[runtime] Don't crash when trying to access manually constructed CallSite object.

src/messages.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/messages.h"
 
 #include "src/api.h"
 #include "src/execution.h"
 #include "src/isolate-inl.h"
 #include "src/keys.h"
@@ skipping 164 matching lines @@
     fun_ = Handle<JSFunction>::cast(maybe_function);
     receiver_ = JSObject::GetDataProperty(
         call_site_obj, isolate->factory()->call_site_receiver_symbol());
   } else {
     Handle<Object> maybe_wasm_func_index = JSObject::GetDataProperty(
         call_site_obj, isolate->factory()->call_site_wasm_func_index_symbol());
     if (!maybe_wasm_func_index->IsSmi()) {
       // invalid: neither javascript nor wasm
       return;
     }
+    Handle<Object> maybe_wasm_obj = JSObject::GetDataProperty(
+        call_site_obj, isolate->factory()->call_site_wasm_obj_symbol());
+    if (!maybe_wasm_obj->IsJSObject()) {
+      // invalid: neither javascript nor wasm
+      return;
+    }
     // wasm
-    wasm_obj_ = Handle<JSObject>::cast(JSObject::GetDataProperty(
-        call_site_obj, isolate->factory()->call_site_wasm_obj_symbol()));
+    wasm_obj_ = Handle<JSObject>::cast(maybe_wasm_obj);
     wasm_func_index_ = Smi::cast(*maybe_wasm_func_index)->value();
     DCHECK(static_cast<int>(wasm_func_index_) >= 0);
   }
 
   CHECK(JSObject::GetDataProperty(
             call_site_obj, isolate->factory()->call_site_position_symbol())
             ->ToInt32(&pos_));
 }
 
 
 Handle<Object> CallSite::GetFileName() {
   if (!IsJavaScript()) return isolate_->factory()->null_value();
   Object* script = fun_->shared()->script();
   if (!script->IsScript()) return isolate_->factory()->null_value();
   return Handle<Object>(Script::cast(script)->name(), isolate_);
 }
 
 
 Handle<Object> CallSite::GetFunctionName() {
   if (IsWasm()) {
-    MaybeHandle<String> name;
-    if (!wasm_obj_->IsUndefined()) {
-      name = wasm::GetWasmFunctionName(Handle<JSObject>::cast(wasm_obj_),
-                                       wasm_func_index_);
-    }
+    MaybeHandle<String> name = wasm::GetWasmFunctionName(
+        Handle<JSObject>::cast(wasm_obj_), wasm_func_index_);
     if (name.is_null()) return isolate_->factory()->null_value();
     return name.ToHandleChecked();
   }
   Handle<String> result = JSFunction::GetName(fun_);
   if (result->length() != 0) return result;
 
   Handle<Object> script(fun_->shared()->script(), isolate_);
   if (script->IsScript() &&
       Handle<Script>::cast(script)->compilation_type() ==
           Script::COMPILATION_TYPE_EVAL) {
@@ skipping 223 matching lines @@
       builder.AppendCharacter(*c);
     }
   }
 
   return builder.Finish();
 }
 
 
 }  // namespace internal
 }  // namespace v8