ref: e1d94403fed4edc6607a1eebf7fda984d2c79cac
dir: /llt/utf8.c/
/*
Basic UTF-8 manipulation routines
by Jeff Bezanson
placed in the public domain Fall 2005
This code is designed to provide the utilities you need to manipulate
UTF-8 as an internal string encoding. These functions do not perform the
error checking normally needed when handling UTF-8 data, so if you happen
to be from the Unicode Consortium you will want to flay me alive.
I do this because error checking can be performed at the boundaries (I/O),
with these routines reserved for higher performance on data known to be
valid.
A UTF-8 validation routine is included.
*/
#include "llt.h"
static const uint32_t offsetsFromUTF8[6] = {
0x00000000UL, 0x00003080UL, 0x000E2080UL,
0x03C82080UL, 0xFA082080UL, 0x82082080UL
};
static const char trailingBytesForUTF8[256] = {
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5
};
// straight from musl
int
u8_iswprint(uint32_t c)
{
if(c < 0xff)
return ((c+1) & 0x7f) >= 0x21;
if(c < 0x2028 || c-0x202a < 0xd800-0x202a || c-0xe000 < 0xfff9-0xe000)
return 1;
return !(c-0xfffc > 0x10ffff-0xfffc || (c&0xfffe) == 0xfffe);
}
/* returns length of next utf-8 sequence */
size_t u8_seqlen(const char *s)
{
return trailingBytesForUTF8[(unsigned int)(uint8_t)s[0]] + 1;
}
/* returns the # of bytes needed to encode a certain character
0 means the character cannot (or should not) be encoded. */
size_t u8_charlen(uint32_t ch)
{
if (ch < 0x80)
return 1;
else if (ch < 0x800)
return 2;
else if (ch < 0x10000)
return 3;
else if (ch < 0x110000)
return 4;
return 0;
}
size_t u8_codingsize(uint32_t *wcstr, size_t n)
{
size_t i, c=0;
for(i=0; i < n; i++)
c += u8_charlen(wcstr[i]);
return c;
}
/* conversions without error checking
only works for valid UTF-8, i.e. no 5- or 6-byte sequences
srcsz = source size in bytes
sz = dest size in # of wide characters
returns # characters converted
if sz == srcsz+1 (i.e. 4*srcsz+4 bytes), there will always be enough space.
*/
size_t u8_toucs(uint32_t *dest, size_t sz, const char *src, size_t srcsz)
{
uint32_t ch;
const char *src_end = src + srcsz;
size_t nb;
size_t i=0;
if (sz == 0 || srcsz == 0)
return 0;
while (i < sz) {
if (!isutf(*src)) { // invalid sequence
dest[i++] = 0xFFFD;
src++;
if (src >= src_end) break;
continue;
}
nb = trailingBytesForUTF8[(uint8_t)*src];
if (src + nb >= src_end)
break;
ch = 0;
switch (nb) {
case 5: ch += (uint8_t)*src++; ch <<= 6; // fallthrough
case 4: ch += (uint8_t)*src++; ch <<= 6; // fallthrough
case 3: ch += (uint8_t)*src++; ch <<= 6; // fallthrough
case 2: ch += (uint8_t)*src++; ch <<= 6; // fallthrough
case 1: ch += (uint8_t)*src++; ch <<= 6; // fallthrough
case 0: ch += (uint8_t)*src++;
}
ch -= offsetsFromUTF8[nb];
dest[i++] = ch;
}
return i;
}
/* srcsz = number of source characters
sz = size of dest buffer in bytes
returns # bytes stored in dest
the destination string will never be bigger than the source string.
