/*******************************************************************************
- * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Common Public License v0.5
+ * are made available under the terms of the Common Public License v1.0
* which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/cpl-v05.html
+ * http://www.eclipse.org/legal/cpl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
- ******************************************************************************/
+ *******************************************************************************/
package net.sourceforge.phpdt.internal.compiler.ast;
-import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
-import net.sourceforge.phpdt.internal.compiler.impl.*;
-import net.sourceforge.phpdt.internal.compiler.flow.*;
-import net.sourceforge.phpdt.internal.compiler.codegen.*;
-import net.sourceforge.phpdt.internal.compiler.lookup.*;
+import net.sourceforge.phpdt.internal.compiler.ASTVisitor;
+import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
+import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
+import net.sourceforge.phpdt.internal.compiler.lookup.BindingIds;
+import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
+import net.sourceforge.phpdt.internal.compiler.lookup.InvocationSite;
+import net.sourceforge.phpdt.internal.compiler.lookup.MethodBinding;
+import net.sourceforge.phpdt.internal.compiler.lookup.ProblemMethodBinding;
+import net.sourceforge.phpdt.internal.compiler.lookup.ReferenceBinding;
+import net.sourceforge.phpdt.internal.compiler.lookup.SourceTypeBinding;
+import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;
public class MessageSend extends Expression implements InvocationSite {
- public Expression receiver ;
- public char[] selector ;
- public Expression[] arguments ;
+ public Expression receiver;
+
+ public char[] selector;
+
+ public Expression[] arguments;
+
public MethodBinding binding, codegenBinding;
- public long nameSourcePosition ; //(start<<32)+end
+ public long nameSourcePosition; // (start<<32)+end
MethodBinding syntheticAccessor;
public TypeBinding receiverType, qualifyingType;
-
-public MessageSend() {
-
-}
-public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {
- flowInfo = receiver.analyseCode(currentScope, flowContext, flowInfo, !binding.isStatic()).unconditionalInits();
- if (arguments != null) {
- int length = arguments.length;
- for (int i = 0; i < length; i++) {
- flowInfo = arguments[i].analyseCode(currentScope, flowContext, flowInfo).unconditionalInits();
- }
- }
- ReferenceBinding[] thrownExceptions;
- if ((thrownExceptions = binding.thrownExceptions) != NoExceptions) {
- // must verify that exceptions potentially thrown by this expression are caught in the method
- flowContext.checkExceptionHandlers(thrownExceptions, this, flowInfo, currentScope);
- }
- // if invoking through an enclosing instance, then must perform the field generation -- only if reachable
- manageEnclosingInstanceAccessIfNecessary(currentScope);
- manageSyntheticAccessIfNecessary(currentScope);
- return flowInfo;
-}
-/**
- * MessageSend code generation
- *
- * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
- * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
- * @param valueRequired boolean
- */
-public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
-
- int pc = codeStream.position;
-
- // generate receiver/enclosing instance access
- boolean isStatic = codegenBinding.isStatic();
- // outer access ?
