Line data Source code
1 : // Copyright 2011 the V8 project authors. All rights reserved.
2 : // Use of this source code is governed by a BSD-style license that can be
3 : // found in the LICENSE file.
4 :
5 : #include "src/property-descriptor.h"
6 :
7 : #include "src/bootstrapper.h"
8 : #include "src/factory.h"
9 : #include "src/isolate-inl.h"
10 : #include "src/lookup.h"
11 : #include "src/objects-inl.h"
12 : #include "src/objects/property-descriptor-object-inl.h"
13 :
14 : namespace v8 {
15 : namespace internal {
16 :
17 : namespace {
18 :
19 : // Helper function for ToPropertyDescriptor. Comments describe steps for
20 : // "enumerable", other properties are handled the same way.
21 : // Returns false if an exception was thrown.
22 37953 : bool GetPropertyIfPresent(Handle<JSReceiver> receiver, Handle<String> name,
23 : Handle<Object>* value) {
24 37953 : LookupIterator it(receiver, name, receiver);
25 : // 4. Let hasEnumerable be HasProperty(Obj, "enumerable").
26 37953 : Maybe<bool> has_property = JSReceiver::HasProperty(&it);
27 : // 5. ReturnIfAbrupt(hasEnumerable).
28 37953 : if (has_property.IsNothing()) return false;
29 : // 6. If hasEnumerable is true, then
30 37953 : if (has_property.FromJust() == true) {
31 : // 6a. Let enum be ToBoolean(Get(Obj, "enumerable")).
32 : // 6b. ReturnIfAbrupt(enum).
33 24454 : if (!Object::GetProperty(&it).ToHandle(value)) return false;
34 : }
35 : return true;
36 : }
37 :
38 :
39 : // Helper function for ToPropertyDescriptor. Handles the case of "simple"
40 : // objects: nothing on the prototype chain, just own fast data properties.
41 : // Must not have observable side effects, because the slow path will restart
42 : // the entire conversion!
43 631009 : bool ToPropertyDescriptorFastPath(Isolate* isolate, Handle<JSReceiver> obj,
44 : PropertyDescriptor* desc) {
45 317405 : if (!obj->IsJSObject()) return false;
46 : Map* map = Handle<JSObject>::cast(obj)->map();
47 316694 : if (map->instance_type() != JS_OBJECT_TYPE) return false;
48 316332 : if (map->is_access_check_needed()) return false;
49 632664 : if (map->prototype() != *isolate->initial_object_prototype()) return false;
50 : // During bootstrapping, the object_function_prototype_map hasn't been
51 : // set up yet.
52 313604 : if (isolate->bootstrapper()->IsActive()) return false;
53 313604 : if (JSObject::cast(map->prototype())->map() !=
54 627208 : isolate->native_context()->object_function_prototype_map()) {
55 : return false;
56 : }
57 : // TODO(jkummerow): support dictionary properties?
58 312334 : if (map->is_dictionary_map()) return false;
59 : Handle<DescriptorArray> descs =
60 : Handle<DescriptorArray>(map->instance_descriptors());
61 1805828 : for (int i = 0; i < map->NumberOfOwnDescriptors(); i++) {
62 591868 : PropertyDetails details = descs->GetDetails(i);
63 : Name* key = descs->GetKey(i);
64 : Handle<Object> value;
65 591868 : if (details.location() == kField) {
66 591759 : if (details.kind() == kData) {
67 : value = JSObject::FastPropertyAt(Handle<JSObject>::cast(obj),
68 : details.representation(),
69 1183518 : FieldIndex::ForDescriptor(map, i));
70 : } else {
71 : DCHECK_EQ(kAccessor, details.kind());
72 : // Bail out to slow path.
73 : return false;
74 : }
75 :
76 : } else {
77 : DCHECK_EQ(kDescriptor, details.location());
78 109 : if (details.kind() == kData) {
79 : value = handle(descs->GetValue(i), isolate);
80 : } else {
81 : DCHECK_EQ(kAccessor, details.kind());
82 : // Bail out to slow path.
83 : return false;
84 : }
85 : }
86 1898503 : Heap* heap = isolate->heap();
87 591858 : if (key == heap->enumerable_string()) {
88 86816 : desc->set_enumerable(value->BooleanValue());
89 505042 : } else if (key == heap->configurable_string()) {
90 55552 : desc->set_configurable(value->BooleanValue());
91 449490 : } else if (key == heap->value_string()) {
92 : desc->set_value(value);
93 275652 : } else if (key == heap->writable_string()) {
94 218767 : desc->set_writable(value->BooleanValue());
95 56885 : } else if (key == heap->get_string()) {
96 : // Bail out to slow path to throw an exception if necessary.
