LookupResult result(GetHeap()->isolate());
LocalLookupRealNamedProperty(name, &result);
if (result.IsProperty() && result.type() == CALLBACKS) {
- ASSERT(!result.IsDontDelete());
+ // Note that the result can actually have IsDontDelete() == true when we
+ // e.g. have to fall back to the slow case while adding a setter after
+ // successfully reusing a map transition for a getter. Nevertheless, this is
+ // OK, because the assertion only holds for the whole addition of both
+ // accessors, not for the addition of each part. See first comment in
+ // DefinePropertyAccessor below.
Object* obj = result.GetCallbackObject();
if (obj->IsAccessorPair()) {
return AccessorPair::cast(obj)->CopyWithoutTransitions();
Object* getter,
Object* setter,
PropertyAttributes attributes) {
+ // We could assert that the property is configurable here, but we would need
+ // to do a lookup, which seems to be a bit of overkill.
+ Heap* heap = GetHeap();
+ bool only_attribute_changes = getter->IsNull() && setter->IsNull();
+ if (HasFastProperties() && !only_attribute_changes) {
+ MaybeObject* getterOk = heap->undefined_value();
+ if (!getter->IsNull()) {
+ getterOk = DefineFastAccessor(name, ACCESSOR_GETTER, getter, attributes);
+ if (getterOk->IsFailure()) return getterOk;
+ }
+
+ MaybeObject* setterOk = heap->undefined_value();
+ if (getterOk != heap->null_value() && !setter->IsNull()) {
+ setterOk = DefineFastAccessor(name, ACCESSOR_SETTER, setter, attributes);
+ if (setterOk->IsFailure()) return setterOk;
+ }
+
+ if (getterOk != heap->null_value() && setterOk != heap->null_value()) {
+ return heap->undefined_value();
+ }
+ }
+
AccessorPair* accessors;
{ MaybeObject* maybe_accessors = CreateAccessorPairFor(name);
if (!maybe_accessors->To(&accessors)) return maybe_accessors;
}
+static MaybeObject* CreateFreshAccessor(JSObject* obj,
+ String* name,
+ AccessorComponent component,
+ Object* accessor,
+ PropertyAttributes attributes) {
+ // step 1: create a new getter/setter pair with only the accessor in it
+ Heap* heap = obj->GetHeap();
+ AccessorPair* accessors2;
+ { MaybeObject* maybe_accessors2 = heap->AllocateAccessorPair();
+ if (!maybe_accessors2->To(&accessors2)) return maybe_accessors2;
+ }
+ accessors2->set(component, accessor);
+
+ // step 2: create a copy of the descriptors, incl. the new getter/setter pair
+ Map* map1 = obj->map();
+ CallbacksDescriptor callbacks_descr2(name, accessors2, attributes);
+ DescriptorArray* descriptors2;
+ { MaybeObject* maybe_descriptors2 =
+ map1->instance_descriptors()->CopyInsert(&callbacks_descr2,
+ REMOVE_TRANSITIONS);
+ if (!maybe_descriptors2->To(&descriptors2)) return maybe_descriptors2;
+ }
+
+ // step 3: create a new map with the new descriptors
+ Map* map2;
+ { MaybeObject* maybe_map2 = map1->CopyDropDescriptors();
+ if (!maybe_map2->To(&map2)) return maybe_map2;
+ }
+ map2->set_instance_descriptors(descriptors2);
+
+ // step 4: create a new getter/setter pair with a transition to the new map
+ AccessorPair* accessors1;
+ { MaybeObject* maybe_accessors1 = heap->AllocateAccessorPair();
+ if (!maybe_accessors1->To(&accessors1)) return maybe_accessors1;
+ }
+ accessors1->set(component, map2);
+
+ // step 5: create a copy of the descriptors, incl. the new getter/setter pair
+ // with the transition
+ CallbacksDescriptor callbacks_descr1(name, accessors1, attributes);