*/
size_t u8_toutf8(char *dest, size_t sz, const uint32_t *src, size_t srcsz)
{
uint32_t ch;
size_t i = 0;
char *dest0 = dest;
char *dest_end = dest + sz;
while (i < srcsz) {
ch = src[i];
if (ch < 0x80) {
if (dest >= dest_end)
break;
*dest++ = (char)ch;
}
else if (ch < 0x800) {
if (dest >= dest_end-1)
break;
*dest++ = (ch>>6) | 0xC0;
*dest++ = (ch & 0x3F) | 0x80;
}
else if (ch < 0x10000) {
if (dest >= dest_end-2)
break;
*dest++ = (ch>>12) | 0xE0;
*dest++ = ((ch>>6) & 0x3F) | 0x80;
*dest++ = (ch & 0x3F) | 0x80;
}
else if (ch < 0x110000) {
if (dest >= dest_end-3)
break;
*dest++ = (ch>>18) | 0xF0;
*dest++ = ((ch>>12) & 0x3F) | 0x80;
*dest++ = ((ch>>6) & 0x3F) | 0x80;
*dest++ = (ch & 0x3F) | 0x80;
}
i++;
}
return (dest-dest0);
}
size_t u8_wc_toutf8(char *dest, uint32_t ch)
{
if (ch < 0x80) {
dest[0] = (char)ch;
return 1;
}
if (ch < 0x800) {
dest[0] = (ch>>6) | 0xC0;
dest[1] = (ch & 0x3F) | 0x80;
return 2;
}
if (ch < 0x10000) {
dest[0] = (ch>>12) | 0xE0;
dest[1] = ((ch>>6) & 0x3F) | 0x80;
dest[2] = (ch & 0x3F) | 0x80;
return 3;
}
if (ch < 0x110000) {
dest[0] = (ch>>18) | 0xF0;
dest[1] = ((ch>>12) & 0x3F) | 0x80;
dest[2] = ((ch>>6) & 0x3F) | 0x80;
dest[3] = (ch & 0x3F) | 0x80;
return 4;
}
return 0;
}
/* charnum => byte offset */
size_t u8_offset(const char *s, size_t charnum)
{
size_t i=0;
while (charnum > 0) {
if (s[i++] & 0x80) {
(void)(isutf(s[++i]) || isutf(s[++i]) || ++i);
}
charnum--;
}
return i;
}
/* byte offset => charnum */
size_t u8_charnum(const char *s, size_t offset)
{
size_t charnum = 0, i=0;
while (i < offset) {
if (s[i++] & 0x80) {
(void)(isutf(s[++i]) || isutf(s[++i]) || ++i);
}
charnum++;
}
return charnum;
}
/* number of characters in NUL-terminated string */
size_t u8_strlen(const char *s)
{
size_t count = 0;
size_t i = 0, lasti;
while (1) {
lasti = i;
while (s[i] > 0)
i++;
count += (i-lasti);
if (s[i++]==0) break;
(void)(isutf(s[++i]) || isutf(s[++i]) || ++i);
count++;
}
return count;
}
size_t u8_strwidth(const char *s)
{
uint32_t ch;
size_t nb, tot=0;
int w;
signed char sc;
while ((sc = (signed char)*s) != 0) {
if (sc >= 0) {
s++;
if (sc) tot++;
}
else {
if (!isutf(sc)) { tot++; s++; continue; }
nb = trailingBytesForUTF8[(uint8_t)sc];
ch = 0;
switch (nb) {
case 5: ch += (uint8_t)*s++; ch <<= 6; // fallthrough
case 4: ch += (uint8_t)*s++; ch <<= 6; // fallthrough
case 3: ch += (uint8_t)*s++; ch <<= 6; // fallthrough
case 2: ch += (uint8_t)*s++; ch <<= 6; // fallthrough
case 1: ch += (uint8_t)*s++; ch <<= 6; // fallthrough
case 0: ch += (uint8_t)*s++;
}
ch -= offsetsFromUTF8[nb];
w = wcwidth(ch); // might return -1
if (w > 0) tot += w;
}
}
return tot;
}
/* reads the next utf-8 sequence out of a string, updating an index */
uint32_t u8_nextchar(const char *s, size_t *i)
{
uint32_t ch = 0;
size_t sz = 0;
do {
ch <<= 6;
ch += (uint8_t)s[(*i)];
sz++;
} while (s[*i] && (++(*i)) && !isutf(s[*i]));
ch -= offsetsFromUTF8[sz-1];
return ch;
}
/* next character without NUL character terminator */
uint32_t u8_nextmemchar(const char *s, size_t *i)
{
uint32_t ch = 0;
size_t sz = 0;
do {
ch <<= 6;
ch += (uint8_t)s[(*i)++];
sz++;
} while (!isutf(s[*i]));
ch -= offsetsFromUTF8[sz-1];
return ch;
}
void u8_inc(const char *s, size_t *i)
{
(void)(isutf(s[++(*i)]) || isutf(s[++(*i)]) || isutf(s[++(*i)]) || ++(*i));
}
void u8_dec(const char *s, size_t *i)
{
(void)(isutf(s[--(*i)]) || isutf(s[--(*i)]) || isutf(s[--(*i)]) || --(*i));
}
int octal_digit(char c)