97 37309 : if (!value->IsCallable()) return false;
98 : desc->set_get(value);
99 19576 : } else if (key == heap->set_string()) {
100 : // Bail out to slow path to throw an exception if necessary.
101 19312 : if (!value->IsCallable()) return false;
102 : desc->set_set(value);
103 : }
104 : }
105 940681 : if ((desc->has_get() || desc->has_set()) &&
106 44403 : (desc->has_value() || desc->has_writable())) {
107 : // Bail out to slow path to throw an exception.
108 : return false;
109 : }
110 310971 : return true;
111 : }
112 :
113 :
114 1667 : void CreateDataProperty(Isolate* isolate, Handle<JSObject> object,
115 : Handle<String> name, Handle<Object> value) {
116 1667 : LookupIterator it(object, name, object, LookupIterator::OWN_SKIP_INTERCEPTOR);
117 1667 : Maybe<bool> result = JSObject::CreateDataProperty(&it, value);
118 3334 : CHECK(result.IsJust() && result.FromJust());
119 1667 : }
120 :
121 : } // namespace
122 :
123 :
124 : // ES6 6.2.4.4 "FromPropertyDescriptor"
125 10597 : Handle<Object> PropertyDescriptor::ToObject(Isolate* isolate) {
126 : DCHECK(!(PropertyDescriptor::IsAccessorDescriptor(this) &&
127 : PropertyDescriptor::IsDataDescriptor(this)));
128 : Factory* factory = isolate->factory();
129 10597 : if (IsRegularAccessorProperty()) {
130 : // Fast case for regular accessor properties.
131 : Handle<JSObject> result = factory->NewJSObjectFromMap(
132 68 : isolate->accessor_property_descriptor_map());
133 : result->InObjectPropertyAtPut(JSAccessorPropertyDescriptor::kGetIndex,
134 68 : *get());
135 : result->InObjectPropertyAtPut(JSAccessorPropertyDescriptor::kSetIndex,
136 68 : *set());
137 : result->InObjectPropertyAtPut(
138 : JSAccessorPropertyDescriptor::kEnumerableIndex,
139 68 : isolate->heap()->ToBoolean(enumerable()));
140 : result->InObjectPropertyAtPut(
141 : JSAccessorPropertyDescriptor::kConfigurableIndex,
142 68 : isolate->heap()->ToBoolean(configurable()));
143 68 : return result;
144 : }
145 10529 : if (IsRegularDataProperty()) {
146 : // Fast case for regular data properties.
147 : Handle<JSObject> result =
148 9138 : factory->NewJSObjectFromMap(isolate->data_property_descriptor_map());
149 : result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kValueIndex,
150 9138 : *value());
151 : result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kWritableIndex,
152 9138 : isolate->heap()->ToBoolean(writable()));
153 : result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kEnumerableIndex,
154 9138 : isolate->heap()->ToBoolean(enumerable()));
155 : result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kConfigurableIndex,
156 9138 : isolate->heap()->ToBoolean(configurable()));
157 9138 : return result;
158 : }
159 1391 : Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
160 1391 : if (has_value()) {
161 938 : CreateDataProperty(isolate, result, factory->value_string(), value());
162 : }
163 1391 : if (has_writable()) {
164 : CreateDataProperty(isolate, result, factory->writable_string(),
165 198 : factory->ToBoolean(writable()));
166 : }
167 1391 : if (has_get()) {
168 114 : CreateDataProperty(isolate, result, factory->get_string(), get());
169 : }
170 1391 : if (has_set()) {
171 42 : CreateDataProperty(isolate, result, factory->set_string(), set());
172 : }
173 1391 : if (has_enumerable()) {
174 : CreateDataProperty(isolate, result, factory->enumerable_string(),
175 240 : factory->ToBoolean(enumerable()));
176 : }
177 1391 : if (has_configurable()) {
178 : CreateDataProperty(isolate, result, factory->configurable_string(),
179 708 : factory->ToBoolean(configurable()));
180 : }
181 1391 : return result;
182 : }
183 :
184 :
185 : // ES6 6.2.4.5
186 : // Returns false in case of exception.
187 : // static
188 317563 : bool PropertyDescriptor::ToPropertyDescriptor(Isolate* isolate,
189 : Handle<Object> obj,
190 : PropertyDescriptor* desc) {
191 : // 1. ReturnIfAbrupt(Obj).
