Add support for tracking down leak of the hole value.

Review URL: http://codereview.chromium.org/149522

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2432 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/api.h

@@ -244,9 +244,10 @@ v8::internal::Handle<T> v8::internal::Handle<T>::EscapeFrom(
 
 // Implementations of ToLocal
 
-#define MAKE_TO_LOCAL(Name, From, To) \
+#define MAKE_TO_LOCAL(Name, From, To)                                       \
   Local<v8::To> Utils::Name(v8::internal::Handle<v8::internal::From> obj) { \
-    return Local<To>(reinterpret_cast<To*>(obj.location())); \
+    ASSERT(!obj->IsTheHole());                                              \
+    return Local<To>(reinterpret_cast<To*>(obj.location()));                \
   }
 
 MAKE_TO_LOCAL(ToLocal, Context, Context)

src/ia32/codegen-ia32.cc

@@ -7591,6 +7591,16 @@ void CEntryStub::GenerateCore(MacroAssembler* masm,
     __ dec(Operand::StaticVariable(scope_depth));
   }
 
+  // Make sure we're not trying to return 'the hole' from the runtime
+  // call as this may lead to crashes in the IC code later.
+  if (FLAG_debug_code) {
+    Label okay;
+    __ cmp(eax, Factory::the_hole_value());
+    __ j(not_equal, &okay);
+    __ int3();
+    __ bind(&okay);
+  }
+
   // Check for failure result.
   Label failure_returned;
   ASSERT(((kFailureTag + 1) & kFailureTagMask) == 0);