gcc/libstdc++-v3/include/bits/codecvt.h
Benjamin Kosnik 8ac2677fbb codecvt.h: Use __builtin_alloca.
2001-02-23  Benjamin Kosnik  <bkoz@redhat.com>

	* include/bits/codecvt.h: Use __builtin_alloca.
	* include/bits/ostream.tcc: Same.
	* include/bits/fstream.tcc: Same.

From-SVN: r40007
2001-02-23 19:22:04 +00:00

718 lines
22 KiB
C++

// Locale support (codecvt) -*- C++ -*-
// Copyright (C) 2000, 2001 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// 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
//
// Warning: this file is not meant for user inclusion. Use <locale>.
// Written by Benjamin Kosnik <bkoz@cygnus.com>
#ifndef _CPP_BITS_CODECVT_H
#define _CPP_BITS_CODECVT_H 1
#pragma GCC system_header
// XXX
// __enc_traits may need to move up the locale header hierarchy,
// depending on if ctype ends up using it.
#ifdef _GLIBCPP_USE_WCHAR_T
// Extensions to use icov for dealing with character encodings,
// including conversions and comparisons between various character
// sets. This object encapsulates data that may need to be shared between
// char_traits, codecvt and ctype.
#if _GLIBCPP_USE_SHADOW_HEADERS
using _C_legacy::CODESET;
#endif
class __enc_traits
{
public:
// Types:
// NB: A conversion descriptor subsumes and enhances the
// functionality of a simple state type such as mbstate_t.
typedef iconv_t __desc_type;
protected:
// Data Members:
// Max size of charset encoding name
static const int _S_max_size = 32;
// Name of internal character set encoding.
char _M_int_enc[_S_max_size];
// Name of external character set encoding.
char _M_ext_enc[_S_max_size];
// Conversion descriptor between external encoding to internal encoding.
__desc_type _M_in_desc;
// Conversion descriptor between internal encoding to external encoding.
__desc_type _M_out_desc;
// Details the byte-order marker for the external encoding, if necessary.
int _M_ext_bom;
// Details the byte-order marker for the internal encoding, if necessary.
int _M_int_bom;
public:
__enc_traits()
: _M_in_desc(0), _M_out_desc(0), _M_ext_bom(0), _M_int_bom(0)
{
// __intc_end = whatever we are using internally, which is
// UCS4 (linux)
// UCS2 == UNICODE (microsoft, java, aix, whatever...)
// XXX Currently don't know how to get this data from target system...
strcpy(_M_int_enc, "UCS4");
// __extc_end = external codeset in current locale
strcpy(_M_ext_enc, nl_langinfo(CODESET));
}
__enc_traits(const char* __int, const char* __ext, int __ibom = 0,
int __ebom = 0)
: _M_in_desc(0), _M_out_desc(0), _M_ext_bom(0), _M_int_bom(0)
{
strncpy(_M_int_enc, __int, _S_max_size);
strncpy(_M_ext_enc, __ext, _S_max_size);
}
// 21.1.2 traits typedefs
// p4
// typedef STATE_T state_type
// requires: state_type shall meet the requirements of
// CopyConstructible types (20.1.3)
__enc_traits(const __enc_traits& __obj)
{
strncpy(_M_int_enc, __obj._M_int_enc, _S_max_size);
strncpy(_M_ext_enc, __obj._M_ext_enc, _S_max_size);
_M_ext_bom = __obj._M_ext_bom;
_M_int_bom = __obj._M_int_bom;
}
~__enc_traits()
{
iconv_close(_M_in_desc);
iconv_close(_M_out_desc);
}
// Initializes
void
_M_init()
{
_M_in_desc = iconv_open(_M_int_enc, _M_ext_enc);
_M_out_desc = iconv_open(_M_ext_enc, _M_int_enc);
if (_M_out_desc == iconv_t(-1) || _M_in_desc == iconv_t(-1))
{
// XXX Extended error checking.
}
}
bool
_M_good()
{
return _M_out_desc && _M_in_desc
&& _M_out_desc != iconv_t(-1) && _M_in_desc != iconv_t(-1);
}
const __desc_type*
_M_get_in_descriptor()
{ return &_M_in_desc; }
const __desc_type*
_M_get_out_descriptor()
{ return &_M_out_desc; }
const char*
_M_get_internal_enc()
{ return _M_int_enc; }
const char*
_M_get_external_enc()
{ return _M_ext_enc; }
int
_M_get_external_bom()
{ return _M_ext_bom; }
int
_M_get_internal_bom()
{ return _M_int_bom; }
};
#endif //_GLIBCPP_USE_WCHAR_T
// 22.2.1.5 Template class codecvt
class codecvt_base
{
public:
enum result
{
ok,
partial,
error,
noconv
};
};
// Template class __codecvt_abstract_base
// NB: An abstract base class that fills in the public inlines, so
// that the specializations don't have to re-copy the public
// interface.
