Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.commons.bcel6.verifier.structurals; import org.apache.commons.bcel6.Constants; import org.apache.commons.bcel6.Repository; import org.apache.commons.bcel6.classfile.Constant; import org.apache.commons.bcel6.classfile.ConstantClass; import org.apache.commons.bcel6.classfile.ConstantDouble; import org.apache.commons.bcel6.classfile.ConstantFieldref; import org.apache.commons.bcel6.classfile.ConstantFloat; import org.apache.commons.bcel6.classfile.ConstantInteger; import org.apache.commons.bcel6.classfile.ConstantLong; import org.apache.commons.bcel6.classfile.ConstantString; import org.apache.commons.bcel6.classfile.Field; import org.apache.commons.bcel6.classfile.JavaClass; import org.apache.commons.bcel6.generic.*; import org.apache.commons.bcel6.verifier.VerificationResult; import org.apache.commons.bcel6.verifier.Verifier; import org.apache.commons.bcel6.verifier.VerifierFactory; import org.apache.commons.bcel6.verifier.exc.AssertionViolatedException; import org.apache.commons.bcel6.verifier.exc.StructuralCodeConstraintException; /** * A Visitor class testing for valid preconditions of JVM instructions. * The instance of this class will throw a StructuralCodeConstraintException * instance if an instruction is visitXXX()ed which has preconditions that are * not satisfied. * TODO: Currently, the JVM's behaviour concerning monitors (MONITORENTER, * MONITOREXIT) is not modeled in JustIce. * * @version $Id$ * @author Enver Haase * @see org.apache.commons.bcel6.verifier.exc.StructuralCodeConstraintException * @see org.apache.commons.bcel6.verifier.exc.LinkingConstraintException */ public class InstConstraintVisitor extends EmptyVisitor { private static final ObjectType GENERIC_ARRAY = ObjectType .getInstance("org.apache.commons.bcel6.verifier.structurals.GenericArray"); /** * The constructor. Constructs a new instance of this class. */ public InstConstraintVisitor() { } /** * The Execution Frame we're working on. * * @see #setFrame(Frame f) * @see #locals() * @see #stack() */ private Frame frame = null; /** * The ConstantPoolGen we're working on. * * @see #setConstantPoolGen(ConstantPoolGen cpg) */ private ConstantPoolGen cpg = null; /** * The MethodGen we're working on. * * @see #setMethodGen(MethodGen mg) */ private MethodGen mg = null; /** * The OperandStack we're working on. * * @see #setFrame(Frame f) */ private OperandStack stack() { return frame.getStack(); } /** * The LocalVariables we're working on. * * @see #setFrame(Frame f) */ private LocalVariables locals() { return frame.getLocals(); } /** * This method is called by the visitXXX() to notify the acceptor of this InstConstraintVisitor * that a constraint violation has occured. This is done by throwing an instance of a * StructuralCodeConstraintException. * @throws org.apache.commons.bcel6.verifier.exc.StructuralCodeConstraintException always. */ private void constraintViolated(Instruction violator, String description) { String fq_classname = violator.getClass().getName(); throw new StructuralCodeConstraintException( "Instruction " + fq_classname.substring(fq_classname.lastIndexOf('.') + 1) + " constraint violated: " + description); } /** * This returns the single instance of the InstConstraintVisitor class. * To operate correctly, other values must have been set before actually * using the instance. * Use this method for performance reasons. * * @see #setConstantPoolGen(ConstantPoolGen cpg) * @see #setMethodGen(MethodGen mg) */ public void setFrame(Frame f) { this.frame = f; //if (singleInstance.mg == null || singleInstance.cpg == null) throw new AssertionViolatedException("Forgot to set important values first."); } /** * Sets the ConstantPoolGen instance needed for constraint * checking prior to execution. */ public void setConstantPoolGen(ConstantPoolGen cpg) { this.cpg = cpg; } /** * Sets the MethodGen instance needed for constraint * checking prior to execution. */ public void setMethodGen(MethodGen mg) { this.mg = mg; } /** * Assures index is of type INT. * @throws org.apache.commons.bcel6.verifier.exc.StructuralCodeConstraintException if the above constraint is not satisfied. */ private void indexOfInt(Instruction o, Type index) { if (!index.equals(Type.INT)) { constraintViolated(o, "The 'index' is not of type int but of type " + index + "."); } } /** * Assures the ReferenceType r is initialized (or Type.NULL). * Formally, this means (!(r instanceof UninitializedObjectType)), because * there are no uninitialized array types. * @throws org.apache.commons.bcel6.verifier.exc.StructuralCodeConstraintException if the above constraint is not satisfied. */ private void referenceTypeIsInitialized(Instruction o, ReferenceType r) { if (r instanceof UninitializedObjectType) { constraintViolated(o, "Working on an uninitialized object '" + r + "'."); } } /** Assures value is of type INT. */ private void valueOfInt(Instruction o, Type value) { if (!value.equals(Type.INT)) { constraintViolated(o, "The 'value' is not of type int but of type " + value + "."); } } /** * Assures arrayref is of ArrayType or NULL; * returns true if and only if arrayref is non-NULL. * @throws org.apache.commons.bcel6.verifier.exc.StructuralCodeConstraintException if the above constraint is violated. */ private boolean arrayrefOfArrayType(Instruction o, Type arrayref) { if (!((arrayref instanceof ArrayType) || arrayref.equals(Type.NULL))) { constraintViolated(o, "The 'arrayref' does not refer to an array but is of type " + arrayref + "."); } return (arrayref instanceof ArrayType); } /***************************************************************/ /* MISC */ /***************************************************************/ /** * Ensures the general preconditions of an instruction that accesses the stack. * This method is here because BCEL has no such superinterface for the stack * accessing instructions; and there are funny unexpected exceptions in the * semantices of the superinterfaces and superclasses provided. * E.g. SWAP is a StackConsumer, but DUP_X1 is not a StackProducer. * Therefore, this method is called by all StackProducer, StackConsumer, * and StackInstruction instances via their visitXXX() method. * Unfortunately, as the superclasses and superinterfaces overlap, some instructions * cause this method to be called two or three times. [TODO: Fix this.] * * @see #visitStackConsumer(StackConsumer o) * @see #visitStackProducer(StackProducer o) * @see #visitStackInstruction(StackInstruction o) */ private void _visitStackAccessor(Instruction o) { int consume = o.consumeStack(cpg); // Stack values are always consumed first; then produced. if (consume > stack().slotsUsed()) { constraintViolated(o, "Cannot consume " + consume + " stack slots: only " + stack().slotsUsed() + " slot(s) left on stack!\nStack:\n" + stack()); } int produce = o.produceStack(cpg) - o.consumeStack(cpg); // Stack values are always consumed first; then produced. if (produce + stack().slotsUsed() > stack().maxStack()) { constraintViolated(o, "Cannot produce " + produce + " stack slots: only " + (stack().maxStack() - stack().slotsUsed()) + " free stack slot(s) left.\nStack:\n" + stack()); } } /***************************************************************/ /* "generic"visitXXXX methods where XXXX is an interface */ /* therefore, we don't know the order of visiting; but we know */ /* these methods are called before the visitYYYY methods below */ /***************************************************************/ /** * Assures the generic preconditions of a LoadClass instance. * The referenced class is loaded and pass2-verified. */ @Override 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.doPass2(); if (vr.getStatus() != VerificationResult.VERIFIED_OK) { constraintViolated((Instruction) o, "Class '" + o.getLoadClassType(cpg).getClassName() + "' is referenced, but cannot be loaded and resolved: '" + vr + "'."); } } } /** * Ensures the general preconditions of a StackConsumer instance. */ @Override public void visitStackConsumer(StackConsumer o) { _visitStackAccessor((Instruction) o); } /** * Ensures the general preconditions of a StackProducer instance. */ @Override public void visitStackProducer(StackProducer o) { _visitStackAccessor((Instruction) o); } /***************************************************************/ /* "generic" visitYYYY methods where YYYY is a superclass. */ /* therefore, we know the order of visiting; we know */ /* these methods are called after the visitXXXX methods above. */ /***************************************************************/ /** * Ensures the general preconditions of a CPInstruction instance. */ @Override public void visitCPInstruction(CPInstruction o) { int idx = o.getIndex(); if ((idx < 0) || (idx >= cpg.getSize())) { throw new AssertionViolatedException("Huh?! Constant pool index of instruction '" + o + "' illegal? Pass 3a should have checked this!"); } } /** * Ensures the general preconditions of a FieldInstruction instance. */ @Override public void visitFieldInstruction(FieldInstruction o) { // visitLoadClass(o) has been called before: Every FieldOrMethod // implements LoadClass. // visitCPInstruction(o) has been called before. // A FieldInstruction may be: GETFIELD, GETSTATIC, PUTFIELD, PUTSTATIC Constant c = cpg.getConstant(o.getIndex()); if (!