Implement delete trap for proxies.

R=ager@chromium.org
BUG=1543
TEST=

Review URL: http://codereview.chromium.org/7369001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8660 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.cc

@@ -189,7 +189,7 @@ MaybeObject* Object::GetPropertyWithCallback(Object* receiver,
     AccessorInfo* data = AccessorInfo::cast(structure);
     Object* fun_obj = data->getter();
     v8::AccessorGetter call_fun = v8::ToCData<v8::AccessorGetter>(fun_obj);
-    HandleScope scope;
+    HandleScope scope(isolate);
     JSObject* self = JSObject::cast(receiver);
     JSObject* holder_handle = JSObject::cast(holder);
     Handle<String> key(name);
@@ -229,7 +229,7 @@ MaybeObject* Object::GetPropertyWithHandler(Object* receiver_raw,
                                             String* name_raw,
                                             Object* handler_raw) {
   Isolate* isolate = name_raw->GetIsolate();
-  HandleScope scope;
+  HandleScope scope(isolate);
   Handle<Object> receiver(receiver_raw);
   Handle<Object> name(name_raw);
   Handle<Object> handler(handler_raw);
@@ -2173,9 +2173,9 @@ MaybeObject* JSObject::SetPropertyWithFailedAccessCheck(
     }
   }
 
-  HandleScope scope;
-  Handle<Object> value_handle(value);
   Heap* heap = GetHeap();
+  HandleScope scope(heap->isolate());
+  Handle<Object> value_handle(value);
   heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_SET);
   return *value_handle;
 }
@@ -2202,7 +2202,7 @@ MUST_USE_RESULT MaybeObject* JSProxy::SetPropertyWithHandler(
     PropertyAttributes attributes,
     StrictModeFlag strict_mode) {
   Isolate* isolate = GetIsolate();
-  HandleScope scope;
+  HandleScope scope(isolate);
   Handle<Object> receiver(this);
   Handle<Object> name(name_raw);
   Handle<Object> value(value_raw);
@@ -2228,12 +2228,50 @@ MUST_USE_RESULT MaybeObject* JSProxy::SetPropertyWithHandler(
 }
 
 
+MUST_USE_RESULT MaybeObject* JSProxy::DeletePropertyWithHandler(
+    String* name_raw, DeleteMode mode) {
+  Isolate* isolate = GetIsolate();
+  HandleScope scope(isolate);
+  Handle<Object> receiver(this);
+  Handle<Object> name(name_raw);
+  Handle<Object> handler(this->handler());
+
+  // Extract trap function.
+  Handle<String> trap_name = isolate->factory()->LookupAsciiSymbol("delete");
+  Handle<Object> trap(v8::internal::GetProperty(handler, trap_name));
+  if (trap->IsUndefined()) {
+    Handle<Object> args[] = { handler, trap_name };
+    Handle<Object> error = isolate->factory()->NewTypeError(
+        "handler_trap_missing", HandleVector(args, ARRAY_SIZE(args)));
+    isolate->Throw(*error);
+    return Failure::Exception();
+  }
+
+  // Call trap function.
+  Object** args[] = { name.location() };
+  bool has_exception;
+  Handle<Object> result =
+      Execution::Call(trap, handler, ARRAY_SIZE(args), args, &has_exception);
+  if (has_exception) return Failure::Exception();
+
+  Object* bool_result = result->ToBoolean();
+  if (mode == STRICT_DELETION && bool_result == GetHeap()->false_value()) {
+    Handle<Object> args[] = { handler, trap_name };
+    Handle<Object> error = isolate->factory()->NewTypeError(
+        "handler_failed", HandleVector(args, ARRAY_SIZE(args)));
+    isolate->Throw(*error);
+    return Failure::Exception();
+  }
+  return bool_result;
+}
+
+
 MUST_USE_RESULT PropertyAttributes JSProxy::GetPropertyAttributeWithHandler(
     JSReceiver* receiver_raw,
     String* name_raw,
     bool* has_exception) {
   Isolate* isolate = GetIsolate();
-  HandleScope scope;
+  HandleScope scope(isolate);
   Handle<JSReceiver> receiver(receiver_raw);
   Handle<Object> name(name_raw);
   Handle<Object> handler(this->handler());
@@ -2322,7 +2360,7 @@ MaybeObject* JSObject::SetPropertyForResult(LookupResult* result,
   }
   if (result->IsReadOnly() && result->IsProperty()) {
     if (strict_mode == kStrictMode) {
-      HandleScope scope;
+      HandleScope scope(heap->isolate());
       Handle<String> key(name);
       Handle<Object> holder(this);
       Handle<Object> args[2] = { key, holder };
@@ -3176,6 +3214,15 @@ MaybeObject* JSObject::DeleteElement(uint32_t index, DeleteMode mode) {
 }
 
