Request for review (XS): JDK-8006430: TraceTypeProfile is a product flag while it should be a diagnostic flag

Krystal Mo krystal.mo at oracle.com
Wed Feb 13 18:02:29 PST 2013


Hi Chris,

I think Staffan is asking why we differentiate {C2 diagnostic} and 
friends from {diagnostic}.

- Kris

On 02/13/2013 12:26 PM, Christian Thalinger wrote:
> On Feb 11, 2013, at 12:57 AM, Staffan Larsen <staffan.larsen at oracle.com> wrote:
>
>> Forgive my ignorance, but why do diagnostic and experimental flags have different "kinds" depending on what part of the VM they belong to? Can't they all be just "{experimental}" or "{diagnostic}"? I don't see where the additional C1/C2/ARCH/Shark information is used.
> Are you asking why we have experimental and diagnostic flags?
>
> -- Chris
>
>> Thanks,
>> /Staffan
>>
>> On 9 feb 2013, at 02:23, Krystal Mo <krystal.mo at oracle.com> wrote:
>>
>>> Hi all,
>>>
>>> Could I have a couple of reviews for this fix, please?
>>>
>>> Webrev: http://cr.openjdk.java.net/~kmo/8006430/webrev.00/
>>> Bug: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8006430
>>>
>>> This bug is actually not a regression from JDK-7198499, but a long time issue that C2 diagnostic flags were never treated as being "diagnostic" since the OpenJDK Mercurial repo history began (duke at 0).
>>>
>>> The problem is, C2 diagnostic flags have the kind "{C2 diagnostic}", but Flag::is_unlocked() only cared to test "{diagnostic}".
>>> So the fix is straighforward -- find out how many other "diagnostic" and "experimental" flag kinds there are, and check them.
>>>
>>> I didn't just check if the string ends with "diagnostic}" or "experimental}" because I think that's too permissive, but I don't have a strong opinion on that.
>>> If reviews form a consensus that checking just the postfix is good enough, I can make the change that way.
>>>
>>> Care has to be taken if new diagnostic/experimental flag kinds are added to other components in the future, e.g. C1.
>>>
>>> Tested with JPRT and these flags by hand:
>>> C2 diagnostic: TraceTypeProfile, LoopLimitCheck, RangeLimitCheck
>>> ARCH diagnostic: UseIncDec
>>>
>>> Thanks,
>>> Kris



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