192 : // 2. If Type(Obj) is not Object, throw a TypeError exception.
193 317563 : if (!obj->IsJSReceiver()) {
194 : isolate->Throw(*isolate->factory()->NewTypeError(
195 316 : MessageTemplate::kPropertyDescObject, obj));
196 158 : return false;
197 : }
198 : // 3. Let desc be a new Property Descriptor that initially has no fields.
199 : DCHECK(desc->is_empty());
200 :
201 317405 : Handle<JSReceiver> receiver = Handle<JSReceiver>::cast(obj);
202 317405 : if (ToPropertyDescriptorFastPath(isolate, receiver, desc)) {
203 : return true;
204 : }
205 :
206 : // enumerable?
207 : Handle<Object> enumerable;
208 : // 4 through 6b.
209 6434 : if (!GetPropertyIfPresent(receiver, isolate->factory()->enumerable_string(),
210 6434 : &enumerable)) {
211 : return false;
212 : }
213 : // 6c. Set the [[Enumerable]] field of desc to enum.
214 6398 : if (!enumerable.is_null()) {
215 964 : desc->set_enumerable(enumerable->BooleanValue());
216 : }
217 :
218 : // configurable?
219 : Handle<Object> configurable;
220 : // 7 through 9b.
221 6398 : if (!GetPropertyIfPresent(receiver, isolate->factory()->configurable_string(),
222 6398 : &configurable)) {
223 : return false;
224 : }
225 : // 9c. Set the [[Configurable]] field of desc to conf.
226 6398 : if (!configurable.is_null()) {
227 1415 : desc->set_configurable(configurable->BooleanValue());
228 : }
229 :
230 : // value?
231 : Handle<Object> value;
232 : // 10 through 12b.
233 6398 : if (!GetPropertyIfPresent(receiver, isolate->factory()->value_string(),
234 6398 : &value)) {
235 : return false;
236 : }
237 : // 12c. Set the [[Value]] field of desc to value.
238 6254 : if (!value.is_null()) desc->set_value(value);
239 :
240 : // writable?
241 : Handle<Object> writable;
242 : // 13 through 15b.
243 6254 : if (!GetPropertyIfPresent(receiver, isolate->factory()->writable_string(),
244 6254 : &writable)) {
245 : return false;
246 : }
247 : // 15c. Set the [[Writable]] field of desc to writable.
248 7633 : if (!writable.is_null()) desc->set_writable(writable->BooleanValue());
249 :
250 : // getter?
251 : Handle<Object> getter;
252 : // 16 through 18b.
253 6254 : if (!GetPropertyIfPresent(receiver, isolate->factory()->get_string(),
254 6254 : &getter)) {
255 : return false;
256 : }
257 6254 : if (!getter.is_null()) {
258 : // 18c. If IsCallable(getter) is false and getter is not undefined,
259 : // throw a TypeError exception.
260 3570 : if (!getter->IsCallable() && !getter->IsUndefined(isolate)) {
261 : isolate->Throw(*isolate->factory()->NewTypeError(
262 78 : MessageTemplate::kObjectGetterCallable, getter));
263 39 : return false;
264 : }
265 : // 18d. Set the [[Get]] field of desc to getter.
266 : desc->set_get(getter);
267 : }
268 : // setter?
269 : Handle<Object> setter;
270 : // 19 through 21b.
271 6215 : if (!GetPropertyIfPresent(receiver, isolate->factory()->set_string(),
272 6215 : &setter)) {
273 : return false;
274 : }
275 6215 : if (!setter.is_null()) {
276 : // 21c. If IsCallable(setter) is false and setter is not undefined,
277 : // throw a TypeError exception.
278 4394 : if (!setter->IsCallable() && !setter->IsUndefined(isolate)) {
279 : isolate->Throw(*isolate->factory()->NewTypeError(
280 58 : MessageTemplate::kObjectSetterCallable, setter));
281 29 : return false;
282 : }
283 : // 21d. Set the [[Set]] field of desc to setter.
284 : desc->set_set(setter);
285 : }
286 :
287 : // 22. If either desc.[[Get]] or desc.[[Set]] is present, then
288 : // 22a. If either desc.[[Value]] or desc.[[Writable]] is present,
289 : // throw a TypeError exception.