{
return (c >= '0' && c <= '7');
}
int hex_digit(char c)
{
return ((c >= '0' && c <= '9') ||
(c >= 'A' && c <= 'F') ||
(c >= 'a' && c <= 'f'));
}
char read_escape_control_char(char c)
{
if (c == 'n')
return '\n';
else if (c == 't')
return '\t';
else if (c == 'r')
return '\r';
else if (c == 'e')
return '\e';
else if (c == 'b')
return '\b';
else if (c == 'f')
return '\f';
else if (c == 'v')
return '\v';
else if (c == 'a')
return '\a';
return c;
}
/* assumes that src points to the character after a backslash
returns number of input characters processed, 0 if error */
size_t u8_read_escape_sequence(const char *str, size_t ssz, uint32_t *dest)
{
assert(ssz > 0);
uint32_t ch;
char digs[10];
int dno=0, ndig;
size_t i=1;
char c0 = str[0];
if (octal_digit(c0)) {
i = 0;
do {
digs[dno++] = str[i++];
} while (i<ssz && octal_digit(str[i]) && dno<3);
digs[dno] = '\0';
ch = strtol(digs, nil, 8);
}
else if ((c0=='x' && (ndig=2)) ||
(c0=='u' && (ndig=4)) ||
(c0=='U' && (ndig=8))) {
while (i<ssz && hex_digit(str[i]) && dno<ndig) {
digs[dno++] = str[i++];
}
if (dno == 0) return 0;
digs[dno] = '\0';
ch = strtol(digs, nil, 16);
}
else {
ch = (uint32_t)read_escape_control_char(c0);
}
*dest = ch;
return i;
}
/* convert a string with literal \uxxxx or \Uxxxxxxxx characters to UTF-8
example: u8_unescape(mybuf, 256, "hello\\u220e")
note the double backslash is needed if called on a C string literal */
size_t u8_unescape(char *buf, size_t sz, const char *src)
{
size_t c=0, amt;
uint32_t ch;
char temp[4];
while (*src && c < sz) {
if (*src == '\\') {
src++;
amt = u8_read_escape_sequence(src, 1000, &ch);
}
else {
ch = (uint32_t)*src;
amt = 1;
}
src += amt;
amt = u8_wc_toutf8(temp, ch);
if (amt > sz-c)
break;
memmove(&buf[c], temp, amt);
c += amt;
}
if (c < sz)
buf[c] = '\0';
return c;
}
static inline int buf_put2c(char *buf, const char *src)
{
buf[0] = src[0];
buf[1] = src[1];
buf[2] = '\0';
return 2;
}
int u8_escape_wchar(char *buf, size_t sz, uint32_t ch)
{
assert(sz > 2);
if (ch >= 0x20 && ch < 0x7f) {
buf[0] = ch;
buf[1] = '\0';
return 1;
}
if (ch > 0xffff)
return snprintf(buf, sz, "\\U%.8x", ch);
if (ch >= 0x80)
return snprintf(buf, sz, "\\u%04x", ch);
switch (ch) {
case '\n': return buf_put2c(buf, "\\n");
case '\t': return buf_put2c(buf, "\\t");
case '\r': return buf_put2c(buf, "\\r");
case '\e': return buf_put2c(buf, "\\e");
case '\b': return buf_put2c(buf, "\\b");
case '\f': return buf_put2c(buf, "\\f");
case '\v': return buf_put2c(buf, "\\v");
case '\a': return buf_put2c(buf, "\\a");
case '\\': return buf_put2c(buf, "\\\\");
}
return snprintf(buf, sz, "\\x%02x", ch);
}
size_t u8_escape(char *buf, size_t sz, const char *src, size_t *pi, size_t end,
int escape_quotes, int ascii)
{
size_t i = *pi, i0;
uint32_t ch;
char *start = buf;
char *blim = start + sz-11;
assert(sz > 11);
while (i<end && buf<blim) {
// sz-11: leaves room for longest escape sequence
if (escape_quotes && src[i] == '"') {
buf += buf_put2c(buf, "\\\"");
i++;
}
else if (src[i] == '\\') {
buf += buf_put2c(buf, "\\\\");
i++;
}
else {
i0 = i;
ch = u8_nextmemchar(src, &i);
if (ascii || !u8_iswprint(ch)) {
buf += u8_escape_wchar(buf, sz - (buf-start), ch);
}
else {
i = i0;
do {
*buf++ = src[i++];
} while (!isutf(src[i]));
}
}
}
*buf++ = '\0';
*pi = i;
return (buf-start);
}
char *u8_strchr(const char *s, uint32_t ch, size_t *charn)
{
size_t i = 0, lasti=0;
uint32_t c;
*charn = 0;
while (s[i]) {
