| // std::codecvt implementation details, generic version -*- C++ -*- |
| |
| // Copyright (C) 2002-2021 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 3, 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. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| // |
| // ISO C++ 14882: 22.2.1.5 - Template class codecvt |
| // |
| |
| // Written by Benjamin Kosnik <bkoz@redhat.com> |
| |
| #include <locale> |
| #include <cstdlib> // For MB_CUR_MAX |
| #include <climits> // For MB_LEN_MAX |
| #include <cstring> |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| // 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 necessary 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(0, __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_VERSION |
| } // namespace |