ASM: a very small and fast Java bytecode manipulation framework
Copyright (c) 2000-2011 INRIA, France Telecom
All rights reserved.
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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
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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.tree;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.Handle;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;

A node that represents a method.
Author:
Eric Bruneton/**
 * A node that represents a method.
 * 
 * @author Eric Bruneton
 */
public class MethodNode extends MethodVisitor {

    
The method's access flags (see Opcodes). This field also indicates if the method is synthetic and/or deprecated. /**
     * The method's access flags (see {@link Opcodes}). This field also
     * indicates if the method is synthetic and/or deprecated.
     */
    public int access;

    
The method's name.
/**
     * The method's name.
     */
    public String name;

    
The method's descriptor (see Type). /**
     * The method's descriptor (see {@link Type}).
     */
    public String desc;

    
The method's signature. May be null.
/**
     * The method's signature. May be <tt>null</tt>.
     */
    public String signature;

    
The internal names of the method's exception classes (see getInternalName). This list is a list of String objects. /**
     * The internal names of the method's exception classes (see
     * {@link Type#getInternalName() getInternalName}). This list is a list of
     * {@link String} objects.
     */
    public List<String> exceptions;

    
The runtime visible annotations of this method. This list is a list of AnnotationNode objects. May be null.
@associates
org.objectweb.asm.tree.AnnotationNode
@label
visible/**
     * The runtime visible annotations of this method. This list is a list of
     * {@link AnnotationNode} objects. May be <tt>null</tt>.
     * 
     * @associates org.objectweb.asm.tree.AnnotationNode
     * @label visible
     */
    public List<AnnotationNode> visibleAnnotations;

    
The runtime invisible annotations of this method. This list is a list of AnnotationNode objects. May be null.
@associates
org.objectweb.asm.tree.AnnotationNode
@label
invisible/**
     * The runtime invisible annotations of this method. This list is a list of
     * {@link AnnotationNode} objects. May be <tt>null</tt>.
     * 
     * @associates org.objectweb.asm.tree.AnnotationNode
     * @label invisible
     */
    public List<AnnotationNode> invisibleAnnotations;

    
The non standard attributes of this method. This list is a list of Attribute objects. May be null.
@associates
org.objectweb.asm.Attribute/**
     * The non standard attributes of this method. This list is a list of
     * {@link Attribute} objects. May be <tt>null</tt>.
     * 
     * @associates org.objectweb.asm.Attribute
     */
    public List<Attribute> attrs;

    
The default value of this annotation interface method. This field must be a Byte, Boolean, Character, Short, Integer, Long, Float, Double, String or Type, or an two elements String array (for enumeration values), a AnnotationNode, or a List of values of one of the preceding types. May be null.
/**
     * The default value of this annotation interface method. This field must be
     * a {@link Byte}, {@link Boolean}, {@link Character}, {@link Short},
     * {@link Integer}, {@link Long}, {@link Float}, {@link Double},
     * {@link String} or {@link Type}, or an two elements String array (for
     * enumeration values), a {@link AnnotationNode}, or a {@link List} of
     * values of one of the preceding types. May be <tt>null</tt>.
     */
    public Object annotationDefault;

    
The runtime visible parameter annotations of this method. These lists are lists of AnnotationNode objects. May be null.
@associates
org.objectweb.asm.tree.AnnotationNode
@label
invisible parameters/**
     * The runtime visible parameter annotations of this method. These lists are
     * lists of {@link AnnotationNode} objects. May be <tt>null</tt>.
     * 
     * @associates org.objectweb.asm.tree.AnnotationNode
     * @label invisible parameters
     */
    public List<AnnotationNode>[] visibleParameterAnnotations;

    
The runtime invisible parameter annotations of this method. These lists are lists of AnnotationNode objects. May be null.
@associates
org.objectweb.asm.tree.AnnotationNode
@label
visible parameters/**
     * The runtime invisible parameter annotations of this method. These lists
     * are lists of {@link AnnotationNode} objects. May be <tt>null</tt>.
     * 
     * @associates org.objectweb.asm.tree.AnnotationNode
     * @label visible parameters
     */
    public List<AnnotationNode>[] invisibleParameterAnnotations;

