Annotation processor support broken (regression)

[tbroyer]

Annotation processor support broken (regression)

[tbroyer]

Ah right. I know what's wrong, but unfortunately I'm not sure how to fix it properly.

The commit that caused the regression was dc1076e, and the problem is that sources are (probably) generated during the compile phase which comes after generate-resources, and even after process-resources.

One possible fix would be to partially revert the commit, but exclude those compile source roots that are already included as resources (using the same conflict-detection as in import-sources which avoid declaring resources for source roots that are already included as resources), on the principle that generated sources are very unlikely to be subject to filtering or relocation (and if that's what one wants, he'd have to generate them during the generate-sources phase, e.g. calling compile:compiler with <proc>only</proc>).

Anyway, time to add an integration test for that that'll serve as a non-regression test.

Thanks for the report.

[tbroyer]

Oh crap, the above wouldn't work for gwt-lib packaging unless I replace the use of jar:jar with a custom mojo. Maven is driving me insane, once again…

[tbroyer]

Workaround: use resources:copy-resources at process-classes phase (or later). You don't actually need the build-helper-maven-plugin when building (but it'll be handy for gwt:devmode / gwt:codeserver).

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-resources-plugin</artifactId>
  <version>2.7</version>
  <executions>
    <execution>
      <id>add-generated-sources</id>
      <phase>process-classes</phase>
      <goals>
        <goal>copy-resources</goal>
      </goals>
      <configuration>
        <outputDirectory>${project.build.outputDirectory}</outputDirectory>
        <resources>
          <resource>
            <directory>${project.build.directory}/generated-sources/annotations</directory>
          </resource>
        </resources>
      </configuration>
    </execution>
  </executions>
</plugin>

…or generate sources at generate-sources phase (see previous comment)

[tbroyer]

FWIW, another workaround is to postpone resources:resources to the process-classes phase. See in https://github.com/google/auto/blob/1ba4c40596f887f5040a60cd407b94751d65589f/value/src/it/gwtserializer/pom.xml#L102-L113 how I postponed resources:testResources to the process-test-classes phase.

That said, I think I'll add two new mojos to copy generated sources at process-classes (or maybe prepare-package) and process-test-classes. That'll work for both gwt-lib and gwt-app.

[hpehl]

The workaround with resources:copy-resources works for me. Thanks @tbroyer!

[tbroyer]

Finally got to fix it by reworking the import-sources and import-test-sources mojos (d80bc8d) and added integration tests for annotation processing (259960d).

Would you mind testing with the latest snapshot?

(note that the sources are now copied –similarly to resources:copy-resources– during the process-classes phase, so if you need build-helper-maven-plugin to add the generated sources as source roots you might have to bind it to the compile phase to make it run before gwt:import-sources, but after compile:compile; in the integration tests I used a recent version of the maven-compiler-plugin that automatically does that, but it has a bug when re-running the compilation without cleaning; this is not a problem for integration tests but might be a blocker for anyone trying to do "real things" with Maven)

[branflake2267]

Nice job

[hpehl]

The latest snapshot works for my setup.

[tbroyer]

It took me way too long, but I'm finally releasing a 1.0-rc-6 (should appear in Central soon)

[chris-becker]

Should this be working with 1.0-rc-6 ? Using that version to package a gwt-lib, sources from stuff generated by APT don't end up in my jar.

[tbroyer]

@chris-becker Yes it should; but you have to make sure your generated sources are added as source roots (i.e. either use maven-compiler-plugin 3.5.1 or greater –technically 3.2 or greater, but 3.2 to 3.5 are basically unusable when doing annotation processing due to MCOMPILER-235–, or use the build-helper-maven-plugin's add-source goal)

[chris-becker]

Doesn't work for me, see enclosed repo:
repo.zip

In maven's log, gwt-maven-plugin:1.0-rc-6:import-sources runs pretty early, right after build-helper-maven-plugin:1.12:add-source (which doesn't seem to have anything to add yet :), and way before maven-compiler-plugin:3.6.0:compile :

