/*
* Copyright 2000-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.bcel.verifier.statics;
import org.apache.bcel.Constants;
import org.apache.bcel.Repository;
import org.apache.bcel.classfile.Attribute;
import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.CodeException;
import org.apache.bcel.classfile.Constant;
import org.apache.bcel.classfile.ConstantClass;
import org.apache.bcel.classfile.ConstantDouble;
import org.apache.bcel.classfile.ConstantFieldref;
import org.apache.bcel.classfile.ConstantFloat;
import org.apache.bcel.classfile.ConstantInteger;
import org.apache.bcel.classfile.ConstantInterfaceMethodref;
import org.apache.bcel.classfile.ConstantLong;
import org.apache.bcel.classfile.ConstantMethodref;
import org.apache.bcel.classfile.ConstantNameAndType;
import org.apache.bcel.classfile.ConstantString;
import org.apache.bcel.classfile.ConstantUtf8;
import org.apache.bcel.classfile.Field;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.LineNumber;
import org.apache.bcel.classfile.LineNumberTable;
import org.apache.bcel.classfile.LocalVariable;
import org.apache.bcel.classfile.LocalVariableTable;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.generic.ALOAD;
import org.apache.bcel.generic.ANEWARRAY;
import org.apache.bcel.generic.ASTORE;
import org.apache.bcel.generic.ATHROW;
import org.apache.bcel.generic.ArrayType;
import org.apache.bcel.generic.BREAKPOINT;
import org.apache.bcel.generic.CHECKCAST;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.DLOAD;
import org.apache.bcel.generic.DSTORE;
import org.apache.bcel.generic.FLOAD;
import org.apache.bcel.generic.FSTORE;
import org.apache.bcel.generic.FieldInstruction;
import org.apache.bcel.generic.GETSTATIC;
import org.apache.bcel.generic.GotoInstruction;
import org.apache.bcel.generic.IINC;
import org.apache.bcel.generic.ILOAD;
import org.apache.bcel.generic.IMPDEP1;
import org.apache.bcel.generic.IMPDEP2;
import org.apache.bcel.generic.INSTANCEOF;
import org.apache.bcel.generic.INVOKEINTERFACE;
import org.apache.bcel.generic.INVOKESPECIAL;
import org.apache.bcel.generic.INVOKESTATIC;
import org.apache.bcel.generic.INVOKEVIRTUAL;
import org.apache.bcel.generic.ISTORE;
import org.apache.bcel.generic.Instruction;
import org.apache.bcel.generic.InstructionHandle;
import org.apache.bcel.generic.InstructionList;
import org.apache.bcel.generic.InvokeInstruction;
import org.apache.bcel.generic.JsrInstruction;
import org.apache.bcel.generic.LDC;
import org.apache.bcel.generic.LDC2_W;
import org.apache.bcel.generic.LLOAD;
import org.apache.bcel.generic.LOOKUPSWITCH;
import org.apache.bcel.generic.LSTORE;
import org.apache.bcel.generic.LoadClass;
import org.apache.bcel.generic.MULTIANEWARRAY;
import org.apache.bcel.generic.NEW;
import org.apache.bcel.generic.NEWARRAY;
import org.apache.bcel.generic.ObjectType;
import org.apache.bcel.generic.PUTSTATIC;
import org.apache.bcel.generic.RET;
import org.apache.bcel.generic.ReturnInstruction;
import org.apache.bcel.generic.TABLESWITCH;
import org.apache.bcel.generic.Type;
import org.apache.bcel.verifier.PassVerifier;
import org.apache.bcel.verifier.VerificationResult;
import org.apache.bcel.verifier.Verifier;
import org.apache.bcel.verifier.VerifierFactory;
import org.apache.bcel.verifier.exc.AssertionViolatedException;
import org.apache.bcel.verifier.exc.ClassConstraintException;
import org.apache.bcel.verifier.exc.InvalidMethodException;
import org.apache.bcel.verifier.exc.StaticCodeConstraintException;
import org.apache.bcel.verifier.exc.StaticCodeInstructionConstraintException;
import org.apache.bcel.verifier.exc.StaticCodeInstructionOperandConstraintException;
/**
* This PassVerifier verifies a class file according to
* pass 3, static part 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: Pass3aVerifier.java 386056 2006-03-15 11:31:56Z tcurdt $
* @author Enver Haase
* @see #do_verify()
*/
public final class Pass3aVerifier extends PassVerifier{
/** The Verifier that created this. */
private Verifier myOwner;
/**
* The method number to verify.
* This is the index in the array returned
* by JavaClass.getMethods().
*/
private int method_no;
/** The one and only InstructionList object used by an instance of this class. It's here for performance reasons by do_verify() and its callees. */
InstructionList instructionList;
/** The one and only Code object used by an instance of this class. It's here for performance reasons by do_verify() and its callees. */
Code code;
/** Should only be instantiated by a Verifier. */
public Pass3aVerifier(Verifier owner, int method_no){
myOwner = owner;
this.method_no = method_no;
}
/**
* Pass 3a is the verification of static constraints of
* JVM code (such as legal targets of branch instructions).
* This is the part of pass 3 where you do not need data
* flow analysis.