    
The instructions of this method. This list is a list of AbstractInsnNode objects. 
@associates
org.objectweb.asm.tree.AbstractInsnNode
@label
instructions/**
     * The instructions of this method. This list is a list of
     * {@link AbstractInsnNode} objects.
     * 
     * @associates org.objectweb.asm.tree.AbstractInsnNode
     * @label instructions
     */
    public InsnList instructions;

    
The try catch blocks of this method. This list is a list of TryCatchBlockNode objects. 
@associates
org.objectweb.asm.tree.TryCatchBlockNode/**
     * The try catch blocks of this method. This list is a list of
     * {@link TryCatchBlockNode} objects.
     * 
     * @associates org.objectweb.asm.tree.TryCatchBlockNode
     */
    public List<TryCatchBlockNode> tryCatchBlocks;

    
The maximum stack size of this method.
/**
     * The maximum stack size of this method.
     */
    public int maxStack;

    
The maximum number of local variables of this method.
/**
     * The maximum number of local variables of this method.
     */
    public int maxLocals;

    
The local variables of this method. This list is a list of LocalVariableNode objects. May be null
@associates
org.objectweb.asm.tree.LocalVariableNode/**
     * The local variables of this method. This list is a list of
     * {@link LocalVariableNode} objects. May be <tt>null</tt>
     * 
     * @associates org.objectweb.asm.tree.LocalVariableNode
     */
    public List<LocalVariableNode> localVariables;

    
If the accept method has been called on this object.
/**
     * If the accept method has been called on this object.
     */
    private boolean visited;

    
Constructs an uninitialized MethodNode. Subclasses must not
use this constructor. Instead, they must use the MethodNode(int) version. /**
     * Constructs an uninitialized {@link MethodNode}. <i>Subclasses must not
     * use this constructor</i>. Instead, they must use the
     * {@link #MethodNode(int)} version.
     */
    public MethodNode() {
        this(Opcodes.ASM4);
    }

    
Constructs an uninitialized MethodNode. 
Params:
api –  the ASM API version implemented by this visitor. Must be one of Opcodes.ASM4./**
     * Constructs an uninitialized {@link MethodNode}.
     * 
     * @param api
     *            the ASM API version implemented by this visitor. Must be one
     *            of {@link Opcodes#ASM4}.
     */
    public MethodNode(final int api) {
        super(api);
        this.instructions = new InsnList();
    }

    
Constructs a new MethodNode. Subclasses must not use this
constructor. Instead, they must use the MethodNode(int, int, String, String, String, String[]) version. 
Params:
access –  the method's access flags (see Opcodes). This parameter also indicates if the method is synthetic and/or deprecated.
name – 
           the method's name.
desc –  the method's descriptor (see Type).
signature – 
           the method's signature. May be null.
exceptions –  the internal names of the method's exception classes (see getInternalName). May be null./**
     * Constructs a new {@link MethodNode}. <i>Subclasses must not use this
     * constructor</i>. Instead, they must use the
     * {@link #MethodNode(int, int, String, String, String, String[])} version.
     * 
     * @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 desc
     *            the method's descriptor (see {@link Type}).
     * @param signature
     *            the method's signature. May be <tt>null</tt>.
     * @param exceptions
     *            the internal names of the method's exception classes (see
     *            {@link Type#getInternalName() getInternalName}). May be
     *            <tt>null</tt>.
     */
    public MethodNode(final int access, final String name, final String desc,
            final String signature, final String[] exceptions) {
        this(Opcodes.ASM4, access, name, desc, signature, exceptions);
    }