+ DescriptorArray* descriptors1;
+ { MaybeObject* maybe_descriptors1 =
+ map1->instance_descriptors()->CopyInsert(&callbacks_descr1,
+ KEEP_TRANSITIONS);
+ if (!maybe_descriptors1->To(&descriptors1)) return maybe_descriptors1;
+ }
+
+ // step 6: everything went well so far, so we make our changes visible
+ obj->set_map(map2);
+ map1->set_instance_descriptors(descriptors1);
+ return obj;
+}
+
+
+static bool TransitionToSameAccessor(Object* map,
+ String* name,
+ AccessorComponent component,
+ Object* accessor,
+ PropertyAttributes attributes ) {
+ DescriptorArray* descs = Map::cast(map)->instance_descriptors();
+ int number = descs->SearchWithCache(name);
+ ASSERT(number != DescriptorArray::kNotFound);
+ Object* target_accessor =
+ AccessorPair::cast(descs->GetCallbacksObject(number))->get(component);
+ PropertyAttributes target_attributes = descs->GetDetails(number).attributes();
+ return target_accessor == accessor && target_attributes == attributes;
+}
+
+
+static MaybeObject* NewCallbackTransition(JSObject* obj,
+ String* name,
+ AccessorComponent component,
+ Object* accessor,
+ PropertyAttributes attributes,
+ AccessorPair* accessors2) {
+ // step 1: copy the old getter/setter pair and set the new accessor
+ AccessorPair* accessors3;
+ { MaybeObject* maybe_accessors3 = accessors2->CopyWithoutTransitions();
+ if (!maybe_accessors3->To(&accessors3)) return maybe_accessors3;
+ }
+ accessors3->set(component, accessor);
+
+ // step 2: create a copy of the descriptors, incl. the new getter/setter pair
+ Map* map2 = obj->map();
+ CallbacksDescriptor callbacks_descr3(name, accessors3, attributes);
+ DescriptorArray* descriptors3;
+ { MaybeObject* maybe_descriptors3 =
+ map2->instance_descriptors()->CopyInsert(&callbacks_descr3,
+ REMOVE_TRANSITIONS);
+ if (!maybe_descriptors3->To(&descriptors3)) return maybe_descriptors3;
+ }
+
+ // step 3: create a new map with the new descriptors
+ Map* map3;
+ { MaybeObject* maybe_map3 = map2->CopyDropDescriptors();
+ if (!maybe_map3->To(&map3)) return maybe_map3;
+ }
+ map3->set_instance_descriptors(descriptors3);
+
+ // step 4: everything went well so far, so we make our changes visible
+ obj->set_map(map3);
+ accessors2->set(component, map3);
+ return obj;
+}
+
+
+MaybeObject* JSObject::DefineFastAccessor(String* name,
+ AccessorComponent component,
+ Object* accessor,
+ PropertyAttributes attributes) {
+ ASSERT(accessor->IsSpecFunction() || accessor->IsUndefined());
+ LookupResult result(GetIsolate());
+ LocalLookup(name, &result);
+
+ // If we have a new property, create a fresh accessor plus a transition to it.
+ if (!result.IsFound()) {
+ return CreateFreshAccessor(this, name, component, accessor, attributes);
+ }
+
+ // If the property is not a JavaScript accessor, fall back to the slow case.
+ if (result.type() != CALLBACKS) return GetHeap()->null_value();
+ Object* callback_value = result.GetValue();
+ if (!callback_value->IsAccessorPair()) return GetHeap()->null_value();
+ AccessorPair* accessors = AccessorPair::cast(callback_value);
+
+ // Follow a callback transition, if there is a fitting one.
+ Object* entry = accessors->get(component);
+ if (entry->IsMap() &&
+ TransitionToSameAccessor(entry, name, component, accessor, attributes)) {
+ set_map(Map::cast(entry));
+ return this;
+ }
+
+ // When we re-add the same accessor again, there is nothing to do.