(c instanceof ConstantFieldref)) { constraintViolated(o, "Index '" + o.getIndex() + "' should refer to a CONSTANT_Fieldref_info structure, but refers to '" + c + "'."); } // the o.getClassType(cpg) type has passed pass 2; see visitLoadClass(o). Type t = o.getType(cpg); if (t instanceof ObjectType) { String name = ((ObjectType) t).getClassName(); Verifier v = VerifierFactory.getVerifier(name); VerificationResult vr = v.doPass2(); if (vr.getStatus() != VerificationResult.VERIFIED_OK) { constraintViolated(o, "Class '" + name + "' is referenced, but cannot be loaded and resolved: '" + vr + "'."); } } } /** * Ensures the general preconditions of an InvokeInstruction instance. */ @Override public void visitInvokeInstruction(InvokeInstruction o) { // visitLoadClass(o) has been called before: Every FieldOrMethod // implements LoadClass. // visitCPInstruction(o) has been called before. //TODO } /** * Ensures the general preconditions of a StackInstruction instance. */ @Override public void visitStackInstruction(StackInstruction o) { _visitStackAccessor(o); } /** * Assures the generic preconditions of a LocalVariableInstruction instance. * That is, the index of the local variable must be valid. */ @Override public void visitLocalVariableInstruction(LocalVariableInstruction o) { if (locals().maxLocals() <= (o.getType(cpg).getSize() == 1 ? o.getIndex() : o.getIndex() + 1)) { constraintViolated(o, "The 'index' is not a valid index into the local variable array."); } } /** * Assures the generic preconditions of a LoadInstruction instance. */ @Override public void visitLoadInstruction(LoadInstruction o) { //visitLocalVariableInstruction(o) is called before, because it is more generic. // LOAD instructions must not read Type.UNKNOWN if (locals().get(o.getIndex()) == Type.UNKNOWN) { constraintViolated(o, "Read-Access on local variable " + o.getIndex() + " with unknown content."); } // LOAD instructions, two-slot-values at index N must have Type.UNKNOWN // as a symbol for the higher halve at index N+1 // [suppose some instruction put an int at N+1--- our double at N is defective] if (o.getType(cpg).getSize() == 2) { if (locals().get(o.getIndex() + 1) != Type.UNKNOWN) { constraintViolated(o, "Reading a two-locals value from local variables " + o.getIndex() + " and " + (o.getIndex() + 1) + " where the latter one is destroyed."); } } // LOAD instructions must read the correct type. if (!(o instanceof ALOAD)) { if (locals().get(o.getIndex()) != o.getType(cpg)) { constraintViolated(o, "Local Variable type and LOADing Instruction type mismatch: Local Variable: '" + locals().get(o.getIndex()) + "'; Instruction type: '" + o.getType(cpg) + "'."); } } else { // we deal with an ALOAD if (!(locals().get(o.getIndex()) instanceof ReferenceType)) { constraintViolated(o, "Local Variable type and LOADing Instruction type mismatch: Local Variable: '" + locals().get(o.getIndex()) + "'; Instruction expects a ReferenceType."); } // ALOAD __IS ALLOWED__ to put uninitialized objects onto the stack! //referenceTypeIsInitialized(o, (ReferenceType) (locals().get(o.getIndex()))); } // LOAD instructions must have enough free stack slots. if ((stack().maxStack() - stack().slotsUsed()) < o.getType(cpg).getSize()) { constraintViolated(o, "Not enough free stack slots to load a '" + o.getType(cpg) + "' onto the OperandStack."); } } /** * Assures the generic preconditions of a StoreInstruction instance. */ @Override public void visitStoreInstruction(StoreInstruction o) { //visitLocalVariableInstruction(o) is called before, because it is more generic. if (stack().isEmpty()) { // Don't bother about 1 or 2 stack slots used. This check is implicitely done below while type checking. constraintViolated(o, "Cannot STORE: Stack to read from is empty."); } if ((!(o instanceof ASTORE))) { if (!(stack().peek() == o.getType(cpg))) {// the other xSTORE types are singletons in BCEL. constraintViolated(o, "Stack top type and STOREing Instruction type mismatch: Stack top: '" + stack().peek() + "'; Instruction type: '" + o.getType(cpg) + "'."); } } else { // we deal with ASTORE Type stacktop = stack().peek(); if ((!(stacktop instanceof ReferenceType)) && (!(stacktop instanceof ReturnaddressType))) { constraintViolated(o, "Stack top type and STOREing Instruction type mismatch: Stack top: '" + stack().peek() + "'; Instruction expects a ReferenceType or a ReturnadressType."); } //if (stacktop instanceof ReferenceType){ // referenceTypeIsInitialized(o, (ReferenceType) stacktop); //} } } /** * Assures the generic preconditions of a ReturnInstruction instance. */ @Override public void visitReturnInstruction(ReturnInstruction o) { Type method_type = mg.getType(); if (method_type == Type.BOOLEAN || method_type == Type.BYTE || method_type == Type.SHORT || method_type == Type.CHAR) { method_type = Type.INT; } if (o instanceof RETURN) { if (method_type != Type.VOID) { constraintViolated(o, "RETURN instruction in non-void method."); } else { return; } } if (o instanceof ARETURN) { if (method_type == Type.VOID) { constraintViolated(o, "ARETURN instruction in void method."); } if (stack().peek() == Type.NULL) { return; } if (!(stack().peek() instanceof ReferenceType)) { constraintViolated(o, "Reference type expected on top of stack, but is: '" + stack().peek() + "'."); } referenceTypeIsInitialized(o, (ReferenceType) (stack().peek())); //ReferenceType objectref = (ReferenceType) (stack().peek()); // TODO: This can only be checked if using Staerk-et-al's "set of object types" instead of a // "wider cast object type" created during verification. //if (! (objectref.isAssignmentCompatibleWith(mg.getType())) ){ // constraintViolated(o, "Type on stack top which should be returned is a '"+stack().peek()+"' which is not assignment compatible with the return type of this method, '"+mg.getType()+"'."); //} } else { if (!(method_type.equals(stack().peek()))) { constraintViolated(o, "Current method has return type of '" + mg.getType() + "' expecting a '" + method_type + "' on top of the stack. But stack top is a '" + stack().peek() + "'."); } } } /***************************************************************/ /* "special"visitXXXX methods for one type of instruction each */ /***************************************************************/ /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitAALOAD(AALOAD o) { Type arrayref = stack().peek(1); Type index = stack().peek(0); indexOfInt(o, index); if (arrayrefOfArrayType(o, arrayref)) { if (!(((ArrayType) arrayref).getElementType() instanceof ReferenceType)) { constraintViolated(o, "The 'arrayref' does not refer to an array with elements of a ReferenceType but to an array of " + ((ArrayType) arrayref).getElementType() + "."); } //referenceTypeIsInitialized(o, (ReferenceType) (((ArrayType) arrayref).getElementType())); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitAASTORE(AASTORE o) { Type arrayref = stack().peek(2); Type index = stack().peek(1); Type value = stack().peek(0); indexOfInt(o, index); if (!(value instanceof ReferenceType)) { constraintViolated(o, "The 'value' is not of a ReferenceType but of type " + value + "."); } else { //referenceTypeIsInitialized(o, (ReferenceType) value); } // Don't bother further with "referenceTypeIsInitialized()", there are no arrays // of an uninitialized object type. if (arrayrefOfArrayType(o, arrayref)) { if (!