1 /*
2 * Copyright (c) 2021 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include "ecmascript/js_generator_object.h"
17
18 #include "ecmascript/generator_helper.h"
19 #include "ecmascript/js_iterator.h"
20 #include "ecmascript/js_tagged_value-inl.h"
21
22 namespace panda::ecmascript {
GeneratorValidate(JSThread * thread,const JSHandle<JSTaggedValue> & obj)23 JSGeneratorState JSGeneratorObject::GeneratorValidate(JSThread *thread, const JSHandle<JSTaggedValue> &obj)
24 {
25 // 1.Perform ? RequireInternalSlot(generator, [[GeneratorState]]).
26 // 2.Assert: generator also has a [[GeneratorContext]] internal slot.
27 if (!obj->IsECMAObject()) {
28 THROW_TYPE_ERROR_AND_RETURN(thread, "", JSGeneratorState::UNDEFINED);
29 }
30 JSHandle<JSObject> toObj = JSTaggedValue::ToObject(thread, obj);
31 if (!toObj->IsGeneratorObject()) {
32 THROW_TYPE_ERROR_AND_RETURN(thread, "", JSGeneratorState::UNDEFINED);
33 }
34
35 // 3.Let state be generator.[[GeneratorState]].
36 JSHandle<JSGeneratorObject> generator(thread, JSGeneratorObject::Cast(*(toObj)));
37 JSGeneratorState state = generator->GetGeneratorState();
38 // 4.If state is executing, throw a TypeError exception.
39 if (state == JSGeneratorState::EXECUTING) {
40 THROW_TYPE_ERROR_AND_RETURN(thread, "", JSGeneratorState::UNDEFINED);
41 }
42 // 5.Return state.
43 return state;
44 }
45
GeneratorResume(JSThread * thread,const JSHandle<JSGeneratorObject> & generator,JSTaggedValue value)46 JSHandle<JSObject> JSGeneratorObject::GeneratorResume(JSThread *thread, const JSHandle<JSGeneratorObject> &generator,
47 JSTaggedValue value)
48 {
49 // 1.Let state be ? GeneratorValidate(generator).
50 JSHandle<JSTaggedValue> gen(thread, generator.GetTaggedValue());
51 JSGeneratorState state = GeneratorValidate(thread, gen);
52 RETURN_HANDLE_IF_ABRUPT_COMPLETION(JSObject, thread);
53
54 // 2.If state is completed, return CreateIterResultObject(undefined, true).
55 if (state == JSGeneratorState::COMPLETED) {
56 JSHandle<JSTaggedValue> valueHandle(thread, JSTaggedValue::Undefined());
57 return JSIterator::CreateIterResultObject(thread, valueHandle, true);
58 }
59
60 // 3.Assert: state is either suspendedStart or suspendedYield.
61 ASSERT_PRINT(state == JSGeneratorState::SUSPENDED_START ||
62 state == JSGeneratorState::SUSPENDED_YIELD,
63 "state is neither suspendedStart nor suspendedYield");
64
65 // 4.Let genContext be generator.[[GeneratorContext]].
66 JSHandle<GeneratorContext> genContext(thread, generator->GetGeneratorContext());
67
68 // 5.Let methodContext be the running execution context.
69 // 6.Suspend methodContext.
70
71 // 7.Set generator.[[GeneratorState]] to executing.
72 generator->SetGeneratorState(JSGeneratorState::EXECUTING);
73
74 // 8.Push genContext onto the execution context stack; genContext is now the running execution context.
75 // 9.Resume the suspended evaluation of genContext using NormalCompletion(value) as the result of the operation
76 // that suspended it. Let result be the value returned by the resumed computation.
77 // 10.Assert: When we return here, genContext has already been removed from the execution context stack and
78 // methodContext is the currently running execution context.
79 // 11.Return Completion(result).
80 JSHandle<JSObject> result = GeneratorHelper::Next(thread, genContext, value);
81 return result;
82 }
83
GeneratorResumeAbrupt(JSThread * thread,const JSHandle<JSGeneratorObject> & generator,const JSHandle<CompletionRecord> & abruptCompletion)84 JSHandle<JSObject> JSGeneratorObject::GeneratorResumeAbrupt(JSThread *thread,
85 const JSHandle<JSGeneratorObject> &generator,
86 const JSHandle<CompletionRecord> &abruptCompletion)
87 {
88 // 1.Let state be ? GeneratorValidate(generator).
89 JSHandle<JSTaggedValue> gen(thread, generator.GetTaggedValue());
90 JSGeneratorState state = GeneratorValidate(thread, gen);
91 RETURN_HANDLE_IF_ABRUPT_COMPLETION(JSObject, thread);
92
93 // 2.If state is suspendedStart, then
94 // a.Set generator.[[GeneratorState]] to completed.
95 // b.Once a generator enters the completed state it never leaves it and its associated execution context is
96 // never resumed. Any execution state associated with generator can be discarded at this point.
97 // c.Set state to completed.
98 if (state == JSGeneratorState::SUSPENDED_START) {
99 state = JSGeneratorState::COMPLETED;
100 generator->SetGeneratorState(state);
101 }
102
103 // 3.If state is completed, then
104 // a.If abruptCompletion.[[Type]] is return, then
105 // i.Return CreateIterResultObject(abruptCompletion.[[Value]], true).
106 // b.Return Completion(abruptCompletion).
107 if (state == JSGeneratorState::COMPLETED) {
108 JSHandle<JSTaggedValue> valueHandle(thread, abruptCompletion->GetValue());
109 JSHandle<JSObject> result = JSIterator::CreateIterResultObject(thread, valueHandle, true);
110 if (abruptCompletion->GetType() == CompletionRecordType::RETURN) {
111 return result;
112 }
113 THROW_NEW_ERROR_AND_RETURN_VALUE(thread, valueHandle.GetTaggedValue(), result);
114 }
115
116 // 4.Assert: state is suspendedYield.
117 ASSERT_PRINT(state == JSGeneratorState::SUSPENDED_YIELD, "state is not suspendedYield");
118
119 // 5.Let genContext be generator.[[GeneratorContext]].
120 JSHandle<GeneratorContext> genContext(thread, generator->GetGeneratorContext());
121
122 // 6.Let methodContext be the running execution context.
123 // 7.Suspend methodContext.
124
125 // 8.Set generator.[[GeneratorState]] to executing.
126 generator->SetGeneratorState(JSGeneratorState::EXECUTING);
127
128 // 9.Push genContext onto the execution context stack; genContext is now the running execution context.
129 // 10.Resume the suspended evaluation of genContext using abruptCompletion as the result of the operation that
130 // suspended it. Let result be the completion record returned by the resumed computation.
131 // 11.Assert: When we return here, genContext has already been removed from the execution context stack and
132 // methodContext is the currently running execution context.
133 // 12.Return Completion(result).
134 JSHandle<JSObject> result;
135 if (abruptCompletion->GetType() == CompletionRecordType::RETURN) {
136 result = GeneratorHelper::Return(thread, genContext, abruptCompletion->GetValue());
137 } else {
138 result = GeneratorHelper::Throw(thread, genContext, abruptCompletion->GetValue());
139 }
140 return result;
141 }
142 } // namespace panda::ecmascript
143