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
21namespace panda::es2panda::compiler {
22OptionalChain::OptionalChain(PandaGen *pg, const ir::AstNode *node) : pg_(pg), node_(node), prev_(pg->optionalChain_)
23{
24    pg_->optionalChain_ = this;
25}
26
27OptionalChain::~OptionalChain()
28{
29    if (label_) {
30        pg_->SetLabel(node_, label_);
31    }
32    pg_->optionalChain_ = prev_;
33}
34
35void 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
64void 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