- if (!isStatic && ((bits & DepthMASK) != 0) && (receiver == ThisReference.ThisImplicit)){
- // outer method can be reached through emulation if implicit access
- Object[] path = currentScope.getExactEmulationPath(currentScope.enclosingSourceType().enclosingTypeAt((bits & DepthMASK) >> DepthSHIFT));
- if (path == null) {
- // emulation was not possible (should not happen per construction)
- currentScope.problemReporter().needImplementation();
- } else {
- codeStream.generateOuterAccess(path, this, currentScope);
- }
- } else {
- receiver.generateCode(currentScope, codeStream, !isStatic);
- }
- // generate arguments
- if (arguments != null){
- for (int i = 0, max = arguments.length; i < max; i++){
- arguments[i].generateCode(currentScope, codeStream, true);
- }
+ public MessageSend() {
+
}
- // actual message invocation
- if (syntheticAccessor == null){
- if (isStatic){
- codeStream.invokestatic(codegenBinding);
- } else {
- if( (receiver.isSuper()) || codegenBinding.isPrivate()){
- codeStream.invokespecial(codegenBinding);
- } else {
- if (codegenBinding.declaringClass.isInterface()){
- codeStream.invokeinterface(codegenBinding);
- } else {
- codeStream.invokevirtual(codegenBinding);
- }
+
+ public FlowInfo analyseCode(BlockScope currentScope,
+ FlowContext flowContext, FlowInfo flowInfo) {
+
+ flowInfo = receiver.analyseCode(currentScope, flowContext, flowInfo,
+ !binding.isStatic()).unconditionalInits();
+ if (arguments != null) {
+ int length = arguments.length;
+ for (int i = 0; i < length; i++) {
+ flowInfo = arguments[i].analyseCode(currentScope, flowContext,
+ flowInfo).unconditionalInits();
}
}
- } else {
- codeStream.invokestatic(syntheticAccessor);
- }
- // operation on the returned value
- if (valueRequired){
- // implicit conversion if necessary
- codeStream.generateImplicitConversion(implicitConversion);
- } else {
- // pop return value if any
- switch(binding.returnType.id){
- case T_long :
- case T_double :
- codeStream.pop2();
- break;
- case T_void :
- break;
- default:
- codeStream.pop();
+ ReferenceBinding[] thrownExceptions;
+ if ((thrownExceptions = binding.thrownExceptions) != NoExceptions) {
+ // must verify that exceptions potentially thrown by this expression
+ // are caught in the method
+ flowContext.checkExceptionHandlers(thrownExceptions, this,
+ flowInfo, currentScope);
}
+ manageSyntheticAccessIfNecessary(currentScope);
+ return flowInfo;
}
- codeStream.recordPositionsFrom(pc, (int)(this.nameSourcePosition >>> 32)); // highlight selector
-}
-public boolean isSuperAccess() {
- return receiver.isSuper();
-}
-public boolean isTypeAccess() {
- return receiver != null && receiver.isTypeReference();
-}
-public void manageEnclosingInstanceAccessIfNecessary(BlockScope currentScope) {
- if (((bits & DepthMASK) != 0) && !binding.isStatic() && (receiver == ThisReference.ThisImplicit)) {
- ReferenceBinding compatibleType = currentScope.enclosingSourceType();
- // the declaringClass of the target binding must be compatible with the enclosing
- // type at <depth> levels outside
- for (int i = 0, depth = (bits & DepthMASK) >> DepthSHIFT; i < depth; i++) {
- compatibleType = compatibleType.enclosingType();
- }
- currentScope.emulateOuterAccess((SourceTypeBinding) compatibleType, false); // request cascade of accesses
+
+ /**
+ * MessageSend code generation
+ *
+ * @param currentScope
+ * net.sourceforge.phpdt.internal.compiler.lookup.BlockScope
+ * @param codeStream
+ * net.sourceforge.phpdt.internal.compiler.codegen.CodeStream
+ * @param valueRequired
+ * boolean
+ */
+ // public void generateCode(BlockScope currentScope, CodeStream codeStream,
+ // boolean valueRequired) {
+ //
+ // int pc = codeStream.position;
+ //
+ // // generate receiver/enclosing instance access
+ // boolean isStatic = codegenBinding.isStatic();
+ // // outer access ?
