int relex()

in tools/dev/awk/b.c [764:846]
79 lines of code
34 McCabe index (conditional complexity)

int relex(void)		/* lexical analyzer for reparse */
{
	int c, n;
	int cflag;
	static uschar *buf = 0;
	static int bufsz = 100;
	uschar *bp;
	struct charclass *cc;
	int i;

	switch (c = *prestr++) {
	case '|': return OR;
	case '*': return STAR;
	case '+': return PLUS;
	case '?': return QUEST;
	case '.': return DOT;
	case '\0': prestr--; return '\0';
	case '^':
	case '$':
	case '(':
	case ')':
		return c;
	case '\\':
		rlxval = quoted((char **) &prestr);
		return CHAR;
	default:
		rlxval = c;
		return CHAR;
	case '[': 
		if (buf == 0 && (buf = (uschar *) malloc(bufsz)) == NULL)
			FATAL("out of space in reg expr %.10s..", lastre);
		bp = buf;
		if (*prestr == '^') {
			cflag = 1;
			prestr++;
		}
		else
			cflag = 0;
		n = 2 * strlen((const char *) prestr)+1;
		if (!adjbuf((char **) &buf, &bufsz, n, n, (char **) &bp, "relex1"))
			FATAL("out of space for reg expr %.10s...", lastre);
		for (; ; ) {
			if ((c = *prestr++) == '\\') {
				*bp++ = '\\';
				if ((c = *prestr++) == '\0')
					FATAL("nonterminated character class %.20s...", lastre);
				*bp++ = c;
			/* } else if (c == '\n') { */
			/* 	FATAL("newline in character class %.20s...", lastre); */
			} else if (c == '[' && *prestr == ':') {
				/* POSIX char class names, Dag-Erling Smorgrav, des@ofug.org */
				for (cc = charclasses; cc->cc_name; cc++)
					if (strncmp((const char *) prestr + 1, (const char *) cc->cc_name, cc->cc_namelen) == 0)
						break;
				if (cc->cc_name != NULL && prestr[1 + cc->cc_namelen] == ':' &&
				    prestr[2 + cc->cc_namelen] == ']') {
					prestr += cc->cc_namelen + 3;
					for (i = 0; i < NCHARS; i++) {
						if (!adjbuf((char **) &buf, &bufsz, bp-buf+1, 100, (char **) &bp, "relex2"))
						    FATAL("out of space for reg expr %.10s...", lastre);
						if (cc->cc_func(i)) {
							*bp++ = i;
							n++;
						}
					}
				} else
					*bp++ = c;
			} else if (c == '\0') {
				FATAL("nonterminated character class %.20s", lastre);
			} else if (bp == buf) {	/* 1st char is special */
				*bp++ = c;
			} else if (c == ']') {
				*bp++ = 0;
				rlxstr = (uschar *) tostring((char *) buf);
				if (cflag == 0)
					return CCL;
				else
					return NCCL;
			} else
				*bp++ = c;
		}
	}
}