// std::codecvt implementation details, generic version -*- C++ -*- // Copyright (C) 2002, 2005 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, // 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: 22.2.1.5 - Template class codecvt // // Written by Benjamin Kosnik <bkoz@redhat.com> #include <locale> _GLIBCXX_BEGIN_NAMESPACE(std) // Specializations. #ifdef _GLIBCXX_USE_WCHAR_T codecvt_base::result codecvt<wchar_t, char, mbstate_t>:: do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const { result __ret = ok; // The conversion must be done using a temporary destination buffer // since it is not possible to pass the size of the buffer to wcrtomb state_type __tmp_state(__state); // The conversion must be done by calling wcrtomb in a loop rather // than using wcsrtombs because wcsrtombs assumes that the input is // zero-terminated. // Either we can upper bound the total number of external characters to // something smaller than __to_end - __to or the conversion must be done // using a temporary destination buffer since it is not possible to // pass the size of the buffer to wcrtomb if (MB_CUR_MAX * (__from_end - __from) - (__to_end - __to) <= 0) while (__from < __from_end) { const size_t __conv = wcrtomb(__to, *__from, &__tmp_state); if (__conv == static_cast<size_t>(-1)) { __ret = error; break; } __state = __tmp_state; __to += __conv; __from++; } else { extern_type __buf[MB_LEN_MAX]; while (__from < __from_end && __to < __to_end) { const size_t __conv = wcrtomb(__buf, *__from, &__tmp_state); if (__conv == static_cast<size_t>(-1)) { __ret = error; break; } else if (__conv > static_cast<size_t>(__to_end - __to)) { __ret = partial; break; } memcpy(__to, __buf, __conv); __state = __tmp_state; __to += __conv; __from++; } } if (__ret == ok && __from < __from_end) __ret = partial; __from_next = __from; __to_next = __to; return __ret; } codecvt_base::result codecvt<wchar_t, char, mbstate_t>:: do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const { result __ret = ok; // This temporary state object is neccessary so __state won't be modified // if [__from, __from_end) is a partial multibyte character. state_type __tmp_state(__state); // Conversion must be done by calling mbrtowc in a loop rather than // by calling mbsrtowcs because mbsrtowcs assumes that the input // sequence is zero-terminated. while (__from < __from_end && __to < __to_end) { size_t __conv = mbrtowc(__to, __from, __from_end - __from, &__tmp_state); if (__conv == static_cast<size_t>(-1)) { __ret = error; break; } else if (__conv == static_cast<size_t>(-2)) { // It is unclear what to return in this case (see DR 382). __ret = partial; break; } else if (__conv == 0) { // XXX Probably wrong for stateful encodings __conv = 1; *__to = L'\0'; } __state = __tmp_state; __to++; __from += __conv; } // It is not clear that __from < __from_end implies __ret != ok // (see DR 382). if (__ret == ok && __from < __from_end) __ret = partial; __from_next = __from; __to_next = __to; return __ret; } int codecvt<wchar_t, char, mbstate_t>:: do_encoding() const throw() { // XXX This implementation assumes that the encoding is // stateless and is either single-byte or variable-width. int __ret = 0; if (MB_CUR_MAX == 1) __ret = 1; return __ret; } int codecvt<wchar_t, char, mbstate_t>:: do_max_length() const throw() { // XXX Probably wrong for stateful encodings. int __ret = MB_CUR_MAX; return __ret; } int codecvt<wchar_t, char, mbstate_t>:: do_length(state_type& __state, const extern_type* __from, const extern_type* __end, size_t __max) const { int __ret = 0; state_type __tmp_state(__state); while (__from < __end && __max) { size_t __conv = mbrtowc(NULL, __from, __end - __from, &__tmp_state); if (__conv == static_cast<size_t>(-1)) { // Invalid source character break; } else if (__conv == static_cast<size_t>(-2)) { // Remainder of input does not form a complete destination // character. break; } else if (__conv == 0) { // XXX Probably wrong for stateful encodings __conv = 1; } __state = __tmp_state; __from += __conv; __ret += __conv; __max--; } return __ret; } #endif _GLIBCXX_END_NAMESPACE