Check the depth of the constructed HEnvironment.

Temporary check to catch 1727 on the reliability bot.

R=fschneider@chromium.org
BUG=v8:1727

Review URL: http://codereview.chromium.org/8055010

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9452 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -6472,6 +6472,7 @@ void HEnvironment::Initialize(const HEnvironment* other) {
   pop_count_ = other->pop_count_;
   push_count_ = other->push_count_;
   ast_id_ = other->ast_id_;
+  CheckDepth();
 }
 
 

src/hydrogen.h

@@ -448,6 +448,23 @@ class HEnvironment: public ZoneObject {
  private:
   explicit HEnvironment(const HEnvironment* other);
 
+  void CheckDepth() {
+    // Verify that we are not trying to create an
+    // impossibly deeply nested environment.
+    if (!FLAG_limit_inlining) return;
+
+    static const int kMaxDepth = 4;
+
+    int cnt = 0;
+    for (HEnvironment* env = this;
+         env != NULL && cnt <= kMaxDepth;  // Check cnt to avoid infinite loop.
+         env = env->outer()) {
+      cnt++;
+    }
+
+    CHECK(cnt <= kMaxDepth);
+  }
+
   // True if index is included in the expression stack part of the environment.
   bool HasExpressionAt(int index) const;