org.ow2.asm/asm-tree/4.2 : org/objectweb/asm/MethodVisitor.java

MethodVisitor
http://asm.objectweb.org/asm-tree/: A very small and fast Java bytecode manipulation framework (ObjectWeb)
Eric Bruneton
Eugene Kuleshov
Remi Forax
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
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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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;

A visitor to visit a Java method. The methods of this class must be called in
the following order: [ visitAnnotationDefault ] (
visitAnnotation | visitParameterAnnotation |
visitAttribute )* [ visitCode ( visitFrame |
visitXInsn | visitLabel |
visitTryCatchBlock | visitLocalVariable |
visitLineNumber )* visitMaxs ] visitEnd. In
addition, the visitXInsn and visitLabel methods
must be called in the sequential order of the bytecode instructions of the
visited code, visitTryCatchBlock must be called before the
labels passed as arguments have been visited, and the
visitLocalVariable and visitLineNumber methods must be
called after the labels passed as arguments have been visited.
Author: Eric Bruneton/**
 * A visitor to visit a Java method. The methods of this class must be called in
 * the following order: [ <tt>visitAnnotationDefault</tt> ] (
 * <tt>visitAnnotation</tt> | <tt>visitParameterAnnotation</tt> |
 * <tt>visitAttribute</tt> )* [ <tt>visitCode</tt> ( <tt>visitFrame</tt> |
 * <tt>visit</tt><i>X</i>Insn</tt> | <tt>visitLabel</tt> |
 * <tt>visitTryCatchBlock</tt> | <tt>visitLocalVariable</tt> |
 * <tt>visitLineNumber</tt> )* <tt>visitMaxs</tt> ] <tt>visitEnd</tt>. In
 * addition, the <tt>visit</tt><i>X</i>Insn</tt> and <tt>visitLabel</tt> methods
 * must be called in the sequential order of the bytecode instructions of the
 * visited code, <tt>visitTryCatchBlock</tt> must be called <i>before</i> the
 * labels passed as arguments have been visited, and the
 * <tt>visitLocalVariable</tt> and <tt>visitLineNumber</tt> methods must be
 * called <i>after</i> the labels passed as arguments have been visited.
 * 
 * @author Eric Bruneton
 */
public abstract class MethodVisitor {

    The ASM API version implemented by this visitor. The value of this field must be one of Opcodes.ASM4. /**
     * The ASM API version implemented by this visitor. The value of this field
     * must be one of {@link Opcodes#ASM4}.
     */
    protected final int api;

    The method visitor to which this visitor must delegate method calls. May
be null.
/**
     * The method visitor to which this visitor must delegate method calls. May
     * be null.
     */
    protected MethodVisitor mv;

    Constructs a new MethodVisitor. 
Params: api –  the ASM API version implemented by this visitor. Must be one of Opcodes.ASM4./**
     * Constructs a new {@link MethodVisitor}.
     * 
     * @param api
     *            the ASM API version implemented by this visitor. Must be one
     *            of {@link Opcodes#ASM4}.
     */
    public MethodVisitor(final int api) {
        this(api, null);
    }

    Constructs a new MethodVisitor. 
Params: api –  the ASM API version implemented by this visitor. Must be one of Opcodes.ASM4.
mv – 
           the method visitor to which this visitor must delegate method
           calls. May be null./**
     * Constructs a new {@link MethodVisitor}.
     * 
     * @param api
     *            the ASM API version implemented by this visitor. Must be one
     *            of {@link Opcodes#ASM4}.
     * @param mv
     *            the method visitor to which this visitor must delegate method
     *            calls. May be null.
     */
    public MethodVisitor(final int api, final MethodVisitor mv) {
        if (api != Opcodes.ASM4) {
            throw new IllegalArgumentException();
        }
        this.api = api;
        this.mv = mv;
    }

    // -------------------------------------------------------------------------
    // Annotations and non standard attributes
    // -------------------------------------------------------------------------

    Visits the default value of this annotation interface method.
Returns: a visitor to the visit the actual default value of this
        annotation interface method, or null if this visitor is
        not interested in visiting this default value. The 'name'
        parameters passed to the methods of this annotation visitor are
        ignored. Moreover, exacly one visit method must be called on this
        annotation visitor, followed by visitEnd./**
     * Visits the default value of this annotation interface method.
     * 
     * @return a visitor to the visit the actual default value of this
     *         annotation interface method, or <tt>null</tt> if this visitor is
     *         not interested in visiting this default value. The 'name'
     *         parameters passed to the methods of this annotation visitor are
     *         ignored. Moreover, exacly one visit method must be called on this
     *         annotation visitor, followed by visitEnd.
     */
    public AnnotationVisitor visitAnnotationDefault() {
        if (mv != null) {
            return mv.visitAnnotationDefault();
        }
        return null;
    }