+ if (entry == accessor && result.GetAttributes() == attributes) return this;
+
+ // Only the other accessor has been set so far, create a new transition.
+ if (entry->IsTheHole()) {
+ return NewCallbackTransition(this,
+ name,
+ component,
+ accessor,
+ attributes,
+ accessors);
+ }
+
+ // Nothing from the above worked, so we have to fall back to the slow case.
+ return GetHeap()->null_value();
+}
+
+
MaybeObject* JSObject::DefineAccessor(AccessorInfo* info) {
Isolate* isolate = GetIsolate();
String* name = String::cast(info->name());
Object* AccessorPair::GetComponent(AccessorComponent component) {
- Object* accessor = (component == ACCESSOR_GETTER) ? getter() : setter();
- return accessor->IsTheHole() ? GetHeap()->undefined_value() : accessor;
+ Object* accessor = get(component);
+ return accessor->IsTheHole() ? GetHeap()->undefined_value() : accessor;
}
--- /dev/null
+// 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
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+// Handy abbreviations.
+var dp = Object.defineProperty;
+var gop = Object.getOwnPropertyDescriptor;
+
+function getter() { return 111; }
+function setter(x) { print(222); }
+function anotherGetter() { return 333; }
+function anotherSetter(x) { print(444); }
+var obj1, obj2;
+
+// Two objects with the same getter.
+obj1 = {};
+dp(obj1, "alpha", { get: getter });
+obj2 = {};
+dp(obj2, "alpha", { get: getter });
+assertTrue(%HaveSameMap(obj1, obj2));
+
+// Two objects with the same getter, oldskool.
+obj1 = {};
+obj1.__defineGetter__("bravo", getter);
+assertEquals(getter, obj1.__lookupGetter__("bravo"));
+obj2 = {};
+obj2.__defineGetter__("bravo", getter);
+assertEquals(getter, obj2.__lookupGetter__("bravo"));
+assertTrue(%HaveSameMap(obj1, obj2));
+
+// Two objects with the same setter.
+obj1 = {};
+dp(obj1, "charlie", { set: setter });
+obj2 = {};
+dp(obj2, "charlie", { set: setter });
+assertTrue(%HaveSameMap(obj1, obj2));
+
+// Two objects with the same setter, oldskool.
+obj1 = {};
+obj1.__defineSetter__("delta", setter);
+assertEquals(setter, obj1.__lookupSetter__("delta"));
+obj2 = {};
+obj2.__defineSetter__("delta", setter);
+assertEquals(setter, obj2.__lookupSetter__("delta"));
+assertTrue(%HaveSameMap(obj1, obj2));
+
+// Two objects with the same getter and setter.
+obj1 = {};
+dp(obj1, "foxtrot", { get: getter, set: setter });
+obj2 = {};
+dp(obj2, "foxtrot", { get: getter, set: setter });
+assertTrue(%HaveSameMap(obj1, obj2));
+
+// Two objects with the same getter and setter, set separately.
+obj1 = {};
+dp(obj1, "golf", { get: getter, configurable: true });
+dp(obj1, "golf", { set: setter, configurable: true });
+obj2 = {};
+dp(obj2, "golf", { get: getter, configurable: true });
+dp(obj2, "golf", { set: setter, configurable: true });
+assertTrue(%HaveSameMap(obj1, obj2));
+
+// Two objects with the same getter and setter, set separately, oldskool.
+obj1 = {};
+obj1.__defineGetter__("hotel", getter);
+obj1.__defineSetter__("hotel", setter);
+obj2 = {};
+obj2.__defineGetter__("hotel", getter);
+obj2.__defineSetter__("hotel", setter);
+assertTrue(%HaveSameMap(obj1, obj2));
+
+// Attribute-only change, shouldn't affect previous descriptor properties.
