size_t c16rtomb(char* s, char16_t c16, mbstate_t* ps) {
static mbstate_t __private_state;
mbstate_t* state = (ps == NULL) ? &__private_state : ps;
if (mbsinit(state)) {
if (is_high_surrogate(c16)) {
char32_t c32 = (c16 & ~0xd800) << 10;
mbstate_set_byte(state, 3, (c32 & 0xff0000) >> 16);
mbstate_set_byte(state, 2, (c32 & 0x00ff00) >> 8);
return 0;
} else if (is_low_surrogate(c16)) {
return reset_and_return_illegal(EINVAL, state);
} else {
return c32rtomb(s, static_cast<char32_t>(c16), state);
}
} else {
size_t mbrtowc(wchar_t* pwc, const char* s, size_t n, mbstate_t* ps) {
static mbstate_t __private_state;
mbstate_t* state = (ps == NULL) ? &__private_state : ps;
// We should never get to a state which has all 4 bytes of the sequence set.
// Full state verification is done when decoding the sequence (after we have
// all the bytes).
if (mbstate_get_byte(state, 3) != 0) {
return reset_and_return_illegal(EINVAL, state);
}
if (s == NULL) {
s = "";
n = 1;
pwc = NULL;
}
if (n == 0) {
return 0;
}
uint8_t ch;
if (mbsinit(state) && (((ch = static_cast<uint8_t>(*s)) & ~0x7f) == 0)) {
// Fast path for plain ASCII characters.
if (pwc != NULL) {
*pwc = ch;
}
return (ch != '\0' ? 1 : 0);
}
// Determine the number of octets that make up this character
// from the first octet, and a mask that extracts the
// interesting bits of the first octet. We already know
// the character is at least two bytes long.
size_t length;
int mask;
// We also specify a lower bound for the character code to
// detect redundant, non-"shortest form" encodings. For
// example, the sequence C0 80 is _not_ a legal representation
// of the null character. This enforces a 1-to-1 mapping
// between character codes and their multibyte representations.
wchar_t lower_bound;
// The first byte in the state (if any) tells the length.
size_t bytes_so_far = mbstate_bytes_so_far(state);
ch = bytes_so_far > 0 ? mbstate_get_byte(state, 0) : static_cast<uint8_t>(*s);
if ((ch & 0x80) == 0) {
mask = 0x7f;
length = 1;
lower_bound = 0;
} else if ((ch & 0xe0) == 0xc0) {
mask = 0x1f;
length = 2;
lower_bound = 0x80;
} else if ((ch & 0xf0) == 0xe0) {
mask = 0x0f;
length = 3;
lower_bound = 0x800;
} else if ((ch & 0xf8) == 0xf0) {
mask = 0x07;
length = 4;
lower_bound = 0x10000;
} else {
// Malformed input; input is not UTF-8. See RFC 3629.
return reset_and_return_illegal(EILSEQ, state);
}
// Fill in the state.
size_t bytes_wanted = length - bytes_so_far;
size_t i;
for (i = 0; i < MIN(bytes_wanted, n); i++) {
if (!mbsinit(state) && ((*s & 0xc0) != 0x80)) {
// Malformed input; bad characters in the middle of a character.
return reset_and_return_illegal(EILSEQ, state);
}
mbstate_set_byte(state, bytes_so_far + i, *s++);
}
if (i < bytes_wanted) {
return ERR_INCOMPLETE_SEQUENCE;
}
// Decode the octet sequence representing the character in chunks
// of 6 bits, most significant first.
wchar_t wch = mbstate_get_byte(state, 0) & mask;
for (i = 1; i < length; i++) {
wch <<= 6;
wch |= mbstate_get_byte(state, i) & 0x3f;
}
if (wch < lower_bound) {
// Malformed input; redundant encoding.
return reset_and_return_illegal(EILSEQ, state);
}
if ((wch >= 0xd800 && wch <= 0xdfff) || wch == 0xfffe || wch == 0xffff) {
// Malformed input; invalid code points.
return reset_and_return_illegal(EILSEQ, state);
}
if (pwc != NULL) {
*pwc = wch;
}
return reset_and_return(wch == L'\0' ? 0 : bytes_wanted, state);
}
size_t wcsnrtombs(char* dst, const wchar_t** src, size_t nwc, size_t len, mbstate_t* ps) {
static mbstate_t __private_state;
mbstate_t* state = (ps == NULL) ? &__private_state : ps;
if (!mbsinit(state)) {
return reset_and_return_illegal(EILSEQ, state);
}
char buf[MB_LEN_MAX];
size_t i, o, r;
if (dst == NULL) {
for (i = o = 0; i < nwc; i++, o += r) {
wchar_t wc = (*src)[i];
if (static_cast<uint32_t>(wc) < 0x80) {
// Fast path for plain ASCII characters.
if (wc == 0) {
return o;
}
r = 1;
} else {
r = wcrtomb(buf, wc, state);
if (r == ERR_ILLEGAL_SEQUENCE) {
return r;
}
}
}
return o;
}
for (i = o = 0; i < nwc && o < len; i++, o += r) {
wchar_t wc = (*src)[i];
if (static_cast<uint32_t>(wc) < 0x80) {
// Fast path for plain ASCII characters.