    Visits an annotation of this method.
Params: desc – 
           the class descriptor of the annotation class.
visible – 
           true if the annotation is visible at runtime.
Returns: a visitor to visit the annotation values, or null if
        this visitor is not interested in visiting this annotation./**
     * Visits an annotation of this method.
     * 
     * @param desc
     *            the class descriptor of the annotation class.
     * @param visible
     *            <tt>true</tt> if the annotation is visible at runtime.
     * @return a visitor to visit the annotation values, or <tt>null</tt> if
     *         this visitor is not interested in visiting this annotation.
     */
    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
        if (mv != null) {
            return mv.visitAnnotation(desc, visible);
        }
        return null;
    }

    Visits an annotation of a parameter this method.
Params: parameter – 
           the parameter index.
desc – 
           the class descriptor of the annotation class.
visible – 
           true if the annotation is visible at runtime.
Returns: a visitor to visit the annotation values, or null if
        this visitor is not interested in visiting this annotation./**
     * Visits an annotation of a parameter this method.
     * 
     * @param parameter
     *            the parameter index.
     * @param desc
     *            the class descriptor of the annotation class.
     * @param visible
     *            <tt>true</tt> if the annotation is visible at runtime.
     * @return a visitor to visit the annotation values, or <tt>null</tt> if
     *         this visitor is not interested in visiting this annotation.
     */
    public AnnotationVisitor visitParameterAnnotation(int parameter,
            String desc, boolean visible) {
        if (mv != null) {
            return mv.visitParameterAnnotation(parameter, desc, visible);
        }
        return null;
    }

    Visits a non standard attribute of this method.
Params: attr – 
           an attribute./**
     * Visits a non standard attribute of this method.
     * 
     * @param attr
     *            an attribute.
     */
    public void visitAttribute(Attribute attr) {
        if (mv != null) {
            mv.visitAttribute(attr);
        }
    }

    Starts the visit of the method's code, if any (i.e. non abstract method).
/**
     * Starts the visit of the method's code, if any (i.e. non abstract method).
     */
    public void visitCode() {
        if (mv != null) {
            mv.visitCode();
        }
    }

    Visits the current state of the local variables and operand stack
elements. This method must(*) be called just before any
instruction i that follows an unconditional branch instruction
such as GOTO or THROW, that is the target of a jump instruction, or that
starts an exception handler block. The visited types must describe the
values of the local variables and of the operand stack elements just
before i is executed.


 (*) this is mandatory only for classes whose version is greater than or equal to V1_6. 



The frames of a method must be given either in expanded form, or in
compressed form (all frames must use the same format, i.e. you must not
mix expanded and compressed frames within a single method):

In expanded form, all frames must have the F_NEW type.
In compressed form, frames are basically "deltas" from the state of
the previous frame:

Opcodes.F_SAME representing frame with exactly the same locals as the previous frame and with the empty stack.
Opcodes.F_SAME1 representing frame with exactly the same locals as the previous frame and with single value on the stack ( nStack is 1 and stack[0] contains value for the
type of the stack item).
Opcodes.F_APPEND representing frame with current locals are the same as the locals in the previous frame, except that additional locals are defined (nLocal is 1, 2 or 3 and
local elements contains values representing added types).
Opcodes.F_CHOP representing frame with current locals are the same as the locals in the previous frame, except that the last 1-3 locals are absent and with the empty stack (nLocals is 1, 2 or 3).
Opcodes.F_FULL representing complete frame data.

 

