// std::codecvt implementation details, DragonFly version -*- C++ -*-
// Copyright (C) 2015-2023 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>
// Modified for DragonFly by John Marino <gnugcc@marino.st>
#include <locale>
#include <cstring>
#include <cstdlib> // For MB_CUR_MAX
#include <climits> // For MB_LEN_MAX
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;
state_type __tmp_state(__state);
__c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
// 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<size_t>(-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<size_t>(__to_end - __to_next))
__ret = partial;
else
{
memcpy(__to_next, __buf, __conv2);
__state = __tmp_state;
__to_next += __conv2;
++__from_next;
}
}
}
uselocale((locale_t)__old);
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;
state_type __tmp_state(__state);
__c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
// 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<const extern_type*>(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<size_t>(-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<size_t>(-1)
|| __conv == static_cast<size_t>(-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;
}
}
uselocale((locale_t)__old);
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;
__c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
if (MB_CUR_MAX == 1)
__ret = 1;
uselocale((locale_t)__old);
return __ret;
}
int
codecvt<wchar_t, char, mbstate_t>::
do_max_length() const throw()
{
__c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
// XXX Probably wrong for stateful encodings.
int __ret = MB_CUR_MAX;
uselocale((locale_t)__old);
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);
__c_locale __old = (__c_locale)uselocale((locale_t)_M_c_locale_codecvt);
// 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<wchar_t*>(__builtin_alloca(sizeof(wchar_t)
* __max));
while (__from < __end && __max)
{
const extern_type* __from_chunk_end;
__from_chunk_end = static_cast<const extern_type*>(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<size_t>(-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<size_t>(-1)
|| __conv == static_cast<size_t>(-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;
}
}
uselocale((locale_t)__old);
return __ret;
}
#endif
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace