Moe Sync

[cpovirk]

This code has been reviewed and submitted internally. Feel free to discuss on the PR and we can submit follow-up changes as necessary.

Commits:

Travis: use 'openjdk8' instead of 'oraclejdk8'

(This now restores coverage for 8, and I made a similar change for 11.)

Fixes #89

d30e344

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maven-compiler-plugin 3.8.1

Fixes #90

54912ec

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Run Error Prone as a plugin.

If run in the old style, it uses javac9, which can't handle the Java 11 class files in the JDK11 bootclasspath.

This follows the instructions at https://errorprone.info/docs/installation#maven

Note also the need to include -Xep:BetaApi:OFF in the same arg as -Xplugin:ErrorProne: google/error-prone#1136 (comment) google/error-prone#1115

(Also, incidentally update Error Prone itself. I forget whether I had a Java-11-related reason for that, but it seems like a good idea.)

7e467aa

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Prepare Javadoc for Java 11, and make other improvements:

• Move nearly all Javadoc configuration to the parent POM.
• Update Guava and ICU4J link locations. The current links resolve to the Javadoc -- but only after a redirect, which Javadoc doesn't like: https://bugs.openjdk.java.net/browse/JDK-8190312
• Update maven-javadoc-plugin to 3.1.1. (This version knows how to work around the aforementioned redirect problem, should it happen again.)
• Add links to Checker Framework. For some reason, this isn't working under Java 11. I haven't investigated.
• Disable detectJavaApiLink, and fill in https://docs.oracle.com/javase/9/docs/api/ for Java 8 and https://docs.oracle.com/en/java/javase/11/docs/api/ for newer versions. (I've tested only with Java 8 and 11, so hopefully the "newer versions" behavior is OK for 9 and 10.)
  It does look like it may be necessary to duplicate all the links in 3 places :
  This is all in service of preventing:
  [ERROR] Exit code: 1 - javadoc: error - The code being documented uses modules but the packages defined in https://docs.oracle.com/javase/9/docs/api/ are in the unnamed module.
  Traditionally we solve this problem by setting 8 on Javadoc (CL 235241314, CL 236159968). That would probably work here, but I've been experimenting with 9 (for proper modules support in jimfs), so that might not be an option soon. Or maybe it still would be, but I'd have to exclude module-info.java, but then I wonder if that will trigger modules problems? In any case, it seems more future-proof to solve this the right(?) way.

7b2eccd

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