-1)))
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this->close();
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else
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__ret = this;
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}
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}
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return __ret;
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}
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template<typename _CharT, typename _Traits>
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typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
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basic_filebuf<_CharT, _Traits>::
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close()
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{
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if (!this->is_open())
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return 0;
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bool __testfail = false;
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{
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// NB: Do this here so that re-opened filebufs will be cool...
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struct __close_sentry
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{
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basic_filebuf *__fb;
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__close_sentry (basic_filebuf *__fbi): __fb(__fbi) { }
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~__close_sentry ()
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{
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__fb->_M_mode = ios_base::openmode(0);
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__fb->_M_pback_init = false;
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__fb->_M_destroy_internal_buffer();
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__fb->_M_reading = false;
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__fb->_M_writing = false;
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__fb->_M_set_buffer(-1);
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__fb->_M_state_last = __fb->_M_state_cur = __fb->_M_state_beg;
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}
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} __cs (this);
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__try
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{
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if (!_M_terminate_output())
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__testfail = true;
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}
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__catch(__cxxabiv1::__forced_unwind&)
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{
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_M_file.close();
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__throw_exception_again;
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}
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__catch(...)
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{ __testfail = true; }
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}
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if (!_M_file.close())
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__testfail = true;
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if (__testfail)
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return 0;
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else
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return this;
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}
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template<typename _CharT, typename _Traits>
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streamsize
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basic_filebuf<_CharT, _Traits>::
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showmanyc()
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{
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streamsize __ret = -1;
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const bool __testin = _M_mode & ios_base::in;
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if (__testin && this->is_open())
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{
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// For a stateful encoding (-1) the pending sequence might be just
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// shift and unshift prefixes with no actual character.
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__ret = this->egptr() - this->gptr();
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#if _GLIBCXX_HAVE_DOS_BASED_FILESYSTEM
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// About this workaround, see libstdc++/20806.
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const bool __testbinary = _M_mode & ios_base::binary;
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if (__check_facet(_M_codecvt).encoding() >= 0
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&& __testbinary)
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#else
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if (__check_facet(_M_codecvt).encoding() >= 0)
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#endif
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__ret += _M_file.showmanyc() / _M_codecvt->max_length();
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}
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return __ret;
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}
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template<typename _CharT, typename _Traits>
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typename basic_filebuf<_CharT, _Traits>::int_type
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basic_filebuf<_CharT, _Traits>::
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underflow()
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{
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int_type __ret = traits_type::eof();
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const bool __testin = _M_mode & ios_base::in;
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if (__testin)
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{
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if (_M_writing)
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{
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if (overflow() == traits_type::eof())
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return __ret;
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_M_set_buffer(-1);
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_M_writing = false;
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}
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// Check for pback madness, and if so switch back to the
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// normal buffers and jet outta here before expensive
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// fileops happen...
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_M_destroy_pback();
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if (this->gptr() < this->egptr())
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return traits_type::to_int_type(*this->gptr());
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// Get and convert input sequence.
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const size_t __buflen = _M_buf_size > 1 ? _M_buf_size - 1 : 1;
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// Will be set to true if ::read() returns 0 indicating EOF.
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bool __got_eof = false;
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// Number of internal characters produced.
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streamsize __ilen = 0;
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codecvt_base::result __r = codecvt_base::ok;
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if (__check_facet(_M_codecvt).always_noconv())
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{
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__ilen = _M_file.xsgetn(reinterpret_cast<char*>(this->eback()),
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__buflen);
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if (__ilen == 0)
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__got_eof = true;
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}
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else
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{
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// Worst-case number of external bytes.
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// XXX Not done encoding() == -1.
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const int __enc = _M_codecvt->encoding();
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streamsize __blen; // Minimum buffer size.
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streamsize __rlen; // Number of chars to read.
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if (__enc > 0)
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__blen = __rlen = __buflen * __enc;
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else
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{
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__blen = __buflen + _M_codecvt->max_length() - 1;
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__rlen = __buflen;
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}
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const streamsize __remainder = _M_ext_end - _M_ext_next;
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__rlen = __rlen > __remainder ? __rlen - __remainder : 0;
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// An imbue in 'read' mode implies first converting the external
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// chars already present.
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if (_M_reading && this->egptr() == this->eback() && __remainder)
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__rlen = 0;
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// Allocate buffer if necessary and move unconverted
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// bytes to front.
