Changeset 203953 in webkit for trunk/Source/JavaScriptCore/parser/ModuleScopeData.h

Timestamp:

Jul 31, 2016, 12:04:57 AM (9 years ago)

Author:

Yusuke Suzuki

Message:

[ES6] Module binding can be exported by multiple names
​https://bugs.webkit.org/show_bug.cgi?id=160343

Reviewed by Saam Barati.

ES6 Module can export the same local binding by using multiple names.
For example,

`
var value = 42;

export { value };
export { value as value2 };
`

Currently, we only allowed one local binding to be exported with one name. So, in the above case,
the local binding "value" is exported as "value2" and "value" name is not exported. This is wrong.

To fix this issue, we collect the correspondence (local name => exported name) to the local bindings
in the parser. Previously, we only maintained the exported local bindings in the parser. And utilize
this information when creating the export entries in ModuleAnalyzer.

And this patch also moves ModuleScopeData from the Scope object to the Parser class since exported
names should be managed per-module, not per-scope.

This change fixes several test262 failures.

• JavaScriptCore.xcodeproj/project.pbxproj:
• parser/ModuleAnalyzer.cpp:

(JSC::ModuleAnalyzer::exportVariable):
(JSC::ModuleAnalyzer::analyze):
(JSC::ModuleAnalyzer::exportedBinding): Deleted.
(JSC::ModuleAnalyzer::declareExportAlias): Deleted.

• parser/ModuleAnalyzer.h:
• parser/ModuleScopeData.h: Copied from Source/JavaScriptCore/parser/ModuleAnalyzer.h.

(JSC::ModuleScopeData::create):
(JSC::ModuleScopeData::exportedBindings):
(JSC::ModuleScopeData::exportName):
(JSC::ModuleScopeData::exportBinding):

• parser/Nodes.cpp:

(JSC::ProgramNode::ProgramNode):
(JSC::ModuleProgramNode::ModuleProgramNode):
(JSC::EvalNode::EvalNode):
(JSC::FunctionNode::FunctionNode):

• parser/Nodes.h:

(JSC::ModuleProgramNode::moduleScopeData):

• parser/NodesAnalyzeModule.cpp:

(JSC::ExportDefaultDeclarationNode::analyzeModule):
(JSC::ExportNamedDeclarationNode::analyzeModule): Deleted.

• parser/Parser.cpp:

(JSC::Parser<LexerType>::Parser):
(JSC::Parser<LexerType>::parseModuleSourceElements):
(JSC::Parser<LexerType>::parseVariableDeclarationList):
(JSC::Parser<LexerType>::createBindingPattern):
(JSC::Parser<LexerType>::parseFunctionDeclaration):
(JSC::Parser<LexerType>::parseClassDeclaration):
(JSC::Parser<LexerType>::parseExportSpecifier):
(JSC::Parser<LexerType>::parseExportDeclaration):

• parser/Parser.h:

(JSC::Parser::exportName):
(JSC::Parser<LexerType>::parse):
(JSC::ModuleScopeData::create): Deleted.
(JSC::ModuleScopeData::exportedBindings): Deleted.
(JSC::ModuleScopeData::exportName): Deleted.
(JSC::ModuleScopeData::exportBinding): Deleted.
(JSC::Scope::Scope): Deleted.
(JSC::Scope::setSourceParseMode): Deleted.
(JSC::Scope::moduleScopeData): Deleted.
(JSC::Scope::setIsModule): Deleted.

• tests/modules/aliased-names.js: Added.
• tests/modules/aliased-names/main.js: Added.

(change):

• tests/stress/modules-syntax-error-with-names.js:

(export.Cocoa):
(SyntaxError.Cannot.export.a.duplicate.name):

• tests/test262.yaml:

File:

• trunk/Source/JavaScriptCore/parser/ModuleScopeData.h (copied) (copied from trunk/Source/JavaScriptCore/parser/ModuleAnalyzer.h ) (2 diffs)

trunk/Source/JavaScriptCore/parser/ModuleScopeData.h

@@ -1 +1 @@
 /*
  * Copyright (C) 2015 Apple Inc. All rights reserved.
+ * Copyright (C) 2016 Yusuke Suzuki <[email protected]>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -24 +25 @@
  */
 
-#ifndef ModuleAnalyzer_h
-#define ModuleAnalyzer_h
+#pragma once
 
-#include "Nodes.h"
+#include "Identifier.h"
+#include <wtf/RefPtr.h>
 
 namespace JSC {
 
-class JSModuleRecord;
-class SourceCode;
+class ModuleScopeData : public RefCounted<ModuleScopeData> {
+WTF_MAKE_NONCOPYABLE(ModuleScopeData);
+WTF_MAKE_FAST_ALLOCATED;
+public:
+    typedef HashMap<RefPtr<UniquedStringImpl>, IdentifierSet, IdentifierRepHash, HashTraits<RefPtr<UniquedStringImpl>>> IdentifierAliasMap;
 
-class ModuleAnalyzer {
-    WTF_MAKE_NONCOPYABLE(ModuleAnalyzer);
-public:
-    ModuleAnalyzer(ExecState*, const Identifier& moduleKey, const SourceCode&, const VariableEnvironment& declaredVariables, const VariableEnvironment& lexicalVariables);
+    static Ref<ModuleScopeData> create() { return adoptRef(*new ModuleScopeData); }
 
-    JSModuleRecord* analyze(ModuleProgramNode&);
+    const IdentifierAliasMap& exportedBindings() const { return m_exportedBindings; }
 
-    VM& vm() { return *m_vm; }
+    bool exportName(const Identifier& exportedName)
+    {
+        return m_exportedNames.add(exportedName.impl()).isNewEntry;
+    }
 
-    JSModuleRecord* moduleRecord() { return m_moduleRecord.get(); }
+    void exportBinding(const Identifier& localName, const Identifier& exportedName)
+    {
+        m_exportedBindings.add(localName.impl(), IdentifierSet()).iterator->value.add(exportedName.impl());
+    }
 
-    void declareExportAlias(const Identifier& localName, const Identifier& exportName);
+    void exportBinding(const Identifier& localName)
+    {
+        exportBinding(localName, localName);
+    }
 
 private:
-    typedef HashMap<RefPtr<UniquedStringImpl>, Identifier, IdentifierRepHash, HashTraits<RefPtr<UniquedStringImpl>>> IdentifierAliasMap;
+    ModuleScopeData() = default;
 
-    void exportVariable(const RefPtr<UniquedStringImpl>&, const VariableEnvironmentEntry&);
-
-    Identifier exportedBinding(const RefPtr<UniquedStringImpl>& ident);
-
-    VM* m_vm;
-    Strong<JSModuleRecord> m_moduleRecord;
-    IdentifierAliasMap m_aliasMap;
+    IdentifierSet m_exportedNames { };
+    IdentifierAliasMap m_exportedBindings { };
 };
 
-} // namespace JSC
-
-#endif // ModuleAnalyzer_h
+} // namespace