+ // if (!isStatic && ((bits & DepthMASK) != 0) && receiver.isImplicitThis()){
+ // // outer method can be reached through emulation if implicit access
+ // ReferenceBinding targetType =
+ // currentScope.enclosingSourceType().enclosingTypeAt((bits & DepthMASK) >>
+ // DepthSHIFT);
+ // Object[] path = currentScope.getEmulationPath(targetType, true /*only
+ // exact match*/, false/*consider enclosing arg*/);
+ // codeStream.generateOuterAccess(path, this, targetType, currentScope);
+ // } else {
+ // receiver.generateCode(currentScope, codeStream, !isStatic);
+ // }
+ // // generate arguments
+ // if (arguments != null){
+ // for (int i = 0, max = arguments.length; i < max; i++){
+ // arguments[i].generateCode(currentScope, codeStream, true);
+ // }
+ // }
+ // // actual message invocation
+ // if (syntheticAccessor == null){
+ // if (isStatic){
+ // codeStream.invokestatic(codegenBinding);
+ // } else {
+ // if( (receiver.isSuper()) || codegenBinding.isPrivate()){
+ // codeStream.invokespecial(codegenBinding);
+ // } else {
+ // if (codegenBinding.declaringClass.isInterface()){
+ // codeStream.invokeinterface(codegenBinding);
+ // } else {
+ // codeStream.invokevirtual(codegenBinding);
+ // }
+ // }
+ // }
+ // } else {
+ // codeStream.invokestatic(syntheticAccessor);
+ // }
+ // // operation on the returned value
+ // if (valueRequired){
+ // // implicit conversion if necessary
+ // codeStream.generateImplicitConversion(implicitConversion);
+ // } else {
+ // // pop return value if any
+ // switch(binding.returnType.id){
+ // case T_long :
+ // case T_double :
+ // codeStream.pop2();
+ // break;
+ // case T_void :
+ // break;
+ // default:
+ // codeStream.pop();
+ // }
+ // }
+ // codeStream.recordPositionsFrom(pc, (int)(this.nameSourcePosition >>>
+ // 32)); // highlight selector
+ // }
+ public boolean isSuperAccess() {
+ return receiver.isSuper();
}
-}
-public void manageSyntheticAccessIfNecessary(BlockScope currentScope){
- if (binding.isPrivate()){
+ public boolean isTypeAccess() {
+ return receiver != null && receiver.isTypeReference();
+ }
- // depth is set for both implicit and explicit access (see MethodBinding#canBeSeenBy)
- if (currentScope.enclosingSourceType() != binding.declaringClass){
-
- syntheticAccessor = ((SourceTypeBinding)binding.declaringClass).addSyntheticMethod(binding);
- currentScope.problemReporter().needToEmulateMethodAccess(binding, this);
- return;
- }
+ public void manageSyntheticAccessIfNecessary(BlockScope currentScope) {
- } else if (receiver instanceof QualifiedSuperReference){ // qualified super
+ if (binding.isPrivate()) {
- // qualified super need emulation always
- SourceTypeBinding destinationType = (SourceTypeBinding)(((QualifiedSuperReference)receiver).currentCompatibleType);
- syntheticAccessor = destinationType.addSyntheticMethod(binding);
- currentScope.problemReporter().needToEmulateMethodAccess(binding, this);
- return;
+ // depth is set for both implicit and explicit access (see
+ // MethodBinding#canBeSeenBy)
+ if (currentScope.enclosingSourceType() != binding.declaringClass) {
- } else if (binding.isProtected()){
+ syntheticAccessor = ((SourceTypeBinding) binding.declaringClass)
+ .addSyntheticMethod(binding, isSuperAccess());
+ currentScope.problemReporter().needToEmulateMethodAccess(
+ binding, this);
+ return;
+ }
- SourceTypeBinding enclosingSourceType;
- if (((bits & DepthMASK) != 0)
- && binding.declaringClass.getPackage()
- != (enclosingSourceType = currentScope.enclosingSourceType()).getPackage()){
+ } else if (receiver instanceof QualifiedSuperReference) { // qualified
+ // super
- SourceTypeBinding currentCompatibleType = (SourceTypeBinding)enclosingSourceType.enclosingTypeAt((bits & DepthMASK) >> DepthSHIFT);
- syntheticAccessor = currentCompatibleType.addSyntheticMethod(binding);
- currentScope.problemReporter().needToEmulateMethodAccess(binding, this);
+ // qualified super need emulation always
+ SourceTypeBinding destinationType = (SourceTypeBinding) (((QualifiedSuperReference) receiver).currentCompatibleType);
+ syntheticAccessor = destinationType.addSyntheticMethod(binding,
+ isSuperAccess());
+ currentScope.problemReporter().needToEmulateMethodAccess(binding,
+ this);
return;
+
+ } else if (binding.isProtected()) {
+
+ SourceTypeBinding enclosingSourceType;
+ if (((bits & DepthMASK) != 0)
+ && binding.declaringClass.getPackage() != (enclosingSourceType = currentScope
+ .enclosingSourceType()).getPackage()) {
+
+ SourceTypeBinding currentCompatibleType = (SourceTypeBinding) enclosingSourceType
+ .enclosingTypeAt((bits & DepthMASK) >> DepthSHIFT);
+ syntheticAccessor = currentCompatibleType.addSyntheticMethod(
+ binding, isSuperAccess());
+ currentScope.problemReporter().needToEmulateMethodAccess(
+ binding, this);
+ return;
+ }
}
+ // if the binding declaring class is not visible, need special action
+ // for runtime compatibility on 1.2 VMs : change the declaring class of
+ // the binding
+ // NOTE: from target 1.2 on, method's declaring class is touched if any
+ // different from receiver type
+ // and not from Object or implicit static method call.
