package org.aspectj.apache.bcel.verifier.statics;
/* ====================================================================
* 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
* .
*/
import java.util.HashMap;
import java.util.HashSet;
import org.aspectj.apache.bcel.Constants;
import org.aspectj.apache.bcel.Repository;
import org.aspectj.apache.bcel.classfile.Attribute;
import org.aspectj.apache.bcel.classfile.Code;
import org.aspectj.apache.bcel.classfile.CodeException;
import org.aspectj.apache.bcel.classfile.Constant;
import org.aspectj.apache.bcel.classfile.ConstantClass;
import org.aspectj.apache.bcel.classfile.ConstantDouble;
import org.aspectj.apache.bcel.classfile.ConstantFieldref;
import org.aspectj.apache.bcel.classfile.ConstantFloat;
import org.aspectj.apache.bcel.classfile.ConstantInteger;
import org.aspectj.apache.bcel.classfile.ConstantInterfaceMethodref;
import org.aspectj.apache.bcel.classfile.ConstantLong;
import org.aspectj.apache.bcel.classfile.ConstantMethodref;
import org.aspectj.apache.bcel.classfile.ConstantNameAndType;
import org.aspectj.apache.bcel.classfile.ConstantPool;
import org.aspectj.apache.bcel.classfile.ConstantString;
import org.aspectj.apache.bcel.classfile.ConstantUtf8;
import org.aspectj.apache.bcel.classfile.ConstantValue;
import org.aspectj.apache.bcel.classfile.Deprecated;
import org.aspectj.apache.bcel.classfile.ExceptionTable;
import org.aspectj.apache.bcel.classfile.Field;
import org.aspectj.apache.bcel.classfile.InnerClass;
import org.aspectj.apache.bcel.classfile.InnerClasses;
import org.aspectj.apache.bcel.classfile.JavaClass;
import org.aspectj.apache.bcel.classfile.LineNumber;
import org.aspectj.apache.bcel.classfile.LineNumberTable;
import org.aspectj.apache.bcel.classfile.LocalVariable;
import org.aspectj.apache.bcel.classfile.LocalVariableTable;
import org.aspectj.apache.bcel.classfile.Method;
import org.aspectj.apache.bcel.classfile.Node;
import org.aspectj.apache.bcel.classfile.SourceFile;
import org.aspectj.apache.bcel.classfile.Synthetic;
import org.aspectj.apache.bcel.classfile.Unknown;
import org.aspectj.apache.bcel.generic.ArrayType;
import org.aspectj.apache.bcel.generic.ObjectType;
import org.aspectj.apache.bcel.generic.Type;
import org.aspectj.apache.bcel.verifier.DescendingVisitor;
import org.aspectj.apache.bcel.verifier.EmptyClassVisitor;
import org.aspectj.apache.bcel.verifier.PassVerifier;
import org.aspectj.apache.bcel.verifier.VerificationResult;
import org.aspectj.apache.bcel.verifier.Verifier;
import org.aspectj.apache.bcel.verifier.VerifierFactory;
import org.aspectj.apache.bcel.verifier.exc.AssertionViolatedException;
import org.aspectj.apache.bcel.verifier.exc.ClassConstraintException;
import org.aspectj.apache.bcel.verifier.exc.LocalVariableInfoInconsistentException;
/**
* This PassVerifier verifies a class file according to pass 2 as described in The Java Virtual Machine Specification, 2nd edition.
* More detailed information is to be found at the do_verify() method's documentation.
*
* @version $Id: Pass2Verifier.java,v 1.5 2009/09/10 15:35:05 aclement Exp $
* @author Enver Haase
* @see #do_verify()
*/
public final class Pass2Verifier extends PassVerifier implements Constants {
/**
* The LocalVariableInfo instances used by Pass3bVerifier. localVariablesInfos[i] denotes the information for the local
* variables of method number i in the JavaClass this verifier operates on.
*/
private LocalVariablesInfo[] localVariablesInfos;
/** The Verifier that created this. */
private Verifier myOwner;
/**
* Should only be instantiated by a Verifier.
*
* @see Verifier
*/
public Pass2Verifier(Verifier owner) {
myOwner = owner;
}
/**
* Returns a LocalVariablesInfo object containing information about the usage of the local variables in the Code attribute of
* the said method or null if the class file this Pass2Verifier operates on could not be pass-2-verified correctly. The
* method number method_nr is the method you get using
* Repository.lookupClass(myOwner.getClassname()).getMethods()[method_nr];. You should not add own information. Leave
* that to JustIce.
*/
public LocalVariablesInfo getLocalVariablesInfo(int method_nr) {
if (this.verify() != VerificationResult.VR_OK)
return null; // It's cached, don't worry.
if (method_nr < 0 || method_nr >= localVariablesInfos.length) {
throw new AssertionViolatedException("Method number out of range.");
}
return localVariablesInfos[method_nr];
}
/**
* Pass 2 is the pass where static properties of the class file are checked without looking into "Code" arrays of methods. This
* verification pass is usually invoked when a class is resolved; and it may be possible that this verification pass has to load
* in other classes such as superclasses or implemented interfaces. Therefore, Pass 1 is run on them.
* Note that most referenced classes are not loaded in for verification or for an existance check by this pass; only the
* syntactical correctness of their names and descriptors (a.k.a. signatures) is checked.
* Very few checks that conceptually belong here are delayed until pass 3a in JustIce. JustIce does not only check for
* syntactical correctness but also for semantical sanity - therefore it needs access to the "Code" array of methods in a few
* cases. Please see the pass 3a documentation, too.
*
* @see org.aspectj.apache.bcel.verifier.statics.Pass3aVerifier
*/
@Override
public VerificationResult do_verify() {
VerificationResult vr1 = myOwner.doPass1();
if (vr1.equals(VerificationResult.VR_OK)) {
// For every method, we could have information about the local variables out of LocalVariableTable attributes of
// the Code attributes.
localVariablesInfos = new LocalVariablesInfo[Repository.lookupClass(myOwner.getClassName()).getMethods().length];
VerificationResult vr = VerificationResult.VR_OK; // default.
try {
constant_pool_entries_satisfy_static_constraints();
field_and_method_refs_are_valid();
every_class_has_an_accessible_superclass();
final_methods_are_not_overridden();
} catch (ClassConstraintException cce) {
vr = new VerificationResult(VerificationResult.VERIFIED_REJECTED, cce.getMessage());
}
return vr;
} else
return VerificationResult.VR_NOTYET;
}
/**
* Ensures that every class has a super class and that final classes are not subclassed. This means, the class this
* Pass2Verifier operates on has proper super classes (transitively) up to java.lang.Object. The reason for really loading (and
* Pass1-verifying) all of those classes here is that we need them in Pass2 anyway to verify no final methods are overridden
* (that could be declared anywhere in the ancestor hierarchy).
*
* @throws ClassConstraintException otherwise.
