small changes, long build time

Pete Brunet peter.brunet at
Mon May 2 15:18:40 UTC 2016

On 4/30/16 2:32 AM, David Holmes wrote:
> On 30/04/2016 4:18 PM, Alan Bateman wrote:
>> On 30/04/2016 00:46, Pete Brunet wrote:
>>> Even small edits to code in the jdk source tree result in very long
>>> time
>>> build times now that jigsaw is merged in.  Is anyone working on trying
>>> to improve that?  Is there a workaround?
>> When you touch code in a module then you can use "make <module>" to just
>> rebuild that module. If you use "make" then it will rebuild that module
>> and all other modules that directly or transitively depend on it. There
>> are some tricks with sjavac but that is essentially it.
>> So which module are you changing? Is this Windows? Are you re-building
>> images each time?
My changes are in java.desktop and jdk.accessibility, split between
Java, Win, and Mac code.  I typically run "make images".  If I do "make
java.desktop" will that recreate files in images/jdk(jre)/bin?  At some
point soon I'll also be working in the JavaFX space but I think that's a
whole different story.
>> If you are re-building images every time then you'll see it creates the
>> jmods (packaged modules too). It is a bit expensive at moment, partly
>> because each package module generates hashes of the module artifact of
>> each dependency. This has been changed in an upcoming refresh so that
>> the hashes are generated and recorded once, this in turn allows for more
>> concurrency when generating the packaged modules. This may help you, but
>> hard to say.
> Just to add my concerns here, I was changing the launcher and building
> images and that caused the jmods to be rebuilt as well. I would not
> expect that so do we have missing dependency information in the build?
> David
>> -Alan

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