nasm/strfunc.c

171 lines
3.2 KiB
C
Raw Normal View History

/*
* strfunc.c
*
* String transformation functions
*/
#include "nasmlib.h"
#include "nasm.h"
/*
* Convert a string in UTF-8 format to UTF-16LE
*/
static size_t utf8_to_16le(uint8_t *str, size_t len, char *op)
{
#define EMIT(x) do { if (op) { WRITESHORT(op,x); } outlen++; } while(0)
size_t outlen = 0;
int expect = 0;
uint8_t c;
uint32_t v = 0, vmin = 0;
while (len--) {
c = *str++;
if (expect) {
if ((c & 0xc0) != 0x80) {
expect = 0;
return -1;
} else {
v = (v << 6) | (c & 0x3f);
if (!--expect) {
if (v < vmin || v > 0x10ffff ||
(v >= 0xd800 && v <= 0xdfff)) {
return -1;
} else if (v > 0xffff) {
v -= 0x10000;
EMIT(0xd800 | (v >> 10));
EMIT(0xdc00 | (v & 0x3ff));
} else {
EMIT(v);
}
}
continue;
}
}
if (c < 0x80) {
EMIT(c);
2008-06-15 12:07:09 +08:00
} else if (c < 0xc0 || c >= 0xfe) {
/* Invalid UTF-8 */
return -1;
} else if (c < 0xe0) {
v = c & 0x1f;
expect = 1;
vmin = 0x80;
} else if (c < 0xf0) {
v = c & 0x0f;
expect = 2;
vmin = 0x800;
} else if (c < 0xf8) {
v = c & 0x07;
expect = 3;
vmin = 0x10000;
} else if (c < 0xfc) {
v = c & 0x03;
expect = 4;
vmin = 0x200000;
} else {
v = c & 0x01;
expect = 5;
vmin = 0x4000000;
}
}
return expect ? (size_t)-1 : outlen << 1;
#undef EMIT
}
/*
* Convert a string in UTF-8 format to UTF-32LE
*/
static size_t utf8_to_32le(uint8_t *str, size_t len, char *op)
{
#define EMIT(x) do { if (op) { WRITELONG(op,x); } outlen++; } while(0)
size_t outlen = 0;
int expect = 0;
uint8_t c;
uint32_t v = 0, vmin = 0;
while (len--) {
c = *str++;
if (expect) {
if ((c & 0xc0) != 0x80) {
return -1;
} else {
v = (v << 6) | (c & 0x3f);
if (!--expect) {
if (v < vmin || (v >= 0xd800 && v <= 0xdfff)) {
return -1;
} else {
EMIT(v);
}
}
continue;
}
}
if (c < 0x80) {
EMIT(c);
2008-06-15 12:07:09 +08:00
} else if (c < 0xc0 || c >= 0xfe) {
/* Invalid UTF-8 */
return -1;
} else if (c < 0xe0) {
v = c & 0x1f;
expect = 1;
vmin = 0x80;
} else if (c < 0xf0) {
v = c & 0x0f;
expect = 2;
vmin = 0x800;
} else if (c < 0xf8) {
v = c & 0x07;
expect = 3;
vmin = 0x10000;
} else if (c < 0xfc) {
v = c & 0x03;
expect = 4;
vmin = 0x200000;
} else {
v = c & 0x01;
expect = 5;
vmin = 0x4000000;
}
}
return expect ? (size_t)-1 : outlen << 2;
#undef EMIT
}
typedef size_t (*transform_func)(uint8_t *, size_t, char *);
/*
* Apply a specific string transform and return it in a nasm_malloc'd
* buffer, returning the length. On error, returns (size_t)-1 and no
* buffer is allocated.
*/
size_t string_transform(char *str, size_t len, char **out, enum strfunc func)
{
/* This should match enum strfunc in nasm.h */
static const transform_func str_transforms[] = {
utf8_to_16le,
utf8_to_32le,
};
transform_func transform = str_transforms[func];
size_t outlen;
uint8_t *s = (uint8_t *)str;
char *buf;
outlen = transform(s, len, NULL);
if (outlen == (size_t)-1)
return -1;
*out = buf = nasm_malloc(outlen+1);
buf[outlen] = '\0'; /* Forcibly null-terminate the buffer */
return transform(s, len, buf);
}