Fields on parceler breaks Incremental annotation processor.

[doniwinata0309]

Hi, i found some cases where parceler breaks the incremental compilation.
I have sample project for this issue:

Parceler-test.zip

There are 3 modules: app (application module), depends to: basemodule and mylibrary1.

Supposed on basemodule we have these:

package com.test.basemodule;

import org.parceler.Parcel;

@Parcel
public class FieldClassParcel {
}

and

import org.parceler.Parcel;

@Parcel
public class BaseClassParcel {
    //it working fine if private, but protected will cause all files recompiled
    protected FieldClassParcel testField;
}

Those two class used on app module:

public class ExampleParcel extends BaseClassParcel {

    private final String message;

    @ParcelFactory
    public static ExampleParcel create(String message) {
        return new ExampleParcel(message);
    }

    public ExampleParcel(String message) {
        this.message = message;
    }

    public String getMessage(){
        return message;
    }
}

Those classes will breaks incremental annotation processor on app module.

Step to repro:

1. Unzip and open the project.
2. Run clean build (./gradlew clean app:assembleD)
3. Change public ABI on LibClass.java

    public void method1changed2(){

    }
    //uncomment this for test public ABI change (incremental), or change the method name `method1`)

//    public void method2(){
//
//    }
}

4. Run the project and print the compiled class during kapt process with this command:
   ./gradlew app:assembleD --debug --Pkapt.verbose=true > log1.txt

5. The result should be similar with file: incremental-test1.txt on attached file.
   the part i: [kapt] Java source files: on module app should contains lot of files.

6. Change BaseClassParcel field to private

public class BaseClassParcel {
    //it working fine if private, but protected will cause all files recompiled
    private FieldClassParcel testField;
}

7. clean the project, and repeat step 1-5. The result of this test will be similar to incremental-test2.txt. the part i: [kapt] Java source files: should be empty in this test.

The files that recompile will be all java source file in the module, including another annotation processor. For a module with large annotated files it taking so long to build.

Hopefully this is clear enough to explain our issue, let me know if you need additional information.
Thanks.

[doniwinata0309]

I also reporting here:
https://youtrack.jetbrains.com/issue/KT-34340
we can use kotlin 1.3.70 to spot the files that causing full recompilation.

Seems to be those classes always extending the class from another module, and generating:
$$PackageHelper. This fails the incremental compilation.

[John Ericksen]

Hmm, any ideas on a fix?

[doniwinata0309]

I manage to fix this by moving affected class into the same module, or change the field into public (instead protected).