1 /*
2  * Copyright (c) 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 "optionalChain.h"
17 
18 #include <compiler/core/pandagen.h>
19 #include <ir/expressions/callExpression.h>
20 
21 namespace panda::es2panda::compiler {
OptionalChain(PandaGen *pg, const ir::AstNode *node)22 OptionalChain::OptionalChain(PandaGen *pg, const ir::AstNode *node) : pg_(pg), node_(node), prev_(pg->optionalChain_)
23 {
24     pg_->optionalChain_ = this;
25 }
26 
~OptionalChain()27 OptionalChain::~OptionalChain()
28 {
29     if (label_) {
30         pg_->SetLabel(node_, label_);
31     }
32     pg_->optionalChain_ = prev_;
33 }
34 
CheckNullish(bool optional, compiler::VReg obj)35 void OptionalChain::CheckNullish(bool optional, compiler::VReg obj)
36 {
37     if (!optional) {
38         return;
39     }
40 
41     if (!label_) {
42         label_ = pg_->AllocLabel();
43     }
44 
45     RegScope rs(pg_);
46 
47     auto *notNullish = pg_->AllocLabel();
48     auto *nullish = pg_->AllocLabel();
49 
50     pg_->LoadConst(node_, Constant::JS_NULL);
51     pg_->Condition(node_, lexer::TokenType::PUNCTUATOR_NOT_STRICT_EQUAL, obj, nullish);
52     pg_->LoadConst(node_, Constant::JS_UNDEFINED);
53     pg_->Condition(node_, lexer::TokenType::PUNCTUATOR_NOT_STRICT_EQUAL, obj, nullish);
54     pg_->Branch(node_, notNullish);
55     pg_->SetLabel(node_, nullish);
56 
57     pg_->LoadConst(node_, compiler::Constant::JS_UNDEFINED);
58     InitThisVRegForCallExpression();
59     pg_->Branch(node_, label_);
60     pg_->SetLabel(node_, notNullish);
61     pg_->LoadAccumulator(node_, obj);
62 }
63 
InitThisVRegForCallExpression()64 void OptionalChain::InitThisVRegForCallExpression()
65 {
66     auto *iter = node_->Parent();
67     while (iter->IsTSNonNullExpression() || iter->IsTSAsExpression() || iter->IsTSTypeAssertion()) {
68         iter = iter->Parent();
69     }
70 
71     if (!iter->IsCallExpression()) {
72         return;
73     }
74 
75     auto callExpr = iter->AsCallExpression();
76     if (callExpr->HasThisVReg()) {
77         pg_->StoreAccumulator(node_, callExpr->GetThisVReg());
78     }
79 }
80 
81 }   // namespace panda::es2panda::compiler
82