Initial revision

git-svn-id: https://svn.code.sf.net/p/jode/code/trunk@418 379699f6-c40d-0410-875b-85095c16579e

jode/jode/type/ReferenceType.java

@@ -0,0 +1,119 @@
+/* ReferenceType Copyright (C) 1997-1998 Jochen Hoenicke.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id$
+ */
+package jode;
+import jode.bytecode.ClassInfo;
+import java.util.Vector;
+import java.util.Stack;
+
+/**
+ * This is an abstrace super class of all reference types.  Reference
+ * types are ClassInterfacesType, ArrayType and NullType. <p>
+ *
+ * @author Jochen Hoenicke 
+ */
+public abstract class ReferenceType extends Type {
+    public ReferenceType(int typecode) {
+	super(typecode);
+    }
+    
+    /**
+     * Returns the specialized type of this and type. 
+     * The result should be the Type that extends both Types
+     * (this and type).  This correspondents to the common bottom Type
+     * in a range type.
+     * @param type the other type.
+     * @return the specialized type.
+     */
+    public abstract Type getSpecializedType(Type typ);
+    /**
+     * Returns the generalized type of this and type.  The result
+     * should be the types that both types extends or implements. This
+     * correspondents to the common top Type in a range type.
+     * @param type the other type.
+     * @return the generalized type
+     */
+    public abstract Type getGeneralizedType(Type typ);
+    public abstract Type createRangeType(ReferenceType bottom);
+
+    /**
+     * Tells if all otherIfaces, are implemented by at least one
+     * ifaces or by clazz.
+     * 
+     * This is a useful function for generalizing/specializing interface
+     * types or arrays.
+     * @param clazz The clazz, can be null.
+     * @param ifaces The ifaces.
+     * @param otherifaces The other ifaces, that must be implemented.
+     * @return true, if all otherIfaces are implemented.
+     */
+    protected static boolean implementsAllIfaces(ClassInfo clazz,
+						 ClassInfo[] ifaces,
+						 ClassInfo[] otherIfaces) {
+    big:
+        for (int i=0; i < otherIfaces.length; i++) {
+            ClassInfo iface = otherIfaces[i];
+            if (clazz != null && iface.implementedBy(clazz))
+                continue big;
+            for (int j=0; j < ifaces.length; j++) {
+                if (iface.implementedBy(ifaces[j]))
+                        continue big;
+            }
+            return false;
+        }
+        return true;
+    }
+
+    public Type getSuperType() {
+	return (this == tObject) ? tObject : tRange(tObject, this);
+    }
+
+    public Type getSubType() {
+        return tRange(this, tNull);
+    }
+
+    /**
+     * Intersect this type with another type and return the new type.
+     * @param type the other type.
+     * @return the intersection, or tError, if a type conflict happens.
+     */
+    public Type intersection(Type type) {
+	if (type == tError)
+	    return type;
+	if (type == Type.tUnknown)
+	    return this;
+
+	Type newBottom = getSpecializedType(type);
+	Type newTop    = getGeneralizedType(type);
+	Type result;
+	if (newTop.equals(newBottom))
+	    result = newTop;
+	else if (newTop instanceof ReferenceType
+		 && newBottom instanceof ReferenceType)
+	    result = ((ReferenceType) newTop)
+		.createRangeType((ReferenceType) newBottom);
+	else
+	    result = tError;
+
+        if (Decompiler.isTypeDebugging) {
+	    Decompiler.err.println("intersecting "+ this +" and "+ type + 
+                                   " to " + result);
+	}	    
+        return result;
+    }
+}