+obj1 = {};
+dp(obj1, "india", { get: getter, configurable: true, enumerable: true });
+assertEquals(getter, gop(obj1, "india").get);
+assertTrue(gop(obj1, "india").configurable);
+assertTrue(gop(obj1, "india").enumerable);
+dp(obj1, "india", { enumerable: false });
+assertEquals(getter, gop(obj1, "india").get);
+assertTrue(gop(obj1, "india").configurable);
+assertFalse(gop(obj1, "india").enumerable);
+
+// Attribute-only change, shouldn't affect objects with previously shared maps.
+obj1 = {};
+dp(obj1, "juliet", { set: setter, configurable: true, enumerable: false });
+assertEquals(setter, gop(obj1, "juliet").set);
+assertTrue(gop(obj1, "juliet").configurable);
+assertFalse(gop(obj1, "juliet").enumerable);
+obj2 = {};
+dp(obj2, "juliet", { set: setter, configurable: true, enumerable: false });
+assertEquals(setter, gop(obj2, "juliet").set);
+assertTrue(gop(obj2, "juliet").configurable);
+assertFalse(gop(obj2, "juliet").enumerable);
+dp(obj1, "juliet", { set: setter, configurable: false, enumerable: true });
+assertEquals(setter, gop(obj1, "juliet").set);
+assertFalse(gop(obj1, "juliet").configurable);
+assertTrue(gop(obj1, "juliet").enumerable);
+assertEquals(setter, gop(obj2, "juliet").set);
+assertTrue(gop(obj2, "juliet").configurable);
+assertFalse(gop(obj2, "juliet").enumerable);
+
+// Two objects with the different getters.
+obj1 = {};
+dp(obj1, "kilo", { get: getter });
+obj2 = {};
+dp(obj2, "kilo", { get: anotherGetter });
+assertEquals(getter, gop(obj1, "kilo").get);
+assertEquals(anotherGetter, gop(obj2, "kilo").get);
+assertFalse(%HaveSameMap(obj1, obj2));
+
+// Two objects with the same getters and different setters.
+obj1 = {};
+dp(obj1, "lima", { get: getter, set: setter });
+obj2 = {};
+dp(obj2, "lima", { get: getter, set: anotherSetter });
+assertEquals(setter, gop(obj1, "lima").set);
+assertEquals(anotherSetter, gop(obj2, "lima").set);
+assertFalse(%HaveSameMap(obj1, obj2));
+
+// Even 'undefined' is a kind of getter.
+obj1 = {};
+dp(obj1, "mike", { get: undefined });
+assertTrue("mike" in obj1);
+assertEquals(undefined, gop(obj1, "mike").get);
+assertEquals(undefined, obj1.__lookupGetter__("mike"));
+assertEquals(undefined, gop(obj1, "mike").set);
+assertEquals(undefined, obj1.__lookupSetter__("mike"));
+
+// Even 'undefined' is a kind of setter.
+obj1 = {};
+dp(obj1, "november", { set: undefined });
+assertTrue("november" in obj1);
+assertEquals(undefined, gop(obj1, "november").get);
+assertEquals(undefined, obj1.__lookupGetter__("november"));
+assertEquals(undefined, gop(obj1, "november").set);
+assertEquals(undefined, obj1.__lookupSetter__("november"));
+
+// Redefining a data property.
+obj1 = {};
+obj1.oscar = 12345;
+dp(obj1, "oscar", { set: setter });
+assertEquals(setter, gop(obj1, "oscar").set);
+
+// Re-adding the same getter/attributes pair.
+obj1 = {};
+dp(obj1, "papa", { get: getter, configurable: true });
+dp(obj1, "papa", { get: getter, set: setter, configurable: true });
+assertEquals(getter, gop(obj1, "papa").get);
+assertEquals(setter, gop(obj1, "papa").set);
+assertTrue(gop(obj1, "papa").configurable);
+assertFalse(gop(obj1, "papa").enumerable);
projects / platform / upstream / v8.git / commitdiff