(((ArrayType) arrayref).getElementType() instanceof ReferenceType)) { constraintViolated(o, "The 'arrayref' does not refer to an array with elements of a ReferenceType but to an array of " + ((ArrayType) arrayref).getElementType() + "."); } // No check for array element assignment compatibility. This is done at runtime. } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitACONST_NULL(ACONST_NULL o) { // Nothing needs to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitALOAD(ALOAD o) { //visitLoadInstruction(LoadInstruction) is called before. // Nothing else needs to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitANEWARRAY(ANEWARRAY o) { if (!stack().peek().equals(Type.INT)) { constraintViolated(o, "The 'count' at the stack top is not of type '" + Type.INT + "' but of type '" + stack().peek() + "'."); // The runtime constant pool item at that index must be a symbolic reference to a class, // array, or interface type. See Pass 3a. } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitARETURN(ARETURN o) { if (!(stack().peek() instanceof ReferenceType)) { constraintViolated(o, "The 'objectref' at the stack top is not of a ReferenceType but of type '" + stack().peek() + "'."); } ReferenceType objectref = (ReferenceType) (stack().peek()); referenceTypeIsInitialized(o, objectref); // The check below should already done via visitReturnInstruction(ReturnInstruction), see there. // It cannot be done using Staerk-et-al's "set of object types" instead of a // "wider cast object type", anyway. //if (! objectref.isAssignmentCompatibleWith(mg.getReturnType() )){ // constraintViolated(o, "The 'objectref' type "+objectref+" at the stack top is not assignment compatible with the return type '"+mg.getReturnType()+"' of the method."); //} } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitARRAYLENGTH(ARRAYLENGTH o) { Type arrayref = stack().peek(0); arrayrefOfArrayType(o, arrayref); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitASTORE(ASTORE o) { if (!((stack().peek() instanceof ReferenceType) || (stack().peek() instanceof ReturnaddressType))) { constraintViolated(o, "The 'objectref' is not of a ReferenceType or of ReturnaddressType but of " + stack().peek() + "."); } //if (stack().peek() instanceof ReferenceType){ // referenceTypeIsInitialized(o, (ReferenceType) (stack().peek()) ); //} } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitATHROW(ATHROW o) { try { // It's stated that 'objectref' must be of a ReferenceType --- but since Throwable is // not derived from an ArrayType, it follows that 'objectref' must be of an ObjectType or Type.NULL. if (!((stack().peek() instanceof ObjectType) || (stack().peek().equals(Type.NULL)))) { constraintViolated(o, "The 'objectref' is not of an (initialized) ObjectType but of type " + stack().peek() + "."); } // NULL is a subclass of every class, so to speak. if (stack().peek().equals(Type.NULL)) { return; } ObjectType exc = (ObjectType) (stack().peek()); ObjectType throwable = (ObjectType) (Type.getType("Ljava/lang/Throwable;")); if ((!(exc.subclassOf(throwable))) && (!(exc.equals(throwable)))) { constraintViolated(o, "The 'objectref' is not of class Throwable or of a subclass of Throwable, but of '" + stack().peek() + "'."); } } catch (ClassNotFoundException e) { // FIXME: maybe not the best way to handle this throw new AssertionViolatedException("Missing class: " + e, e); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitBALOAD(BALOAD o) { Type arrayref = stack().peek(1); Type index = stack().peek(0); indexOfInt(o, index); if (arrayrefOfArrayType(o, arrayref)) { if (!((((ArrayType) arrayref).getElementType().equals(Type.BOOLEAN)) || (((ArrayType) arrayref).getElementType().equals(Type.BYTE)))) { constraintViolated(o, "The 'arrayref' does not refer to an array with elements of a Type.BYTE or Type.BOOLEAN but to an array of '" + ((ArrayType) arrayref).getElementType() + "'."); } } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitBASTORE(BASTORE o) { Type arrayref = stack().peek(2); Type index = stack().peek(1); Type value = stack().peek(0); indexOfInt(o, index); valueOfInt(o, value); if (arrayrefOfArrayType(o, arrayref)) { if (!((((ArrayType) arrayref).getElementType().equals(Type.BOOLEAN)) || (((ArrayType) arrayref).getElementType().equals(Type.BYTE)))) { constraintViolated(o, "The 'arrayref' does not refer to an array with elements of a Type.BYTE or Type.BOOLEAN but to an array of '" + ((ArrayType) arrayref).getElementType() + "'."); } } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitBIPUSH(BIPUSH o) { // Nothing to do... } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitBREAKPOINT(BREAKPOINT o) { throw new AssertionViolatedException( "In this JustIce verification pass there should not occur an illegal instruction such as BREAKPOINT."); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitCALOAD(CALOAD o) { Type arrayref = stack().peek(1); Type index = stack().peek(0); indexOfInt(o, index); arrayrefOfArrayType(o, arrayref); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitCASTORE(CASTORE o) { Type arrayref = stack().peek(2); Type index = stack().peek(1); Type value = stack().peek(0); indexOfInt(o, index); valueOfInt(o, value); if (arrayrefOfArrayType(o, arrayref)) { if (!((ArrayType) arrayref).getElementType().equals(Type.CHAR)) { constraintViolated(o, "The 'arrayref' does not refer to an array with elements of type char but to an array of type " + ((ArrayType) arrayref).getElementType() + "."); } } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitCHECKCAST(CHECKCAST o) { // The objectref must be of type reference. Type objectref = stack().peek(0); if (!(objectref instanceof ReferenceType)) { constraintViolated(o, "The 'objectref' is not of a ReferenceType but of type " + objectref + "."); } //else{ // referenceTypeIsInitialized(o, (ReferenceType) objectref); //} // The unsigned indexbyte1 and indexbyte2 are used to construct an index into the runtime constant pool of the // current class (3.6), where the value of the index is (indexbyte1 << 8) | indexbyte2. The runtime constant // pool item at the index must be a symbolic reference to a class, array, or interface type. Constant c = cpg.getConstant(o.getIndex()); if (!(c instanceof ConstantClass)) { constraintViolated(o, "The Constant at 'index' is not a ConstantClass, but '" + c + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitD2F(D2F o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitD2I(D2I o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitD2L(D2L o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDADD(DADD o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.DOUBLE) { constraintViolated(o, "The value at the stack next-to-top is not of type 'double', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDALOAD(DALOAD o) { indexOfInt(o, stack().peek()); if (stack().peek(1) == Type.NULL) { return; } if (!(stack().peek(1) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-top must be of type double[] but is '" + stack().peek(1) + "'."); } Type t = ((ArrayType) (stack().peek(1))).getBasicType(); if (t != Type.DOUBLE) { constraintViolated(o, "Stack next-to-top must be of type double[] but is '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDASTORE(DASTORE o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } indexOfInt(o, stack().peek(1)); if (stack().peek(2) == Type.NULL) { return; } if (!(stack().peek(2) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-next-to-top must be of type double[] but is '" + stack().peek(2) + "'."); } Type t = ((ArrayType) (stack().peek(2))).getBasicType(); if (t != Type.DOUBLE) { constraintViolated(o, "Stack next-to-next-to-top must be of type double[] but is '" + stack().peek(2) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDCMPG(DCMPG o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.DOUBLE) { constraintViolated(o, "The value at the stack next-to-top is not of type 'double', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDCMPL(DCMPL o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.DOUBLE) { constraintViolated(o, "The value at the stack next-to-top is not of type 'double', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDCONST(DCONST o) { // There's nothing to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDDIV(DDIV o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.DOUBLE) { constraintViolated(o, "The value at the stack next-to-top is not of type 'double', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDLOAD(DLOAD o) { //visitLoadInstruction(LoadInstruction) is called before. // Nothing else needs to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDMUL(DMUL o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.DOUBLE) { constraintViolated(o, "The value