| [#1251] | project: compiler | priority: high | category: bug | |
|---|---|---|---|---|
| submitter | assigned to | status | date submitted | |
| Martin | Burak | fixed | 2007-07-28 11:00:58.0 | |
| subject | [contrib #722] Compiler crash on type inference in match block | |||
| code |
object Z {
case class X
"" match {
case "" => new Array[X](1)
case _ => Nil
}
} |
|||
| what happened | Compiler crashes:
java.lang.NullPointerException
at scala.$colon$colon.equals(List.scala:1204)
at scala.$colon$colon.equals(List.scala:1204)
at scala.$colon$colon.equals(List.scala:1204)
at scala.$colon$colon.equals(List.scala:1204)
at scala.tools.nsc.ast.Trees$LazyTreeCopier.Template(Trees.scala:1025)
at scala.tools.nsc.transform.Erasure$ErasureTransformer$$anon$2.transform(Erasure.scala:848)
at scala.tools.nsc.ast.Trees$Transformer.transformTemplate(Trees.scala:1311)
at scala.tools.nsc.ast.Trees$Transformer$$anonfun$21.apply(Trees.scala:1209)
at scala.tools.nsc.ast.Trees$Transformer$$anonfun$21.apply(Trees.scala:1209)
at scala.tools.nsc.ast.Trees$Transformer.atOwner(Trees.scala:1333)
at scala.tools.nsc.ast.Trees$Transformer.transform(Trees.scala:1208)
at scala.tools.nsc.transform.Erasure$ErasureTransformer$$anon$2.transform(Erasure.scala:864)
at scala.tools.nsc.ast.Trees$Transformer$$anonfun$33.apply(Trees.scala:1327)
at scala.tools.nsc.ast.Trees$Transformer$$anonfun$33.apply(Trees.scala:1325)
at scala.List$.loop$0(List.scala:244)
at scala.List$.mapConserve(List.scala:261)
at scala.tools.nsc.ast.Trees$Transformer.transformStats(Trees.scala:1325)
at scala.tools.nsc.ast.Trees$Transformer$$anonfun$20.apply(Trees.scala:1205)
at scala.tools.nsc.ast.Trees$Transformer$$anonfun$20.apply(Trees.scala:1205)
at scala.tools.nsc.ast.Trees$Transformer.atOwner(Trees.scala:1333)
at scala.tools.nsc.ast.Trees$Transformer.transform(Trees.scala:1204)
at scala.tools.nsc.transform.Erasure$ErasureTransformer$$anon$2.transform(Erasure.scala:864)
at scala.tools.nsc.transform.Erasure$ErasureTransformer.transform(Erasure.scala:873)
at scala.tools.nsc.ast.Trees$Transformer.transformUnit(Trees.scala:1328)
at scala.tools.nsc.transform.Transform$Phase.apply(Transform.scala:30)
at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:258)
at scala.tools.nsc.Global$GlobalPhase$$anonfun$2.apply(Global.scala:247)
at scala.tools.nsc.Global$GlobalPhase$$anonfun$2.apply(Global.scala:247)
at scala.Iterator$class.foreach(Iterator.scala:375)
at scala.collection.mutable.ListBuffer$$anon$0.foreach(ListBuffer.scala:255)
at scala.tools.nsc.Global$GlobalPhase.run(Global.scala:247)
at scala.tools.nsc.Global$Run.compileSources(Global.scala:542)
at scala.tools.nsc.Global$Run.compile(Global.scala:623)
at scala.tools.nsc.StandardCompileServer.session(CompileServer.scala:143)
at scala.tools.util.SocketServer$$anonfun$0.apply(SocketServer.scala:69)
at scala.tools.util.SocketServer$$anonfun$0.apply(SocketServer.scala:69)
at scala.util.DynamicVariable.withValue(DynamicVariable.scala:73)
at scala.Console$.withOut(Console.scala:84)
at scala.Console$.withOut(Console.scala:102)
at scala.tools.util.SocketServer.run(SocketServer.scala:68)
at scala.tools.nsc.StandardCompileServer.main(CompileServer.scala:185)
at scala.tools.nsc.CompileServer.main(CompileServer.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at scala.tools.nsc.ObjectRunner$$anonfun$0.apply(ObjectRunner.scala:75)
at scala.tools.nsc.ObjectRunner$.withContextClassLoader(ObjectRunner.scala:49)
at scala.tools.nsc.ObjectRunner$.run(ObjectRunner.scala:74)
at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:154)
at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)
error: fatal error (server aborted): null
one error found
[died while typechecking the translated pattern match:]
if ("".==(""))
body32345120(){
new Array[Z.this.X](1)
}
else
body9092916(){
scala.Nil
}
|
|||
| what expected | Silent compilation | |||
| [back to overview] | ||||
| Martin edited on 2007-07-28 11:03:23.0 |
| Martin edited on 2007-07-28 11:31:26.0 |
I fixed the first problem but now we get another error:
scala.tools.nsc.symtab.Types$TypeError: type mismatch;
found : Seq[Z.this.X]{def projection(): Seq.Projection[Z.this.X]{def append[B >: Z.this.X](() => Iterable[B(in method append)]): Seq.Projection[B(in method append)]}}
required: Seq[Z.this.X]{def projection(): Seq.Projection[Z.this.X]{def append[B >: Z.this.X](() => Iterable[(some other)(some other)B(in method append)]): Seq.Projection[(some other)(some other)B(in method append)]}}
It seems the types are needlessly complex. Maybe we can solve this by adding result type annotations to the generated bodyXXXXXXX methods?
|
| Burak edited on 2007-08-14 18:10:07.0 |
| I do assign result type of the match now. this used to crash the compiler elsewhere but I worked around it by special casing: when the body has tpe Nothing, I use that type (it gives problems when Nothing is used in place of Unit, the typer does not digest just setting the type by fiat for this combination... this problem will probably surface elsewhere later) |