* JustIce also delays the checks for a correct exception
* table of a Code attribute and correct line number entries
* in a LineNumberTable attribute of a Code attribute (which
* conceptually belong to pass 2) to this pass. Also, most
* of the check for valid local variable entries in a
* LocalVariableTable attribute of a Code attribute is
* delayed until this pass.
* All these checks need access to the code array of the
* Code attribute.
*
* @throws InvalidMethodException if the method to verify does not exist.
*/
public VerificationResult do_verify(){
try {
if (myOwner.doPass2().equals(VerificationResult.VR_OK)){
// Okay, class file was loaded correctly by Pass 1
// and satisfies static constraints of Pass 2.
JavaClass jc = Repository.lookupClass(myOwner.getClassName());
Method[] methods = jc.getMethods();
if (method_no >= methods.length){
throw new InvalidMethodException("METHOD DOES NOT EXIST!");
}
Method method = methods[method_no];
code = method.getCode();
// No Code? Nothing to verify!
if ( method.isAbstract() || method.isNative() ){ // IF mg HAS NO CODE (static constraint of Pass 2)
return VerificationResult.VR_OK;
}
// TODO:
// We want a very sophisticated code examination here with good explanations
// on where to look for an illegal instruction or such.
// Only after that we should try to build an InstructionList and throw an
// AssertionViolatedException if after our examination InstructionList building
// still fails.
// That examination should be implemented in a byte-oriented way, i.e. look for
// an instruction, make sure its validity, count its length, find the next
// instruction and so on.
try{
instructionList = new InstructionList(method.getCode().getCode());
}
catch(RuntimeException re){
return new VerificationResult(VerificationResult.VERIFIED_REJECTED, "Bad bytecode in the code array of the Code attribute of method '"+method+"'.");
}
instructionList.setPositions(true);
// Start verification.
VerificationResult vr = VerificationResult.VR_OK; //default
try{
delayedPass2Checks();
}
catch(ClassConstraintException cce){
vr = new VerificationResult(VerificationResult.VERIFIED_REJECTED, cce.getMessage());
return vr;
}
try{
pass3StaticInstructionChecks();
pass3StaticInstructionOperandsChecks();
}
catch(StaticCodeConstraintException scce){
vr = new VerificationResult(VerificationResult.VERIFIED_REJECTED, scce.getMessage());
}
catch(ClassCastException cce){
vr = new VerificationResult(VerificationResult.VERIFIED_REJECTED, "Class Cast Exception: " + cce.getMessage());
}
return vr;
}
else{ //did not pass Pass 2.
return VerificationResult.VR_NOTYET;
}
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
/**
* These are the checks that could be done in pass 2 but are delayed to pass 3
* for performance reasons. Also, these checks need access to the code array
* of the Code attribute of a Method so it's okay to perform them here.
* Also see the description of the do_verify() method.
*
* @throws ClassConstraintException if the verification fails.
* @see #do_verify()
*/
private void delayedPass2Checks(){
int[] instructionPositions = instructionList.getInstructionPositions();
int codeLength = code.getCode().length;
/////////////////////
// LineNumberTable //
/////////////////////
LineNumberTable lnt = code.getLineNumberTable();
if (lnt != null){
LineNumber[] lineNumbers = lnt.getLineNumberTable();
IntList offsets = new IntList();
lineNumber_loop: for (int i=0; i < lineNumbers.length; i++){ // may appear in any order.
for (int j=0; j < instructionPositions.length; j++){
// TODO: Make this a binary search! The instructionPositions array is naturally ordered!
int offset = lineNumbers[i].getStartPC();
if (instructionPositions[j] == offset){
if (offsets.contains(offset)){
addMessage("LineNumberTable attribute '"+code.getLineNumberTable()+"' refers to the same code offset ('"+offset+"') more than once which is violating the semantics [but is sometimes produced by IBM's 'jikes' compiler].");
}
else{
offsets.add(offset);
}
continue lineNumber_loop;
}
}
throw new ClassConstraintException("Code attribute '"+code+"' has a LineNumberTable attribute '"+code.getLineNumberTable()+"' referring to a code offset ('"+lineNumbers[i].getStartPC()+"') that does not exist.");
}
}
///////////////////////////
// LocalVariableTable(s) //
///////////////////////////
/* We cannot use code.getLocalVariableTable() because there could be more
than only one. This is a bug in BCEL. */
Attribute[] atts = code.getAttributes();
for (int a=0; a<atts.length; a++){
if (atts[a] instanceof LocalVariableTable){
LocalVariableTable lvt = (LocalVariableTable) atts[a];
if (lvt != null){
LocalVariable[] localVariables = lvt.getLocalVariableTable();
for (int i=0; i<localVariables.length; i++){
int startpc = localVariables[i].getStartPC();
int length = localVariables[i].getLength();
if (!contains(instructionPositions, startpc)){
throw new ClassConstraintException("Code attribute '"+code+"' has a LocalVariableTable attribute '"+code.getLocalVariableTable()+"' referring to a code offset ('"+startpc+"') that does not exist.");
}
if ( (!contains(instructionPositions, startpc+length)) && (startpc+length != codeLength) ){
throw new ClassConstraintException("Code attribute '"+code+"' has a LocalVariableTable attribute '"+code.getLocalVariableTable()+"' referring to a code offset start_pc+length ('"+(startpc+length)+"') that does not exist.");
}
}
}
}
}
////////////////////
// ExceptionTable //
////////////////////
// In BCEL's "classfile" API, the startPC/endPC-notation is
// inclusive/exclusive as in the Java Virtual Machine Specification.
