Please review the change to support dual mode launcher

[Mandy Chung]

On 03/30/10 08:44, Jonathan Gibbons wrote:
> Alan Bateman wrote:
>> The change seems reasonable to me. I realize the switch is 
>> temporary/internal only but would it be better to make it -X option? 

Thanks for reminding me.  Yes, I should use -X option.

>> Maybe -Xlegacymode and -Xmodulesmode?
>>
>> -Alan.
>>
> I think an option taking a value is better than a pair of boolean options.
> Separately, note that users will have to use -J to prefix the option, 
> e.g. -J-Xmode:legacy. That's not an issue, but just remember that when 
> trying out the option, and when documenting it.

I updated it to take this new option -Xmode:legacy and -Xmode:module.

> javadoc is similar to the other tools. 

Ok.   javadoc will run in legacy mode by default until it's updated to 
look for the platform classes from jigsaw.

> The requirement for all of these 
> tools is that the system property sun.boot.class.path is set to the 
> platform class path. This is embodied in the code that handles these 
> tools path options, Paths.java, round about line 344
> 
> http://hg.openjdk.java.net/jdk7/tl/langtools/file/de6375751eb7/src/share/classes/com/sun/tools/javac/file/Paths.java. 
> 
> 
> Thus the tools could operate in "hybrid" mode, where the tool's JVM runs 
> in module mode, but sun.boot.class.path is set to a value that would 
> allow the tool itself to operate in legacy mode. The distinction is 
> similar to the existing distinction between -Xbootclasspath and 
> -J-Xbootclasspath seen by all the tools.

Per our discussion yesterday, we want these tools to operate in 
"jigsaw-enabled" mode like the new javac.  The tools can then switch to 
run in module mode.

Thanks
Mandy