/* * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * This source code is provided to illustrate the usage of a given feature * or technique and has been deliberately simplified. Additional steps * required for a production-quality application, such as security checks, * input validation and proper error handling, might not be present in * this sample code. */ package com.sun.tools.example.debug.expr; import com.sun.jdi.*; import java.util.*; abstract class LValue { // The JDI Value object for this LValue. Once we have this Value, // we have to remember it since after we return the LValue object // to the ExpressionParser, it might decide that it needs // the 'toString' value for the LValue in which case it will // call getMassagedValue to get this toString value. At that // point, we don't want to call JDI a 2nd time to get the Value // for the LValue. This is especially wrong when the LValue // represents a member function. We would end up calling it // a 2nd time. // // Unfortunately, there are several levels of calls to // get/set values in this file. To minimize confusion, // jdiValue is set/tested at the lowest level - right // next to the actual calls to JDI methods to get/set the // value in the debuggee. protected Value jdiValue; abstract Value getValue() throws InvocationException, IncompatibleThreadStateException, InvalidTypeException, ClassNotLoadedException, ParseException; abstract void setValue0(Value value) throws ParseException, InvalidTypeException, ClassNotLoadedException; abstract void invokeWith(List<Value> arguments) throws ParseException; void setValue(Value value) throws ParseException { try { setValue0(value); } catch (InvalidTypeException exc) { throw new ParseException( "Attempt to set value of incorrect type" + exc); } catch (ClassNotLoadedException exc) { throw new ParseException( "Attempt to set value before " + exc.className() + " was loaded" + exc); } } void setValue(LValue lval) throws ParseException { setValue(lval.interiorGetValue()); } LValue memberLValue(ExpressionParser.GetFrame frameGetter, String fieldName) throws ParseException { try { return memberLValue(fieldName, frameGetter.get().thread()); } catch (IncompatibleThreadStateException exc) { throw new ParseException("Thread not suspended"); } } LValue memberLValue(String fieldName, ThreadReference thread) throws ParseException { Value val = interiorGetValue(); if ((val instanceof ArrayReference) && "length".equals(fieldName)){ return new LValueArrayLength((ArrayReference)val); } return new LValueInstanceMember(val, fieldName, thread); } // Return the Value for this LValue that would be used to concatenate // to a String. IE, if it is an Object, call toString in the debuggee. Value getMassagedValue(ExpressionParser.GetFrame frameGetter) throws ParseException { Value vv = interiorGetValue(); // If vv is an ObjectReference, then we have to // do the implicit call to toString(). if (vv instanceof ObjectReference && !(vv instanceof StringReference) && !(vv instanceof ArrayReference)) { StackFrame frame; try { frame = frameGetter.get(); } catch (IncompatibleThreadStateException exc) { throw new ParseException("Thread not suspended"); } ThreadReference thread = frame.thread(); LValue toStringMember = memberLValue("toString", thread); toStringMember.invokeWith(new ArrayList<Value>()); return toStringMember.interiorGetValue(); } return vv; } Value interiorGetValue() throws ParseException { Value value; try { value = getValue(); } catch (InvocationException e) { throw new ParseException("Unable to complete expression. Exception " + e.exception() + " thrown"); } catch (IncompatibleThreadStateException itse) { throw new ParseException("Unable to complete expression. Thread " + "not suspended for method invoke"); } catch (InvalidTypeException ite) { throw new ParseException("Unable to complete expression. Method " + "argument type mismatch"); } catch (ClassNotLoadedException tnle) { throw new ParseException("Unable to complete expression. Method " + "argument type " + tnle.className() + " not yet loaded"); } return value; } LValue arrayElementLValue(LValue lval) throws ParseException { Value indexValue = lval.interiorGetValue(); int index; if ( (indexValue instanceof IntegerValue) || (indexValue instanceof ShortValue) || (indexValue instanceof ByteValue) || (indexValue instanceof CharValue) ) { index = ((PrimitiveValue)indexValue).intValue(); } else { throw new ParseException("Array index must be a integer type"); } return new LValueArrayElement(interiorGetValue(), index); } @Override public String toString() { try { return interiorGetValue().toString(); } catch (ParseException e) { return "<Parse