// WARNING: This is not true for BCEL's "generic" API.
CodeException[] exceptionTable = code.getExceptionTable();
for (int i=0; i<exceptionTable.length; i++){
int startpc = exceptionTable[i].getStartPC();
int endpc = exceptionTable[i].getEndPC();
int handlerpc = exceptionTable[i].getHandlerPC();
if (startpc >= endpc){
throw new ClassConstraintException("Code attribute '"+code+"' has an exception_table entry '"+exceptionTable[i]+"' that has its start_pc ('"+startpc+"') not smaller than its end_pc ('"+endpc+"').");
}
if (!contains(instructionPositions, startpc)){
throw new ClassConstraintException("Code attribute '"+code+"' has an exception_table entry '"+exceptionTable[i]+"' that has a non-existant bytecode offset as its start_pc ('"+startpc+"').");
}
if ( (!contains(instructionPositions, endpc)) && (endpc != codeLength)){
throw new ClassConstraintException("Code attribute '"+code+"' has an exception_table entry '"+exceptionTable[i]+"' that has a non-existant bytecode offset as its end_pc ('"+startpc+"') [that is also not equal to code_length ('"+codeLength+"')].");
}
if (!contains(instructionPositions, handlerpc)){
throw new ClassConstraintException("Code attribute '"+code+"' has an exception_table entry '"+exceptionTable[i]+"' that has a non-existant bytecode offset as its handler_pc ('"+handlerpc+"').");
}
}
}
/**
* These are the checks if constraints are satisfied which are described in the
* Java Virtual Machine Specification, Second Edition as Static Constraints on
* the instructions of Java Virtual Machine Code (chapter 4.8.1).
*
* @throws StaticCodeConstraintException if the verification fails.
*/
private void pass3StaticInstructionChecks(){
// Code array must not be empty:
// Enforced in pass 2 (also stated in the static constraints of the Code
// array in vmspec2), together with pass 1 (reading code_length bytes and
// interpreting them as code[]). So this must not be checked again here.
if (! (code.getCode().length < 65536)){// contradicts vmspec2 page 152 ("Limitations"), but is on page 134.
throw new StaticCodeInstructionConstraintException("Code array in code attribute '"+code+"' too big: must be smaller than 65536 bytes.");
}
// First opcode at offset 0: okay, that's clear. Nothing to do.
// Only instances of the instructions documented in Section 6.4 may appear in
// the code array.
// For BCEL's sake, we cannot handle WIDE stuff, but hopefully BCEL does its job right :)
// The last byte of the last instruction in the code array must be the byte at index
// code_length-1 : See the do_verify() comments. We actually don't iterate through the
// byte array, but use an InstructionList so we cannot check for this. But BCEL does
// things right, so it's implicitly okay.
// TODO: Check how BCEL handles (and will handle) instructions like IMPDEP1, IMPDEP2,
// BREAKPOINT... that BCEL knows about but which are illegal anyway.
// We currently go the safe way here.
InstructionHandle ih = instructionList.getStart();
while (ih != null){
Instruction i = ih.getInstruction();
if (i instanceof IMPDEP1){
throw new StaticCodeInstructionConstraintException("IMPDEP1 must not be in the code, it is an illegal instruction for _internal_ JVM use!");
}
if (i instanceof IMPDEP2){
throw new StaticCodeInstructionConstraintException("IMPDEP2 must not be in the code, it is an illegal instruction for _internal_ JVM use!");
}
if (i instanceof BREAKPOINT){
throw new StaticCodeInstructionConstraintException("BREAKPOINT must not be in the code, it is an illegal instruction for _internal_ JVM use!");
}
ih = ih.getNext();
}
// The original verifier seems to do this check here, too.
// An unreachable last instruction may also not fall through the
// end of the code, which is stupid -- but with the original
// verifier's subroutine semantics one cannot predict reachability.
Instruction last = instructionList.getEnd().getInstruction();
if (! ((last instanceof ReturnInstruction) ||
(last instanceof RET) ||
(last instanceof GotoInstruction) ||
(last instanceof ATHROW) )) {
throw new StaticCodeInstructionConstraintException("Execution must not fall off the bottom of the code array. This constraint is enforced statically as some existing verifiers do - so it may be a false alarm if the last instruction is not reachable.");
}
}
/**
* These are the checks for the satisfaction of constraints which are described in the
* Java Virtual Machine Specification, Second Edition as Static Constraints on
* the operands of instructions of Java Virtual Machine Code (chapter 4.8.1).
* BCEL parses the code array to create an InstructionList and therefore has to check
* some of these constraints. Additional checks are also implemented here.
*
* @throws StaticCodeConstraintException if the verification fails.
*/
private void pass3StaticInstructionOperandsChecks(){
try {
// When building up the InstructionList, BCEL has already done all those checks
// mentioned in The Java Virtual Machine Specification, Second Edition, as
// "static constraints on the operands of instructions in the code array".
// TODO: see the do_verify() comments. Maybe we should really work on the
// byte array first to give more comprehensive messages.
