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LibJS: Initialize 'var' bindings to undefined on declaration

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This is what CreateGlobalVarBinding does, so do the same thing in BC.
This commit is contained in:
Ali Mohammad Pur 2022-03-13 12:43:45 +03:30 • committed by Andreas Kling
parent ba9c4959d6
commit 57386ca839
1 changed files with 5 additions and 2 deletions
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7
Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
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@ -176,6 +176,8 @@ Bytecode::CodeGenerationErrorOr<void> ScopeNode::generate_bytecode(Bytecode::Gen
if (!declared_function_names.contains(function_name) && !declared_var_names.contains(function_name)) {
// i. Perform ? env.CreateGlobalVarBinding(F, false).
generator.emit<Bytecode::Op::CreateVariable>(index, Bytecode::Op::EnvironmentMode::Var, false);
generator.emit<Bytecode::Op::LoadImmediate>(js_undefined());
generator.emit<Bytecode::Op::SetVariable>(index, Bytecode::Op::SetVariable::InitializationMode::Initialize, Bytecode::Op::EnvironmentMode::Var);
// ii. Append F to declaredFunctionOrVarNames.
declared_function_names.set(function_name);
@ -848,7 +850,7 @@ Bytecode::CodeGenerationErrorOr<void> FunctionDeclaration::generate_bytecode(Byt
if (m_is_hoisted) {
auto index = generator.intern_identifier(name());
generator.emit<Bytecode::Op::GetVariable>(index);
generator.emit<Bytecode::Op::SetVariable>(index, Bytecode::Op::SetVariable::InitializationMode::Initialize, Bytecode::Op::EnvironmentMode::Var);
generator.emit<Bytecode::Op::SetVariable>(index, Bytecode::Op::SetVariable::InitializationMode::Set, Bytecode::Op::EnvironmentMode::Var);
}
return {};
}
@ -1127,10 +1129,11 @@ Bytecode::CodeGenerationErrorOr<void> VariableDeclaration::generate_bytecode(Byt
generator.emit<Bytecode::Op::LoadImmediate>(js_undefined());
auto initialization_mode = is_lexical_declaration() ? Bytecode::Op::SetVariable::InitializationMode::Initialize : Bytecode::Op::SetVariable::InitializationMode::Set;
auto environment_mode = is_lexical_declaration() ? Bytecode::Op::EnvironmentMode::Lexical : Bytecode::Op::EnvironmentMode::Var;
TRY(declarator.target().visit(
[&](NonnullRefPtr<Identifier> const& id) -> Bytecode::CodeGenerationErrorOr<void> {
generator.emit<Bytecode::Op::SetVariable>(generator.intern_identifier(id->string()), initialization_mode);
generator.emit<Bytecode::Op::SetVariable>(generator.intern_identifier(id->string()), initialization_mode, environment_mode);
return {};
},
[&](NonnullRefPtr<BindingPattern> const& pattern) -> Bytecode::CodeGenerationErrorOr<void> {