On 03/02/2015 04:09, Martin Buchholz wrote:
I'm trying to use jdk9-b34 and see that rt.jar and friends are gone.
Are we in jigsaw-land yet?
javac doesn't seem to know about any -modulepath flag yet.
(javac -help, javac -X is module-unaware)
How do I specify a bootclasspath for jdk9-b34?
You can't use a jimage with -bootclasspath, and -modulepath doesn't seem to
work (even though I see references to it in the javac sources)
How will one be able to use javac/jdk10 to target jdk9? Traditionally,
-target 9 -source 9 and -bootclasspath with some collection of jdk9 jar
files. But jdk9 bootclasspath jars are gone, and I don't see anything to
replace it?
(Background: trying to fix up jsr166 ant build script for jdk9-latest)
JEP 220 went into jdk9-b41 so that's the first build where you should
have noticed the change to the runtime image layout and where rt.jar and
tools.jar have been replaced. Prior to this then JEP 201 went in to
reorganize the source code by module and change significantly the build
so that the compilation unit is module rather than the java sources in
each repository.
We're still not in "module land" yet, there's a standard module system
for JSR 376 to define and there will be JEP for the implementation too.
So too early to be looking for options like -modulepath.
For tools that need to access the classes and resources in another
runtime image then the proposal (in JEP 220) is the jrt file system
provider. At this time, this works for a tool running on JDK 9 to access
the contents of its own image, or a tool running on JDK 8 to access the
contents of a target JDK 9 image. So far then javac, jdeps and rmic have
been changed to use the file system API. We're not yet at the point
where a tool running on a build of JDK 9 or JDK 10 can access the
contents of different JDK 9 or JDK 10 build but we'll get there (in a
few months I hope, there are a few issues to sort out first and a number
of other big changes in this areas that are higher priority at the moment).
For javac then there are other ideas to support compiling for previous
releases, Jon might want to say more on this.
-Alan
