diff -r dd9b5f767559 -r 2199365892b1 test/tools/javac/types/TypeHarness.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/tools/javac/types/TypeHarness.java	Mon Dec 13 14:56:50 2010 +0000
@@ -0,0 +1,315 @@
+/*
+ * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import com.sun.tools.javac.code.BoundKind;
+import com.sun.tools.javac.code.Flags;
+import com.sun.tools.javac.util.Context;
+import com.sun.tools.javac.code.Types;
+import com.sun.tools.javac.code.Symtab;
+import com.sun.tools.javac.code.Type;
+import com.sun.tools.javac.code.Type.*;
+import com.sun.tools.javac.code.Symbol.*;
+import com.sun.tools.javac.util.List;
+import com.sun.tools.javac.util.ListBuffer;
+import com.sun.tools.javac.util.Name;
+import com.sun.tools.javac.util.Names;
+import com.sun.tools.javac.file.JavacFileManager;
+
+/**
+ * Test harness whose goal is to simplify the task of writing type-system
+ * regression test. It provides functionalities to build custom types as well
+ * as to access the underlying javac's symbol table in order to retrieve
+ * predefined types. Among the features supported by the harness are: type
+ * substitution, type containment, subtyping, cast-conversion, assigment
+ * conversion.
+ *
+ * This class is meant to be a common super class for all concrete type test
+ * classes. A subclass can access the type-factory and the test methods so as
+ * to write compact tests. An example is reported below:
+ *
+ * <pre>
+ * Type X = fac.TypeVariable();
+ * Type Y = fac.TypeVariable();
+ * Type A_X_Y = fac.Class(0, X, Y);
+ * Type A_Obj_Obj = fac.Class(0,
+ *           predef.objectType,
+ *           predef.objectType);
+ * checkSameType(A_Obj_Obj, subst(A_X_Y,
+ *           Mapping(X, predef.objectType),
+ *           Mapping(Y, predef.objectType)));
+ * </pre>
+ *
+ * The above code is used to create two class types, namely {@code A<X,Y>} and
+ * {@code A<Object,Object>} where both {@code X} and {@code Y} are type-variables.
+ * The code then verifies that {@code [X:=Object,Y:=Object]A<X,Y> == A<Object,Object>}.
+ *
+ * @author mcimadamore
+ */
+public class TypeHarness {
+
+    protected Types types;
+    protected Symtab predef;
+    protected Names names;
+    protected Factory fac;
+
+    protected TypeHarness() {
+        Context ctx = new Context();
+        JavacFileManager.preRegister(ctx);
+        types = Types.instance(ctx);
+        predef = Symtab.instance(ctx);
+        names = Names.instance(ctx);
+        fac = new Factory();
+    }
+
+    // <editor-fold defaultstate="collapsed" desc="type assertions">
+
+    /** assert that 's' is a subtype of 't' */
+    public void assertSubtype(Type s, Type t) {
+        assertSubtype(s, t, true);
+    }
+
+    /** assert that 's' is/is not a subtype of 't' */
+    public void assertSubtype(Type s, Type t, boolean expected) {
+        if (types.isSubtype(s, t) != expected) {
+            String msg = expected ?
+                " is not a subtype of " :
+                " is a subtype of ";
+            error(s + msg + t);
+        }
+    }
+
+    /** assert that 's' is the same type as 't' */
+    public void assertSameType(Type s, Type t) {
+        assertSameType(s, t, true);
+    }
+
+    /** assert that 's' is/is not the same type as 't' */
+    public void assertSameType(Type s, Type t, boolean expected) {
+        if (types.isSameType(s, t) != expected) {
+            String msg = expected ?
+                " is not the same type as " :
+                " is the same type as ";
+            error(s + msg + t);
+        }
+    }
+
+    /** assert that 's' is castable to 't' */
+    public void assertCastable(Type s, Type t) {
+        assertCastable(s, t, true);
+    }
+
+    /** assert that 's' is/is not castable to 't' */
+    public void assertCastable(Type s, Type t, boolean expected) {
+        if (types.isCastable(s, t) != expected) {
+            String msg = expected ?
+                " is not castable to " :
+                " is castable to ";
+            error(s + msg + t);
+        }
+    }
+
+    /** assert that 's' is convertible (method invocation conversion) to 't' */
+    public void assertConvertible(Type s, Type t) {
+        assertCastable(s, t, true);
+    }
+
+    /** assert that 's' is/is not convertible (method invocation conversion) to 't' */
+    public void assertConvertible(Type s, Type t, boolean expected) {
+        if (types.isConvertible(s, t) != expected) {
+            String msg = expected ?
+                " is not convertible to " :
+                " is convertible to ";
+            error(s + msg + t);
+        }
+    }
+
+    /** assert that 's' is assignable to 't' */
+    public void assertAssignable(Type s, Type t) {
+        assertCastable(s, t, true);
+    }
+
+    /** assert that 's' is/is not assignable to 't' */
+    public void assertAssignable(Type s, Type t, boolean expected) {
+        if (types.isAssignable(s, t) != expected) {
+            String msg = expected ?
+                " is not assignable to " :
+                " is assignable to ";
+            error(s + msg + t);
+        }
+    }
+    // </editor-fold>
+
+    private void error(String msg) {
+        throw new AssertionError("Unexpected result: " + msg);
+    }
+
+    // <editor-fold defaultstate="collapsed" desc="type functions">
+
+    /** compute the erasure of a type 't' */
+    public Type erasure(Type t) {
+        return types.erasure(t);
+    }
+
+    /** compute the capture of a type 't' */
+    public Type capture(Type t) {
+        return types.capture(t);
+    }
+
+    /** compute the boxed type associated with 't' */
+    public Type box(Type t) {
+        if (!t.isPrimitive()) {
+            throw new AssertionError("Cannot box non-primitive type: " + t);
+        }
+        return types.boxedClass(t).type;
+    }
+
+    /** compute the unboxed type associated with 't' */
+    public Type unbox(Type t) {
+        Type u = types.unboxedType(t);
+        if (t == null) {
+            throw new AssertionError("Cannot unbox reference type: " + t);
+        } else {
+            return u;
+        }
+    }
+
+    /** compute a type substitution on 't' given a list of type mappings */
+    public Type subst(Type t, Mapping... maps) {
+        ListBuffer<Type> from = ListBuffer.lb();
+        ListBuffer<Type> to = ListBuffer.lb();
+        for (Mapping tm : maps) {
+            from.append(tm.from);
+            to.append(tm.to);
+        }
+        return types.subst(t, from.toList(), to.toList());
+    }
+
+    /** create a fresh type mapping from a type to another */
+    public Mapping Mapping(Type from, Type to) {
+        return new Mapping(from, to);
+    }
+
+    public static class Mapping {
+        Type from;
+        Type to;
+        private Mapping(Type from, Type to) {
+            this.from = from;
+            this.to = to;
+        }
+    }
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="type factory">
+
+    /**
+     * This class is used to create Java types in a simple way. All main
+     * kinds of type are supported: primitive, reference, non-denotable. The
+     * factory also supports creation of constant types (used by the compiler
+     * to represent the type of a literal).
+     */
+    public class Factory {
+
+        private int synthNameCount = 0;
+
+        private Name syntheticName() {
+            return names.fromString("A$" + synthNameCount++);
+        }
+
+        public ClassType Class(long flags, Type... typeArgs) {
+            ClassSymbol csym = new ClassSymbol(flags, syntheticName(), predef.noSymbol);
+            csym.type = new ClassType(Type.noType, List.from(typeArgs), csym);
+            ((ClassType)csym.type).supertype_field = predef.objectType;
+            return (ClassType)csym.type;
+        }
+
+        public ClassType Class(Type... typeArgs) {
+            return Class(0, typeArgs);
+        }
+
+        public ClassType Interface(Type... typeArgs) {
+            return Class(Flags.INTERFACE, typeArgs);
+        }
+
+        public ClassType Interface(long flags, Type... typeArgs) {
+            return Class(Flags.INTERFACE | flags, typeArgs);
+        }
+
+        public Type Constant(byte b) {
+            return predef.byteType.constType(b);
+        }
+
+        public Type Constant(short s) {
+            return predef.shortType.constType(s);
+        }
+
+        public Type Constant(int i) {
+            return predef.intType.constType(i);
+        }
+
+        public Type Constant(long l) {
+            return predef.longType.constType(l);
+        }
+
+        public Type Constant(float f) {
+            return predef.floatType.constType(f);
+        }
+
+        public Type Constant(double d) {
+            return predef.doubleType.constType(d);
+        }
+
+        public Type Constant(char c) {
+            return predef.charType.constType(c + 0);
+        }
+
+        public ArrayType Array(Type elemType) {
+            return new ArrayType(elemType, predef.arrayClass);
+        }
+
+        public TypeVar TypeVariable() {
+            return TypeVariable(predef.objectType);
+        }
+
+        public TypeVar TypeVariable(Type bound) {
+            TypeSymbol tvsym = new TypeSymbol(0, syntheticName(), null, predef.noSymbol);
+            tvsym.type = new TypeVar(tvsym, bound, null);
+            return (TypeVar)tvsym.type;
+        }
+
+        public WildcardType Wildcard(BoundKind bk, Type bound) {
+            return new WildcardType(bound, bk, predef.boundClass);
+        }
+
+        public CapturedType CapturedVariable(Type upper, Type lower) {
+            return new CapturedType(syntheticName(), predef.noSymbol, upper, lower, null);
+        }
+
+        public ClassType Intersection(Type classBound, Type... intfBounds) {
+            ClassType ct = Class(Flags.COMPOUND);
+            ct.supertype_field = classBound;
+            ct.interfaces_field = List.from(intfBounds);
+            return ct;
+        }
+    }
+    // </editor-fold>
+}