Exception>"; } } static final int STATIC = 0; static final int INSTANCE = 1; static Field fieldByName(ReferenceType refType, String name, int kind) { /* * TO DO: Note that this currently fails to find superclass * or implemented interface fields. This is due to a temporary * limititation of RefType.fieldByName. Once that method is * fixed, superclass fields will be found. */ Field field = refType.fieldByName(name); if (field != null) { boolean isStatic = field.isStatic(); if (((kind == STATIC) && !isStatic) || ((kind == INSTANCE) && isStatic)) { field = null; } } /*** System.err.println("fieldByName: " + refType.name() + " " + name + " " + kind + " " + (field != null)); ***/ return field; } static List<Method> methodsByName(ReferenceType refType, String name, int kind) { List<Method> list = refType.methodsByName(name); Iterator<Method> iter = list.iterator(); while (iter.hasNext()) { Method method = iter.next(); boolean isStatic = method.isStatic(); if (((kind == STATIC) && !isStatic) || ((kind == INSTANCE) && isStatic)) { iter.remove(); } } return list; } static List<String> primitiveTypeNames = new ArrayList<String>(); static { primitiveTypeNames.add("boolean"); primitiveTypeNames.add("byte"); primitiveTypeNames.add("char"); primitiveTypeNames.add("short"); primitiveTypeNames.add("int"); primitiveTypeNames.add("long"); primitiveTypeNames.add("float"); primitiveTypeNames.add("double"); } static final int SAME = 0; static final int ASSIGNABLE = 1; static final int DIFFERENT = 2; /* * Return SAME, DIFFERENT or ASSIGNABLE. * SAME means each arg type is the same as type of the corr. arg. * ASSIGNABLE means that not all the pairs are the same, but * for those that aren't, at least the argType is assignable * from the type of the argument value. * DIFFERENT means that in at least one pair, the * argType is not assignable from the type of the argument value. * IE, one is an Apple and the other is an Orange. */ static int argumentsMatch(List<Type> argTypes, List<Value> arguments) { if (argTypes.size() != arguments.size()) { return DIFFERENT; } Iterator<Type> typeIter = argTypes.iterator(); Iterator<Value> valIter = arguments.iterator(); int result = SAME; // If any pair aren't the same, change the // result to ASSIGNABLE. If any pair aren't // assignable, return DIFFERENT while (typeIter.hasNext()) { Type argType = typeIter.next(); Value value = valIter.next(); if (value == null) { // Null values can be passed to any non-primitive argument if (primitiveTypeNames.contains(argType.name())) { return DIFFERENT; } // Else, we will assume that a null value // exactly matches an object type. } if (!value.type().equals(argType)) { if (isAssignableTo(value.type(), argType)) { result = ASSIGNABLE; } else { return DIFFERENT; } } } return result; } // These is...AssignableTo methods are based on similar code in the JDI // implementations of ClassType, ArrayType, and InterfaceType static boolean isComponentAssignable(Type fromType, Type toType) { if (fromType instanceof PrimitiveType) { // Assignment of primitive arrays requires identical // component types. return fromType.equals(toType); } if (toType instanceof PrimitiveType) { return false; } // Assignment of object arrays requires availability // of widening conversion of component types return isAssignableTo(fromType, toType); } static boolean isArrayAssignableTo(ArrayType fromType, Type toType) { if (toType instanceof ArrayType) { try { Type toComponentType = ((ArrayType)toType).componentType(); return isComponentAssignable(fromType.componentType(), toComponentType); } catch (ClassNotLoadedException e) { // One or both component types has not yet been // loaded => can't assign return false; } } if (toType instanceof InterfaceType) { // Only valid InterfaceType assignee is Cloneable return toType.name().equals("java.lang.Cloneable"); } // Only valid ClassType assignee is Object return toType.name().equals("java.lang.Object"); } static boolean isAssignableTo(Type fromType, Type toType) { if (fromType.equals(toType)) { return true; } // If one is boolean, so must be the other. if (fromType instanceof BooleanType) { if (toType instanceof BooleanType) { return true; } return false; } if (toType instanceof BooleanType) { return false; } // Other primitive types are intermixable only with each other. if (fromType instanceof PrimitiveType) { if (toType instanceof PrimitiveType) { return true; } return false; } if (toType instanceof PrimitiveType) { return false; } // neither one is primitive. if (fromType instanceof ArrayType) { return isArrayAssignableTo((ArrayType)fromType, toType); } List<InterfaceType> interfaces; if (fromType instanceof