- package com.sun.org.apache.bcel.internal.verifier.structurals;
-
- /* ====================================================================
- * 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 java.io.*;
- import java.util.ArrayList;
- import java.util.Iterator;
- import java.util.Random;
- import java.util.Vector;
- import com.sun.org.apache.bcel.internal.Constants;
- import com.sun.org.apache.bcel.internal.Repository;
- import com.sun.org.apache.bcel.internal.classfile.*;
- import com.sun.org.apache.bcel.internal.generic.*;
- import com.sun.org.apache.bcel.internal.verifier.*;
- import com.sun.org.apache.bcel.internal.verifier.statics.*;
- import com.sun.org.apache.bcel.internal.verifier.exc.*;
-
- /**
- * This PassVerifier verifies a method of class file according to pass 3,
- * so-called structural verification 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: Pass3bVerifier.java,v 1.1.1.1 2001/10/29 20:00:42 jvanzyl Exp $
- * @author <A HREF="http://www.inf.fu-berlin.de/~ehaase"/>Enver Haase</A>
- * @see #do_verify()
- */
-
- public final class Pass3bVerifier extends PassVerifier{
- /* TODO: Throughout pass 3b, upper halves of LONG and DOUBLE
- are represented by Type.UNKNOWN. This should be changed
- in favour of LONG_Upper and DOUBLE_Upper as in pass 2. */
-
- /**
- * An InstructionContextQueue is a utility class that holds
- * (InstructionContext, ArrayList) pairs in a Queue data structure.
- * This is used to hold information about InstructionContext objects
- * externally --- i.e. that information is not saved inside the
- * InstructionContext object itself. This is useful to save the
- * execution path of the symbolic execution of the
- * Pass3bVerifier - this is not information
- * that belongs into the InstructionContext object itself.
- * Only at "execute()"ing
- * time, an InstructionContext object will get the current information
- * we have about its symbolic execution predecessors.
- */
- private static final class InstructionContextQueue{
- private Vector ics = new Vector(); // Type: InstructionContext
- private Vector ecs = new Vector(); // Type: ArrayList (of InstructionContext)
- public void add(InstructionContext ic, ArrayList executionChain){
- ics.add(ic);
- ecs.add(executionChain);
- }
- public boolean isEmpty(){
- return ics.isEmpty();
- }
- public void remove(){
- this.remove(0);
- }
- public void remove(int i){
- ics.remove(i);
- ecs.remove(i);
- }
- public InstructionContext getIC(int i){
- return (InstructionContext) ics.get(i);
- }
- public ArrayList getEC(int i){
- return (ArrayList) ecs.get(i);
- }
- public int size(){
- return ics.size();
- }
- } // end Inner Class InstructionContextQueue
-
- /** In DEBUG mode, the verification algorithm is not randomized. */
- private static final boolean DEBUG = true;
-
- /** The Verifier that created this. */
- private Verifier myOwner;
-
- /** The method number to verify. */
- private int method_no;
-
- /**
- * This class should only be instantiated by a Verifier.
- *
- * @see com.sun.org.apache.bcel.internal.verifier.Verifier
- */
- public Pass3bVerifier(Verifier owner, int method_no){
- myOwner = owner;
- this.method_no = method_no;
- }
-
- /**
- * Whenever the outgoing frame
- * situation of an InstructionContext changes, all its successors are
- * put [back] into the queue [as if they were unvisited].
- * The proof of termination is about the existence of a
- * fix point of frame merging.
- */
- private void circulationPump(ControlFlowGraph cfg, InstructionContext start, Frame vanillaFrame, InstConstraintVisitor icv, ExecutionVisitor ev){
- final Random random = new Random();
- InstructionContextQueue icq = new InstructionContextQueue();
-
- start.execute(vanillaFrame, new ArrayList(), icv, ev); // new ArrayList() <=> no Instruction was executed before
- // => Top-Level routine (no jsr call before)
- icq.add(start, new ArrayList());
-
- // LOOP!
- while (!icq.isEmpty()){
- InstructionContext u;
- ArrayList ec;
- if (!DEBUG){
- int r = random.nextInt(icq.size());
- u = icq.getIC(r);
- ec = icq.getEC(r);
- icq.remove(r);
- }
- else{
- u = icq.getIC(0);
- ec = icq.getEC(0);
- icq.remove(0);
- }
-
- ArrayList oldchain = (ArrayList) (ec.clone());
- ArrayList newchain = (ArrayList) (ec.clone());
- newchain.add(u);
-
- if ((u.getInstruction().getInstruction()) instanceof RET){
- //System.err.println(u);
- // We can only follow _one_ successor, the one after the
- // JSR that was recently executed.
