1 /**
2  * Copyright (c) 2021 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 "hoisting.h"
17 
18 #include <binder/binder.h>
19 #include <binder/scope.h>
20 #include <compiler/core/pandagen.h>
21 #include <ir/base/scriptFunction.h>
22 #include <ir/statements/variableDeclaration.h>
23 #include <parser/module/sourceTextModuleRecord.h>
24 
25 namespace panda::es2panda::compiler {
26 
StoreModuleVarOrLocalVar(PandaGen *pg, binder::ScopeFindResult &result, const binder::Decl *decl)27 static void StoreModuleVarOrLocalVar(PandaGen *pg, binder::ScopeFindResult &result, const binder::Decl *decl)
28 {
29     if (decl->IsImportOrExportDecl()) {
30         ASSERT(pg->Scope()->IsModuleScope());
31         auto *var = pg->Scope()->FindLocal(decl->Name());
32         CHECK_NOT_NULL(var);
33         ASSERT(var->IsModuleVariable());
34         pg->StoreModuleVariable(decl->Node(), var->AsModuleVariable());
35     } else {
36         pg->StoreAccToLexEnv(decl->Node(), result, true);
37     }
38 }
39 
HoistVar(PandaGen *pg, binder::Variable *var, const binder::VarDecl *decl)40 static void HoistVar(PandaGen *pg, binder::Variable *var, const binder::VarDecl *decl)
41 {
42     if (decl->IsDeclare()) {
43         return;
44     }
45 
46     auto *scope = pg->Scope();
47     if (scope->IsGlobalScope()) {
48         pg->LoadConst(decl->Node(), Constant::JS_UNDEFINED);
49         pg->StoreGlobalVar(decl->Node(), decl->Name());
50         return;
51     }
52 
53     auto *funcScope = scope->EnclosingFunctionVariableScope();
54     CHECK_NOT_NULL(funcScope);
55     if (scope->HasParamScope() && funcScope->ParamScope()->HasParam(decl->Name())) {
56         return;
57     }
58 
59     binder::ScopeFindResult result(decl->Name(), scope, 0, var);
60 
61     pg->LoadConst(decl->Node(), Constant::JS_UNDEFINED);
62     StoreModuleVarOrLocalVar(pg, result, decl);
63 }
64 
HoistFunction(PandaGen *pg, binder::Variable *var, const binder::FunctionDecl *decl)65 static void HoistFunction(PandaGen *pg, binder::Variable *var, const binder::FunctionDecl *decl)
66 {
67     const ir::ScriptFunction *scriptFunction = decl->Node()->AsScriptFunction();
68     if (scriptFunction->Declare()) {
69         return;
70     }
71 
72     const auto &internalName = scriptFunction->Scope()->InternalName();
73     auto *scope = pg->Scope();
74     if (scope->IsGlobalScope()) {
75         pg->DefineFunction(decl->Node(), scriptFunction, internalName);
76         pg->StoreGlobalVar(decl->Node(), var->Declaration()->Name());
77         return;
78     }
79 
80     ASSERT(scope->IsFunctionScope() || scope->IsCatchScope() || scope->IsLocalScope() ||
81            scope->IsModuleScope() || scope->IsTSModuleScope() || scope->IsTSEnumScope() ||
82            scope->IsStaticBlockScope());
83     binder::ScopeFindResult result(decl->Name(), scope, 0, var);
84 
85     pg->DefineFunction(decl->Node(), scriptFunction, internalName);
86     StoreModuleVarOrLocalVar(pg, result, decl);
87 }
88 
HoistNameSpaceImports(PandaGen *pg)89 static void HoistNameSpaceImports(PandaGen *pg)
90 {
91     if (pg->Scope()->IsModuleScope()) {
92         parser::SourceTextModuleRecord *moduleRecord = pg->Binder()->Program()->ModuleRecord();
93         ASSERT(moduleRecord != nullptr);
94         for (auto nameSpaceEntry : moduleRecord->GetNamespaceImportEntries()) {
95             auto *var = pg->TopScope()->FindLocal(nameSpaceEntry->localName_);
96             CHECK_NOT_NULL(var);
97             auto *node = var->Declaration()->Node();
98             CHECK_NOT_NULL(node);
99             pg->GetModuleNamespace(node, nameSpaceEntry->moduleRequestIdx_);
100             pg->StoreVar(node, {nameSpaceEntry->localName_, pg->TopScope(), 0, var}, true);
101         }
102     }
103 }
104 
Hoist(PandaGen *pg)105 void Hoisting::Hoist(PandaGen *pg)
106 {
107     const auto *scope = pg->Scope();
108 
109     for (const auto &[_, var] : scope->Bindings()) {
110         (void)_;
111         if (!var->HasFlag(binder::VariableFlags::HOIST)) {
112             continue;
113         }
114 
115         const auto *decl = var->Declaration();
116 
117         if (decl->IsVarDecl()) {
118             HoistVar(pg, var, decl->AsVarDecl());
119         } else {
120             ASSERT(decl->IsFunctionDecl());
121             HoistFunction(pg, var, decl->AsFunctionDecl());
122         }
123     }
124 
125     HoistNameSpaceImports(pg);
126 }
127 
128 }  // namespace panda::es2panda::compiler
129