at the stack next-to-top is not of type 'double', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDNEG(DNEG o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDREM(DREM o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.DOUBLE) { constraintViolated(o, "The value at the stack next-to-top is not of type 'double', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDRETURN(DRETURN o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDSTORE(DSTORE o) { //visitStoreInstruction(StoreInstruction) is called before. // Nothing else needs to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDSUB(DSUB o) { if (stack().peek() != Type.DOUBLE) { constraintViolated(o, "The value at the stack top is not of type 'double', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.DOUBLE) { constraintViolated(o, "The value at the stack next-to-top is not of type 'double', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDUP(DUP o) { if (stack().peek().getSize() != 1) { constraintViolated(o, "Won't DUP type on stack top '" + stack().peek() + "' because it must occupy exactly one slot, not '" + stack().peek().getSize() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDUP_X1(DUP_X1 o) { if (stack().peek().getSize() != 1) { constraintViolated(o, "Type on stack top '" + stack().peek() + "' should occupy exactly one slot, not '" + stack().peek().getSize() + "'."); } if (stack().peek(1).getSize() != 1) { constraintViolated(o, "Type on stack next-to-top '" + stack().peek(1) + "' should occupy exactly one slot, not '" + stack().peek(1).getSize() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDUP_X2(DUP_X2 o) { if (stack().peek().getSize() != 1) { constraintViolated(o, "Stack top type must be of size 1, but is '" + stack().peek() + "' of size '" + stack().peek().getSize() + "'."); } if (stack().peek(1).getSize() == 2) { return; // Form 2, okay. } //stack().peek(1).getSize == 1. if (stack().peek(2).getSize() != 1) { constraintViolated(o, "If stack top's size is 1 and stack next-to-top's size is 1, stack next-to-next-to-top's size must also be 1, but is: '" + stack().peek(2) + "' of size '" + stack().peek(2).getSize() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDUP2(DUP2 o) { if (stack().peek().getSize() == 2) { return; // Form 2, okay. } //stack().peek().getSize() == 1. if (stack().peek(1).getSize() != 1) { constraintViolated(o, "If stack top's size is 1, then stack next-to-top's size must also be 1. But it is '" + stack().peek(1) + "' of size '" + stack().peek(1).getSize() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDUP2_X1(DUP2_X1 o) { if (stack().peek().getSize() == 2) { if (stack().peek(1).getSize() != 1) { constraintViolated(o, "If stack top's size is 2, then stack next-to-top's size must be 1. But it is '" + stack().peek(1) + "' of size '" + stack().peek(1).getSize() + "'."); } else { return; // Form 2 } } else { // stack top is of size 1 if (stack().peek(1).getSize() != 1) { constraintViolated(o, "If stack top's size is 1, then stack next-to-top's size must also be 1. But it is '" + stack().peek(1) + "' of size '" + stack().peek(1).getSize() + "'."); } if (stack().peek(2).getSize() != 1) { constraintViolated(o, "If stack top's size is 1, then stack next-to-next-to-top's size must also be 1. But it is '" + stack().peek(2) + "' of size '" + stack().peek(2).getSize() + "'."); } } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitDUP2_X2(DUP2_X2 o) { if (stack().peek(0).getSize() == 2) { if (stack().peek(1).getSize() == 2) { return; // Form 4 } // stack top size is 2, next-to-top's size is 1 if (stack().peek(2).getSize() != 1) { constraintViolated(o, "If stack top's size is 2 and stack-next-to-top's size is 1, then stack next-to-next-to-top's size must also be 1. But it is '" + stack().peek(2) + "' of size '" + stack().peek(2).getSize() + "'."); } else { return; // Form 2 } } else {// stack top is of size 1 if (stack().peek(1).getSize() == 1) { if (stack().peek(2).getSize() == 2) { return; // Form 3 } if (stack().peek(3).getSize() == 1) { return; // Form 1 } } } constraintViolated(o, "The operand sizes on the stack do not match any of the four forms of usage of this instruction."); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitF2D(F2D o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitF2I(F2I o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitF2L(F2L o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFADD(FADD o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.FLOAT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'float', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFALOAD(FALOAD o) { indexOfInt(o, stack().peek()); if (stack().peek(1) == Type.NULL) { return; } if (!(stack().peek(1) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-top must be of type float[] but is '" + stack().peek(1) + "'."); } Type t = ((ArrayType) (stack().peek(1))).getBasicType(); if (t != Type.FLOAT) { constraintViolated(o, "Stack next-to-top must be of type float[] but is '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFASTORE(FASTORE o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } indexOfInt(o, stack().peek(1)); if (stack().peek(2) == Type.NULL) { return; } if (!(stack().peek(2) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-next-to-top must be of type float[] but is '" + stack().peek(2) + "'."); } Type t = ((ArrayType) (stack().peek(2))).getBasicType(); if (t != Type.FLOAT) { constraintViolated(o, "Stack next-to-next-to-top must be of type float[] but is '" + stack().peek(2) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFCMPG(FCMPG o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.FLOAT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'float', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFCMPL(FCMPL o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.FLOAT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'float', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFCONST(FCONST o) { // nothing to do here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFDIV(FDIV o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.FLOAT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'float', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFLOAD(FLOAD o) { //visitLoadInstruction(LoadInstruction) is called before. // Nothing else needs to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFMUL(FMUL o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.FLOAT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'float', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFNEG(FNEG o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFREM(FREM o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.FLOAT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'float', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFRETURN(FRETURN o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFSTORE(FSTORE o) { //visitStoreInstruction(StoreInstruction) is called before. // Nothing else needs to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitFSUB(FSUB o) { if (stack().peek() != Type.FLOAT) { constraintViolated(o, "The value at the stack top is not of type 'float', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.FLOAT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'float', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitGETFIELD(GETFIELD o) { try { Type objectref = stack().peek(); if (!((objectref instanceof ObjectType) || (objectref == Type.NULL))) { constraintViolated(o, "Stack top should be an object reference that's not an array reference, but is '" + objectref + "'."); } String field_name = o.getFieldName(cpg); JavaClass jc = Repository.lookupClass(o.getClassType(cpg).getClassName()); Field[] fields = jc.getFields(); Field f = null; for (Field field : fields) { if (field.getName().equals(field_name)) { Type f_type = Type.getType(field.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 = field; break; } } } if (f == null) { JavaClass[] superclasses = jc.getSuperClasses(); outer: for (JavaClass superclass : superclasses) { fields = superclass.getFields(); for (Field field : fields) { if (field.getName().equals(field_name)) { Type f_type = Type.getType(field.getSignature()); Type o_type = o.getType(cpg); if (f_type.equals(o_type)) { f = field; if ((f.getAccessFlags() & (Constants.ACC_PUBLIC | Constants.ACC_PROTECTED)) == 0) { f = null; } break outer; } } } } if (f == null) { throw new AssertionViolatedException( "Field '" + field_name + "' not found in " + jc.getClassName()); } } if (f.isProtected()) { ObjectType classtype = o.getClassType(cpg); ObjectType curr = ObjectType.getInstance(mg.getClassName()); if (classtype.equals(curr) || curr.subclassOf(classtype)) { Type t = stack().peek(); if (t == Type.NULL) { return; } if (!