template<typename _InternT, typename _ExternT, typename _StateT>
class __codecvt_abstract_base
: public locale::facet, public codecvt_base
{
public:
// Types:
typedef codecvt_base::result result;
typedef _InternT intern_type;
typedef _ExternT extern_type;
typedef _StateT state_type;
// 22.2.1.5.1 codecvt members
result
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
{
return this->do_out(__state, __from, __from_end, __from_next,
__to, __to_end, __to_next);
}
result
unshift(state_type& __state, extern_type* __to, extern_type* __to_end,
extern_type*& __to_next) const
{ return this->do_unshift(__state, __to,__to_end,__to_next); }
result
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
{
return this->do_in(__state, __from, __from_end, __from_next,
__to, __to_end, __to_next);
}
int
encoding() const throw()
{ return this->do_encoding(); }
bool
always_noconv() const throw()
{ return this->do_always_noconv(); }
int
length(const state_type& __state, const extern_type* __from,
const extern_type* __end, size_t __max) const
{ return this->do_length(__state, __from, __end, __max); }
int
max_length() const throw()
{ return this->do_max_length(); }
protected:
explicit
__codecvt_abstract_base(size_t __refs = 0) : locale::facet(__refs) { }
virtual
~__codecvt_abstract_base() { }
virtual result
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 = 0;
virtual result
do_unshift(state_type& __state, extern_type* __to,
extern_type* __to_end, extern_type*& __to_next) const = 0;
virtual result
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 = 0;
virtual int
do_encoding() const throw() = 0;
virtual bool
do_always_noconv() const throw() = 0;
virtual int
do_length(const state_type&, const extern_type* __from,
const extern_type* __end, size_t __max) const = 0;
virtual int
do_max_length() const throw() = 0;
};
// 22.2.1.5 Template class codecvt
// NB: Generic, mostly useless implementation.
template<typename _InternT, typename _ExternT, typename _StateT>
class codecvt
: public __codecvt_abstract_base<_InternT, _ExternT, _StateT>
{
public:
// Types:
typedef codecvt_base::result result;
typedef _InternT intern_type;
typedef _ExternT extern_type;
typedef _StateT state_type;
// Data Members:
static locale::id id;
explicit
codecvt(size_t __refs = 0)
: __codecvt_abstract_base<_InternT,_ExternT,_StateT> (__refs) { }
protected:
virtual
~codecvt() { }
};
template<typename _InternT, typename _ExternT, typename _StateT>
locale::id codecvt<_InternT, _ExternT, _StateT>::id;
#ifdef _GLIBCPP_USE_WCHAR_T
// partial specialization
// This specialization takes advantage of iconv to provide code
// conversions between a large number of character encodings.
template<typename _InternT, typename _ExternT>
class codecvt<_InternT, _ExternT, __enc_traits>
: public __codecvt_abstract_base<_InternT, _ExternT, __enc_traits>
{
public:
// Types:
typedef codecvt_base::result result;
typedef _InternT intern_type;
typedef _ExternT extern_type;
typedef __enc_traits state_type;
typedef __enc_traits::__desc_type __desc_type;
typedef __enc_traits __enc_type;
// Data Members:
static locale::id id;
explicit
codecvt(size_t __refs = 0)
: __codecvt_abstract_base<intern_type, extern_type, state_type>(__refs)
{ }
explicit
codecvt(__enc_type* __enc, size_t __refs = 0)
: __codecvt_abstract_base<intern_type, extern_type, state_type>(__refs)
{ }
protected:
virtual
~codecvt() { }
virtual result
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;
virtual result
do_unshift(state_type& __state, extern_type* __to,
extern_type* __to_end, extern_type*& __to_next) const;
virtual result
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;
virtual int
do_encoding() const throw();
virtual bool
do_always_noconv() const throw();
virtual int
do_length(const state_type&, const extern_type* __from,
const extern_type* __end, size_t __max) const;
virtual int
do_max_length() const throw();
};
template<typename _InternT, typename _ExternT>
locale::id
codecvt<_InternT, _ExternT, __enc_traits>::id;
// This adaptor works around the signature problems of the second
// argument to iconv(): SUSv2 and others use 'const char**', but glibc 2.2
// uses 'char**', which is what the standard is (apparently) due to use
// in the future. Using this adaptor, g++ will do the work for us.