ClassType) { ClassType superclazz = ((ClassType)fromType).superclass(); if ((superclazz != null) && isAssignableTo(superclazz, toType)) { return true; } interfaces = ((ClassType)fromType).interfaces(); } else { // fromType must be an InterfaceType interfaces = ((InterfaceType)fromType).superinterfaces(); } for (InterfaceType interfaze : interfaces) { if (isAssignableTo(interfaze, toType)) { return true; } } return false; } static Method resolveOverload(List<Method> overloads, List<Value> arguments) throws ParseException { // If there is only one method to call, we'll just choose // that without looking at the args. If they aren't right // the invoke will return a better error message than we // could generate here. if (overloads.size() == 1) { return overloads.get(0); } // Resolving overloads is beyond the scope of this exercise. // So, we will look for a method that matches exactly the // types of the arguments. If we can't find one, then // if there is exactly one method whose param types are assignable // from the arg types, we will use that. Otherwise, // it is an error. We won't guess which of multiple possible // methods to call. And, since casts aren't implemented, // the user can't use them to pick a particular overload to call. // IE, the user is out of luck in this case. Method retVal = null; int assignableCount = 0; for (Method mm : overloads) { List<Type> argTypes; try { argTypes = mm.argumentTypes(); } catch (ClassNotLoadedException ee) { // This probably won't happen for the // method that we are really supposed to // call. continue; } int compare = argumentsMatch(argTypes, arguments); if (compare == SAME) { return mm; } if (compare == DIFFERENT) { continue; } // Else, it is assignable. Remember it. retVal = mm; assignableCount++; } // At this point, we didn't find an exact match, // but we found one for which the args are assignable. // if (retVal != null) { if (assignableCount == 1) { return retVal; } throw new ParseException("Arguments match multiple methods"); } throw new ParseException("Arguments match no method"); } private static class LValueLocal extends LValue { final StackFrame frame; final LocalVariable var; LValueLocal(StackFrame frame, LocalVariable var) { this.frame = frame; this.var = var; } @Override Value getValue() { if (jdiValue == null) { jdiValue = frame.getValue(var); } return jdiValue; } @Override void setValue0(Value val) throws InvalidTypeException, ClassNotLoadedException { frame.setValue(var, val); jdiValue = val; } @Override void invokeWith(List<Value> arguments) throws ParseException { throw new ParseException(var.name() + " is not a method"); } } private static class LValueInstanceMember extends LValue { final ObjectReference obj; final ThreadReference thread; final Field matchingField; final List<Method> overloads; Method matchingMethod = null; List<Value> methodArguments = null; LValueInstanceMember(Value value, String memberName, ThreadReference thread) throws ParseException { if (!(value instanceof ObjectReference)) { throw new ParseException( "Cannot access field of primitive type: " + value); } this.obj = (ObjectReference)value; this.thread = thread; ReferenceType refType = obj.referenceType(); /* * Can't tell yet whether this LValue will be accessed as a * field or method, so we keep track of all the possibilities */ matchingField = LValue.fieldByName(refType, memberName, LValue.INSTANCE); overloads = LValue.methodsByName(refType, memberName, LValue.INSTANCE); if ((matchingField == null) && overloads.size() == 0) { throw new ParseException("No instance field or method with the name " + memberName + " in " + refType.name()); } } @Override Value getValue() throws InvocationException, InvalidTypeException, ClassNotLoadedException, IncompatibleThreadStateException, ParseException { if (jdiValue != null) { return jdiValue; } if (matchingMethod == null) { if (matchingField == null) { throw new ParseException("No such field in " + obj.referenceType().name()); } return jdiValue = obj.getValue(matchingField); } else { return jdiValue = obj.invokeMethod(thread, matchingMethod, methodArguments, 0); } } @Override void setValue0(Value val) throws ParseException, InvalidTypeException, ClassNotLoadedException { if (matchingMethod != null) { throw new ParseException("Cannot assign to a method invocation"); } obj.setValue(matchingField, val); jdiValue = val; } @Override void invokeWith(List<Value> arguments) throws ParseException { if (matchingMethod != null) { throw new ParseException("Invalid consecutive invocations"); } methodArguments = arguments; matchingMethod = LValue.resolveOverload(overloads, arguments); } } private static class LValueStaticMember