Add a debugging utility to dump the memory layout of a JSCell.

[Mark Lam]

This is useful for some types of debugging work.

[Mark Lam]

Created attachment 346053 [details]
proposed patch.

[EWS Watchlist]

Comment on attachment 346053 [details]
proposed patch.

Attachment 346053 [details] did not pass jsc-ews (mac):
Output: https://webkit-queues.webkit.org/results/8697267

New failing tests:
stress/ftl-put-by-id-setter-exception-interesting-live-state.js.ftl-eager-no-cjit
apiTests

[Yusuke Suzuki]

Comment on attachment 346053 [details]
proposed patch.

View in context: https://bugs.webkit.org/attachment.cgi?id=346053&action=review

r=me

> Source/JavaScriptCore/ChangeLog:37
> +                structureID 369 0x171 structure 0x104b723e0
> +                indexingTypeAndMisc 11 0xb ArrayWithArrayStorage
> +                type 33 0x21

It would be nice if we can put classInfo's name too.

[Mark Lam]

(In reply to Yusuke Suzuki from comment #3)
> Comment on attachment 346053 [details]
> proposed patch.
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=346053&action=review
> 
> r=me

Thanks for the review.

> > Source/JavaScriptCore/ChangeLog:37
> > +                structureID 369 0x171 structure 0x104b723e0
> > +                indexingTypeAndMisc 11 0xb ArrayWithArrayStorage
> > +                type 33 0x21
> 
> It would be nice if we can put classInfo's name too.

We already do print the className e.g.
    <0x104bc8260, Object>
    <0x104bb4360, Array>

[Mark Lam]

Landed in r234363: <http://trac.webkit.org/r234363>.

[Radar WebKit Bug Importer]

<rdar://problem/42731814>