1 /*
2 * Copyright (c) 2021-2024 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_object-inl.h"
21 #include "ecmascript/js_tagged_value-inl.h"
22
23 namespace panda::ecmascript {
GeneratorValidate(JSThread * thread,const JSHandle<JSTaggedValue> & obj)24 JSGeneratorState JSGeneratorObject::GeneratorValidate(JSThread *thread, const JSHandle<JSTaggedValue> &obj)
25 {
26 // 1.Perform ? RequireInternalSlot(generator, [[GeneratorState]]).
27 // 2.Assert: generator also has a [[GeneratorContext]] internal slot.
28 if (!obj->IsECMAObject()) {
29 THROW_TYPE_ERROR_AND_RETURN(thread, "Is not object",
30 JSGeneratorState::UNDEFINED);
31 }
32 JSHandle<JSObject> toObj = JSTaggedValue::ToObject(thread, obj);
33 if (!toObj->IsGeneratorObject()) {
34 THROW_TYPE_ERROR_AND_RETURN(thread, "Is not generator object", JSGeneratorState::UNDEFINED);
35 }
36
37 // 3.Let state be generator.[[GeneratorState]].
38 JSHandle<JSGeneratorObject> generator(thread, JSGeneratorObject::Cast(*(toObj)));
39 JSGeneratorState state = generator->GetGeneratorState();
40 // 4.If state is executing, throw a TypeError exception.
41 if (state == JSGeneratorState::EXECUTING) {
42 THROW_TYPE_ERROR_AND_RETURN(thread, "State is executing", JSGeneratorState::UNDEFINED);
43 }
44 // 5.Return state.
45 return state;
46 }
47
GeneratorResume(JSThread * thread,const JSHandle<JSGeneratorObject> & generator,JSTaggedValue value)48 JSHandle<JSObject> JSGeneratorObject::GeneratorResume(JSThread *thread, const JSHandle<JSGeneratorObject> &generator,
49 JSTaggedValue value)
50 {
51 // 1.Let state be ? GeneratorValidate(generator).
52 JSHandle<JSTaggedValue> gen(thread, generator.GetTaggedValue());
53 JSGeneratorState state = GeneratorValidate(thread, gen);
54 RETURN_HANDLE_IF_ABRUPT_COMPLETION(JSObject, thread);
55
56 // 2.If state is completed, return CreateIterResultObject(undefined, true).
57 if (state == JSGeneratorState::COMPLETED) {
58 JSHandle<JSTaggedValue> valueHandle(thread, JSTaggedValue::Undefined());
59 return JSIterator::CreateIterResultObject(thread, valueHandle, true);
60 }
61
62 // 3.Assert: state is either suspendedStart or suspendedYield.
63 ASSERT_PRINT(state == JSGeneratorState::SUSPENDED_START ||
64 state == JSGeneratorState::SUSPENDED_YIELD,
65 "state is neither suspendedStart nor suspendedYield");
66
67 // 4.Let genContext be generator.[[GeneratorContext]].
68 JSHandle<GeneratorContext> genContext(thread, generator->GetGeneratorContext());
69
70 // 5.Let methodContext be the running execution context.
71 // 6.Suspend methodContext.
72
73 // 7.Set generator.[[GeneratorState]] to executing.
74 generator->SetGeneratorState(JSGeneratorState::EXECUTING);
75
76 // 8.Push genContext onto the execution context stack; genContext is now the running execution context.
77 // 9.Resume the suspended evaluation of genContext using NormalCompletion(value) as the result of the operation
78 // that suspended it. Let result be the value returned by the resumed computation.
79 // 10.Assert: When we return here, genContext has already been removed from the execution context stack and
80 // methodContext is the currently running execution context.
81 // 11.Return Completion(result).
82 JSHandle<JSObject> result = GeneratorHelper::Next(thread, genContext, value);
83 return result;
84 }
85
GeneratorResumeAbrupt(JSThread * thread,const JSHandle<JSGeneratorObject> & generator,const JSHandle<CompletionRecord> & abruptCompletion)86 JSHandle<JSObject> JSGeneratorObject::GeneratorResumeAbrupt(JSThread *thread,
87 const JSHandle<JSGeneratorObject> &generator,
88 const JSHandle<CompletionRecord> &abruptCompletion)
89 {
90 // 1.Let state be ? GeneratorValidate(generator).
91 JSHandle<JSTaggedValue> gen(thread, generator.GetTaggedValue());
92 JSGeneratorState state = GeneratorValidate(thread, gen);
93 RETURN_HANDLE_IF_ABRUPT_COMPLETION(JSObject, thread);
94
95 // 2.If state is suspendedStart, then
96 // a.Set generator.[[GeneratorState]] to completed.
97 // b.Once a generator enters the completed state it never leaves it and its associated execution context is
98 // never resumed. Any execution state associated with generator can be discarded at this point.
99 // c.Set state to completed.
100 if (state == JSGeneratorState::SUSPENDED_START) {
101 state = JSGeneratorState::COMPLETED;
102 generator->SetGeneratorState(state);
103 }
104
105 // 3.If state is completed, then
106 // a.If abruptCompletion.[[Type]] is return, then
107 // i.Return CreateIterResultObject(abruptCompletion.[[Value]], true).
108 // b.Return Completion(abruptCompletion).
109 if (state == JSGeneratorState::COMPLETED) {
110 JSHandle<JSTaggedValue> valueHandle(thread, abruptCompletion->GetValue());
111 JSHandle<JSObject> result = JSIterator::CreateIterResultObject(thread, valueHandle, true);
112 if (abruptCompletion->GetType() == CompletionRecordType::RETURN) {
113 return result;
114 }
115 THROW_NEW_ERROR_AND_RETURN_VALUE(thread, valueHandle.GetTaggedValue(), result);
116 }
117
118 // 4.Assert: state is suspendedYield.
119 ASSERT_PRINT(state == JSGeneratorState::SUSPENDED_YIELD, "state is not suspendedYield");
120
121 // 5.Let genContext be generator.[[GeneratorContext]].
122 JSHandle<GeneratorContext> genContext(thread, generator->GetGeneratorContext());
123
124 // 6.Let methodContext be the running execution context.
125 // 7.Suspend methodContext.
126
127 // 8.Set generator.[[GeneratorState]] to executing.
128 generator->SetGeneratorState(JSGeneratorState::EXECUTING);
129
130 // 9.Push genContext onto the execution context stack; genContext is now the running execution context.
131 // 10.Resume the suspended evaluation of genContext using abruptCompletion as the result of the operation that
132 // suspended it. Let result be the completion record returned by the resumed computation.
133 // 11.Assert: When we return here, genContext has already been removed from the execution context stack and
134 // methodContext is the currently running execution context.
135 // 12.Return Completion(result).
136 JSHandle<JSObject> result;
137 if (abruptCompletion->GetType() == CompletionRecordType::RETURN) {
138 result = GeneratorHelper::Return(thread, genContext, abruptCompletion->GetValue());
139 } else {
140 result = GeneratorHelper::Throw(thread, genContext, abruptCompletion->GetValue());
141 }
142 return result;
143 }
144 } // namespace panda::ecmascript
145