lyx_mirror/src/support/docstream.cpp
2017-12-15 23:28:33 -05:00

513 lines
14 KiB
C++

/**
* \file docstream.cpp
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Georg Baum
*
* Full author contact details are available in file CREDITS.
*/
#include <config.h>
#include "support/docstream.h"
#include "support/lstrings.h"
#include "support/unicode.h"
#include <algorithm>
#include <cerrno>
#include <cstdio>
#include <cstring>
#include <iconv.h>
#include <locale>
using namespace std;
using lyx::ucs4_codeset;
#if defined(_MSC_VER) && (_MSC_VER >= 1600)
std::locale::id numpunct<lyx::char_type>::id;
namespace std {
// Implementation of numpunct<lyx::char_type> defined in numpunct_lyx_char_type.h
typedef basic_string<lyx::char_type> string_type;
string_type numpunct<lyx::char_type>::truename() const
{
return lyx::from_ascii(numpunct<char>::truename());
}
string_type numpunct<lyx::char_type>::falsename() const
{
return lyx::from_ascii(numpunct<char>::falsename());
}
} // namespace std
#endif // _MSC_VER >= 1600
namespace {
// We use C IO throughout this file, because the facets might be used with
// lyxerr in the future.
/// codecvt facet for conversion of UCS4 (internal representation) to UTF8
/// (external representation) or vice versa
class iconv_codecvt_facet : public codecvt<lyx::char_type, char, mbstate_t>
{
typedef codecvt<lyx::char_type, char, mbstate_t> base;
public:
/// Constructor. You have to specify with \p inout whether you want
/// to use this facet only for input, only for output or for both.
explicit iconv_codecvt_facet(string const & encoding = "UTF-8",
ios_base::openmode inout = ios_base::in | ios_base::out,
size_t refs = 0)
: base(refs), encoding_(encoding)
{
if (inout & ios_base::in) {
in_cd_ = iconv_open(ucs4_codeset, encoding.c_str());
if (in_cd_ == (iconv_t)(-1)) {
fprintf(stderr, "Error %d returned from iconv_open(in_cd_): %s\n",
errno, strerror(errno));
fflush(stderr);
throw lyx::iconv_codecvt_facet_exception();
}
} else
in_cd_ = (iconv_t)(-1);
if (inout & ios_base::out) {
out_cd_ = iconv_open(encoding.c_str(), ucs4_codeset);
if (out_cd_ == (iconv_t)(-1)) {
fprintf(stderr, "Error %d returned from iconv_open(out_cd_): %s\n",
errno, strerror(errno));
fflush(stderr);
throw lyx::iconv_codecvt_facet_exception();
}
} else
out_cd_ = (iconv_t)(-1);
}
string const & encoding() const { return encoding_; }
protected:
virtual ~iconv_codecvt_facet()
{
if (in_cd_ != (iconv_t)(-1))
if (iconv_close(in_cd_) == -1) {
fprintf(stderr, "Error %d returned from iconv_close(in_cd_): %s\n",
errno, strerror(errno));
fflush(stderr);
}
if (out_cd_ != (iconv_t)(-1))
if (iconv_close(out_cd_) == -1) {
fprintf(stderr, "Error %d returned from iconv_close(out_cd_): %s\n",
errno, strerror(errno));
fflush(stderr);
}
}
virtual result do_out(state_type &, intern_type const * from,
intern_type const * from_end, intern_type const *& from_next,
extern_type * to, extern_type * to_end,
extern_type *& to_next) const
{
#define WORKAROUND_ICONV_BUG 1
#if WORKAROUND_ICONV_BUG
// Due to a bug in some iconv versions, when the last char
// in the buffer is a wide char and the output encoding is
// ISO-2022-JP and we are going to switch to another encoding,
// the appropriate escape sequence for changing the character
// set is not output (see bugs 5216, 5280, and also 5489).
// As a workaround, we append a nul char in order to force
// a switch to ASCII, and then remove it from output after
// the conversion.
intern_type * from_new = 0;
intern_type const * from_old = from;
size_t extra = 0;
if (*(from_end - 1) >= 0x80 && encoding_ == "ISO-2022-JP") {
size_t len = from_end - from;
from_new = new intern_type[len + 1];
memcpy(from_new, from, len * sizeof(intern_type));
from_new[len] = 0;
from_end = from_new + len + 1;
from = from_new;
extra = 1;
}
#endif
size_t inbytesleft = (from_end - from) * sizeof(intern_type);
size_t outbytesleft = (to_end - to) * sizeof(extern_type);
#if WORKAROUND_ICONV_BUG
outbytesleft += extra * sizeof(extern_type);
#endif
from_next = from;
to_next = to;
result const retval = do_iconv(out_cd_,
reinterpret_cast<char const **>(&from_next),
&inbytesleft, &to_next, &outbytesleft);
#if WORKAROUND_ICONV_BUG
// Remove from output the nul char that we inserted at the end
// of the input buffer in order to circumvent an iconv bug.