*/
private void every_class_has_an_accessible_superclass() {
HashSet hs = new HashSet(); // save class names to detect circular inheritance
JavaClass jc = Repository.lookupClass(myOwner.getClassName());
int supidx = -1;
while (supidx != 0) {
supidx = jc.getSuperclassNameIndex();
if (supidx == 0) {
if (jc != Repository.lookupClass(Type.OBJECT.getClassName())) {
throw new ClassConstraintException("Superclass of '" + jc.getClassName() + "' missing but not "
+ Type.OBJECT.getClassName() + " itself!");
}
} else {
String supername = jc.getSuperclassName();
if (!hs.add(supername)) { // If supername already is in the list
throw new ClassConstraintException("Circular superclass hierarchy detected.");
}
Verifier v = VerifierFactory.getVerifier(supername);
VerificationResult vr = v.doPass1();
if (vr != VerificationResult.VR_OK) {
throw new ClassConstraintException("Could not load in ancestor class '" + supername + "'.");
}
jc = Repository.lookupClass(supername);
if (jc.isFinal()) {
throw new ClassConstraintException("Ancestor class '" + supername
+ "' has the FINAL access modifier and must therefore not be subclassed.");
}
}
}
}
/**
* Ensures that final methods are not overridden. Precondition to run this method:
* constant_pool_entries_satisfy_static_constraints() and every_class_has_an_accessible_superclass() have to be invoked before
* (in that order).
*
* @throws ClassConstraintException otherwise.
* @see #constant_pool_entries_satisfy_static_constraints()
* @see #every_class_has_an_accessible_superclass()
*/
private void final_methods_are_not_overridden() {
HashMap hashmap = new HashMap();
JavaClass jc = Repository.lookupClass(myOwner.getClassName());
int supidx = -1;
while (supidx != 0) {
supidx = jc.getSuperclassNameIndex();
Method[] methods = jc.getMethods();
for (int i = 0; i < methods.length; i++) {
String name_and_sig = (methods[i].getName() + methods[i].getSignature());
if (hashmap.containsKey(name_and_sig)) {
if (methods[i].isFinal()) {
throw new ClassConstraintException("Method '" + name_and_sig + "' in class '" + hashmap.get(name_and_sig)
+ "' overrides the final (not-overridable) definition in class '" + jc.getClassName() + "'.");
} else {
if (!methods[i].isStatic()) { // static methods don't inherit
hashmap.put(name_and_sig, jc.getClassName());
}
}
} else {
if (!methods[i].isStatic()) { // static methods don't inherit
hashmap.put(name_and_sig, jc.getClassName());
}
}
}
jc = Repository.lookupClass(jc.getSuperclassName()); // Well, for OBJECT this returns OBJECT so it works (could return
// anything but must not throw an Exception).
}
}
/**
* Ensures that the constant pool entries satisfy the static constraints as described in The Java Virtual Machine Specification,
* 2nd Edition.
*
* @throws ClassConstraintException otherwise.
*/
private void constant_pool_entries_satisfy_static_constraints() {
// Most of the consistency is handled internally by BCEL; here
// we only have to verify if the indices of the constants point
// to constants of the appropriate type and such.
JavaClass jc = Repository.lookupClass(myOwner.getClassName());
new CPESSC_Visitor(jc); // constructor implicitely traverses jc
}
/**
* A Visitor class that ensures the constant pool satisfies the static constraints. The visitXXX() methods throw
* ClassConstraintException instances otherwise.
*
* @see #constant_pool_entries_satisfy_static_constraints()
*/
private class CPESSC_Visitor extends org.aspectj.apache.bcel.verifier.EmptyClassVisitor {
private Class CONST_Class;
/*
* private Class CONST_Fieldref; private Class CONST_Methodref; private Class CONST_InterfaceMethodref;
*/
private Class CONST_String;
private Class CONST_Integer;
private Class CONST_Float;
private Class CONST_Long;
private Class CONST_Double;
private Class CONST_NameAndType;
private Class CONST_Utf8;
private final JavaClass jc;
private final ConstantPool cp; // ==jc.getConstantPool() -- only here to save typing work and computing power.
private final int cplen; // == cp.getLength() -- to save computing power.
private DescendingVisitor carrier;
private HashSet field_names = new HashSet();
private HashSet field_names_and_desc = new HashSet();
private HashSet method_names_and_desc = new HashSet();
private CPESSC_Visitor(JavaClass _jc) {
jc = _jc;
cp = _jc.getConstantPool();
cplen = cp.getLength();
CONST_Class = org.aspectj.apache.bcel.classfile.ConstantClass.class;
/*
* CONST_Fieldref = org.aspectj.apache.bcel.classfile.ConstantFieldref.class; CONST_Methodref =
* org.aspectj.apache.bcel.classfile.ConstantMethodref.class; CONST_InterfaceMethodref =
* org.aspectj.apache.bcel.classfile.ConstantInterfaceMethodref.class;
*/
CONST_String = org.aspectj.apache.bcel.classfile.ConstantString.class;
CONST_Integer = org.aspectj.apache.bcel.classfile.ConstantInteger.class;
CONST_Float = org.aspectj.apache.bcel.classfile.ConstantFloat.class;
CONST_Long = org.aspectj.apache.bcel.classfile.ConstantLong.class;
CONST_Double = org.aspectj.apache.bcel.classfile.ConstantDouble.class;
CONST_NameAndType = org.aspectj.apache.bcel.classfile.ConstantNameAndType.class;
CONST_Utf8 = org.aspectj.apache.bcel.classfile.ConstantUtf8.class;
carrier = new DescendingVisitor(_jc, this);
carrier.visit();
}
private void checkIndex(Node referrer, int index, Class shouldbe) {
if ((index < 0) || (index >= cplen)) {
throw new ClassConstraintException("Invalid index '" + index + "' used by '" + tostring(referrer) + "'.");
}
Constant c = cp.getConstant(index);
if (!shouldbe.isInstance(c)) {
/* String isnot = shouldbe.toString().substring(shouldbe.toString().lastIndexOf(".")+1); //Cut all before last "." */
throw new ClassCastException("Illegal constant '" + tostring(c) + "' at index '" + index + "'. '"
+ tostring(referrer) + "' expects a '" + shouldbe + "'.");
}
}
// /////////////////////////////////////
// ClassFile structure (vmspec2 4.1) //
// /////////////////////////////////////
@Override
public void visitJavaClass(JavaClass obj) {
Attribute[] atts = obj.getAttributes();
boolean foundSourceFile = false;
boolean foundInnerClasses = false;
// Is there an InnerClass referenced?
// This is a costly check; existing verifiers don't do it!