 
+MaybeObject* JSReceiver::DeleteProperty(String* name, DeleteMode mode) {
+  if (IsJSProxy()) {
+    return JSProxy::cast(this)->DeletePropertyWithHandler(name, mode);
+  } else {
+    return JSObject::cast(this)->DeleteProperty(name, mode);
+  }
+}
+
+
 MaybeObject* JSObject::DeleteProperty(String* name, DeleteMode mode) {
   Isolate* isolate = GetIsolate();
   // ECMA-262, 3rd, 8.6.2.5
@@ -7527,7 +7574,7 @@ void JSArray::Expand(int required_size) {
 
 
 static Failure* ArrayLengthRangeError(Heap* heap) {
-  HandleScope scope;
+  HandleScope scope(heap->isolate());
   return heap->isolate()->Throw(
       *FACTORY->NewRangeError("invalid_array_length",
           HandleVector<Object>(NULL, 0)));
@@ -7725,7 +7772,7 @@ MaybeObject* JSReceiver::SetPrototype(Object* value,
   // or [[Extensible]] must not violate the invariants defined in the preceding
   // paragraph.
   if (!this->map()->is_extensible()) {
-    HandleScope scope;
+    HandleScope scope(heap->isolate());
     Handle<Object> handle(this, heap->isolate());
     return heap->isolate()->Throw(
         *FACTORY->NewTypeError("non_extensible_proto",
@@ -7739,7 +7786,7 @@ MaybeObject* JSReceiver::SetPrototype(Object* value,
   for (Object* pt = value; pt != heap->null_value(); pt = pt->GetPrototype()) {
     if (JSObject::cast(pt) == this) {
       // Cycle detected.
-      HandleScope scope;
+      HandleScope scope(heap->isolate());
       return heap->isolate()->Throw(
           *FACTORY->NewError("cyclic_proto", HandleVector<Object>(NULL, 0)));
     }
@@ -8523,7 +8570,7 @@ MaybeObject* JSObject::SetElement(uint32_t index,
   if (IsAccessCheckNeeded()) {
     Heap* heap = GetHeap();
     if (!heap->isolate()->MayIndexedAccess(this, index, v8::ACCESS_SET)) {
-      HandleScope scope;
+      HandleScope scope(heap->isolate());
       Handle<Object> value_handle(value);
       heap->isolate()->ReportFailedAccessCheck(this, v8::ACCESS_SET);
       return *value_handle;
@@ -11069,11 +11116,11 @@ void NumberDictionary::RemoveNumberEntries(uint32_t from, uint32_t to) {
 
 template<typename Shape, typename Key>
 Object* Dictionary<Shape, Key>::DeleteProperty(int entry,
-                                               JSObject::DeleteMode mode) {
+                                               JSReceiver::DeleteMode mode) {
   Heap* heap = Dictionary<Shape, Key>::GetHeap();
   PropertyDetails details = DetailsAt(entry);
   // Ignore attributes if forcing a deletion.
-  if (details.IsDontDelete() && mode != JSObject::FORCE_DELETION) {
+  if (details.IsDontDelete() && mode != JSReceiver::FORCE_DELETION) {
     return heap->false_value();
   }
   SetEntry(entry, heap->null_value(), heap->null_value());

src/objects.h

@@ -1359,6 +1359,12 @@ class HeapNumber: public HeapObject {
 // JSObject and JSProxy.
 class JSReceiver: public HeapObject {
  public:
+  enum DeleteMode {
+    NORMAL_DELETION,
+    STRICT_DELETION,
+    FORCE_DELETION
+  };
+
   // Casting.
   static inline JSReceiver* cast(Object* obj);
 
@@ -1373,6 +1379,8 @@ class JSReceiver: public HeapObject {
                                            PropertyAttributes attributes,
                                            StrictModeFlag strict_mode);
 
+  MUST_USE_RESULT MaybeObject* DeleteProperty(String* name, DeleteMode mode);
+
   // Returns the class name ([[Class]] property in the specification).
   String* class_name();
 
@@ -1422,12 +1430,6 @@ class JSReceiver: public HeapObject {
 // caching.
 class JSObject: public JSReceiver {
  public:
-  enum DeleteMode {
-    NORMAL_DELETION,
-    STRICT_DELETION,
-    FORCE_DELETION
-  };
-
   enum ElementsKind {
     // The "fast" kind for tagged values. Must be first to make it possible
     // to efficiently check maps if they have fast elements.
@@ -6477,14 +6479,18 @@ class JSProxy: public JSReceiver {
   static inline JSProxy* cast(Object* obj);
 
   MUST_USE_RESULT MaybeObject* SetPropertyWithHandler(
-      String* name_raw,
-      Object* value_raw,
+      String* name,
+      Object* value,
       PropertyAttributes attributes,
       StrictModeFlag strict_mode);
 
+  MUST_USE_RESULT MaybeObject* DeletePropertyWithHandler(
+      String* name,
+      DeleteMode mode);
+
   MUST_USE_RESULT PropertyAttributes GetPropertyAttributeWithHandler(
       JSReceiver* receiver,
-      String* name_raw,
+      String* name,
       bool* has_exception);
 
   // Dispatched behavior.

