[es6] do not add caller/arguments to ES6 function definitions

src/factory.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/factory.h"
 
 #include "src/allocation-site-scopes.h"
 #include "src/base/bits.h"
 #include "src/conversions.h"
 #include "src/isolate-inl.h"
@@ skipping 1238 matching lines @@
 Handle<JSFunction> Factory::NewFunction(Handle<Map> map,
                                         Handle<String> name,
                                         MaybeHandle<Code> code) {
   Handle<Context> context(isolate()->native_context());
   Handle<SharedFunctionInfo> info = NewSharedFunctionInfo(name, code);
   DCHECK(is_sloppy(info->language_mode()) &&
          (map.is_identical_to(isolate()->sloppy_function_map()) ||
           map.is_identical_to(
               isolate()->sloppy_function_without_prototype_map()) ||
           map.is_identical_to(
-              isolate()->sloppy_function_with_readonly_prototype_map())));
+              isolate()->sloppy_function_with_readonly_prototype_map()) ||
+          map.is_identical_to(isolate()->strict_function_map())));
   return NewFunction(map, info, context);
 }
 
 
 Handle<JSFunction> Factory::NewFunction(Handle<String> name) {
   return NewFunction(
       isolate()->sloppy_function_map(), name, MaybeHandle<Code>());
 }
 
 
-Handle<JSFunction> Factory::NewFunctionWithoutPrototype(Handle<String> name,
-                                                        Handle<Code> code) {
-  return NewFunction(
-      isolate()->sloppy_function_without_prototype_map(), name, code);
+Handle<JSFunction> Factory::NewFunctionWithoutPrototype(
+    Handle<String> name, Handle<Code> code, bool use_empty_function_map) {
+  Handle<Map> map = use_empty_function_map

[arv (Not doing code reviews), 2015/03/26 12:46:43]

What does "empty function" mean here? It does not fit the actual code very well.

[caitp (gmail), 2015/03/26 13:00:17]

originally I was saving the map of the empty function in here --- I guess
"strict" works too though, maybe more clearly

[arv (Not doing code reviews), 2015/03/26 13:03:30]

strict sounds more correct here.

+      ? isolate()->strict_function_without_prototype_map()
+      : isolate()->sloppy_function_without_prototype_map();
+  return NewFunction(map, name, code);
 }
 
 
-Handle<JSFunction> Factory::NewFunction(Handle<String> name,
-                                        Handle<Code> code,
+Handle<JSFunction> Factory::NewFunction(Handle<String> name, Handle<Code> code,
                                         Handle<Object> prototype,
-                                        bool read_only_prototype) {
-  Handle<Map> map = read_only_prototype
-      ? isolate()->sloppy_function_with_readonly_prototype_map()
-      : isolate()->sloppy_function_map();
+                                        bool read_only_prototype,
+                                        bool use_empty_function_map) {
+  DCHECK(!use_empty_function_map || !read_only_prototype);
+  Handle<Map> map = use_empty_function_map
+      ? isolate()->strict_function_map()

[arv (Not doing code reviews), 2015/03/26 12:46:43]

Is there no strict function with readonly prototype?

[caitp (gmail), 2015/03/26 13:00:17]

well, technically strict_function_map() IS a readonly prototype --- the writable
prototype version is only kept around in the bootstrapper, though

[caitp (gmail), 2015/03/26 13:03:02]

wait, I'm wrong --- it's readonly during bootstrapping, and subsequently is
read/write (overwritten with the writable version map). so strict builtins can
have the readonly mode

[arv (Not doing code reviews), 2015/03/26 13:03:30]

Maybe add a DCHECK to make sure we don't get the invalid case here?

[caitp (gmail), 2015/03/26 13:46:01]

Done --- the DCHECK is now "!strict || !readonly_prototype ||
CheckBootstrapping()", which seems to work well enough (there's a bit of
granularity where it could potentially be wrong sometimes, but it's probably
unlikely since this isn't needed much).

I guess another alternative is just adding the rw and ro variants of the map to
Context, rather than having just one with different meanings at different times

+      : read_only_prototype
+            ? isolate()->sloppy_function_with_readonly_prototype_map()
+            : isolate()->sloppy_function_map();
   Handle<JSFunction> result = NewFunction(map, name, code);
   result->set_prototype_or_initial_map(*prototype);
   return result;
 }
 
 
 Handle<JSFunction> Factory::NewFunction(Handle<String> name, Handle<Code> code,
                                         Handle<Object> prototype,
                                         InstanceType type, int instance_size,
                                         bool read_only_prototype,
-                                        bool install_constructor) {
+                                        bool install_constructor,
+                                        bool use_empty_function_map) {
   // Allocate the function
   Handle<JSFunction> function = NewFunction(
-      name, code, prototype, read_only_prototype);
+      name, code, prototype, read_only_prototype, use_empty_function_map);
 
   ElementsKind elements_kind =
       type == JS_ARRAY_TYPE ? FAST_SMI_ELEMENTS : FAST_HOLEY_SMI_ELEMENTS;
   Handle<Map> initial_map = NewMap(type, instance_size, elements_kind);
   if (!function->shared()->is_generator()) {
     if (prototype->IsTheHole()) {
       prototype = NewFunctionPrototype(function);
     } else if (install_constructor) {
       JSObject::AddProperty(Handle<JSObject>::cast(prototype),
                             constructor_string(), function, DONT_ENUM);
@@ skipping 1013 matching lines @@
   return Handle<Object>::null();
 }
 
 
 Handle<Object> Factory::ToBoolean(bool value) {
   return value ? true_value() : false_value();
 }
 
 
 } }  // namespace v8::internal