Aladdin - Scala Bugtracking
[#728] project: compiler priority: low category: bug
submitter assigned to status date submitted
Sean Martin fixed 2006-09-05 10:44:09.0
subject extending type variable still causes compiler crash
code 
trait TestA {
  type Node <: NodeImpl;
  trait NodeImpl;
}

trait TestB extends TestA {
  type Node <: NodeImpl;
  trait NodeImpl extends super.Node;
  type Init <: Node with InitImpl;
  trait InitImpl extends NodeImpl;
}
what happened 
test/Test.scala:4 error: illegal cyclic reference involving trait NodeImpl
  type Node <: NodeImpl;
       ^
test/Test.scala:5 error: class type expected
  trait NodeImpl extends super.Node;
                              ^
test/Test.scala:5 error: illegal cyclic reference involving trait NodeImpl
  trait NodeImpl extends super.Node;
  ^
Exception in thread "main" java.lang.NullPointerException
	at scala.tools.nsc.symtab.Types$CompoundType.computeClosure$0(Types.scala:660)
	at scala.tools.nsc.symtab.Types$CompoundType.closure(Types.scala:709)
	at scala.tools.nsc.symtab.Symbols$Symbol.closureLength$0(Symbols.scala:491)
	at scala.tools.nsc.symtab.Symbols$Symbol.isLess(Symbols.scala:494)
	at scala.tools.nsc.symtab.Types$Type.closurePos(Types.scala:316)
	at scala.tools.nsc.symtab.Types$CompoundType.baseType(Types.scala:759)
	at scala.tools.nsc.symtab.Types$TypeRef.baseType(Types.scala:879)
	at scala.tools.nsc.symtab.Types$class.isSubType0(Types.scala:1725)
	at scala.tools.nsc.symtab.SymbolTable.isSubType0(SymbolTable.scala:10)
	at scala.tools.nsc.symtab.Types$class.isSubType(Types.scala:1681)
	at scala.tools.nsc.symtab.SymbolTable.isSubType(SymbolTable.scala:10)
	at scala.tools.nsc.symtab.Types$Type.$less$colon$less(Types.scala:256)
	at scala.tools.nsc.symtab.Types$$anonfun$27.apply(Types.scala:1754)
	at scala.tools.nsc.symtab.Types$$anonfun$27.apply(Types.scala:1754)
	at scala.List.forall(List.scala:822)
	at scala.tools.nsc.symtab.Types$class.isSubType0(Types.scala:1754)
	at scala.tools.nsc.symtab.SymbolTable.isSubType0(SymbolTable.scala:10)
	at scala.tools.nsc.symtab.Types$class.isSubType(Types.scala:1681)
	at scala.tools.nsc.symtab.SymbolTable.isSubType(SymbolTable.scala:10)
	at scala.tools.nsc.symtab.Types$Type.$less$colon$less(Types.scala:256)
	at scala.tools.nsc.typechecker.Typers$Typer.typedAbsTypeDef(Typers.scala:857)
	at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:1490)
	at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:1815)
	at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:1842)
	at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$48.apply(Typers.scala:1024)
	at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$48.apply(Typers.scala:1013)
	at scala.List$.loop$0(List.scala:232)
	at scala.List$.mapConserve(List.scala:249)
	at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:1013)
	at scala.tools.nsc.typechecker.Typers$Typer.typedTemplate(Typers.scala:717)
	at scala.tools.nsc.typechecker.Typers$Typer.typedClassDef(Typers.scala:645)
	at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:1478)
	at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:1815)
	at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:1842)
	at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$48.apply(Typers.scala:1024)
	at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$48.apply(Typers.scala:1013)
	at scala.List$.loop$0(List.scala:232)
	at scala.List$.mapConserve(List.scala:249)
	at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:1013)
	at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:1474)
	at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:1815)
	at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:1842)
	at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$1.apply(Analyzer.scala:38)
	at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:218)
	at scala.tools.nsc.Global$GlobalPhase$$anonfun$1.apply(Global.scala:207)
	at scala.tools.nsc.Global$GlobalPhase$$anonfun$1.apply(Global.scala:207)
	at scala.Iterator$class.foreach(Iterator.scala:316)
	at scala.collection.mutable.ListBuffer$$anon$0.foreach(ListBuffer.scala:216)
	at scala.tools.nsc.Global$GlobalPhase.run(Global.scala:207)
	at scala.tools.nsc.Global$Run.compileSources(Global.scala:469)
	at scala.tools.nsc.Global$Run.compile(Global.scala:533)
	at scala.tools.nsc.Main$.process(Main.scala:76)
	at scala.tools.nsc.Main$.main(Main.scala:98)
	at scala.tools.nsc.Main.main(Main.scala)
what expected no crash
[back to overview]
Changes of this bug report
Martin  edited on  2006-09-19 22:40:41.0