| Summary: | ES6 classes: When a class extends B, super() invokes B.prototype.constructor() instead of B() | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Product: | WebKit | Reporter: | Claude Pache <claude.pache> | ||||||
| Component: | JavaScriptCore | Assignee: | Yusuke Suzuki <ysuzuki> | ||||||
| Status: | RESOLVED FIXED | ||||||||
| Severity: | Normal | CC: | commit-queue, fpizlo, ggaren, keith_miller, ljharb, mark.lam, msaboff, rniwa, saam, ysuzuki | ||||||
| Priority: | P2 | ||||||||
| Version: | WebKit Nightly Build | ||||||||
| Hardware: | Unspecified | ||||||||
| OS: | Unspecified | ||||||||
| Bug Depends on: | |||||||||
| Bug Blocks: | 140491 | ||||||||
| Attachments: |
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Created attachment 262857 [details]
Patch
Created attachment 262858 [details]
Patch
Comment on attachment 262858 [details]
Patch
r=me
Does the latest spec change the "emitSuperBaseForCallee" static function in BytecodeGenerator?
(In reply to comment #3) > Comment on attachment 262858 [details] > Patch > > r=me > Does the latest spec change the "emitSuperBaseForCallee" static function in > BytecodeGenerator? Yup. emitSuperBaseForCallee is correct in the latest spec :) http://ecma-international.org/ecma-262/6.0/#sec-getsuperbase Comment on attachment 262858 [details] Patch Clearing flags on attachment: 262858 Committed r190847: <http://trac.webkit.org/changeset/190847> All reviewed patches have been landed. Closing bug. |
Testcase: ```js var called = null class B { constructor() { called = 'B' } } class C extends B {} B.prototype.constructor = function F() { called = 'F' } new C called // should be 'B', is 'F' ``` It seems to me that JSC follows an old drafted semantics of `super()`, when it was equivalent to `super.constructor()`. For reference, see the runtime semantics of `SuperCall : super Arguments` in the final spec: http://www.ecma-international.org/ecma-262/6.0/#sec-super-keyword-runtime-semantics-evaluation and pay attention to the definition of GetSuperConstructor(): http://www.ecma-international.org/ecma-262/6.0/#sec-getsuperconstructor