Disallowed super.XX calls to Any methods which ...

Disallowed super.XX calls to Any methods which are presently either
crashing the compiler (isInstanceOf) or leading to runtime failure (==
and !=) in addition to one which was being rewritten to a this call but
makes more sense disallowed like the others (##).

Closes #3736, review by odersky.

1 files changed, 10 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala b/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala
index 541ef35b4b..16c6203474 100644
--- a/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala
@@ -80,11 +80,6 @@ abstract class SuperAccessors extends transform.Transform with transform.TypingT
       }
 
     private def transformSuperSelect(tree: Tree): Tree = tree match {
-      // Intercept super.## and translate it to this.##
-      // which is fine since it's final.
-      case Select(sup @ Super(_, _), nme.HASHHASH)  =>
-        Select(gen.mkAttributedThis(sup.symbol), Object_##) setType IntClass.tpe
-
       case Select(sup @ Super(_, mix), name)  =>
         val sym = tree.symbol
         val clazz = sup.symbol
@@ -127,6 +122,13 @@ abstract class SuperAccessors extends transform.Transform with transform.TypingT
         tree
     }
 
+    // Disallow some super.XX calls targeting Any methods which would
+    // otherwise lead to either a compiler crash or runtime failure.
+    private def isDisallowed(name: Name) = name match {
+      case nme.HASHHASH | nme.EQ | nme.NE | nme.isInstanceOf_ => true
+      case _                                                  => false
+    }
+
     override def transform(tree: Tree): Tree = {
       val sym = tree.symbol
 
@@ -203,6 +205,9 @@ abstract class SuperAccessors extends transform.Transform with transform.TypingT
             unit.error(tree.pos, "super may be not be used on "+
                        (if (sym.hasFlag(ACCESSOR)) sym.accessed else sym))
           }
+          else if (isDisallowed(name)) {
+            unit.error(tree.pos, "super not allowed here: use this." + name.decode + " instead")
+          }
           transformSuperSelect(tree)
 
         case TypeApply(sel @ Select(qual, name), args) =>