[ES6] Modules' export default function/class should be declaration
https://bugs.webkit.org/show_bug.cgi?id=160499
Reviewed by Saam Barati.
JSTests:
Add several module tests. And flip the failed tests flags in test262.
- modules/export-default-function-name-in-assignment-expression.js: Added.
(export.default):
- modules/export-default-function-name-in-class-declaration.js: Added.
- modules/export-default-function-name-in-function-declaration.js: Added.
(export.default):
- modules/export-default-function-name-in-generator-declaration.js: Added.
(export.default):
- stress/method-name.js: Added.
(testSyntax):
(testSyntaxError):
(testSyntaxError.Hello..hello.hello):
(testSyntaxError.Hello):
(SyntaxError.Unexpected.identifier.string_appeared_here.Expected.an.opening.string_appeared_here.before.a.method.testSyntaxError.let.obj.hello.hello):
(testSyntaxError.Hello..get hello):
(testSyntaxError.Hello..set hello):
Source/JavaScriptCore:
Previously, we parsed the following cases as FunctionExpression and ClassExpression.
export default function () { }
export default class { }
But, as per ES6 spec, the above function ... and class ... parts should be parsed
as function declaration and class declaration. This has big difference; the instantiation
of the function declarations are done in the function prologue.
In this , we correctly parse the above cases as declaration. To handle no-named
declarations, we add a new flag, DeclarationDefaultContext. This indicates [Default]
flag in the ES6 spec's BNF.
Furthermore, this also fixes the following name related bugs.
- The bug related to "export default"'s function name. If the name is not provided (like the above case), the name of the function becomes
"default", not "*default*". This is special handling in ES6 spec. We handle this in JSFunction's reifyName.
class Hello { hello hello() { } } is accepted. We introduced FunctionRequirements::Unnamed and fix this bug.
- parser/ModuleScopeData.h:
(JSC::ModuleScopeData::exportBinding):
Exported names are already guranteed uniqueness by m_exportedNames. Not necessary to use set here. Use vector instead.
(JSC::Parser<LexerType>::parseFunctionInfo):
If we pass FunctionRequirements::NoRequirements, we need to initialize functionInfo.name / classInfo.className
with the default fallback name. For example, in the above export default case, we initialize it with *default*.
(JSC::Parser<LexerType>::parseFunctionDeclaration):
(JSC::Parser<LexerType>::parseClassDeclaration):
(JSC::Parser<LexerType>::parseClass):
(JSC::Parser<LexerType>::parseExportDeclaration):
(JSC::Parser<LexerType>::parsePropertyMethod):
(JSC::Parser<LexerType>::parseGetterSetter):
(JSC::Parser<LexerType>::parseClassExpression):
(JSC::Parser<LexerType>::parseFunctionExpression):
(JSC::Parser<LexerType>::parsePrimaryExpression):
(JSC::Parser<LexerType>::parseArrowFunctionExpression):
- parser/Parser.h:
- runtime/JSFunction.cpp:
(JSC::JSFunction::reifyName):
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