+ // if (binding.declaringClass != this.qualifyingType
+ // && !this.qualifyingType.isArrayType()
+ // && ((currentScope.environment().options.targetJDK >=
+ // CompilerOptions.JDK1_2
+ // && (!receiver.isImplicitThis() || !binding.isStatic())
+ // && binding.declaringClass.id != T_Object) // no change for Object
+ // methods
+ // || !binding.declaringClass.canBeSeenBy(currentScope))) {
+ //
+ // this.codegenBinding =
+ // currentScope.enclosingSourceType().getUpdatedMethodBinding(binding,
+ // (ReferenceBinding) this.qualifyingType);
+ // }
}
- // if the binding declaring class is not visible, need special action
- // for runtime compatibility on 1.2 VMs : change the declaring class of the binding
- // NOTE: from 1.4 on, method's declaring class is touched if any different from receiver type
- // and not from Object or implicit static method call.
- if (binding.declaringClass != this.qualifyingType
- && !this.qualifyingType.isArrayType()
- && ((currentScope.environment().options.complianceLevel >= CompilerOptions.JDK1_4
- && (receiver != ThisReference.ThisImplicit || !binding.isStatic())
- && binding.declaringClass.id != T_Object) // no change for Object methods
- || !binding.declaringClass.canBeSeenBy(currentScope))) {
-
- this.codegenBinding = currentScope.enclosingSourceType().getUpdatedMethodBinding(binding, (ReferenceBinding) this.qualifyingType);
- }
-}
-public TypeBinding resolveType(BlockScope scope) {
- // Answer the signature return type
- // Base type promotion
-
- constant = NotAConstant;
- this.qualifyingType = this.receiverType = receiver.resolveType(scope);
-
- // will check for null after args are resolved
- TypeBinding[] argumentTypes = NoParameters;
- if (arguments != null) {
- boolean argHasError = false; // typeChecks all arguments
- int length = arguments.length;
- argumentTypes = new TypeBinding[length];
- for (int i = 0; i < length; i++){
- if ((argumentTypes[i] = arguments[i].resolveType(scope)) == null){
- argHasError = true;
+ public StringBuffer printExpression(int indent, StringBuffer output) {
+
+ if (!receiver.isImplicitThis())
+ receiver.printExpression(0, output).append('.');
+ output.append(selector).append('('); //$NON-NLS-1$
+ if (arguments != null) {
+ for (int i = 0; i < arguments.length; i++) {
+ if (i > 0)
+ output.append(", "); //$NON-NLS-1$
+ arguments[i].printExpression(0, output);
}
}
- if (argHasError){
- MethodBinding closestMethod = null;
- if(receiverType instanceof ReferenceBinding) {
- // record any selector match, for clients who may still need hint about possible method match
- this.codegenBinding = this.binding = scope.findMethod((ReferenceBinding)receiverType, selector, new TypeBinding[]{}, this);
- }
- return null;
- }
+ return output.append(')');
}
- if (this.receiverType == null)
- return null;
- // base type cannot receive any message
- if (this.receiverType.isBaseType()) {
- scope.problemReporter().errorNoMethodFor(this, this.receiverType, argumentTypes);
- return null;
- }
+ public TypeBinding resolveType(BlockScope scope) {
+ // Answer the signature return type
+ // Base type promotion
+
+ constant = NotAConstant;
+ this.qualifyingType = this.receiverType = receiver.resolveType(scope);
- this.codegenBinding = this.binding =
- receiver == ThisReference.ThisImplicit
- ? scope.getImplicitMethod(selector, argumentTypes, this)
- : scope.getMethod(this.receiverType, selector, argumentTypes, this);
- if (!binding.isValidBinding()) {
- if (binding.declaringClass == null) {
- if (this.receiverType instanceof ReferenceBinding) {
- binding.declaringClass = (ReferenceBinding) this.receiverType;
- } else { // really bad error ....