(t instanceof ObjectType)) { constraintViolated(o, "The 'objectref' must refer to an object that's not an array. Found instead: '" + t + "'."); } ObjectType objreftype = (ObjectType) t; if (!(objreftype.equals(curr) || objreftype.subclassOf(curr))) { //TODO: One day move to Staerk-et-al's "Set of object types" instead of "wider" object types // created during the verification. // "Wider" object types don't allow us to check for things like that below. //constraintViolated(o, "The referenced field has the ACC_PROTECTED modifier, and it's a member of the current class or a superclass of the current class. However, the referenced object type '"+stack().peek()+"' is not the current class or a subclass of the current class."); } } } // TODO: Could go into Pass 3a. if (f.isStatic()) { constraintViolated(o, "Referenced field '" + f + "' is static which it shouldn't be."); } } catch (ClassNotFoundException e) { // FIXME: maybe not the best way to handle this throw new AssertionViolatedException("Missing class: " + e, e); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitGETSTATIC(GETSTATIC o) { // Field must be static: see Pass 3a. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitGOTO(GOTO o) { // nothing to do here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitGOTO_W(GOTO_W o) { // nothing to do here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitI2B(I2B o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitI2C(I2C o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitI2D(I2D o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitI2F(I2F o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitI2L(I2L o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitI2S(I2S o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIADD(IADD o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIALOAD(IALOAD o) { indexOfInt(o, stack().peek()); if (stack().peek(1) == Type.NULL) { return; } if (!(stack().peek(1) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-top must be of type int[] but is '" + stack().peek(1) + "'."); } Type t = ((ArrayType) (stack().peek(1))).getBasicType(); if (t != Type.INT) { constraintViolated(o, "Stack next-to-top must be of type int[] but is '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIAND(IAND o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIASTORE(IASTORE o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } indexOfInt(o, stack().peek(1)); if (stack().peek(2) == Type.NULL) { return; } if (!(stack().peek(2) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-next-to-top must be of type int[] but is '" + stack().peek(2) + "'."); } Type t = ((ArrayType) (stack().peek(2))).getBasicType(); if (t != Type.INT) { constraintViolated(o, "Stack next-to-next-to-top must be of type int[] but is '" + stack().peek(2) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitICONST(ICONST o) { //nothing to do here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIDIV(IDIV o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIF_ACMPEQ(IF_ACMPEQ o) { if (!(stack().peek() instanceof ReferenceType)) { constraintViolated(o, "The value at the stack top is not of a ReferenceType, but of type '" + stack().peek() + "'."); } //referenceTypeIsInitialized(o, (ReferenceType) (stack().peek()) ); if (!(stack().peek(1) instanceof ReferenceType)) { constraintViolated(o, "The value at the stack next-to-top is not of a ReferenceType, but of type '" + stack().peek(1) + "'."); } //referenceTypeIsInitialized(o, (ReferenceType) (stack().peek(1)) ); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIF_ACMPNE(IF_ACMPNE o) { if (!(stack().peek() instanceof ReferenceType)) { constraintViolated(o, "The value at the stack top is not of a ReferenceType, but of type '" + stack().peek() + "'."); //referenceTypeIsInitialized(o, (ReferenceType) (stack().peek()) ); } if (!(stack().peek(1) instanceof ReferenceType)) { constraintViolated(o, "The value at the stack next-to-top is not of a ReferenceType, but of type '" + stack().peek(1) + "'."); //referenceTypeIsInitialized(o, (ReferenceType) (stack().peek(1)) ); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIF_ICMPEQ(IF_ICMPEQ o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIF_ICMPGE(IF_ICMPGE o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIF_ICMPGT(IF_ICMPGT o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIF_ICMPLE(IF_ICMPLE o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIF_ICMPLT(IF_ICMPLT o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIF_ICMPNE(IF_ICMPNE o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIFEQ(IFEQ o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIFGE(IFGE o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIFGT(IFGT o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIFLE(IFLE o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIFLT(IFLT o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIFNE(IFNE o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIFNONNULL(IFNONNULL o) { if (!(stack().peek() instanceof ReferenceType)) { constraintViolated(o, "The value at the stack top is not of a ReferenceType, but of type '" + stack().peek() + "'."); } referenceTypeIsInitialized(o, (ReferenceType) (stack().peek())); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIFNULL(IFNULL o) { if (!(stack().peek() instanceof ReferenceType)) { constraintViolated(o, "The value at the stack top is not of a ReferenceType, but of type '" + stack().peek() + "'."); } referenceTypeIsInitialized(o, (ReferenceType) (stack().peek())); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIINC(IINC o) { // Mhhh. In BCEL, at this time "IINC" is not a LocalVariableInstruction. if (locals().maxLocals() <= (o.getType(cpg).getSize() == 1 ? o.getIndex() : o.getIndex() + 1)) { constraintViolated(o, "The 'index' is not a valid index into the local variable array."); } indexOfInt(o, locals().get(o.getIndex())); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitILOAD(ILOAD o) { // All done by visitLocalVariableInstruction(), visitLoadInstruction() } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIMPDEP1(IMPDEP1 o) { throw new AssertionViolatedException( "In this JustIce verification pass there should not occur an illegal instruction such as IMPDEP1."); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIMPDEP2(IMPDEP2 o) { throw new AssertionViolatedException( "In this JustIce verification pass there should not occur an illegal instruction such as IMPDEP2."); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIMUL(IMUL o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitINEG(INEG o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitINSTANCEOF(INSTANCEOF o) { // The objectref must be of type reference. Type objectref = stack().peek(0); if (!(objectref instanceof ReferenceType)) { constraintViolated(o, "The 'objectref' is not of a ReferenceType but of type " + objectref + "."); } //else{ // referenceTypeIsInitialized(o, (ReferenceType) objectref); //} // The unsigned indexbyte1 and indexbyte2 are used to construct an index into the runtime constant pool of the // current class (3.6), where the value of the index is (indexbyte1 << 8) | indexbyte2. The runtime constant // pool item at the index must be a symbolic reference to a class, array, or interface type. Constant c = cpg.getConstant(o.getIndex()); if (!