template<typename _T>
inline size_t
__iconv_adaptor(size_t(*iconv_func)(iconv_t, _T, size_t*, char**, size_t*),
iconv_t cd, char** inbuf, size_t* inbytesleft,
char** outbuf, size_t* outbytesleft)
{
return iconv_func(cd, (_T)inbuf, inbytesleft, outbuf, outbytesleft);
}
template<typename _InternT, typename _ExternT>
codecvt_base::result
codecvt<_InternT, _ExternT, __enc_traits>::
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 = error;
if (__state._M_good())
{
typedef state_type::__desc_type __desc_type;
const __desc_type* __desc = __state._M_get_out_descriptor();
const size_t __fmultiple = sizeof(intern_type) / sizeof(char);
size_t __flen = __fmultiple * (__from_end - __from);
const size_t __tmultiple = sizeof(extern_type) / sizeof(char);
size_t __tlen = __tmultiple * (__to_end - __to);
// Argument list for iconv specifies a byte sequence. Thus,
// all to/from arrays must be brutally casted to char*.
char* __cto = reinterpret_cast<char*>(__to);
char* __cfrom;
size_t __conv;
// Some encodings need a byte order marker as the first item
// in the byte stream, to designate endian-ness. The default
// value for the byte order marker is NULL, so if this is
// the case, it's not necessary and we can just go on our
// merry way.
int __int_bom = __state._M_get_internal_bom();
if (__int_bom)
{
size_t __size = __from_end - __from;
intern_type* __cfixed = static_cast<intern_type*>(__builtin_alloca(sizeof(intern_type) * (__size + 1)));
__cfixed[0] = static_cast<intern_type>(__int_bom);
char_traits<intern_type>::copy(__cfixed + 1, __from, __size);
__cfrom = reinterpret_cast<char*>(__cfixed);
__conv = __iconv_adaptor(iconv, *__desc, &__cfrom,
&__flen, &__cto, &__tlen);
}
else
{
intern_type* __cfixed = const_cast<intern_type*>(__from);
__cfrom = reinterpret_cast<char*>(__cfixed);
__conv = __iconv_adaptor(iconv, *__desc, &__cfrom,
&__flen, &__cto, &__tlen);
}
if (__conv != size_t(-1))
{
__from_next = reinterpret_cast<const intern_type*>(__cfrom);
__to_next = reinterpret_cast<extern_type*>(__cto);
__ret = ok;
}
else
{
if (__flen < __from_end - __from)
{
__from_next = reinterpret_cast<const intern_type*>(__cfrom);
__to_next = reinterpret_cast<extern_type*>(__cto);
__ret = partial;
}
else
__ret = error;
}
}
return __ret;
}
template<typename _InternT, typename _ExternT>
codecvt_base::result
codecvt<_InternT, _ExternT, __enc_traits>::
do_unshift(state_type& __state, extern_type* __to,
extern_type* __to_end, extern_type*& __to_next) const
{
result __ret = error;
if (__state._M_good())
{
typedef state_type::__desc_type __desc_type;
const __desc_type* __desc = __state._M_get_in_descriptor();
const size_t __tmultiple = sizeof(intern_type) / sizeof(char);
size_t __tlen = __tmultiple * (__to_end - __to);
// Argument list for iconv specifies a byte sequence. Thus,
// all to/from arrays must be brutally casted to char*.
char* __cto = reinterpret_cast<char*>(__to);
size_t __conv = __iconv_adaptor(iconv,*__desc, NULL, NULL,
&__cto, &__tlen);
if (__conv != size_t(-1))
{
__to_next = reinterpret_cast<extern_type*>(__cto);
if (__tlen == __tmultiple * (__to_end - __to))
__ret = noconv;
else if (__tlen == 0)
__ret = ok;
else
__ret = partial;
}
else
__ret = error;
}
return __ret;
}
template<typename _InternT, typename _ExternT>
codecvt_base::result
codecvt<_InternT, _ExternT, __enc_traits>::
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 = error;
if (__state._M_good())
{
typedef state_type::__desc_type __desc_type;
const __desc_type* __desc = __state._M_get_in_descriptor();
const size_t __fmultiple = sizeof(extern_type) / sizeof(char);
size_t __flen = __fmultiple * (__from_end - __from);
const size_t __tmultiple = sizeof(intern_type) / sizeof(char);
size_t __tlen = __tmultiple * (__to_end - __to);
// Argument list for iconv specifies a byte sequence. Thus,
// all to/from arrays must be brutally casted to char*.
char* __cto = reinterpret_cast<char*>(__to);
char* __cfrom;
size_t __conv;
// Some encodings need a byte order marker as the first item
// in the byte stream, to designate endian-ness. The default
// value for the byte order marker is NULL, so if this is
// the case, it's not necessary and we can just go on our
// merry way.
