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.classfile.Constant; import org.apache.commons.bcel6.classfile.ConstantClass; import org.apache.commons.bcel6.classfile.ConstantDouble; 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.generic.*; /** * This Visitor class may be used for a type-based Java Virtual Machine * simulation. * * <p>It does not check for correct types on the OperandStack or in the * LocalVariables; nor does it check their sizes are sufficiently big. * Thus, to use this Visitor for bytecode verifying, you have to make sure * externally that the type constraints of the Java Virtual Machine instructions * are satisfied. An InstConstraintVisitor may be used for this. * Anyway, this Visitor does not mandate it. For example, when you * visitIADD(IADD o), then there are two stack slots popped and one * stack slot containing a Type.INT is pushed (where you could also * pop only one slot if you know there are two Type.INT on top of the * stack). Monitor-specific behaviour is not simulated.</p> * * <b>Conventions:</b> * * <p>Type.VOID will never be pushed onto the stack. Type.DOUBLE and Type.LONG * that would normally take up two stack slots (like Double_HIGH and * Double_LOW) are represented by a simple single Type.DOUBLE or Type.LONG * object on the stack here.</p> * * <p>If a two-slot type is stored into a local variable, the next variable * is given the type Type.UNKNOWN.</p> * * @version $Id$ * @author Enver Haase * @see #visitDSTORE(DSTORE o) * @see InstConstraintVisitor */ public class ExecutionVisitor extends EmptyVisitor { /** * The executionframe we're operating on. */ private Frame frame = null; /** * The ConstantPoolGen we're working with. * @see #setConstantPoolGen(ConstantPoolGen) */ private ConstantPoolGen cpg = null; /** * Constructor. Constructs a new instance of this class. */ public ExecutionVisitor() { } /** * The OperandStack from the current Frame we're operating on. * @see #setFrame(Frame) */ private OperandStack stack() { return frame.getStack(); } /** * The LocalVariables from the current Frame we're operating on. * @see #setFrame(Frame) */ private LocalVariables locals() { return frame.getLocals(); } /** * Sets the ConstantPoolGen needed for symbolic execution. */ public void setConstantPoolGen(ConstantPoolGen cpg) { this.cpg = cpg; } /** * The only method granting access to the single instance of * the ExecutionVisitor class. Before actively using this * instance, <B>SET THE ConstantPoolGen FIRST</B>. * @see #setConstantPoolGen(ConstantPoolGen) */ public void setFrame(Frame f) { this.frame = f; } ///** Symbolically executes the corresponding Java Virtual Machine instruction. */ //public void visitWIDE(WIDE o){ // The WIDE instruction is modelled as a flag // of the embedded instructions in BCEL. // Therefore BCEL checks for possible errors // when parsing in the .class file: We don't // have even the possibilty to care for WIDE // here. //} /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitAALOAD(AALOAD o) { stack().pop(); // pop the index int //System.out.print(stack().peek()); Type t = stack().pop(); // Pop Array type if (t == Type.NULL) { stack().push(Type.NULL); } // Do nothing stackwise --- a NullPointerException is thrown at Run-Time else { ArrayType at = (ArrayType) t; stack().push(at.getElementType()); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitAASTORE(AASTORE o) { stack().pop(); stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitACONST_NULL(ACONST_NULL o) { stack().push(Type.NULL); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitALOAD(ALOAD o) { stack().push(locals().get(o.getIndex())); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitANEWARRAY(ANEWARRAY o) { stack().pop(); //count stack().push(new ArrayType(o.getType(cpg), 1)); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitARETURN(ARETURN o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitARRAYLENGTH(ARRAYLENGTH o) { stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitASTORE(ASTORE o) { locals().set(o.getIndex(), stack().pop()); //System.err.println("TODO-DEBUG: set LV '"+o.getIndex()+"' to '"+locals().get(o.getIndex())+"'."); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitATHROW(ATHROW o) { Type t = stack().pop(); stack().clear(); if (t.equals(Type.NULL)) { stack().push(Type.getType("Ljava/lang/NullPointerException;")); } else { stack().push(t); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitBALOAD(BALOAD o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitBASTORE(BASTORE o) { stack().pop(); stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitBIPUSH(BIPUSH o) { stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitCALOAD(CALOAD o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitCASTORE(CASTORE o) { stack().pop(); stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitCHECKCAST(CHECKCAST o) { // It's possibly wrong to do so, but SUN's // ByteCode verifier seems to do (only) this, too. // TODO: One could use a sophisticated analysis here to check // if a type cannot possibly be cated to another and by // so doing predict the ClassCastException at run-time. stack().pop(); stack().push(o.getType(cpg)); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitD2F(D2F o) { stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitD2I(D2I o) { stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitD2L(D2L o) { stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDADD(DADD o) { stack().pop(); stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDALOAD(DALOAD o) { stack().pop(); stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDASTORE(DASTORE o) { stack().pop(); stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDCMPG(DCMPG o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDCMPL(DCMPL o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDCONST(DCONST o) { stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDDIV(DDIV o) { stack().pop(); stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDLOAD(DLOAD o) { stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDMUL(DMUL o) { stack().pop(); stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDNEG(DNEG o) { stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDREM(DREM o) { stack().pop(); stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDRETURN(DRETURN o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDSTORE(DSTORE o) { locals().set(o.getIndex(), stack().pop()); locals().set(o.getIndex() + 1, Type.UNKNOWN); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDSUB(DSUB o) { stack().pop(); stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDUP(DUP o) { Type t = stack().pop(); stack().push(t); stack().push(t); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDUP_X1(DUP_X1 o) { Type w1 = stack().pop(); Type w2 = stack().pop(); stack().push(w1); stack().push(w2); stack().push(w1); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDUP_X2(DUP_X2 o) { Type w1 = stack().pop(); Type w2 = stack().pop(); if (w2.getSize() == 2) { stack().push(w1); stack().push(w2); stack().push(w1); } else { Type w3 = stack().pop(); stack().push(w1); stack().push(w3); stack().push(w2); stack().push(w1); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDUP2(DUP2 o) { Type t = stack().pop(); if (t.getSize() == 2) { stack().push(t); stack().push(t); } else { // t.getSize() is 1 Type u = stack().pop(); stack().push(u); stack().push(t); stack().push(u); stack().push(t); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDUP2_X1(DUP2_X1 o) { Type t = stack().pop(); if (t.getSize() == 2) { Type u = stack().pop(); stack().push(t); stack().push(u); stack().push(t); } else { //t.getSize() is1 Type u = stack().pop(); Type v = stack().pop(); stack().push(u); stack().push(t); stack().push(v); stack().push(u); stack().push(t); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitDUP2_X2(DUP2_X2 o) { Type t = stack().pop(); if (t.getSize() == 2) { Type u = stack().pop(); if (u.getSize() == 2) { stack().push(t); stack().push(u); stack().push(t); } else { Type v = stack().pop(); stack().push(t); stack().push(v); stack().push(u); stack().push(t); } } else { //t.getSize() is 1 Type u = stack().pop(); Type v = stack().pop(); if (v.getSize() == 2) { stack().push(u); stack().push(t); stack().push(v); stack().push(u); stack().push(t); } else { Type w = stack().pop(); stack().push(u); stack().push(t); stack().push(w); stack().push(v); stack().push(u); stack().push(t); } } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitF2D(F2D o) { stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitF2I(F2I o) { stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitF2L(F2L o) { stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFADD(FADD o) { stack().pop(); stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFALOAD(FALOAD o) { stack().pop(); stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFASTORE(FASTORE o) { stack().pop(); stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFCMPG(FCMPG o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFCMPL(FCMPL o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFCONST(FCONST o) { stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFDIV(FDIV o) { stack().pop(); stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFLOAD(FLOAD o) { stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFMUL(FMUL o) { stack().pop(); stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFNEG(FNEG o) { stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFREM(FREM o) { stack().pop(); stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFRETURN(FRETURN o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFSTORE(FSTORE o) { locals().set(o.getIndex(), stack().pop()); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitFSUB(FSUB o) { stack().pop(); stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitGETFIELD(GETFIELD o) { stack().pop(); Type t = o.getFieldType(cpg); if (t.equals(Type.BOOLEAN) || t.equals(Type.CHAR) || t.equals(Type.BYTE) || t.equals(Type.SHORT)) { t = Type.INT; } stack().push(t); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitGETSTATIC(GETSTATIC o) { Type t = o.getFieldType(cpg); if (t.equals(Type.BOOLEAN) || t.equals(Type.CHAR) || t.equals(Type.BYTE) || t.equals(Type.SHORT)) { t = Type.INT; } stack().push(t); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitGOTO(GOTO o) { // no stack changes. } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitGOTO_W(GOTO_W o) { // no stack changes. } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitI2B(I2B o) { stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitI2C(I2C o) { stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitI2D(I2D o) { stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitI2F(I2F o) { stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitI2L(I2L o) { stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitI2S(I2S o) { stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIADD(IADD o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIALOAD(IALOAD o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIAND(IAND o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIASTORE(IASTORE o) { stack().pop(); stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitICONST(ICONST o) { stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIDIV(IDIV o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIF_ACMPEQ(IF_ACMPEQ o) { stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIF_ACMPNE(IF_ACMPNE o) { stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIF_ICMPEQ(IF_ICMPEQ o) { stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIF_ICMPGE(IF_ICMPGE o) { stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIF_ICMPGT(IF_ICMPGT o) { stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIF_ICMPLE(IF_ICMPLE o) { stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIF_ICMPLT(IF_ICMPLT o) { stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIF_ICMPNE(IF_ICMPNE o) { stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIFEQ(IFEQ o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIFGE(IFGE o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIFGT(IFGT o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIFLE(IFLE o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIFLT(IFLT o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIFNE(IFNE o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIFNONNULL(IFNONNULL o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIFNULL(IFNULL o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIINC(IINC o) { // stack is not changed. } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitILOAD(ILOAD o) { stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIMUL(IMUL o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitINEG(INEG o) { stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitINSTANCEOF(INSTANCEOF o) { stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitINVOKEDYNAMIC(INVOKEDYNAMIC o) { for (int i = 0; i < o.getArgumentTypes(cpg).length; i++) { stack().pop(); } // We are sure the invoked method will xRETURN eventually // We simulate xRETURNs functionality here because we // don't really "jump into" and simulate the invoked // method. if (o.getReturnType(cpg) != Type.VOID) { Type t = o.getReturnType(cpg); if (t.equals(Type.BOOLEAN) || t.equals(Type.CHAR) || t.equals(Type.BYTE) || t.equals(Type.SHORT)) { t = Type.INT; } stack().push(t); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitINVOKEINTERFACE(INVOKEINTERFACE o) { stack().pop(); //objectref for (int i = 0; i < o.getArgumentTypes(cpg).length; i++) { stack().pop(); } // We are sure the invoked method will xRETURN eventually // We simulate xRETURNs functionality here because we // don't really "jump into" and simulate the invoked // method. if (o.getReturnType(cpg) != Type.VOID) { Type t = o.getReturnType(cpg); if (t.equals(Type.BOOLEAN) || t.equals(Type.CHAR) || t.equals(Type.BYTE) || t.equals(Type.SHORT)) { t = Type.INT; } stack().push(t); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitINVOKESPECIAL(INVOKESPECIAL o) { if (o.getMethodName(cpg).equals(Constants.CONSTRUCTOR_NAME)) { UninitializedObjectType t = (UninitializedObjectType) stack().peek(o.getArgumentTypes(cpg).length); if (t == Frame._this) { Frame._this = null; } stack().initializeObject(t); locals().initializeObject(t); } stack().pop(); //objectref for (int i = 0; i < o.getArgumentTypes(cpg).length; i++) { stack().pop(); } // We are sure the invoked method will xRETURN eventually // We simulate xRETURNs functionality here because we // don't really "jump into" and simulate the invoked // method. if (o.getReturnType(cpg) != Type.VOID) { Type t = o.getReturnType(cpg); if (t.equals(Type.BOOLEAN) || t.equals(Type.CHAR) || t.equals(Type.BYTE) || t.equals(Type.SHORT)) { t = Type.INT; } stack().push(t); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitINVOKESTATIC(INVOKESTATIC o) { for (int i = 0; i < o.getArgumentTypes(cpg).length; i++) { stack().pop(); } // We are sure the invoked method will xRETURN eventually // We simulate xRETURNs functionality here because we // don't really "jump into" and simulate the invoked // method. if (o.getReturnType(cpg) != Type.VOID) { Type t = o.getReturnType(cpg); if (t.equals(Type.BOOLEAN) || t.equals(Type.CHAR) || t.equals(Type.BYTE) || t.equals(Type.SHORT)) { t = Type.INT; } stack().push(t); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitINVOKEVIRTUAL(INVOKEVIRTUAL o) { stack().pop(); //objectref for (int i = 0; i < o.getArgumentTypes(cpg).length; i++) { stack().pop(); } // We are sure the invoked method will xRETURN eventually // We simulate xRETURNs functionality here because we // don't really "jump into" and simulate the invoked // method. if (o.getReturnType(cpg) != Type.VOID) { Type t = o.getReturnType(cpg); if (t.equals(Type.BOOLEAN) || t.equals(Type.CHAR) || t.equals(Type.BYTE) || t.equals(Type.SHORT)) { t = Type.INT; } stack().push(t); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIOR(IOR o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIREM(IREM o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIRETURN(IRETURN o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitISHL(ISHL