SI-5568 Fixes verify error from getClass on refinement of value type

().asInstanceOf[AnyRef with Unit].getClass and
5.asInstanceOf[AnyRef with Int].getClass would cause a verify
error. Going the other way, i.e. [Unit with AnyRef] or [Int with AnyRef]
worked fine. This commit fixes it that both directions work out to
BoxedUnit or java.lang.Integer.

1 files changed, 17 insertions, 6 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala
index 7b9b13ae1c..58494cb18e 100644
--- a/src/compiler/scala/tools/nsc/transform/Erasure.scala
+++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala
@@ -340,12 +340,18 @@ abstract class Erasure extends AddInterfaces
       case _                               => tp.deconst
     }
   }
-  // Methods on Any/Object which we rewrite here while we still know what
-  // is a primitive and what arrived boxed.
-  private lazy val interceptedMethods = Set[Symbol](Any_##, Object_##, Any_getClass, AnyVal_getClass) ++ (
-    // Each value class has its own getClass for ultra-precise class object typing.
+  
+  // Each value class has its own getClass for ultra-precise class object typing.
+  private lazy val primitiveGetClassMethods = Set[Symbol](Any_getClass, AnyVal_getClass) ++ (
     ScalaValueClasses map (_.tpe member nme.getClass_)
   )
+  
+  // ## requires a little translation
+  private lazy val poundPoundMethods = Set[Symbol](Any_##, Object_##)
+  
+  // Methods on Any/Object which we rewrite here while we still know what
+  // is a primitive and what arrived boxed.
+  private lazy val interceptedMethods = poundPoundMethods ++ primitiveGetClassMethods
 
 // -------- erasure on trees ------------------------------------------
 
@@ -1136,7 +1142,7 @@ abstract class Erasure extends AddInterfaces
                   args)
               }
             } else if (args.isEmpty && interceptedMethods(fn.symbol)) {
-              if (fn.symbol == Any_## || fn.symbol == Object_##) {
+              if (poundPoundMethods.contains(fn.symbol)) {
                 // This is unattractive, but without it we crash here on ().## because after
                 // erasure the ScalaRunTime.hash overload goes from Unit => Int to BoxedUnit => Int.
                 // This must be because some earlier transformation is being skipped on ##, but so
@@ -1152,9 +1158,14 @@ abstract class Erasure extends AddInterfaces
               } else if (isPrimitiveValueClass(qual.tpe.typeSymbol)) {
                 // Rewrite 5.getClass to ScalaRunTime.anyValClass(5)
                 global.typer.typed(gen.mkRuntimeCall(nme.anyValClass, List(qual, typer.resolveClassTag(tree.pos, qual.tpe.widen))))
-              } else if (fn.symbol == AnyVal_getClass) {
+              } else if (primitiveGetClassMethods.contains(fn.symbol)) {
+                // if we got here then we're trying to send a primitive getClass method to 
+                // a) an Any, or
+                // b) a non-primitive, e.g. because the qualifier's type is a refinement type where part of the refinement is a primitive.
+                // if we use Object_getClass then things work out because we will call getClass on the boxed form of the Any or primitive
                 tree setSymbol Object_getClass
               } else {
+                debugwarn(s"The symbol '${fn.symbol}' was interecepted but didn't match any cases, that means the intercepted methods set doesn't match the code")
                 tree
               }
             } else qual match {