SI-8926 default visbility RUNTIME for java annotations

When parsed from source, java annotation class symbol are lacking the
`@Retention` annotation. In mixed compilation, java annotations are
therefore emitted with visibility CLASS.

This patch conservatively uses the RUNTIME visibility in case there is
no @Retention annotation.

The real solution is to fix the Java parser, logged in SI-8928.

1 files changed, 11 insertions, 4 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeAsmCommon.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeAsmCommon.scala
index 4285858bf8..fc01f89580 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeAsmCommon.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeAsmCommon.scala
@@ -19,7 +19,7 @@ final class BCodeAsmCommon[G <: Global](val global: G) {
   val ExcludedForwarderFlags = {
     import scala.tools.nsc.symtab.Flags._
     // Should include DEFERRED but this breaks findMember.
-    ( SPECIALIZED | LIFTED | PROTECTED | STATIC | EXPANDEDNAME | BridgeAndPrivateFlags | MACRO )
+    SPECIALIZED | LIFTED | PROTECTED | STATIC | EXPANDEDNAME | BridgeAndPrivateFlags | MACRO
   }
 
   /**
@@ -147,9 +147,16 @@ final class BCodeAsmCommon[G <: Global](val global: G) {
       annot.args.isEmpty
   }
 
-  def isRuntimeVisible(annot: AnnotationInfo): Boolean =
-    annot.atp.typeSymbol.getAnnotation(AnnotationRetentionAttr)
-      .exists(_.assocs.contains((nme.value -> LiteralAnnotArg(Constant(AnnotationRetentionPolicyRuntimeValue)))))
+  def isRuntimeVisible(annot: AnnotationInfo): Boolean = {
+    annot.atp.typeSymbol.getAnnotation(AnnotationRetentionAttr) match {
+      case Some(retentionAnnot) =>
+        retentionAnnot.assocs.contains(nme.value -> LiteralAnnotArg(Constant(AnnotationRetentionPolicyRuntimeValue)))
+      case _ =>
+        // SI-8926: if the annotation class symbol doesn't have a @RetentionPolicy annotation, the
+        // annotation is emitted with visibility `RUNTIME`
+        true
+    }
+  }
 
   private def retentionPolicyOf(annot: AnnotationInfo): Symbol =
     annot.atp.typeSymbol.getAnnotation(AnnotationRetentionAttr).map(_.assocs).map(assoc =>