*** empty log message ***

8 files changed, 45 insertions, 27 deletions

diff --git a/sources/scala/tools/nsc/Settings.scala b/sources/scala/tools/nsc/Settings.scala
index 0143525a67..8e66ee3dac 100644
--- a/sources/scala/tools/nsc/Settings.scala
+++ b/sources/scala/tools/nsc/Settings.scala
@@ -52,6 +52,7 @@ class Settings(error: String => unit) {
   val Xshowcls      = StringSetting ("-Xshowcls", "class", "Show class info", "");
   val Xshowobj      = StringSetting ("-Xshowobj", "object", "Show object info", "");
   val Xshowicode    = BooleanSetting("-Xshowicode", "Print the generated ICode");
+  val Xgadt         = BooleanSetting("-Xgadt", "enable gadt for classes");
 
   /** A list of all settings */
   def allSettings: List[Setting] = allsettings.reverse;
diff --git a/sources/scala/tools/nsc/ast/TreeGen.scala b/sources/scala/tools/nsc/ast/TreeGen.scala
index 8d2f30bd4d..425cf9eac8 100755
--- a/sources/scala/tools/nsc/ast/TreeGen.scala
+++ b/sources/scala/tools/nsc/ast/TreeGen.scala
@@ -24,12 +24,16 @@ abstract class TreeGen {
     case ThisType(clazz) =>
       if (clazz.isRoot || clazz.isEmptyPackageClass) EmptyTree else This(clazz)
     case SingleType(pre, sym) =>
-      val qual = mkStableRef(pre, sym);
-      qual.tpe match {
-	case MethodType(List(), restpe) =>
-	  Apply(qual, List()) setType restpe
-        case _ =>
-          qual
+      if (sym.isThisSkolem) {
+        mkQualifier(ThisType(sym.deSkolemize))
+      } else {
+        val qual = mkStableRef(pre, sym);
+        qual.tpe match {
+          case MethodType(List(), restpe) =>
+            Apply(qual, List()) setType restpe
+          case _ =>
+            qual
+        }
       }
     case TypeRef(pre, sym, args) =>
       assert(phase.erasedTypes);
diff --git a/sources/scala/tools/nsc/symtab/StdNames.scala b/sources/scala/tools/nsc/symtab/StdNames.scala
index a984e9e491..c20843843a 100755
--- a/sources/scala/tools/nsc/symtab/StdNames.scala
+++ b/sources/scala/tools/nsc/symtab/StdNames.scala
@@ -76,6 +76,7 @@ import scala.tools.nsc.util.NameTransformer;
     val IMPL_CLASS_SUFFIX = newTermName("$class");
     val MODULE_SUFFIX = newTermName("$module");
     val LOCALDUMMY_PREFIX = newTermName(LOCALDUMMY_PREFIX_STRING);
+    val THIS_SUFFIX = newTermName(".this");
 
     def isLocalName(name: Name) = name.endsWith(LOCAL_SUFFIX);
     def isSetterName(name: Name) = name.endsWith(SETTER_SUFFIX);
diff --git a/sources/scala/tools/nsc/symtab/Symbols.scala b/sources/scala/tools/nsc/symtab/Symbols.scala
index cc8a907a02..1a0d4017c4 100755
--- a/sources/scala/tools/nsc/symtab/Symbols.scala
+++ b/sources/scala/tools/nsc/symtab/Symbols.scala
@@ -70,6 +70,9 @@ import Flags._;
     final def newThisSym(pos: int) = {
       newValue(pos, nme.this_).setFlag(SYNTHETIC);
     }
+    final def newThisSkolem: Symbol =
+      new ThisSkolem(owner, pos, name, this)
+        .setFlag(SYNTHETIC | FINAL);
     final def newImport(pos: int) =
       newValue(pos, nme.IMPORT).setFlag(SYNTHETIC);
     final def newOverloaded(pre: Type, alternatives: List[Symbol]): Symbol =
@@ -85,7 +88,7 @@ import Flags._;
       new TypeSymbol(this, pos, name).setFlag(DEFERRED);
     final def newTypeParameter(pos: int, name: Name) =
       newAbstractType(pos, name).setFlag(PARAM);
-    final def newSkolem: Symbol =
+    final def newTypeSkolem: Symbol =
       new TypeSkolem(owner, pos, name, this)
         .setFlag(flags);
     final def newClass(pos: int, name: Name) =
@@ -129,6 +132,7 @@ import Flags._;
     final def isStaticModule = isModule && isStatic && !isMethod;
     final def isPackage = isModule && hasFlag(PACKAGE);
     final def isThisSym = isTerm && name == nme.this_;
+    final def isThisSkolem = isTerm && deSkolemize != this;
     final def isError = hasFlag(IS_ERROR);
     final def isTrait = isClass & hasFlag(TRAIT);
     final def isAliasType = isType && !isClass && !hasFlag(DEFERRED);
@@ -811,6 +815,15 @@ import Flags._;
     }
   }
 
+  /** A class for type parameters viewed from inside their scopes */
+  class ThisSkolem(initOwner: Symbol, initPos: int, initName: Name, clazz: Symbol) extends TermSymbol(initOwner, initPos, initName) {
+    override def deSkolemize = clazz;
+    override def cloneSymbolImpl(owner: Symbol): Symbol = {
+      throw new Error("should not clone a this skolem");
+    }
+    override def nameString: String = clazz.name.toString() + ".this";
+  }
+
   /** A class of type symbols. Alias and abstract types are direct instances
    *  of this class. Classes are instances of a subclass.
    */
@@ -983,8 +996,8 @@ import Flags._;
     syms1
   }
 
-  def newSkolems(tparams: List[Symbol]): List[Symbol] = {
-    val tskolems = tparams map (.newSkolem);
+  def newTypeSkolems(tparams: List[Symbol]): List[Symbol] = {
+    val tskolems = tparams map (.newTypeSkolem);
     val ltp = new LazyType {
       override def complete(sym: Symbol): unit =
         sym setInfo sym.deSkolemize.info.substSym(tparams, tskolems);
diff --git a/sources/scala/tools/nsc/symtab/Types.scala b/sources/scala/tools/nsc/symtab/Types.scala
index 3faa808ee3..30f20cd8ff 100755
--- a/sources/scala/tools/nsc/symtab/Types.scala
+++ b/sources/scala/tools/nsc/symtab/Types.scala
@@ -1311,6 +1311,9 @@ import Flags._;
       }
     }
     def apply(tp: Type): Type = tp match {
+      case ThisType(sym) if (sym.isModuleClass) =>
+        val sym1 = adaptToNewRun(sym.owner.thisType, sym);
+        if (sym1 == sym) tp else ThisType(sym1)
       case SingleType(pre, sym) =>
 	if (sym.isPackage) tp
 	else {
diff --git a/sources/scala/tools/nsc/typechecker/Contexts.scala b/sources/scala/tools/nsc/typechecker/Contexts.scala
index da911ceb78..d6608f3521 100755
--- a/sources/scala/tools/nsc/typechecker/Contexts.scala
+++ b/sources/scala/tools/nsc/typechecker/Contexts.scala
@@ -63,7 +63,7 @@ import scala.tools.nsc.util.Position;
     var depth: int = 0;
     var imports: List[ImportInfo] = List();
 