src/runtime.cc

@@ -3872,7 +3872,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DefineOrRedefineAccessorProperty) {
        || result.type() == CONSTANT_FUNCTION)) {
     Object* ok;
     { MaybeObject* maybe_ok =
-          obj->DeleteProperty(name, JSObject::NORMAL_DELETION);
+          obj->DeleteProperty(name, JSReceiver::NORMAL_DELETION);
       if (!maybe_ok->ToObject(&ok)) return maybe_ok;
     }
   }
@@ -4126,24 +4126,25 @@ MaybeObject* Runtime::ForceSetObjectProperty(Isolate* isolate,
 
 
 MaybeObject* Runtime::ForceDeleteObjectProperty(Isolate* isolate,
-                                                Handle<JSObject> js_object,
+                                                Handle<JSReceiver> receiver,
                                                 Handle<Object> key) {
   HandleScope scope(isolate);
 
   // Check if the given key is an array index.
   uint32_t index;
-  if (key->ToArrayIndex(&index)) {
+  if (receiver->IsJSObject() && key->ToArrayIndex(&index)) {
     // In Firefox/SpiderMonkey, Safari and Opera you can access the
     // characters of a string using [] notation.  In the case of a
     // String object we just need to redirect the deletion to the
     // underlying string if the index is in range.  Since the
     // underlying string does nothing with the deletion, we can ignore
     // such deletions.
-    if (js_object->IsStringObjectWithCharacterAt(index)) {
+    if (receiver->IsStringObjectWithCharacterAt(index)) {
       return isolate->heap()->true_value();
     }
 
-    return js_object->DeleteElement(index, JSObject::FORCE_DELETION);
+    return JSObject::cast(*receiver)->DeleteElement(
+        index, JSReceiver::FORCE_DELETION);
   }
 
   Handle<String> key_string;
@@ -4158,7 +4159,7 @@ MaybeObject* Runtime::ForceDeleteObjectProperty(Isolate* isolate,
   }
 
   key_string->TryFlatten();
-  return js_object->DeleteProperty(*key_string, JSObject::FORCE_DELETION);
+  return receiver->DeleteProperty(*key_string, JSReceiver::FORCE_DELETION);
 }
 
 
@@ -4237,12 +4238,12 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DeleteProperty) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 3);
 
-  CONVERT_CHECKED(JSObject, object, args[0]);
+  CONVERT_CHECKED(JSReceiver, object, args[0]);
   CONVERT_CHECKED(String, key, args[1]);
   CONVERT_SMI_ARG_CHECKED(strict, 2);
   return object->DeleteProperty(key, (strict == kStrictMode)
-                                      ? JSObject::STRICT_DELETION
-                                      : JSObject::NORMAL_DELETION);
+                                      ? JSReceiver::STRICT_DELETION
+                                      : JSReceiver::NORMAL_DELETION);
 }
 
 
@@ -8198,9 +8199,9 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DeleteContextSlot) {
   // index is non-negative.
   Handle<JSObject> object = Handle<JSObject>::cast(holder);
   if (index >= 0) {
-    return object->DeleteElement(index, JSObject::NORMAL_DELETION);
+    return object->DeleteElement(index, JSReceiver::NORMAL_DELETION);
   } else {
-    return object->DeleteProperty(*name, JSObject::NORMAL_DELETION);
+    return object->DeleteProperty(*name, JSReceiver::NORMAL_DELETION);
   }
 }
 

src/runtime.h

@@ -636,7 +636,7 @@ class Runtime : public AllStatic {
 
   MUST_USE_RESULT static MaybeObject* ForceDeleteObjectProperty(
       Isolate* isolate,
-      Handle<JSObject> object,
+      Handle<JSReceiver> object,
       Handle<Object> key);
 
   MUST_USE_RESULT static MaybeObject* GetObjectProperty(

test/mjsunit/harmony/proxies.js

@@ -289,6 +289,50 @@ TestDefine(Proxy.create({
 
 
 
+// Property deletion (delete).
+
+var key
+function TestDelete(handler) {
+  var o = Proxy.create(handler)
+  assertEquals(true, delete o.a)
+  assertEquals("a", key)
+  assertEquals(true, delete o["b"])
+  assertEquals("b", key)
+
+  assertEquals(false, delete o.z1)
+  assertEquals("z1", key)
+  assertEquals(false, delete o["z2"])
+  assertEquals("z2", key);
+
+  (function() {
+    "use strict"
+    assertEquals(true, delete o.c)
+    assertEquals("c", key)
+    assertEquals(true, delete o["d"])
+    assertEquals("d", key)
+
+    assertThrows(function() { delete o.z3 }, TypeError)
+    assertEquals("z3", key)
+    assertThrows(function() { delete o["z4"] }, TypeError)
+    assertEquals("z4", key)
+  })()
+}
+
+TestDelete({
+  'delete': function(k) { key = k; return k < "z" }
+})
+TestDelete({
+  'delete': function(k) { return this.delete2(k) },
+  delete2: function(k) { key = k; return k < "z" }
+})
+TestDelete(Proxy.create({
+  get: function(pr, pk) {
+    return function(k) { key = k; return k < "z" }
+  }
+}))
+
+
+
 // Property descriptors (Object.getOwnPropertyDescriptor).
 
 function TestDescriptor(handler) {