boolean hasInnerClass = new InnerClassDetector(jc).innerClassReferenced();
for (int i = 0; i < atts.length; i++) {
if ((!(atts[i] instanceof SourceFile)) && (!(atts[i] instanceof Deprecated))
&& (!(atts[i] instanceof InnerClasses)) && (!(atts[i] instanceof Synthetic))) {
addMessage("Attribute '" + tostring(atts[i]) + "' as an attribute of the ClassFile structure '" + tostring(obj)
+ "' is unknown and will therefore be ignored.");
}
if (atts[i] instanceof SourceFile) {
if (foundSourceFile == false)
foundSourceFile = true;
else
throw new ClassConstraintException("A ClassFile structure (like '" + tostring(obj)
+ "') may have no more than one SourceFile attribute."); // vmspec2 4.7.7
}
if (atts[i] instanceof InnerClasses) {
if (foundInnerClasses == false)
foundInnerClasses = true;
else {
if (hasInnerClass) {
throw new ClassConstraintException(
"A Classfile structure (like '"
+ tostring(obj)
+ "') must have exactly one InnerClasses attribute if at least one Inner Class is referenced (which is the case). More than one InnerClasses attribute was found.");
}
}
if (!hasInnerClass) {
addMessage("No referenced Inner Class found, but InnerClasses attribute '" + tostring(atts[i])
+ "' found. Strongly suggest removal of that attribute.");
}
}
}
if (hasInnerClass && !foundInnerClasses) {
// throw new
// ClassConstraintException("A Classfile structure (like '"+tostring(obj)+"') must have exactly one InnerClasses attribute if at least one Inner Class is referenced (which is the case). No InnerClasses attribute was found.");
// vmspec2, page 125 says it would be a constraint: but existing verifiers
// don't check it and javac doesn't satisfy it when it comes to anonymous
// inner classes
addMessage("A Classfile structure (like '"
+ tostring(obj)
+ "') must have exactly one InnerClasses attribute if at least one Inner Class is referenced (which is the case). No InnerClasses attribute was found.");
}
}
// ///////////////////////////
// CONSTANTS (vmspec2 4.4) //
// ///////////////////////////
@Override
public void visitConstantClass(ConstantClass obj) {
if (obj.getTag() != Constants.CONSTANT_Class) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
}
@Override
public void visitConstantFieldref(ConstantFieldref obj) {
if (obj.getTag() != Constants.CONSTANT_Fieldref) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
checkIndex(obj, obj.getClassIndex(), CONST_Class);
checkIndex(obj, obj.getNameAndTypeIndex(), CONST_NameAndType);
}
@Override
public void visitConstantMethodref(ConstantMethodref obj) {
if (obj.getTag() != Constants.CONSTANT_Methodref) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
checkIndex(obj, obj.getClassIndex(), CONST_Class);
checkIndex(obj, obj.getNameAndTypeIndex(), CONST_NameAndType);
}
@Override
public void visitConstantInterfaceMethodref(ConstantInterfaceMethodref obj) {
if (obj.getTag() != Constants.CONSTANT_InterfaceMethodref) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
checkIndex(obj, obj.getClassIndex(), CONST_Class);
checkIndex(obj, obj.getNameAndTypeIndex(), CONST_NameAndType);
}
@Override
public void visitConstantString(ConstantString obj) {
if (obj.getTag() != Constants.CONSTANT_String) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
checkIndex(obj, obj.getStringIndex(), CONST_Utf8);
}
@Override
public void visitConstantInteger(ConstantInteger obj) {
if (obj.getTag() != Constants.CONSTANT_Integer) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
// no indices to check
}
@Override
public void visitConstantFloat(ConstantFloat obj) {
if (obj.getTag() != Constants.CONSTANT_Float) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
// no indices to check
}
@Override
public void visitConstantLong(ConstantLong obj) {
if (obj.getTag() != Constants.CONSTANT_Long) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
// no indices to check
}
@Override
public void visitConstantDouble(ConstantDouble obj) {
if (obj.getTag() != Constants.CONSTANT_Double) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
// no indices to check
}
@Override
public void visitConstantNameAndType(ConstantNameAndType obj) {
if (obj.getTag() != Constants.CONSTANT_NameAndType) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
// checkIndex(obj, obj.getDescriptorIndex(), CONST_Utf8); //inconsistently named in BCEL, see below.
checkIndex(obj, obj.getSignatureIndex(), CONST_Utf8);
}
@Override
public void visitConstantUtf8(ConstantUtf8 obj) {
if (obj.getTag() != Constants.CONSTANT_Utf8) {
throw new ClassConstraintException("Wrong constant tag in '" + tostring(obj) + "'.");
}
// no indices to check
}
// ////////////////////////
// FIELDS (vmspec2 4.5) //
// ////////////////////////
@Override
public void visitField(Field obj) {
if (jc.isClass()) {
int maxone = 0;
if (obj.isPrivate())
maxone++;
if (obj.isProtected())
maxone++;
if (obj.isPublic())
maxone++;
if (maxone > 1) {
throw new ClassConstraintException("Field '" + tostring(obj)
+ "' must only have at most one of its ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC modifiers set.");
}
if (obj.isFinal() && obj.isVolatile()) {
throw new ClassConstraintException("Field '" + tostring(obj)
+ "' must only have at most one of its ACC_FINAL, ACC_VOLATILE modifiers set.");
}
} else { // isInterface!
if (!obj.isPublic()) {
throw new ClassConstraintException("Interface field '" + tostring(obj)
+ "' must have the ACC_PUBLIC modifier set but hasn't!");
}
if (!obj.isStatic()) {
throw new ClassConstraintException("Interface field '" + tostring(obj)
+ "' must have the ACC_STATIC modifier set but hasn't!");
}
if (!obj.isFinal()) {
throw new ClassConstraintException("Interface field '" + tostring(obj)
+ "' must have the ACC_FINAL modifier set but hasn't!");
}
}
if ((obj.getModifiers() & ~(ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED | ACC_STATIC | ACC_FINAL | ACC_VOLATILE | ACC_TRANSIENT)) > 0) {
addMessage("Field '"
+ tostring(obj)
+ "' has access flag(s) other than ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL, ACC_VOLATILE, ACC_TRANSIENT set (ignored).");
}
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = obj.getName();
if (!validFieldName(name)) {
throw new ClassConstraintException("Field '" + tostring(obj) + "' has illegal name '" + obj.getName() + "'.");
}
// A descriptor is often named signature in BCEL
checkIndex(obj, obj.getSignatureIndex(), CONST_Utf8);
String sig = ((ConstantUtf8) (cp.getConstant(obj.getSignatureIndex()))).getValue(); // Field or Method
// signature(=descriptor)
try {
Type.getType(sig); /* Don't need the return value */
} catch (ClassFormatError cfe) { // sometimes BCEL is a little harsh describing exceptional situations.
throw new ClassConstraintException("Illegal descriptor (==signature) '" + sig + "' used by '" + tostring(obj)
+ "'.");
}
String nameanddesc = (name + sig);
if (field_names_and_desc.contains(nameanddesc)) {
throw new ClassConstraintException("No two fields (like '" + tostring(obj)
+ "') are allowed have same names and descriptors!");
}
if (field_names.contains(name)) {
addMessage("More than one field of name '" + name
+ "' detected (but with different type descriptors). This is very unusual.");
}
field_names_and_desc.add(nameanddesc);
field_names.add(name);
Attribute[] atts = obj.getAttributes();
for (int i = 0; i < atts.length; i++) {
if ((!(atts[i] instanceof ConstantValue)) && (!(atts[i] instanceof Synthetic))
&& (!(atts[i] instanceof Deprecated))) {
addMessage("Attribute '" + tostring(atts[i]) + "' as an attribute of Field '" + tostring(obj)
+ "' is unknown and will therefore be ignored.");
}
if (!(atts[i] instanceof ConstantValue)) {
addMessage("Attribute '" + tostring(atts[i]) + "' as an attribute of Field '" + tostring(obj)
+ "' is not a ConstantValue and is therefore only of use for debuggers and such.");
}
}
}
// /////////////////////////
// METHODS (vmspec2 4.6) //
// /////////////////////////
@Override
public void visitMethod(Method obj) {
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = obj.getName();
if (!validMethodName(name, true)) {
throw new ClassConstraintException("Method '" + tostring(obj) + "' has illegal name '" + name + "'.");
}
// A descriptor is often named signature in BCEL
checkIndex(obj, obj.getSignatureIndex(), CONST_Utf8);
String sig = ((ConstantUtf8) (cp.getConstant(obj.getSignatureIndex()))).getValue(); // Method's signature(=descriptor)
Type t;
Type[] ts; // needed below the try block.
try {
t = Type.getReturnType(sig);
ts = Type.getArgumentTypes(sig);
} catch (ClassFormatError cfe) {
// Well, BCEL sometimes is a little harsh describing exceptional situations.
throw new ClassConstraintException("Illegal descriptor (==signature) '" + sig + "' used by Method '"
+ tostring(obj) + "'.");
}
// Check if referenced objects exist.
