[ES6] implement block scoping to enable 'let'
[WebKit-https.git] / Source / JavaScriptCore / builtins / BuiltinExecutables.cpp
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25
26
27 #include "config.h"
28 #include "BuiltinExecutables.h"
29
30 #include "BuiltinNames.h"
31 #include "Executable.h"
32 #include "JSCInlines.h"
33 #include "Parser.h"
34 #include <wtf/NeverDestroyed.h>
35
36 namespace JSC {
37
38 BuiltinExecutables::BuiltinExecutables(VM& vm)
39     : m_vm(vm)
40 #define INITIALIZE_BUILTIN_SOURCE_MEMBERS(name, functionName, length) , m_##name##Source(makeSource(StringImpl::createFromLiteral(s_##name, length)))
41     JSC_FOREACH_BUILTIN(INITIALIZE_BUILTIN_SOURCE_MEMBERS)
42 #undef EXPOSE_BUILTIN_STRINGS
43 {
44 }
45
46 UnlinkedFunctionExecutable* BuiltinExecutables::createDefaultConstructor(ConstructorKind constructorKind, const Identifier& name)
47 {
48     static NeverDestroyed<const String> baseConstructorCode(ASCIILiteral("(function () { })"));
49     static NeverDestroyed<const String> derivedConstructorCode(ASCIILiteral("(function () { super(...arguments); })"));
50
51     switch (constructorKind) {
52     case ConstructorKind::None:
53         break;
54     case ConstructorKind::Base:
55         return createExecutableInternal(makeSource(baseConstructorCode), name, constructorKind);
56     case ConstructorKind::Derived:
57         return createExecutableInternal(makeSource(derivedConstructorCode), name, constructorKind);
58     }
59     ASSERT_NOT_REACHED();
60     return nullptr;
61 }
62
63 UnlinkedFunctionExecutable* BuiltinExecutables::createExecutableInternal(const SourceCode& source, const Identifier& name, ConstructorKind constructorKind)
64 {
65     JSTextPosition positionBeforeLastNewline;
66     ParserError error;
67     bool isParsingDefaultConstructor = constructorKind != ConstructorKind::None;
68     JSParserBuiltinMode builtinMode = isParsingDefaultConstructor ? JSParserBuiltinMode::NotBuiltin : JSParserBuiltinMode::Builtin;
69     UnlinkedFunctionKind kind = isParsingDefaultConstructor ? UnlinkedNormalFunction : UnlinkedBuiltinFunction;
70     RefPtr<SourceProvider> sourceOverride = isParsingDefaultConstructor ? source.provider() : nullptr;
71     std::unique_ptr<ProgramNode> program = parse<ProgramNode>(
72         &m_vm, source, 0, Identifier(), builtinMode, 
73         JSParserStrictMode::NotStrict, 
74         JSParserCodeType::Program,
75         error, &positionBeforeLastNewline, constructorKind);
76
77     if (!program) {
78         dataLog("Fatal error compiling builtin function '", name.string(), "': ", error.message());
79         CRASH();
80     }
81
82     StatementNode* exprStatement = program->singleStatement();
83     RELEASE_ASSERT(exprStatement);
84     RELEASE_ASSERT(exprStatement->isExprStatement());
85     ExpressionNode* funcExpr = static_cast<ExprStatementNode*>(exprStatement)->expr();
86     RELEASE_ASSERT(funcExpr);
87     RELEASE_ASSERT(funcExpr->isFuncExprNode());
88     FunctionBodyNode* body = static_cast<FuncExprNode*>(funcExpr)->body();
89     RELEASE_ASSERT(!program->hasCapturedVariables());
90     
91     body->setEndPosition(positionBeforeLastNewline);
92     RELEASE_ASSERT(body);
93     RELEASE_ASSERT(body->ident().isNull());
94     
95     // This function assumes an input string that would result in a single anonymous function expression.
96     body->setEndPosition(positionBeforeLastNewline);
97     RELEASE_ASSERT(body);
98     for (const auto& closedVariable : program->closedVariables()) {
99         if (closedVariable == m_vm.propertyNames->arguments.impl())
100             continue;
101         
102         if (closedVariable == m_vm.propertyNames->undefinedKeyword.impl())
103             continue;
104     }
105     body->overrideName(name);
106     VariableEnvironment dummyTDZVariables;
107     UnlinkedFunctionExecutable* functionExecutable = UnlinkedFunctionExecutable::create(&m_vm, source, body, kind, dummyTDZVariables, WTF::move(sourceOverride));
108     functionExecutable->m_nameValue.set(m_vm, functionExecutable, jsString(&m_vm, name.string()));
109     return functionExecutable;
110 }
111
112 void BuiltinExecutables::finalize(Handle<Unknown>, void* context)
113 {
114     static_cast<Weak<UnlinkedFunctionExecutable>*>(context)->clear();
115 }
116
117 #define DEFINE_BUILTIN_EXECUTABLES(name, functionName, length) \
118 UnlinkedFunctionExecutable* BuiltinExecutables::name##Executable() \
119 {\
120     if (!m_##name##Executable)\
121         m_##name##Executable = Weak<UnlinkedFunctionExecutable>(createBuiltinExecutable(m_##name##Source, m_vm.propertyNames->builtinNames().functionName##PublicName()), this, &m_##name##Executable);\
122     return m_##name##Executable.get();\
123 }
124 JSC_FOREACH_BUILTIN(DEFINE_BUILTIN_EXECUTABLES)
125 #undef EXPOSE_BUILTIN_SOURCES
126
127 }