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if (_M_ext_buf_size < __blen)
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{
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char* __buf = new char[__blen];
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if (__remainder)
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__builtin_memcpy(__buf, _M_ext_next, __remainder);
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delete [] _M_ext_buf;
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_M_ext_buf = __buf;
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_M_ext_buf_size = __blen;
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}
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else if (__remainder)
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__builtin_memmove(_M_ext_buf, _M_ext_next, __remainder);
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_M_ext_next = _M_ext_buf;
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_M_ext_end = _M_ext_buf + __remainder;
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_M_state_last = _M_state_cur;
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do
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{
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if (__rlen > 0)
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{
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// Sanity check!
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// This may fail if the return value of
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// codecvt::max_length() is bogus.
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if (_M_ext_end - _M_ext_buf + __rlen > _M_ext_buf_size)
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{
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__throw_ios_failure(__N("basic_filebuf::underflow "
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"codecvt::max_length() "
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"is not valid"));
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}
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streamsize __elen = _M_file.xsgetn(_M_ext_end, __rlen);
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if (__elen == 0)
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__got_eof = true;
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else if (__elen == -1)
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break;
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_M_ext_end += __elen;
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}
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char_type* __iend = this->eback();
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if (_M_ext_next < _M_ext_end)
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__r = _M_codecvt->in(_M_state_cur, _M_ext_next,
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_M_ext_end, _M_ext_next,
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this->eback(),
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this->eback() + __buflen, __iend);
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if (__r == codecvt_base::noconv)
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{
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size_t __avail = _M_ext_end - _M_ext_buf;
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__ilen = std::min(__avail, __buflen);
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traits_type::copy(this->eback(),
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reinterpret_cast<char_type*>
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(_M_ext_buf), __ilen);
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_M_ext_next = _M_ext_buf + __ilen;
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}
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else
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__ilen = __iend - this->eback();
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// _M_codecvt->in may return error while __ilen > 0: this is
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// ok, and actually occurs in case of mixed encodings (e.g.,
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// XML files).
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if (__r == codecvt_base::error)
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break;
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__rlen = 1;
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}
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while (__ilen == 0 && !__got_eof);
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}
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if (__ilen > 0)
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{
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_M_set_buffer(__ilen);
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_M_reading = true;
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__ret = traits_type::to_int_type(*this->gptr());
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}
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else if (__got_eof)
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{
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// If the actual end of file is reached, set 'uncommitted'
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// mode, thus allowing an immediate write without an
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// intervening seek.
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_M_set_buffer(-1);
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_M_reading = false;
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// However, reaching it while looping on partial means that
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// the file has got an incomplete character.
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if (__r == codecvt_base::partial)
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__throw_ios_failure(__N("basic_filebuf::underflow "
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"incomplete character in file"));
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}
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else if (__r == codecvt_base::error)
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__throw_ios_failure(__N("basic_filebuf::underflow "
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"invalid byte sequence in file"));
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else
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__throw_ios_failure(__N("basic_filebuf::underflow "
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"error reading the file"));
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}
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return __ret;
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}
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template<typename _CharT, typename _Traits>
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typename basic_filebuf<_CharT, _Traits>::int_type
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basic_filebuf<_CharT, _Traits>::
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pbackfail(int_type __i)
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{
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int_type __ret = traits_type::eof();
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const bool __testin = _M_mode & ios_base::in;
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if (__testin)
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{
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if (_M_writing)
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{
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if (overflow() == traits_type::eof())
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return __ret;
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_M_set_buffer(-1);
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_M_writing = false;
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}
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// Remember whether the pback buffer is active, otherwise below
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// we may try to store in it a second char (libstdc++/9761).
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const bool __testpb = _M_pback_init;
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const bool __testeof = traits_type::eq_int_type(__i, __ret);
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int_type __tmp;
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if (this->eback() < this->gptr())
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{
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this->gbump(-1);
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__tmp = traits_type::to_int_type(*this->gptr());
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}
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else if (this->seekoff(-1, ios_base::cur) != pos_type(off_type(-1)))
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{
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__tmp = this->underflow();
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if (traits_type::eq_int_type(__tmp, __ret))
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return __ret;
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}
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else
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{
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// At the beginning of the buffer, need to make a
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// putback position available. But the seek may fail
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// (f.i., at the beginning of a file, see
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// libstdc++/9439) and in that case we return
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// traits_type::eof().
