Maven Compiler Plugin should add to compileSourceRoots for next plugins to consider as source directory for generated files

One obvious workaround would be using build helper plugin to add the target/generated-sources/annotations to source path, like:

 
<build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>build-helper-maven-plugin</artifactId>
        <version>1.7</version>
        <executions>
          <execution>
            <id>add-source</id>
            <phase>generate-sources</phase>
            <goals>
              <goal>add-source</goal>
            </goals>
            <configuration>
              <sources>
                <source>target/generated-sources/annotations</source>
              </sources>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

Hi, I have tried to above workaround, but it does not work.

Here is the link to the StackOverflow question I created earlier today: http://stackoverflow.com/questions/6975298/generated-code-not-taken-into-account-in-maven-compile-process.

To be more precise, when I apply the workaround to the provided test case, it works. Yet, in my application, it does not work. The only difference is that I generate a java file where only a .aj file is generated in the test case.

I have performed some tests and here are my results:

i) I have checked-out maven-compiler-plugin from the 2.3.3 release locally
ii) I have applied the patch provided by Zoran
iii) I confirm that the issue he reported is solved with this patch (and it does not break existing tests)
iv) However, when generating a java file instead of an aspectj file, the java file is not taken into account in the compiling process (it is not part of the generated .jar)

I am posting another test case to illustrate my point. Keep in mind that I am new to annotation processing, so I may miss something obvious.

Sorry, I meant 2.3.2 release.

For that matter, why not also add the generated sources directory to the sourcepath as well, so that it gets compiled in the same run? The attached patch (maven-compiler-plugin-addToSourcePathAsWell.patch) builds on the original one to do that.

maven-compiler-plugin-addToSourcePathAsWell.patch should not be necessary to my knowledge; 269-generated sources already get compiled in the same run.

I managed to get this working using the helper plugin in combination with a second invocation of the compiler.

Let compiler run normally and generate the annotation processor output.

Then invoke the help plugin at the process-classes lifecycle stage, followed by the compiler again.

Note that the order is important, so that the build-helper gets invoked before the compiler.

<plugins>

<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>build-helper-maven-plugin</artifactId>
<version>1.7</version>
<executions>
<execution>
<id>add-source</id>
<phase>process-classes</phase>
<goals>
<goal>add-source</goal>
</goals>
<configuration>
<sources>
<source>target/generated-sources/annotations</source>
</sources>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<executions>
<execution>
<id>add-source</id>
<phase>process-classes</phase>
<goals>
<goal>compile</goal>
</goals>

</execution>
</executions>
</plugin>
</plugins>

Should also state I upgraded to the compiler version 2.5.1 and am using maven 3.0.4

is there any way to have a failing test case ?

Olivier, so the two projects that I'll upload are example of a failing situation. The awkwardly named compiler-plugin-simple-annotation-processor is an annotation processor that will generate a .txt file in the with the same directory structure as the annotated class, that is a class annotated with @SimpleAnnotation. The other project is compiler-plugin-annotation-test that has a compile dependency on the former, and a test that checks if the .txt file was indeed created.

If you were to do it on command line using standard java tools you would first compile the sources with javac (including compiler-plugin-simple-annotation-processor.jar and junit.jar) at this point javac would detect the annotation processor and it would create the .txt file (in current directory if no -s option was given). Then you would use java org.junit.runner.JUnitCore org.apache.maven.plugin.AnnotationProcessorTest with classpath pointing to the output of javac (that would include the generated .txt file).

With maven project directory structure and conventions, i.e. source output of annotation processors is target/generated-sources/[test-]annotations, and the fact that current maven compiler plugin does not forward the target/generated-sources/[test-]annotations to compileSourceRoots fails the test. The build helper workaround mentioned above helps, but I think that proper solution is for maven compiler plugin to include the sources it generated (via annotation processors) in classpath for other plugins to have.

This is very similar to my original use case - in which I was generating resources (AspectJ inter type declarations) to be considered by the another plugin after maven compiler plugin (AspectJ maven plugin), that needs these generated resources in classpath. But I imagine that there are other use cases for this as well.

I don't know it this is what you were thinking by a failing test, but I hope it helps.

Zoran

The failing test example