static UINTVAL
utf8_scan(PARROT_INTERP, ARGIN(const STRING *src))
{
ASSERT_ARGS(utf8_scan)
const utf8_t *u8ptr = (const utf8_t *)src->strstart;
const utf8_t *u8end = (const utf8_t *)(src->strstart + src->bufused);
UINTVAL characters = 0;
while (u8ptr < u8end) {
UINTVAL c = *u8ptr;
if (UTF8_IS_START(c)) {
size_t len = UTF8SKIP(u8ptr);
size_t count;
if (u8ptr + len > u8end)
Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_MALFORMED_UTF8,
"Unaligned end in UTF-8 string\n");
/* Check for overlong forms */
if (UTF8_IS_OVERLONG(c, u8ptr[1]))
Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_MALFORMED_UTF8,
"Overlong form in UTF-8 string\n");
c &= UTF8_START_MASK(len);
for (count = 1; count < len; ++count) {
++u8ptr;
if (!UTF8_IS_CONTINUATION(*u8ptr))
Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_MALFORMED_UTF8,
"Malformed UTF-8 string\n");
c = UTF8_ACCUMULATE(c, *u8ptr);
}
if (UNICODE_IS_INVALID(c))
Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_INVALID_CHARACTER,
"Invalid character in UTF-8 string\n");
}
else if (!UNICODE_IS_INVARIANT(c)) {
Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_MALFORMED_UTF8,
"Malformed UTF-8 string\n");
}
++u8ptr;
++characters;
}
return characters;
}
EXTERN bool
probably_utf8_chunk(pTHX_ char *s, STRLEN len)
{
char *e = s + len;
STRLEN clen;
/* ignore partial utf8 char at end of buffer */
while (s < e && UTF8_IS_CONTINUATION((U8)*(e - 1)))
e--;
if (s < e && UTF8_IS_START((U8)*(e - 1)))
e--;
clen = len - (e - s);
if (clen && UTF8SKIP(e) == clen) {
/* all promised continuation bytes are present */
e = s + len;
}
if (!has_hibit(s, e))
return 0;
return is_utf8_string((U8*)s, e - s);
}
