Changeset 198332 in webkit for trunk/Source/JavaScriptCore/parser/SyntaxChecker.h

Timestamp:

Mar 17, 2016, 7:58:57 AM (9 years ago)

Author:

[email protected]

Message:

Method names should not appear in the lexical scope of the method's body.
​https://bugs.webkit.org/show_bug.cgi?id=155568

Reviewed by Saam Barati.

Source/JavaScriptCore:

Consider this scenario:

var f = "foo";
var result = ({

f() {

return f; f should be the string "foo", not this method f.

}

}).f();
result === "foo"; Should be true.

The reason this is not current working is because the parser does not yet
distinguish between FunctionExpressions and MethodDefinitions. The ES6 spec
explicitly distinguishes between the 2, and we should do the same.

This patch changes all methods (and getters and setters which are also methods)
to have a FunctionMode of MethodDefinition (instead of FunctionExpression).
functionNameIsInScope() is responsible for determining whether a function's name
should be in its scope or not. It already returns false for any function
whose FunctionMode is not FunctionExpression. Giving methods the MethodDefinition
FunctionMode gets us the correct behavior ES6 expects.

• bytecode/UnlinkedFunctionExecutable.cpp:

(JSC::UnlinkedFunctionExecutable::UnlinkedFunctionExecutable):

• bytecode/UnlinkedFunctionExecutable.h:
• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::emitNewArrowFunctionExpression):
(JSC::BytecodeGenerator::emitNewMethodDefinition):

• bytecompiler/BytecodeGenerator.h:
• bytecompiler/NodesCodegen.cpp:

(JSC::ArrowFuncExprNode::emitBytecode):
(JSC::MethodDefinitionNode::emitBytecode):
(JSC::YieldExprNode::emitBytecode):

• parser/ASTBuilder.h:

(JSC::ASTBuilder::createFunctionExpr):
(JSC::ASTBuilder::createMethodDefinition):
(JSC::ASTBuilder::createFunctionMetadata):
(JSC::ASTBuilder::createGetterOrSetterProperty):
(JSC::ASTBuilder::createArguments):

• parser/NodeConstructors.h:

(JSC::FunctionParameters::FunctionParameters):
(JSC::BaseFuncExprNode::BaseFuncExprNode):
(JSC::FuncExprNode::FuncExprNode):
(JSC::FuncDeclNode::FuncDeclNode):
(JSC::ArrowFuncExprNode::ArrowFuncExprNode):
(JSC::MethodDefinitionNode::MethodDefinitionNode):
(JSC::YieldExprNode::YieldExprNode):

• parser/Nodes.h:

(JSC::BaseFuncExprNode::metadata):

• parser/Parser.cpp:

(JSC::Parser<LexerType>::parseClass):
(JSC::Parser<LexerType>::parsePropertyMethod):

• parser/ParserModes.h:
• parser/SyntaxChecker.h:

(JSC::SyntaxChecker::createFunctionExpr):
(JSC::SyntaxChecker::createFunctionMetadata):
(JSC::SyntaxChecker::createArrowFunctionExpr):
(JSC::SyntaxChecker::createMethodDefinition):
(JSC::SyntaxChecker::setFunctionNameStart):
(JSC::SyntaxChecker::createArguments):

• tests/es6.yaml:

LayoutTests:

• inspector/model/scope-chain-node-expected.txt:
• rebased expected result.

• js/script-tests/function-toString-vs-name.js:
• fixed a bug in the shouldBe() function.

• js/methods-names-should-not-be-in-lexical-scope-expected.txt: Added.
• js/methods-names-should-not-be-in-lexical-scope.html: Added.
• js/script-tests/methods-names-should-not-be-in-lexical-scope.js: Added.
• test all variations of methods.

File:

• trunk/Source/JavaScriptCore/parser/SyntaxChecker.h (modified) (1 diff)

trunk/Source/JavaScriptCore/parser/SyntaxChecker.h

@@ -187 +187 @@
     int createFunctionMetadata(const JSTokenLocation&, const JSTokenLocation&, int, int, bool, int, int, int, ConstructorKind, SuperBinding, unsigned, SourceParseMode, bool, InnerArrowFunctionCodeFeatures = NoInnerArrowFunctionFeatures) { return FunctionBodyResult; }
     ExpressionType createArrowFunctionExpr(const JSTokenLocation&, const ParserFunctionInfo<SyntaxChecker>&) { return FunctionExpr; }
+    ExpressionType createMethodDefinition(const JSTokenLocation&, const ParserFunctionInfo<SyntaxChecker>&) { return FunctionExpr; }
     void setFunctionNameStart(int, int) { }
     int createArguments() { return ArgumentsResult; }