From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Sat, 2 Jan 2016 17:27:45 +0000 (+0000)
Subject: Check accumulated parameter before entering recursion.
X-Git-Tag: 0.16~1^2~15
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ec0a3f36ef000d121b15325917786689fc5605cb;p=re2c

Check accumulated parameter before entering recursion.
---

diff --git a/re2c/src/ir/skeleton/control_flow.cc b/re2c/src/ir/skeleton/control_flow.cc
index a015ffb5..74166865 100644
--- a/re2c/src/ir/skeleton/control_flow.cc
+++ b/re2c/src/ir/skeleton/control_flow.cc
@@ -16,36 +16,27 @@ namespace re2c
 // We don't need all patterns that cause undefined behaviour.
 // We only need some examples, the shorter the better.
 // See also note [counting skeleton edges].
-Node::nakeds_t Node::naked_ways (way_t & prefix, std::vector<way_t> & ways)
+void Node::naked_ways (way_t & prefix, std::vector<way_t> & ways, nakeds_t &size)
 {
 	if (!rule.rank.is_none ())
 	{
-		return nakeds_t::from32(0u);
+		return;
 	}
 	else if (end ())
 	{
 		ways.push_back (prefix);
-		return nakeds_t::from64(prefix.size ());
+		size = size + nakeds_t::from64(prefix.size ());
 	}
 	else if (loop < 2)
 	{
 		local_inc _ (loop);
-		nakeds_t size = nakeds_t::from32(0u);
-		for (arcsets_t::iterator i = arcsets.begin (); i != arcsets.end (); ++i)
+		for (arcsets_t::iterator i = arcsets.begin ();
+			i != arcsets.end () && !size.overflow (); ++i)
 		{
 			prefix.push_back (&i->second);
-			size = size + i->first->naked_ways (prefix, ways);
+			i->first->naked_ways (prefix, ways, size);
 			prefix.pop_back ();
-			if (size.overflow ())
-			{
-				return nakeds_t::limit ();
-			}
 		}
-		return size;
-	}
-	else
-	{
-		return nakeds_t::from32(0u);
 	}
 }
 
@@ -53,12 +44,15 @@ void Skeleton::warn_undefined_control_flow ()
 {
 	way_t prefix;
 	std::vector<way_t> ways;
-	const bool overflow = nodes->naked_ways (prefix, ways).overflow ();
+	Node::nakeds_t size = Node::nakeds_t::from32(0u);
+
+	nodes->naked_ways (prefix, ways, size);
+
 	if (!ways.empty ())
 	{
-		warn.undefined_control_flow (line, cond, ways, overflow);
+		warn.undefined_control_flow (line, cond, ways, size.overflow ());
 	}
-	else if (overflow)
+	else if (size.overflow ())
 	{
 		warn.fail (Warn::UNDEFINED_CONTROL_FLOW, line, "DFA is too large to check undefined control flow");
 	}
diff --git a/re2c/src/ir/skeleton/generate_data.cc b/re2c/src/ir/skeleton/generate_data.cc
index bebca172..13e9f8a7 100644
--- a/re2c/src/ir/skeleton/generate_data.cc
+++ b/re2c/src/ir/skeleton/generate_data.cc
@@ -53,9 +53,8 @@ template <typename cunit_t, typename key_t>
  *
  */
 template <typename cunit_t, typename key_t>
-	Node::covers_t Node::cover (path_t & prefix, FILE * input, FILE * keys)
+	void Node::cover (path_t & prefix, FILE * input, FILE * keys, covers_t &size)
 {
-	covers_t size = covers_t::from32(0u);
 	if (end () && suffix == NULL)
 	{
 		suffix = new path_t (rule, ctx);
@@ -63,20 +62,17 @@ template <typename cunit_t, typename key_t>
 	if (suffix != NULL)
 	{
 		prefix.append (suffix);
-		size = cover_one<cunit_t, key_t> (input, keys, prefix);
+		size = size + cover_one<cunit_t, key_t> (input, keys, prefix);
 	}
 	else if (loop < 2)
 	{
 		local_inc _ (loop);
-		for (arcs_t::iterator i = arcs.begin (); i != arcs.end (); ++i)
+		for (arcs_t::iterator i = arcs.begin ();
+			i != arcs.end () && !size.overflow(); ++i)
 		{
 			path_t new_prefix = prefix;
 			new_prefix.extend (i->first->rule, i->first->ctx, &i->second);
-			size = size + i->first->cover<cunit_t, key_t> (new_prefix, input, keys);
-			if (size.overflow ())
-			{
-				return covers_t::limit ();
-			}
+			i->first->cover<cunit_t, key_t> (new_prefix, input, keys, size);
 			if (i->first->suffix != NULL && suffix == NULL)
 			{
 				suffix = new path_t (rule, ctx);
@@ -85,14 +81,17 @@ template <typename cunit_t, typename key_t>
 			}
 		}
 	}
-	return size;
 }
 
 template <typename cunit_t, typename key_t>
 	void Skeleton::generate_paths_cunit_key (FILE * input, FILE * keys)
 {
 	path_t prefix (nodes->rule, nodes->ctx);
-	if (nodes->cover<cunit_t, key_t> (prefix, input, keys).overflow ())
+	Node::covers_t size = Node::covers_t::from32(0u);
+
+	nodes->cover<cunit_t, key_t> (prefix, input, keys, size);
+
+	if (size.overflow ())
 	{
 		warning
 			( NULL
diff --git a/re2c/src/ir/skeleton/skeleton.h b/re2c/src/ir/skeleton/skeleton.h
index dedca8ac..8a754fd9 100644
--- a/re2c/src/ir/skeleton/skeleton.h
+++ b/re2c/src/ir/skeleton/skeleton.h
@@ -97,8 +97,8 @@ struct Node
 	void calc_dist ();
 	void calc_reachable ();
 	template <typename cunit_t, typename key_t>
-		covers_t cover (path_t & prefix, FILE * input, FILE * keys);
-	nakeds_t naked_ways (way_t & prefix, std::vector<way_t> & ways);
+		void cover (path_t & prefix, FILE * input, FILE * keys, covers_t &size);
+	void naked_ways (way_t & prefix, std::vector<way_t> & ways, nakeds_t &size);
 
 	FORBID_COPY (Node);
 };