extends LValue { final ReferenceType refType; final ThreadReference thread; final Field matchingField; final List<Method> overloads; Method matchingMethod = null; List<Value> methodArguments = null; LValueStaticMember(ReferenceType refType, String memberName, ThreadReference thread) throws ParseException { this.refType = refType; this.thread = thread; /* * Can't tell yet whether this LValue will be accessed as a * field or method, so we keep track of all the possibilities */ matchingField = LValue.fieldByName(refType, memberName, LValue.STATIC); overloads = LValue.methodsByName(refType, memberName, LValue.STATIC); if ((matchingField == null) && overloads.size() == 0) { throw new ParseException("No static field or method with the name " + memberName + " in " + refType.name()); } } @Override Value getValue() throws InvocationException, InvalidTypeException, ClassNotLoadedException, IncompatibleThreadStateException, ParseException { if (jdiValue != null) { return jdiValue; } if (matchingMethod == null) { return jdiValue = refType.getValue(matchingField); } else if (refType instanceof ClassType) { ClassType clazz = (ClassType)refType; return jdiValue = clazz.invokeMethod(thread, matchingMethod, methodArguments, 0); } else { throw new InvalidTypeException("Cannot invoke static method on " + refType.name()); } } @Override void setValue0(Value val) throws ParseException, InvalidTypeException, ClassNotLoadedException { if (matchingMethod != null) { throw new ParseException("Cannot assign to a method invocation"); } if (!(refType instanceof ClassType)) { throw new ParseException( "Cannot set interface field: " + refType); } ((ClassType)refType).setValue(matchingField, val); jdiValue = val; } @Override void invokeWith(List<Value> arguments) throws ParseException { if (matchingMethod != null) { throw new ParseException("Invalid consecutive invocations"); } methodArguments = arguments; matchingMethod = LValue.resolveOverload(overloads, arguments); } } private static class LValueArrayLength extends LValue { /* * Since one can code "int myLen = myArray.length;", * one might expect that these JDI calls would get a Value * object for the length of an array in the debugee: * Field xxx = ArrayType.fieldByName("length") * Value lenVal= ArrayReference.getValue(xxx) * * However, this doesn't work because the array length isn't * really stored as a field, and can't be accessed as such * via JDI. Instead, the arrayRef.length() method has to be * used. */ final ArrayReference arrayRef; LValueArrayLength (ArrayReference value) { this.arrayRef = value; } @Override Value getValue() { if (jdiValue == null) { jdiValue = arrayRef.virtualMachine().mirrorOf(arrayRef.length()); } return jdiValue; } @Override void setValue0(Value value) throws ParseException { throw new ParseException("Cannot set constant: " + value); } @Override void invokeWith(List<Value> arguments) throws ParseException { throw new ParseException("Array element is not a method"); } } private static class LValueArrayElement extends LValue { final ArrayReference array; final int index; LValueArrayElement(Value value, int index) throws ParseException { if (!(value instanceof ArrayReference)) { throw new ParseException( "Must be array type: " + value); } this.array = (ArrayReference)value; this.index = index; } @Override Value getValue() { if (jdiValue == null) { jdiValue = array.getValue(index); } return jdiValue; } @Override void setValue0(Value val) throws InvalidTypeException, ClassNotLoadedException { array.setValue(index, val); jdiValue = val; } @Override void invokeWith(List<Value> arguments) throws ParseException { throw new ParseException("Array element is not a method"); } } private static class LValueConstant extends LValue { final Value value; LValueConstant(Value value) { this.value = value; } @Override Value getValue() { if (jdiValue == null) { jdiValue = value; } return jdiValue; } @Override void setValue0(Value val) throws ParseException { throw new ParseException("Cannot set constant: " + value); } @Override void invokeWith(List<Value> arguments) throws ParseException { throw new ParseException("Constant is not a method"); } } static LValue make(VirtualMachine vm, boolean val) { return new LValueConstant(vm.mirrorOf(val)); } static LValue make(VirtualMachine vm, byte val) { return new LValueConstant(vm.mirrorOf(val)); } static LValue make(VirtualMachine vm, char val) { return new LValueConstant(vm.mirrorOf(val)); } static LValue make(VirtualMachine vm, short val) { return new LValueConstant(vm.mirrorOf(val)); } static LValue make(VirtualMachine vm, int val) { return new LValueConstant(vm.mirrorOf(val)); } static LValue