(c instanceof ConstantClass)) { constraintViolated(o, "The Constant at 'index' is not a ConstantClass, but '" + c + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitINVOKEDYNAMIC(INVOKEDYNAMIC o) { throw new RuntimeException("INVOKEDYNAMIC instruction is not supported at this time"); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitINVOKEINTERFACE(INVOKEINTERFACE o) { // Method is not native, otherwise pass 3 would not happen. int count = o.getCount(); if (count == 0) { constraintViolated(o, "The 'count' argument must not be 0."); } // It is a ConstantInterfaceMethodref, Pass 3a made it sure. // TODO: Do we want to do anything with it? //ConstantInterfaceMethodref cimr = (ConstantInterfaceMethodref) (cpg.getConstant(o.getIndex())); // the o.getClassType(cpg) type has passed pass 2; see visitLoadClass(o). Type t = o.getType(cpg); if (t instanceof ObjectType) { String name = ((ObjectType) t).getClassName(); Verifier v = VerifierFactory.getVerifier(name); VerificationResult vr = v.doPass2(); if (vr.getStatus() != VerificationResult.VERIFIED_OK) { constraintViolated(o, "Class '" + name + "' is referenced, but cannot be loaded and resolved: '" + vr + "'."); } } Type[] argtypes = o.getArgumentTypes(cpg); int nargs = argtypes.length; for (int i = nargs - 1; i >= 0; i--) { Type fromStack = stack().peek((nargs - 1) - i); // 0 to nargs-1 Type fromDesc = argtypes[i]; if (fromDesc == Type.BOOLEAN || fromDesc == Type.BYTE || fromDesc == Type.CHAR || fromDesc == Type.SHORT) { fromDesc = Type.INT; } if (!fromStack.equals(fromDesc)) { if (fromStack instanceof ReferenceType && fromDesc instanceof ReferenceType) { ReferenceType rFromStack = (ReferenceType) fromStack; //ReferenceType rFromDesc = (ReferenceType) fromDesc; // TODO: This can only be checked when using Staerk-et-al's "set of object types" // instead of a "wider cast object type" created during verification. //if ( ! rFromStack.isAssignmentCompatibleWith(rFromDesc) ){ // constraintViolated(o, "Expecting a '"+fromDesc+"' but found a '"+fromStack+"' on the stack (which is not assignment compatible)."); //} referenceTypeIsInitialized(o, rFromStack); } else { constraintViolated(o, "Expecting a '" + fromDesc + "' but found a '" + fromStack + "' on the stack."); } } } Type objref = stack().peek(nargs); if (objref == Type.NULL) { return; } if (!(objref instanceof ReferenceType)) { constraintViolated(o, "Expecting a reference type as 'objectref' on the stack, not a '" + objref + "'."); } referenceTypeIsInitialized(o, (ReferenceType) objref); if (!(objref instanceof ObjectType)) { if (!(objref instanceof ArrayType)) { constraintViolated(o, "Expecting an ObjectType as 'objectref' on the stack, not a '" + objref + "'."); // could be a ReturnaddressType } else { objref = GENERIC_ARRAY; } } // String objref_classname = ((ObjectType) objref).getClassName(); // String theInterface = o.getClassName(cpg); // TODO: This can only be checked if we're using Staerk-et-al's "set of object types" // instead of "wider cast object types" generated during verification. //if ( ! Repository.implementationOf(objref_classname, theInterface) ){ // constraintViolated(o, "The 'objref' item '"+objref+"' does not implement '"+theInterface+"' as expected."); //} int counted_count = 1; // 1 for the objectref for (int i = 0; i < nargs; i++) { counted_count += argtypes[i].getSize(); } if (count != counted_count) { constraintViolated(o, "The 'count' argument should probably read '" + counted_count + "' but is '" + count + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitINVOKESPECIAL(INVOKESPECIAL o) { try { // Don't init an object twice. if ((o.getMethodName(cpg).equals(Constants.CONSTRUCTOR_NAME)) && (!(stack().peek(o.getArgumentTypes(cpg).length) instanceof UninitializedObjectType))) { constraintViolated(o, "Possibly initializing object twice. A valid instruction sequence must not have an uninitialized object on the operand stack or in a local variable during a backwards branch, or in a local variable in code protected by an exception handler. Please see The Java Virtual Machine Specification, Second Edition, 4.9.4 (pages 147 and 148) for details."); } // the o.getClassType(cpg) type has passed pass 2; see visitLoadClass(o). Type t = o.getType(cpg); if (t instanceof ObjectType) { String name = ((ObjectType) t).getClassName(); Verifier v = VerifierFactory.getVerifier(name); VerificationResult vr = v.doPass2(); if (vr.getStatus() != VerificationResult.VERIFIED_OK) { constraintViolated(o, "Class '" + name + "' is referenced, but cannot be loaded and resolved: '" + vr + "'."); } } Type[] argtypes = o.getArgumentTypes(cpg); int nargs = argtypes.length; for (int i = nargs - 1; i >= 0; i--) { Type fromStack = stack().peek((nargs - 1) - i); // 0 to nargs-1 Type fromDesc = argtypes[i]; if (fromDesc == Type.BOOLEAN || fromDesc == Type.BYTE || fromDesc == Type.CHAR || fromDesc == Type.SHORT) { fromDesc = Type.INT; } if (!fromStack.equals(fromDesc)) { if (fromStack instanceof ReferenceType && fromDesc instanceof ReferenceType) { ReferenceType rFromStack = (ReferenceType) fromStack; ReferenceType rFromDesc = (ReferenceType) fromDesc; // TODO: This can only be checked using Staerk-et-al's "set of object types", not // using a "wider cast object type". if (!rFromStack.isAssignmentCompatibleWith(rFromDesc)) { constraintViolated(o, "Expecting a '" + fromDesc + "' but found a '" + fromStack + "' on the stack (which is not assignment compatible)."); } referenceTypeIsInitialized(o, rFromStack); } else { constraintViolated(o, "Expecting a '" + fromDesc + "' but found a '" + fromStack + "' on the stack."); } } } Type objref = stack().peek(nargs); if (objref == Type.NULL) { return; } if (!(objref instanceof ReferenceType)) { constraintViolated(o, "Expecting a reference type as 'objectref' on the stack, not a '" + objref + "'."); } String objref_classname = null; if (!(o.getMethodName(cpg).equals(Constants.CONSTRUCTOR_NAME))) { referenceTypeIsInitialized(o, (ReferenceType) objref); if (!(objref instanceof ObjectType)) { if (!(objref instanceof ArrayType)) { constraintViolated(o, "Expecting an ObjectType as 'objectref' on the stack, not a '" + objref + "'."); // could be a ReturnaddressType } else { objref = GENERIC_ARRAY; } } objref_classname = ((ObjectType) objref).getClassName(); } else { if (!(objref instanceof UninitializedObjectType)) { constraintViolated(o, "Expecting an UninitializedObjectType as 'objectref' on the stack, not a '" + objref + "'. Otherwise, you couldn't invoke a method since an array has no methods (not to speak of a return address)."); } objref_classname = ((UninitializedObjectType) objref).getInitialized().getClassName(); } String theClass = o.getClassName(cpg); if (!Repository.instanceOf(objref_classname, theClass)) { constraintViolated(o, "The 'objref' item '" + objref + "' does not implement '" + theClass + "' as expected."); } } catch (ClassNotFoundException e) { // FIXME: maybe not the best way to handle this throw new AssertionViolatedException("Missing class: " + e, e); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitINVOKESTATIC(INVOKESTATIC o) { try { // Method is not native, otherwise pass 3 would not happen. Type t = o.getType(cpg); if (t instanceof ObjectType) { String name = ((ObjectType) t).getClassName(); Verifier v = VerifierFactory.getVerifier(name); VerificationResult vr = v.doPass2(); if (vr.getStatus() != VerificationResult.VERIFIED_OK) { constraintViolated(o, "Class '" + name + "' is referenced, but cannot be loaded and resolved: '" + vr + "'."); } } Type[] argtypes = o.getArgumentTypes(cpg); int nargs = argtypes.length; for (int i = nargs - 1; i >= 0; i--) { Type fromStack = stack().peek((nargs - 1) - i); // 0 to nargs-1 Type fromDesc = argtypes[i]; if (fromDesc == Type.BOOLEAN || fromDesc == Type.BYTE || fromDesc == Type.CHAR || fromDesc == Type.SHORT) { fromDesc = Type.INT; } if (!fromStack.equals(fromDesc)) { if (fromStack instanceof ReferenceType && fromDesc instanceof ReferenceType) { ReferenceType rFromStack = (ReferenceType) fromStack; ReferenceType rFromDesc = (ReferenceType) fromDesc; // TODO: This check can possibly only be done using Staerk-et-al's "set of object types" // instead of a "wider cast object type" created during verification. if (!rFromStack.isAssignmentCompatibleWith(rFromDesc)) { constraintViolated(o, "Expecting a '" + fromDesc + "' but found a '" + fromStack + "' on the stack (which is not assignment compatible)."); } referenceTypeIsInitialized(o, rFromStack); } else { constraintViolated(o, "Expecting a '" + fromDesc + "' but found a '" + fromStack + "' on the stack."); } } } } catch (ClassNotFoundException e) { // FIXME: maybe not the best way to handle this throw new AssertionViolatedException("Missing class: " + e, e); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitINVOKEVIRTUAL(INVOKEVIRTUAL o) { try { // the o.getClassType(cpg) type has passed pass 2; see visitLoadClass(o). Type t = o.getType(cpg); if (t instanceof ObjectType) { String name = ((ObjectType) t).getClassName(); Verifier v = VerifierFactory.getVerifier(name); VerificationResult vr = v.doPass2(); if (vr.getStatus() != VerificationResult.VERIFIED_OK) { constraintViolated(o, "Class '" + name + "' is referenced, but cannot be loaded and resolved: '" + vr + "'."); } } Type[] argtypes = o.getArgumentTypes(cpg); int nargs = argtypes.length; for (int i = nargs - 1; i >= 0; i--) { Type fromStack = stack().peek((nargs - 1) - i); // 0 to nargs-1 Type fromDesc = argtypes[i]; if (fromDesc == Type.BOOLEAN || fromDesc == Type.BYTE || fromDesc == Type.CHAR || fromDesc == Type.SHORT) { fromDesc = Type.INT; } if (!fromStack.equals(fromDesc)) { if (fromStack instanceof ReferenceType && fromDesc instanceof ReferenceType) { ReferenceType rFromStack = (ReferenceType) fromStack; ReferenceType rFromDesc = (ReferenceType) fromDesc; // TODO: This can possibly only be checked when using Staerk-et-al's "set of object types" instead // of a single "wider cast object type" created during verification. if (!rFromStack.isAssignmentCompatibleWith(rFromDesc)) { constraintViolated(o, "Expecting a '" + fromDesc + "' but found a '" + fromStack + "' on the stack (which is not assignment compatible)."); } referenceTypeIsInitialized(o, rFromStack); } else { constraintViolated(o, "Expecting a '" + fromDesc + "' but found a '" + fromStack + "' on the stack."); } } } Type objref = stack().peek(nargs); if (objref == Type.NULL) { return; } if (!