// TODO: Review Exception API, possibly build in some "offending instruction" thing
// when we're ready to insulate the offending instruction by doing the
// above thing.
// TODO: Implement as much as possible here. BCEL does _not_ check everything.
ConstantPoolGen cpg = new ConstantPoolGen(Repository.lookupClass(myOwner.getClassName()).getConstantPool());
InstOperandConstraintVisitor v = new InstOperandConstraintVisitor(cpg);
// Checks for the things BCEL does _not_ handle itself.
InstructionHandle ih = instructionList.getStart();
while (ih != null){
Instruction i = ih.getInstruction();
// An "own" constraint, due to JustIce's new definition of what "subroutine" means.
if (i instanceof JsrInstruction){
InstructionHandle target = ((JsrInstruction) i).getTarget();
if (target == instructionList.getStart()){
throw new StaticCodeInstructionOperandConstraintException("Due to JustIce's clear definition of subroutines, no JSR or JSR_W may have a top-level instruction (such as the very first instruction, which is targeted by instruction '"+ih+"' as its target.");
}
if (!(target.getInstruction() instanceof ASTORE)){
throw new StaticCodeInstructionOperandConstraintException("Due to JustIce's clear definition of subroutines, no JSR or JSR_W may target anything else than an ASTORE instruction. Instruction '"+ih+"' targets '"+target+"'.");
}
}
// vmspec2, page 134-137
ih.accept(v);
ih = ih.getNext();
}
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
/** A small utility method returning if a given int i is in the given int[] ints. */
private static boolean contains(int[] ints, int i){
for (int j=0; j<ints.length; j++){
if (ints[j]==i) {
return true;
}
}
return false;
}
/** Returns the method number as supplied when instantiating. */
public int getMethodNo(){
return method_no;
}
/**
* This visitor class does the actual checking for the instruction
* operand's constraints.
*/
private class InstOperandConstraintVisitor extends org.apache.bcel.generic.EmptyVisitor{
/** The ConstantPoolGen instance this Visitor operates on. */
private ConstantPoolGen cpg;
/** The only Constructor. */
InstOperandConstraintVisitor(ConstantPoolGen cpg){
this.cpg = cpg;
}
/**
* Utility method to return the max_locals value of the method verified
* by the surrounding Pass3aVerifier instance.
*/
private int max_locals(){
try {
return Repository.lookupClass(myOwner.getClassName()).getMethods()[method_no].getCode().getMaxLocals();
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
/**
* A utility method to always raise an exeption.
*/
private void constraintViolated(Instruction i, String message) {
throw new StaticCodeInstructionOperandConstraintException("Instruction "+i+" constraint violated: "+message);
}
/**
* A utility method to raise an exception if the index is not
* a valid constant pool index.
*/
private void indexValid(Instruction i, int idx){
if (idx < 0 || idx >= cpg.getSize()){
constraintViolated(i, "Illegal constant pool index '"+idx+"'.");
}
}
///////////////////////////////////////////////////////////
// The Java Virtual Machine Specification, pages 134-137 //
///////////////////////////////////////////////////////////
/**
* Assures the generic preconditions of a LoadClass instance.
* The referenced class is loaded and pass2-verified.
*/
public void visitLoadClass(LoadClass o){
ObjectType t = o.getLoadClassType(cpg);
if (t != null){// null means "no class is loaded"
Verifier v = VerifierFactory.getVerifier(t.getClassName());
VerificationResult vr = v.doPass1();
if (vr.getStatus() != VerificationResult.VERIFIED_OK){
constraintViolated((Instruction) o, "Class '"+o.getLoadClassType(cpg).getClassName()+"' is referenced, but cannot be loaded: '"+vr+"'.");
}
}
}
// The target of each jump and branch instruction [...] must be the opcode [...]
// BCEL _DOES_ handle this.
// tableswitch: BCEL will do it, supposedly.
// lookupswitch: BCEL will do it, supposedly.
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
// LDC and LDC_W (LDC_W is a subclass of LDC in BCEL's model)
public void visitLDC(LDC o){
indexValid(o, o.getIndex());
Constant c = cpg.getConstant(o.getIndex());
if (c instanceof ConstantClass){
addMessage("Operand of LDC or LDC_W is CONSTANT_Class '"+c+"' - this is only supported in JDK 1.5 and higher.");
}
else{
if (! ( (c instanceof ConstantInteger) ||
(c instanceof ConstantFloat) ||
(c instanceof ConstantString) ) ){
constraintViolated(o, "Operand of LDC or LDC_W must be one of CONSTANT_Integer, CONSTANT_Float or CONSTANT_String, but is '"+c+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
// LDC2_W
public void visitLDC2_W(LDC2_W o){
indexValid(o, o.getIndex());
Constant c = cpg.getConstant(o.getIndex());
if (! ( (c instanceof ConstantLong) ||
(c instanceof ConstantDouble) ) ){
constraintViolated(o, "Operand of LDC2_W must be CONSTANT_Long or CONSTANT_Double, but is '"+c+"'.");
}
try{
indexValid(o, o.getIndex()+1);
}
catch(StaticCodeInstructionOperandConstraintException e){
throw new AssertionViolatedException("OOPS: Does not BCEL handle that? LDC2_W operand has a problem.");
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
//getfield, putfield, getstatic, putstatic
public void visitFieldInstruction(FieldInstruction o){
try {
indexValid(o, o.getIndex());
Constant c = cpg.getConstant(o.getIndex());
if (! (c instanceof ConstantFieldref)){
constraintViolated(o, "Indexing a constant that's not a CONSTANT_Fieldref but a '"+c+"'.");
}
String field_name = o.getFieldName(cpg);
JavaClass jc = Repository.lookupClass(o.getClassType(cpg).getClassName());
Field[] fields = jc.getFields();
Field f = null;
for (int i=0; i<fields.length; i++){
if (fields[i].getName().equals(field_name)){
Type f_type = Type.getType(fields[i].getSignature());
Type o_type = o.getType(cpg);
/* TODO: Check if assignment compatibility is sufficient.
