wine/unicode/utf8.c

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2000-08-11 00:44:33 +00:00
/*
* UTF-8 support routines
*
* Copyright 2000 Alexandre Julliard
*/
#include <string.h>
#include "winnls.h"
#include "wine/unicode.h"
/* number of following bytes in sequence based on first byte value (for bytes above 0x7f) */
static const char utf8_length[128] =
{
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x80-0x8f */
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x90-0x9f */
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0xa0-0xaf */
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0xb0-0xbf */
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 0xc0-0xcf */
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 0xd0-0xdf */
2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, /* 0xe0-0xef */
3,3,3,3,3,3,3,3,4,4,4,4,5,5,0,0 /* 0xf0-0xff */
};
/* first byte mask depending on UTF-8 sequence length */
static const unsigned char utf8_mask[6] = { 0x7f, 0x1f, 0x0f, 0x07, 0x03, 0x01 };
/* minimum Unicode value depending on UTF-8 sequence length */
static const unsigned int utf8_minval[6] = { 0x0, 0x80, 0x800, 0x10000, 0x200000, 0x4000000 };
/* query necessary dst length for src string */
inline static int get_length_wcs_utf8( const WCHAR *src, unsigned int srclen )
{
int len;
for (len = 0; srclen; srclen--, src++, len++)
{
if (*src >= 0x80)
{
len++;
if (*src >= 0x800) len++;
}
}
return len;
}
/* wide char to UTF-8 string conversion */
/* return -1 on dst buffer overflow */
int utf8_wcstombs( const WCHAR *src, int srclen, char *dst, int dstlen )
{
int ret = srclen;
if (!dstlen) return get_length_wcs_utf8( src, srclen );
for (ret = srclen; srclen; srclen--, src++)
{
WCHAR ch = *src;
if (ch < 0x80) /* 0x00-0x7f: 1 byte */
{
if (!dstlen--) return -1; /* overflow */
*dst++ = ch;
continue;
}
if (ch < 0x800) /* 0x80-0x7ff: 2 bytes */
{
if ((dstlen -= 2) < 0) return -1; /* overflow */
dst[1] = 0x80 | (ch & 0x3f);
ch >>= 6;
dst[0] = 0xc0 | ch;
dst += 2;
continue;
}
/* 0x800-0xffff: 3 bytes */
if ((dstlen -= 3) < 0) return -1; /* overflow */
dst[2] = 0x80 | (ch & 0x3f);
ch >>= 6;
dst[1] = 0x80 | (ch & 0x3f);
ch >>= 6;
dst[0] = 0xe0 | ch;
dst += 3;
}
return ret;
}
/* query necessary dst length for src string */
inline static int get_length_mbs_utf8( const unsigned char *src, int srclen )
{
int ret;
const unsigned char *srcend = src + srclen;
for (ret = 0; src < srcend; ret++)
{
unsigned char ch = *src++;
if (ch < 0xc0) continue;
switch(utf8_length[ch-0x80])
{
case 5:
if (src >= srcend) return ret; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) continue;
src++;
case 4:
if (src >= srcend) return ret; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) continue;
src++;
case 3:
if (src >= srcend) return ret; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) continue;
src++;
case 2:
if (src >= srcend) return ret; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) continue;
src++;
case 1:
if (src >= srcend) return ret; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) continue;
src++;
}
}
return ret;
}
/* UTF-8 to wide char string conversion */
/* return -1 on dst buffer overflow, -2 on invalid input char */
int utf8_mbstowcs( int flags, const char *src, int srclen, WCHAR *dst, int dstlen )
{
int len, count;
unsigned int res;
const char *srcend = src + srclen;
if (!dstlen) return get_length_mbs_utf8( src, srclen );
for (count = dstlen; count && (src < srcend); count--, dst++)
{
unsigned char ch = *src++;
if (ch < 0x80) /* special fast case for 7-bit ASCII */
{
*dst = ch;
continue;
}
len = utf8_length[ch-0x80];
res = ch & utf8_mask[len];
switch(len)
{
case 5:
if (src >= srcend) goto done; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) goto bad;
res = (res << 6) | ch;
src++;
case 4:
if (src >= srcend) goto done; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) goto bad;
res = (res << 6) | ch;
src++;
case 3:
if (src >= srcend) goto done; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) goto bad;
res = (res << 6) | ch;
src++;
case 2:
if (src >= srcend) goto done; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) goto bad;
res = (res << 6) | ch;
src++;
case 1:
if (src >= srcend) goto done; /* ignore partial char */
if ((ch = *src ^ 0x80) >= 0x40) goto bad;
res = (res << 6) | ch;
src++;
if (res < utf8_minval[len]) goto bad;
if (res >= 0x10000) goto bad; /* FIXME: maybe we should do surrogates here */
*dst = res;
continue;
}
bad:
if (flags & MB_ERR_INVALID_CHARS) return -2; /* bad char */
*dst = (WCHAR)'?';
}
if (src < srcend) return -1; /* overflow */
done:
return dstlen - count;
}