- RET ret = (RET) (u.getInstruction().getInstruction());
- ReturnaddressType t = (ReturnaddressType) u.getOutFrame(oldchain).getLocals().get(ret.getIndex());
- InstructionContext theSuccessor = cfg.contextOf(t.getTarget());
-
- // Sanity check
- InstructionContext lastJSR = null;
- int skip_jsr = 0;
- for (int ss=oldchain.size()-1; ss >= 0; ss--){
- if (skip_jsr < 0){
- throw new AssertionViolatedException("More RET than JSR in execution chain?!");
- }
- //System.err.println("+"+oldchain.get(ss));
- if (((InstructionContext) oldchain.get(ss)).getInstruction().getInstruction() instanceof JsrInstruction){
- if (skip_jsr == 0){
- lastJSR = (InstructionContext) oldchain.get(ss);
- break;
- }
- else{
- skip_jsr--;
- }
- }
- if (((InstructionContext) oldchain.get(ss)).getInstruction().getInstruction() instanceof RET){
- skip_jsr++;
- }
- }
- if (lastJSR == null){
- throw new AssertionViolatedException("RET without a JSR before in ExecutionChain?! EC: '"+oldchain+"'.");
- }
- JsrInstruction jsr = (JsrInstruction) (lastJSR.getInstruction().getInstruction());
- if ( theSuccessor != (cfg.contextOf(jsr.physicalSuccessor())) ){
- throw new AssertionViolatedException("RET '"+u.getInstruction()+"' info inconsistent: jump back to '"+theSuccessor+"' or '"+cfg.contextOf(jsr.physicalSuccessor())+"'?");
- }
-
- if (theSuccessor.execute(u.getOutFrame(oldchain), newchain, icv, ev)){
- icq.add(theSuccessor, (ArrayList) newchain.clone());
- }
- }
- else{// "not a ret"
-
- // Normal successors. Add them to the queue of successors.
- InstructionContext[] succs = u.getSuccessors();
- for (int s=0; s<succs.length; s++){
- InstructionContext v = succs[s];
- if (v.execute(u.getOutFrame(oldchain), newchain, icv, ev)){
- icq.add(v, (ArrayList) newchain.clone());
- }
- }
- }// end "not a ret"
-
- // Exception Handlers. Add them to the queue of successors.
- // [subroutines are never protected; mandated by JustIce]
- ExceptionHandler[] exc_hds = u.getExceptionHandlers();
- for (int s=0; s<exc_hds.length; s++){
- InstructionContext v = cfg.contextOf(exc_hds[s].getHandlerStart());
- // TODO: the "oldchain" and "newchain" is used to determine the subroutine
- // we're in (by searching for the last JSR) by the InstructionContext
- // implementation. Therefore, we should not use this chain mechanism
- // when dealing with exception handlers.
- // Example: a JSR with an exception handler as its successor does not
- // mean we're in a subroutine if we go to the exception handler.
- // We should address this problem later; by now we simply "cut" the chain
- // by using an empty chain for the exception handlers.
- //if (v.execute(new Frame(u.getOutFrame(oldchain).getLocals(), new OperandStack (u.getOutFrame().getStack().maxStack(), (exc_hds[s].getExceptionType()==null? Type.THROWABLE : exc_hds[s].getExceptionType())) ), newchain), icv, ev){
- //icq.add(v, (ArrayList) newchain.clone());
- if (v.execute(new Frame(u.getOutFrame(oldchain).getLocals(), new OperandStack (u.getOutFrame(oldchain).getStack().maxStack(), (exc_hds[s].getExceptionType()==null? Type.THROWABLE : exc_hds[s].getExceptionType())) ), new ArrayList(), icv, ev)){
- icq.add(v, new ArrayList());
- }
- }
-
- }// while (!icq.isEmpty()) END
-
- InstructionHandle ih = start.getInstruction();
- do{
- if ((ih.getInstruction() instanceof ReturnInstruction) && (!(cfg.isDead(ih)))) {
- InstructionContext ic = cfg.contextOf(ih);
- Frame f = ic.getOutFrame(new ArrayList()); // TODO: This is buggy, we check only the top-level return instructions this way.
