| // 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.apache.tapestry5.internal.plastic.asm.commons; |
| |
| import java.util.Collections; |
| import java.util.Comparator; |
| import org.apache.tapestry5.internal.plastic.asm.MethodVisitor; |
| import org.apache.tapestry5.internal.plastic.asm.Opcodes; |
| import org.apache.tapestry5.internal.plastic.asm.tree.MethodNode; |
| import org.apache.tapestry5.internal.plastic.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. |
| * |
| * <p>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 { |
| |
| /** |
| * Constructs a new {@link TryCatchBlockSorter}. |
| * |
| * @param methodVisitor the method visitor to which this visitor must delegate method calls. May |
| * be {@literal null}. |
| * @param access the method's access flags (see {@link Opcodes}). This parameter also indicates if |
| * the method is synthetic and/or deprecated. |
| * @param name the method's name. |
| * @param descriptor the method's descriptor (see {@link org.apache.tapestry5.internal.plastic.asm.Type}). |
| * @param signature the method's signature. May be {@literal null} if the method parameters, |
| * return type and exceptions do not use generic types. |
| * @param exceptions the internal names of the method's exception classes (see {@link |
| * org.apache.tapestry5.internal.plastic.asm.Type#getInternalName()}). May be {@literal null}. |
| */ |
| public TryCatchBlockSorter( |
| final MethodVisitor methodVisitor, |
| final int access, |
| final String name, |
| final String descriptor, |
| final String signature, |
| final String[] exceptions) { |
| this( |
| /* latest api = */ Opcodes.ASM8, |
| methodVisitor, |
| access, |
| name, |
| descriptor, |
| signature, |
| exceptions); |
| if (getClass() != TryCatchBlockSorter.class) { |
| throw new IllegalStateException(); |
| } |
| } |
| |
| protected TryCatchBlockSorter( |
| final int api, |
| final MethodVisitor methodVisitor, |
| final int access, |
| final String name, |
| final String descriptor, |
| final String signature, |
| final String[] exceptions) { |
| super(api, access, name, descriptor, signature, exceptions); |
| this.mv = methodVisitor; |
| } |
| |
| @Override |
| public void visitEnd() { |
| // Sort the TryCatchBlockNode elements by the length of their "try" block. |
| Collections.sort( |
| tryCatchBlocks, |
| new Comparator<TryCatchBlockNode>() { |
| |
| @Override |
| public int compare( |
| final TryCatchBlockNode tryCatchBlockNode1, |
| final TryCatchBlockNode tryCatchBlockNode2) { |
| return blockLength(tryCatchBlockNode1) - blockLength(tryCatchBlockNode2); |
| } |
| |
| private int blockLength(final TryCatchBlockNode tryCatchBlockNode) { |
| int startIndex = instructions.indexOf(tryCatchBlockNode.start); |
| int endIndex = instructions.indexOf(tryCatchBlockNode.end); |
| return endIndex - startIndex; |
| } |
| }); |
| // Update 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); |
| } |
| } |
| } |