[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ repo ---
[INFO] Deleting C:\Develop\IProjects\bpm\repo\target
[INFO]
[INFO] --- gwt-maven-plugin:1.0-rc-6:enforce-encoding (default-enforce-encoding) @ repo ---
[INFO]
[INFO] --- gwt-maven-plugin:1.0-rc-6:add-super-sources (default-add-super-sources) @ repo ---
[INFO]
[INFO] --- gwt-maven-plugin:1.0-rc-6:add-test-super-sources (default-add-test-super-sources) @ repo ---
[INFO]
[INFO] --- build-helper-maven-plugin:1.12:add-source (add-source) @ repo ---
[INFO] Source directory: C:\Develop\IProjects\bpm\repo\target\generated-sources\annotations added.
[INFO]
[INFO] --- gwt-maven-plugin:1.0-rc-6:import-sources (default-import-sources) @ repo ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] skip non existing resourceDirectory C:\Develop\IProjects\bpm\repo\target\generated-sources\annotations
[INFO]
[INFO] --- gwt-maven-plugin:1.0-rc-6:generate-module (default-generate-module) @ repo ---
[INFO]
[INFO] --- gwt-maven-plugin:1.0-rc-6:generate-module-metadata (default-generate-module-metadata) @ repo ---
[INFO]
[INFO] --- maven-resources-plugin:3.0.1:resources (default-resources) @ repo ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] skip non existing resourceDirectory C:\Develop\IProjects\bpm\repo\src\main\super
[INFO]
[INFO] --- maven-compiler-plugin:3.6.0:compile (default-compile) @ repo ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to C:\Develop\IProjects\bpm\repo\target\classes
[INFO]
[INFO] --- gwt-maven-plugin:1.0-rc-6:import-test-sources (default-import-test-sources) @ repo ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\Develop\IProjects\bpm\repo\src\test\java
[INFO]
[INFO] --- maven-resources-plugin:3.0.1:testResources (default-testResources) @ repo ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\Develop\IProjects\bpm\repo\src\test\resources
[INFO] skip non existing resourceDirectory C:\Develop\IProjects\bpm\repo\src\test\super
[INFO]
[INFO] --- maven-compiler-plugin:3.6.0:testCompile (default-testCompile) @ repo ---
[INFO] No sources to compile
[INFO]
[INFO] --- gwt-maven-plugin:1.0-rc-6:test (default-test) @ repo ---
[INFO] No tests to run.
[INFO]
[INFO] --- maven-jar-plugin:3.0.2:jar (default-jar) @ repo ---
[INFO] Building jar: C:\Develop\IProjects\bpm\repo\target\repo-0.0.1-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------

[tbroyer]

OK, so I reproduce the issue with your repro-case, and I understand why it happens (I only moved the import-sources goal to process-classes in the gwt-app packaging, not the gwt-lib one).
…and it didn't get caught in the IT tests because the maven-compiler-plugin changes its behavior depending on the source configuration (which was left to its 1.5 default value) and won't pass a -s argument to JavaC, therefore writing the generated source files alongside the class files, so they were packaged in the JAR, generating a false positive for the verification script.

Workarounds above should apply, but I think I'll overhaul the whole sources processing (i.e. remove it) and use a custom jar goal: part of the rationale was that you could "filter" your sources by declaring them as resources too, but if you need that you should actually use the templating-maven-plugin to pre-process sources rather than post-process them. And with the proper processing order in that new goal I should be able to provide the same behavior as currently (when it works correctly) and avoid breaking the (hypothetical) projects that could use that feature.

[chris-becker]

Cool !
My current workaround is using the maven-processor-plugin to move annotation processing before import-sources (thanks, @ibaca ;):

  <plugin>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.6.0</version>
    <configuration>
      <proc>none</proc>
    </configuration>
  </plugin>
  <plugin>
    <groupId>org.bsc.maven</groupId>
    <artifactId>maven-processor-plugin</artifactId>
    <version>2.2.4</version>
    <executions>
      <execution>
        <goals>
          <goal>process</goal>
        </goals>
        <configuration>
          <outputDirectory>target/generated-sources/annotations</outputDirectory>
        </configuration>
      </execution>
    </executions>
  </plugin>

[tbroyer]

Test fixed in 9a599a1, code fixed in 8295cc1.
@chris-becker Would you mind testing with 1.0-SNAPSHOT? (available from the https://oss.sonatype.org/content/repositories/snapshots/ repository)

[chris-becker]

Works... !
Had to remove above workaround, though: While that's in place I get the sources, but not the generated classes in my lib ;)

[tbroyer]

FWIW, I finally did the refactoring suggested in #40 (comment) (shipped in 1.0-rc-7), though I forgot to take into account the source roots in the staleness check (this isn't a problem when editing a Java file, as it'll be recompiled, leading to an updated *.class file that will re-trigger the compilation; but it won't recompile if you change a non-Java file in a source root, such as a *.ui.xml file in src/main/java).

edit: fixed in 0507e6d