o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitISHR(ISHR o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitISTORE(ISTORE o) { locals().set(o.getIndex(), stack().pop()); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitISUB(ISUB o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIUSHR(IUSHR o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitIXOR(IXOR o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitJSR(JSR o) { stack().push(new ReturnaddressType(o.physicalSuccessor())); //System.err.println("TODO-----------:"+o.physicalSuccessor()); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitJSR_W(JSR_W o) { stack().push(new ReturnaddressType(o.physicalSuccessor())); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitL2D(L2D o) { stack().pop(); stack().push(Type.DOUBLE); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitL2F(L2F o) { stack().pop(); stack().push(Type.FLOAT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitL2I(L2I o) { stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLADD(LADD o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLALOAD(LALOAD o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLAND(LAND o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLASTORE(LASTORE o) { stack().pop(); stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLCMP(LCMP o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLCONST(LCONST o) { stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLDC(LDC o) { Constant c = cpg.getConstant(o.getIndex()); if (c instanceof ConstantInteger) { stack().push(Type.INT); } if (c instanceof ConstantFloat) { stack().push(Type.FLOAT); } if (c instanceof ConstantString) { stack().push(Type.STRING); } if (c instanceof ConstantClass) { stack().push(Type.CLASS); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ public void visitLDC_W(LDC_W o) { Constant c = cpg.getConstant(o.getIndex()); if (c instanceof ConstantInteger) { stack().push(Type.INT); } if (c instanceof ConstantFloat) { stack().push(Type.FLOAT); } if (c instanceof ConstantString) { stack().push(Type.STRING); } if (c instanceof ConstantClass) { stack().push(Type.CLASS); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLDC2_W(LDC2_W o) { Constant c = cpg.getConstant(o.getIndex()); if (c instanceof ConstantLong) { stack().push(Type.LONG); } if (c instanceof ConstantDouble) { stack().push(Type.DOUBLE); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLDIV(LDIV o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLLOAD(LLOAD o) { stack().push(locals().get(o.getIndex())); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLMUL(LMUL o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLNEG(LNEG o) { stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLOOKUPSWITCH(LOOKUPSWITCH o) { stack().pop(); //key } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLOR(LOR o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLREM(LREM o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLRETURN(LRETURN o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLSHL(LSHL o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLSHR(LSHR o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLSTORE(LSTORE o) { locals().set(o.getIndex(), stack().pop()); locals().set(o.getIndex() + 1, Type.UNKNOWN); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLSUB(LSUB o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLUSHR(LUSHR o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitLXOR(LXOR o) { stack().pop(); stack().pop(); stack().push(Type.LONG); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitMONITORENTER(MONITORENTER o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitMONITOREXIT(MONITOREXIT o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitMULTIANEWARRAY(MULTIANEWARRAY o) { for (int i = 0; i < o.getDimensions(); i++) { stack().pop(); } stack().push(o.getType(cpg)); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitNEW(NEW o) { stack().push(new UninitializedObjectType((ObjectType) (o.getType(cpg)))); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitNEWARRAY(NEWARRAY o) { stack().pop(); stack().push(o.getType()); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitNOP(NOP o) { } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitPOP(POP o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitPOP2(POP2 o) { Type t = stack().pop(); if (t.getSize() == 1) { stack().pop(); } } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitPUTFIELD(PUTFIELD o) { stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitPUTSTATIC(PUTSTATIC o) { stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitRET(RET o) { // do nothing, return address // is in in the local variables. } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitRETURN(RETURN o) { // do nothing. } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitSALOAD(SALOAD o) { stack().pop(); stack().pop(); stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitSASTORE(SASTORE o) { stack().pop(); stack().pop(); stack().pop(); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitSIPUSH(SIPUSH o) { stack().push(Type.INT); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitSWAP(SWAP o) { Type t = stack().pop(); Type u = stack().pop(); stack().push(t); stack().push(u); } /** Symbolically executes the corresponding Java Virtual Machine instruction. */ @Override public void visitTABLESWITCH(TABLESWITCH o) { stack().pop(); } }