make(VirtualMachine vm, long val) { return new LValueConstant(vm.mirrorOf(val)); } static LValue make(VirtualMachine vm, float val) { return new LValueConstant(vm.mirrorOf(val)); } static LValue make(VirtualMachine vm, double val) { return new LValueConstant(vm.mirrorOf(val)); } static LValue make(VirtualMachine vm, String val) throws ParseException { return new LValueConstant(vm.mirrorOf(val)); } static LValue makeBoolean(VirtualMachine vm, Token token) { return make(vm, token.image.charAt(0) == 't'); } static LValue makeCharacter(VirtualMachine vm, Token token) { return make(vm, token.image.charAt(1)); } static LValue makeFloat(VirtualMachine vm, Token token) { return make(vm, Float.valueOf(token.image).floatValue()); } static LValue makeDouble(VirtualMachine vm, Token token) { return make(vm, Double.valueOf(token.image).doubleValue()); } static LValue makeInteger(VirtualMachine vm, Token token) { return make(vm, Integer.parseInt(token.image)); } static LValue makeShort(VirtualMachine vm, Token token) { return make(vm, Short.parseShort(token.image)); } static LValue makeLong(VirtualMachine vm, Token token) { return make(vm, Long.parseLong(token.image)); } static LValue makeByte(VirtualMachine vm, Token token) { return make(vm, Byte.parseByte(token.image)); } static LValue makeString(VirtualMachine vm, Token token) throws ParseException { int len = token.image.length(); return make(vm, token.image.substring(1,len-1)); } static LValue makeNull(VirtualMachine vm, Token token) throws ParseException { return new LValueConstant(null); } static LValue makeThisObject(VirtualMachine vm, ExpressionParser.GetFrame frameGetter, Token token) throws ParseException { if (frameGetter == null) { throw new ParseException("No current thread"); } else { try { StackFrame frame = frameGetter.get(); ObjectReference thisObject = frame.thisObject(); if (thisObject==null) { throw new ParseException( "No 'this'. In native or static method"); } else { return new LValueConstant(thisObject); } } catch (IncompatibleThreadStateException exc) { throw new ParseException("Thread not suspended"); } } } static LValue makeNewObject(VirtualMachine vm, ExpressionParser.GetFrame frameGetter, String className, List<Value> arguments) throws ParseException { List<ReferenceType> classes = vm.classesByName(className); if (classes.size() == 0) { throw new ParseException("No class named: " + className); } if (classes.size() > 1) { throw new ParseException("More than one class named: " + className); } ReferenceType refType = classes.get(0); if (!(refType instanceof ClassType)) { throw new ParseException("Cannot create instance of interface " + className); } ClassType classType = (ClassType)refType; List<Method> methods = new ArrayList<Method>(classType.methods()); // writable Iterator<Method> iter = methods.iterator(); while (iter.hasNext()) { Method method = iter.next(); if (!method.isConstructor()) { iter.remove(); } } Method constructor = LValue.resolveOverload(methods, arguments); ObjectReference newObject; try { ThreadReference thread = frameGetter.get().thread(); newObject = classType.newInstance(thread, constructor, arguments, 0); } catch (InvocationException ie) { throw new ParseException("Exception in " + className + " constructor: " + ie.exception().referenceType().name()); } catch (IncompatibleThreadStateException exc) { throw new ParseException("Thread not suspended"); } catch (Exception e) { /* * TO DO: Better error handling */ throw new ParseException("Unable to create " + className + " instance"); } return new LValueConstant(newObject); } private static LValue nFields(LValue lval, StringTokenizer izer, ThreadReference thread) throws ParseException { if (!izer.hasMoreTokens()) { return lval; } else { return nFields(lval.memberLValue(izer.nextToken(), thread), izer, thread); } } static LValue makeName(VirtualMachine vm, ExpressionParser.GetFrame frameGetter, String name) throws ParseException { StringTokenizer izer = new StringTokenizer(name, "."); String first = izer.nextToken(); // check local variables if (frameGetter != null) { try { StackFrame frame = frameGetter.get(); ThreadReference thread = frame.thread(); LocalVariable var; try { var = frame.visibleVariableByName(first); } catch (AbsentInformationException e) { var = null; } if (var != null) { return nFields(new LValueLocal(frame, var), izer, thread); } else { ObjectReference thisObject = frame.thisObject(); if (thisObject != null) { // check if it is a field of 'this' LValue thisLValue = new LValueConstant(thisObject); LValue fv; try { fv = thisLValue.memberLValue(first, thread); } catch (ParseException exc) { fv = null; } if (fv != null) { return