Type act = t;
if (act instanceof ArrayType)
act = ((ArrayType) act).getBasicType();
if (act instanceof ObjectType) {
Verifier v = VerifierFactory.getVerifier(((ObjectType) act).getClassName());
VerificationResult vr = v.doPass1();
if (vr != VerificationResult.VR_OK) {
throw new ClassConstraintException("Method '" + tostring(obj)
+ "' has a return type that does not pass verification pass 1: '" + vr + "'.");
}
}
for (int i = 0; i < ts.length; i++) {
act = ts[i];
if (act instanceof ArrayType)
act = ((ArrayType) act).getBasicType();
if (act instanceof ObjectType) {
Verifier v = VerifierFactory.getVerifier(((ObjectType) act).getClassName());
VerificationResult vr = v.doPass1();
if (vr != VerificationResult.VR_OK) {
throw new ClassConstraintException("Method '" + tostring(obj)
+ "' has an argument type that does not pass verification pass 1: '" + vr + "'.");
}
}
}
// Nearly forgot this! Funny return values are allowed, but a non-empty arguments list makes a different method out of
// it!
if (name.equals(STATIC_INITIALIZER_NAME) && (ts.length != 0)) {
throw new ClassConstraintException(
"Method '"
+ tostring(obj)
+ "' has illegal name '"
+ name
+ "'. It's name resembles the class or interface initialization method which it isn't because of its arguments (==descriptor).");
}
if (jc.isClass()) {
int maxone = 0;
if (obj.isPrivate())
maxone++;
if (obj.isProtected())
maxone++;
if (obj.isPublic())
maxone++;
if (maxone > 1) {
throw new ClassConstraintException("Method '" + tostring(obj)
+ "' must only have at most one of its ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC modifiers set.");
}
if (obj.isAbstract()) {
if (obj.isFinal())
throw new ClassConstraintException("Abstract method '" + tostring(obj)
+ "' must not have the ACC_FINAL modifier set.");
if (obj.isNative())
throw new ClassConstraintException("Abstract method '" + tostring(obj)
+ "' must not have the ACC_NATIVE modifier set.");
if (obj.isPrivate())
throw new ClassConstraintException("Abstract method '" + tostring(obj)
+ "' must not have the ACC_PRIVATE modifier set.");
if (obj.isStatic())
throw new ClassConstraintException("Abstract method '" + tostring(obj)
+ "' must not have the ACC_STATIC modifier set.");
if (obj.isStrictfp())
throw new ClassConstraintException("Abstract method '" + tostring(obj)
+ "' must not have the ACC_STRICT modifier set.");
if (obj.isSynchronized())
throw new ClassConstraintException("Abstract method '" + tostring(obj)
+ "' must not have the ACC_SYNCHRONIZED modifier set.");
}
} else { // isInterface!
if (!name.equals(STATIC_INITIALIZER_NAME)) {// vmspec2, p.116, 2nd paragraph
if (!obj.isPublic()) {
throw new ClassConstraintException("Interface method '" + tostring(obj)
+ "' must have the ACC_PUBLIC modifier set but hasn't!");
}
if (!obj.isAbstract()) {
throw new ClassConstraintException("Interface method '" + tostring(obj)
+ "' must have the ACC_STATIC modifier set but hasn't!");
}
if (obj.isPrivate() || obj.isProtected() || obj.isStatic() || obj.isFinal() || obj.isSynchronized()
|| obj.isNative() || obj.isStrictfp()) {
throw new ClassConstraintException(
"Interface method '"
+ tostring(obj)
+ "' must not have any of the ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL, ACC_SYNCHRONIZED, ACC_NATIVE, ACC_ABSTRACT, ACC_STRICT modifiers set.");
}
}
}
// A specific instance initialization method... (vmspec2,Page 116).
if (name.equals(CONSTRUCTOR_NAME)) {
// ..may have at most one of ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC set: is checked above.
// ..may also have ACC_STRICT set, but none of the other flags in table 4.5 (vmspec2, page 115)
if (obj.isStatic() || obj.isFinal() || obj.isSynchronized() || obj.isNative() || obj.isAbstract()) {
throw new ClassConstraintException(
"Instance initialization method '"
+ tostring(obj)
+ "' must not have any of the ACC_STATIC, ACC_FINAL, ACC_SYNCHRONIZED, ACC_NATIVE, ACC_ABSTRACT modifiers set.");
}
}
// Class and interface initialization methods...
if (name.equals(STATIC_INITIALIZER_NAME)) {
if ((obj.getModifiers() & (~ACC_STRICT)) > 0) {
addMessage("Class or interface initialization method '" + tostring(obj)
+ "' has superfluous access modifier(s) set: everything but ACC_STRICT is ignored.");
}
if (obj.isAbstract()) {
throw new ClassConstraintException(
"Class or interface initialization method '"
+ tostring(obj)
+ "' must not be abstract. This contradicts the Java Language Specification, Second Edition (which omits this constraint) but is common practice of existing verifiers.");
}
}
if ((obj.getModifiers() & ~(ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED | ACC_STATIC | ACC_FINAL | ACC_SYNCHRONIZED
| ACC_NATIVE | ACC_ABSTRACT | ACC_STRICT)) > 0) {
addMessage("Method '"
+ tostring(obj)
+ "' has access flag(s) other than ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL, ACC_SYNCHRONIZED, ACC_NATIVE, ACC_ABSTRACT, ACC_STRICT set (ignored).");
}
String nameanddesc = (name + sig);
if (method_names_and_desc.contains(nameanddesc)) {
throw new ClassConstraintException("No two methods (like '" + tostring(obj)
+ "') are allowed have same names and desciptors!");
}
method_names_and_desc.add(nameanddesc);
Attribute[] atts = obj.getAttributes();
int num_code_atts = 0;
for (int i = 0; i < atts.length; i++) {
if ((!(atts[i] instanceof Code)) && (!(atts[i] instanceof ExceptionTable)) && (!(atts[i] instanceof Synthetic))
&& (!(atts[i] instanceof Deprecated))) {
addMessage("Attribute '" + tostring(atts[i]) + "' as an attribute of Method '" + tostring(obj)
+ "' is unknown and will therefore be ignored.");
}
if ((!(atts[i] instanceof Code)) && (!(atts[i] instanceof ExceptionTable))) {
addMessage("Attribute '" + tostring(atts[i]) + "' as an attribute of Method '" + tostring(obj)
+ "' is neither Code nor Exceptions and is therefore only of use for debuggers and such.");
}
if ((atts[i] instanceof Code) && (obj.isNative() || obj.isAbstract())) {
throw new ClassConstraintException("Native or abstract methods like '" + tostring(obj)
+ "' must not have a Code attribute like '" + tostring(atts[i]) + "'."); // vmspec2 page120, 4.7.3
}
if (atts[i] instanceof Code)
num_code_atts++;
}
if (!obj.isNative() && !obj.isAbstract() && num_code_atts != 1) {
throw new ClassConstraintException("Non-native, non-abstract methods like '" + tostring(obj)
+ "' must have exactly one Code attribute (found: " + num_code_atts + ").");
}
}
// /////////////////////////////////////////////////////
// ClassFile-structure-ATTRIBUTES (vmspec2 4.1, 4.7) //
// /////////////////////////////////////////////////////
public void visitSourceFile(SourceFile obj) {// vmspec2 4.7.7
// zero or one SourceFile attr per ClassFile: see visitJavaClass()
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = ((ConstantUtf8) cp.getConstant(obj.getNameIndex())).getValue();
if (!name.equals("SourceFile")) {
throw new ClassConstraintException("The SourceFile attribute '" + tostring(obj)
+ "' is not correctly named 'SourceFile' but '" + name + "'.");
}
checkIndex(obj, obj.getSourceFileIndex(), CONST_Utf8);
String sourcefilename = ((ConstantUtf8) cp.getConstant(obj.getSourceFileIndex())).getValue(); // ==obj.getSourceFileName()
// ?
