Problems with JDK 10

[Stefan Marr]

Hi:

Are there any know problems with Truffle and JDK 10?
Since Homebrew updated its java cask to JDK 10, I got my builds failing on Travis.
My setup uses the `--release 8` flag, so, I was hoping to avoid any issues.

The javac output, when compiling the whole project is unfortunately less than helpful.
(see https://travis-ci.org/smarr/SOMns/jobs/356726221#L2353,
 I can only see “package does not exist”, or "cannot find symbol" errors.)

It looks to me as if the annotation processor is failing to run.

Locally, I have been trying to find out whether any specific single file is not building correctly.
So, I went, compiled everything with Java 9, and then tried compiling some subset with Java 10.

For individual files, nothing seems to be wrong.
However, when I clean out the compilation for all my builtin functions (som.primitives),
I get the following lovely error:

```
    [javac] /Users/smarr/Projects/SOM/SOMns/src/som/primitives/ActivitySpawn.java:167: error: expression not allowed as annotation value
    [javac]   @Primitive(primitive = "threading:threadSpawn:with:",
    [javac]   ^
```

The same compiles fine with JDK 8 and 9.

Even worse, just cleaning out ActivitySpawn compiles fine too:

```
$ rm ./src_gen/som/primitives/ActivitySpawnFactory.java ./build/classes/som/primitives/ActivitySpawn*
$ ant -Dskip.graal=true compile-som
Buildfile: /Users/smarr/Projects/SOM/SOMns/build.xml
     [echo]
     [echo]         ant.java.version: 9
     [echo]         java.version:     10
     [echo]         is.atLeastJava9:  true
     [echo]

compile-som:
    [javac] Compiling 1 source file to /Users/smarr/Projects/SOM/SOMns/build/classes
    [javac] warning: No processor claimed any of these annotations: com.oracle.truffle.api.nodes.Node.Child,com.oracle.truffle.api.dsl.Cached,com.oracle.truffle.api.CompilerDirectives.CompilationFinal,bd.primitives.Primitive.Container,com.oracle.truffle.api.CompilerDirectives.TruffleBoundary,com.oracle.truffle.api.dsl.GenerateNodeFactory,com.oracle.truffle.api.dsl.Specialization,com.oracle.truffle.api.dsl.NodeChild,com.oracle.truffle.api.dsl.ImportStatic
    [javac] warning: No processor claimed any of these annotations: com.oracle.truffle.api.dsl.GeneratedBy,com.oracle.truffle.api.nodes.Node.Child,com.oracle.truffle.api.CompilerDirectives.CompilationFinal
    [javac] 2 warnings

BUILD SUCCESSFUL
Total time: 1 second
```

Did anyone see anything like this before?

Might this be a javac bug?

Thanks
Stefan

-- 
Stefan Marr
School of Computing, University of Kent
http://stefan-marr.de/research/