1 /*
2 * Copyright (c) 2021-2022 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 "iterators.h"
17
18 #include <compiler/core/pandagen.h>
19 #include <compiler/base/catchTable.h>
20 #include <compiler/function/functionBuilder.h>
21
22 namespace panda::es2panda::compiler {
23
24 // Iterator
25
Iterator(PandaGen * pg,const ir::AstNode * node,IteratorType type)26 Iterator::Iterator(PandaGen *pg, const ir::AstNode *node, IteratorType type)
27 : pg_(pg), node_(node), closed_(pg->AllocReg()), method_(pg->AllocReg()), iterator_(pg->AllocReg()),
28 nextResult_(pg->AllocReg()), type_(type)
29 {
30 if (type_ == IteratorType::ASYNC) {
31 pg_->GetAsyncIterator(node);
32 } else {
33 pg_->GetIterator(node);
34 }
35
36 pg_->StoreAccumulator(node, iterator_);
37 pg_->LoadObjByName(node_, iterator_, "next");
38 pg_->StoreAccumulator(node_, method_);
39 pg_->StoreConst(node_, closed_, Constant::JS_FALSE);
40 }
41
GetMethod(util::StringView name) const42 void Iterator::GetMethod(util::StringView name) const
43 {
44 pg_->LoadObjByName(node_, iterator_, name);
45 pg_->StoreAccumulator(node_, method_);
46 }
47
CallMethodWithValue() const48 void Iterator::CallMethodWithValue() const
49 {
50 pg_->CallThis(node_, method_, 2);
51 }
52
CallMethod() const53 void Iterator::CallMethod() const
54 {
55 pg_->CallThis(node_, method_, 1);
56 }
57
Next() const58 void Iterator::Next() const
59 {
60 CallMethod();
61
62 if (type_ == IteratorType::ASYNC) {
63 pg_->FuncBuilder()->Await(node_);
64 }
65
66 pg_->StoreAccumulator(node_, nextResult_);
67 pg_->ThrowIfNotObject(node_, nextResult_);
68 }
69
Complete() const70 void Iterator::Complete() const
71 {
72 pg_->LoadObjByName(node_, nextResult_, "done");
73 }
74
Value() const75 void Iterator::Value() const
76 {
77 pg_->LoadObjByName(node_, nextResult_, "value");
78 }
79
Close(bool abruptCompletion) const80 void Iterator::Close(bool abruptCompletion) const
81 {
82 RegScope rs(pg_);
83 VReg completion = pg_->AllocReg();
84 VReg innerResult = pg_->AllocReg();
85 VReg innerException = pg_->AllocReg();
86 Label *noReturn = pg_->AllocLabel();
87
88 pg_->StoreAccumulator(node_, completion);
89 pg_->LoadAccumulator(node_, closed_);
90 pg_->BranchIfTrue(node_, noReturn);
91
92 pg_->StoreConst(node_, closed_, Constant::JS_TRUE);
93 pg_->StoreConst(node_, innerResult, Constant::JS_UNDEFINED);
94 pg_->StoreConst(node_, innerException, Constant::JS_HOLE);
95
96 TryContext tryCtx(pg_);
97 const auto &labelSet = tryCtx.LabelSet();
98
99 pg_->SetLabel(node_, labelSet.TryBegin());
100
101 // 4. Let innerResult be GetMethod(iterator, "return").
102 GetMethod("return");
103
104 // 5. If innerResult.[[Type]] is normal, then
105 {
106 // a. Let return be innerResult.[[Value]].
107 // b. If return is undefined, return Completion(completion).
108 pg_->BranchIfUndefined(node_, noReturn);
109 // c. Set innerResult to Call(return, iterator).
110 CallMethod();
111 if (type_ == IteratorType::ASYNC) {
112 // d. If innerResult.[[Type]] is normal, set innerResult to Await(innerResult.[[Value]]).
113 pg_->FuncBuilder()->Await(node_);
114 }
115 pg_->StoreAccumulator(node_, innerResult);
116 }
117
118 pg_->SetLabel(node_, labelSet.TryEnd());
119 pg_->Branch(node_, labelSet.CatchEnd());
120
121 pg_->SetLabel(node_, labelSet.CatchBegin());
122 pg_->StoreAccumulator(node_, innerException);
123 pg_->SetLabel(node_, labelSet.CatchEnd());
124
125 // 6. If completion.[[Type]] is throw, return Completion(completion).
126 if (abruptCompletion) {
127 pg_->LoadAccumulator(node_, completion);
128 pg_->EmitThrow(node_);
129 } else {
130 // 7. If innerResult.[[Type]] is throw, return Completion(innerResult).
131 pg_->LoadAccumulator(node_, innerException);
132 pg_->EmitRethrow(node_);
133 }
134
135 // 8. If Type(innerResult.[[Value]]) is not Object, throw a TypeError exception.
136 pg_->LoadAccumulator(node_, innerResult);
137 pg_->ThrowIfNotObject(node_, innerResult);
138
139 pg_->SetLabel(node_, noReturn);
140 pg_->LoadAccumulator(node_, completion);
141 if (abruptCompletion) {
142 pg_->EmitThrow(node_);
143 }
144 }
145
DestructuringIterator(PandaGen * pg,const ir::AstNode * node)146 DestructuringIterator::DestructuringIterator(PandaGen *pg, const ir::AstNode *node)
147 : Iterator(pg, node, IteratorType::SYNC), done_(pg->AllocReg()), result_(pg->AllocReg())
148 {
149 pg_->StoreConst(node, done_, Constant::JS_FALSE);
150 pg_->StoreConst(node, result_, Constant::JS_UNDEFINED);
151 }
152
Step(Label * doneTarget) const153 void DestructuringIterator::Step(Label *doneTarget) const
154 {
155 TryContext tryCtx(pg_);
156 const auto &labelSet = tryCtx.LabelSet();
157 Label *normalClose = pg_->AllocLabel();
158 Label *noClose = pg_->AllocLabel();
159
160 pg_->SetLabel(node_, labelSet.TryBegin());
161 Next();
162 Complete();
163 pg_->StoreAccumulator(node_, done_);
164 pg_->BranchIfFalse(node_, normalClose);
165 pg_->StoreConst(node_, done_, Constant::JS_TRUE);
166 pg_->LoadConst(node_, Constant::JS_UNDEFINED);
167 OnIterDone(doneTarget);
168 pg_->Branch(node_, noClose);
169
170 pg_->SetLabel(node_, normalClose);
171 Value();
172 pg_->StoreAccumulator(node_, result_);
173 pg_->SetLabel(node_, noClose);
174
175 pg_->SetLabel(node_, labelSet.TryEnd());
176 pg_->Branch(node_, labelSet.CatchEnd());
177
178 pg_->SetLabel(node_, labelSet.CatchBegin());
179 pg_->StoreAccumulator(node_, result_);
180 pg_->StoreConst(node_, done_, Constant::JS_TRUE);
181 pg_->LoadAccumulator(node_, result_);
182 pg_->EmitThrow(node_);
183 pg_->SetLabel(node_, labelSet.CatchEnd());
184 }
185
OnIterDone(Label * doneTarget) const186 void DestructuringIterator::OnIterDone([[maybe_unused]] Label *doneTarget) const
187 {
188 pg_->LoadConst(node_, Constant::JS_UNDEFINED);
189 }
190
OnIterDone(Label * doneTarget) const191 void DestructuringRestIterator::OnIterDone([[maybe_unused]] Label *doneTarget) const
192 {
193 pg_->Branch(node_, doneTarget);
194 }
195
196 } // namespace panda::es2panda::compiler
197