diff options
| -rw-r--r-- | src/compiler/scala/reflect/internal/Types.scala | 70 |
1 files changed, 31 insertions, 39 deletions
diff --git a/src/compiler/scala/reflect/internal/Types.scala b/src/compiler/scala/reflect/internal/Types.scala index 85a12193a9..88019f51f7 100644 --- a/src/compiler/scala/reflect/internal/Types.scala +++ b/src/compiler/scala/reflect/internal/Types.scala @@ -4114,29 +4114,41 @@ A type's typeSymbol should never be inspected directly. } } - /** A map to compute the most deeply nested owner that contains all the symbols + /** The most deeply nested owner that contains all the symbols * of thistype or prefixless typerefs/singletype occurrences in given type. */ - object commonOwnerMap extends TypeMap { - var result: Symbol = _ - def init() = { result = NoSymbol } - def apply(tp: Type): Type = { - assert(tp ne null) - tp.normalize match { - case ThisType(sym) => - register(sym) - case TypeRef(NoPrefix, sym, args) => - register(sym.owner); args foreach apply - case SingleType(NoPrefix, sym) => - register(sym.owner) - case _ => - mapOver(tp) - } - tp + private def commonOwner(t: Type): Symbol = commonOwner(t :: Nil) + + /** The most deeply nested owner that contains all the symbols + * of thistype or prefixless typerefs/singletype occurrences in given list + * of types. + */ + private def commonOwner(tps: List[Type]): Symbol = { + if (tps.isEmpty) NoSymbol + else { + commonOwnerMap.result = null + tps foreach (commonOwnerMap traverse _) + val result = if (commonOwnerMap.result ne null) commonOwnerMap.result else NoSymbol + debuglog(tps.mkString("commonOwner(", ", ", ") == " + result)) + result } + } + private object commonOwnerMap extends TypeTraverser { + var result: Symbol = _ + private def register(sym: Symbol) { - while (result != NoSymbol && sym != result && !(sym isNestedIn result)) - result = result.owner; + // First considered type is the trivial result. + if ((result eq null) || (sym eq NoSymbol)) + result = sym + else + while ((result ne NoSymbol) && (result ne sym) && !(sym isNestedIn result)) + result = result.owner + } + def traverse(tp: Type) = tp.normalize match { + case ThisType(sym) => register(sym) + case TypeRef(NoPrefix, sym, args) => register(sym.owner) ; args foreach traverse + case SingleType(NoPrefix, sym) => register(sym.owner) + case _ => mapOver(tp) } } @@ -5813,26 +5825,6 @@ A type's typeSymbol should never be inspected directly. if (ts exists (_.isNotNull)) res.notNull else res } - /** The most deeply nested owner that contains all the symbols - * of thistype or prefixless typerefs/singletype occurrences in given type. - */ - private def commonOwner(t: Type): Symbol = { - commonOwnerMap.init - commonOwnerMap.apply(t) - commonOwnerMap.result - } - - /** The most deeply nested owner that contains all the symbols - * of thistype or prefixless typerefs/singletype occurrences in given list - * of types. - */ - private def commonOwner(tps: List[Type]): Symbol = { - // debuglog("computing common owner of types " + tps)//DEBUG - commonOwnerMap.init - tps foreach { tp => commonOwnerMap.apply(tp); () } - commonOwnerMap.result - } - /** Compute lub (if `variance == 1`) or glb (if `variance == -1`) of given list * of types `tps`. All types in `tps` are typerefs or singletypes * with the same symbol. |