if (from_new) {
--to_next;
--from_next;
from_next = from_old + (from_next - from);
from = from_old;
delete[] from_new;
}
#endif
if (retval == base::error) {
fprintf(stderr,
"Error %d returned from iconv when converting from %s to %s: %s\n",
errno, ucs4_codeset, encoding_.c_str(),
strerror(errno));
fputs("Converted input:", stderr);
for (intern_type const * i = from; i < from_next; ++i) {
unsigned int const c = *i;
fprintf(stderr, " 0x%04x", c);
}
unsigned int const c = *from_next;
fprintf(stderr, "\nStopped at: 0x%04x\n", c);
fputs("Unconverted input:", stderr);
for (intern_type const * i = from_next + 1; i < from_end; ++i) {
unsigned int const cc = *i;
fprintf(stderr, " 0x%04x", cc);
}
fputs("\nConverted output:", stderr);
for (extern_type const * i = to; i < to_next; ++i) {
// extern_type may be signed, avoid output of
// something like 0xffffffc2
unsigned int const cc =
*reinterpret_cast<unsigned char const *>(i);
fprintf(stderr, " 0x%02x", cc);
}
fputc('\n', stderr);
fflush(stderr);
}
return retval;
}
virtual result do_unshift(state_type &, extern_type * to,
extern_type *, extern_type *& to_next) const
{
// utf8 does not use shifting
to_next = to;
return base::noconv;
}
virtual result do_in(state_type &,
extern_type const * from, extern_type const * from_end,
extern_type const *& from_next,
intern_type * to, intern_type * to_end,
intern_type *& to_next) const
{
size_t inbytesleft = (from_end - from) * sizeof(extern_type);
size_t outbytesleft = (to_end - to) * sizeof(intern_type);
from_next = from;
to_next = to;
result const retval = do_iconv(in_cd_, &from_next, &inbytesleft,
reinterpret_cast<char **>(&to_next),
&outbytesleft);
if (retval == base::error) {
fprintf(stderr,
"Error %d returned from iconv when converting from %s to %s: %s\n",
errno, encoding_.c_str(), ucs4_codeset,
strerror(errno));
fputs("Converted input:", stderr);
for (extern_type const * i = from; i < from_next; ++i) {
// extern_type may be signed, avoid output of
// something like 0xffffffc2
unsigned int const c =
*reinterpret_cast<unsigned char const *>(i);
fprintf(stderr, " 0x%02x", c);
}
unsigned int const c =
*reinterpret_cast<unsigned char const *>(from_next);
fprintf(stderr, "\nStopped at: 0x%02x\n", c);
fputs("Unconverted input:", stderr);
for (extern_type const * i = from_next + 1; i < from_end; ++i) {
unsigned int const cc =
*reinterpret_cast<unsigned char const *>(i);
fprintf(stderr, " 0x%02x", cc);
}
fputs("\nConverted output:", stderr);
for (intern_type const * i = to; i < to_next; ++i) {
unsigned int const cc = *i;
fprintf(stderr, " 0x%02x", cc);
}
fputc('\n', stderr);
fflush(stderr);
}
return retval;
}
virtual int do_encoding() const throw()
{
return 0;
}
virtual bool do_always_noconv() const throw()
{
return false;
}
virtual int do_length(state_type & /*state*/, extern_type const * from,
extern_type const * end, size_t max) const
{
// The docs are a bit unclear about this method.
// It seems that we should calculate the actual length of the
// converted sequence, but that would not make sense, since
// once could just do the conversion directly.
// Therefore we just return the number of unconverted
// characters, since that is the best guess we can do.
#if 0
intern_type * to = new intern_type[max];
intern_type * to_end = to + max;
intern_type * to_next = to;
extern_type const * from_next = from;
do_in(state, from, end, from_next, to, to_end, to_next);
delete[] to;
return to_next - to;
#else
size_t const length = end - from;
return min(length, max);
#endif
}
virtual int do_max_length() const throw()
{
return lyx::max_encoded_bytes(encoding_);
}
private:
/// Do the actual conversion. The interface is equivalent to that of
/// iconv() (but const correct).