* What does Sun do?
*/
if (f_type.equals(o_type)){
f = fields[i];
break;
}
}
}
if (f == null){
JavaClass[] superclasses = jc.getSuperClasses();
outer:
for (int j=0; j<superclasses.length; j++){
fields = superclasses[j].getFields();
for (int i=0; i<fields.length; i++){
if (fields[i].getName().equals(field_name)){
Type f_type = Type.getType(fields[i].getSignature());
Type o_type = o.getType(cpg);
if (f_type.equals(o_type)){
f = fields[i];
if ((f.getAccessFlags() & (Constants.ACC_PUBLIC | Constants.ACC_PROTECTED)) == 0) {
f = null;
}
break outer;
}
}
}
}
if (f == null) {
constraintViolated(o, "Referenced field '"+field_name+"' does not exist in class '"+jc.getClassName()+"'.");
}
}
else{
/* TODO: Check if assignment compatibility is sufficient.
What does Sun do? */
Type f_type = Type.getType(f.getSignature());
Type o_type = o.getType(cpg);
// Argh. Sun's implementation allows us to have multiple fields of
// the same name but with a different signature.
//if (! f_type.equals(o_type)){
// constraintViolated(o, "Referenced field '"+field_name+"' has type '"+f_type+"' instead of '"+o_type+"' as expected.");
//}
/* TODO: Check for access modifiers here. */
}
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitInvokeInstruction(InvokeInstruction o){
indexValid(o, o.getIndex());
if ( (o instanceof INVOKEVIRTUAL) ||
(o instanceof INVOKESPECIAL) ||
(o instanceof INVOKESTATIC) ){
Constant c = cpg.getConstant(o.getIndex());
if (! (c instanceof ConstantMethodref)){
constraintViolated(o, "Indexing a constant that's not a CONSTANT_Methodref but a '"+c+"'.");
}
else{
// Constants are okay due to pass2.
ConstantNameAndType cnat = (ConstantNameAndType) (cpg.getConstant(((ConstantMethodref) c).getNameAndTypeIndex()));
ConstantUtf8 cutf8 = (ConstantUtf8) (cpg.getConstant(cnat.getNameIndex()));
if (cutf8.getBytes().equals(Constants.CONSTRUCTOR_NAME) && (!(o instanceof INVOKESPECIAL)) ){
constraintViolated(o, "Only INVOKESPECIAL is allowed to invoke instance initialization methods.");
}
if ( (! (cutf8.getBytes().equals(Constants.CONSTRUCTOR_NAME)) ) && (cutf8.getBytes().startsWith("<")) ){
constraintViolated(o, "No method with a name beginning with '<' other than the instance initialization methods may be called by the method invocation instructions.");
}
}
}
else{ //if (o instanceof INVOKEINTERFACE){
Constant c = cpg.getConstant(o.getIndex());
if (! (c instanceof ConstantInterfaceMethodref)){
constraintViolated(o, "Indexing a constant that's not a CONSTANT_InterfaceMethodref but a '"+c+"'.");
}
// TODO: From time to time check if BCEL allows to detect if the
// 'count' operand is consistent with the information in the
// CONSTANT_InterfaceMethodref and if the last operand is zero.
// By now, BCEL hides those two operands because they're superfluous.
// Invoked method must not be <init> or <clinit>
ConstantNameAndType cnat = (ConstantNameAndType) (cpg.getConstant(((ConstantInterfaceMethodref)c).getNameAndTypeIndex()));
String name = ((ConstantUtf8) (cpg.getConstant(cnat.getNameIndex()))).getBytes();
if (name.equals(Constants.CONSTRUCTOR_NAME)){
constraintViolated(o, "Method to invoke must not be '"+Constants.CONSTRUCTOR_NAME+"'.");
}
if (name.equals(Constants.STATIC_INITIALIZER_NAME)){
constraintViolated(o, "Method to invoke must not be '"+Constants.STATIC_INITIALIZER_NAME+"'.");
}
}
// The LoadClassType is the method-declaring class, so we have to check the other types.
