Bug 155099 – [ES6] Implement Proxy.[[GetPrototypeOf]]

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Saam Barati]

...

[Saam Barati]

Created attachment 273207 [details]
patch

[WebKit Commit Bot]

Attachment 273207 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/runtime/ProxyObject.cpp:1051:  Multi line control clauses should use braces.  [whitespace/braces] [4]
ERROR: Source/JavaScriptCore/runtime/ProxyObject.cpp:1053:  Weird number of spaces at line-start.  Are you using a 4-space indent?  [whitespace/indent] [3]
Total errors found: 2 in 5 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Mark Lam]

Comment on attachment 273207 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=273207&action=review

> Source/JavaScriptCore/runtime/ProxyObject.cpp:1035
> +    if (handlerValue.isNull()) {
> +        throwVMTypeError(exec, ASCIILiteral("Proxy 'handler' is null. It should be an Object."));
> +        return JSValue();
> +    }

The only way to get to performGetPrototype() is thru performProxyGet().  The only way to get to performProxyGet() is thru ProxyObject::getOwnPropertySlotCommon() returning a slot getter.  And ProxyObject::getOwnPropertySlotCommon() can only be called on a ProxyObject.  Hence, shouldn't this be an assert instead?

[Mark Lam]

Comment on attachment 273207 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=273207&action=review

>> Source/JavaScriptCore/runtime/ProxyObject.cpp:1035
>> +    }
> 
> The only way to get to performGetPrototype() is thru performProxyGet().  The only way to get to performProxyGet() is thru ProxyObject::getOwnPropertySlotCommon() returning a slot getter.  And ProxyObject::getOwnPropertySlotCommon() can only be called on a ProxyObject.  Hence, shouldn't this be an assert instead?

My mistake.  I didn't see the call from ProxyObject::getPrototype() below.

[Saam Barati]

I spoke with Mark in person.
For posterity:
calls to "proxy.__proto__" will route through performProxyGet.
Reflect/Object.getOwnPrototype will call straight through
to the method table implementation which calls through
to performProxyGet(.).

[Mark Lam]

Comment on attachment 273207 [details]
patch

r=me

[Saam Barati]

thanks for the review.
Landed in:
http://trac.webkit.org/changeset/197711