Instruments are used to track runtime events to allow for profiling, debugging and other kinds of behavior analysis at runtime.
Every Instrument must be implemented in Java and have name that ends with
Instrument. This requirement is to ensure that the fix
described below works.
Annotations are used to register the implemented instruments with Graal. The annotation processor is triggered when recompiling the Java files. Unfortunately, when doing an incremental compilation, only the changed files are recompiled and the annotation processor ‘forgets’ about other instruments that haven’t been recompiled, leading to runtime errors about missing instruments.
To fix that, we add the
task which detects changes to any of the instruments and forces recompilation of
all instruments in the project by removing their classfiles.