- scope.problemReporter().errorNoMethodFor(this, this.receiverType, argumentTypes);
+ // will check for null after args are resolved
+ TypeBinding[] argumentTypes = NoParameters;
+ if (arguments != null) {
+ boolean argHasError = false; // typeChecks all arguments
+ int length = arguments.length;
+ argumentTypes = new TypeBinding[length];
+ for (int i = 0; i < length; i++) {
+ if ((argumentTypes[i] = arguments[i].resolveType(scope)) == null) {
+ argHasError = true;
+ }
+ }
+ if (argHasError) {
+ if (receiverType instanceof ReferenceBinding) {
+ // record any selector match, for clients who may still need
+ // hint about possible method match
+ this.codegenBinding = this.binding = scope.findMethod(
+ (ReferenceBinding) receiverType, selector,
+ new TypeBinding[] {}, this);
+ }
return null;
}
}
- scope.problemReporter().invalidMethod(this, binding);
- // record the closest match, for clients who may still need hint about possible method match
- if (binding.problemId() == ProblemReasons.NotFound){
- this.codegenBinding = this.binding = ((ProblemMethodBinding)binding).closestMatch;
+ if (this.receiverType == null)
+ return null;
+
+ // base type cannot receive any message
+ if (this.receiverType.isBaseType()) {
+ scope.problemReporter().errorNoMethodFor(this, this.receiverType,
+ argumentTypes);
+ return null;
}
- return null;
- }
- if (!binding.isStatic()) {
- // the "receiver" must not be a type, i.e. a NameReference that the TC has bound to a Type
- if (receiver instanceof NameReference) {
- if ((((NameReference) receiver).bits & BindingIds.TYPE) != 0) {
+
+ this.codegenBinding = this.binding = receiver.isImplicitThis() ? scope
+ .getImplicitMethod(selector, argumentTypes, this) : scope
+ .getMethod(this.receiverType, selector, argumentTypes, this);
+ if (!binding.isValidBinding()) {
+ if (binding.declaringClass == null) {
+ if (this.receiverType instanceof ReferenceBinding) {
+ binding.declaringClass = (ReferenceBinding) this.receiverType;
+ } else {
+ scope.problemReporter().errorNoMethodFor(this,
+ this.receiverType, argumentTypes);
+ return null;
+ }
+ }
+ scope.problemReporter().invalidMethod(this, binding);
+ // record the closest match, for clients who may still need hint
+ // about possible method match
+ if (binding instanceof ProblemMethodBinding) {
+ MethodBinding closestMatch = ((ProblemMethodBinding) binding).closestMatch;
+ if (closestMatch != null)
+ this.codegenBinding = this.binding = closestMatch;
+ }
+ return binding == null ? null : binding.returnType;
+ }
+ if (!binding.isStatic()) {
+ // the "receiver" must not be a type, in other words, a
+ // NameReference that the TC has bound to a Type
+ if (receiver instanceof NameReference
+ && (((NameReference) receiver).bits & BindingIds.TYPE) != 0) {
scope.problemReporter().mustUseAStaticMethod(this, binding);
- return null;
+ }
+ } else {
+ // static message invoked through receiver? legal but unoptimal
+ // (optional warning).
