Can AbstractProcessor detect if annotated method has compilation errors?

My AbstractProcessorimplementation gets called even though the annotated method contains code that results in compiler errors. (I.e. the processor is triggered by the presence of an annotation whose target is ElementType.METHOD).

Having experimented a bit I get the impression that syntax errors in the method body results in the AbstractProcessor not being triggered, whereas "reference errors", fx trying to call a private method that can't be reached, does result in the AbstractProcessor being called.

I am glad that the AbstractProcessor is being called, but I need to know if the annotated method contains any errors.

I have two questions:

1. How can my AbstractProcessor code know, if the ExecutableElement my method is found on, contains errors? I am aware of Google Auto's SuperficialValidation, but I can't get it to detect these errors - perhaps it only works on TypeElements?
2. Can I be sure that all compiler versions have the same behavior with regards to with kinds of errors prevents the AbstractProcessor from being called, and which ones will let it perform its logic?

The JavaCompiler has multiple phases that run.
You can see if the processing is complete from the RoundEnvironment.processingOver() and walk the tree using a TreePathScanner.
However a lot of the actual errors are found after annotation processing is complete and can be found in the diagnostics. You might be able to find some information by supplying a DiagnosticListener.

There are some ways to detect that an error has occurred from inspecting the Symbol/Type of the symbol.
Using a TreePathScanner inside the visitMethodInvocatio you would expect the symbol to be a method, but if that method doesn't exist it may be null or a ClassSymbol.