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return __ret;
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}
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// Try to put back __i into input sequence in one of three ways.
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// Order these tests done in is unspecified by the standard.
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if (!__testeof && traits_type::eq_int_type(__i, __tmp))
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__ret = __i;
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else if (__testeof)
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__ret = traits_type::not_eof(__i);
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else if (!__testpb)
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{
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_M_create_pback();
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_M_reading = true;
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*this->gptr() = traits_type::to_char_type(__i);
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__ret = __i;
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}
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}
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return __ret;
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}
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template<typename _CharT, typename _Traits>
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typename basic_filebuf<_CharT, _Traits>::int_type
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basic_filebuf<_CharT, _Traits>::
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overflow(int_type __c)
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{
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int_type __ret = traits_type::eof();
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const bool __testeof = traits_type::eq_int_type(__c, __ret);
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const bool __testout = _M_mode & ios_base::out;
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if (__testout)
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{
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if (_M_reading)
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{
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_M_destroy_pback();
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const int __gptr_off = _M_get_ext_pos(_M_state_last);
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if (_M_seek(__gptr_off, ios_base::cur, _M_state_last)
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== pos_type(off_type(-1)))
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return __ret;
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}
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if (this->pbase() < this->pptr())
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{
|
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// If appropriate, append the overflow char.
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if (!__testeof)
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{
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*this->pptr() = traits_type::to_char_type(__c);
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this->pbump(1);
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}
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// Convert pending sequence to external representation,
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// and output.
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if (_M_convert_to_external(this->pbase(),
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this->pptr() - this->pbase()))
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{
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_M_set_buffer(0);
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__ret = traits_type::not_eof(__c);
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}
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}
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else if (_M_buf_size > 1)
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{
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// Overflow in 'uncommitted' mode: set _M_writing, set
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// the buffer to the initial 'write' mode, and put __c
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// into the buffer.
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_M_set_buffer(0);
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_M_writing = true;
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if (!__testeof)
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{
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*this->pptr() = traits_type::to_char_type(__c);
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this->pbump(1);
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}
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__ret = traits_type::not_eof(__c);
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}
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else
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{
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// Unbuffered.
|
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char_type __conv = traits_type::to_char_type(__c);
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if (__testeof || _M_convert_to_external(&__conv, 1))
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{
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_M_writing = true;
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__ret = traits_type::not_eof(__c);
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}
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}
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}
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return __ret;
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}
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template<typename _CharT, typename _Traits>
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bool
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basic_filebuf<_CharT, _Traits>::
|
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_M_convert_to_external(_CharT* __ibuf, streamsize __ilen)
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|
{
|
|
// Sizes of external and pending output.
|
|
streamsize __elen;
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streamsize __plen;
|
|
if (__check_facet(_M_codecvt).always_noconv())
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{
|
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__elen = _M_file.xsputn(reinterpret_cast<char*>(__ibuf), __ilen);
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__plen = __ilen;
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}
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|
else
|
|
{
|
|
// Worst-case number of external bytes needed.
|
|
// XXX Not done encoding() == -1.
|
|
streamsize __blen = __ilen * _M_codecvt->max_length();
|
|
char* __buf = static_cast<char*>(__builtin_alloca(__blen));
|
|
|
|
char* __bend;
|
|
const char_type* __iend;
|
|
codecvt_base::result __r;
|
|
__r = _M_codecvt->out(_M_state_cur, __ibuf, __ibuf + __ilen,
|
|
__iend, __buf, __buf + __blen, __bend);
|
|
|
|
if (__r == codecvt_base::ok || __r == codecvt_base::partial)
|
|
__blen = __bend - __buf;
|
|
else if (__r == codecvt_base::noconv)
|
|
{
|
|
// Same as the always_noconv case above.
|
|
__buf = reinterpret_cast<char*>(__ibuf);
|
|
__blen = __ilen;
|
|
}
|
|
else
|
|
__throw_ios_failure(__N("basic_filebuf::_M_convert_to_external "
|
|
"conversion error"));
|
|
|
|
__elen = _M_file.xsputn(__buf, __blen);
|
|
__plen = __blen;
|
|
|
|
// Try once more for partial conversions.
