long webc_decode_string (WebcCharDecodeStream *stream)
{
int n = stream->charset;
n = EBSCLIP(n, 0, WEBC_NUM_CHARSETS-1);
if (decode_table[n] != 0)
{
return (decode_table[n](stream));
}
return (decode_ascii(stream));
}
/* Decode a byte string from the locale encoding.
Use the strict error handler if 'surrogateescape' is zero. Use the
surrogateescape error handler if 'surrogateescape' is non-zero: undecodable
bytes are decoded as characters in range U+DC80..U+DCFF. If a byte sequence
can be decoded as a surrogate character, escape the bytes using the
surrogateescape error handler instead of decoding them.
On success, return 0 and write the newly allocated wide character string into
*wstr (use PyMem_RawFree() to free the memory). If wlen is not NULL, write
the number of wide characters excluding the null character into *wlen.
On memory allocation failure, return -1.
On decoding error, return -2. If wlen is not NULL, write the start of
invalid byte sequence in the input string into *wlen. If reason is not NULL,
write the decoding error message into *reason.
Use the Py_EncodeLocaleEx() function to encode the character string back to
a byte string. */
int
_Py_DecodeLocaleEx(const char* arg, wchar_t **wstr, size_t *wlen,
const char **reason,
int current_locale, int surrogateescape)
{
if (current_locale) {
#ifdef __ANDROID__
return _Py_DecodeUTF8Ex(arg, strlen(arg), wstr, wlen, reason,
surrogateescape);
#else
return decode_current_locale(arg, wstr, wlen, reason, surrogateescape);
#endif
}
#if defined(__APPLE__) || defined(__ANDROID__)
return _Py_DecodeUTF8Ex(arg, strlen(arg), wstr, wlen, reason,
surrogateescape);
#else
if (Py_UTF8Mode == 1) {
return _Py_DecodeUTF8Ex(arg, strlen(arg), wstr, wlen, reason,
surrogateescape);
}
#ifdef USE_FORCE_ASCII
if (force_ascii == -1) {
force_ascii = check_force_ascii();
}
if (force_ascii) {
/* force ASCII encoding to workaround mbstowcs() issue */
return decode_ascii(arg, wstr, wlen, reason, surrogateescape);
}
#endif
return decode_current_locale(arg, wstr, wlen, reason, surrogateescape);
#endif /* __APPLE__ or __ANDROID__ */
}
static int
decode_current_locale(const char* arg, wchar_t **wstr, size_t *wlen,
const char **reason, int surrogateescape)
{
wchar_t *res;
size_t argsize;
size_t count;
#ifdef HAVE_MBRTOWC
unsigned char *in;
wchar_t *out;
mbstate_t mbs;
#endif
#ifdef HAVE_BROKEN_MBSTOWCS
/* Some platforms have a broken implementation of
* mbstowcs which does not count the characters that
* would result from conversion. Use an upper bound.
*/
argsize = strlen(arg);
#else
argsize = mbstowcs(NULL, arg, 0);
#endif
if (argsize != (size_t)-1) {
if (argsize > PY_SSIZE_T_MAX / sizeof(wchar_t) - 1) {
return -1;
}
res = (wchar_t *)PyMem_RawMalloc((argsize + 1) * sizeof(wchar_t));
if (!res) {
return -1;
}
count = mbstowcs(res, arg, argsize + 1);
if (count != (size_t)-1) {
wchar_t *tmp;
/* Only use the result if it contains no
surrogate characters. */
for (tmp = res; *tmp != 0 &&
!Py_UNICODE_IS_SURROGATE(*tmp); tmp++)
;
if (*tmp == 0) {
if (wlen != NULL) {
*wlen = count;
}
*wstr = res;
return 0;
}
}
PyMem_RawFree(res);
}
/* Conversion failed. Fall back to escaping with surrogateescape. */
#ifdef HAVE_MBRTOWC
/* Try conversion with mbrtwoc (C99), and escape non-decodable bytes. */
/* Overallocate; as multi-byte characters are in the argument, the
actual output could use less memory. */
argsize = strlen(arg) + 1;
if (argsize > PY_SSIZE_T_MAX / sizeof(wchar_t)) {
return -1;
}
res = (wchar_t*)PyMem_RawMalloc(argsize * sizeof(wchar_t));
if (!res) {
return -1;
}
in = (unsigned char*)arg;
out = res;
memset(&mbs, 0, sizeof mbs);
while (argsize) {
size_t converted = mbrtowc(out, (char*)in, argsize, &mbs);
if (converted == 0) {
/* Reached end of string; null char stored. */
break;
}
if (converted == (size_t)-2) {
/* Incomplete character. This should never happen,
since we provide everything that we have -
unless there is a bug in the C library, or I
misunderstood how mbrtowc works. */
goto decode_error;
}
if (converted == (size_t)-1) {
if (!surrogateescape) {
goto decode_error;
}
/* Conversion error. Escape as UTF-8b, and start over
in the initial shift state. */
*out++ = 0xdc00 + *in++;
argsize--;
memset(&mbs, 0, sizeof mbs);
continue;
}
if (Py_UNICODE_IS_SURROGATE(*out)) {
if (!surrogateescape) {
goto decode_error;
}
/* Surrogate character. Escape the original
byte sequence with surrogateescape. */
argsize -= converted;
while (converted--) {
*out++ = 0xdc00 + *in++;
}
continue;
}
/* successfully converted some bytes */
in += converted;
argsize -= converted;
out++;
}
if (wlen != NULL) {
*wlen = out - res;
}
*wstr = res;
return 0;
decode_error:
PyMem_RawFree(res);
if (wlen) {
*wlen = in - (unsigned char*)arg;
}
if (reason) {
*reason = "decoding error";
}
return -2;
#else /* HAVE_MBRTOWC */
/* Cannot use C locale for escaping; manually escape as if charset
is ASCII (i.e. escape all bytes > 128. This will still roundtrip
correctly in the locale's charset, which must be an ASCII superset. */
return decode_ascii(arg, wstr, wlen, reason, surrogateescape);
#endif /* HAVE_MBRTOWC */
}
