[webkit-reviews] review granted: [Bug 212645] SpeculativeJIT::compileDateGet()'s slow path does need a exception check. : [Attachment 401003] proposed patch.

[bugzilla-daemon at webkit.org]

Yusuke Suzuki <ysuzuki at apple.com> has granted Mark Lam <mark.lam at apple.com>'s
request for review:
Bug 212645: SpeculativeJIT::compileDateGet()'s slow path does need a exception
check.
https://bugs.webkit.org/show_bug.cgi?id=212645

Attachment 401003: proposed patch.

https://bugs.webkit.org/attachment.cgi?id=401003&action=review




--- Comment #4 from Yusuke Suzuki <ysuzuki at apple.com> ---
Comment on attachment 401003
  --> https://bugs.webkit.org/attachment.cgi?id=401003
proposed patch.

View in context: https://bugs.webkit.org/attachment.cgi?id=401003&action=review

r=me

> Source/JavaScriptCore/ChangeLog:3
> +	   SpeculativeJIT::compileDateGet()'s slow path does need a exception
check.

/does/does not/

> Source/JavaScriptCore/ChangeLog:33
> +	   The patch also proves that all the operation functions cannot throw
any exceptions.
> +	   Previously, the operations passes a VM& to the Date functions.  The
purpose for
> +	   doing this is so that the Date functions can work with a few date
cache data
> +	   structures stored as VM fields.
> +
> +	   This patch refactors those VM fields into a VM::DateCache struct,
and changed all
> +	   those Date functions to take a VM::DateCache& instead of a VM&. 
Since the Date
> +	   functions no longer take a VM&, this proves that they cannot throw
because they
> +	   would need a VM& to make a ThrowScope in order to throw.

I think passing VM* is enough to represent that this function never throws an
error. Because error requires error objects, error-throwing function requires
JSGlobalObject* instead.
So, if the function does not take JSGlobalObject*, we can assume that it will
not throw an error (and that's why I didn't pass JSGlobalObject* to these
slowpath functions.)