'class file is broken' error when extending Java static inner classes

[scabug]

The Scala compiler gives an erroneous 'class file broken' error when trying to use classes that inherit from static Java inner classes. This is particularly a problem when integrating with Java code generated by the [http://incubator.apache.org/thrift/ Apache Thrift] compiler. Below are the files and steps needed to reproduce the problem.

!ClassOne.java:

public class ClassOne {
	public interface Iface {
		public void func1();
	}
	public static class Child implements Iface {
		public void func1() {return ;}
	}
}

!ClassTwo.java:

public class ClassTwo {
	public interface Iface extends ClassOne.Iface  {
		public void func2();
	}
	public static class Child extends ClassOne.Child implements Iface {
		public void func2() {return ;}
	}
}

!ScalaClasses.scala:

class ScalaClassOne extends ClassTwo.Child {
	def func4() = {
		func1
		func2
	}	
}

class ScalaClassTwo extends ClassTwo.Iface {
	def func1() = null
	def func2() = null
}

Bug.scala:

object Test {
	val c2 = new ScalaClassTwo
	val c1 = new ScalaClassOne
}

And the following compilation sequence:

	javac *.java
	scalac ScalaClasses.scala
	scalac Bug.scala

The compilation of Bug.scala will fail with the following error on 2.7.5:

error: error while loading ScalaClassOne, class file './ScalaClassOne.class' is broken
(package <empty> does not have a member ClassThree$$Child)
User.scala:3: error: ScalaClassOne does not have a constructor
	val c1 = new ScalaClassOne
                 ^
two errors found

And this error on 2.8.0-b20090919135825:

scala.tools.nsc.FatalError: package <empty> does not have a member ClassTwo$$Child
	at scala.tools.nsc.symtab.Definitions$$definitions$$.getMember(Definitions.scala:406)
	at scala.tools.nsc.symtab.classfile.ClassfileParser.lookupClass$$1(ClassfileParser.scala:382)
	at scala.tools.nsc.symtab.classfile.ClassfileParser.classNameToSymbol(ClassfileParser.scala:394)
	at scala.tools.nsc.symtab.classfile.ClassfileParser$$ConstantPool.getClassSymbol(ClassfileParser.scala:180)
	at scala.tools.nsc.symtab.classfile.ClassfileParser$$ConstantPool.getSuperClass(ClassfileParser.scala:317)
	at scala.tools.nsc.symtab.classfile.ClassfileParser.parseClass(ClassfileParser.scala:415)
	at scala.tools.nsc.symtab.classfile.ClassfileParser.parse(ClassfileParser.scala:92)
	at scala.tools.nsc.symtab.SymbolLoaders$$ClassfileLoader$$$$anonfun$$doComplete$$4.apply(SymbolLoaders.scala:291)
	at scala.tools.nsc.symtab.SymbolLoaders$$ClassfileLoader$$$$anonfun$$doComplete$$4.apply(SymbolLoaders.scala:291)
	at scala.tools.nsc.symtab.SymbolLoaders.completeClassfile(SymbolLoaders.scala:278)
	at scala.tools.nsc.symtab.SymbolLoaders$$ClassfileLoader.doComplete(SymbolLoaders.scala:290)
	at scala.tools.nsc.symtab.SymbolLoaders$$SymbolLoader.complete(SymbolLoaders.scala:55)
	at scala.tools.nsc.symtab.SymbolLoaders$$SymbolLoader.load(SymbolLoaders.scala:75)
	at scala.tools.nsc.symtab.Symbols$$Symbol.exists(Symbols.scala:600)
	at scala.tools.nsc.typechecker.Typers$$Typer.qualifies$$1(Typers.scala:3316)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedIdent$$1(Typers.scala:3332)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed1(Typers.scala:3697)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3768)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedTypeConstructor(Typers.scala:3866)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedTypeConstructor(Typers.scala:3874)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedNew$$1(Typers.scala:2854)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed1(Typers.scala:3599)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3768)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedQualifier(Typers.scala:3835)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed1(Typers.scala:3685)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3768)
	at scala.tools.nsc.typechecker.Typers$$Typer$$$$anonfun$$typedApply$$1$$1.apply(Typers.scala:3045)
	at scala.tools.nsc.typechecker.Typers$$Typer$$$$anonfun$$typedApply$$1$$1.apply(Typers.scala:3045)
	at scala.tools.nsc.typechecker.Typers$$Typer.silent(Typers.scala:698)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedApply$$1(Typers.scala:3045)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed1(Typers.scala:3663)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3768)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3826)
	at scala.tools.nsc.typechecker.Typers$$Typer.computeType(Typers.scala:3877)
	at scala.tools.nsc.typechecker.Namers$$Namer.typeSig(Namers.scala:1141)
	at scala.tools.nsc.typechecker.Namers$$Namer$$$$anonfun$$typeCompleter$$1.apply(Namers.scala:509)
	at scala.tools.nsc.typechecker.Namers$$Namer$$$$anonfun$$typeCompleter$$1.apply(Namers.scala:507)
	at scala.tools.nsc.typechecker.Namers$$$$anon$$1.complete(Namers.scala:1288)
	at scala.tools.nsc.symtab.Symbols$$Symbol.info(Symbols.scala:728)
	at scala.tools.nsc.symtab.Symbols$$Symbol.initialize(Symbols.scala:837)
	at scala.tools.nsc.symtab.Symbols$$Symbol.annotations(Symbols.scala:111)
	at scala.tools.nsc.typechecker.Typers$$Typer.addGetterSetter(Typers.scala:1277)
	at scala.tools.nsc.typechecker.Typers$$Typer$$$$anonfun$$10.apply(Typers.scala:1385)
	at scala.tools.nsc.typechecker.Typers$$Typer$$$$anonfun$$10.apply(Typers.scala:1385)
	at scala.collection.TraversableLike$$$$anonfun$$flatMap$$1.apply(TraversableLike.scala:167)
	at scala.collection.TraversableLike$$$$anonfun$$flatMap$$1.apply(TraversableLike.scala:167)
	at scala.collection.LinearSequenceLike$$class.foreach(LinearSequenceLike.scala:85)
	at scala.collection.immutable.List.foreach(List.scala:27)
	at scala.collection.TraversableLike$$class.flatMap(TraversableLike.scala:167)
	at scala.collection.immutable.List.flatMap(List.scala:27)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedTemplate(Typers.scala:1385)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedModuleDef(Typers.scala:1256)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed1(Typers.scala:3498)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3768)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3813)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedStat$$1(Typers.scala:1815)
	at scala.tools.nsc.typechecker.Typers$$Typer$$$$anonfun$$20.apply(Typers.scala:1872)
	at scala.tools.nsc.typechecker.Typers$$Typer$$$$anonfun$$20.apply(Typers.scala:1872)
	at scala.collection.immutable.List.loop$$2(List.scala:123)
	at scala.collection.immutable.List.mapConserve(List.scala:140)
	at scala.tools.nsc.typechecker.Typers$$Typer.typedStats(Typers.scala:1872)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed1(Typers.scala:3491)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3768)
	at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3813)
	at scala.tools.nsc.typechecker.Analyzer$$typerFactory$$$$anon$$2.apply(Analyzer.scala:57)
	at scala.tools.nsc.Global$$GlobalPhase.applyPhase(Global.scala:329)
	at scala.tools.nsc.typechecker.Analyzer$$typerFactory$$$$anon$$2$$$$anonfun$$run$$1.apply(Analyzer.scala:51)
	at scala.tools.nsc.typechecker.Analyzer$$typerFactory$$$$anon$$2$$$$anonfun$$run$$1.apply(Analyzer.scala:51)
	at scala.collection.Iterator$$class.foreach(Iterator.scala:525)
	at scala.collection.mutable.ListBuffer$$$$anon$$1.foreach(ListBuffer.scala:281)
	at scala.tools.nsc.typechecker.Analyzer$$typerFactory$$$$anon$$2.run(Analyzer.scala:51)
	at scala.tools.nsc.Global$$Run.compileSources(Global.scala:799)
	at scala.tools.nsc.Global$$Run.compile(Global.scala:882)
	at scala.tools.nsc.Main$$.process(Main.scala:91)
	at scala.tools.nsc.Main$$.main(Main.scala:105)
	at scala.tools.nsc.Main.main(Main.scala)
error: fatal error: package <empty> does not have a member ClassTwo$$Child
make: *** [all] Error 1

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-2464?orig=1
Reporter: Michael Armbrust (marmbrus)
Attachments:

• mini-vaadin.zip (created on Feb 24, 2013 7:46:52 PM UTC, 1609 bytes)
• tiny-vaadin.tar.bz2 (created on May 2, 2013 10:34:18 AM UTC, 3020483 bytes)

[scabug]

@dragos said:
(In r19874) Fixed ticket 2464

[scabug]

@dragos said:
(In r19945) Closed #2726 and added test for #2464 (refs #2464)

[scabug]

@paulp said:
My new officemates ran into this bug, also as a consequence of code generated by thrift. The test case given in this ticket works, but the bug is definitely still in trunk. I will work on getting a reproduction but please trust me for the moment. BTW incredibly I overlooked this ticket while researching this exact issue, because there are something like a dozen open or should-be-open tickets relating to inner classes.

I am going on a bytecode-tool-writing kick right now. Reconciling all the java and scala factors in the tricky interdependent attribute areas like InnerClasses is simply too hard. We're not going to get it right without validating the result.

