Avoid SetPropertyInternal if the LookupIterator is NotFound

src/objects.cc

 // Copyright 2015 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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 4113 matching lines @@
   MAYBE_RETURN_NULL(SetProperty(&it, value, language_mode, store_mode));
   return value;
 }
 
 
 Maybe<bool> Object::SetPropertyInternal(LookupIterator* it,
                                         Handle<Object> value,
                                         LanguageMode language_mode,
                                         StoreFromKeyed store_mode,
                                         bool* found) {
-  it->UpdateProtector();
+  DCHECK(it->IsFound());
   ShouldThrow should_throw =
       is_sloppy(language_mode) ? DONT_THROW : THROW_ON_ERROR;
 
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
   AssertNoContextChange ncc(it->isolate());
 
-  for (; it->IsFound(); it->Next()) {
+  do {
     switch (it->state()) {
       case LookupIterator::NOT_FOUND:
         UNREACHABLE();
 
       case LookupIterator::ACCESS_CHECK:
         if (it->HasAccess()) break;
         // Check whether it makes sense to reuse the lookup iterator. Here it
         // might still call into setters up the prototype chain.
         return JSObject::SetPropertyWithFailedAccessCheck(it, value,
                                                           should_throw);
@@ skipping 42 matching lines @@
           return WriteToReadOnlyProperty(it, value, should_throw);
         }
         if (it->HolderIsReceiverOrHiddenPrototype()) {
           return SetDataProperty(it, value);
         }
       // Fall through.
       case LookupIterator::TRANSITION:
         *found = false;
         return Nothing<bool>();
     }
-  }
+    it->Next();
+  } while (it->IsFound());
 
   *found = false;
   return Nothing<bool>();
 }
 
 
 Maybe<bool> Object::SetProperty(LookupIterator* it, Handle<Object> value,
                                 LanguageMode language_mode,
                                 StoreFromKeyed store_mode) {
-  bool found = true;
-  Maybe<bool> result =
-      SetPropertyInternal(it, value, language_mode, store_mode, &found);
-  if (found) return result;
+  it->UpdateProtector();
+  if (it->IsFound()) {
+    bool found = true;
+    Maybe<bool> result =
+        SetPropertyInternal(it, value, language_mode, store_mode, &found);
+    if (found) return result;
+  }
 
   // If the receiver is the JSGlobalObject, the store was contextual. In case
   // the property did not exist yet on the global object itself, we have to
   // throw a reference error in strict mode.  In sloppy mode, we continue.
   if (is_strict(language_mode) && it->GetReceiver()->IsJSGlobalObject()) {
     it->isolate()->Throw(*it->isolate()->factory()->NewReferenceError(
         MessageTemplate::kNotDefined, it->name()));
     return Nothing<bool>();
   }
 
   ShouldThrow should_throw =
       is_sloppy(language_mode) ? DONT_THROW : THROW_ON_ERROR;
   return AddDataProperty(it, value, NONE, should_throw, store_mode);
 }
 
 
 Maybe<bool> Object::SetSuperProperty(LookupIterator* it, Handle<Object> value,
                                      LanguageMode language_mode,
                                      StoreFromKeyed store_mode) {
   Isolate* isolate = it->isolate();
 
-  bool found = true;
-  Maybe<bool> result =
-      SetPropertyInternal(it, value, language_mode, store_mode, &found);
-  if (found) return result;
+  it->UpdateProtector();
+  if (it->IsFound()) {
+    bool found = true;
+    Maybe<bool> result =
+        SetPropertyInternal(it, value, language_mode, store_mode, &found);
+    if (found) return result;
+  }
 
   // The property either doesn't exist on the holder or exists there as a data
   // property.
 
   ShouldThrow should_throw =
       is_sloppy(language_mode) ? DONT_THROW : THROW_ON_ERROR;
 
   if (!it->GetReceiver()->IsJSReceiver()) {
     return WriteToReadOnlyProperty(it, value, should_throw);
   }
@@ skipping 54 matching lines @@
         return JSReceiver::DefineOwnProperty(isolate, receiver, it->GetName(),
                                              &value_desc, should_throw);
       }
 
       case LookupIterator::NOT_FOUND:
       case LookupIterator::TRANSITION:
         UNREACHABLE();
     }
   }
 
-  return JSObject::AddDataProperty(&own_lookup, value, NONE, should_throw,
-                                   store_mode);
+  return AddDataProperty(&own_lookup, value, NONE, should_throw, store_mode);
 }
 
 MaybeHandle<Object> Object::ReadAbsentProperty(LookupIterator* it) {
   return it->isolate()->factory()->undefined_value();
 }
 
 MaybeHandle<Object> Object::ReadAbsentProperty(Isolate* isolate,
                                                Handle<Object> receiver,
                                                Handle<Object> name) {
   return isolate->factory()->undefined_value();
@@ skipping 15435 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8