// std::codecvt implementation details, GNU version -*- C++ -*- // Copyright (C) 2002-2020 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 // . // // ISO C++ 14882: 22.2.1.5 - Template class codecvt // // Written by Benjamin Kosnik #include #include // For MB_CUR_MAX #include // For MB_LEN_MAX #include namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION // Specializations. #ifdef _GLIBCXX_USE_WCHAR_T codecvt_base::result codecvt:: 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; state_type __tmp_state(__state); #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __c_locale __old = __uselocale(_M_c_locale_codecvt); #endif // wcsnrtombs is *very* fast but stops if encounters NUL characters: // in case we fall back to wcrtomb and then continue, in a loop. // NB: wcsnrtombs is a GNU extension for (__from_next = __from, __to_next = __to; __from_next < __from_end && __to_next < __to_end && __ret == ok;) { const intern_type* __from_chunk_end = wmemchr(__from_next, L'\0', __from_end - __from_next); if (!__from_chunk_end) __from_chunk_end = __from_end; __from = __from_next; const size_t __conv = wcsnrtombs(__to_next, &__from_next, __from_chunk_end - __from_next, __to_end - __to_next, &__state); if (__conv == static_cast(-1)) { // In case of error, in order to stop at the exact place we // have to start again from the beginning with a series of // wcrtomb. for (; __from < __from_next; ++__from) __to_next += wcrtomb(__to_next, *__from, &__tmp_state); __state = __tmp_state; __ret = error; } else if (__from_next && __from_next < __from_chunk_end) { __to_next += __conv; __ret = partial; } else { __from_next = __from_chunk_end; __to_next += __conv; } if (__from_next < __from_end && __ret == ok) { extern_type __buf[MB_LEN_MAX]; __tmp_state = __state; const size_t __conv2 = wcrtomb(__buf, *__from_next, &__tmp_state); if (__conv2 > static_cast(__to_end - __to_next)) __ret = partial; else { memcpy(__to_next, __buf, __conv2); __state = __tmp_state; __to_next += __conv2; ++__from_next; } } } #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __uselocale(__old); #endif return __ret; } codecvt_base::result codecvt:: 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; state_type __tmp_state(__state); #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __c_locale __old = __uselocale(_M_c_locale_codecvt); #endif // mbsnrtowcs is *very* fast but stops if encounters NUL characters: // in case we store a L'\0' and then continue, in a loop. // NB: mbsnrtowcs is a GNU extension for (__from_next = __from, __to_next = __to; __from_next < __from_end && __to_next < __to_end && __ret == ok;) { const extern_type* __from_chunk_end; __from_chunk_end = static_cast(memchr(__from_next, '\0', __from_end - __from_next)); if (!__from_chunk_end) __from_chunk_end = __from_end; __from = __from_next; size_t __conv = mbsnrtowcs(__to_next, &__from_next, __from_chunk_end - __from_next, __to_end - __to_next, &__state); if (__conv == static_cast(-1)) { // In case of error, in order to stop at the exact place we // have to start again from the beginning with a series of // mbrtowc. for (;; ++__to_next, __from += __conv) { __conv = mbrtowc(__to_next, __from, __from_end - __from, &__tmp_state); if (__conv == static_cast(-1) || __conv == static_cast(-2)) break; } __from_next = __from; __state = __tmp_state; __ret = error; } else if (__from_next && __from_next < __from_chunk_end) { // It is unclear what to return in this case (see DR 382). __to_next += __conv; __ret = partial; } else { __from_next = __from_chunk_end; __to_next += __conv; } if (__from_next < __from_end && __ret == ok) { if (__to_next < __to_end) { // XXX Probably wrong for stateful encodings __tmp_state = __state; ++__from_next; *__to_next++ = L'\0'; } else __ret = partial; } } #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __uselocale(__old); #endif return __ret; } int codecvt:: 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 __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __c_locale __old = __uselocale(_M_c_locale_codecvt); #endif if (MB_CUR_MAX == 1) __ret = 1; #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __uselocale(__old); #endif return __ret; } int codecvt:: do_max_length() const throw() { #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __c_locale __old = __uselocale(_M_c_locale_codecvt); #endif // XXX Probably wrong for stateful encodings. int __ret = MB_CUR_MAX; #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __uselocale(__old); #endif return __ret; } int codecvt:: 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); #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __c_locale __old = __uselocale(_M_c_locale_codecvt); #endif // mbsnrtowcs is *very* fast but stops if encounters NUL characters: // in case we advance past it and then continue, in a loop. // NB: mbsnrtowcs is a GNU extension // A dummy internal buffer is needed in order for mbsnrtocws to consider // its fourth parameter (it wouldn't with NULL as first parameter). wchar_t* __to = static_cast(__builtin_alloca(sizeof(wchar_t) * __max)); while (__from < __end && __max) { const extern_type* __from_chunk_end; __from_chunk_end = static_cast(memchr(__from, '\0', __end - __from)); if (!__from_chunk_end) __from_chunk_end = __end; const extern_type* __tmp_from = __from; size_t __conv = mbsnrtowcs(__to, &__from, __from_chunk_end - __from, __max, &__state); if (__conv == static_cast(-1)) { // In case of error, in order to stop at the exact place we // have to start again from the beginning with a series of // mbrtowc. for (__from = __tmp_from;; __from += __conv) { __conv = mbrtowc(0, __from, __end - __from, &__tmp_state); if (__conv == static_cast(-1) || __conv == static_cast(-2)) break; } __state = __tmp_state; __ret += __from - __tmp_from; break; } if (!__from) __from = __from_chunk_end; __ret += __from - __tmp_from; __max -= __conv; if (__from < __end && __max) { // XXX Probably wrong for stateful encodings __tmp_state = __state; ++__from; ++__ret; --__max; } } #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) __uselocale(__old); #endif return __ret; } #endif _GLIBCXX_END_NAMESPACE_VERSION } // namespace