[scabug]

@paulp said:
See #2896 for what should be a concrete example of this (or failing that, something similar.)

[scabug]

@paulp said:
...and also #2940.

[scabug]

Brian Hsu (brianhsu) said:
Just FYI, I think the following is another concrete example of this bug (or similar to this, I'm not very sure).

This is a code that use Google Mpas API in Android. In Google Maps API, MapView class has a static inner class witch extends from android.view.ViewGroup.LayoutParams which in turns another static inner class of ViewGroup.

Here is the sample code:

import android.os.Bundle
import android.widget.LinearLayout

import com.google.android.maps.MapActivity
import com.google.android.maps.MapView

class TestMap extends MapActivity
{
    type F = MapView.LayoutParams  // This will caused compiler crash
    override def isRouteDisplayed () = false

    override def onCreate(savedInstanceState: Bundle)
    {
        val mapView: MapView = null // This line also crash compiler
    }
}

When using the following commands to compile

/opt/scala-svn/bin/scalac -cp android.jar:maps.jar Test.scala

The compiler will complain

error: error while loading MapView, Missing dependency 'class android.view.ViewGroup$$LayoutParams', required by /opt/android-sdk-update-manager/add-ons/google_apis-7_r01/libs/maps.jar(com/google/android/maps/MapView.class)
error: error while loading LayoutParams, Missing dependency 'class android.view.ViewGroup$$LayoutParams', required by /opt/android-sdk-update-manager/add-ons/google_apis-7_r01/libs/maps.jar(com/google/android/maps/MapView$$LayoutParams.class)
two errors found

The scala compiler version is svn trunk at 2010-03-26

[scabug]

papamitra said:

Maybe maps.jar (Google Maps API in Android) is broken.
Because it seems that maps.jar in Android SDK is created by "mkstubs" in Android source tree(development/tools/mkstubs)

And, it writes in mkstubs's README.txt,

The generated constructors are not proper. They do not invoke the matching super() before the generated throw exception. Any attempt to load such a class should trigger an error from the byte code verifier or the class loader.

I replace MapView.class and MapController.class in maps.jar with the following files.

http://gist.github.com/454723
http://gist.github.com/454727

And, work it.

[scabug]

@paulp said:
Replying to [comment:16 papamitra]:

The generated constructors are not proper. They do not invoke the matching super() before the generated throw exception. Any attempt to load such a class should trigger an error from the byte code verifier or the class loader.

Well that's an interesting thing to find out at this stage of the game. Thanks. But even if we exclude maps.jar from consideration there are other examples of the issue with no such excuse.

[scabug]

@michelou said:
Case 1 (from marmbrus) is ok with 2.8.0.final.

Case 2 (from brianhsu) is fixed in rev22630. That case did in particular affect Android code (I had myself to disable Android examples such as MapsDemo, Wiktionary, Panoramio, WindWaves, see rev22631).

[scabug]

Stefan Endrullis (xylo) said (edited on Feb 24, 2013 7:50:14 PM UTC):
I know this bug is already 2 years old. However, today I got the same error or at least a very similar one using the Scala 2.10.0 and Scala 2.10.1-RC1 compiler:
error: error while loading com.vaadin.ui., class file '/home/stefan/.m2/repository/com/vaadin/vaadin/6.8.8/vaadin-6.8.8.jar(com/vaadin/ui/ClientWidget$LoadStyle.class)' is broken

It's easy to reproduce. I bundled a tiny example project into the attached zip archive. To compile it just run
$ mvn compile

The only Scala file included in the project is a one-liner:
class PortalLayout extends org.vaadin.sasha.portallayout.PortalLayout

Obviously it's not even necessary to refer to the "broken" class directly in the Scala code in order to let the compiler fail. And there is unfortunately nothing I can do to work around this except to avoid the class org.vaadin.sasha.portallayout.PortalLayout in my project completely.

Regards,
Stefan

[scabug]

Stefan Endrullis (xylo) said (edited on Apr 25, 2013 4:15:48 PM UTC):
Same in 2.10.1 and 2.11.0-M2. The Scala compiler fails to compile the vaadin project (attached).

Scala seems to be no longer compatible with vaadin. That's very disappointing. :(

[scabug]

@paulp said:
Stefan, I'll make you a deal - I fixed the bug you're hitting, but I do not have time to dredge out a test case. If you can manage the test case (no maven, no downloading giant jars - small self-contained java and scala) you'll see this fixed in 2.10.2.

Here's the code part: https://github.com/paulp/scala/tree/issue/2464

[scabug]

John Nestor (nestorpersist) said:
I am not sure about building a test case without the Vaadin jar.
Although the best guess is that Java inner classes are involved I don't know how to easily extract
all the potentially problematic code out of Vaadin.

If you have a fix I would be happy to try out your snapshot scala compiler with the fix on my project if you can make it available.