Ensure ClassBTypes constructed from symbol and classfile are identical

A super call (invokespecial) to a default method T.m is only allowed if
the interface T is a direct parent of the class. Super calls are
introduced for example in Mixin when generating forwarder methods:

    trait T { override def clone(): Object = "hi" }
    trait U extends T
    class C extends U

The class C gets a forwarder that invokes T.clone(). During code
generation the interface T is added as direct parent to class C. Note
that T is not a (direct) parent in the frontend type of class C.

This commit stores interfaces that are added to a class during code
generation in the InlineInfo classfile attribute. This allows filtering
the interface list when constructing a ClassBType from a classfile.

1 files changed, 1 insertions, 13 deletions

diff --git a/test/junit/scala/tools/nsc/backend/jvm/opt/BTypesFromClassfileTest.scala b/test/junit/scala/tools/nsc/backend/jvm/opt/BTypesFromClassfileTest.scala
index 1ce913006d..9e6a148dba 100644
--- a/test/junit/scala/tools/nsc/backend/jvm/opt/BTypesFromClassfileTest.scala
+++ b/test/junit/scala/tools/nsc/backend/jvm/opt/BTypesFromClassfileTest.scala
@@ -67,19 +67,7 @@ class BTypesFromClassfileTest {
     // there's a separate InlineInfoTest.
 
     val chk1 = sameBTypes(fromSym.superClass, fromClassfile.superClass, checked)
-    
-    // was:
-    // val chk2 = sameBTypes(fromSym.interfaces, fromClassfile.interfaces, chk1)
-
-    // TODO: The new trait encoding emits redundant parents in the backend to avoid linkage errors in invokespecial
-    // Need to give this some more thought, maybe do it earlier so it is reflected in the Symbol's info, too.
-    val fromSymInterfaces = fromSym.interfaces
-    val fromClassFileInterfaces = fromClassfile.interfaces
-    val (matching, other) = fromClassFileInterfaces.partition(x => fromSymInterfaces.exists(_.internalName == x.internalName))
-    val chk2 = sameBTypes(fromSym.interfaces, matching, chk1)
-    for (redundant <- other) {
-      assert(matching.exists(x => x.isSubtypeOf(redundant).orThrow), redundant)
-    }
+    val chk2 = sameBTypes(fromSym.interfaces, fromClassfile.interfaces, chk1)
 
     // The fromSym info has only member classes, no local or anonymous. The symbol is read from the
     // Scala pickle data and only member classes are created / entered.