-    var thisSkolemType: Type = NoPrefix;
+    var prefix: Type = NoPrefix;
     var reportAmbiguousErrors = false;
     var reportGeneralErrors = false;
     var checking = false;
@@ -85,10 +85,10 @@ import scala.tools.nsc.util.Position;
       tree match {
         case Template(_, _) | PackageDef(_, _) =>
 	  c.enclClass = c;
-	  c.thisSkolemType = skolemizedThisType(c.owner)
+	  c.prefix = skolemizedThisType(this.prefix, c.owner)
 	case _ =>
 	  c.enclClass = this.enclClass;
-	  c.thisSkolemType = this.thisSkolemType
+          c.prefix = if (c.owner != this.owner && c.owner.isTerm) NoPrefix else this.prefix
       }
       c.variance = this.variance;
       c.depth = if (scope == this.scope) this.depth else this.depth + 1;
@@ -129,18 +129,14 @@ import scala.tools.nsc.util.Position;
       c
     }
 
-    def skolemizedThisType(clazz: Symbol): Type = {
-      clazz.thisType
-      /* not yet (GADT)
+    def skolemizedThisType(pre: Type, clazz: Symbol): Type = if (settings.Xgadt.value) {
       val tparams = clazz.unsafeTypeParams;
-      if (tparams.isEmpty) clazz.thisType
-      else {
-        val self = clazz.newThisSym(clazz.pos)
-        setInfo clazz.typeOfThis.substSym(tparams, newSkolems(tparams));
-        singleType(clazz.thisType, self)
-      }
-      */
-    }
+      if (pre.isInstanceOf[SingleType] || !tparams.isEmpty) {
+        val self = clazz.newThisSkolem
+          setInfo clazz.typeOfThis.substSym(tparams, newTypeSkolems(tparams));
+        singleType(pre, self)
+      } else clazz.thisType
+    } else clazz.thisType;
 
     def error(pos: int, msg: String): unit =
       if (reportGeneralErrors)
diff --git a/sources/scala/tools/nsc/typechecker/Namers.scala b/sources/scala/tools/nsc/typechecker/Namers.scala
index 3f7dd81be5..a836e0b0f6 100755
--- a/sources/scala/tools/nsc/typechecker/Namers.scala
+++ b/sources/scala/tools/nsc/typechecker/Namers.scala
@@ -126,7 +126,7 @@ trait Namers: Analyzer {
       def finish = finishWith(List());
 
       def skolemize(tparams: List[AbsTypeDef]): unit = {
-	val tskolems = newSkolems(tparams map (.symbol));
+	val tskolems = newTypeSkolems(tparams map (.symbol));
         for (val Pair(tparam, tskolem) <- tparams zip tskolems) tparam.symbol = tskolem
       }
 
diff --git a/sources/scala/tools/nsc/typechecker/Typers.scala b/sources/scala/tools/nsc/typechecker/Typers.scala
index 5ca4feb0b5..267a9ca838 100755
--- a/sources/scala/tools/nsc/typechecker/Typers.scala
+++ b/sources/scala/tools/nsc/typechecker/Typers.scala
@@ -959,7 +959,7 @@ import collection.mutable.HashMap;
 
 	  var cx = context;
 	  while (defSym == NoSymbol && cx != NoContext) {
-	    pre = cx.enclClass.thisSkolemType;
+	    pre = cx.enclClass.prefix;
 	    defEntry = cx.scope.lookupEntry(name);
 	    if (defEntry != null) {
 	      defSym = defEntry.sym;
@@ -1240,7 +1240,7 @@ import collection.mutable.HashMap;
               Pair(tree.symbol, tree.symbol.thisType)
             } else {
               val clazzContext = qualifyingClassContext(qual);
-              Pair(clazzContext.owner, clazzContext.thisSkolemType)
+              Pair(clazzContext.owner, clazzContext.prefix)
             }
           if (clazz == NoSymbol) setError(tree)
           else {
@@ -1265,7 +1265,7 @@ import collection.mutable.HashMap;
               Pair(tree.symbol, tree.symbol.thisType)
             } else {
               val clazzContext = qualifyingClassContext(qual);
-              Pair(clazzContext.owner, clazzContext.thisSkolemType)
+              Pair(clazzContext.owner, clazzContext.prefix)
             }
           if (clazz == NoSymbol) setError(tree)
           else {