Type t = o.getReturnType(cpg);
if (t instanceof ArrayType){
t = ((ArrayType) t).getBasicType();
}
if (t instanceof ObjectType){
Verifier v = VerifierFactory.getVerifier(((ObjectType) t).getClassName());
VerificationResult vr = v.doPass2();
if (vr.getStatus() != VerificationResult.VERIFIED_OK){
constraintViolated(o, "Return type class/interface could not be verified successfully: '"+vr.getMessage()+"'.");
}
}
Type[] ts = o.getArgumentTypes(cpg);
for (int i=0; i<ts.length; i++){
t = ts[i];
if (t instanceof ArrayType){
t = ((ArrayType) t).getBasicType();
}
if (t instanceof ObjectType){
Verifier v = VerifierFactory.getVerifier(((ObjectType) t).getClassName());
VerificationResult vr = v.doPass2();
if (vr.getStatus() != VerificationResult.VERIFIED_OK){
constraintViolated(o, "Argument type class/interface could not be verified successfully: '"+vr.getMessage()+"'.");
}
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitINSTANCEOF(INSTANCEOF o){
indexValid(o, o.getIndex());
Constant c = cpg.getConstant(o.getIndex());
if (! (c instanceof ConstantClass)){
constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitCHECKCAST(CHECKCAST o){
indexValid(o, o.getIndex());
Constant c = cpg.getConstant(o.getIndex());
if (! (c instanceof ConstantClass)){
constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitNEW(NEW o){
indexValid(o, o.getIndex());
Constant c = cpg.getConstant(o.getIndex());
if (! (c instanceof ConstantClass)){
constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
}
else{
ConstantUtf8 cutf8 = (ConstantUtf8) (cpg.getConstant( ((ConstantClass) c).getNameIndex() ));
Type t = Type.getType("L"+cutf8.getBytes()+";");
if (t instanceof ArrayType){
constraintViolated(o, "NEW must not be used to create an array.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitMULTIANEWARRAY(MULTIANEWARRAY o){
indexValid(o, o.getIndex());
Constant c = cpg.getConstant(o.getIndex());
if (! (c instanceof ConstantClass)){
constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
}
int dimensions2create = o.getDimensions();
if (dimensions2create < 1){
constraintViolated(o, "Number of dimensions to create must be greater than zero.");
}
Type t = o.getType(cpg);
if (t instanceof ArrayType){
int dimensions = ((ArrayType) t).getDimensions();
if (dimensions < dimensions2create){
constraintViolated(o, "Not allowed to create array with more dimensions ('+dimensions2create+') than the one referenced by the CONSTANT_Class '"+t+"'.");
}
}
else{
constraintViolated(o, "Expecting a CONSTANT_Class referencing an array type. [Constraint not found in The Java Virtual Machine Specification, Second Edition, 4.8.1]");
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitANEWARRAY(ANEWARRAY o){
indexValid(o, o.getIndex());
Constant c = cpg.getConstant(o.getIndex());
if (! (c instanceof ConstantClass)){
constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
}
Type t = o.getType(cpg);
if (t instanceof ArrayType){
int dimensions = ((ArrayType) t).getDimensions();
if (dimensions >= 255){
constraintViolated(o, "Not allowed to create an array with more than 255 dimensions.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitNEWARRAY(NEWARRAY o){
byte t = o.getTypecode();
if (! ( (t == Constants.T_BOOLEAN) ||
(t == Constants.T_CHAR) ||
(t == Constants.T_FLOAT) ||
(t == Constants.T_DOUBLE) ||
(t == Constants.T_BYTE) ||
(t == Constants.T_SHORT) ||
(t == Constants.T_INT) ||
(t == Constants.T_LONG) ) ){
constraintViolated(o, "Illegal type code '+t+' for 'atype' operand.");
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitILOAD(ILOAD o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative.");
}
else{
int maxminus1 = max_locals()-1;
if (idx > maxminus1){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-1 '"+maxminus1+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitFLOAD(FLOAD o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative.");
}
else{
int maxminus1 = max_locals()-1;
if (idx > maxminus1){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-1 '"+maxminus1+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitALOAD(ALOAD o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative.");
}
else{
int maxminus1 = max_locals()-1;
if (idx > maxminus1){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-1 '"+maxminus1+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitISTORE(ISTORE o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative.");
}
else{
int maxminus1 = max_locals()-1;
if (idx > maxminus1){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-1 '"+maxminus1+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitFSTORE(FSTORE o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative.");
}
else{
int maxminus1 = max_locals()-1;
if (idx > maxminus1){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-1 '"+maxminus1+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitASTORE(ASTORE o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative.");
}
else{
int maxminus1 = max_locals()-1;
if (idx > maxminus1){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-1 '"+maxminus1+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitIINC(IINC o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative.");
}
else{
int maxminus1 = max_locals()-1;
if (idx > maxminus1){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-1 '"+maxminus1+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitRET(RET o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative.");
}
else{
int maxminus1 = max_locals()-1;
if (idx > maxminus1){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-1 '"+maxminus1+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitLLOAD(LLOAD o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative. [Constraint by JustIce as an analogon to the single-slot xLOAD/xSTORE instructions; may not happen anyway.]");
}
else{
int maxminus2 = max_locals()-2;
if (idx > maxminus2){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-2 '"+maxminus2+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitDLOAD(DLOAD o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative. [Constraint by JustIce as an analogon to the single-slot xLOAD/xSTORE instructions; may not happen anyway.]");
}
else{
int maxminus2 = max_locals()-2;
if (idx > maxminus2){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-2 '"+maxminus2+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitLSTORE(LSTORE o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative. [Constraint by JustIce as an analogon to the single-slot xLOAD/xSTORE instructions; may not happen anyway.]");
}
else{
int maxminus2 = max_locals()-2;
if (idx > maxminus2){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-2 '"+maxminus2+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitDSTORE(DSTORE o){
int idx = o.getIndex();
if (idx < 0){
constraintViolated(o, "Index '"+idx+"' must be non-negative. [Constraint by JustIce as an analogon to the single-slot xLOAD/xSTORE instructions; may not happen anyway.]");
}
else{
int maxminus2 = max_locals()-2;
if (idx > maxminus2){
constraintViolated(o, "Index '"+idx+"' must not be greater than max_locals-2 '"+maxminus2+"'.");
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitLOOKUPSWITCH(LOOKUPSWITCH o){
int[] matchs = o.getMatchs();
int max = Integer.MIN_VALUE;
for (int i=0; i<matchs.length; i++){
if (matchs[i] == max && i != 0){
constraintViolated(o, "Match '"+matchs[i]+"' occurs more than once.");
}
if (matchs[i] < max){
constraintViolated(o, "Lookup table must be sorted but isn't.");
}
else{
max = matchs[i];
}
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitTABLESWITCH(TABLESWITCH o){
// "high" must be >= "low". We cannot check this, as BCEL hides
// it from us.
