[J11] Prepare Java 11 Support

[cdietrich]

Xtext should not "explode" with Java 11

• JavaVersion constant and its from and to conversions
  Wizard
• new Maven/Gradle Dependencies to JDT we consume needed
• new ASM needed? (https://dev.eclipse.org/ipzilla/show_bug.cgi?id=17016) Update to ASM7 #1325 ☑️
• new Tycho Version needed? yes we need tycho 1.3 Update to Tycho 1.3 #1322
• Gradle? gradle 4.10.2 should be fine. ☑️
• Maven?
• new Guava?
• new Guice?
• Function wise (do not explode)

[cdietrich]

see #2578

[cdietrich]

see https://groups.google.com/forum/#!topic/xtend-lang/T2TLFWVl_C4

[cdietrich]

wont ship this with 2.15 so moved to 2.16

[jpaw]

An upgrade of guice will be required. As a quick test, I changed the guice release from 3.0 to 4.2.0. In xtext-core, then 12 tests fail (but that's less than 1% of all tests :-)).
In xtext-xtend, I also had to upgrade org.eclipse.core.runtime in order to avoid some signature mismatch exception, but afterwards, the resulting xtend-maven-plugin does not show the warnings about illegal reflective access any more when running with Java 10. Java 11 still does not work, so there's more to update, I will keep testing.
(Btw, I used the "no_aop" classifier for guice, this did not make any difference related to the number of failing tests. guice still bundles / repackages cglib and asm, and 4.2.0 still does not use the most recent ones, but with the classifiers "no_aop" and "classes" versions without that are available as well.)

[cdietrich]

how did you deal with guice 4.x needing a newer guava? see eclipse/xtext-core#393

[cdietrich]

@szarnekow do you know of any ussages of the guice aop part? do you remember which version of guice we use? https://dev.eclipse.org/ipzilla/show_bug.cgi?id=6118 reads like we use the non aop variant at lease eclipse/manifest wise

[jpaw]

I did not get any exception of the type described in eclipse/xtext-core#393.
Related to the classifiers, I got the information from this discussion: google/guice#1198

[cdietrich]

Another thing I don’t know is that such a change would mean for (binary) compatibility and if it would require a Xtext 3.0 @svenefftinge can you share your knowledge with that

[cdietrich]

@jpaw did you investigate if this can be done without a guice/guava bump? for java 9 and 10 it was possible. or did you do the bump to get rid of the reflection warnings?

[svenefftinge]

We should not bump the major version. Also see discussion here: https://dev.eclipse.org/mhonarc/lists/modeling-pmc/msg04475.html

[jpaw]

Related to the version bump of guava:
guice used 19.0 until very recently, in commits eface22... (just before the 4.2.0 tag) and in 289073...
apparently mainly to be able to use a newer version of the truth test library (that upgrade was done after the 4.2.0 tag). This would allow the version range [19.0, 20.0 and 22.0) which should work for xtext as well as guice. I rebuilt guice 4.2.0, but with a guava 20.0 dependency, and same results (20.0 is the last guava release which offers Java 6 compatibility).

Related to guice: xtext currently uses 3.0, which does not yet offer the no_aop version. guice 3.x is officially not even compatible with Java 8 (guice 4.0 ff are), so I doubt it will work with Java 11.

With my test builds of the xtext / xtend plugins, I'm currently stuck with "ResourceNotLoaded" or
org.eclipse.emf.ecore.resource.impl.ResourceSetImpl$1DiagnosticWrappedException: org.eclipse.xtext.common.types.access.TypeResource$CannotLoadTypeResourceException: java.lang.UnsupportedOperationException at org.eclipse.emf.ecore.resource.impl.ResourceSetImpl.handleDemandLoadException (ResourceSetImpl.java:319) at org.eclipse.emf.ecore.resource.impl.ResourceSetImpl.demandLoadHelper (ResourceSetImpl.java:278) at org.eclipse.xtext.resource.XtextResourceSet.getResource (XtextResourceSet.java:265)
I will retest this with emf 2.15.0 as soon as that has been released (current test used emf 2.12.0).

[cdietrich]

the current guice (the one consumved via orbit has aop switched off) so you are taking about the maven/gradle dependency?
it was working with java 9 and 10. the question: are we talking about the xtext built itself or projects using xtext?

[jpaw]

I'm currently mainly interested in using xtext, that is, invoking xtext-maven-plugin and xtend-maven-plugin from a maven build job which is executed by JDK 11.
Of course the fallback would be to run the build with Java 8 and to only use Java 11 at runtime, but that would restrict using Java 9/10/11 features to be used in pure Java projects only.

[cdietrich]

I would have expected that would have worked by simply bumping the jdt version (not out yet) and introducing a new entry in the javaversion enum

[cdietrich]

we require asm7 and the usage of OpCodes.ASM7 to get this running

[cdietrich]

Address javax.annotation.Generated

[cdietrich]

we should consider replacing the 3 single jdt plugins we consume from maven with the ecj jar (needs deeper investigation, e.g. how it relates to platform jars)
tycho does the same eclipse-tycho/tycho@8368ab9

[chrswk]

So Java 11 support is planned for 2.16.0, correct? Do you have any idea about the schedule?

[cdietrich]

2.16 is planned for 2018-12. We are still lining up for

• ASM 7 final at maven and eclipse orbit
• Tycho 1.3
• Maven Consumable Artifacts for JDT

[chrswk]

Great, thanks for the information! 👍

[cdietrich]

emf.codegen.ecore needs org.eclipse.jdt.core.formatter.CodeFormatter which is not part of ecj

https://repo.eclipse.org/content/repositories/eclipse-staging/org/eclipse/jdt/org.eclipse.jdt.core/ does not contains compiler tool

created https://bugs.eclipse.org/bugs/show_bug.cgi?id=540530

[cdietrich]

Fixed in Xtext/Xtend 2.17