diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/typechecker/Duplicators.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Duplicators.scala | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala b/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala index 3536608efd..179bea0035 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala @@ -7,7 +7,6 @@ package scala.tools.nsc package typechecker import scala.tools.nsc.symtab.Flags - import scala.collection.{ mutable, immutable } /** Duplicate trees and re-type check them, taking care to replace @@ -18,6 +17,7 @@ import scala.collection.{ mutable, immutable } */ abstract class Duplicators extends Analyzer { import global._ + import definitions.{ AnyRefClass, AnyValClass } def retyped(context: Context, tree: Tree): Tree = { resetClassOwners @@ -308,17 +308,26 @@ abstract class Duplicators extends Analyzer { super.typed(atPos(tree.pos)(tree1)) */ case Match(scrut, cases) => - val scrut1 = typed(scrut, EXPRmode | BYVALmode, WildcardType) + val scrut1 = typed(scrut, EXPRmode | BYVALmode, WildcardType) val scrutTpe = scrut1.tpe.widen - val cases1 = if (scrutTpe.isFinalType) cases filter { - case CaseDef(Bind(_, pat @ Typed(_, tpt)), EmptyTree, body) => - // the typed pattern is not incompatible with the scrutinee type - scrutTpe.matchesPattern(fixType(tpt.tpe)) - case CaseDef(Typed(_, tpt), EmptyTree, body) => - // the typed pattern is not incompatible with the scrutinee type - scrutTpe.matchesPattern(fixType(tpt.tpe)) - case _ => true - } else cases + val cases1 = { + if (scrutTpe.isFinalType) cases filter { + case CaseDef(Bind(_, pat @ Typed(_, tpt)), EmptyTree, body) => + // the typed pattern is not incompatible with the scrutinee type + scrutTpe matchesPattern fixType(tpt.tpe) + case CaseDef(Typed(_, tpt), EmptyTree, body) => + // the typed pattern is not incompatible with the scrutinee type + scrutTpe matchesPattern fixType(tpt.tpe) + case _ => true + } + // Without this, AnyRef specializations crash on patterns like + // case _: Boolean => ... + // Not at all sure this is safe. + else if (scrutTpe <:< AnyRefClass.tpe) + cases filterNot (_.pat.tpe <:< AnyValClass.tpe) + else + cases + } super.typed(atPos(tree.pos)(Match(scrut, cases1)), mode, pt) |