inline base::result do_iconv(iconv_t cd, char const ** from,
size_t * inbytesleft, char ** to, size_t * outbytesleft) const
{
char const * const to_start = *to;
size_t converted = iconv(cd, const_cast<char ICONV_CONST **>(from),
inbytesleft, to, outbytesleft);
if (converted == (size_t)(-1)) {
switch(errno) {
case 0:
// As strange as it may seem, this
// does happen on windows when parsing
// comments with accented chars in
// tex2lyx. See the following thread
// for details
// http://thread.gmane.org/gmane.editors.lyx.devel/117636
break;
case EINVAL:
case E2BIG:
return base::partial;
case EILSEQ:
default:
return base::error;
}
}
if (*to == to_start)
return base::noconv;
return base::ok;
}
iconv_t in_cd_;
iconv_t out_cd_;
/// The narrow encoding
string encoding_;
};
} // namespace
namespace lyx {
template<class Ios>
void setEncoding(Ios & ios, string const & encoding, ios_base::openmode mode)
{
// We must imbue the stream before openening the file
locale global;
locale locale(global, new iconv_codecvt_facet(encoding, mode));
ios.imbue(locale);
}
const char * iconv_codecvt_facet_exception::what() const throw()
{
return "iconv problem in iconv_codecvt_facet initialization";
}
ifdocstream::ifdocstream() : base()
{
setEncoding(*this, "UTF-8", in);
}
ifdocstream::ifdocstream(SetEnc const & enc) : base()
{
setEncoding(*this, enc.encoding, in);
}
ifdocstream::ifdocstream(const char* s, ios_base::openmode mode,
string const & encoding)
: base()
{
setEncoding(*this, encoding, in);
open(s, mode);
}
ofdocstream::ofdocstream(): base()
{
setEncoding(*this, "UTF-8", out);
}
ofdocstream::ofdocstream(SetEnc const & enc) : base()
{
setEncoding(*this, enc.encoding, out);
}
ofdocstream::ofdocstream(const char* s, ios_base::openmode mode,
string const & encoding)
: base()
{
setEncoding(*this, encoding, out);
open(s, mode);
}
void ofdocstream::reset(string const & encoding)
{
setEncoding(*this, encoding, out);
}
SetEnc setEncoding(string const & encoding)
{
return SetEnc(encoding);
}
odocstream & operator<<(odocstream & os, SetEnc e)
{
if (has_facet<iconv_codecvt_facet>(os.rdbuf()->getloc())) {
// This stream must be a file stream, since we never imbue
// any other stream with a locale having a iconv_codecvt_facet.
iconv_codecvt_facet const & facet =
use_facet<iconv_codecvt_facet>(os.rdbuf()->getloc());
// FIXME Changing the codecvt facet of an open file is allowed,
// but unsafe for facets that use internal state (see the thread
// "iostreams: Does imbue() need to be called before open()?"
// in comp.std.c++.
// Currently it seems to work with gcc and MSVC, but not with
// clang on OS X.
// Avoid imbueing with the same encoding again if possible.
if (facet.encoding() == e.encoding)
return os;
// Flush the stream so that all pending output is written
// with the old encoding.
os.flush();
locale locale(os.rdbuf()->getloc(),
new iconv_codecvt_facet(e.encoding, ios_base::out));
os.imbue(locale);
}
return os;
}
idocstream & operator<<(idocstream & is, SetEnc e)
{
if (has_facet<iconv_codecvt_facet>(is.rdbuf()->getloc())) {
// This stream must be a file stream, since we never imbue
// any other stream with a locale having a iconv_codecvt_facet.
iconv_codecvt_facet const & facet =
use_facet<iconv_codecvt_facet>(is.rdbuf()->getloc());
// FIXME Changing the codecvt facet of an open file is allowed,
// but unsafe for facets that use internal state (see the thread
// "iostreams: Does imbue() need to be called before open()?"
// in comp.std.c++.
// Currently it seems to work with gcc and MSVC, but not with
// clang on OS X.
// Avoid imbueing with the same encoding again if possible.
if (facet.encoding() == e.encoding)
return is;
locale locale(is.rdbuf()->getloc(),
new iconv_codecvt_facet(e.encoding, ios_base::in));
is.imbue(locale);
}
return is;
}
#if ! defined(USE_WCHAR_T)
odocstream & operator<<(odocstream & os, char c)
{
os.put(c);
return os;
}
#endif
} // namespace lyx
#if ! defined(USE_WCHAR_T) && defined(__GNUC__)
// We get undefined references to these virtual methods. This looks like
// a bug in gcc. The implementation here does not do anything useful, since
// it is overriden in iconv_codecvt_facet.
namespace std {
template<> codecvt<lyx::char_type, char, mbstate_t>::result
codecvt<lyx::char_type, char, mbstate_t>::do_out(
mbstate_t &, const lyx::char_type *, const lyx::char_type *,
const lyx::char_type *&, char *, char *, char *&) const
{
return error;
}
template<> codecvt<lyx::char_type, char, mbstate_t>::result
codecvt<lyx::char_type, char, mbstate_t>::do_unshift(
mbstate_t &, char *, char *, char *&) const
{
return error;
}
template<> codecvt<lyx::char_type, char, mbstate_t>::result
codecvt<lyx::char_type, char, mbstate_t>::do_in(
mbstate_t &, const char *, const char *, const char *&,
lyx::char_type *, lyx::char_type *, lyx::char_type *&) const
{
return error;
}
template<>
int codecvt<lyx::char_type, char, mbstate_t>::do_encoding() const throw()
{
return 0;
}
template<>
bool codecvt<lyx::char_type, char, mbstate_t>::do_always_noconv() const throw()
{
return true;
}
template<>
int codecvt<lyx::char_type, char, mbstate_t>::do_length(
mbstate_t &, const char *, const char *, size_t) const
{
return 1;
}
template<>
int codecvt<lyx::char_type, char, mbstate_t>::do_max_length() const throw()
{
return 4;
}
} // namespace std
#endif