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitPUTSTATIC(PUTSTATIC o){
try {
String field_name = o.getFieldName(cpg);
JavaClass jc = Repository.lookupClass(o.getClassType(cpg).getClassName());
Field[] fields = jc.getFields();
Field f = null;
for (int i=0; i<fields.length; i++){
if (fields[i].getName().equals(field_name)){
f = fields[i];
break;
}
}
if (f == null){
throw new AssertionViolatedException("Field not found?!?");
}
if (f.isFinal()){
if (!(myOwner.getClassName().equals(o.getClassType(cpg).getClassName()))){
constraintViolated(o, "Referenced field '"+f+"' is final and must therefore be declared in the current class '"+myOwner.getClassName()+"' which is not the case: it is declared in '"+o.getClassType(cpg).getClassName()+"'.");
}
}
if (! (f.isStatic())){
constraintViolated(o, "Referenced field '"+f+"' is not static which it should be.");
}
String meth_name = Repository.lookupClass(myOwner.getClassName()).getMethods()[method_no].getName();
// If it's an interface, it can be set only in <clinit>.
if ((!(jc.isClass())) && (!(meth_name.equals(Constants.STATIC_INITIALIZER_NAME)))){
constraintViolated(o, "Interface field '"+f+"' must be set in a '"+Constants.STATIC_INITIALIZER_NAME+"' method.");
}
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitGETSTATIC(GETSTATIC o){
try {
String field_name = o.getFieldName(cpg);
JavaClass jc = Repository.lookupClass(o.getClassType(cpg).getClassName());
Field[] fields = jc.getFields();
Field f = null;
for (int i=0; i<fields.length; i++){
if (fields[i].getName().equals(field_name)){
f = fields[i];
break;
}
}
if (f == null){
throw new AssertionViolatedException("Field not found?!?");
}
if (! (f.isStatic())){
constraintViolated(o, "Referenced field '"+f+"' is not static which it should be.");
}
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
/* Checks if the constraints of operands of the said instruction(s) are satisfied. */
//public void visitPUTFIELD(PUTFIELD o){
// for performance reasons done in Pass 3b
//}
/* Checks if the constraints of operands of the said instruction(s) are satisfied. */
//public void visitGETFIELD(GETFIELD o){
// for performance reasons done in Pass 3b
//}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitINVOKEINTERFACE(INVOKEINTERFACE o){
try {
// INVOKEINTERFACE is a LoadClass; the Class where the referenced method is declared in,
// is therefore resolved/verified.
// INVOKEINTERFACE is an InvokeInstruction, the argument and return types are resolved/verified,
// too. So are the allowed method names.
String classname = o.getClassName(cpg);
JavaClass jc = Repository.lookupClass(classname);
Method[] ms = jc.getMethods();
Method m = null;
for (int i=0; i<ms.length; i++){
if ( (ms[i].getName().equals(o.getMethodName(cpg))) &&
(Type.getReturnType(ms[i].getSignature()).equals(o.getReturnType(cpg))) &&
(objarrayequals(Type.getArgumentTypes(ms[i].getSignature()), o.getArgumentTypes(cpg))) ){
m = ms[i];
break;
}
}
if (m == null){
constraintViolated(o, "Referenced method '"+o.getMethodName(cpg)+"' with expected signature '"+o.getSignature(cpg)+"' not found in class '"+jc.getClassName()+"'. The native verifier does allow the method to be declared in some superinterface, which the Java Virtual Machine Specification, Second Edition does not.");
}
if (jc.isClass()){
constraintViolated(o, "Referenced class '"+jc.getClassName()+"' is a class, but not an interface as expected.");
}
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitINVOKESPECIAL(INVOKESPECIAL o){
try {
// INVOKESPECIAL is a LoadClass; the Class where the referenced method is declared in,
// is therefore resolved/verified.
// INVOKESPECIAL is an InvokeInstruction, the argument and return types are resolved/verified,
// too. So are the allowed method names.
