Mercurial > projects > ldc
view dmd/utf.c @ 80:7299ff502248 trunk
[svn r84] Fixed: Returning from a void function from inside the try of a try-finally block was broken.
author | lindquist |
---|---|
date | Wed, 31 Oct 2007 22:35:39 +0100 |
parents | c53b6e3fe49a |
children |
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// utf.c // Copyright (c) 2003 by Digital Mars // All Rights Reserved // written by Walter Bright // http://www.digitalmars.com // License for redistribution is by either the Artistic License // in artistic.txt, or the GNU General Public License in gnu.txt. // See the included readme.txt for details. // Description of UTF-8 at: // http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8 #include <stdio.h> #include <assert.h> #include "utf.h" int utf_isValidDchar(dchar_t c) { return c < 0xD800 || (c > 0xDFFF && c <= 0x10FFFF && c != 0xFFFE && c != 0xFFFF); } /******************************************** * Decode a single UTF-8 character sequence. * Returns: * NULL success * !=NULL error message string */ char *utf_decodeChar(unsigned char *s, size_t len, size_t *pidx, dchar_t *presult) { dchar_t V; size_t i = *pidx; unsigned char u = s[i]; assert(i >= 0 && i < len); if (u & 0x80) { unsigned n; unsigned char u2; /* The following encodings are valid, except for the 5 and 6 byte * combinations: * 0xxxxxxx * 110xxxxx 10xxxxxx * 1110xxxx 10xxxxxx 10xxxxxx * 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx * 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx * 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx */ for (n = 1; ; n++) { if (n > 4) goto Lerr; // only do the first 4 of 6 encodings if (((u << n) & 0x80) == 0) { if (n == 1) goto Lerr; break; } } // Pick off (7 - n) significant bits of B from first byte of octet V = (dchar_t)(u & ((1 << (7 - n)) - 1)); if (i + (n - 1) >= len) goto Lerr; // off end of string /* The following combinations are overlong, and illegal: * 1100000x (10xxxxxx) * 11100000 100xxxxx (10xxxxxx) * 11110000 1000xxxx (10xxxxxx 10xxxxxx) * 11111000 10000xxx (10xxxxxx 10xxxxxx 10xxxxxx) * 11111100 100000xx (10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx) */ u2 = s[i + 1]; if ((u & 0xFE) == 0xC0 || (u == 0xE0 && (u2 & 0xE0) == 0x80) || (u == 0xF0 && (u2 & 0xF0) == 0x80) || (u == 0xF8 && (u2 & 0xF8) == 0x80) || (u == 0xFC && (u2 & 0xFC) == 0x80)) goto Lerr; // overlong combination for (unsigned j = 1; j != n; j++) { u = s[i + j]; if ((u & 0xC0) != 0x80) goto Lerr; // trailing bytes are 10xxxxxx V = (V << 6) | (u & 0x3F); } if (!utf_isValidDchar(V)) goto Lerr; i += n; } else { V = (dchar_t) u; i++; } assert(utf_isValidDchar(V)); *pidx = i; *presult = V; return NULL; Lerr: *presult = (dchar_t) s[i]; *pidx = i + 1; return "invalid UTF-8 sequence"; } /*************************************************** * Validate a UTF-8 string. * Returns: * NULL success * !=NULL error message string */ char *utf_validateString(unsigned char *s, size_t len) { size_t idx; char *err = NULL; dchar_t dc; for (idx = 0; idx < len; ) { err = utf_decodeChar(s, len, &idx, &dc); if (err) break; } return err; } /******************************************** * Decode a single UTF-16 character sequence. * Returns: * NULL success * !=NULL error message string */ char *utf_decodeWchar(unsigned short *s, size_t len, size_t *pidx, dchar_t *presult) { char *msg; size_t i = *pidx; unsigned u = s[i]; assert(i >= 0 && i < len); if (u & ~0x7F) { if (u >= 0xD800 && u <= 0xDBFF) { unsigned u2; if (i + 1 == len) { msg = "surrogate UTF-16 high value past end of string"; goto Lerr; } u2 = s[i + 1]; if (u2 < 0xDC00 || u2 > 0xDFFF) { msg = "surrogate UTF-16 low value out of range"; goto Lerr; } u = ((u - 0xD7C0) << 10) + (u2 - 0xDC00); i += 2; } else if (u >= 0xDC00 && u <= 0xDFFF) { msg = "unpaired surrogate UTF-16 value"; goto Lerr; } else if (u == 0xFFFE || u == 0xFFFF) { msg = "illegal UTF-16 value"; goto Lerr; } else i++; } else { i++; } assert(utf_isValidDchar(u)); *pidx = i; *presult = (dchar_t)u; return NULL; Lerr: *presult = (dchar_t)s[i]; *pidx = i + 1; return msg; }