|
|
if (__r == codecvt_base::partial && __elen == __plen)
|
|
{
|
|
const char_type* __iresume = __iend;
|
|
streamsize __rlen = this->pptr() - __iend;
|
|
__r = _M_codecvt->out(_M_state_cur, __iresume,
|
|
__iresume + __rlen, __iend, __buf,
|
|
__buf + __blen, __bend);
|
|
if (__r != codecvt_base::error)
|
|
{
|
|
__rlen = __bend - __buf;
|
|
__elen = _M_file.xsputn(__buf, __rlen);
|
|
__plen = __rlen;
|
|
}
|
|
else
|
|
__throw_ios_failure(__N("basic_filebuf::_M_convert_to_external "
|
|
"conversion error"));
|
|
}
|
|
}
|
|
return __elen == __plen;
|
|
}
|
|
|
|
template<typename _CharT, typename _Traits>
|
|
streamsize
|
|
basic_filebuf<_CharT, _Traits>::
|
|
xsgetn(_CharT* __s, streamsize __n)
|
|
{
|
|
// Clear out pback buffer before going on to the real deal...
|
|
streamsize __ret = 0;
|
|
if (_M_pback_init)
|
|
{
|
|
if (__n > 0 && this->gptr() == this->eback())
|
|
{
|
|
*__s++ = *this->gptr(); // emulate non-underflowing sbumpc
|
|
this->gbump(1);
|
|
__ret = 1;
|
|
--__n;
|
|
}
|
|
_M_destroy_pback();
|
|
}
|
|
else if (_M_writing)
|
|
{
|
|
if (overflow() == traits_type::eof())
|
|
return __ret;
|
|
_M_set_buffer(-1);
|
|
_M_writing = false;
|
|
}
|
|
|
|
// Optimization in the always_noconv() case, to be generalized in the
|
|
// future: when __n > __buflen we read directly instead of using the
|
|
// buffer repeatedly.
|
|
const bool __testin = _M_mode & ios_base::in;
|
|
const streamsize __buflen = _M_buf_size > 1 ? _M_buf_size - 1 : 1;
|
|
|
|
if (__n > __buflen && __check_facet(_M_codecvt).always_noconv()
|
|
&& __testin)
|
|
{
|
|
// First, copy the chars already present in the buffer.
|
|
const streamsize __avail = this->egptr() - this->gptr();
|
|
if (__avail != 0)
|
|
{
|
|
traits_type::copy(__s, this->gptr(), __avail);
|
|
__s += __avail;
|
|
this->setg(this->eback(), this->gptr() + __avail,
|
|
this->egptr());
|
|
__ret += __avail;
|
|
__n -= __avail;
|
|
}
|
|
|
|
// Need to loop in case of short reads (relatively common
|
|
// with pipes).
|
|
streamsize __len;
|
|
for (;;)
|
|
{
|
|
__len = _M_file.xsgetn(reinterpret_cast<char*>(__s),
|
|
__n);
|
|
if (__len == -1)
|
|
__throw_ios_failure(__N("basic_filebuf::xsgetn "
|
|
"error reading the file"));
|
|
if (__len == 0)
|
|
break;
|
|
|
|
__n -= __len;
|
|
__ret += __len;
|
|
if (__n == 0)
|
|
break;
|
|
|
|
__s += __len;
|
|
}
|
|
|
|
if (__n == 0)
|
|
{
|
|
_M_set_buffer(0);
|
|
_M_reading = true;
|
|
}
|
|
else if (__len == 0)
|
|
{
|
|
// If end of file is reached, set 'uncommitted'
|
|
// mode, thus allowing an immediate write without
|
|
// an intervening seek.
|
|
_M_set_buffer(-1);
|
|
_M_reading = false;
|
|
}
|
|
}
|
|
else
|
|
__ret += __streambuf_type::xsgetn(__s, __n);
|
|
|
|
return __ret;
|
|
}
|
|
|
|
template<typename _CharT, typename _Traits>
|
|
streamsize
|
|
basic_filebuf<_CharT, _Traits>::
|
|
xsputn(const _CharT* __s, streamsize __n)
|
|
{
|
|
streamsize __ret = 0;
|
|
// Optimization in the always_noconv() case, to be generalized in the
|
|
// future: when __n is sufficiently large we write directly instead of
|
|
// using the buffer.
|
|
const bool __testout = _M_mode & ios_base::out;
|
|
if (__check_facet(_M_codecvt).always_noconv()
|
|
&& __testout && !_M_reading)
|
|
{
|
|
// Measurement would reveal the best choice.