c = u8_nextchar(s, &i);
if (c == ch) {
/* it's const for us, but not necessarily the caller */
return (char*)&s[lasti];
}
lasti = i;
(*charn)++;
}
return nil;
}
char *u8_memchr(const char *s, uint32_t ch, size_t sz, size_t *charn)
{
size_t i = 0, lasti=0;
uint32_t c;
int csz;
*charn = 0;
while (i < sz) {
c = csz = 0;
do {
c <<= 6;
c += (uint8_t)s[i++];
csz++;
} while (i < sz && !isutf(s[i]));
c -= offsetsFromUTF8[csz-1];
if (c == ch) {
return (char*)&s[lasti];
}
lasti = i;
(*charn)++;
}
return nil;
}
char *u8_memrchr(const char *s, uint32_t ch, size_t sz)
{
size_t i = sz-1, tempi=0;
uint32_t c;
if (sz == 0) return nil;
while (i && !isutf(s[i])) i--;
while (1) {
tempi = i;
c = u8_nextmemchar(s, &tempi);
if (c == ch) {
return (char*)&s[i];
}
if (i == 0)
break;
tempi = i;
u8_dec(s, &i);
if (i > tempi)
break;
}
return nil;
}
size_t u8_vprintf(const char *fmt, va_list ap)
{
size_t cnt, sz, nc, needfree=0;
char *buf, tmp[512];
uint32_t *wcs;
sz = 512;
buf = tmp;
cnt = vsnprintf(buf, sz, fmt, ap);
if ((ssize_t)cnt < 0)
return 0;
if (cnt >= sz) {
buf = (char*)malloc(cnt + 1);
needfree = 1;
vsnprintf(buf, cnt+1, fmt, ap);
}
wcs = (uint32_t*)malloc((cnt+1) * sizeof(uint32_t));
nc = u8_toucs(wcs, cnt+1, buf, cnt);
wcs[nc] = 0;
#if defined(__plan9__)
print("%S", (Rune*)wcs);
#else
printf("%ls", (wchar_t*)wcs);
#endif
free(wcs);
if (needfree) free(buf);
return nc;
}
size_t u8_printf(const char *fmt, ...)
{
size_t cnt;
va_list args;
va_start(args, fmt);
cnt = u8_vprintf(fmt, args);
va_end(args);
return cnt;
}
/* based on the valid_utf8 routine from the PCRE library by Philip Hazel
length is in bytes, since without knowing whether the string is valid
it's hard to know how many characters there are! */
int u8_isvalid(const char *str, int length)
{
const uint8_t *p, *pend = (uint8_t*)str + length;
uint8_t c;
int ab;
for (p = (uint8_t*)str; p < pend; p++) {
c = *p;
if (c < 128)
continue;
if ((c & 0xc0) != 0xc0)
return 0;
ab = trailingBytesForUTF8[c];
if (length < ab)
return 0;
length -= ab;
p++;
/* Check top bits in the second byte */
if ((*p & 0xc0) != 0x80)
return 0;
/* Check for overlong sequences for each different length */
switch (ab) {
/* Check for xx00 000x */
case 1:
if ((c & 0x3e) == 0) return 0;
continue; /* We know there aren't any more bytes to check */
/* Check for 1110 0000, xx0x xxxx */
case 2:
if (c == 0xe0 && (*p & 0x20) == 0) return 0;
break;
/* Check for 1111 0000, xx00 xxxx */
case 3:
if (c == 0xf0 && (*p & 0x30) == 0) return 0;
break;
/* Check for 1111 1000, xx00 0xxx */
case 4:
if (c == 0xf8 && (*p & 0x38) == 0) return 0;
break;
/* Check for leading 0xfe or 0xff,
and then for 1111 1100, xx00 00xx */
case 5:
if (c == 0xfe || c == 0xff ||
(c == 0xfc && (*p & 0x3c) == 0)) return 0;
break;
}
/* Check for valid bytes after the 2nd, if any; all must start 10 */
while (--ab > 0) {
if ((*(++p) & 0xc0) != 0x80) return 0;
}
}
return 1;
}
int u8_reverse(char *dest, char * src, size_t len)
{
size_t si=0, di=len;
uint8_t c;
dest[di] = '\0';
while (si < len) {
c = (uint8_t)src[si];
if ((~c) & 0x80) {
di--;
dest[di] = c;
si++;
}
else {
switch (c>>4) {
case 0xC:
case 0xD:
di -= 2;
*((int16_t*)&dest[di]) = *((int16_t*)&src[si]);
si += 2;
break;
case 0xE:
di -= 3;
dest[di] = src[si];
*((int16_t*)&dest[di+1]) = *((int16_t*)&src[si+1]);
si += 3;
break;
case 0xF:
di -= 4;
*((int32_t*)&dest[di]) = *((int32_t*)&src[si]);
si += 4;
break;
default:
return 1;
}
}
}
return 0;
}