String sourcefilenamelc = sourcefilename.toLowerCase();
if ((sourcefilename.indexOf('/') != -1) || (sourcefilename.indexOf('\\') != -1) || (sourcefilename.indexOf(':') != -1)
|| (sourcefilenamelc.lastIndexOf(".java") == -1)) {
addMessage("SourceFile attribute '"
+ tostring(obj)
+ "' has a funny name: remember not to confuse certain parsers working on javap's output. Also, this name ('"
+ sourcefilename + "') is considered an unqualified (simple) file name only.");
}
}
public void visitDeprecated(Deprecated obj) {// vmspec2 4.7.10
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = ((ConstantUtf8) cp.getConstant(obj.getNameIndex())).getValue();
if (!name.equals("Deprecated")) {
throw new ClassConstraintException("The Deprecated attribute '" + tostring(obj)
+ "' is not correctly named 'Deprecated' but '" + name + "'.");
}
}
public void visitSynthetic(Synthetic obj) {// vmspec2 4.7.6
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = ((ConstantUtf8) cp.getConstant(obj.getNameIndex())).getValue();
if (!name.equals("Synthetic")) {
throw new ClassConstraintException("The Synthetic attribute '" + tostring(obj)
+ "' is not correctly named 'Synthetic' but '" + name + "'.");
}
}
public void visitInnerClasses(InnerClasses obj) {// vmspec2 4.7.5
// exactly one InnerClasses attr per ClassFile if some inner class is refernced: see visitJavaClass()
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = ((ConstantUtf8) cp.getConstant(obj.getNameIndex())).getValue();
if (!name.equals("InnerClasses")) {
throw new ClassConstraintException("The InnerClasses attribute '" + tostring(obj)
+ "' is not correctly named 'InnerClasses' but '" + name + "'.");
}
InnerClass[] ics = obj.getInnerClasses();
for (int i = 0; i < ics.length; i++) {
checkIndex(obj, ics[i].getInnerClassIndex(), CONST_Class);
int outer_idx = ics[i].getOuterClassIndex();
if (outer_idx != 0) {
checkIndex(obj, outer_idx, CONST_Class);
}
int innername_idx = ics[i].getInnerNameIndex();
if (innername_idx != 0) {
checkIndex(obj, innername_idx, CONST_Utf8);
}
int acc = ics[i].getInnerAccessFlags();
acc = acc & (~(ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED | ACC_STATIC | ACC_FINAL | ACC_INTERFACE | ACC_ABSTRACT));
if (acc != 0) {
addMessage("Unknown access flag for inner class '" + tostring(ics[i]) + "' set (InnerClasses attribute '"
+ tostring(obj) + "').");
}
}
// Semantical consistency is not yet checked by Sun, see vmspec2 4.7.5.
// [marked TODO in JustIce]
}
// //////////////////////////////////////////////////////
// field_info-structure-ATTRIBUTES (vmspec2 4.5, 4.7) //
// //////////////////////////////////////////////////////
public void visitConstantValue(ConstantValue obj) {// vmspec2 4.7.2
// Despite its name, this really is an Attribute,
// not a constant!
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = ((ConstantUtf8) cp.getConstant(obj.getNameIndex())).getValue();
if (!name.equals("ConstantValue")) {
throw new ClassConstraintException("The ConstantValue attribute '" + tostring(obj)
+ "' is not correctly named 'ConstantValue' but '" + name + "'.");
}
Object pred = carrier.predecessor();
if (pred instanceof Field) { // ConstantValue attributes are quite senseless if the predecessor is not a field.
Field f = (Field) pred;
// Field constraints have been checked before -- so we are safe using their type information.
Type field_type = Type.getType(((ConstantUtf8) (cp.getConstant(f.getSignatureIndex()))).getValue());
int index = obj.getConstantValueIndex();
if ((index < 0) || (index >= cplen)) {
throw new ClassConstraintException("Invalid index '" + index + "' used by '" + tostring(obj) + "'.");
}
Constant c = cp.getConstant(index);
if (CONST_Long.isInstance(c) && field_type.equals(Type.LONG)) {
return;
}
if (CONST_Float.isInstance(c) && field_type.equals(Type.FLOAT)) {
return;
}
if (CONST_Double.isInstance(c) && field_type.equals(Type.DOUBLE)) {
return;
}
if (CONST_Integer.isInstance(c)
&& (field_type.equals(Type.INT) || field_type.equals(Type.SHORT) || field_type.equals(Type.CHAR)
|| field_type.equals(Type.BYTE) || field_type.equals(Type.BOOLEAN))) {
return;
}
if (CONST_String.isInstance(c) && field_type.equals(Type.STRING)) {
return;
}
throw new ClassConstraintException("Illegal type of ConstantValue '" + obj + "' embedding Constant '" + c
+ "'. It is referenced by field '" + tostring(f) + "' expecting a different type: '" + field_type + "'.");
}
}
// SYNTHETIC: see above
// DEPRECATED: see above
// ///////////////////////////////////////////////////////
// method_info-structure-ATTRIBUTES (vmspec2 4.6, 4.7) //
// ///////////////////////////////////////////////////////
public void visitCode(Code obj) {// vmspec2 4.7.3
// No code attribute allowed for native or abstract methods: see visitMethod(Method).
// Code array constraints are checked in Pass3 (3a and 3b).
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = ((ConstantUtf8) cp.getConstant(obj.getNameIndex())).getValue();
if (!name.equals("Code")) {
throw new ClassConstraintException("The Code attribute '" + tostring(obj) + "' is not correctly named 'Code' but '"
+ name + "'.");
}
Method m = null; // satisfy compiler
if (!(carrier.predecessor() instanceof Method)) {
addMessage("Code attribute '" + tostring(obj) + "' is not declared in a method_info structure but in '"
+ carrier.predecessor() + "'. Ignored.");
return;
} else {
m = (Method) carrier.predecessor(); // we can assume this method was visited before;
// i.e. the data consistency was verified.
}
if (obj.getCode().length == 0) {
throw new ClassConstraintException("Code array of Code attribute '" + tostring(obj) + "' (method '" + m
+ "') must not be empty.");
}
// In JustIce, the check for correct offsets into the code array is delayed to Pass 3a.
CodeException[] exc_table = obj.getExceptionTable();
for (int i = 0; i < exc_table.length; i++) {
int exc_index = exc_table[i].getCatchType();
if (exc_index != 0) { // if 0, it catches all Throwables
checkIndex(obj, exc_index, CONST_Class);
ConstantClass cc = (ConstantClass) (cp.getConstant(exc_index));
checkIndex(cc, cc.getNameIndex(), CONST_Utf8); // cannot be sure this ConstantClass has already been visited
// (checked)!
String cname = ((ConstantUtf8) cp.getConstant(cc.getNameIndex())).getValue().replace('/', '.');
Verifier v = VerifierFactory.getVerifier(cname);
VerificationResult vr = v.doPass1();
if (vr != VerificationResult.VR_OK) {
throw new ClassConstraintException("Code attribute '" + tostring(obj) + "' (method '" + m
+ "') has an exception_table entry '" + tostring(exc_table[i]) + "' that references '" + cname
+ "' as an Exception but it does not pass verification pass 1: " + vr);
} else {
// We cannot safely trust any other "instanceof" mechanism. We need to transitively verify
// the ancestor hierarchy.
