lyx_mirror/src/support/docstream.cpp
Enrico Forestieri 07c0a6e496 Fix bug http://bugzilla.lyx.org/show_bug.cgi?id=5489 and at the same time
properly fix bugs 5216 and 5280. The best thing to do would be recognizing
at configure time a buggy iconv and #defining WORKAROUND_ICONV_BUG in
config.h, but I don't know how that could be done.


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@27618 a592a061-630c-0410-9148-cb99ea01b6c8
2008-11-18 10:40:22 +00:00

478 lines
13 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/unicode.h"
#include <cerrno>
#include <cstdio>
#include <cstring>
#include <iconv.h>
#include <locale>
using namespace std;
using lyx::ucs4_codeset;
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);
}
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, it gets truncated (see bugs 5216,
// 5280, and also 5489). As a workaround, we append a null
// char and then remove it from output after the conversion.
intern_type * from_new = 0;
if (*(from_end - 1) >= 0x80) {
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;
}
#endif
size_t inbytesleft = (from_end - from) * sizeof(intern_type);
size_t outbytesleft = (to_end - to) * sizeof(extern_type);
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 null char that we inserted at the end
// of the input buffer in order to circumvent an iconv bug.
if (from_new)
--to_next;
#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 c = *i;
fprintf(stderr, " 0x%04x", c);
}
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 c =
*reinterpret_cast<unsigned char const *>(i);
fprintf(stderr, " 0x%02x", c);
}
fputc('\n', stderr);
fflush(stderr);
}
#if WORKAROUND_ICONV_BUG
delete[] from_new;
#endif
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 c =
*reinterpret_cast<unsigned char const *>(i);
fprintf(stderr, " 0x%02x", c);
}
fputs("\nConverted output:", stderr);
for (intern_type const * i = to; i < to_next; ++i) {
unsigned int const c = *i;
fprintf(stderr, " 0x%02x", c);
}
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()
{
// FIXME: this information should be transferred to lib/encodings
// UTF8 uses at most 4 bytes to represent one UCS4 code point
// (see RFC 3629). RFC 2279 specifies 6 bytes, but that
// information is outdated, and RFC 2279 has been superseded by
// RFC 3629.
// The CJK encodings use (different) multibyte representation as well.
// All other encodings encode one UCS4 code point in one byte
// (and can therefore only encode a subset of UCS4)
// Note that BIG5 and SJIS do not work with LaTeX (see lib/encodings).
// Furthermore, all encodings that use shifting (like SJIS) do not work with
// iconv_codecvt_facet.
if (encoding_ == "UTF-8" ||
encoding_ == "GB" ||
encoding_ == "EUC-TW")
return 4;
else if (encoding_ == "EUC-JP" ||
encoding_ == "ISO-2022-JP")
return 3;
else if (encoding_ == "BIG5" ||
encoding_ == "EUC-KR" ||
encoding_ == "EUC-CN" ||
encoding_ == "SJIS" ||
encoding_ == "GBK")
return 2;
else
return 1;
}
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 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 anon
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(string const & encoding) : base()
{
setEncoding(*this, 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(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.
// 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));
// FIXME Does changing the codecvt facet of an open file
// stream always work? It does with gcc 4.1, but I have read
// somewhere that it does not with MSVC.
// What does the standard say?
os.imbue(locale);
}
return os;
}
//CHECKME: I just copied the code above, and have no idea whether it
//is correct... (JMarc)
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.
// Flush the stream so that all pending output is written
// with the old encoding.
//is.flush();
locale locale(is.rdbuf()->getloc(),
new iconv_codecvt_facet(e.encoding, ios_base::in));
// FIXME Does changing the codecvt facet of an open file
// stream always work? It does with gcc 4.1, but I have read
// somewhere that it does not with MSVC.
// What does the standard say?
is.imbue(locale);
}
return is;
}
#if ! defined(USE_WCHAR_T)
odocstream & operator<<(odocstream & os, char c)
{
os.put(c);
return os;
}
#endif
}
#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;
}
#if __GNUC__ == 3 && __GNUC_MINOR__ < 4
template<>
int codecvt<lyx::char_type, char, mbstate_t>::do_length(
mbstate_t const &, const char *, const char *, size_t) const
{
return 1;
}
#else
template<>
int codecvt<lyx::char_type, char, mbstate_t>::do_length(
mbstate_t &, const char *, const char *, size_t) const
{
return 1;
}
#endif
template<>
int codecvt<lyx::char_type, char, mbstate_t>::do_max_length() const throw()
{
return 4;
}
} // namespace std
#endif