Bug 190740 – vmCall should check if we may exit before emitting an OSR exit due to exceptions

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

[Saam Barati]

Otherwise, we may be in a state where we don't have a valid exit state. So if we exitted at that point, we wouldn't know how to recover certain values. validateFTLOSRExitLiveness catches these issues. The solution is to not emit an exit due to an exception being thrown if the node we're compiling isn't allowed to throw. This should also be a tiny bit of a speedup/code size reduction.

[Saam Barati]

<rdar://problem/45220139>

[Saam Barati]

Created attachment 352746 [details]
patch

[EWS Watchlist]

Attachment 352746 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/ChangeLog:13:  Line contains tab character.  [whitespace/tab] [5]
Total errors found: 1 in 4 files


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

[Saam Barati]

Created attachment 352747 [details]
patch

[Mark Lam]

Comment on attachment 352747 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=352747&action=review

r=me

> Source/JavaScriptCore/ChangeLog:21
> +        emitting an exception check. A node node being able to exit implies

I think you meant to say "A node not being able"

> Source/JavaScriptCore/ChangeLog:22
> +        that it can't exit for exceptions (hence, it can't throw an exception).

I suggest saying "it also can't".

[Saam Barati]

Created attachment 352814 [details]
patch for landing

[WebKit Commit Bot]

Comment on attachment 352814 [details]
patch for landing

Clearing flags on attachment: 352814

Committed r237297: <https://trac.webkit.org/changeset/237297>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.