RFR (S) round 0 for 8141068 Refactor -XXFlags= code in preparation for removal

[Coleen Phillimore]

On 11/11/15 11:36 AM, Daniel D. Daugherty wrote:
> This needs a little bit of clarification:
>
> 3976 jint Arguments::match_special_option_and_act(const 
> JavaVMInitArgs* args,
> 3977                                              char ** 
> vm_options_file,
> 3978 ScopedVMInitArgs* args_out) {
>
> The 'vm_options_file' parameter is currently used for two things:
>
> 1) when the parameter is non-NULL, that indicates the caller
>    supports '-XX:VMOptionsFile'; currently only the cmd line
>    option bucket supports '-XX:VMOptionsFile'

The args_out != NULL parameter indicates the same thing.
> 2) makes sure that only one -XX:VMOptionsFile=foo option is
>    specified on the cmd line

You can do that with a local variable vm_options_file in 
match_special_option_and_act.

So it can be trivially removed.   But it's not a big deal.

Coleen
>
> Restriction #1 is implemented by:
>
> 3994       if (vm_options_file != NULL) {
> <snip>
> 4022       } else {
> 4023         jio_fprintf(defaultStream::error_stream(),
> 4024                     "VM options file is only supported on the 
> command line\n");
> 4025         return JNI_EINVAL;
> 4026       }
>
> Restriction #2 is implemented by:
>
> 3994       if (vm_options_file != NULL) {
> 3995         // The caller accepts -XX:VMOptionsFile
> 3996         if (*vm_options_file != NULL) {
> 3997           jio_fprintf(defaultStream::error_stream(),
> 3998                       "The VM Options file can only be specified 
> once and "
> 3999                       "only on the command line.\n");
> 4000           return JNI_EINVAL;
> 4001         }
>
> So the 'vm_options_file' parameter cannot be removed at this
> time without changing the current set of restrictions on the
> '-XX:VMOptionsFile' option. Ron has another bug looking at
> lifting those restrictions:
>
> JDK-8135198 Specifying a vm options file should not be limited
>             to only once on the command line
> https://bugs.openjdk.java.net/browse/JDK-8135198
>
> JDK-8135198 will require a CCC request in order to change the
> semantics that were defined in the original work (JDK-8061999).
>
> Dan
>
>
> On 11/10/15 2:02 PM, Ron Durbin wrote:
>> Coleen
>>
>> This is to formally respond to your email.  Dan and I agreed the 
>> change you are requesting should be done, but not
>> in this change set.  Keeping this change set to only XX:Flags 
>> changes. A future change set that could clean up
>> the options file processing should address your issue.
>>
>> Ron
>>
>>
>>> -----Original Message-----
>>> From: Coleen Phillimore
>>> Sent: Monday, November 09, 2015 2:03 PM
>>> To: hotspot-runtime-dev at openjdk.java.net
>>> Subject: Re: RFR (S) round 0 for 8141068 Refactor -XXFlags= code in 
>>> preparation for removal
>>>
>>>
>>> Ron,
>>>
>>> This looks really good!  Although I don't see why you need to pass
>>> vm_options_file argument into match_special_options_and_act now since
>>> it's not used afterward, so you only have to pass one NULL in the cases
>>> where vm_options_file is not allowed.
>>>
>>> thanks,
>>> Coleen
>>>
>>> On 11/6/15 2:05 PM, Ron Durbin wrote:
>>>> This bug fix consists of a refactoring/cleanup of the -XX:Flags code.
>>>>
>>>> Webrev:
>>>> http://cr.openjdk.java.net/~rdurbin/8141068_OCR0_JDK9_webrev
>>>>
>>>>
>>>> Bug report:
>>>> https://bugs.openjdk.java.net/browse/JDK-8141068
>>>>
>>>> This bug fix has been tested on:
>>>>      OS:
>>>>        Solaris, MAC, Windows, Linux
>>>>      Tests:
>>>>        Manual unit tests
>>>>        JPRT with -testset hotspot(including the SQE current test 
>>>> coverage for this feature.)
>