*** empty log message ***

7 files changed, 132 insertions, 26 deletions

diff --git a/sources/scalac/ast/TreeGen.java b/sources/scalac/ast/TreeGen.java
index 1bbb32aebf..4abd940f9c 100644
--- a/sources/scalac/ast/TreeGen.java
+++ b/sources/scalac/ast/TreeGen.java
@@ -1094,7 +1094,7 @@ public class TreeGen implements Kinds, Modifiers, TypeTags {
 	AbsTypeDef tree = make.AbsTypeDef(
 	    sym.pos,
             sym,
-            TypeTerm(sym.pos, sym.nextInfo()),
+            TypeTerm(sym.pos, sym.isViewBounded() ? sym.vuBound() : sym.nextInfo()),
             TypeTerm(sym.pos, sym.loBound()));
         tree.setType(Type.NoType);
         return tree;
diff --git a/sources/scalac/symtab/ClosureHistory.java b/sources/scalac/symtab/ClosureHistory.java
index 8825fb3e20..c17ad46f90 100644
--- a/sources/scalac/symtab/ClosureHistory.java
+++ b/sources/scalac/symtab/ClosureHistory.java
@@ -14,6 +14,7 @@ import java.util.TreeMap;
 import scalac.Global;
 import scalac.framework.History;
 import scalac.util.Debug;
+import scalac.util.ArrayApply;
 
 /** This class implements a closure history. */
 public class ClosureHistory extends History {
@@ -43,6 +44,7 @@ public class ClosureHistory extends History {
         closure[0] = clasz.type();
         for (int i = 1; i < closure.length; i++)
             closure[i] = (Type)types.next();
+	//System.out.println("closure(" + owner + ") = " + ArrayApply.toString(closure));//DEBUG
         return closure;
     }
 
diff --git a/sources/scalac/symtab/Symbol.java b/sources/scalac/symtab/Symbol.java
index c65bdcdc6c..ccd9f2632a 100644
--- a/sources/scalac/symtab/Symbol.java
+++ b/sources/scalac/symtab/Symbol.java
@@ -504,6 +504,12 @@ public abstract class Symbol implements Modifiers, Kinds {
         throw new ApplicationError("setLoBound inapplicable for " + this);
     }
 
+    /** Set the view bound of this type variable
+     */
+    public Symbol setVuBound(Type lobound) {
+        throw new ApplicationError("setVuBound inapplicable for " + this);
+    }
+
     /** Add an auxiliary constructor to class.
      */
     public void addConstructor(Symbol constr) {
@@ -575,6 +581,13 @@ public abstract class Symbol implements Modifiers, Kinds {
         return kind == VAL && (flags & MUTABLE) != 0;
     }
 
+    /** Does this symbol denote a view bounded type variable? */
+    public final boolean isViewBounded() {
+	Global global = Global.instance;
+        return kind == TYPE && (flags & VIEWBOUND) != 0 &&
+	    global.currentPhase.id <= global.PHASE.REFCHECK.id();
+    }
+
     /**
      * Does this symbol denote a final method? A final method is one
      * that can't be overridden in a subclass. This method assumes
@@ -1278,6 +1291,12 @@ public abstract class Symbol implements Modifiers, Kinds {
         return Global.instance.definitions.ALL_TYPE();
     }
 
+    /** The view bound of this type variable
+     */
+    public Type vuBound() {
+        return Global.instance.definitions.ANY_TYPE();
+    }
+
     /** Get this.type corresponding to this symbol
      */
     public Type thisType() {
@@ -1757,6 +1776,7 @@ final class AliasTypeSymbol extends TypeSymbol {
 final class AbsTypeSymbol extends TypeSymbol {
 
     private Type lobound = null;
+    private Type vubound = null;
 
     /** Initializes this instance. */
     AbsTypeSymbol(int pos, Name name, Symbol owner, int flags, int attrs) {
@@ -1769,14 +1789,25 @@ final class AbsTypeSymbol extends TypeSymbol {
         return lobound == null ? Global.instance.definitions.ALL_TYPE() : lobound;
     }
 
+    public Type vuBound() {
+        initialize();
+        return vubound == null ? Global.instance.definitions.ANY_TYPE() : vubound;
+    }
+
     public Symbol setLoBound(Type lobound) {
         this.lobound = lobound;
         return this;
     }
 
