RFR: JDK-8234101: Compilation error thrown when repeating annotation is used on record component

[Vicente Romero]

Hi,

Please review the fix for [1] at [2]. This patch provides support for 
repeating annotations on records. It builds on the previous support for 
annotations for records. Which is that all annotations applied to record 
components are pushed down to all members generated by the compiler from 
each record component: field, constructor parameter and accessor. Later 
at Check::validateAnnotation if we have gone too far and had applied an 
annotation to a non-applicable location, it is removed.

The idea of this patch is that when a repeated annotations are being 
processed at Annotate::processRepeatedAnnotations, if the annotated 
element is a record or a record member and the annotation is not 
applicable to it, we bail out instead of issuing an error. Later on at 
Check::validateAnnotation when we have all the information about the 
annotations we can remove non-applicable annotations as before. But 
there is an important detail Check::validateAnnotation, validates 
annotations one by one, so if an annotation has been repeated kind of:

record R(@A @A int i) {}

then the method will be invoked twice for each appearance of @A, 
currently Check::validateAnnotation can remove each instance, but we 
also want to remove the container annotation which is synthetically 
generated by javac. For this reason I have modified 
SymbolMetadata::remove to remove a container annotation if at least one 
of the contained annotations is removed. How does it looks?

Thanks,
Vicente

[1] https://bugs.openjdk.java.net/browse/JDK-8234101
[2] http://cr.openjdk.java.net/~vromero/8234101/webrev.00/