JavaClass e = Repository.lookupClass(cname);
JavaClass t = Repository.lookupClass(Type.THROWABLE.getClassName());
JavaClass o = Repository.lookupClass(Type.OBJECT.getClassName());
while (e != o) {
if (e == t)
break; // It's a subclass of Throwable, OKAY, leave.
v = VerifierFactory.getVerifier(e.getSuperclassName());
vr = v.doPass1();
if (vr != VerificationResult.VR_OK) {
throw new ClassConstraintException("Code attribute '" + tostring(obj) + "' (method '" + m
+ "') has an exception_table entry '" + tostring(exc_table[i]) + "' that references '"
+ cname + "' as an Exception but '" + e.getSuperclassName()
+ "' in the ancestor hierachy does not pass verification pass 1: " + vr);
} else {
e = Repository.lookupClass(e.getSuperclassName());
}
}
if (e != t)
throw new ClassConstraintException("Code attribute '" + tostring(obj) + "' (method '" + m
+ "') has an exception_table entry '" + tostring(exc_table[i]) + "' that references '" + cname
+ "' as an Exception but it is not a subclass of '" + t.getClassName() + "'.");
}
}
}
// Create object for local variables information
// This is highly unelegant due to usage of the Visitor pattern.
// TODO: rework it.
int method_number = -1;
Method[] ms = Repository.lookupClass(myOwner.getClassName()).getMethods();
for (int mn = 0; mn < ms.length; mn++) {
if (m == ms[mn]) {
method_number = mn;
break;
}
}
if (method_number < 0) { // Mmmmh. Can we be sure BCEL does not sometimes instantiate new objects?
throw new AssertionViolatedException(
"Could not find a known BCEL Method object in the corresponding BCEL JavaClass object.");
}
localVariablesInfos[method_number] = new LocalVariablesInfo(obj.getMaxLocals());
int num_of_lvt_attribs = 0;
// Now iterate through the attributes the Code attribute has.
Attribute[] atts = obj.getAttributes();
for (int a = 0; a < atts.length; a++) {
if ((!(atts[a] instanceof LineNumberTable)) && (!(atts[a] instanceof LocalVariableTable))) {
addMessage("Attribute '" + tostring(atts[a]) + "' as an attribute of Code attribute '" + tostring(obj)
+ "' (method '" + m + "') is unknown and will therefore be ignored.");
} else {// LineNumberTable or LocalVariableTable
addMessage("Attribute '" + tostring(atts[a]) + "' as an attribute of Code attribute '" + tostring(obj)
+ "' (method '" + m + "') will effectively be ignored and is only useful for debuggers and such.");
}
// LocalVariableTable check (partially delayed to Pass3a).
// Here because its easier to collect the information of the
// (possibly more than one) LocalVariableTables belonging to
// one certain Code attribute.
if (atts[a] instanceof LocalVariableTable) { // checks conforming to vmspec2 4.7.9
LocalVariableTable lvt = (LocalVariableTable) atts[a];
checkIndex(lvt, lvt.getNameIndex(), CONST_Utf8);
String lvtname = ((ConstantUtf8) cp.getConstant(lvt.getNameIndex())).getValue();
if (!lvtname.equals("LocalVariableTable")) {
throw new ClassConstraintException("The LocalVariableTable attribute '" + tostring(lvt)
+ "' is not correctly named 'LocalVariableTable' but '" + lvtname + "'.");
}
Code code = obj;
// In JustIce, the check for correct offsets into the code array is delayed to Pass 3a.
LocalVariable[] localvariables = lvt.getLocalVariableTable();
for (int i = 0; i < localvariables.length; i++) {
checkIndex(lvt, localvariables[i].getNameIndex(), CONST_Utf8);
String localname = ((ConstantUtf8) cp.getConstant(localvariables[i].getNameIndex())).getValue();
if (!validJavaIdentifier(localname)) {
throw new ClassConstraintException("LocalVariableTable '" + tostring(lvt)
+ "' references a local variable by the name '" + localname
+ "' which is not a legal Java simple name.");
}
checkIndex(lvt, localvariables[i].getSignatureIndex(), CONST_Utf8);
String localsig = ((ConstantUtf8) (cp.getConstant(localvariables[i].getSignatureIndex()))).getValue(); // Local
// signature(=descriptor)
Type t;
try {
t = Type.getType(localsig);
} catch (ClassFormatError cfe) { // sometimes BCEL is a little harsh describing exceptional situations.
throw new ClassConstraintException("Illegal descriptor (==signature) '" + localsig
+ "' used by LocalVariable '" + tostring(localvariables[i]) + "' referenced by '"
+ tostring(lvt) + "'.");
}
int localindex = localvariables[i].getIndex();
if (((t == Type.LONG || t == Type.DOUBLE) ? localindex + 1 : localindex) >= code.getMaxLocals()) {
throw new ClassConstraintException("LocalVariableTable attribute '" + tostring(lvt)
+ "' references a LocalVariable '" + tostring(localvariables[i])
+ "' with an index that exceeds the surrounding Code attribute's max_locals value of '"
+ code.getMaxLocals() + "'.");
}
try {
localVariablesInfos[method_number].add(localindex, localname, localvariables[i].getStartPC(),
localvariables[i].getLength(), t);
} catch (LocalVariableInfoInconsistentException lviie) {
throw new ClassConstraintException("Conflicting information in LocalVariableTable '" + tostring(lvt)
+ "' found in Code attribute '" + tostring(obj) + "' (method '" + tostring(m) + "'). "
+ lviie.getMessage());
}
}// for all local variables localvariables[i] in the LocalVariableTable attribute atts[a] END
num_of_lvt_attribs++;
if (num_of_lvt_attribs > obj.getMaxLocals()) {
throw new ClassConstraintException(
"Number of LocalVariableTable attributes of Code attribute '"
+ tostring(obj)
+ "' (method '"
+ tostring(m)
+ "') exceeds number of local variable slots '"
+ obj.getMaxLocals()
+ "' ('There may be no more than one LocalVariableTable attribute per local variable in the Code attribute.').");
}
}// if atts[a] instanceof LocalVariableTable END
}// for all attributes atts[a] END
}// visitCode(Code) END
public void visitExceptionTable(ExceptionTable obj) {// vmspec2 4.7.4
// incorrectly named, it's the Exceptions attribute (vmspec2 4.7.4)
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = ((ConstantUtf8) cp.getConstant(obj.getNameIndex())).getValue();
if (!name.equals("Exceptions")) {
throw new ClassConstraintException("The Exceptions attribute '" + tostring(obj)
+ "' is not correctly named 'Exceptions' but '" + name + "'.");
}
int[] exc_indices = obj.getExceptionIndexTable();
for (int i = 0; i < exc_indices.length; i++) {
checkIndex(obj, exc_indices[i], CONST_Class);
ConstantClass cc = (ConstantClass) (cp.getConstant(exc_indices[i]));
checkIndex(cc, cc.getNameIndex(), CONST_Utf8); // cannot be sure this ConstantClass has already been visited
// (checked)!