    
Constructs a new MethodNode. 
Params:
api –  the ASM API version implemented by this visitor. Must be one of Opcodes.ASM4.
access –  the method's access flags (see Opcodes). This parameter also indicates if the method is synthetic and/or deprecated.
name – 
           the method's name.
desc –  the method's descriptor (see Type).
signature – 
           the method's signature. May be null.
exceptions –  the internal names of the method's exception classes (see getInternalName). May be null./**
     * Constructs a new {@link MethodNode}.
     * 
     * @param api
     *            the ASM API version implemented by this visitor. Must be one
     *            of {@link Opcodes#ASM4}.
     * @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 desc
     *            the method's descriptor (see {@link Type}).
     * @param signature
     *            the method's signature. May be <tt>null</tt>.
     * @param exceptions
     *            the internal names of the method's exception classes (see
     *            {@link Type#getInternalName() getInternalName}). May be
     *            <tt>null</tt>.
     */
    public MethodNode(final int api, final int access, final String name,
            final String desc, final String signature, final String[] exceptions) {
        super(api);
        this.access = access;
        this.name = name;
        this.desc = desc;
        this.signature = signature;
        this.exceptions = new ArrayList<String>(exceptions == null ? 0
                : exceptions.length);
        boolean isAbstract = (access & Opcodes.ACC_ABSTRACT) != 0;
        if (!isAbstract) {
            this.localVariables = new ArrayList<LocalVariableNode>(5);
        }
        this.tryCatchBlocks = new ArrayList<TryCatchBlockNode>();
        if (exceptions != null) {
            this.exceptions.addAll(Arrays.asList(exceptions));
        }
        this.instructions = new InsnList();
    }

    // ------------------------------------------------------------------------
    // Implementation of the MethodVisitor abstract class
    // ------------------------------------------------------------------------

    @Override
    public AnnotationVisitor visitAnnotationDefault() {
        return new AnnotationNode(new ArrayList<Object>(0) {
            @Override
            public boolean add(final Object o) {
                annotationDefault = o;
                return super.add(o);
            }
        });
    }

    @Override
    public AnnotationVisitor visitAnnotation(final String desc,
            final boolean visible) {
        AnnotationNode an = new AnnotationNode(desc);
        if (visible) {
            if (visibleAnnotations == null) {
                visibleAnnotations = new ArrayList<AnnotationNode>(1);
            }
            visibleAnnotations.add(an);
        } else {
            if (invisibleAnnotations == null) {
                invisibleAnnotations = new ArrayList<AnnotationNode>(1);
            }
            invisibleAnnotations.add(an);
        }
        return an;
    }

    @Override
    public AnnotationVisitor visitParameterAnnotation(final int parameter,
            final String desc, final boolean visible) {
        AnnotationNode an = new AnnotationNode(desc);
        if (visible) {
            if (visibleParameterAnnotations == null) {
                int params = Type.getArgumentTypes(this.desc).length;
                visibleParameterAnnotations = (List<AnnotationNode>[]) new List<?>[params];
            }
            if (visibleParameterAnnotations[parameter] == null) {
                visibleParameterAnnotations[parameter] = new ArrayList<AnnotationNode>(
                        1);
            }
            visibleParameterAnnotations[parameter].add(an);
        } else {
            if (invisibleParameterAnnotations == null) {
                int params = Type.getArgumentTypes(this.desc).length;
                invisibleParameterAnnotations = (List<AnnotationNode>[]) new List<?>[params];
            }
            if (invisibleParameterAnnotations[parameter] == null) {
                invisibleParameterAnnotations[parameter] = new ArrayList<AnnotationNode>(
                        1);
            }
            invisibleParameterAnnotations[parameter].add(an);
        }
        return an;
    }

    @Override
    public void visitAttribute(final Attribute attr) {
        if (attrs == null) {
            attrs = new ArrayList<Attribute>(1);
        }
        attrs.add(attr);
    }

    @Override
    public void visitCode() {
    }

    @Override
    public void visitFrame(final int type, final int nLocal,
            final Object[] local, final int nStack, final Object[] stack) {
        instructions.add(new FrameNode(type, nLocal, local == null ? null
                : getLabelNodes(local), nStack, stack == null ? null
                : getLabelNodes(stack)));
    }

    @Override
    public void visitInsn(final int opcode) {
        instructions.add(new InsnNode(opcode));
    }

    @Override
    public void visitIntInsn(final int opcode, final int operand) {
        instructions.add(new IntInsnNode(opcode, operand));
    }

    @Override
    public void visitVarInsn(final int opcode, final int var) {
        instructions.add(new VarInsnNode(opcode, var));
    }

