[api] Don't go to javascript to construct API functions

src/execution.cc

 // Copyright 2014 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/execution.h"
 
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
 #include "src/isolate-inl.h"
 #include "src/messages.h"
@@ skipping 41 matching lines @@
 
 namespace {
 
 MUST_USE_RESULT MaybeHandle<Object> Invoke(Isolate* isolate, bool is_construct,
                                            Handle<Object> target,
                                            Handle<Object> receiver, int argc,
                                            Handle<Object> args[],
                                            Handle<Object> new_target) {
   DCHECK(!receiver->IsJSGlobalObject());
 
+  // API callbacks can be called directly.
+  if (target->IsJSFunction() &&
+      Handle<JSFunction>::cast(target)->shared()->IsApiFunction()) {
+    Handle<JSFunction> function = Handle<JSFunction>::cast(target);
+    SaveContext save(isolate);
+    isolate->set_context(function->context());
+    // Do proper receiver conversion for non-strict mode api functions.
+    if (!receiver->IsJSReceiver() &&
+        is_sloppy(function->shared()->language_mode())) {
+      if (receiver->IsUndefined() || receiver->IsNull()) {
+        if (is_construct) {
+          receiver = isolate->factory()->the_hole_value();
+        } else {
+          receiver = handle(function->global_proxy(), isolate);
+        }
+      } else {
+        ASSIGN_RETURN_ON_EXCEPTION(isolate, receiver,
+                                   Object::ToObject(isolate, receiver), Object);
+      }
+    }
+    DCHECK(function->context()->global_object()->IsJSGlobalObject());
+    auto value = Builtins::InvokeApiFunction(is_construct, function, receiver,
+                                             argc, args);
+    bool has_exception = value.is_null();
+    DCHECK(has_exception == isolate->has_pending_exception());
+    if (has_exception) {
+      isolate->ReportPendingMessages();
+      return MaybeHandle<Object>();
+    } else {
+      isolate->clear_pending_message();
+    }
+    return value;
+  }
+
   // Entering JavaScript.
   VMState<JS> state(isolate);
   CHECK(AllowJavascriptExecution::IsAllowed(isolate));
   if (!ThrowOnJavascriptExecution::IsAllowed(isolate)) {
     isolate->ThrowIllegalOperation();
     isolate->ReportPendingMessages();
     return MaybeHandle<Object>();
   }
 
   // Placeholder for return value.
@@ skipping 52 matching lines @@
 MaybeHandle<Object> Execution::Call(Isolate* isolate, Handle<Object> callable,
                                     Handle<Object> receiver, int argc,
                                     Handle<Object> argv[]) {
   // Convert calls on global objects to be calls on the global
   // receiver instead to avoid having a 'this' pointer which refers
   // directly to a global object.
   if (receiver->IsJSGlobalObject()) {
     receiver =
         handle(Handle<JSGlobalObject>::cast(receiver)->global_proxy(), isolate);
   }
-
-  // api callbacks can be called directly.
-  if (callable->IsJSFunction() &&
-      Handle<JSFunction>::cast(callable)->shared()->IsApiFunction()) {
-    Handle<JSFunction> function = Handle<JSFunction>::cast(callable);
-    SaveContext save(isolate);
-    isolate->set_context(function->context());
-    // Do proper receiver conversion for non-strict mode api functions.
-    if (!receiver->IsJSReceiver() &&
-        is_sloppy(function->shared()->language_mode())) {
-      if (receiver->IsUndefined() || receiver->IsNull()) {
-        receiver = handle(function->global_proxy(), isolate);
-      } else {
-        ASSIGN_RETURN_ON_EXCEPTION(isolate, receiver,
-                                   Object::ToObject(isolate, receiver), Object);
-      }
-    }
-    DCHECK(function->context()->global_object()->IsJSGlobalObject());
-    auto value = Builtins::InvokeApiFunction(function, receiver, argc, argv);
-    bool has_exception = value.is_null();
-    DCHECK(has_exception == isolate->has_pending_exception());
-    if (has_exception) {
-      isolate->ReportPendingMessages();
-      return MaybeHandle<Object>();
-    } else {
-      isolate->clear_pending_message();
-    }
-    return value;
-  }
   return Invoke(isolate, false, callable, receiver, argc, argv,
                 isolate->factory()->undefined_value());
 }
 
 
 // static
 MaybeHandle<Object> Execution::New(Handle<JSFunction> constructor, int argc,
                                    Handle<Object> argv[]) {
   return New(constructor->GetIsolate(), constructor, constructor, argc, argv);
 }
 
 
 // static
 MaybeHandle<Object> Execution::New(Isolate* isolate, Handle<Object> constructor,
                                    Handle<Object> new_target, int argc,
                                    Handle<Object> argv[]) {
+  if (!constructor->IsConstructor() &&

[Toon Verwaest, 2016/03/01 17:30:35]

Move up to the fast-path in the is_construct case.
Simplify the condition; I presume you don't need the is_generator case for
example ...

+      (!constructor->IsJSFunction() ||
+       !Handle<JSFunction>::cast(constructor)->shared()->is_generator())) {
+    THROW_NEW_ERROR(isolate,
+                    NewTypeError(MessageTemplate::kNotConstructor, constructor),
+                    Object);
+  }
   return Invoke(isolate, true, constructor,
                 isolate->factory()->undefined_value(), argc, argv, new_target);
 }
 
 
 MaybeHandle<Object> Execution::TryCall(Isolate* isolate,
                                        Handle<Object> callable,
                                        Handle<Object> receiver, int argc,
                                        Handle<Object> args[],
                                        MaybeHandle<Object>* exception_out) {
@@ skipping 291 matching lines @@
 
   isolate_->counters()->stack_interrupts()->Increment();
   isolate_->counters()->runtime_profiler_ticks()->Increment();
   isolate_->runtime_profiler()->MarkCandidatesForOptimization();
 
   return isolate_->heap()->undefined_value();
 }
 
 }  // namespace internal
 }  // namespace v8