+ if (!(receiver.isImplicitThis() || receiver.isSuper() || (receiver instanceof NameReference && (((NameReference) receiver).bits & BindingIds.TYPE) != 0))) {
+ scope.problemReporter().unnecessaryReceiverForStaticMethod(
+ this, binding);
}
}
- }
- if (arguments != null)
- for (int i = 0; i < arguments.length; i++)
- arguments[i].implicitWidening(binding.parameters[i], argumentTypes[i]);
-
- //-------message send that are known to fail at compile time-----------
- if (binding.isAbstract()) {
- if (receiver.isSuper()) {
- scope.problemReporter().cannotDireclyInvokeAbstractMethod(this, binding);
- return null;
+ if (arguments != null)
+ for (int i = 0; i < arguments.length; i++)
+ arguments[i].implicitWidening(binding.parameters[i],
+ argumentTypes[i]);
+
+ // -------message send that are known to fail at compile time-----------
+ if (binding.isAbstract()) {
+ if (receiver.isSuper()) {
+ scope.problemReporter().cannotDireclyInvokeAbstractMethod(this,
+ binding);
+ }
+ // abstract private methods cannot occur nor abstract
+ // static............
}
- // abstract private methods cannot occur nor abstract static............
+ if (isMethodUseDeprecated(binding, scope))
+ scope.problemReporter().deprecatedMethod(binding, this);
+
+ return this.resolvedType = binding.returnType;
}
- if (isMethodUseDeprecated(binding, scope))
- scope.problemReporter().deprecatedMethod(binding, this);
- return binding.returnType;
-}
-public void setActualReceiverType(ReferenceBinding receiverType) {
- this.qualifyingType = receiverType;
-}
-public void setDepth(int depth) {
- if (depth > 0) {
+ public void setActualReceiverType(ReferenceBinding receiverType) {
+ this.qualifyingType = receiverType;
+ }
+
+ public void setDepth(int depth) {
bits &= ~DepthMASK; // flush previous depth if any
- bits |= (depth & 0xFF) << DepthSHIFT; // encoded on 8 bits
+ if (depth > 0) {
+ bits |= (depth & 0xFF) << DepthSHIFT; // encoded on 8 bits
+ }
}
-}
-public void setFieldIndex(int depth) {
- // ignore for here
-}
-public String toStringExpression(){
-
- String s = ""; //$NON-NLS-1$
- if (receiver != ThisReference.ThisImplicit)
- s = s + receiver.toStringExpression()+"."; //$NON-NLS-1$
- s = s + new String(selector) + "(" ; //$NON-NLS-1$
- if (arguments != null)
- for (int i = 0; i < arguments.length ; i ++)
- { s = s + arguments[i].toStringExpression();
- if ( i != arguments.length -1 ) s = s + " , " ;};; //$NON-NLS-1$
- s =s + ")" ; //$NON-NLS-1$
- return s;
-}
+ public void setFieldIndex(int depth) {
+ // ignore for here
+ }
-public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope blockScope) {
- if (visitor.visit(this, blockScope)) {
- receiver.traverse(visitor, blockScope);
- if (arguments != null) {
- int argumentsLength = arguments.length;
- for (int i = 0; i < argumentsLength; i++)
- arguments[i].traverse(visitor, blockScope);
+ public String toStringExpression() {
+
+ String s = ""; //$NON-NLS-1$
+ if (!receiver.isImplicitThis())
+ s = s + receiver.toStringExpression() + "."; //$NON-NLS-1$
+ s = s + new String(selector) + "("; //$NON-NLS-1$
+ if (arguments != null)
+ for (int i = 0; i < arguments.length; i++) {
+ s = s + arguments[i].toStringExpression();
+ if (i != arguments.length - 1)
+ s = s + " , ";};; //$NON-NLS-1$
+ s = s + ")"; //$NON-NLS-1$
+ return s;
+ }
+
+ public void traverse(ASTVisitor visitor, BlockScope blockScope) {
+ if (visitor.visit(this, blockScope)) {
+ receiver.traverse(visitor, blockScope);
+ if (arguments != null) {
+ int argumentsLength = arguments.length;
+ for (int i = 0; i < argumentsLength; i++)
+ arguments[i].traverse(visitor, blockScope);
+ }
}
+ visitor.endVisit(this, blockScope);
}
- visitor.endVisit(this, blockScope);
-}
}
git://git.phpeclipse.com / phpeclipse.git / blobdiff