290 19310 : if ((desc->has_get() || desc->has_set()) &&
291 3908 : (desc->has_value() || desc->has_writable())) {
292 : isolate->Throw(*isolate->factory()->NewTypeError(
293 188 : MessageTemplate::kValueAndAccessor, obj));
294 94 : return false;
295 : }
296 :
297 : // 23. Return desc.
298 : return true;
299 : }
300 :
301 :
302 : // ES6 6.2.4.6
303 : // static
304 3897 : void PropertyDescriptor::CompletePropertyDescriptor(Isolate* isolate,
305 : PropertyDescriptor* desc) {
306 : // 1. ReturnIfAbrupt(Desc).
307 : // 2. Assert: Desc is a Property Descriptor.
308 : // 3. Let like be Record{
309 : // [[Value]]: undefined, [[Writable]]: false,
310 : // [[Get]]: undefined, [[Set]]: undefined,
311 : // [[Enumerable]]: false, [[Configurable]]: false}.
312 : // 4. If either IsGenericDescriptor(Desc) or IsDataDescriptor(Desc) is true,
313 : // then:
314 3897 : if (!IsAccessorDescriptor(desc)) {
315 : // 4a. If Desc does not have a [[Value]] field, set Desc.[[Value]] to
316 : // like.[[Value]].
317 3708 : if (!desc->has_value()) {
318 : desc->set_value(isolate->factory()->undefined_value());
319 : }
320 : // 4b. If Desc does not have a [[Writable]] field, set Desc.[[Writable]]
321 : // to like.[[Writable]].
322 3708 : if (!desc->has_writable()) desc->set_writable(false);
323 : } else {
324 : // 5. Else,
325 : // 5a. If Desc does not have a [[Get]] field, set Desc.[[Get]] to
326 : // like.[[Get]].
327 189 : if (!desc->has_get()) {
328 : desc->set_get(isolate->factory()->undefined_value());
329 : }
330 : // 5b. If Desc does not have a [[Set]] field, set Desc.[[Set]] to
331 : // like.[[Set]].
332 189 : if (!desc->has_set()) {
333 : desc->set_set(isolate->factory()->undefined_value());
334 : }
335 : }
336 : // 6. If Desc does not have an [[Enumerable]] field, set
337 : // Desc.[[Enumerable]] to like.[[Enumerable]].
338 3897 : if (!desc->has_enumerable()) desc->set_enumerable(false);
339 : // 7. If Desc does not have a [[Configurable]] field, set
340 : // Desc.[[Configurable]] to like.[[Configurable]].
341 3897 : if (!desc->has_configurable()) desc->set_configurable(false);
342 : // 8. Return Desc.
343 3897 : }
344 :
345 2162615 : Handle<PropertyDescriptorObject> PropertyDescriptor::ToPropertyDescriptorObject(
346 : Isolate* isolate) {
347 : Handle<PropertyDescriptorObject> obj = Handle<PropertyDescriptorObject>::cast(
348 2162615 : isolate->factory()->NewFixedArray(PropertyDescriptorObject::kLength));
349 :
350 : int flags =
351 4325230 : PropertyDescriptorObject::IsEnumerableBit::encode(enumerable_) |
352 4325230 : PropertyDescriptorObject::HasEnumerableBit::encode(has_enumerable_) |
353 4325230 : PropertyDescriptorObject::IsConfigurableBit::encode(configurable_) |
354 4325230 : PropertyDescriptorObject::HasConfigurableBit::encode(has_configurable_) |
355 4325230 : PropertyDescriptorObject::IsWritableBit::encode(writable_) |
356 4325230 : PropertyDescriptorObject::HasWritableBit::encode(has_writable_) |
357 2162615 : PropertyDescriptorObject::HasValueBit::encode(has_value()) |
358 2162615 : PropertyDescriptorObject::HasGetBit::encode(has_get()) |
359 2162615 : PropertyDescriptorObject::HasSetBit::encode(has_set());
360 :
361 : obj->set(PropertyDescriptorObject::kFlagsIndex, Smi::FromInt(flags));
362 :
363 : obj->set(PropertyDescriptorObject::kValueIndex,
364 4326206 : has_value() ? *value_ : isolate->heap()->the_hole_value());
365 : obj->set(PropertyDescriptorObject::kGetIndex,
366 6486869 : has_get() ? *get_ : isolate->heap()->the_hole_value());
367 : obj->set(PropertyDescriptorObject::kSetIndex,
368 6486869 : has_set() ? *set_ : isolate->heap()->the_hole_value());
369 :
370 2162615 : return obj;
371 : }
372 :
373 : } // namespace internal
374 : } // namespace v8
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