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ObjectWeb ASM package-renamed to isolate incompatibilities between major versions
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/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2011 INRIA, France Telecom
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.objectweb.asm.commons;
import java.util.Collections;
import java.util.Comparator;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.TryCatchBlockNode;
/**
* A {@link MethodVisitor} adapter to sort the exception handlers. The handlers
* are sorted in a method innermost-to-outermost. This allows the programmer to
* add handlers without worrying about ordering them correctly with respect to
* existing, in-code handlers.
*
* Behavior is only defined for properly-nested handlers. If any "try" blocks
* overlap (something that isn't possible in Java code) then this may not do
* what you want. In fact, this adapter just sorts by the length of the "try"
* block, taking advantage of the fact that a given try block must be larger
* than any block it contains).
*
* @author Adrian Sampson
*/
public class TryCatchBlockSorter extends MethodNode {
public TryCatchBlockSorter(final MethodVisitor mv, final int access,
final String name, final String desc, final String signature,
final String[] exceptions) {
this(Opcodes.ASM5, mv, access, name, desc, signature, exceptions);
}
protected TryCatchBlockSorter(final int api, final MethodVisitor mv,
final int access, final String name, final String desc,
final String signature, final String[] exceptions) {
super(api, access, name, desc, signature, exceptions);
this.mv = mv;
}
@Override
public void visitEnd() {
// Compares TryCatchBlockNodes by the length of their "try" block.
Comparator comp = new Comparator() {
public int compare(TryCatchBlockNode t1, TryCatchBlockNode t2) {
int len1 = blockLength(t1);
int len2 = blockLength(t2);
return len1 - len2;
}
private int blockLength(TryCatchBlockNode block) {
int startidx = instructions.indexOf(block.start);
int endidx = instructions.indexOf(block.end);
return endidx - startidx;
}
};
Collections.sort(tryCatchBlocks, comp);
// Updates the 'target' of each try catch block annotation.
for (int i = 0; i < tryCatchBlocks.size(); ++i) {
tryCatchBlocks.get(i).updateIndex(i);
}
if (mv != null) {
accept(mv);
}
}
}