Expand ranges before compiling the regexp.

1 files changed, 152 insertions, 3 deletions

diff --git a/re.c b/re.c
index 7dcbe488..60fa517b 100644
--- a/re.c
+++ b/re.c
@@ -27,6 +27,7 @@
 
 static reg_syntax_t syn;
 static void check_bracket_exp(char *s, size_t len);
+static char *expand_range(char *s, size_t *len);
 
 /* make_regexp --- generate compiled regular expressions */
 
@@ -44,6 +45,9 @@ make_regexp(const char *s, size_t len, int ignorecase, int dfa, int canfatal)
 	static short first = TRUE;
 	static short no_dfa = FALSE;
 	int has_anchor = FALSE;
+	int may_have_range = 0;
+	char *newbuf;
+	size_t newlen;
 
 	/* The number of bytes in the current multibyte character.
 	   It is 0, when the current character is a singlebyte character.  */
@@ -152,13 +156,36 @@ make_regexp(const char *s, size_t len, int ignorecase, int dfa, int canfatal)
 			c = *src;
 			if (c == '^' || c == '$')
 				has_anchor = TRUE;
+			if (c == '[' || c == '-' || c == ']')
+				may_have_range++;
+
 			*dest++ = *src++;	/* not '\\' */
 		}
 		if (gawk_mb_cur_max > 1 && is_multibyte)
 			is_multibyte--;
 	} /* while */
 
-	*dest = '\0' ;	/* Only necessary if we print dest ? */
+	*dest = '\0';
+	len = dest - buf;
+
+	if (   ! do_posix
+	    && may_have_range >= 3
+	    && memchr(buf, '-', len) != NULL) {
+		newlen = len;
+		newbuf = expand_range(buf, & newlen);
+
+		/* song and dance since buf & buflen are static */
+		if (newlen > buflen) {
+			free(buf);
+			buf = newbuf;
+			buflen = newlen;
+		} else {
+			memcpy(buf, newbuf, newlen);
+			free(newbuf);
+		}
+		len = newlen;
+	}
+
 	emalloc(rp, Regexp *, sizeof(*rp), "make_regexp");
 	memset((char *) rp, 0, sizeof(*rp));
 	rp->dfareg = NULL;
@@ -196,7 +223,6 @@ make_regexp(const char *s, size_t len, int ignorecase, int dfa, int canfatal)
 	dfasyntax(syn | (ignorecase ? RE_ICASE : 0), ignorecase ? TRUE : FALSE, '\n');
 	re_set_syntax(syn);
 
-	len = dest - buf;
 	if ((rerr = re_compile_pattern(buf, len, &(rp->pat))) != NULL) {
 		refree(rp);
 		if (! canfatal) {
@@ -539,7 +565,7 @@ again:
 			count++;
 		else if (*sp == ']')
 			count--;
-		if (*sp == '-' && ! range_warned && count == 1
+		if (*sp == '-' && do_lint && ! range_warned && count == 1
 		    && sp[-1] != '[' && sp[1] != ']'
 		    && ! isdigit(sp[-1]) && ! isdigit(sp[1])) {
 			/* found a range, we think */
@@ -580,3 +606,126 @@ again:
 done:
 	s[length] = save;
 }
+
+/* add_char --- add a character to the buffer, grow it if needed */
+
+static void
+add_char(char **bufp, size_t *lenp, char ch, char **ptr)
+{
+	size_t newlen;
+	size_t offset;
+
+	if (*ptr - *bufp < *lenp) {
+		**ptr = ch;
+		(*ptr)++;
+		return;
+	}
+
+	/* have to grow the buffer and adjust the pointers */
+	offset = (*ptr - *bufp);
+	newlen = offset * 2;
+	erealloc(*bufp, char *, newlen + 2, "add_char");
+	*ptr = *bufp + offset;
+	**ptr = ch;
+	(*ptr)++;
+}
+
+/* expand_range --- turn [b-e] into [bcde] */
+
+static char *
+expand_range(char *s, size_t *lenp)
+{
+	int i;
+	int found = FALSE;
+	char *sp, *sp2, *newbuf;
+	size_t len;
+	int count = 0;
+	size_t newbuf_len = *lenp * 2;
+
+	emalloc(newbuf, char *, newbuf_len, "expand_range");
+
+	sp = s;
+	sp2 = newbuf;
+	len = *lenp;
+#define copy() (add_char(& newbuf, & newbuf_len, *sp++, & sp2), len--)
+#define copych(ch) (add_char(& newbuf, & newbuf_len, ch, & sp2))
+again:
+	while (len > 0) {
+		if (*sp == '\\') {
+			copy();
+			copy();
+		}
+		else if (*sp == '[') {
+			count++;
+			break;
+		}
+		else
+			copy();
+	}
+	if (len == 0)
+		goto done;
+
+	copy();		/* copy in the [ */
+	if (*sp == '-')	/* it's literal, just copy it and skip over */
+		copy();
+
+	while (count > 0 && len > 0) {
+		if (*sp == '\\') {
+			copy();
+			copy();
+			continue;
+		}
+		if (*sp == '[') {
+			count++;
+			copy();
+			continue;
+		}
+		if (*sp == ']') {
+			count--;
+			copy();
+			if (count == 0)
+				goto again;
+			else
+				continue;
+		}
+
+		if (count == 1) {
+			/* inside [...] but not inside [[:...:]] */
+			if (*sp == '-') {
+				int start, end;
+				char i;
+
+				if (sp[1] == ']') {	/* also literal */
+					copy();
+					continue;
+				}
+
+				/* It's a range, expand it. */
+				start = sp[-1];
+				if (sp[1] == '\\') {
+					sp++;
+					len--;
+				}
+				end = sp[1];
+				for (i = start + 1; i <= end; i++)
+					copych(i);
+				sp++;
+				len--;
+				continue;
+			}
+			else
+				copy();
+		} else {
+			copy();
+		}
+	}
+
+	if (len > 0)
+		goto again;
+
+done:
+	*lenp = sp2 - newbuf;
+	return newbuf;
+}
+#undef copy
+#undef copych