X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FSupport%2Fregcomp.c;h=0b5b765f89e14556554761e6df78916b2ff8fa91;hb=487ecab8d41e70700ca27895127b99f955e31fd0;hp=cd018d5dc5bc4d3628dcacbff4d72b1cb0cfc53f;hpb=ee7110f0478cc90ffa419759e21557ed8d669562;p=oota-llvm.git

diff --git a/lib/Support/regcomp.c b/lib/Support/regcomp.c
index cd018d5dc5b..0b5b765f89e 100644
--- a/lib/Support/regcomp.c
+++ b/lib/Support/regcomp.c
@@ -303,6 +303,7 @@ p_ere_exp(struct parse *p)
 	sopno pos;
 	int count;
 	int count2;
+	int backrefnum;
 	sopno subno;
 	int wascaret = 0;
 
@@ -370,7 +371,34 @@ p_ere_exp(struct parse *p)
 	case '\\':
 		REQUIRE(MORE(), REG_EESCAPE);
 		c = GETNEXT();
-		ordinary(p, c);
+		if (c >= '1' && c <= '9') {
+			/* \[0-9] is taken to be a back-reference to a previously specified
+			 * matching group. backrefnum will hold the number. The matching
+			 * group must exist (i.e. if \4 is found there must have been at
+			 * least 4 matching groups specified in the pattern previously).
+			 */
+			backrefnum = c - '0';
+			if (p->pend[backrefnum] == 0) {
+				SETERROR(REG_ESUBREG);
+				break;
+			}
+
+			/* Make sure everything checks out and emit the sequence
+			 * that marks a back-reference to the parse structure.
+			 */
+			assert(backrefnum <= p->g->nsub);
+			EMIT(OBACK_, backrefnum);
+			assert(p->pbegin[backrefnum] != 0);
+			assert(OP(p->strip[p->pbegin[backrefnum]]) != OLPAREN);
+			assert(OP(p->strip[p->pend[backrefnum]]) != ORPAREN);
+			(void) dupl(p, p->pbegin[backrefnum]+1, p->pend[backrefnum]);
+			EMIT(O_BACK, backrefnum);
+			p->g->backrefs = 1;
+		} else {
+			/* Other chars are simply themselves when escaped with a backslash.
+			 */
+			ordinary(p, c);
+		}
 		break;
 	case '{':		/* okay as ordinary except if digit follows */
 		REQUIRE(!MORE() || !isdigit((uch)PEEK()), REG_BADRPT);
@@ -504,10 +532,10 @@ p_simp_re(struct parse *p,
 	sopno subno;
 #	define	BACKSL	(1<<CHAR_BIT)
 
-	pos = HERE();		/* repetion op, if any, covers from here */
+        pos = HERE(); /* repetition op, if any, covers from here */
 
-	assert(MORE());		/* caller should have ensured this */
-	c = GETNEXT();
+        assert(MORE()); /* caller should have ensured this */
+        c = GETNEXT();
 	if (c == '\\') {
 		REQUIRE(MORE(), REG_EESCAPE);
 		c = BACKSL | GETNEXT();
@@ -780,7 +808,7 @@ p_b_cclass(struct parse *p, cset *cs)
 	const char *u;
 	char c;
 
-	while (MORE() && isalpha(PEEK()))
+	while (MORE() && isalpha((uch)PEEK()))
 		NEXT();
 	len = p->next - sp;
 	for (cp = cclasses; cp->name != NULL; cp++)