- LocalVariables lvs = f.getLocals();
- for (int i=0; i<lvs.maxLocals(); i++){
- if (lvs.get(i) instanceof UninitializedObjectType){
- this.addMessage("Warning: ReturnInstruction '"+ic+"' may leave method with an uninitialized object in the local variables array '"+lvs+"'.");
- }
- }
- OperandStack os = f.getStack();
- for (int i=0; i<os.size(); i++){
- if (os.peek(i) instanceof UninitializedObjectType){
- this.addMessage("Warning: ReturnInstruction '"+ic+"' may leave method with an uninitialized object on the operand stack '"+os+"'.");
- }
- }
- }
- }while ((ih = ih.getNext()) != null);
-
- }
-
- /**
- * Pass 3b implements the data flow analysis as described in the Java Virtual
- * Machine Specification, Second Edition.
- * Later versions will use LocalVariablesInfo objects to verify if the
- * verifier-inferred types and the class file's debug information (LocalVariables
- * attributes) match [TODO].
- *
- * @see com.sun.org.apache.bcel.internal.verifier.statics.LocalVariablesInfo
- * @see com.sun.org.apache.bcel.internal.verifier.statics.Pass2Verifier#getLocalVariablesInfo(int)
- */
- public VerificationResult do_verify(){
- if (! myOwner.doPass3a(method_no).equals(VerificationResult.VR_OK)){
- return VerificationResult.VR_NOTYET;
- }
-
- // Pass 3a ran before, so it's safe to assume the JavaClass object is
- // in the BCEL repository.
- JavaClass jc = Repository.lookupClass(myOwner.getClassName());
-
- ConstantPoolGen constantPoolGen = new ConstantPoolGen(jc.getConstantPool());
- // Init Visitors
- InstConstraintVisitor icv = new InstConstraintVisitor();
- icv.setConstantPoolGen(constantPoolGen);
-
- ExecutionVisitor ev = new ExecutionVisitor();
- ev.setConstantPoolGen(constantPoolGen);
-
- Method[] methods = jc.getMethods(); // Method no "method_no" exists, we ran Pass3a before on it!
-
- try{
-
- MethodGen mg = new MethodGen(methods[method_no], myOwner.getClassName(), constantPoolGen);
-
- icv.setMethodGen(mg);
-
- ////////////// DFA BEGINS HERE ////////////////
- if (! (mg.isAbstract() || mg.isNative()) ){ // IF mg HAS CODE (See pass 2)
-
- ControlFlowGraph cfg = new ControlFlowGraph(mg);
-
- // Build the initial frame situation for this method.
- Frame f = new Frame(mg.getMaxLocals(),mg.getMaxStack());
- if ( !mg.isStatic() ){
- if (mg.getName().equals(Constants.CONSTRUCTOR_NAME)){
- f._this = new UninitializedObjectType(new ObjectType(jc.getClassName()));
- f.getLocals().set(0, f._this);
- }
- else{
- f._this = null;
- f.getLocals().set(0, new ObjectType(jc.getClassName()));
- }
- }
- Type[] argtypes = mg.getArgumentTypes();
- int twoslotoffset = 0;
- for (int j=0; j<argtypes.length; j++){
- if (argtypes[j] == Type.SHORT || argtypes[j] == Type.BYTE || argtypes[j] == Type.CHAR || argtypes[j] == Type.BOOLEAN){
- argtypes[j] = Type.INT;
- }
- f.getLocals().set(twoslotoffset + j + (mg.isStatic()?0:1), argtypes[j]);
- if (argtypes[j].getSize() == 2){
- twoslotoffset++;
- f.getLocals().set(twoslotoffset + j + (mg.isStatic()?0:1), Type.UNKNOWN);
- }
- }
- circulationPump(cfg, cfg.contextOf(mg.getInstructionList().getStart()), f, icv, ev);
- }
- }
- catch (VerifierConstraintViolatedException ce){
- ce.extendMessage("Constraint violated in method '"+methods[method_no]+"':\n","");
- return new VerificationResult(VerificationResult.VERIFIED_REJECTED, ce.getMessage());
- }
- catch (RuntimeException re){
- // These are internal errors
-
- StringWriter sw = new StringWriter();
- PrintWriter pw = new PrintWriter(sw);
- re.printStackTrace(pw);
-
- throw new AssertionViolatedException("Some RuntimeException occured while verify()ing class '"+jc.getClassName()+"', method '"+methods[method_no]+"'. Original RuntimeException's stack trace:\n---\n"+sw+"---\n");
- }
- return VerificationResult.VR_OK;
- }
-
- /** Returns the method number as supplied when instantiating. */
- public int getMethodNo(){
- return method_no;
- }
- }