|
|
const streamsize __chunk = 1ul << 10;
|
|
streamsize __bufavail = this->epptr() - this->pptr();
|
|
|
|
// Don't mistake 'uncommitted' mode buffered with unbuffered.
|
|
if (!_M_writing && _M_buf_size > 1)
|
|
__bufavail = _M_buf_size - 1;
|
|
|
|
const streamsize __limit = std::min(__chunk, __bufavail);
|
|
if (__n >= __limit)
|
|
{
|
|
const streamsize __buffill = this->pptr() - this->pbase();
|
|
const char* __buf = reinterpret_cast<const char*>(this->pbase());
|
|
__ret = _M_file.xsputn_2(__buf, __buffill,
|
|
reinterpret_cast<const char*>(__s),
|
|
__n);
|
|
if (__ret == __buffill + __n)
|
|
{
|
|
_M_set_buffer(0);
|
|
_M_writing = true;
|
|
}
|
|
if (__ret > __buffill)
|
|
__ret -= __buffill;
|
|
else
|
|
__ret = 0;
|
|
}
|
|
else
|
|
__ret = __streambuf_type::xsputn(__s, __n);
|
|
}
|
|
else
|
|
__ret = __streambuf_type::xsputn(__s, __n);
|
|
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())
|
|
{
|
|
if (__s == 0 && __n == 0)
|
|
_M_buf_size = 1;
|
|
else if (__s && __n > 0)
|
|
{
|
|
// This is implementation-defined behavior, and assumes that
|
|
// an external char_type array of length __n exists and has
|
|
// been pre-allocated. If this is not the case, things will
|
|
// quickly blow up. When __n > 1, __n - 1 positions will be
|
|
// used for the get area, __n - 1 for the put area and 1
|
|
// position to host the overflow char of a full put area.
|
|
// When __n == 1, 1 position will be used for the get area
|
|
// and 0 for the put area, as in the unbuffered case above.
|
|
_M_buf = __s;
|
|
_M_buf_size = __n;
|
|
}
|
|
}
|
|
return this;
|
|
}
|
|
|
|
|
|
// According to 27.8.1.4 p11 - 13, seekoff should ignore the last
|
|
// argument (of type openmode).
|
|
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)
|
|
{
|
|
int __width = 0;
|
|
if (_M_codecvt)
|
|
__width = _M_codecvt->encoding();
|
|
if (__width < 0)
|
|
__width = 0;
|
|
|
|
pos_type __ret = pos_type(off_type(-1));
|
|
const bool __testfail = __off != 0 && __width <= 0;
|
|
if (this->is_open() && !__testfail)
|
|
{
|
|
// tellg and tellp queries do not affect any state, unless
|
|
// ! always_noconv and the put sequence is not empty.
|
|
// In that case, determining the position requires converting the
|
|
// put sequence. That doesn't use ext_buf, so requires a flush.
|
|
bool __no_movement = __way == ios_base::cur && __off == 0
|
|
&& (!_M_writing || _M_codecvt->always_noconv());
|
|
|
|
// Ditch any pback buffers to avoid confusion.
|
|
if (!__no_movement)
|
|
_M_destroy_pback();
|
|
|
|
// Correct state at destination. Note that this is the correct
|
|
// state for the current position during output, because
|
|
// codecvt::unshift() returns the state to the initial state.
|
|
// This is also the correct state at the end of the file because
|
|
// an unshift sequence should have been written at the end.
|
|
__state_type __state = _M_state_beg;
|
|
off_type __computed_off = __off * __width;
|
|
if (_M_reading && __way == ios_base::cur)
|
|
{
|
|
__state = _M_state_last;
|
|
__computed_off += _M_get_ext_pos(__state);
|
|
}
|
|
if (!__no_movement)
|
|
__ret = _M_seek(__computed_off, __way, __state);
|
|
else
|
|
{
|
|
if (_M_writing)
|
|
__computed_off = this->pptr() - this->pbase();
|
|
|
|
off_type __file_off = _M_file.seekoff(0, ios_base::cur);
|
|
if (__file_off != off_type(-1))
|
|
{
|
|
__ret = __file_off + __computed_off;
|
|
__ret.state(__state);
|
|
}
|
|
}
|
|
}
|
|
return __ret;
|
|
}
|
|
|
|
// _GLIBCXX_RESOLVE_LIB_DEFECTS
|
|
// 171. Strange seekpos() semantics due to joint position
|
|
// According to the resolution of DR 171, seekpos should ignore the last
|
|
// argument (of type openmode).
