Improve the error message for handle check failure to list the actual

vm/object.h

Index: vm/object.h
===================================================================
--- vm/object.h	(revision 10133)
+++ vm/object.h	(working copy)
@@ -62,7 +62,8 @@
         reinterpret_cast<object*>(VMHandles::AllocateHandle(isolate));         \
     initializeHandle(obj, raw_ptr);                                            \
     if (!obj->Is##object()) {                                                  \
-      FATAL("Handle check failed.");                                           \
+      FATAL2("Handle check failed: saw %s expected %s",                        \
+             obj->GetClassName(), #object);                                    \

[Ivan Posva, 2012/08/03 20:13:10]

What would happen if you used ToCString() here, instead of adding
GetClassName()?

     }                                                                          \
     return *obj;                                                               \
   }                                                                            \
@@ -86,7 +87,8 @@
         VMHandles::AllocateZoneHandle(isolate));                               \
     initializeHandle(obj, raw_ptr);                                            \
     if (!obj->Is##object()) {                                                  \
-      FATAL("Handle check failed.");                                           \
+      FATAL2("Handle check failed: saw %s expected %s",                        \
+             obj->GetClassName(), #object);                                    \
     }                                                                          \
     return *obj;                                                               \
   }                                                                            \
@@ -104,6 +106,7 @@
     return reinterpret_cast<Raw##object*>(Object::null());                     \
   }                                                                            \
   virtual const char* ToCString() const;                                       \
+  virtual const char* GetClassName() const { return #object; }                 \
   static const ObjectKind kInstanceKind = k##object;                           \
  protected:  /* NOLINT */                                                      \
   object() : super() {}                                                        \
@@ -225,6 +228,9 @@
       return "Object";
     }
   }
+  virtual const char* GetClassName() const {
+    return "Object";
+  }
 
   bool IsNew() const { return raw()->IsNewObject(); }
   bool IsOld() const { return raw()->IsOldObject(); }