+    public Symbol setVuBound(Type vubound) {
+	this.vubound = vubound;
+        return this;
+    }
+
     protected TypeSymbol cloneTypeSymbolImpl(Symbol owner, int attrs) {
         TypeSymbol clone = new AbsTypeSymbol(pos, name, owner, flags, attrs);
         clone.setLoBound(loBound());
+        clone.setVuBound(vuBound());
         return clone;
     }
 
diff --git a/sources/scalac/symtab/Type.java b/sources/scalac/symtab/Type.java
index 9adcade4a2..4bff125e53 100644
--- a/sources/scalac/symtab/Type.java
+++ b/sources/scalac/symtab/Type.java
@@ -1035,8 +1035,10 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
                     }
                     for (int i = 0; i < syms2.length; i++) {
                         syms2[i].setInfo(syms1[i].info().subst(syms1, syms2));
-                        if (syms2[i].kind == TYPE)
+                        if (syms2[i].kind == TYPE) {
                             syms2[i].setLoBound(syms1[i].loBound().subst(syms1, syms2));
+                            syms2[i].setVuBound(syms1[i].vuBound().subst(syms1, syms2));
+			}
                     }
                     for (int i = 0; i < syms2.length; i++) {
                         members2.enter(syms2[i]);
@@ -1086,6 +1088,12 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
                     if (!dontClone) sym = sym.cloneSymbol();
                     sym.setLoBound(lb1);
                 }
+                Type vb = sym.vuBound();
+                Type vb1 = apply(vb);
+                if (vb != vb1) {
+                    if (!dontClone) sym = sym.cloneSymbol();
+                    sym.setVuBound(vb1);
+                }
             }
             return sym;
         }
@@ -1319,6 +1327,12 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
         return sym.loBound().asSeenFrom(this, sym.owner());
     }
 
+    /** The view bound of `sym', seen as a member of this type.
+     */
+    public Type memberVuBound(Symbol sym) {
+        return sym.vuBound().asSeenFrom(this, sym.owner());
+    }
+
 // Substitutions ---------------------------------------------------------------
 
     /** A common map superclass for symbol/symbol and type/symbol substitutions.
@@ -1920,7 +1934,8 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
                 if (ps.length != ps1.length) return false;
                 for (int i = 0; i < ps.length; i++)
                     if (!ps1[i].info().subst(ps1, ps).isSameAs(ps[i].info()) ||
-                        !ps[i].loBound().isSameAs(ps1[i].loBound().subst(ps1, ps)))
+                        !ps[i].loBound().isSameAs(ps1[i].loBound().subst(ps1, ps)) ||
+                        !ps[i].vuBound().isSameAs(ps1[i].vuBound().subst(ps1, ps)))
                         return false;
                 return res.isSubType(res1.subst(ps1, ps));
             }
@@ -1979,9 +1994,9 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
                 return true;
             }
 
-        case TypeRef(_, Symbol sym, Type[] args):
+        case TypeRef(_, Symbol sym, _):
             switch (that) {
-            case TypeRef(Type pre1, Symbol sym1, _):
+            case TypeRef(_, Symbol sym1, _):
                 if (sym1.kind == TYPE && this.isSubType(that.loBound()))
                     return true;
             }
@@ -2092,7 +2107,9 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
              self.memberInfo(sym).subst(tparams, targs)
              .isSubType(sym1.info().substThis(sym1.owner(), self)) &&
              sym1.loBound().substThis(sym1.owner(), self)
-             .isSubType(self.memberLoBound(sym).subst(tparams, targs))
+             .isSubType(self.memberLoBound(sym).subst(tparams, targs)) &&
+             self.memberVuBound(sym).subst(tparams, targs)
+             .isSubType(sym1.vuBound().substThis(sym1.owner(), self))
              ||
              (sym.kind == TYPE && sym1.kind == ALIAS &&
               sym1.info().unalias().isSameAs(sym.type())));
@@ -2203,7 +2220,8 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
                 if (ps.length != ps1.length) return false;
                 for (int i = 0; i < ps.length; i++)
                     if (!ps1[i].info().subst(ps1, ps).isSameAs(ps[i].info()) ||
-                        !ps1[i].loBound().subst(ps1, ps).isSameAs(ps[i].loBound()))
+                        !ps1[i].loBound().subst(ps1, ps).isSameAs(ps[i].loBound()) ||
+                        !ps1[i].vuBound().subst(ps1, ps).isSameAs(ps[i].vuBound()))
                         return false;
                 return res.isSameAs(res1.subst(ps1, ps));
             }
@@ -2293,6 +2311,9 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
                         sym2.owner(), sym1.owner().thisType())) ||
                 !sym1.loBound().isSameAs(
                     sym2.loBound().substThis(
+                        sym2.owner(), sym1.owner().thisType())) ||
+                !sym1.vuBound().isSameAs(
+                    sym2.vuBound().substThis(
                         sym2.owner(), sym1.owner().thisType())))
                 return false;
         }
@@ -2656,6 +2677,7 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
     private static Type polyLub(Type[] tps, Symbol[] tparams0) {
         Type[][] hiboundss = new Type[tparams0.length][tps.length];
         Type[][] loboundss = new Type[tparams0.length][tps.length];
+        Type[][] vuboundss = new Type[tparams0.length][tps.length];
         Type[] restps   = new Type[tps.length];
         for (int i = 0; i < tps.length; i++) {
             switch (tps[i]) {
@@ -2666,6 +2688,8 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
                             .subst(tparams, tparams0);
                         loboundss[j][i] = tparams[j].loBound()
                             .subst(tparams, tparams0);
+                        vuboundss[j][i] = tparams[j].vuBound()
+                            .subst(tparams, tparams0);
                     }
                     restps[i] = restp.subst(tparams, tparams0);
                 } else {
@@ -2678,15 +2702,18 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
         }
         Type[] hibounds = new Type[tparams0.length];
         Type[] lobounds = new Type[tparams0.length];
+        Type[] vubounds = new Type[tparams0.length];
         for (int j = 0; j < tparams0.length; j++) {
             hibounds[j] = glb(hiboundss[j]);
             lobounds[j] = lub(loboundss[j]);
+            vubounds[j] = glb(vuboundss[j]);
         }
         Symbol[] tparams = new Symbol[tparams0.length];
         for (int j = 0; j < tparams.length; j++) {
             tparams[j] = tparams0[j].cloneSymbol(Symbol.NONE)
                 .setInfo(hibounds[j].subst(tparams0, tparams))
-                .setLoBound(lobounds[j].subst(tparams0, tparams));
+                .setLoBound(lobounds[j].subst(tparams0, tparams))
+                .setVuBound(vubounds[j].subst(tparams0, tparams));
         }
         return Type.PolyType(tparams, lub(restps).subst(tparams0, tparams));
     }
@@ -2899,11 +2926,15 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
     private static boolean addMember(Scope s, Symbol sym, Type glbThisType) {
         Type syminfo = sym.info().substThis(sym.owner(), glbThisType);
         Type symlb = sym.loBound().substThis(sym.owner(), glbThisType);
+        Type symvb = sym.vuBound().substThis(sym.owner(), glbThisType);
         Scope.Entry e = s.lookupEntry(sym.name);
         if (e == Scope.Entry.NONE) {
             Symbol sym1 = sym.cloneSymbol(glbThisType.symbol());
             sym1.setInfo(syminfo);
-            if (sym1.kind == TYPE) sym1.setLoBound(symlb);
+            if (sym1.kind == TYPE) {
+		sym1.setLoBound(symlb);
+		sym1.setVuBound(symvb);
+	    }
             s.enter(sym1);
         } else {
             Type einfo = e.sym.info();
@@ -2926,6 +2957,14 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
                 } else {
                     e.sym.setLoBound(lub(new Type[]{elb, symlb}));
                 }
+                Type evb = e.sym.vuBound();
+                if (evb.isSameAs(symvb)) {
+                } else if (evb.isSubType(symvb)) {
+                } else if (symvb.isSubType(evb)) {
+                    e.sym.setVuBound(symvb);
+                } else {
+                    e.sym.setVuBound(glb(new Type[]{evb, symvb}));
+                }
             }
         }
         return true;
@@ -2934,6 +2973,7 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
     private static Type polyGlb(Type[] tps, Symbol[] tparams0) {
         Type[][] hiboundss = new Type[tparams0.length][tps.length];
         Type[][] loboundss = new Type[tparams0.length][tps.length];
+        Type[][] vuboundss = new Type[tparams0.length][tps.length];
         Type[] restps   = new Type[tps.length];
         for (int i = 0; i < tps.length; i++) {
             switch (tps[i]) {
@@ -2944,6 +2984,8 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
                             .subst(tparams, tparams0);
                         loboundss[j][i] = tparams[j].loBound()
                             .subst(tparams, tparams0);
+                        vuboundss[j][i] = tparams[j].vuBound()
+                            .subst(tparams, tparams0);
                     }
                     restps[i] = restp.subst(tparams, tparams0);
                 } else {
@@ -2956,15 +2998,18 @@ public class Type implements Modifiers, Kinds, TypeTags, EntryTags {
         }
         Type[] hibounds = new Type[tparams0.length];
         Type[] lobounds = new Type[tparams0.length];
+        Type[] vubounds = new Type[tparams0.length];
         for (int j = 0; j < tparams0.length; j++) {
             hibounds[j] = lub(hiboundss[j]);
             lobounds[j] = glb(loboundss[j]);
+            vubounds[j] = lub(vuboundss[j]);
         }
         Symbol[] tparams = new Symbol[tparams0.length];
         for (int j = 0; j < tparams.length; j++) {
             tparams[j] = tparams0[j].cloneSymbol(Symbol.NONE)
                 .setInfo(hibounds[j].subst(tparams0, tparams))
-                .setLoBound(lobounds[j].subst(tparams0, tparams));
+                .setLoBound(lobounds[j].subst(tparams0, tparams))
+                .setVuBound(vubounds[j].subst(tparams0, tparams));
         }
         return Type.PolyType(tparams, glb(restps).subst(tparams0, tparams));
     }
diff --git a/sources/scalac/symtab/classfile/Pickle.java b/sources/scalac/symtab/classfile/Pickle.java
index fcf3143da7..2c46855821 100644
--- a/sources/scalac/symtab/classfile/Pickle.java
+++ b/sources/scalac/symtab/classfile/Pickle.java
@@ -118,15 +118,18 @@ public class Pickle implements Kinds, Modifiers, EntryTags {
 	    if (isLocal(sym)) {
 		putEntry(sym.name);
 		putSymbol(sym.isConstructor() ? sym.constructorClass() : sym.owner());
-		putType(sym.info());
 		switch (sym.kind) {
 		case TYPE:
+		    if (sym.isViewBounded()) putType(sym.vuBound());
+		    else putType(sym.info());
 		    putType(sym.loBound());
 		    break;
 		case ALIAS:
+		    putType(sym.info());
 		    putSymbol(sym.allConstructors());
 		    break;
 		case CLASS:
+		    putType(sym.info());
 		    putType(sym.typeOfThis());
 		    putSymbol(sym.allConstructors());
 		    for (Scope.SymbolIterator it = sym.members().iterator();
@@ -134,6 +137,7 @@ public class Pickle implements Kinds, Modifiers, EntryTags {
 			putSymbol(it.next());
 		    break;
 		case VAL:
+		    putType(sym.info());
 		    if (sym.isConstructor() &&
 			sym == sym.constructorClass().allConstructors())
 			putSymbol(sym.constructorClass());
@@ -336,25 +340,31 @@ public class Pickle implements Kinds, Modifiers, EntryTags {
 	    writeRef(sym.name);
 	    writeRef(sym.isConstructor() ? sym.constructorClass() : sym.owner());
 	    writeNat(sym.flags);
-	    writeRef(sym.info());
 	    switch (sym.kind) {
 	    case TYPE:
+		if (sym.isViewBounded()) writeRef(sym.vuBound());
+		else writeRef(sym.info());
 		writeRef(sym.loBound());
 		break;
 	    case ALIAS:
+		writeRef(sym.info());
 		writeRef(sym.allConstructors());
 		break;
 	    case CLASS:
+		writeRef(sym.info());
 		writeRef(sym.typeOfThis());
 		writeRef(sym.allConstructors());
 		break;
 	    case VAL:
+		writeRef(sym.info());
 		if (sym.isConstructor() &&
 		    sym == sym.constructorClass().allConstructors())
 		    writeRef(sym.constructorClass());
 		else if (sym.isModule())
 		    writeRef(sym.moduleClass());
 		break;
+	    default:
+		throw new ApplicationError();
 	    }
 	} else if (sym.kind == NONE) {
 	    writeByte(NONEsym);
diff --git a/sources/scalac/symtab/classfile/UnPickle.java b/sources/scalac/symtab/classfile/UnPickle.java
index 74a7027424..ba27cbbf60 100644
--- a/sources/scalac/symtab/classfile/UnPickle.java
+++ b/sources/scalac/symtab/classfile/UnPickle.java
@@ -244,7 +244,12 @@ public class UnPickle implements Kinds, Modifiers, EntryTags, TypeTags {
 		    case TYPEsym:
 			entries[n] = sym = owner.newAbstractType(
 			    Position.NOPOS, flags, name);
-			sym.setInfo(getType(inforef, sym));
+			if ((flags & VIEWBOUND) != 0) {
+			    sym.setInfo(global.definitions.ANY_TYPE());
+			    sym.setVuBound(getType(inforef, sym));
+			} else {
+			    sym.setInfo(getType(inforef, sym));
+			}
 			sym.setLoBound(readTypeRef(sym));
 			break;
 
diff --git a/sources/scalac/typechecker/RefCheck.java b/sources/scalac/typechecker/RefCheck.java
index c7e2572d72..2bb96cbe69 100644
--- a/sources/scalac/typechecker/RefCheck.java
+++ b/sources/scalac/typechecker/RefCheck.java
@@ -58,6 +58,8 @@ public class RefCheck extends Transformer implements Modifiers, Kinds {
 
 // Override checking ------------------------------------------------------------
 
+    static final int HIBOUND = 0, LOBOUND = 1, VUBOUND = 2;
+
     static boolean isIncomplete(Symbol sym) {
 	return sym.isDeferred() ||
 	    sym.isAbstractOverride() &&
@@ -255,15 +257,17 @@ public class RefCheck extends Transformer implements Modifiers, Kinds {
 		if (other.typeParams().length != 0)
 		    overrideError(pos, member, other, "may not override parameterized type");
 		if (!self.memberType(member).isSameAs(self.memberType(other)))
-		    overrideTypeError(pos, member, other, self, false);
+		    overrideTypeError(pos, member, other, self, HIBOUND);
 		break;
 	    case TYPE:
 		if (member.typeParams().length != 0)
 		    overrideError(pos, member, other, "may not be parameterized");
 		if (!self.memberInfo(member).isSubType(self.memberInfo(other)))
-		    overrideTypeError(pos, member, other, self, false);
+		    overrideTypeError(pos, member, other, self, HIBOUND);
 		if (!self.memberLoBound(other).isSubType(self.memberLoBound(member)))
-		    overrideTypeError(pos, member, other, self, true);
+		    overrideTypeError(pos, member, other, self, LOBOUND);
+		if (!self.memberVuBound(member).isSubType(self.memberVuBound(other)))
+		    overrideTypeError(pos, member, other, self, VUBOUND);
 		break;
 	    default:
 		if (other.isConstructor())
@@ -271,7 +275,7 @@ public class RefCheck extends Transformer implements Modifiers, Kinds {
 				  "cannot override a class constructor");
 		if (!normalizedInfo(self, member).isSubType(
 			normalizedInfo(self, other)))
-		    overrideTypeError(pos, member, other, self, false);
+		    overrideTypeError(pos, member, other, self, HIBOUND);
 	    }
 	}
     }
@@ -284,17 +288,25 @@ public class RefCheck extends Transformer implements Modifiers, Kinds {
     }
 
     void overrideTypeError(int pos, Symbol member, Symbol other, Type site,
-			   boolean lobound) {
+			   int boundkind) {
 	if (!other.type().isError() && !member.type().isError()) {
-	    Type memberInfo = lobound ? site.memberLoBound(member)
-		: normalizedInfo(site, member);
-	    Type otherInfo = lobound ? site.memberLoBound(other)
-		: normalizedInfo(site, other);
+	    Type memberInfo;
+	    Type otherInfo;
+	    if (boundkind == LOBOUND) {
+		memberInfo = site.memberLoBound(member);
+		otherInfo = site.memberLoBound(other);
+	    } else if (boundkind == VUBOUND) {
+		memberInfo = site.memberVuBound(member);
+		otherInfo = site.memberVuBound(other);
+	    } else {
+		memberInfo = normalizedInfo(site, member);
+		otherInfo = normalizedInfo(site, other);
+	    }
 	    unit.error(pos,
 		member + member.locationString() +
-		infoString(member, memberInfo, lobound) +
+		infoString(member, memberInfo, boundkind) +
 		"\n cannot override " + other + other.locationString() +
-		infoString(other, otherInfo, lobound));
+		infoString(other, otherInfo, boundkind));
 	    Type.explainTypes(memberInfo, otherInfo);
 	}
     }
@@ -303,10 +315,10 @@ public class RefCheck extends Transformer implements Modifiers, Kinds {
 	return site.memberInfo(sym).derefDef();
     }
 
-    String infoString(Symbol sym, Type symtype, boolean lobound) {
+    String infoString(Symbol sym, Type symtype, int boundkind) {
 	switch (sym.kind) {
 	case ALIAS: return ", which equals " + symtype;
-	case TYPE:  return " bounded" + (lobound ? " from below" : "") + " by " + symtype;
+	case TYPE:  return " bounded" + (boundkind == LOBOUND ? " from below" : "") + " by " + symtype;
 	case VAL:   return " of type " + symtype;
 	default:    return "";
 	}
@@ -956,6 +968,7 @@ public class RefCheck extends Transformer implements Modifiers, Kinds {
 	case AbsTypeDef(_, _, _, _):
 	    validateVariance(sym, sym.info(), CoVariance);
 	    validateVariance(sym, sym.loBound(), ContraVariance);
+	    validateVariance(sym, sym.vuBound(), CoVariance);
 	    return super.transform(tree);
 
 	case AliasTypeDef(_, _, _, _):