|
|
template<typename _CharT, typename _Traits>
|
|
typename basic_filebuf<_CharT, _Traits>::pos_type
|
|
basic_filebuf<_CharT, _Traits>::
|
|
seekpos(pos_type __pos, ios_base::openmode)
|
|
{
|
|
pos_type __ret = pos_type(off_type(-1));
|
|
if (this->is_open())
|
|
{
|
|
// Ditch any pback buffers to avoid confusion.
|
|
_M_destroy_pback();
|
|
__ret = _M_seek(off_type(__pos), ios_base::beg, __pos.state());
|
|
}
|
|
return __ret;
|
|
}
|
|
|
|
template<typename _CharT, typename _Traits>
|
|
typename basic_filebuf<_CharT, _Traits>::pos_type
|
|
basic_filebuf<_CharT, _Traits>::
|
|
_M_seek(off_type __off, ios_base::seekdir __way, __state_type __state)
|
|
{
|
|
pos_type __ret = pos_type(off_type(-1));
|
|
if (_M_terminate_output())
|
|
{
|
|
off_type __file_off = _M_file.seekoff(__off, __way);
|
|
if (__file_off != off_type(-1))
|
|
{
|
|
_M_reading = false;
|
|
_M_writing = false;
|
|
_M_ext_next = _M_ext_end = _M_ext_buf;
|
|
_M_set_buffer(-1);
|
|
_M_state_cur = __state;
|
|
__ret = __file_off;
|
|
__ret.state(_M_state_cur);
|
|
}
|
|
}
|
|
return __ret;
|
|
}
|
|
|
|
// Returns the distance from the end of the ext buffer to the point
|
|
// corresponding to gptr(). This is a negative value. Updates __state
|
|
// from eback() correspondence to gptr().
|
|
template<typename _CharT, typename _Traits>
|
|
int basic_filebuf<_CharT, _Traits>::
|
|
_M_get_ext_pos(__state_type& __state)
|
|
{
|
|
if (_M_codecvt->always_noconv())
|
|
return this->gptr() - this->egptr();
|
|
else
|
|
{
|
|
// Calculate offset from _M_ext_buf that corresponds to
|
|
// gptr(). Precondition: __state == _M_state_last, which
|
|
// corresponds to eback().
|
|
const int __gptr_off =
|
|
_M_codecvt->length(__state, _M_ext_buf, _M_ext_next,
|
|
this->gptr() - this->eback());
|
|
return _M_ext_buf + __gptr_off - _M_ext_end;
|
|
}
|
|
}
|
|
|
|
template<typename _CharT, typename _Traits>
|
|
bool
|
|
basic_filebuf<_CharT, _Traits>::
|
|
_M_terminate_output()
|
|
{
|
|
// Part one: update the output sequence.
|
|
bool __testvalid = true;
|
|
if (this->pbase() < this->pptr())
|
|
{
|
|
const int_type __tmp = this->overflow();
|
|
if (traits_type::eq_int_type(__tmp, traits_type::eof()))
|
|
__testvalid = false;
|
|
}
|
|
|
|
// Part two: output unshift sequence.
|
|
if (_M_writing && !__check_facet(_M_codecvt).always_noconv()
|
|
&& __testvalid)
|
|
{
|
|
// Note: this value is arbitrary, since there is no way to
|
|
// get the length of the unshift sequence from codecvt,
|
|
// without calling unshift.
|
|
const size_t __blen = 128;
|
|
char __buf[__blen];
|
|
codecvt_base::result __r;
|
|
streamsize __ilen = 0;
|
|
|
|
do
|
|
{
|
|
char* __next;
|
|
__r = _M_codecvt->unshift(_M_state_cur, __buf,
|
|
__buf + __blen, __next);
|
|
if (__r == codecvt_base::error)
|
|
__testvalid = false;
|
|
else if (__r == codecvt_base::ok ||
|
|
__r == codecvt_base::partial)
|
|
{
|
|
__ilen = __next - __buf;
|
|
if (__ilen > 0)
|
|
{
|
|
const streamsize __elen = _M_file.xsputn(__buf, __ilen);
|
|
if (__elen != __ilen)
|
|
__testvalid = false;
|
|
}
|
|
}
|
|
}
|
|
while (__r == codecvt_base::partial && __ilen > 0 && __testvalid);
|
|
|
|
if (__testvalid)
|
|
{
|
|
// This second call to overflow() is required by the standard,
|
|
// but it's not clear why it's needed, since the output buffer
|
|
// should be empty by this point (it should have been emptied
|
|
// in the first call to overflow()).
