Support extends and super keywords
https://bugs.webkit.org/show_bug.cgi?id=142200
Reviewed by Filip Pizlo.
Source/JavaScriptCore:
Added the support for ES6 class syntax inheritance.
Added ConstructorKind as well as boolean flags indicating the constructor kind to
various classes in UnlinkedCodeBlock as well as AST nodes.
Each method stores the associated class as its homeObjectPrivateName. This value is used to
make super calls.
* bytecode/UnlinkedCodeBlock.cpp:
(JSC::generateFunctionCodeBlock):
(JSC::UnlinkedFunctionExecutable::UnlinkedFunctionExecutable):
(JSC::UnlinkedCodeBlock::UnlinkedCodeBlock):
* bytecode/UnlinkedCodeBlock.h:
(JSC::ExecutableInfo::ExecutableInfo):
(JSC::UnlinkedFunctionExecutable::constructorKindIsDerived): Added.
(JSC::UnlinkedCodeBlock::constructorKindIsDerived): Added.
* bytecompiler/BytecodeGenerator.cpp:
(JSC::BytecodeGenerator::BytecodeGenerator): Don't emit op_create_this in a derived class
as the object is allocated by the highest base class's constructor. Also set "this" to null
and store the original value in m_newTargetRegister. "this" is supposed to be in TDZ but
that will be implemented in a separate patch.
(JSC::BytecodeGenerator::emitReturn): Allow "undefined" to be returned from a derived class.
In a derived class's constructor, not returning "undefined" or an object results in a type
error instead of "this" being returned.
(JSC::BytecodeGenerator::emitThrowTypeError): Added.
* bytecompiler/BytecodeGenerator.h:
(JSC::BytecodeGenerator::constructorKindIsDerived): Added.
(JSC::BytecodeGenerator::newTarget): Added.
* bytecompiler/NodesCodegen.cpp:
(JSC::SuperNode::emitBytecode): Added. Emits the code to obtain the callee's parent class.
(JSC::emitSuperBaseForCallee): Added. Emits the code to obtain the parent class's prototype.
(JSC::emitPutHomeObject): Added.
(JSC::PropertyListNode::emitBytecode): Stores the home object when adding methods.
(JSC::PropertyListNode::emitPutConstantProperty): Ditto.
(JSC::BracketAccessorNode::emitBytecode): Added the support for super['foo'].
(JSC::DotAccessorNode::emitBytecode): Added the support for super.foo.
(JSC::FunctionCallValueNode::emitBytecode): Added the support for super().
(JSC::FunctionCallBracketNode::emitBytecode): Added the support for super['foo']().
(JSC::FunctionCallDotNode::emitBytecode): Added the support for super.foo().
(JSC::DeleteBracketNode::emitBytecode): Forbid "delete super.foo".
(JSC::DeleteDotNode::emitBytecode): Forbid "delete super['foo']".
(JSC::ClassExprNode::emitBytecode): Added the support for "classHeritage". This is the main
logic for inheritance. When a class B inherits from a class A, set B.__proto__ to A and set
B.prototype.__proto__ to A.prototype. Throw exceptions when either A or A.__proto__ is not
an object.
* parser/ASTBuilder.h:
(JSC::ASTBuilder::superExpr): Added.
* parser/NodeConstructors.h:
(JSC::SuperNode::SuperNode): Added.
* parser/Nodes.cpp:
(JSC::FunctionBodyNode::FunctionBodyNode):
* parser/Nodes.h:
(JSC::ExpressionNode::isSuperNode):
(JSC::PropertyNode::type):
(JSC::PropertyNode::needsSuperBinding):
* parser/Parser.cpp:
(JSC::Parser<LexerType>::parseFunctionBody):
(JSC::Parser<LexerType>::parseFunctionInfo): Throw a parser error if super() is used outside
of class constructors.
(JSC::Parser<LexerType>::parseFunctionDeclaration):
(JSC::Parser<LexerType>::parseClass): ConstructorKind is "derived" if and only if the parent
class is specified in the declaration / expression.
(JSC::Parser<LexerType>::parseGetterSetter):
(JSC::Parser<LexerType>::parsePrimaryExpression):
(JSC::Parser<LexerType>::parseMemberExpression): Added the support for "super()", "super.foo",
and "super['foo']". Throw a semantic error if "super" appears by itself.
* parser/Parser.h:
(JSC::Scope::Scope): Added m_hasDirectSuper. This variable keeps track of the use of "super()"
so that parseFunctionInfo can spit an error if it's used outside of class constructors.
(JSC::Scope::hasDirectSuper): Added.
(JSC::Scope::setHasDirectSuper): Added.
* parser/ParserModes.h:
(JSC::ConstructorKind): Added.
* parser/SyntaxChecker.h:
(JSC::SyntaxChecker::superExpr): Added.
* runtime/CommonIdentifiers.h: Added homeObjectPrivateName.
* runtime/Executable.h:
(JSC::EvalExecutable::executableInfo):
(JSC::ProgramExecutable::executableInfo):
LayoutTests:
Added tests for "extends" and "super" keywords.
* TestExpectations:
* js/class-syntax-extends-expected.txt: Added.
* js/class-syntax-extends.html: Added.
* js/class-syntax-super-expected.txt: Added.
* js/class-syntax-super.html: Added.
* js/script-tests/class-syntax-extends.js: Added.
* js/script-tests/class-syntax-super.js: Added.
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@181293 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/parser/ParserModes.h b/Source/JavaScriptCore/parser/ParserModes.h
index 0611b88..e209748 100644
--- a/Source/JavaScriptCore/parser/ParserModes.h
+++ b/Source/JavaScriptCore/parser/ParserModes.h
@@ -34,6 +34,9 @@
enum JSParserStrictness { JSParseNormal, JSParseBuiltin, JSParseStrict };
enum JSParserMode { JSParseProgramCode, JSParseFunctionCode };
+enum class ConstructorKind { Base, Derived };
+enum class SuperBinding { Needed, NotNeeded };
+
enum ProfilerMode { ProfilerOff, ProfilerOn };
enum DebuggerMode { DebuggerOff, DebuggerOn };
