JDK 9 configuration options

[Alan Bateman]

On 09/09/2016 16:31, Stephen Felts wrote:

> :
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>   
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> 2. With the new argument syntax in JDK 9 build 132, the launcher arguments now match the command line arguments.  That’s a big step in the right direction.  However, duplicates are a fatal error.  So doing
>
> export _JAVA_OPTIONS=-XX:VMOptionsFile=/mydir/jdk9args
> java @/mydir/jdk9args something
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> fails.
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> If one framework needs java.xml.bind and another framework uses the same module, that should just work.  If one needs bind and another needs jdk.rmic, I shouldn’t have to concatenate the two framework argument files together and manually merge the add-modules arguments together.  It seems conceptually simple to add the required lists together in java or javac.  The same is true for other things like exports, module path, upgrade module path, patch module, etc.
>
In the case of --add-modules then Mandy and Harold have changes in 
review on hotspot-runtime-dev and core-libs-dev to change this into a 
repeating option (it's currently last one wins). There will be follow-on 
work needed in javac and other tools to get things aligned. There is 
related patch coming that will propose to update the exiting repeating 
options (specifically --add-exports and --add-reads) to tolerate dups. 
Again, the complete solution requires updates to javac, maybe jlink, to 
get everything consistent. Assuming there aren't any issues when I would 
expect JEP 261 be to updated to reflect these proposals.

-Alan