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/*
* 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.bcel.generic;
import org.apache.bcel.classfile.CodeException;
/**
* This class represents an exception handler, i.e., specifies the region where
* a handler is active and an instruction where the actual handling is done.
* pool as parameters. Opposed to the JVM specification the end of the handled
* region is set to be inclusive, i.e. all instructions between start and end
* are protected including the start and end instructions (handles) themselves.
* The end of the region is automatically mapped to be exclusive when calling
* getCodeException(), i.e., there is no difference semantically.
*
* @version $Id$
* @see MethodGen
* @see CodeException
* @see InstructionHandle
*/
public final class CodeExceptionGen implements InstructionTargeter, Cloneable {
private InstructionHandle start_pc;
private InstructionHandle end_pc;
private InstructionHandle handler_pc;
private ObjectType catch_type;
/**
* Add an exception handler, i.e., specify region where a handler is active and an
* instruction where the actual handling is done.
*
* @param start_pc Start of handled region (inclusive)
* @param end_pc End of handled region (inclusive)
* @param handler_pc Where handling is done
* @param catch_type which exception is handled, null for ANY
*/
public CodeExceptionGen(final InstructionHandle start_pc, final InstructionHandle end_pc,
final InstructionHandle handler_pc, final ObjectType catch_type) {
setStartPC(start_pc);
setEndPC(end_pc);
setHandlerPC(handler_pc);
this.catch_type = catch_type;
}
/**
* Get CodeException object.<BR>
*
* This relies on that the instruction list has already been dumped
* to byte code or or that the `setPositions' methods has been
* called for the instruction list.
*
* @param cp constant pool
*/
public CodeException getCodeException( final ConstantPoolGen cp ) {
return new CodeException(start_pc.getPosition(), end_pc.getPosition()
+ end_pc.getInstruction().getLength(), handler_pc.getPosition(),
(catch_type == null) ? 0 : cp.addClass(catch_type));
}
/* Set start of handler
* @param start_pc Start of handled region (inclusive)
*/
public void setStartPC( final InstructionHandle start_pc ) { // TODO could be package-protected?
BranchInstruction.notifyTarget(this.start_pc, start_pc, this);
this.start_pc = start_pc;
}
/* Set end of handler
* @param end_pc End of handled region (inclusive)
*/
public void setEndPC( final InstructionHandle end_pc ) { // TODO could be package-protected?
BranchInstruction.notifyTarget(this.end_pc, end_pc, this);
this.end_pc = end_pc;
}
/* Set handler code
* @param handler_pc Start of handler
*/
public void setHandlerPC( final InstructionHandle handler_pc ) { // TODO could be package-protected?
BranchInstruction.notifyTarget(this.handler_pc, handler_pc, this);
this.handler_pc = handler_pc;
}
/**
* @param old_ih old target, either start or end
* @param new_ih new target
*/
@Override
public void updateTarget( final InstructionHandle old_ih, final InstructionHandle new_ih ) {
boolean targeted = false;
if (start_pc == old_ih) {
targeted = true;
setStartPC(new_ih);
}
if (end_pc == old_ih) {
targeted = true;
setEndPC(new_ih);
}
if (handler_pc == old_ih) {
targeted = true;
setHandlerPC(new_ih);
}
if (!targeted) {
throw new ClassGenException("Not targeting " + old_ih + ", but {" + start_pc + ", "
+ end_pc + ", " + handler_pc + "}");
}
}
/**
* @return true, if ih is target of this handler
*/
@Override
public boolean containsTarget( final InstructionHandle ih ) {
return (start_pc == ih) || (end_pc == ih) || (handler_pc == ih);
}
/** Sets the type of the Exception to catch. Set 'null' for ANY. */
public void setCatchType( final ObjectType catch_type ) {
this.catch_type = catch_type;
}
/** Gets the type of the Exception to catch, 'null' for ANY. */
public ObjectType getCatchType() {
return catch_type;
}
/** @return start of handled region (inclusive)
*/
public InstructionHandle getStartPC() {
return start_pc;
}
/** @return end of handled region (inclusive)
*/
public InstructionHandle getEndPC() {
return end_pc;
}
/** @return start of handler
*/
public InstructionHandle getHandlerPC() {
return handler_pc;
}
@Override
public String toString() {
return "CodeExceptionGen(" + start_pc + ", " + end_pc + ", " + handler_pc + ")";
}
@Override
public Object clone() {
try {
return super.clone();
} catch (final CloneNotSupportedException e) {
throw new Error("Clone Not Supported"); // never happens
}
}
}
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