Changeset 179371 in webkit for trunk/Source/JavaScriptCore/parser/ASTBuilder.h

Timestamp:

Jan 29, 2015, 2:59:19 PM (10 years ago)

Author:

[email protected]

Message:

Implement ES6 class syntax without inheritance support
​https://bugs.webkit.org/show_bug.cgi?id=140918

Reviewed by Geoffrey Garen.

Source/JavaScriptCore:

Added the most basic support for ES6 class syntax. After this patch, we support basic class definition like:
class A {

constructor() { }
someMethod() { }

}

We'll add the support for "extends" keyword and automatically generating a constructor in follow up patches.
We also don't support block scoping of a class declaration.

We support both class declaration and class expression. A class expression is implemented by the newly added
ClassExprNode AST node. A class declaration is implemented by ClassDeclNode, which is a thin wrapper around
AssignResolveNode.

Tests: js/class-syntax-declaration.html

js/class-syntax-expression.html

• bytecompiler/NodesCodegen.cpp:

(JSC::ObjectLiteralNode::emitBytecode): Create a new object instead of delegating the work to PropertyListNode.
Also fixed the 5-space indentation.
(JSC::PropertyListNode::emitBytecode): Don't create a new object now that ObjectLiteralNode does this.
(JSC::ClassDeclNode::emitBytecode): Added. Just let the AssignResolveNode node emit the byte code.
(JSC::ClassExprNode::emitBytecode): Create the class constructor and add static methods to the constructor by
emitting the byte code for PropertyListNode. Add instance methods to the class's prototype object the same way.

• parser/ASTBuilder.h:

(JSC::ASTBuilder::createClassExpr): Added. Creates a ClassExprNode.
(JSC::ASTBuilder::createClassDeclStatement): Added. Creates a AssignResolveNode and wraps it by a ClassDeclNode.

• parser/NodeConstructors.h:

(JSC::ClassDeclNode::ClassDeclNode): Added.
(JSC::ClassExprNode::ClassExprNode): Added.

• parser/Nodes.h:

(JSC::ClassExprNode): Added.
(JSC::ClassDeclNode): Added.

• parser/Parser.cpp:

(JSC::Parser<LexerType>::parseStatement): Added the support for class declaration.
(JSC::stringForFunctionMode): Return "method" for MethodMode.
(JSC::Parser<LexerType>::parseClassDeclaration): Added. Uses parseClass to create a class expression and wraps
it with ClassDeclNode as described above.
(JSC::Parser<LexerType>::parseClass): Parses a class expression.
(JSC::Parser<LexerType>::parseProperty):
(JSC::Parser<LexerType>::parseGetterSetter): Extracted from parseProperty to share the code between parseProperty
and parseClass.
(JSC::Parser<LexerType>::parsePrimaryExpression): Added the support for class expression.

• parser/Parser.h:

(FunctionParseMode): Added MethodMode.

• parser/SyntaxChecker.h:

(JSC::SyntaxChecker::createClassExpr): Added.
(JSC::SyntaxChecker::createClassDeclStatement): Added.

LayoutTests:

Added two tests for class declarations and class expressions.

• TestExpectations:
• js/class-syntax-declaration-expected.txt: Added.
• js/class-syntax-declaration.html: Added.
• js/class-syntax-expression-expected.txt: Added.
• js/class-syntax-expression.html: Added.
• js/script-tests/class-syntax-declaration.js: Added.
• js/script-tests/class-syntax-expression.js: Added.

File:

• trunk/Source/JavaScriptCore/parser/ASTBuilder.h (modified) (3 diffs)

trunk/Source/JavaScriptCore/parser/ASTBuilder.h

@@ -105 +105 @@
     typedef ParameterNode* FormalParameterList;
     typedef FunctionBodyNode* FunctionBody;
+#if ENABLE(ES6_CLASS_SYNTAX)
+    typedef ClassExprNode* ClassExpression;
+#endif
     typedef StatementNode* Statement;
     typedef ClauseListNode* ClauseList;
@@ -274 +277 @@
     }
 
+#if ENABLE(ES6_CLASS_SYNTAX)
+    ClassExprNode* createClassExpr(const JSTokenLocation& location, const Identifier& name, ExpressionNode* constructor,
+        ExpressionNode* parentClass, PropertyListNode* instanceMethods, PropertyListNode* staticMethods)
+    {
+        return new (m_parserArena) ClassExprNode(location, name, constructor, parentClass, instanceMethods, staticMethods);
+    }
+#endif
+
     ExpressionNode* createFunctionExpr(const JSTokenLocation& location, const ParserFunctionInfo<ASTBuilder>& info, unsigned functionKeywordStart)
     {
@@ -353 +364 @@
         return decl;
     }
+
+#if ENABLE(ES6_CLASS_SYNTAX)
+    StatementNode* createClassDeclStatement(const JSTokenLocation& location, ClassExprNode* classExpression,
+        const JSTextPosition& classStart, const JSTextPosition& classEnd, unsigned startLine, unsigned endLine)
+    {
+        // FIXME: Use "let" declaration.
+        ExpressionNode* assign = createAssignResolve(location, classExpression->name(), classExpression, classStart, classStart + 1, classEnd);
+        ClassDeclNode* decl = new (m_parserArena) ClassDeclNode(location, assign);
+        decl->setLoc(startLine, endLine, location.startOffset, location.lineStartOffset);
+        return decl;
+    }
+#endif
 
     StatementNode* createBlockStatement(const JSTokenLocation& location, JSC::SourceElements* elements, int startLine, int endLine)