String cname = ((ConstantUtf8) cp.getConstant(cc.getNameIndex())).getValue().replace('/', '.'); // convert internal
// notation
// on-the-fly to
// external notation
Verifier v = VerifierFactory.getVerifier(cname);
VerificationResult vr = v.doPass1();
if (vr != VerificationResult.VR_OK) {
throw new ClassConstraintException("Exceptions attribute '" + tostring(obj) + "' references '" + cname
+ "' as an Exception but it does not pass verification pass 1: " + vr);
} else {
// We cannot safely trust any other "instanceof" mechanism. We need to transitively verify
// the ancestor hierarchy.
JavaClass e = Repository.lookupClass(cname);
JavaClass t = Repository.lookupClass(Type.THROWABLE.getClassName());
JavaClass o = Repository.lookupClass(Type.OBJECT.getClassName());
while (e != o) {
if (e == t)
break; // It's a subclass of Throwable, OKAY, leave.
v = VerifierFactory.getVerifier(e.getSuperclassName());
vr = v.doPass1();
if (vr != VerificationResult.VR_OK) {
throw new ClassConstraintException("Exceptions attribute '" + tostring(obj) + "' references '" + cname
+ "' as an Exception but '" + e.getSuperclassName()
+ "' in the ancestor hierachy does not pass verification pass 1: " + vr);
} else {
e = Repository.lookupClass(e.getSuperclassName());
}
}
if (e != t)
throw new ClassConstraintException("Exceptions attribute '" + tostring(obj) + "' references '" + cname
+ "' as an Exception but it is not a subclass of '" + t.getClassName() + "'.");
}
}
}
// SYNTHETIC: see above
// DEPRECATED: see above
// ////////////////////////////////////////////////////////////
// code_attribute-structure-ATTRIBUTES (vmspec2 4.7.3, 4.7) //
// ////////////////////////////////////////////////////////////
public void visitLineNumberTable(LineNumberTable obj) {// vmspec2 4.7.8
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
String name = ((ConstantUtf8) cp.getConstant(obj.getNameIndex())).getValue();
if (!name.equals("LineNumberTable")) {
throw new ClassConstraintException("The LineNumberTable attribute '" + tostring(obj)
+ "' is not correctly named 'LineNumberTable' but '" + name + "'.");
}
// In JustIce,this check is delayed to Pass 3a.
// LineNumber[] linenumbers = obj.getLineNumberTable();
// ...validity check...
}
public void visitLocalVariableTable(LocalVariableTable obj) {// vmspec2 4.7.9
// In JustIce,this check is partially delayed to Pass 3a.
// The other part can be found in the visitCode(Code) method.
}
// //////////////////////////////////////////////////
// MISC-structure-ATTRIBUTES (vmspec2 4.7.1, 4.7) //
// //////////////////////////////////////////////////
public void visitUnknown(Unknown obj) {// vmspec2 4.7.1
// Represents an unknown attribute.
checkIndex(obj, obj.getNameIndex(), CONST_Utf8);
// Maybe only misnamed? Give a (warning) message.
addMessage("Unknown attribute '" + tostring(obj) + "'. This attribute is not known in any context!");
}
// ////////
// BCEL //
// ////////
public void visitLocalVariable(LocalVariable obj) {
// This does not represent an Attribute but is only
// related to internal BCEL data representation.
// see visitLocalVariableTable(LocalVariableTable)
}
public void visitCodeException(CodeException obj) {
// Code constraints are checked in Pass3 (3a and 3b).
// This does not represent an Attribute but is only
// related to internal BCEL data representation.
// see visitCode(Code)
}
public void visitConstantPool(ConstantPool obj) {
// No need to. We're piggybacked by the DescendingVisitor.
// This does not represent an Attribute but is only
// related to internal BCEL data representation.
}
public void visitInnerClass(InnerClass obj) {
// This does not represent an Attribute but is only
// related to internal BCEL data representation.
}
public void visitLineNumber(LineNumber obj) {
// This does not represent an Attribute but is only
// related to internal BCEL data representation.
// see visitLineNumberTable(LineNumberTable)
}
}
/**
* Ensures that the ConstantCP-subclassed entries of the constant pool are valid. According to
* "Yellin: Low Level Security in Java", this method does not verify the existence of referenced entities (such as classes) but
* only the formal correctness (such as well-formed signatures). The visitXXX() methods throw ClassConstraintException instances
* otherwise. Precondition: index-style cross referencing in the constant pool must be valid. Simply invoke
* constant_pool_entries_satisfy_static_constraints() before.
*
* @throws ClassConstraintException otherwise.
* @see #constant_pool_entries_satisfy_static_constraints()
*/
private void field_and_method_refs_are_valid() {
JavaClass jc = Repository.lookupClass(myOwner.getClassName());
DescendingVisitor v = new DescendingVisitor(jc, new FAMRAV_Visitor(jc));
v.visit();
}
/**
* A Visitor class that ensures the ConstantCP-subclassed entries of the constant pool are valid. Precondition: index-style
* cross referencing in the constant pool must be valid.
*
* @see #constant_pool_entries_satisfy_static_constraints()
* @see org.aspectj.apache.bcel.classfile.ConstantCP
*/
private class FAMRAV_Visitor extends EmptyClassVisitor {
private final ConstantPool cp; // ==jc.getConstantPool() -- only here to save typing work.
private FAMRAV_Visitor(JavaClass _jc) {
cp = _jc.getConstantPool();
}
public void visitConstantFieldref(ConstantFieldref obj) {
if (obj.getTag() != Constants.CONSTANT_Fieldref) {
throw new ClassConstraintException("ConstantFieldref '" + tostring(obj) + "' has wrong tag!");
}
int name_and_type_index = obj.getNameAndTypeIndex();
ConstantNameAndType cnat = (ConstantNameAndType) (cp.getConstant(name_and_type_index));
String name = ((ConstantUtf8) (cp.getConstant(cnat.getNameIndex()))).getValue(); // Field or Method name
if (!validFieldName(name)) {
throw new ClassConstraintException("Invalid field name '" + name + "' referenced by '" + tostring(obj) + "'.");
}
int class_index = obj.getClassIndex();
ConstantClass cc = (ConstantClass) (cp.getConstant(class_index));
String className = ((ConstantUtf8) (cp.getConstant(cc.getNameIndex()))).getValue(); // Class Name in internal form
if (!validClassName(className)) {
throw new ClassConstraintException("Illegal class name '" + className + "' used by '" + tostring(obj) + "'.");
}
String sig = ((ConstantUtf8) (cp.getConstant(cnat.getSignatureIndex()))).getValue(); // Field or Method
// signature(=descriptor)
try {
Type.getType(sig); /* Don't need the return value */
} catch (ClassFormatError cfe) {
// Well, BCEL sometimes is a little harsh describing exceptional situations.
throw new ClassConstraintException("Illegal descriptor (==signature) '" + sig + "' used by '" + tostring(obj)
+ "'.");
}
}
public void visitConstantMethodref(ConstantMethodref obj) {
if (obj.getTag() != Constants.CONSTANT_Methodref) {
throw new ClassConstraintException("ConstantMethodref '" + tostring(obj) + "' has wrong tag!");
}
int name_and_type_index = obj.getNameAndTypeIndex();
ConstantNameAndType cnat = (ConstantNameAndType) (cp.getConstant(name_and_type_index));
String name = ((ConstantUtf8) (cp.getConstant(cnat.getNameIndex()))).getValue(); // Field or Method name
if (!validClassMethodName(name)) {
throw new ClassConstraintException("Invalid (non-interface) method name '" + name + "' referenced by '"
+ tostring(obj) + "'.");
}
int class_index = obj.getClassIndex();
ConstantClass cc = (ConstantClass) (cp.getConstant(class_index));
String className = ((ConstantUtf8) (cp.getConstant(cc.getNameIndex()))).getValue(); // Class Name in internal form
if (!validClassName(className)) {
throw new ClassConstraintException("Illegal class name '" + className + "' used by '" + tostring(obj) + "'.");
}
String sig = ((ConstantUtf8) (cp.getConstant(cnat.getSignatureIndex()))).getValue(); // Field or Method
// signature(=descriptor)
try {
Type t = Type.getReturnType(sig);
if (name.equals(CONSTRUCTOR_NAME) && (t != Type.VOID)) {
throw new ClassConstraintException("Instance initialization method must have VOID return type.");
}
} catch (ClassFormatError cfe) {
// Well, BCEL sometimes is a little harsh describing exceptional situations.
