Build failure with Java 10 due to the removal of javah

[ebourg]

Hi, jffi fails to build with Java 10 or later due to the removal of the javah tool. We fixed this in Debian by:

• removing the <javah> task in the Ant build
• adding the nativeHeaderDir to the <javac> tasks
• adding the @Native annotation (introduced in Java 8) to the fields in ObjectBuffer.java and Version.java used by the native code

Here is the patch we used: https://salsa.debian.org/java-team/jffi/blob/master/debian/patches/java10-compatibility.patch

[headius]

@ebourg Thanks for the report and patch! I am a bit wary about using a Java 8-only annotation, though. We have at the very least JRuby 9.1.x which supports Java 7, and there are others out there using JNR-* on releases earlier than 8. Is there a way to do this so it works on both 7 and 8?

[ebourg]

Maybe by copying the java.lang.annotation.Native class into the project? Adding a bogus native method in the Version class should also work.

[headius]

Honestly moving to Java 8 sounds like less hassle, but I'm not sure how other users might feel about that. I will play with this patch tomorrow, but if you know: does the resulting library still work with Java 7?

cc @enebo

[headius]

Ok, so I've created https://github.com/jnr/jnr-a64asm but not pushed anything. Feel free to send a pull request and we can get everything in the right places for release. Welcome to the project!

[ebourg]

does the resulting library still work with Java 7

It may if you ensure no Java 8+ method is used, with animal-sniffer for example.

[re-thc]

Moving to Java 8 would be good for the next release. Java 7 usage can be kept with the current release.

[ikelos]

Any progress on this, or a 1.3 release? 1.2.22 still throws this error under Openjdk-11...