dst[o] = wc;
if (wc == 0) {
*src = NULL;
return o;
}
r = 1;
} else if (len - o >= sizeof(buf)) {
// Enough space to translate in-place.
r = wcrtomb(dst + o, wc, state);
if (r == ERR_ILLEGAL_SEQUENCE) {
*src += i;
return r;
}
} else {
// May not be enough space; use temp buffer.
r = wcrtomb(buf, wc, state);
if (r == ERR_ILLEGAL_SEQUENCE) {
*src += i;
return r;
}
if (r > len - o) {
break;
}
memcpy(dst + o, buf, r);
}
}
*src += i;
return o;
}
size_t wcrtomb(char* s, wchar_t wc, mbstate_t* ps) {
static mbstate_t __private_state;
mbstate_t* state = (ps == NULL) ? &__private_state : ps;
if (s == NULL) {
// Equivalent to wcrtomb(buf, L'\0', ps).
return reset_and_return(1, state);
}
// POSIX states that if wc is a null wide character, a null byte shall be
// stored, preceded by any shift sequence needed to restore the initial shift
// state. Since shift states are not supported, only the null byte is stored.
if (wc == L'\0') {
*s = '\0';
reset_and_return(1, state);
}
if (!mbsinit(state)) {
return reset_and_return_illegal(EILSEQ, state);
}
if ((wc & ~0x7f) == 0) {
// Fast path for plain ASCII characters.
*s = wc;
return 1;
}
// Determine the number of octets needed to represent this character.
// We always output the shortest sequence possible. Also specify the
// first few bits of the first octet, which contains the information
// about the sequence length.
uint8_t lead;
size_t length;
if ((wc & ~0x7f) == 0) {
lead = 0;
length = 1;
} else if ((wc & ~0x7ff) == 0) {
lead = 0xc0;
length = 2;
} else if ((wc & ~0xffff) == 0) {
lead = 0xe0;
length = 3;
} else if ((wc & ~0x1fffff) == 0) {
lead = 0xf0;
length = 4;
} else {
errno = EILSEQ;
return ERR_ILLEGAL_SEQUENCE;
}
// Output the octets representing the character in chunks
// of 6 bits, least significant last. The first octet is
// a special case because it contains the sequence length
// information.
for (size_t i = length - 1; i > 0; i--) {
s[i] = (wc & 0x3f) | 0x80;
wc >>= 6;
}
*s = (wc & 0xff) | lead;
return length;
}
size_t mbsnrtowcs(wchar_t* dst, const char** src, size_t nmc, size_t len, mbstate_t* ps) {
static mbstate_t __private_state;
mbstate_t* state = (ps == NULL) ? &__private_state : ps;
size_t i, o, r;
if (dst == NULL) {
/*
* The fast path in the loop below is not safe if an ASCII
* character appears as anything but the first byte of a
* multibyte sequence. Check now to avoid doing it in the loop.
*/
if ((nmc > 0) && (mbstate_bytes_so_far(state) > 0)
&& (static_cast<uint8_t>((*src)[0]) < 0x80)) {
return reset_and_return_illegal(EILSEQ, state);
}
for (i = o = 0; i < nmc; i += r, o++) {
if (static_cast<uint8_t>((*src)[i]) < 0x80) {
// Fast path for plain ASCII characters.
if ((*src)[i] == '\0') {
return reset_and_return(o, state);
}
r = 1;
} else {
r = mbrtowc(NULL, *src + i, nmc - i, state);
if (r == ERR_ILLEGAL_SEQUENCE) {
return reset_and_return_illegal(EILSEQ, state);
}
if (r == ERR_INCOMPLETE_SEQUENCE) {
return reset_and_return_illegal(EILSEQ, state);
}
if (r == 0) {
return reset_and_return(o, state);
}
}
}
return reset_and_return(o, state);
}
/*
* The fast path in the loop below is not safe if an ASCII
* character appears as anything but the first byte of a
* multibyte sequence. Check now to avoid doing it in the loop.
*/
if ((nmc > 0) && (mbstate_bytes_so_far(state) > 0)
&& (static_cast<uint8_t>((*src)[0]) < 0x80)) {
return reset_and_return_illegal(EILSEQ, state);
}
for (i = o = 0; i < nmc && o < len; i += r, o++) {
if (static_cast<uint8_t>((*src)[i]) < 0x80) {
// Fast path for plain ASCII characters.
dst[o] = (*src)[i];
if ((*src)[i] == '\0') {
*src = NULL;
return reset_and_return_illegal(EILSEQ, state);
}
r = 1;
} else {
r = mbrtowc(dst + o, *src + i, nmc - i, state);
if (r == ERR_ILLEGAL_SEQUENCE) {
*src += i;
return reset_and_return_illegal(EILSEQ, state);
}
if (r == ERR_INCOMPLETE_SEQUENCE) {
*src += nmc;
return reset_and_return(EILSEQ, state);
}
if (r == 0) {
*src = NULL;
return reset_and_return(o, state);
}
}
}
*src += i;
return reset_and_return(o, state);
}
