1 /**
2  * Copyright (c) 2023-2024 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 "util.h"
17 
18 #include "compiler/lowering/scopesInit/scopesInitPhase.h"
19 #include "ir/expressions/identifier.h"
20 
21 namespace ark::es2panda::compiler {
22 
NearestScope(const ir::AstNode *ast)23 varbinder::Scope *NearestScope(const ir::AstNode *ast)
24 {
25     while (ast != nullptr && !ast->IsScopeBearer()) {
26         ast = ast->Parent();
27     }
28 
29     return ast == nullptr ? nullptr : ast->Scope();
30 }
31 
ContainingClass(const ir::AstNode *ast)32 checker::ETSObjectType const *ContainingClass(const ir::AstNode *ast)
33 {
34     while (ast != nullptr && !ast->IsClassDefinition()) {
35         ast = ast->Parent();
36     }
37 
38     return ast == nullptr ? nullptr : ast->AsClassDefinition()->TsType()->AsETSObjectType();
39 }
40 
Gensym(ArenaAllocator *const allocator)41 ir::Identifier *Gensym(ArenaAllocator *const allocator)
42 {
43     util::UString const s = GenName(allocator);
44     return allocator->New<ir::Identifier>(s.View(), allocator);
45 }
46 
GenName(ArenaAllocator *const allocator)47 util::UString GenName(ArenaAllocator *const allocator)
48 {
49     static std::string const GENSYM_CORE = "gensym$_";
50     static std::size_t gensymCounter = 0U;
51 
52     return util::UString {GENSYM_CORE + std::to_string(++gensymCounter), allocator};
53 }
54 
55 // Function to clear expression node types and identifier node variables (for correct re-binding and re-checking)
56 void ClearTypesVariablesAndScopes(ir::AstNode *node) noexcept
57 {
58     auto doNode = [](ir::AstNode *nn) {
59         if (nn->IsScopeBearer()) {
60             nn->ClearScope();
61         }
62         if (nn->IsTyped() && !(nn->IsExpression() && nn->AsExpression()->IsTypeNode())) {
63             nn->AsTyped()->SetTsType(nullptr);
64         }
65         if (nn->IsIdentifier()) {
66             nn->AsIdentifier()->SetVariable(nullptr);
67         }
68     };
69 
70     doNode(node);
71     node->Iterate([doNode](ir::AstNode *child) -> void {
72         doNode(child);
73         ClearTypesVariablesAndScopes(child);
74     });
75 }
76 
77 ArenaSet<varbinder::Variable *> FindCaptured(ArenaAllocator *allocator, ir::AstNode *scopeBearer) noexcept
78 {
79     auto result = ArenaSet<varbinder::Variable *> {allocator->Adapter()};
80     auto scopes = ArenaSet<varbinder::Scope *> {allocator->Adapter()};
81     scopeBearer->IterateRecursivelyPreorder([&result, &scopes](ir::AstNode *ast) {
82         if (ast->IsScopeBearer() && ast->Scope() != nullptr) {
83             scopes.insert(ast->Scope());
84             if (ast->Scope()->IsFunctionScope()) {
85                 scopes.insert(ast->Scope()->AsFunctionScope()->ParamScope());
86             } else if (ast->IsForUpdateStatement() || ast->IsForInStatement() || ast->IsForOfStatement() ||
87                        ast->IsCatchClause()) {
88                 // NOTE(gogabr) LoopScope _does not_ currently respond to IsLoopScope().
89                 // For now, this is the way to reach LoopDeclarationScope.
90                 scopes.insert(ast->Scope()->Parent());
91             }
92         }
93         if (ast->IsIdentifier()) {
94             auto *var = ast->AsIdentifier()->Variable();
95             if (var == nullptr || !var->HasFlag(varbinder::VariableFlags::LOCAL)) {
96                 return;
97             }
98             auto *sc = var->GetScope();
99             if (sc != nullptr && !sc->IsClassScope() && !sc->IsGlobalScope() && scopes.count(var->GetScope()) == 0) {
100                 result.insert(var);
101             }
102         }
103     });
104     return result;
105 }
106 
107 // Rerun varbinder and checker on the node.
Recheck(varbinder::ETSBinder *varBinder, checker::ETSChecker *checker, ir::AstNode *node)108 void Recheck(varbinder::ETSBinder *varBinder, checker::ETSChecker *checker, ir::AstNode *node)
109 {
110     auto *scope = NearestScope(node);
111     auto bscope = varbinder::LexicalScope<varbinder::Scope>::Enter(varBinder, scope);
112 
113     ClearTypesVariablesAndScopes(node);
114     InitScopesPhaseETS::RunExternalNode(node, varBinder);
115     varBinder->ResolveReferencesForScopeWithContext(node, scope);
116 
117     auto *containingClass = ContainingClass(node);
118     // NOTE(gogabr: should determine checker status more finely.
119     auto checkerCtx = checker::SavedCheckerContext(
120         checker, (containingClass == nullptr) ? checker::CheckerStatus::NO_OPTS : checker::CheckerStatus::IN_CLASS,
121         containingClass);
122     auto scopeCtx = checker::ScopeContext(checker, scope);
123 
124     node->Check(checker);
125 }
126 
127 }  // namespace ark::es2panda::compiler
128