nFields(fv, izer, thread); } } } // check for class name while (izer.hasMoreTokens()) { List<ReferenceType> classes = vm.classesByName(first); if (classes.size() > 0) { if (classes.size() > 1) { throw new ParseException("More than one class named: " + first); } else { ReferenceType refType = classes.get(0); LValue lval = new LValueStaticMember(refType, izer.nextToken(), thread); return nFields(lval, izer, thread); } } first = first + '.' + izer.nextToken(); } } catch (IncompatibleThreadStateException exc) { throw new ParseException("Thread not suspended"); } } throw new ParseException("Name unknown: " + name); } static String stringValue(LValue lval, ExpressionParser.GetFrame frameGetter ) throws ParseException { Value val = lval.getMassagedValue(frameGetter); if (val == null) { return "null"; } if (val instanceof StringReference) { return ((StringReference)val).value(); } return val.toString(); // is this correct in all cases? } static LValue booleanOperation(VirtualMachine vm, Token token, LValue rightL, LValue leftL) throws ParseException { String op = token.image; Value right = rightL.interiorGetValue(); Value left = leftL.interiorGetValue(); if ( !(right instanceof PrimitiveValue) || !(left instanceof PrimitiveValue) ) { if (op.equals("==")) { return make(vm, right.equals(left)); } else if (op.equals("!=")) { return make(vm, !right.equals(left)); } else { throw new ParseException("Operands or '" + op + "' must be primitive"); } } // can compare any numeric doubles double rr = ((PrimitiveValue)right).doubleValue(); double ll = ((PrimitiveValue)left).doubleValue(); boolean res; if (op.equals("<")) { res = rr < ll; } else if (op.equals(">")) { res = rr > ll; } else if (op.equals("<=")) { res = rr <= ll; } else if (op.equals(">=")) { res = rr >= ll; } else if (op.equals("==")) { res = rr == ll; } else if (op.equals("!=")) { res = rr != ll; } else { throw new ParseException("Unknown operation: " + op); } return make(vm, res); } static LValue operation(VirtualMachine vm, Token token, LValue rightL, LValue leftL, ExpressionParser.GetFrame frameGetter ) throws ParseException { String op = token.image; Value right = rightL.interiorGetValue(); Value left = leftL.interiorGetValue(); if ((right instanceof StringReference) || (left instanceof StringReference)) { if (op.equals("+")) { // If one is an ObjectRef, we will need to invoke // toString on it, so we need the thread. return make(vm, stringValue(rightL, frameGetter) + stringValue(leftL, frameGetter)); } } if ((right instanceof ObjectReference) || (left instanceof ObjectReference)) { if (op.equals("==")) { return make(vm, right.equals(left)); } else if (op.equals("!=")) { return make(vm, !right.equals(left)); } else { throw new ParseException("Invalid operation '" + op + "' on an Object"); } } if ((right instanceof BooleanValue) || (left instanceof BooleanValue)) { throw new ParseException("Invalid operation '" + op + "' on a Boolean"); } // from here on, we know it is a integer kind of type PrimitiveValue primRight = (PrimitiveValue)right; PrimitiveValue primLeft = (PrimitiveValue)left; if ((primRight instanceof DoubleValue) || (primLeft instanceof DoubleValue)) { double rr = primRight.doubleValue(); double ll = primLeft.doubleValue(); double res; if (op.equals("+")) { res = rr + ll; } else if (op.equals("-")) { res = rr - ll; } else if (op.equals("*")) { res = rr * ll; } else if (op.equals("/")) { res = rr / ll; } else { throw new ParseException("Unknown operation: " + op); } return make(vm, res); } if ((primRight instanceof FloatValue) || (primLeft instanceof FloatValue)) { float rr = primRight.floatValue(); float ll = primLeft.floatValue(); float res; if (op.equals("+")) { res = rr + ll; } else if (op.equals("-")) { res = rr - ll; } else if (op.equals("*")) { res = rr * ll; } else if (op.equals("/")) { res = rr / ll; } else { throw new ParseException("Unknown operation: " + op); } return make(vm, res); } if ((primRight instanceof LongValue) || (primLeft instanceof LongValue)) { long rr = primRight.longValue(); long ll = primLeft.longValue(); long res; if (op.equals("+")) { res = rr + ll; } else if (op.equals("-")) { res = rr - ll; } else if (op.equals("*")) { res = rr * ll; } else if (op.equals("/")) { res = rr / ll; } else { throw new ParseException("Unknown operation: " + op); } return make(vm, res); } else { int rr = primRight.intValue(); int ll = primLeft.intValue(); int res; if (op.equals("+")) { res = rr + ll; } else if (op.equals("-")) { res = rr - ll; } else if (op.equals("*")) { res = rr * ll; } else if (op.equals("/")) { res = rr / ll; } else { throw new ParseException("Unknown operation: " + op); } return make(vm, res); } } }