    @Override
    public void visitTypeInsn(final int opcode, final String type) {
        instructions.add(new TypeInsnNode(opcode, type));
    }

    @Override
    public void visitFieldInsn(final int opcode, final String owner,
            final String name, final String desc) {
        instructions.add(new FieldInsnNode(opcode, owner, name, desc));
    }

    @Override
    public void visitMethodInsn(final int opcode, final String owner,
            final String name, final String desc) {
        instructions.add(new MethodInsnNode(opcode, owner, name, desc));
    }

    @Override
    public void visitInvokeDynamicInsn(String name, String desc, Handle bsm,
            Object... bsmArgs) {
        instructions.add(new InvokeDynamicInsnNode(name, desc, bsm, bsmArgs));
    }

    @Override
    public void visitJumpInsn(final int opcode, final Label label) {
        instructions.add(new JumpInsnNode(opcode, getLabelNode(label)));
    }

    @Override
    public void visitLabel(final Label label) {
        instructions.add(getLabelNode(label));
    }

    @Override
    public void visitLdcInsn(final Object cst) {
        instructions.add(new LdcInsnNode(cst));
    }

    @Override
    public void visitIincInsn(final int var, final int increment) {
        instructions.add(new IincInsnNode(var, increment));
    }

    @Override
    public void visitTableSwitchInsn(final int min, final int max,
            final Label dflt, final Label... labels) {
        instructions.add(new TableSwitchInsnNode(min, max, getLabelNode(dflt),
                getLabelNodes(labels)));
    }

    @Override
    public void visitLookupSwitchInsn(final Label dflt, final int[] keys,
            final Label[] labels) {
        instructions.add(new LookupSwitchInsnNode(getLabelNode(dflt), keys,
                getLabelNodes(labels)));
    }

    @Override
    public void visitMultiANewArrayInsn(final String desc, final int dims) {
        instructions.add(new MultiANewArrayInsnNode(desc, dims));
    }

    @Override
    public void visitTryCatchBlock(final Label start, final Label end,
            final Label handler, final String type) {
        tryCatchBlocks.add(new TryCatchBlockNode(getLabelNode(start),
                getLabelNode(end), getLabelNode(handler), type));
    }

    @Override
    public void visitLocalVariable(final String name, final String desc,
            final String signature, final Label start, final Label end,
            final int index) {
        localVariables.add(new LocalVariableNode(name, desc, signature,
                getLabelNode(start), getLabelNode(end), index));
    }

    @Override
    public void visitLineNumber(final int line, final Label start) {
        instructions.add(new LineNumberNode(line, getLabelNode(start)));
    }

    @Override
    public void visitMaxs(final int maxStack, final int maxLocals) {
        this.maxStack = maxStack;
        this.maxLocals = maxLocals;
    }

    @Override
    public void visitEnd() {
    }

    
Returns the LabelNode corresponding to the given Label. Creates a new LabelNode if necessary. The default implementation of this method uses the Label.info field to store associations between labels and label nodes. 
Params:
l – 
           a Label.
Returns:
the LabelNode corresponding to l./**
     * Returns the LabelNode corresponding to the given Label. Creates a new
     * LabelNode if necessary. The default implementation of this method uses
     * the {@link Label#info} field to store associations between labels and
     * label nodes.
     * 
     * @param l
     *            a Label.
     * @return the LabelNode corresponding to l.
     */
    protected LabelNode getLabelNode(final Label l) {
        if (!(l.info instanceof LabelNode)) {
            l.info = new LabelNode();
        }
        return (LabelNode) l.info;
    }

    private LabelNode[] getLabelNodes(final Label[] l) {
        LabelNode[] nodes = new LabelNode[l.length];
        for (int i = 0; i < l.length; ++i) {
            nodes[i] = getLabelNode(l[i]);
        }
        return nodes;
    }

    private Object[] getLabelNodes(final Object[] objs) {
        Object[] nodes = new Object[objs.length];
        for (int i = 0; i < objs.length; ++i) {
            Object o = objs[i];
            if (o instanceof Label) {
                o = getLabelNode((Label) o);
            }
            nodes[i] = o;
        }
        return nodes;
    }

