Incremental java compilation fails when renaming classname with $ character

[horseunnamed]

Issue occurs since Gradle 7.3. Tested with OpenJDK 11 and 13. Tiny reproduction sample is here: https://github.com/horseunnamed/Gradle-change-detection-issue

Expected Behavior

Incremental java compilation is successful when classname with $ is renamed (as it is with Gradle 7.2 and earlier versions)

Current Behavior

After changing java class name with $ character and running incremental build we get the error:

> Task :compileJava FAILED
Caching disabled for task ':compileJava' because:
  Build cache is disabled
Task ':compileJava' is not up-to-date because:
  Input property 'stableSources' file .../src/main/java/issue/Class$Name.java has been removed.
  Input property 'stableSources' file .../src/main/java/issue/Main.java has changed.
  Input property 'stableSources' file .../src/main/java/issue/Class$NameChanged.java has been added.
Created classpath snapshot for incremental compilation in 0.0 secs.
Compiling with toolchain '/Library/Java/JavaVirtualMachines/openjdk-11.0.2.jdk/Contents/Home'.
Compiling with JDK Java compiler API.
.../src/main/java/issue/Main.java:5: error: cannot find symbol
        new Class$NameChanged();
            ^
  symbol:   class Class$NameChanged
  location: class Main
1 error
Incremental compilation of 3 classes completed in 0.012 secs.
:compileJava (Thread[Execution worker for ':',5,main]) completed. Took 0.02 secs.

FAILURE: Build failed with an exception.

Context

On our real world Android-project we had a very harmful impact from this issue when upgrading Gradle version to 7.3.1.
Incremental annotation processor in our project generates some files with dollar sign and this issue silently led us to ClassNotFoundException at runtime in some cases.
It's very serious blocker for us to upgrade from 7.2.

Steps to Reproduce

Please see reproduction sample: https://github.com/horseunnamed/Gradle-change-detection-issue

1. Run build task to compile java project with classname that conatins dollar sign (e.g. Class$Name.java) and reference to it somewhere else (from Main.java in my reproduction sample)
2. Change classname and reference to it with something that still contains dollar sign
3. Rerun build task
4. Get mentioned incremental compilation error

Your Environment

Build scan of failed incremental build from reproduction sample: https://scans.gradle.com/s/b4qlo2umn7dms

[asodja]

@horseunnamed PR with the fix will be merged soon. Can you maybe share the name of the annotation processor? Is this some popular annotation processor in the Android world?

We would like to find out how many users might be affected by this issue.

[horseunnamed]

@asodja, thanks for fixing this issue so quickly!
On real project we faced this issue with annotation processor from Toothpick library.
I also have a more complex reproducer with annotation processor from Toothpick. It's very close to our real project issue. See README from this sample for details.

[asodja]

Thank you for that info. Note that the fix is already on the latest nightly. Can you maybe try it and confirm that that fixes the issue? Here is the info on how you can update the wrapper: https://gradle.org/nightly/

[horseunnamed]

I've tried to reproduce this issue on our real project with latest nightly build and can confirm that issue was fixed :)
Thanks again!