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forked from GitHub/gf-core
Files
gf-core/src/runtime/c/gu/utf8.c
2015-05-06 15:51:12 +00:00

177 lines
3.4 KiB
C

#include <gu/assert.h>
#include <gu/utf8.h>
GuUCS
gu_utf8_decode(const uint8_t** src_inout)
{
const uint8_t* src = *src_inout;
uint8_t c = src[0];
if (c < 0x80) {
*src_inout = src + 1;
return (GuUCS) c;
}
size_t len = (c < 0xe0 ? 1 :
c < 0xf0 ? 2 :
c < 0xf8 ? 3 :
c < 0xfc ? 4 :
5
);
uint64_t mask = 0x0103070F1f7f;
uint32_t u = c & (mask >> (len * 8));
for (size_t i = 1; i <= len; i++) {
c = src[i];
u = u << 6 | (c & 0x3f);
}
*src_inout = &src[len + 1];
return (GuUCS) u;
}
GuUCS
gu_in_utf8_(GuIn* in, GuExn* err)
{
uint8_t c = gu_in_u8(in, err);
if (!gu_ok(err)) {
return 0;
}
if (c < 0x80) {
return c;
}
if (c < 0xc2) {
goto fail;
}
int len = (c < 0xe0 ? 1 :
c < 0xf0 ? 2 :
c < 0xf8 ? 3 :
c < 0xfc ? 4 :
5
);
uint64_t mask = 0x0103070F1f7f;
uint32_t u = c & (mask >> (len * 8));
uint8_t buf[5];
// If reading the extra bytes causes EOF, it is an encoding
// error, not a legitimate end of character stream.
gu_in_bytes(in, buf, len, err);
if (gu_exn_caught(err, GuEOF)) {
gu_exn_clear(err);
goto fail;
}
if (!gu_ok(err)) {
return 0;
}
for (int i = 0; i < len; i++) {
c = buf[i];
if ((c & 0xc0) != 0x80) {
goto fail;
}
u = u << 6 | (c & 0x3f);
}
GuUCS ucs = (GuUCS) u;
if (!gu_ucs_valid(ucs)) {
goto fail;
}
return ucs;
fail:
gu_raise(err, GuUCSExn);
return 0;
}
extern inline GuUCS
gu_in_utf8(GuIn* in, GuExn* err);
void
gu_in_utf8_buf(uint8_t** buf, GuIn* in, GuExn* err)
{
uint8_t* p = *buf;
uint8_t c = gu_in_u8(in, err);
if (!gu_ok(err)) {
return;
}
*(p++) = c;
if (c < 0x80) {
*buf = p;
return;
}
if (c < 0xc2) {
goto fail;
}
int len = (c < 0xe0 ? 1 :
c < 0xf0 ? 2 :
c < 0xf8 ? 3 :
c < 0xfc ? 4 :
5
);
// If reading the extra bytes causes EOF, it is an encoding
// error, not a legitimate end of character stream.
gu_in_bytes(in, p, len, err);
if (gu_exn_caught(err, GuEOF)) {
gu_exn_clear(err);
goto fail;
}
if (!gu_ok(err)) {
return;
}
*buf = p+len;
return;
fail:
gu_raise(err, GuUCSExn);
return;
}
void
gu_utf8_encode(GuUCS ucs, uint8_t** buf)
{
gu_require(gu_ucs_valid(ucs));
uint8_t* p = *buf;
if (ucs < 0x80) {
p[0] = (uint8_t) ucs;
*buf = p+1;
} else if (ucs < 0x800) {
p[0] = 0xc0 | (ucs >> 6);
p[1] = 0x80 | (ucs & 0x3f);
*buf = p+2;
} else if (ucs < 0x10000) {
p[0] = 0xe0 | (ucs >> 12);
p[1] = 0x80 | ((ucs >> 6) & 0x3f);
p[2] = 0x80 | (ucs & 0x3f);
*buf = p+3;
} else if (ucs < 0x200000) {
p[0] = 0xf0 | (ucs >> 18);
p[1] = 0x80 | ((ucs >> 12) & 0x3f);
p[2] = 0x80 | ((ucs >> 6) & 0x3f);
p[3] = 0x80 | (ucs & 0x3f);
*buf = p+4;
} else if (ucs < 0x4000000) {
p[0] = 0xf8 | (ucs >> 24);
p[1] = 0x80 | ((ucs >> 18) & 0x3f);
p[2] = 0x80 | ((ucs >> 12) & 0x3f);
p[3] = 0x80 | ((ucs >> 6) & 0x3f);
p[4] = 0x80 | (ucs & 0x3f);
*buf = p+5;
} else {
p[0] = 0xfc | (ucs >> 30);
p[1] = 0x80 | ((ucs >> 24) & 0x3f);
p[2] = 0x80 | ((ucs >> 18) & 0x3f);
p[3] = 0x80 | ((ucs >> 12) & 0x3f);
p[4] = 0x80 | ((ucs >> 6) & 0x3f);
p[5] = 0x80 | (ucs & 0x3f);
*buf = p+6;
}
}
void
gu_out_utf8_(GuUCS ucs, GuOut* out, GuExn* err)
{
uint8_t buf[6];
uint8_t* p = buf;
gu_utf8_encode(ucs, &p);
gu_out_bytes(out, buf, p-buf, err);
}
extern inline void
gu_out_utf8(GuUCS ucs, GuOut* out, GuExn* err);