547046 - the proper test whether an object can be called in IsCallable, not VALUE_IS_FUNCTION

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Andreas Gal :gal]

The following doesn't work:

Function.prototype.apply.call(someRegExp, someRegExp, targetString)

This also affects other callable objects such as the proposed Harmony proxies.

Comment 1

[Jeff Walden [:Waldo]]

Bug 539170 would probably fix this.

ES5 says regular expressions are callable?  :-(

Comment 2

[Brendan Eich [:brendan]]

(In reply to comment #1)
> ES5 says regular expressions are callable?  :-(

ES5 does not specify a [[Call]] internal method for RegExp -- it's just like ES3. We should see about dropping callable regexps. Not sure how that will go down on the web, since IIRC WebKit followed us. Is there a bug on this?

/be

Comment 3

[Brendan Eich [:brendan]]

(In reply to comment #0)
> The following doesn't work:
> 
> Function.prototype.apply.call(someRegExp, someRegExp, targetString)

IOW (followup on comment 2) this is just a handy test, not a normative spec thing.

/be

Comment 4

[Andreas Gal :gal]

Attachment: patch

Comment 5

[Andreas Gal :gal]

Attachment: patch

Comment 6

[Andreas Gal :gal]

This fixes the two most obvious offenders. This blocks my proxy work, so I will get it reviewed and landed.

Comment 7

[Andreas Gal :gal]

Test case with proxies:

var proxy = Proxy.createFunction({ invoke: function(obj,name,args) { return Function.prototype[name].apply(obj, args); },
get: function(obj,name) { return Function.prototype[name]; } }, function () { return "ok"; });

print(proxy.call());

should print out "ok", without the patch the result is an error

Comment 8

[Andreas Gal :gal]

http://hg.mozilla.org/tracemonkey/rev/16c93a834c66

Comment 9

[Robert Sayre]

http://hg.mozilla.org/mozilla-central/rev/16c93a834c66