(objref instanceof ReferenceType)) { constraintViolated(o, "Expecting a reference type as 'objectref' on the stack, not a '" + objref + "'."); } referenceTypeIsInitialized(o, (ReferenceType) objref); if (!(objref instanceof ObjectType)) { if (!(objref instanceof ArrayType)) { constraintViolated(o, "Expecting an ObjectType as 'objectref' on the stack, not a '" + objref + "'."); // could be a ReturnaddressType } else { objref = GENERIC_ARRAY; } } String objref_classname = ((ObjectType) objref).getClassName(); String theClass = o.getClassName(cpg); if (!Repository.instanceOf(objref_classname, theClass)) { constraintViolated(o, "The 'objref' item '" + objref + "' does not implement '" + theClass + "' as expected."); } } catch (ClassNotFoundException e) { // FIXME: maybe not the best way to handle this throw new AssertionViolatedException("Missing class: " + e, e); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIOR(IOR o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIREM(IREM o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIRETURN(IRETURN o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitISHL(ISHL o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitISHR(ISHR o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitISTORE(ISTORE o) { //visitStoreInstruction(StoreInstruction) is called before. // Nothing else needs to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitISUB(ISUB o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIUSHR(IUSHR o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitIXOR(IXOR o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.INT) { constraintViolated(o, "The value at the stack next-to-top is not of type 'int', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitJSR(JSR o) { // nothing to do here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitJSR_W(JSR_W o) { // nothing to do here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitL2D(L2D o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitL2F(L2F o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitL2I(L2I o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLADD(LADD o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLALOAD(LALOAD o) { indexOfInt(o, stack().peek()); if (stack().peek(1) == Type.NULL) { return; } if (!(stack().peek(1) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-top must be of type long[] but is '" + stack().peek(1) + "'."); } Type t = ((ArrayType) (stack().peek(1))).getBasicType(); if (t != Type.LONG) { constraintViolated(o, "Stack next-to-top must be of type long[] but is '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLAND(LAND o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLASTORE(LASTORE o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } indexOfInt(o, stack().peek(1)); if (stack().peek(2) == Type.NULL) { return; } if (!(stack().peek(2) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-next-to-top must be of type long[] but is '" + stack().peek(2) + "'."); } Type t = ((ArrayType) (stack().peek(2))).getBasicType(); if (t != Type.LONG) { constraintViolated(o, "Stack next-to-next-to-top must be of type long[] but is '" + stack().peek(2) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLCMP(LCMP o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLCONST(LCONST o) { // Nothing to do here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLDC(LDC o) { // visitCPInstruction is called first. Constant c = cpg.getConstant(o.getIndex()); if (!((c instanceof ConstantInteger) || (c instanceof ConstantFloat) || (c instanceof ConstantString) || (c instanceof ConstantClass))) { constraintViolated(o, "Referenced constant should be a CONSTANT_Integer, a CONSTANT_Float, a CONSTANT_String or a CONSTANT_Class, but is '" + c + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ public void visitLDC_W(LDC_W o) { // visitCPInstruction is called first. Constant c = cpg.getConstant(o.getIndex()); if (!((c instanceof ConstantInteger) || (c instanceof ConstantFloat) || (c instanceof ConstantString) || (c instanceof ConstantClass))) { constraintViolated(o, "Referenced constant should be a CONSTANT_Integer, a CONSTANT_Float, a CONSTANT_String or a CONSTANT_Class, but is '" + c + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLDC2_W(LDC2_W o) { // visitCPInstruction is called first. Constant c = cpg.getConstant(o.getIndex()); if (!((c instanceof ConstantLong) || (c instanceof ConstantDouble))) { constraintViolated(o, "Referenced constant should be a CONSTANT_Integer, a CONSTANT_Float or a CONSTANT_String, but is '" + c + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLDIV(LDIV o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLLOAD(LLOAD o) { //visitLoadInstruction(LoadInstruction) is called before. // Nothing else needs to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLMUL(LMUL o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLNEG(LNEG o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLOOKUPSWITCH(LOOKUPSWITCH o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } // See also pass 3a. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLOR(LOR o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLREM(LREM o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLRETURN(LRETURN o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLSHL(LSHL o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLSHR(LSHR o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLSTORE(LSTORE o) { //visitStoreInstruction(StoreInstruction) is called before. // Nothing else needs to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLSUB(LSUB o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLUSHR(LUSHR o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitLXOR(LXOR o) { if (stack().peek() != Type.LONG) { constraintViolated(o, "The value at the stack top is not of type 'long', but of type '" + stack().peek() + "'."); } if (stack().peek(1) != Type.LONG) { constraintViolated(o, "The value at the stack next-to-top is not of type 'long', but of type '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitMONITORENTER(MONITORENTER o) { if (!((stack().peek()) instanceof ReferenceType)) { constraintViolated(o, "The stack top should be of a ReferenceType, but is '" + stack().peek() + "'."); } //referenceTypeIsInitialized(o, (ReferenceType) (stack().peek()) ); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitMONITOREXIT(MONITOREXIT o) { if (!((stack().peek()) instanceof ReferenceType)) { constraintViolated(o, "The stack top should be of a ReferenceType, but is '" + stack().peek() + "'."); } //referenceTypeIsInitialized(o, (ReferenceType) (stack().peek()) ); } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitMULTIANEWARRAY(MULTIANEWARRAY o) { int dimensions = o.getDimensions(); // Dimensions argument is okay: see Pass 3a. for (int i = 0; i < dimensions; i++) { if (stack().peek(i) != Type.INT) { constraintViolated(o, "The '" + dimensions + "' upper stack types should be 'int' but aren't."); } } // The runtime constant pool item at that index must be a symbolic reference to a class, // array, or interface type. See Pass 3a. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitNEW(NEW o) { //visitCPInstruction(CPInstruction) has been called before. //visitLoadClass(LoadClass) has been called before. Type t = o.getType(cpg); if (!