throw new ClassConstraintException("Illegal descriptor (==signature) '" + sig + "' used by '" + tostring(obj)
+ "'.");
}
}
public void visitConstantInterfaceMethodref(ConstantInterfaceMethodref obj) {
if (obj.getTag() != Constants.CONSTANT_InterfaceMethodref) {
throw new ClassConstraintException("ConstantInterfaceMethodref '" + tostring(obj) + "' has wrong tag!");
}
int name_and_type_index = obj.getNameAndTypeIndex();
ConstantNameAndType cnat = (ConstantNameAndType) (cp.getConstant(name_and_type_index));
String name = ((ConstantUtf8) (cp.getConstant(cnat.getNameIndex()))).getValue(); // Field or Method name
if (!validInterfaceMethodName(name)) {
throw new ClassConstraintException("Invalid (interface) method name '" + name + "' referenced by '" + tostring(obj)
+ "'.");
}
int class_index = obj.getClassIndex();
ConstantClass cc = (ConstantClass) (cp.getConstant(class_index));
String className = ((ConstantUtf8) (cp.getConstant(cc.getNameIndex()))).getValue(); // Class Name in internal form
if (!validClassName(className)) {
throw new ClassConstraintException("Illegal class name '" + className + "' used by '" + tostring(obj) + "'.");
}
String sig = ((ConstantUtf8) (cp.getConstant(cnat.getSignatureIndex()))).getValue(); // Field or Method
// signature(=descriptor)
try {
Type t = Type.getReturnType(sig);
if (name.equals(STATIC_INITIALIZER_NAME) && (t != Type.VOID)) {
addMessage("Class or interface initialization method '" + STATIC_INITIALIZER_NAME
+ "' usually has VOID return type instead of '" + t
+ "'. Note this is really not a requirement of The Java Virtual Machine Specification, Second Edition.");
}
} catch (ClassFormatError cfe) {
// Well, BCEL sometimes is a little harsh describing exceptional situations.
throw new ClassConstraintException("Illegal descriptor (==signature) '" + sig + "' used by '" + tostring(obj)
+ "'.");
}
}
}
/**
* This method returns true if and only if the supplied String represents a valid Java class name.
*/
private static final boolean validClassName(String name) {
/*
* TODO: implement. Are there any restrictions?
*/
return true;
}
/**
* This method returns true if and only if the supplied String represents a valid method name. This is basically the same as a
* valid identifier name in the Java programming language, but the special name for the instance initialization method is
* allowed and the special name for the class/interface initialization method may be allowed.
*/
private static boolean validMethodName(String name, boolean allowStaticInit) {
if (validJavaLangMethodName(name))
return true;
if (allowStaticInit) {
return (name.equals(CONSTRUCTOR_NAME) || name.equals(STATIC_INITIALIZER_NAME));
} else {
return name.equals(CONSTRUCTOR_NAME);
}
}
/**
* This method returns true if and only if the supplied String represents a valid method name that may be referenced by
* ConstantMethodref objects.
*/
private static boolean validClassMethodName(String name) {
return validMethodName(name, false);
}
/**
* This method returns true if and only if the supplied String represents a valid Java programming language method name stored
* as a simple (non-qualified) name. Conforming to: The Java Virtual Machine Specification, Second Edition, §2.7, §2.7.1, §2.2.
*/
private static boolean validJavaLangMethodName(String name) {
if (!Character.isJavaIdentifierStart(name.charAt(0)))
return false;
for (int i = 1; i < name.length(); i++) {
if (!Character.isJavaIdentifierPart(name.charAt(i)))
return false;
}
return true;
}
/**
* This method returns true if and only if the supplied String represents a valid Java interface method name that may be
* referenced by ConstantInterfaceMethodref objects.
*/
private static boolean validInterfaceMethodName(String name) {
// I guess we should assume special names forbidden here.
if (name.startsWith("<"))
return false;
return validJavaLangMethodName(name);
}
/**
* This method returns true if and only if the supplied String represents a valid Java identifier (so-called simple name).
*/
private static boolean validJavaIdentifier(String name) {
// vmspec2 2.7, vmspec2 2.2
if (!Character.isJavaIdentifierStart(name.charAt(0)))
return false;
for (int i = 1; i < name.length(); i++) {
if (!Character.isJavaIdentifierPart(name.charAt(i)))
return false;
}
return true;
}
/**
* This method returns true if and only if the supplied String represents a valid Java field name.
*/
private static boolean validFieldName(String name) {
// vmspec2 2.7, vmspec2 2.2
return validJavaIdentifier(name);
}
/**
* This class serves for finding out if a given JavaClass' ConstantPool references an Inner Class. The Java Virtual Machine
* Specification, Second Edition is not very precise about when an "InnerClasses" attribute has to appear. However, it states
* that there has to be exactly one InnerClasses attribute in the ClassFile structure if the constant pool of a class or
* interface refers to any class or interface "that is not a member of a package". Sun does not mean "member of the default
* package". In "Inner Classes Specification" they point out how a "bytecode name" is derived so one has to deduce what a class
* name of a class "that is not a member of a package" looks like: there is at least one character in the byte- code name that
* cannot be part of a legal Java Language Class name (and not equal to '/'). This assumption is wrong as the delimiter is '$'
* for which Character.isJavaIdentifierPart() == true. Hence, you really run into trouble if you have a toplevel class called
* "A$XXX" and another toplevel class called "A" with in inner class called "XXX". JustIce cannot repair this; please note that
* existing verifiers at this time even fail to detect missing InnerClasses attributes in pass 2.
*/
private class InnerClassDetector extends EmptyClassVisitor {
private boolean hasInnerClass = false;
private JavaClass jc;
private ConstantPool cp;
private InnerClassDetector() {
} // Don't use.
/** Constructs an InnerClassDetector working on the JavaClass _jc. */
public InnerClassDetector(JavaClass _jc) {
jc = _jc;
cp = jc.getConstantPool();
(new DescendingVisitor(jc, this)).visit();
}
/**
* Returns if the JavaClass this InnerClassDetector is working on has an Inner Class reference in its constant pool.
*/
public boolean innerClassReferenced() {
return hasInnerClass;
}
/** This method casually visits ConstantClass references. */
public void visitConstantClass(ConstantClass obj) {
Constant c = cp.getConstant(obj.getNameIndex());
if (c instanceof ConstantUtf8) { // Ignore the case where it's not a ConstantUtf8 here, we'll find out later.
String classname = ((ConstantUtf8) c).getValue();
if (classname.startsWith(jc.getClassName().replace('.', '/') + "$")) {
hasInnerClass = true;
}
}
}
}
/**
* This method is here to save typing work and improve code readability.
*/
private static String tostring(Node n) {
return new StringRepresentation(n).toString();
}
}