|
|
const int_type __tmp = this->overflow();
|
|
if (traits_type::eq_int_type(__tmp, traits_type::eof()))
|
|
__testvalid = false;
|
|
}
|
|
}
|
|
return __testvalid;
|
|
}
|
|
|
|
template<typename _CharT, typename _Traits>
|
|
int
|
|
basic_filebuf<_CharT, _Traits>::
|
|
sync()
|
|
{
|
|
// Make sure that the internal buffer resyncs its idea of
|
|
// the file position with the external file.
|
|
int __ret = 0;
|
|
if (this->pbase() < this->pptr())
|
|
{
|
|
const int_type __tmp = this->overflow();
|
|
if (traits_type::eq_int_type(__tmp, traits_type::eof()))
|
|
__ret = -1;
|
|
}
|
|
return __ret;
|
|
}
|
|
|
|
template<typename _CharT, typename _Traits>
|
|
void
|
|
basic_filebuf<_CharT, _Traits>::
|
|
imbue(const locale& __loc)
|
|
{
|
|
bool __testvalid = true;
|
|
|
|
const __codecvt_type* _M_codecvt_tmp = 0;
|
|
if (__builtin_expect(has_facet<__codecvt_type>(__loc), true))
|
|
_M_codecvt_tmp = &use_facet<__codecvt_type>(__loc);
|
|
|
|
if (this->is_open())
|
|
{
|
|
// encoding() == -1 is ok only at the beginning.
|
|
if ((_M_reading || _M_writing)
|
|
&& __check_facet(_M_codecvt).encoding() == -1)
|
|
__testvalid = false;
|
|
else
|
|
{
|
|
if (_M_reading)
|
|
{
|
|
if (__check_facet(_M_codecvt).always_noconv())
|
|
{
|
|
if (_M_codecvt_tmp
|
|
&& !__check_facet(_M_codecvt_tmp).always_noconv())
|
|
__testvalid = this->seekoff(0, ios_base::cur, _M_mode)
|
|
!= pos_type(off_type(-1));
|
|
}
|
|
else
|
|
{
|
|
// External position corresponding to gptr().
|
|
_M_ext_next = _M_ext_buf
|
|
+ _M_codecvt->length(_M_state_last, _M_ext_buf,
|
|
_M_ext_next,
|
|
this->gptr() - this->eback());
|
|
const streamsize __remainder = _M_ext_end - _M_ext_next;
|
|
if (__remainder)
|
|
__builtin_memmove(_M_ext_buf, _M_ext_next, __remainder);
|
|
|
|
_M_ext_next = _M_ext_buf;
|
|
_M_ext_end = _M_ext_buf + __remainder;
|
|
_M_set_buffer(-1);
|
|
_M_state_last = _M_state_cur = _M_state_beg;
|
|
}
|
|
}
|
|
else if (_M_writing && (__testvalid = _M_terminate_output()))
|
|
_M_set_buffer(-1);
|
|
}
|
|
}
|
|
|
|
if (__testvalid)
|
|
_M_codecvt = _M_codecvt_tmp;
|
|
else
|
|
_M_codecvt = 0;
|
|
}
|
|
|
|
// Inhibit implicit instantiations for required instantiations,
|
|
// which are defined via explicit instantiations elsewhere.
|
|
// NB: This syntax is a GNU extension.
|
|
#if _GLIBCXX_EXTERN_TEMPLATE
|
|
extern template class basic_filebuf<char>;
|
|
extern template class basic_ifstream<char>;
|
|
extern template class basic_ofstream<char>;
|
|
extern template class basic_fstream<char>;
|
|
|
|
#ifdef _GLIBCXX_USE_WCHAR_T
|
|
extern template class basic_filebuf<wchar_t>;
|
|
extern template class basic_ifstream<wchar_t>;
|
|
extern template class basic_ofstream<wchar_t>;
|
|
extern template class basic_fstream<wchar_t>;
|
|
#endif
|
|
#endif
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace
|
|
|
|
#endif
|