Replaced empty handle checks with MaybeHandles

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 494 matching lines @@
         CreateObjectLiteralBoilerplate(
             isolate,
             literals,
             constant_properties,
             should_have_fast_elements,
             has_function_literal));
     boilerplate = Handle<JSObject>::cast(raw_boilerplate);
 
     AllocationSiteCreationContext creation_context(isolate);
     site = creation_context.EnterNewScope();
-    RETURN_IF_EMPTY_HANDLE(isolate,
-                           JSObject::DeepWalk(boilerplate, &creation_context));
+    RETURN_FAILURE_ON_EXCEPTION(
+        isolate,
+        JSObject::DeepWalk(boilerplate, &creation_context));
     creation_context.ExitScope(site, boilerplate);
 
     // Update the functions literal and return the boilerplate.
     literals->set(literals_index, *site);
   } else {
     site = Handle<AllocationSite>::cast(literal_site);
     boilerplate = Handle<JSObject>(JSObject::cast(site->transition_info()),
                                    isolate);
   }
 
   AllocationSiteUsageContext usage_context(isolate, site, true);
   usage_context.EnterNewScope();
-  Handle<Object> copy = JSObject::DeepCopy(boilerplate, &usage_context);
+  MaybeHandle<Object> maybe_copy = JSObject::DeepCopy(
+      boilerplate, &usage_context);
   usage_context.ExitScope(site, boilerplate);
-  RETURN_IF_EMPTY_HANDLE(isolate, copy);
+  Handle<Object> copy;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, copy, maybe_copy);
   return *copy;
 }
 
 
 MUST_USE_RESULT static MaybeHandle<AllocationSite> GetLiteralAllocationSite(
     Isolate* isolate,
     Handle<FixedArray> literals,
     int literals_index,
     Handle<FixedArray> elements) {
   // Check if boilerplate exists. If not, create it first.
@@ skipping 37 matching lines @@
       GetLiteralAllocationSite(isolate, literals, literals_index, elements),
       JSObject);
 
   bool enable_mementos = (flags & ArrayLiteral::kDisableMementos) == 0;
   Handle<JSObject> boilerplate(JSObject::cast(site->transition_info()));
   AllocationSiteUsageContext usage_context(isolate, site, enable_mementos);
   usage_context.EnterNewScope();
   JSObject::DeepCopyHints hints = (flags & ArrayLiteral::kShallowElements) == 0
       ? JSObject::kNoHints
       : JSObject::kObjectIsShallowArray;
-  Handle<JSObject> copy = JSObject::DeepCopy(boilerplate, &usage_context,
-                                             hints);
+  MaybeHandle<JSObject> copy = JSObject::DeepCopy(boilerplate, &usage_context,
+                                                  hints);
   usage_context.ExitScope(site, boilerplate);
   return copy;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, RuntimeHidden_CreateArrayLiteral) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 4);
   CONVERT_ARG_HANDLE_CHECKED(FixedArray, literals, 0);
   CONVERT_SMI_ARG_CHECKED(literals_index, 1);
@@ skipping 1151 matching lines @@
   CONVERT_ARG_HANDLE_CHECKED(Object, prototype, 1);
   if (obj->IsAccessCheckNeeded() &&
       !isolate->MayNamedAccess(
           obj, isolate->factory()->proto_string(), v8::ACCESS_SET)) {
     isolate->ReportFailedAccessCheck(obj, v8::ACCESS_SET);
     RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
     return isolate->heap()->undefined_value();
   }
   if (obj->map()->is_observed()) {
     Handle<Object> old_value = GetPrototypeSkipHiddenPrototypes(isolate, obj);
-
-    Handle<Object> result = JSObject::SetPrototype(obj, prototype, true);
-    RETURN_IF_EMPTY_HANDLE(isolate, result);
+    Handle<Object> result;
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, result,
+        JSObject::SetPrototype(obj, prototype, true));
 
     Handle<Object> new_value = GetPrototypeSkipHiddenPrototypes(isolate, obj);
     if (!new_value->SameValue(*old_value)) {
       JSObject::EnqueueChangeRecord(obj, "setPrototype",
                                     isolate->factory()->proto_string(),
                                     old_value);
     }
     return *result;
   }
-  Handle<Object> result = JSObject::SetPrototype(obj, prototype, true);
-  RETURN_IF_EMPTY_HANDLE(isolate, result);
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      JSObject::SetPrototype(obj, prototype, true));
   return *result;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_IsInPrototypeChain) {
   HandleScope shs(isolate);
   ASSERT(args.length() == 2);
   // See ECMA-262, section 15.3.5.3, page 88 (steps 5 - 8).
   CONVERT_ARG_HANDLE_CHECKED(Object, O, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, V, 1);
@@ skipping 807 matching lines @@
   ASSERT(args.length() == 4);
   CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 0);
   CONVERT_ARG_HANDLE_CHECKED(String, subject, 1);
   // Due to the way the JS calls are constructed this must be less than the
   // length of a string, i.e. it is always a Smi.  We check anyway for security.
   CONVERT_SMI_ARG_CHECKED(index, 2);
   CONVERT_ARG_HANDLE_CHECKED(JSArray, last_match_info, 3);
   RUNTIME_ASSERT(index >= 0);
   RUNTIME_ASSERT(index <= subject->length());
   isolate->counters()->regexp_entry_runtime()->Increment();
-  Handle<Object> result = RegExpImpl::Exec(regexp,
-                                           subject,
-                                           index,
-                                           last_match_info);
-  RETURN_IF_EMPTY_HANDLE(isolate, result);
+  Handle<Object> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      RegExpImpl::Exec(regexp, subject, index, last_match_info));
   return *result;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, RuntimeHidden_RegExpConstructResult) {
   HandleScope handle_scope(isolate);
   ASSERT(args.length() == 3);
   CONVERT_SMI_ARG_CHECKED(size, 0);
   RUNTIME_ASSERT(size >= 0 && size <= FixedArray::kMaxLength);
   CONVERT_ARG_HANDLE_CHECKED(Object, index, 1);
@@ skipping 12219 matching lines @@
       to_kind = GetHoleyElementsKind(to_kind);
       // Update the allocation site info to reflect the advice alteration.
       site->SetElementsKind(to_kind);
     }
 
     // We should allocate with an initial map that reflects the allocation site
     // advice. Therefore we use AllocateJSObjectFromMap instead of passing
     // the constructor.
     Handle<Map> initial_map(constructor->initial_map(), isolate);
     if (to_kind != initial_map->elements_kind()) {
       initial_map = Map::AsElementsKind(initial_map, to_kind);

[mvstanton, 2014/04/22 09:15:10]

There isn't a way for Map::AsElementsKind to return a null handle.

-      RETURN_IF_EMPTY_HANDLE(isolate, initial_map);
     }
 
     // If we don't care to track arrays of to_kind ElementsKind, then
     // don't emit a memento for them.
     Handle<AllocationSite> allocation_site;
     if (AllocationSite::GetMode(to_kind) == TRACK_ALLOCATION_SITE) {
       allocation_site = site;
     }
 
     array = Handle<JSArray>::cast(factory->NewJSObjectFromMap(
@@ skipping 183 matching lines @@
   }
 }
 
 
 void Runtime::OutOfMemory() {
   Heap::FatalProcessOutOfMemory("CALL_AND_RETRY_LAST", true);
   UNREACHABLE();
 }
 
 } }  // namespace v8::internal