    // ------------------------------------------------------------------------
    // Accept method
    // ------------------------------------------------------------------------

    
Checks that this method node is compatible with the given ASM API
version. This methods checks that this node, and all its nodes
recursively, do not contain elements that were introduced in more recent
versions of the ASM API than the given version.
Params:
api –  an ASM API version. Must be one of Opcodes.ASM4./**
     * Checks that this method node is compatible with the given ASM API
     * version. This methods checks that this node, and all its nodes
     * recursively, do not contain elements that were introduced in more recent
     * versions of the ASM API than the given version.
     * 
     * @param api
     *            an ASM API version. Must be one of {@link Opcodes#ASM4}.
     */
    public void check(final int api) {
        // nothing to do
    }

    
Makes the given class visitor visit this method.
Params:
cv – 
           a class visitor./**
     * Makes the given class visitor visit this method.
     * 
     * @param cv
     *            a class visitor.
     */
    public void accept(final ClassVisitor cv) {
        String[] exceptions = new String[this.exceptions.size()];
        this.exceptions.toArray(exceptions);
        MethodVisitor mv = cv.visitMethod(access, name, desc, signature,
                exceptions);
        if (mv != null) {
            accept(mv);
        }
    }

    
Makes the given method visitor visit this method.
Params:
mv – 
           a method visitor./**
     * Makes the given method visitor visit this method.
     * 
     * @param mv
     *            a method visitor.
     */
    public void accept(final MethodVisitor mv) {
        // visits the method attributes
        int i, j, n;
        if (annotationDefault != null) {
            AnnotationVisitor av = mv.visitAnnotationDefault();
            AnnotationNode.accept(av, null, annotationDefault);
            if (av != null) {
                av.visitEnd();
            }
        }
        n = visibleAnnotations == null ? 0 : visibleAnnotations.size();
        for (i = 0; i < n; ++i) {
            AnnotationNode an = visibleAnnotations.get(i);
            an.accept(mv.visitAnnotation(an.desc, true));
        }
        n = invisibleAnnotations == null ? 0 : invisibleAnnotations.size();
        for (i = 0; i < n; ++i) {
            AnnotationNode an = invisibleAnnotations.get(i);
            an.accept(mv.visitAnnotation(an.desc, false));
        }
        n = visibleParameterAnnotations == null ? 0
                : visibleParameterAnnotations.length;
        for (i = 0; i < n; ++i) {
            List<?> l = visibleParameterAnnotations[i];
            if (l == null) {
                continue;
            }
            for (j = 0; j < l.size(); ++j) {
                AnnotationNode an = (AnnotationNode) l.get(j);
                an.accept(mv.visitParameterAnnotation(i, an.desc, true));
            }
        }
        n = invisibleParameterAnnotations == null ? 0
                : invisibleParameterAnnotations.length;
        for (i = 0; i < n; ++i) {
            List<?> l = invisibleParameterAnnotations[i];
            if (l == null) {
                continue;
            }
            for (j = 0; j < l.size(); ++j) {
                AnnotationNode an = (AnnotationNode) l.get(j);
                an.accept(mv.visitParameterAnnotation(i, an.desc, false));
            }
        }
        if (visited) {
            instructions.resetLabels();
        }
        n = attrs == null ? 0 : attrs.size();
        for (i = 0; i < n; ++i) {
            mv.visitAttribute(attrs.get(i));
        }
        // visits the method's code
        if (instructions.size() > 0) {
            mv.visitCode();
            // visits try catch blocks
            n = tryCatchBlocks == null ? 0 : tryCatchBlocks.size();
            for (i = 0; i < n; ++i) {
                tryCatchBlocks.get(i).accept(mv);
            }
            // visits instructions
            instructions.accept(mv);
            // visits local variables
            n = localVariables == null ? 0 : localVariables.size();
            for (i = 0; i < n; ++i) {
                localVariables.get(i).accept(mv);
            }
            // visits maxs
            mv.visitMaxs(maxStack, maxLocals);
            visited = true;
        }
        mv.visitEnd();
    }
}