/*
 * 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.
See Also:
MethodGen
CodeException
InstructionHandle/**
 * 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.
 *
 * @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.
Params:
start_pc – Start of handled region (inclusive)
end_pc – End of handled region (inclusive)
handler_pc – Where handling is done
catch_type – which exception is handled, null for ANY/**
     * 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.

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.
Params:
cp – constant pool/**
     * 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;
    }


    
Params:
old_ih – old target, either start or end
new_ih – new target/**
     * @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 + "}");
        }
    }


    
Returns:
true, if ih is target of this handler/**
     * @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. /** 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. /** Gets the type of the Exception to catch, 'null' for ANY. */
    public ObjectType getCatchType() {
        return catch_type;
    }


    
Returns:
start of handled region (inclusive)/** @return start of handled region (inclusive)
     */
    public InstructionHandle getStartPC() {
        return start_pc;
    }


    
Returns:
end of handled region (inclusive)/** @return end of handled region (inclusive)
     */
    public InstructionHandle getEndPC() {
        return end_pc;
    }


    
Returns:
start of handler/** @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
        }
    }
}