(t instanceof ReferenceType)) { throw new AssertionViolatedException("NEW.getType() returning a non-reference type?!"); } if (!(t instanceof ObjectType)) { constraintViolated(o, "Expecting a class type (ObjectType) to work on. Found: '" + t + "'."); } ObjectType obj = (ObjectType) t; //e.g.: Don't instantiate interfaces if (!obj.referencesClass()) { constraintViolated(o, "Expecting a class type (ObjectType) to work on. Found: '" + obj + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitNEWARRAY(NEWARRAY o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitNOP(NOP o) { // nothing is to be done here. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitPOP(POP o) { if (stack().peek().getSize() != 1) { constraintViolated(o, "Stack top size should be 1 but stack top is '" + stack().peek() + "' of size '" + stack().peek().getSize() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitPOP2(POP2 o) { if (stack().peek().getSize() != 2) { constraintViolated(o, "Stack top size should be 2 but stack top is '" + stack().peek() + "' of size '" + stack().peek().getSize() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitPUTFIELD(PUTFIELD o) { try { Type objectref = stack().peek(1); if (!((objectref instanceof ObjectType) || (objectref == Type.NULL))) { constraintViolated(o, "Stack next-to-top should be an object reference that's not an array reference, but is '" + objectref + "'."); } String field_name = o.getFieldName(cpg); JavaClass jc = Repository.lookupClass(o.getClassType(cpg).getClassName()); Field[] fields = jc.getFields(); Field f = null; for (Field field : fields) { if (field.getName().equals(field_name)) { Type f_type = Type.getType(field.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 = field; break; } } } if (f == null) { throw new AssertionViolatedException( "Field '" + field_name + "' not found in " + jc.getClassName()); } Type value = stack().peek(); Type t = Type.getType(f.getSignature()); Type shouldbe = t; if (shouldbe == Type.BOOLEAN || shouldbe == Type.BYTE || shouldbe == Type.CHAR || shouldbe == Type.SHORT) { shouldbe = Type.INT; } if (t instanceof ReferenceType) { ReferenceType rvalue = null; if (value instanceof ReferenceType) { rvalue = (ReferenceType) value; referenceTypeIsInitialized(o, rvalue); } else { constraintViolated(o, "The stack top type '" + value + "' is not of a reference type as expected."); } // TODO: This can possibly only be checked using Staerk-et-al's "set-of-object types", not // using "wider cast object types" created during verification. // Comment it out if you encounter problems. See also the analogon at visitPUTSTATIC. if (!(rvalue.isAssignmentCompatibleWith(shouldbe))) { constraintViolated(o, "The stack top type '" + value + "' is not assignment compatible with '" + shouldbe + "'."); } } else { if (shouldbe != value) { constraintViolated(o, "The stack top type '" + value + "' is not of type '" + shouldbe + "' as expected."); } } if (f.isProtected()) { ObjectType classtype = o.getClassType(cpg); ObjectType curr = ObjectType.getInstance(mg.getClassName()); if (classtype.equals(curr) || curr.subclassOf(classtype)) { Type tp = stack().peek(1); if (tp == Type.NULL) { return; } if (!(tp instanceof ObjectType)) { constraintViolated(o, "The 'objectref' must refer to an object that's not an array. Found instead: '" + tp + "'."); } ObjectType objreftype = (ObjectType) tp; if (!(objreftype.equals(curr) || objreftype.subclassOf(curr))) { constraintViolated(o, "The referenced field has the ACC_PROTECTED modifier, and it's a member of the current class or a superclass of the current class. However, the referenced object type '" + stack().peek() + "' is not the current class or a subclass of the current class."); } } } // TODO: Could go into Pass 3a. if (f.isStatic()) { constraintViolated(o, "Referenced field '" + f + "' is static which it shouldn't be."); } } catch (ClassNotFoundException e) { // FIXME: maybe not the best way to handle this throw new AssertionViolatedException("Missing class: " + e, e); } } /** * Ensures the specific preconditions of the said instruction. */ @Override 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 (Field field : fields) { if (field.getName().equals(field_name)) { Type f_type = Type.getType(field.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 = field; break; } } } if (f == null) { throw new AssertionViolatedException( "Field '" + field_name + "' not found in " + jc.getClassName()); } Type value = stack().peek(); Type t = Type.getType(f.getSignature()); Type shouldbe = t; if (shouldbe == Type.BOOLEAN || shouldbe == Type.BYTE || shouldbe == Type.CHAR || shouldbe == Type.SHORT) { shouldbe = Type.INT; } if (t instanceof ReferenceType) { ReferenceType rvalue = null; if (value instanceof ReferenceType) { rvalue = (ReferenceType) value; referenceTypeIsInitialized(o, rvalue); } else { constraintViolated(o, "The stack top type '" + value + "' is not of a reference type as expected."); } // TODO: This can possibly only be checked using Staerk-et-al's "set-of-object types", not // using "wider cast object types" created during verification. // Comment it out if you encounter problems. See also the analogon at visitPUTFIELD. if (!(rvalue.isAssignmentCompatibleWith(shouldbe))) { constraintViolated(o, "The stack top type '" + value + "' is not assignment compatible with '" + shouldbe + "'."); } } else { if (shouldbe != value) { constraintViolated(o, "The stack top type '" + value + "' is not of type '" + shouldbe + "' as expected."); } } // TODO: Interface fields may be assigned to only once. (Hard to implement in // JustIce's execution model). This may only happen in <clinit>, see Pass 3a. } catch (ClassNotFoundException e) { // FIXME: maybe not the best way to handle this throw new AssertionViolatedException("Missing class: " + e, e); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitRET(RET o) { if (!(locals().get(o.getIndex()) instanceof ReturnaddressType)) { constraintViolated(o, "Expecting a ReturnaddressType in local variable " + o.getIndex() + "."); } if (locals().get(o.getIndex()) == ReturnaddressType.NO_TARGET) { throw new AssertionViolatedException("Oops: RET expecting a target!"); } // Other constraints such as non-allowed overlapping subroutines are enforced // while building the Subroutines data structure. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitRETURN(RETURN o) { if (mg.getName().equals(Constants.CONSTRUCTOR_NAME)) {// If we leave an <init> method if ((Frame._this != null) && (!(mg.getClassName().equals(Type.OBJECT.getClassName())))) { constraintViolated(o, "Leaving a constructor that itself did not call a constructor."); } } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitSALOAD(SALOAD o) { indexOfInt(o, stack().peek()); if (stack().peek(1) == Type.NULL) { return; } if (!(stack().peek(1) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-top must be of type short[] but is '" + stack().peek(1) + "'."); } Type t = ((ArrayType) (stack().peek(1))).getBasicType(); if (t != Type.SHORT) { constraintViolated(o, "Stack next-to-top must be of type short[] but is '" + stack().peek(1) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitSASTORE(SASTORE o) { if (stack().peek() != Type.INT) { constraintViolated(o, "The value at the stack top is not of type 'int', but of type '" + stack().peek() + "'."); } indexOfInt(o, stack().peek(1)); if (stack().peek(2) == Type.NULL) { return; } if (!(stack().peek(2) instanceof ArrayType)) { constraintViolated(o, "Stack next-to-next-to-top must be of type short[] but is '" + stack().peek(2) + "'."); } Type t = ((ArrayType) (stack().peek(2))).getBasicType(); if (t != Type.SHORT) { constraintViolated(o, "Stack next-to-next-to-top must be of type short[] but is '" + stack().peek(2) + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitSIPUSH(SIPUSH o) { // nothing to do here. Generic visitXXX() methods did the trick before. } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitSWAP(SWAP o) { if (stack().peek().getSize() != 1) { constraintViolated(o, "The value at the stack top is not of size '1', but of size '" + stack().peek().getSize() + "'."); } if (stack().peek(1).getSize() != 1) { constraintViolated(o, "The value at the stack next-to-top is not of size '1', but of size '" + stack().peek(1).getSize() + "'."); } } /** * Ensures the specific preconditions of the said instruction. */ @Override public void visitTABLESWITCH(TABLESWITCH o) { indexOfInt(o, stack().peek()); // See Pass 3a. } }