[webkit-reviews] review requested: [Bug 172888] [JSC] Create a fast path to Object.defineProperty : [Attachment 315616] WIP - It starts

[bugzilla-daemon at webkit.org]

Caio Lima <ticaiolima at gmail.com> has asked  for review:
Bug 172888: [JSC] Create a fast path to Object.defineProperty
https://bugs.webkit.org/show_bug.cgi?id=172888

Attachment 315616: WIP - It starts

https://bugs.webkit.org/attachment.cgi?id=315616&action=review




--- Comment #5 from Caio Lima <ticaiolima at gmail.com> ---
Created attachment 315616

  --> https://bugs.webkit.org/attachment.cgi?id=315616&action=review

WIP - It starts

RFC here. It is just starting the implementation.

This implementation isn't spec compliant and I'm thinking create intrinsic
functions to verify if the descriptor has some property without user observable
behavior, otherwise it will be classified as escaped object if we use "in"
operation.

I'm also in doubt if there is another case where the user-observable behavior
can be captured other than proxies case, because according the spec[1],
ToPropertyDescriptor operation is called.

The fast case I'm planing here is when we have "Object.defineProperty(a, "foo",
{/* descriptor */})" and descriptor is a JS Object allocated in DFG with
"NewObject".

[1]-https://tc39.github.io/ecma262/#sec-object.defineproperty