int __ext_bom = __state._M_get_external_bom();
if (__ext_bom)
{
size_t __size = __from_end - __from;
extern_type* __cfixed = (sizeof(extern_type) * (__size + 1));
__cfixed[0] = static_cast<extern_type>(__ext_bom);
char_traits<extern_type>::copy(__cfixed + 1, __from, __size);
__cfrom = reinterpret_cast<char*>(__cfixed);
__conv = __iconv_adaptor(iconv, *__desc, &__cfrom,
&__flen, &__cto, &__tlen);
}
else
{
extern_type* __cfixed = const_cast<extern_type*>(__from);
__cfrom = reinterpret_cast<char*>(__cfixed);
__conv = __iconv_adaptor(iconv, *__desc, &__cfrom,
&__flen, &__cto, &__tlen);
}
if (__conv != size_t(-1))
{
__from_next = reinterpret_cast<const extern_type*>(__cfrom);
__to_next = reinterpret_cast<intern_type*>(__cto);
__ret = ok;
}
else
{
if (__flen < __from_end - __from)
{
__from_next = reinterpret_cast<const extern_type*>(__cfrom);
__to_next = reinterpret_cast<intern_type*>(__cto);
__ret = partial;
}
else
__ret = error;
}
}
return __ret;
}
template<typename _InternT, typename _ExternT>
int
codecvt<_InternT, _ExternT, __enc_traits>::
do_encoding() const throw()
{ return 0; }
template<typename _InternT, typename _ExternT>
bool
codecvt<_InternT, _ExternT, __enc_traits>::
do_always_noconv() const throw()
{ return false; }
template<typename _InternT, typename _ExternT>
int
codecvt<_InternT, _ExternT, __enc_traits>::
do_length(const state_type& __state, const extern_type* __from,
const extern_type* __end, size_t __max) const
{ return min(__max, static_cast<size_t>(__end - __from)); }
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
// 74. Garbled text for codecvt::do_max_length
template<typename _InternT, typename _ExternT>
int
codecvt<_InternT, _ExternT, __enc_traits>::
do_max_length() const throw()
{ return 1; }
#endif
#endif /* _GLIBCPP_USE_WCHAR_T */
// codecvt<char, char, mbstate_t> required specialization
template<>
class codecvt<char, char, mbstate_t>
: public __codecvt_abstract_base<char, char, mbstate_t>
{
public:
// Types:
typedef char intern_type;
typedef char extern_type;
typedef mbstate_t state_type;
// Data Members:
static locale::id id;
explicit
codecvt(size_t __refs = 0);
protected:
virtual
~codecvt();
virtual result
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;
virtual result
do_unshift(state_type& __state, extern_type* __to,
extern_type* __to_end, extern_type*& __to_next) const;
virtual result
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;
virtual int
do_encoding() const throw();
virtual bool
do_always_noconv() const throw();
virtual int
do_length(const state_type&, const extern_type* __from,
const extern_type* __end, size_t __max) const;
virtual int
do_max_length() const throw();
};
#ifdef _GLIBCPP_USE_WCHAR_T
// codecvt<wchar_t, char, mbstate_t> required specialization
template<>
class codecvt<wchar_t, char, mbstate_t>
: public __codecvt_abstract_base<wchar_t, char, mbstate_t>
{
public:
// Types:
typedef wchar_t intern_type;
typedef char extern_type;
typedef mbstate_t state_type;
// Data Members:
static locale::id id;
explicit
codecvt(size_t __refs = 0);
protected:
virtual
~codecvt();
virtual result
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;
virtual result
do_unshift(state_type& __state,
extern_type* __to, extern_type* __to_end,
extern_type*& __to_next) const;
virtual result
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;
virtual
int do_encoding() const throw();
virtual
bool do_always_noconv() const throw();
virtual
int do_length(const state_type&, const extern_type* __from,
const extern_type* __end, size_t __max) const;
virtual int
do_max_length() const throw();
};
#endif //_GLIBCPP_USE_WCHAR_T
// 22.2.1.6 Template class codecvt_byname
template<typename _InternT, typename _ExternT, typename _StateT>
class codecvt_byname : public codecvt<_InternT, _ExternT, _StateT>
{
public:
explicit
codecvt_byname(const char*, size_t __refs = 0)
: codecvt<_InternT, _ExternT, _StateT>(__refs) { }
protected:
virtual
~codecvt_byname() { }
};
#endif // _CPP_BITS_CODECVT_H
// Local Variables:
// mode:c++
// End: