123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365 |
- package org.aspectj.apache.bcel.generic;
-
- /* ====================================================================
- * The Apache Software License, Version 1.1
- *
- * Copyright (c) 2001 The Apache Software Foundation. All rights
- * reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. The end-user documentation included with the redistribution,
- * if any, must include the following acknowledgment:
- * "This product includes software developed by the
- * Apache Software Foundation (http://www.apache.org/)."
- * Alternately, this acknowledgment may appear in the software itself,
- * if and wherever such third-party acknowledgments normally appear.
- *
- * 4. The names "Apache" and "Apache Software Foundation" and
- * "Apache BCEL" must not be used to endorse or promote products
- * derived from this software without prior written permission. For
- * written permission, please contact apache@apache.org.
- *
- * 5. Products derived from this software may not be called "Apache",
- * "Apache BCEL", nor may "Apache" appear in their name, without
- * prior written permission of the Apache Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- * ====================================================================
- *
- * This software consists of voluntary contributions made by many
- * individuals on behalf of the Apache Software Foundation. For more
- * information on the Apache Software Foundation, please see
- * <http://www.apache.org/>.
- */
-
- import org.aspectj.apache.bcel.Constants;
- import org.aspectj.apache.bcel.Repository;
- import org.aspectj.apache.bcel.classfile.JavaClass;
-
- /**
- * Super class for object and array types.
- *
- * @version $Id: ReferenceType.java,v 1.6 2009/09/09 22:18:20 aclement Exp $
- * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
- */
- public abstract class ReferenceType extends Type {
-
- protected ReferenceType(byte t, String s) {
- super(t, s);
- }
-
- ReferenceType() {
- super(Constants.T_OBJECT, "<null object>");
- }
-
- /**
- * Return true iff this type is castable to another type t as defined in the JVM specification. The case where this is Type.NULL
- * is not defined (see the CHECKCAST definition in the JVM specification). However, because e.g. CHECKCAST doesn't throw a
- * ClassCastException when casting a null reference to any Object, true is returned in this case.
- */
- public boolean isCastableTo(Type t) {
- if (this.equals(Type.NULL)) {
- return true; // If this is ever changed in isAssignmentCompatible()
- }
-
- return isAssignmentCompatibleWith(t);
- /*
- * Yes, it's true: It's the same definition. See vmspec2 AASTORE / CHECKCAST definitions.
- */
- }
-
- /**
- * Return true iff this is assignment compatible with another type t as defined in the JVM specification; see the AASTORE
- * definition there.
- */
- public boolean isAssignmentCompatibleWith(Type t) {
- if (!(t instanceof ReferenceType)) {
- return false;
- }
-
- ReferenceType T = (ReferenceType) t;
-
- if (this.equals(Type.NULL)) {
- return true; // This is not explicitely stated, but clear. Isn't it?
- }
-
- /*
- * If this is a class type then
- */
- if (this instanceof ObjectType && ((ObjectType) this).referencesClass()) {
- /*
- * If T is a class type, then this must be the same class as T, or this must be a subclass of T;
- */
- if (T instanceof ObjectType && ((ObjectType) T).referencesClass()) {
- if (this.equals(T)) {
- return true;
- }
-
- if (Repository.instanceOf(((ObjectType) this).getClassName(), ((ObjectType) T).getClassName())) {
- return true;
- }
- }
-
- /*
- * If T is an interface type, this must implement interface T.
- */
- if (T instanceof ObjectType && ((ObjectType) T).referencesInterface()) {
- if (Repository.implementationOf(((ObjectType) this).getClassName(), ((ObjectType) T).getClassName())) {
- return true;
- }
- }
- }
-
- /*
- * If this is an interface type, then:
- */
- if (this instanceof ObjectType && ((ObjectType) this).referencesInterface()) {
- /*
- * If T is a class type, then T must be Object (2.4.7).
- */
- if (T instanceof ObjectType && ((ObjectType) T).referencesClass()) {
- if (T.equals(Type.OBJECT)) {
- return true;
- }
- }
-
- /*
- * If T is an interface type, then T must be the same interface as this or a superinterface of this (2.13.2).
- */
- if (T instanceof ObjectType && ((ObjectType) T).referencesInterface()) {
- if (this.equals(T)) {
- return true;
- }
- if (Repository.implementationOf(((ObjectType) this).getClassName(), ((ObjectType) T).getClassName())) {
- return true;
- }
- }
- }
-
- /*
- * If this is an array type, namely, the type SC[], that is, an array of components of type SC, then:
- */
- if (this instanceof ArrayType) {
- /*
- * If T is a class type, then T must be Object (2.4.7).
- */
- if (T instanceof ObjectType && ((ObjectType) T).referencesClass()) {
- if (T.equals(Type.OBJECT)) {
- return true;
- }
- }
-
- /*
- * If T is an array type TC[], that is, an array of components of type TC, then one of the following must be true:
- */
- if (T instanceof ArrayType) {
- /*
- * TC and SC are the same primitive type (2.4.1).
- */
- Type sc = ((ArrayType) this).getElementType();
- Type tc = ((ArrayType) this).getElementType();
-
- if (sc instanceof BasicType && tc instanceof BasicType && sc.equals(tc)) {
- return true;
- }
-
- /*
- * TC and SC are reference types (2.4.6), and type SC is assignable to TC by these runtime rules.
- */
- if (tc instanceof ReferenceType && sc instanceof ReferenceType
- && ((ReferenceType) sc).isAssignmentCompatibleWith(tc)) {
- return true;
- }
- }
-
- /* If T is an interface type, T must be one of the interfaces implemented by arrays (2.15). */
- // TODO: Check if this is still valid or find a way to dynamically find out which
- // interfaces arrays implement. However, as of the JVM specification edition 2, there
- // are at least two different pages where assignment compatibility is defined and
- // on one of them "interfaces implemented by arrays" is exchanged with "'Cloneable' or
- // 'java.io.Serializable'"
- if (T instanceof ObjectType && ((ObjectType) T).referencesInterface()) {
- for (int ii = 0; ii < Constants.INTERFACES_IMPLEMENTED_BY_ARRAYS.length; ii++) {
- if (T.equals(new ObjectType(Constants.INTERFACES_IMPLEMENTED_BY_ARRAYS[ii]))) {
- return true;
- }
- }
- }
- }
- return false; // default.
- }
-
- /**
- * This commutative operation returns the first common superclass (narrowest ReferenceType referencing a class, not an
- * interface). If one of the types is a superclass of the other, the former is returned. If "this" is Type.NULL, then t is
- * returned. If t is Type.NULL, then "this" is returned. If "this" equals t ['this.equals(t)'] "this" is returned. If "this" or
- * t is an ArrayType, then Type.OBJECT is returned; unless their dimensions match. Then an ArrayType of the same number of
- * dimensions is returned, with its basic type being the first common super class of the basic types of "this" and t. If "this"
- * or t is a ReferenceType referencing an interface, then Type.OBJECT is returned. If not all of the two classes' superclasses
- * cannot be found, "null" is returned. See the JVM specification edition 2, "4.9.2 The Bytecode Verifier".
- */
- public ReferenceType getFirstCommonSuperclass(ReferenceType t) {
- if (this.equals(Type.NULL)) {
- return t;
- }
- if (t.equals(Type.NULL)) {
- return this;
- }
- if (this.equals(t)) {
- return this;
- /*
- * TODO: Above sounds a little arbitrary. On the other hand, there is no object referenced by Type.NULL so we can also
- * say all the objects referenced by Type.NULL were derived from java.lang.Object. However, the Java Language's
- * "instanceof" operator proves us wrong: "null" is not referring to an instance of java.lang.Object :)
- */
- }
-
- /* This code is from a bug report by Konstantin Shagin <konst@cs.technion.ac.il> */
-
- if (this instanceof ArrayType && t instanceof ArrayType) {
- ArrayType arrType1 = (ArrayType) this;
- ArrayType arrType2 = (ArrayType) t;
- if (arrType1.getDimensions() == arrType2.getDimensions() && arrType1.getBasicType() instanceof ObjectType
- && arrType2.getBasicType() instanceof ObjectType) {
- return new ArrayType(((ObjectType) arrType1.getBasicType()).getFirstCommonSuperclass((ObjectType) arrType2
- .getBasicType()), arrType1.getDimensions());
-
- }
- }
-
- if (this instanceof ArrayType || t instanceof ArrayType) {
- return Type.OBJECT;
- // TODO: Is there a proof of OBJECT being the direct ancestor of every ArrayType?
- }
-
- if (this instanceof ObjectType && ((ObjectType) this).referencesInterface() || t instanceof ObjectType
- && ((ObjectType) t).referencesInterface()) {
- return Type.OBJECT;
- // TODO: The above line is correct comparing to the vmspec2. But one could
- // make class file verification a bit stronger here by using the notion of
- // superinterfaces or even castability or assignment compatibility.
- }
-
- // this and t are ObjectTypes, see above.
- ObjectType thiz = (ObjectType) this;
- ObjectType other = (ObjectType) t;
- JavaClass[] thiz_sups = Repository.lookupClass(thiz.getClassName()).getSuperClasses();// getSuperClasses(thiz.getClassName());
- JavaClass[] other_sups = Repository.lookupClass(other.getClassName()).getSuperClasses();// getSuperClasses(other.getClassName());
-
- if (thiz_sups == null || other_sups == null) {
- return null;
- }
-
- // Waaahh...
- JavaClass[] this_sups = new JavaClass[thiz_sups.length + 1];
- JavaClass[] t_sups = new JavaClass[other_sups.length + 1];
- System.arraycopy(thiz_sups, 0, this_sups, 1, thiz_sups.length);
- System.arraycopy(other_sups, 0, t_sups, 1, other_sups.length);
- this_sups[0] = Repository.lookupClass(thiz.getClassName());
- t_sups[0] = Repository.lookupClass(other.getClassName());
-
- for (JavaClass t_sup : t_sups) {
- for (JavaClass this_sup : this_sups) {
- if (this_sup.equals(t_sup)) {
- return new ObjectType(this_sup.getClassName());
- }
- }
- }
-
- // Huh? Did you ask for Type.OBJECT's superclass??
- return null;
- }
-
- // /**
- // * This commutative operation returns the first common superclass (narrowest ReferenceType referencing a class, not an
- // * interface). If one of the types is a superclass of the other, the former is returned. If "this" is Type.NULL, then t is
- // * returned. If t is Type.NULL, then "this" is returned. If "this" equals t ['this.equals(t)'] "this" is returned. If "this"
- // or
- // * t is an ArrayType, then Type.OBJECT is returned. If "this" or t is a ReferenceType referencing an interface, then
- // Type.OBJECT
- // * is returned. If not all of the two classes' superclasses cannot be found, "null" is returned. See the JVM specification
- // * edition 2, "4.9.2 The Bytecode Verifier".
- // *
- // * @deprecated use getFirstCommonSuperclass(ReferenceType t) which has slightly changed semantics.
- // */
- // public ReferenceType firstCommonSuperclass(ReferenceType t) {
- // if (this.equals(Type.NULL)) {
- // return t;
- // }
- // if (t.equals(Type.NULL)) {
- // return this;
- // }
- // if (this.equals(t)) {
- // return this;
- // /*
- // * TODO: Above sounds a little arbitrary. On the other hand, there is no object referenced by Type.NULL so we can also
- // * say all the objects referenced by Type.NULL were derived from java.lang.Object. However, the Java Language's
- // * "instanceof" operator proves us wrong: "null" is not referring to an instance of java.lang.Object :)
- // */
- // }
- //
- // if (this instanceof ArrayType || t instanceof ArrayType) {
- // return Type.OBJECT;
- // // TODO: Is there a proof of OBJECT being the direct ancestor of every ArrayType?
- // }
- //
- // if (this instanceof ObjectType && ((ObjectType) this).referencesInterface() || t instanceof ObjectType
- // && ((ObjectType) t).referencesInterface()) {
- // return Type.OBJECT;
- // // TODO: The above line is correct comparing to the vmspec2. But one could
- // // make class file verification a bit stronger here by using the notion of
- // // superinterfaces or even castability or assignment compatibility.
- // }
- //
- // // this and t are ObjectTypes, see above.
- // ObjectType thiz = (ObjectType) this;
- // ObjectType other = (ObjectType) t;
- // JavaClass[] thiz_sups = Repository.getSuperClasses(thiz.getClassName());
- // JavaClass[] other_sups = Repository.getSuperClasses(other.getClassName());
- //
- // if (thiz_sups == null || other_sups == null) {
- // return null;
- // }
- //
- // // Waaahh...
- // JavaClass[] this_sups = new JavaClass[thiz_sups.length + 1];
- // JavaClass[] t_sups = new JavaClass[other_sups.length + 1];
- // System.arraycopy(thiz_sups, 0, this_sups, 1, thiz_sups.length);
- // System.arraycopy(other_sups, 0, t_sups, 1, other_sups.length);
- // this_sups[0] = Repository.lookupClass(thiz.getClassName());
- // t_sups[0] = Repository.lookupClass(other.getClassName());
- //
- // for (int i = 0; i < t_sups.length; i++) {
- // for (int j = 0; j < this_sups.length; j++) {
- // if (this_sups[j].equals(t_sups[i])) {
- // return new ObjectType(this_sups[j].getClassName());
- // }
- // }
- // }
- //
- // // Huh? Did you ask for Type.OBJECT's superclass??
- // return null;
- // }
- }
|