when mixing Scala and Java, scalac doesn't recognize unqualified name of inherited enum

[scabug]

compilation fails if all source files are passed to scalac:

  ~/newbug> cat I.java 
interface I { public enum E { E1 } }
  ~/newbug> cat J.java 
class J implements I {
	public void foo(E e) { }
}
  ~/newbug> cat S.scala 
object S { (new J).foo(null) }
  ~/newbug> ~/scala/dists/latest/bin/scalac I.java J.java S.scala 
J.java:2: error: not found: type E
	public void foo(E e) { }
                        ^
one error found

but succeeds if javac is run first:

  ~/newbug> javac *.java
  ~/newbug> ~/scala/dists/latest/bin/scalac S.scala

the bug is very easy to work around by writing out the name more fully:

  ~/newbug> cat J.java 
class J implements I {
	public void foo(I.E e) { }
}
  ~/newbug> ~/scala/dists/latest/bin/scalac I.java J.java S.scala

I'm running r15746.

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-1211?orig=1
Reporter: @SethTisue

[scabug]

@SethTisue said:
the bug is still present in 2.7.2.RC6.

[scabug]

@paulp said:
This is fixed in trunk.

[scabug]

John Sirois (jsirois) said:
This issue still exists, or exists in a very similar form in scalac 2.9.2:

$ scalac -version
Scala compiler version 2.9.2 -- Copyright 2002-2011, LAMP/EPFL
$ cat I.java 
abstract class I { public enum E { E1 } }
$ cat J.java 
class J extends I {
  public void foo(E e) { }
}
$ cat S.scala 
object S { (new J).foo(null) }
$ scalac I.java J.java S.scala
J.java:2: error: not found: type E
  public void foo(E e) { }
                  ^
one error found

The only changes from the initial bug example are s/interface/abstract class/ in I.java and scalac 2.9.2.

Things test fine when I is an interface. I have not checked the scalac 2.8 variable.

[scabug]

John Sirois (jsirois) said:
The issue exists in 2.10.1 as well:

$ cat I.java 
abstract class I { public enum E { E1 } }
$ cat J.java 
class J extends I {
  public void foo(E e) { }
}
$ cat S.scala 
object S { (new J).foo(null) }
$ ./bin/scalac -version
Scala compiler version 2.10.1 -- Copyright 2002-2013, LAMP/EPFL
$ ./bin/scalac I.java J.java S.scala 
J.java:2: error: not found: type E
  public void foo(E e) { }
                  ^
one error found

[scabug]

John Sirois (jsirois) said:
And finally this appears to have been an issue even with the initial fix - happy to file a new bug if thats helpful:

$ /opt/scala-2.8.0.final/bin/scalac -version
Scala compiler version 2.8.0.final -- Copyright 2002-2010, LAMP/EPFL
$ /opt/scala-2.8.0.final/bin/scalac I.java J.java S.scala 
J.java:2: error: not found: type E
  public void foo(E e) { }
                  ^
one error found

$ /opt/scala-2.8.2.final/bin/scalac -version
Scala compiler version 2.8.2.final -- Copyright 2002-2010, LAMP/EPFL
$ /opt/scala-2.8.2.final/bin/scalac I.java J.java S.scala 
J.java:2: error: not found: type E
  public void foo(E e) { }
                  ^
one error found

[scabug]

John Sirois (jsirois) said (edited on Apr 21, 2013 11:54:58 PM UTC):
The parser phase output for I.java as interface and abstract class give a clue (using scalac 2.10.1) - note the abstract class has no type forwarder for the enum:

Interface:

[[syntax trees at end of                    parser]] // I.java
package <empty> {
  private[<empty>] object I extends  {
    def <init>() = _;
    object E extends  {
      def <init>() = _;
      <stable> <static> val E1: E = _;
      <static> def values(): scala.Array[E] = _;
      <static> def valueOf(x: String): E = _
    };
    <static> class E extends _root_.java.lang.Enum[E] {
      import E._;
      def <init>() = _
    }
  };
  abstract private[<empty>] trait I extends _root_.java.lang.Object {
    import I._;
    def <init>() = _;
    protected type E = I.E
  }
}

Abstract class:

[[syntax trees at end of                    parser]] // I.java
package <empty> {
  private[<empty>] object I extends  {
    def <init>() = _;
    object E extends  {
      def <init>() = _;
      <stable> <static> val E1: E = _;
      <static> def values(): scala.Array[E] = _;
      <static> def valueOf(x: String): E = _
    };
    <static> class E extends _root_.java.lang.Enum[E] {
      import E._;
      def <init>() = _
    }
  };
  abstract private[<empty>] class I extends _root_.java.lang.Object {
    import I._;
    def <init>() = _
  }
}

[scabug]

John Sirois (jsirois) said:
Need to spend some time to add a test case - looks like test/files/jvm/nest.* is the right place, but simply adding forwarders for classes and interfaces seems like the right idea, certainly fixes this case:
{code}[jsirois@gill ~/dev/3rdparty/scala] (master *) $ git log -1
commit cde1c93197e85806a743ddbae190f2a78a43014e
Merge: 2e0cef0 47b626e
Author: Jason Zaugg [email protected]
Date: Sun Apr 21 15:04:26 2013 -0700

Merge pull request #2398 from huitseeker/silence_scaladoc_better

Change unrecognized scaladoc comments to C-style

[jsirois@gill ~/dev/3rdparty/scala] (master *) $ git diff
diff --git a/src/compiler/scala/tools/nsc/javac/JavaParsers.scala b/src/compiler/scala/tools/nsc/javac/JavaParsers.scala
index f1b1d1a..0603be4 100644
--- a/src/compiler/scala/tools/nsc/javac/JavaParsers.scala
+++ b/src/compiler/scala/tools/nsc/javac/JavaParsers.scala
@@ -732,7 +732,7 @@ trait JavaParsers extends ast.parser.ParsersCommon with JavaScanners {
}
}
def forwarders(sdef: Tree): List[Tree] = sdef match {

•    case ClassDef(mods, name, tparams, _) if (parentToken == INTERFACE) =>
  

•    case ClassDef(mods, name, tparams, _) if (parentToken == INTERFACE || parentToken == CLASS) =>
       val tparams1: List[TypeDef] = tparams map (_.duplicate)
       var rhs: Tree = Select(Ident(parentName.toTermName), name)
       if (!tparams1.isEmpty) rhs = AppliedTypeTree(rhs, tparams1 map (tp => Ident(tp.name)))
  

{code}

[scabug]

@soc said:
Is this by chance also related to the fact that nested enums are implicitly static?

[som-snytt]

We have a nice warning when selecting an element that appears to be a non-inherited Java static member.

It should warn if the element name pops up as a static in any of the interfaces selected from.

It doesn't warn for random symbol not found, however.

[SethTisue]

@som-snytt Thank you for fixing the bug I reported in 2008 (!!!)