RFR: 8151600: Syntax for -Xlog complicates shell scripts

[Claes Redestad]

Hi,

On 2016-08-30 21:22, Robbin Ehn wrote:
> Hi Coleen, thanks for having a look at this,
>
> On 08/30/2016 04:48 PM, Coleen Phillimore wrote:
>>
>> Honestly, I think I can live with "*" rather than "+" and definitely
>> better than "%" (the latter seems a bit meaningless).
>
> I'm not removing asterisk, only adding a more shell friendly wildcard.

Too bad! I think asterisk implies something different intuitively than
what it actually does.

Example: -Xlog:class* means exactly "the union of all tag sets
containing the tag class", say: class, class+load, class+init

I had to read the JEP long and hard to realize it doesn't mean, say,
partial matches or similar expressions.

IMHO we would more succinctly express the intent with a new meta-tag
any:

-Xlog:class+any
-Xlog:gc+any

Optionally leave * as an alias for +any, since it's likely entrenched
already, but if there are compatibility issues with including * as
a control character in command lines maybe now is the (last possible)
time to consider dropping this?

/Claes

>
> E.g.
> rbt --jvm-args "-Xlog:gc*"
> should always have the intended effect regardless test type.
>
> /Robbin
>
>>
>> Coleen
>>
>> On 8/30/16 10:04 AM, Robbin Ehn wrote:
>>> Hi Dmitry,
>>>
>>> On 08/30/2016 03:56 PM, Dmitry Samersoff wrote:
>>>> Robbin,
>>>>
>>>> As far as I understand + is used as a delimiter
>>>> e.g. -Xlog:class+load
>>>>
>>>> It might be better to use % for wildcard.
>>>
>>> Yes it might, I thought trailing plus was best.
>>>
>>> E.g.
>>> "-Xlog:class+load*" would in this case be "-Xlog:class+load+"
>>>
>>> But if people prefer e.g. "-Xlog:class+load%" then we can go with that.
>>>
>>> Thanks for input!
>>>
>>> /Robbin
>>>
>>>>
>>>> -Dmitry
>>>>
>>>> On 2016-08-30 15:29, Robbin Ehn wrote:
>>>>> Hi all,
>>>>>
>>>>> The current syntax for -Xlog uses '*' for wildcard matching of tags.
>>>>> In shell scripts where * is unintended expanded causes problems.
>>>>> This patch adds the possibility to use trailing '+' instead.
>>>>>
>>>>> E.g.
>>>>> "-Xlog:gc+" is thus equivalent to "-Xlog:gc*"
>>>>>
>>>>> Tested with modified gtest test.
>>>>>
>>>>> Webrev: http://cr.openjdk.java.net/~rehn/8151600/hotspot.01/webrev/
>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8151600
>>>>>
>>>>> Thanks!
>>>>>
>>>>> /Robbin
>>>>
>>>>
>>