String classname = o.getClassName(cpg);
JavaClass jc = Repository.lookupClass(classname);
Method[] ms = jc.getMethods();
Method m = null;
for (int i=0; i<ms.length; i++){
if ( (ms[i].getName().equals(o.getMethodName(cpg))) &&
(Type.getReturnType(ms[i].getSignature()).equals(o.getReturnType(cpg))) &&
(objarrayequals(Type.getArgumentTypes(ms[i].getSignature()), o.getArgumentTypes(cpg))) ){
m = ms[i];
break;
}
}
if (m == null){
constraintViolated(o, "Referenced method '"+o.getMethodName(cpg)+"' with expected signature '"+o.getSignature(cpg)+"' not found in class '"+jc.getClassName()+"'. The native verifier does allow the method to be declared in some superclass or implemented interface, which the Java Virtual Machine Specification, Second Edition does not.");
}
JavaClass current = Repository.lookupClass(myOwner.getClassName());
if (current.isSuper()){
if ((Repository.instanceOf( current, jc )) && (!current.equals(jc))){
if (! (o.getMethodName(cpg).equals(Constants.CONSTRUCTOR_NAME) )){
// Special lookup procedure for ACC_SUPER classes.
int supidx = -1;
Method meth = null;
while (supidx != 0){
supidx = current.getSuperclassNameIndex();
current = Repository.lookupClass(current.getSuperclassName());
Method[] meths = current.getMethods();
for (int i=0; i<meths.length; i++){
if ( (meths[i].getName().equals(o.getMethodName(cpg))) &&
(Type.getReturnType(meths[i].getSignature()).equals(o.getReturnType(cpg))) &&
(objarrayequals(Type.getArgumentTypes(meths[i].getSignature()), o.getArgumentTypes(cpg))) ){
meth = meths[i];
break;
}
}
if (meth != null) {
break;
}
}
if (meth == null){
constraintViolated(o, "ACC_SUPER special lookup procedure not successful: method '"+o.getMethodName(cpg)+"' with proper signature not declared in superclass hierarchy.");
}
}
}
}
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitINVOKESTATIC(INVOKESTATIC o){
try {
// INVOKESTATIC is a LoadClass; the Class where the referenced method is declared in,
// is therefore resolved/verified.
// INVOKESTATIC is an InvokeInstruction, the argument and return types are resolved/verified,
// too. So are the allowed method names.
String classname = o.getClassName(cpg);
JavaClass jc = Repository.lookupClass(classname);
Method[] ms = jc.getMethods();
Method m = null;
for (int i=0; i<ms.length; i++){
if ( (ms[i].getName().equals(o.getMethodName(cpg))) &&
(Type.getReturnType(ms[i].getSignature()).equals(o.getReturnType(cpg))) &&
(objarrayequals(Type.getArgumentTypes(ms[i].getSignature()), o.getArgumentTypes(cpg))) ){
m = ms[i];
break;
}
}
if (m == null){
constraintViolated(o, "Referenced method '"+o.getMethodName(cpg)+"' with expected signature '"+o.getSignature(cpg) +"' not found in class '"+jc.getClassName()+"'. The native verifier possibly allows the method to be declared in some superclass or implemented interface, which the Java Virtual Machine Specification, Second Edition does not.");
} else if (! (m.isStatic())){ // implies it's not abstract, verified in pass 2.
constraintViolated(o, "Referenced method '"+o.getMethodName(cpg)+"' has ACC_STATIC unset.");
}
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
public void visitINVOKEVIRTUAL(INVOKEVIRTUAL o){
try {
// INVOKEVIRTUAL is a LoadClass; the Class where the referenced method is declared in,
// is therefore resolved/verified.
// INVOKEVIRTUAL is an InvokeInstruction, the argument and return types are resolved/verified,
// too. So are the allowed method names.
String classname = o.getClassName(cpg);
JavaClass jc = Repository.lookupClass(classname);
Method[] ms = jc.getMethods();
Method m = null;
for (int i=0; i<ms.length; i++){
if ( (ms[i].getName().equals(o.getMethodName(cpg))) &&
(Type.getReturnType(ms[i].getSignature()).equals(o.getReturnType(cpg))) &&
(objarrayequals(Type.getArgumentTypes(ms[i].getSignature()), o.getArgumentTypes(cpg))) ){
m = ms[i];
break;
}
}
if (m == null){
constraintViolated(o, "Referenced method '"+o.getMethodName(cpg)+"' with expected signature '"+o.getSignature(cpg)+"' not found in class '"+jc.getClassName()+"'. The native verifier does allow the method to be declared in some superclass or implemented interface, which the Java Virtual Machine Specification, Second Edition does not.");
}
if (! (jc.isClass())){
constraintViolated(o, "Referenced class '"+jc.getClassName()+"' is an interface, but not a class as expected.");
}
} catch (ClassNotFoundException e) {
// FIXME: maybe not the best way to handle this
throw new AssertionViolatedException("Missing class: " + e.toString());
}
}
// WIDE stuff is BCEL-internal and cannot be checked here.
/**
* A utility method like equals(Object) for arrays.
* The equality of the elements is based on their equals(Object)
* method instead of their object identity.
*/
private boolean objarrayequals(Object[] o, Object[] p){
if (o.length != p.length){
return false;
}
for (int i=0; i<o.length; i++){
if (! (o[i].equals(p[i])) ){
return false;
}
}
return true;
}
}
}