In both cases the first frame, corresponding to the method's parameters
and access flags, is implicit and must not be visited. Also, it is
illegal to visit two or more frames for the same code location (i.e., at
least one instruction must be visited between two calls to visitFrame).
Params: type –  the type of this stack map frame. Must be Opcodes.F_NEW for expanded frames, or Opcodes.F_FULL, Opcodes.F_APPEND, Opcodes.F_CHOP, Opcodes.F_SAME or Opcodes.F_APPEND, Opcodes.F_SAME1 for compressed frames.
nLocal – 
           the number of local variables in the visited frame.
local –  the local variable types in this frame. This array must not be modified. Primitive types are represented by Opcodes.TOP, Opcodes.INTEGER, Opcodes.FLOAT, Opcodes.LONG, Opcodes.DOUBLE,Opcodes.NULL or Opcodes.UNINITIALIZED_THIS (long and double are represented by a single element). Reference types are represented by String objects (representing internal names), and uninitialized types by Label objects (this label designates the NEW instruction that created this uninitialized value).
nStack – 
           the number of operand stack elements in the visited frame.
stack – 
           the operand stack types in this frame. This array must not be
           modified. Its content has the same format as the "local"
           array.
Throws: IllegalStateException – 
            if a frame is visited just after another one, without any
            instruction between the two (unless this frame is a
            Opcodes#F_SAME frame, in which case it is silently ignored)./**
     * Visits the current state of the local variables and operand stack
     * elements. This method must(*) be called <i>just before</i> any
     * instruction <b>i</b> that follows an unconditional branch instruction
     * such as GOTO or THROW, that is the target of a jump instruction, or that
     * starts an exception handler block. The visited types must describe the
     * values of the local variables and of the operand stack elements <i>just
     * before</i> <b>i</b> is executed.<br>
     * <br>
     * (*) this is mandatory only for classes whose version is greater than or
     * equal to {@link Opcodes#V1_6 V1_6}. <br>
     * <br>
     * The frames of a method must be given either in expanded form, or in
     * compressed form (all frames must use the same format, i.e. you must not
     * mix expanded and compressed frames within a single method):
     * <ul>
     * <li>In expanded form, all frames must have the F_NEW type.</li>
     * <li>In compressed form, frames are basically "deltas" from the state of
     * the previous frame:
     * <ul>
     * <li>{@link Opcodes#F_SAME} representing frame with exactly the same
     * locals as the previous frame and with the empty stack.</li>
     * <li>{@link Opcodes#F_SAME1} representing frame with exactly the same
     * locals as the previous frame and with single value on the stack (
     * <code>nStack</code> is 1 and <code>stack[0]</code> contains value for the
     * type of the stack item).</li>
     * <li>{@link Opcodes#F_APPEND} representing frame with current locals are
     * the same as the locals in the previous frame, except that additional
     * locals are defined (<code>nLocal</code> is 1, 2 or 3 and
     * <code>local</code> elements contains values representing added types).</li>
     * <li>{@link Opcodes#F_CHOP} representing frame with current locals are the
     * same as the locals in the previous frame, except that the last 1-3 locals
     * are absent and with the empty stack (<code>nLocals</code> is 1, 2 or 3).</li>
     * <li>{@link Opcodes#F_FULL} representing complete frame data.</li></li>
     * </ul>
     * </ul> <br>
     * In both cases the first frame, corresponding to the method's parameters
     * and access flags, is implicit and must not be visited. Also, it is
     * illegal to visit two or more frames for the same code location (i.e., at
     * least one instruction must be visited between two calls to visitFrame).
     * 
     * @param type
     *            the type of this stack map frame. Must be
     *            {@link Opcodes#F_NEW} for expanded frames, or
     *            {@link Opcodes#F_FULL}, {@link Opcodes#F_APPEND},
     *            {@link Opcodes#F_CHOP}, {@link Opcodes#F_SAME} or
     *            {@link Opcodes#F_APPEND}, {@link Opcodes#F_SAME1} for
     *            compressed frames.
     * @param nLocal
     *            the number of local variables in the visited frame.
     * @param local
     *            the local variable types in this frame. This array must not be
     *            modified. Primitive types are represented by
     *            {@link Opcodes#TOP}, {@link Opcodes#INTEGER},
     *            {@link Opcodes#FLOAT}, {@link Opcodes#LONG},
     *            {@link Opcodes#DOUBLE},{@link Opcodes#NULL} or
     *            {@link Opcodes#UNINITIALIZED_THIS} (long and double are
     *            represented by a single element). Reference types are
     *            represented by String objects (representing internal names),
     *            and uninitialized types by Label objects (this label
     *            designates the NEW instruction that created this uninitialized
     *            value).
     * @param nStack
     *            the number of operand stack elements in the visited frame.
     * @param stack
     *            the operand stack types in this frame. This array must not be
     *            modified. Its content has the same format as the "local"
     *            array.
     * @throws IllegalStateException
     *             if a frame is visited just after another one, without any
     *             instruction between the two (unless this frame is a
     *             Opcodes#F_SAME frame, in which case it is silently ignored).
     */
    public void visitFrame(int type, int nLocal, Object[] local, int nStack,
            Object[] stack) {
        if (mv != null) {
            mv.visitFrame(type, nLocal, local, nStack, stack);
        }
    }

    // -------------------------------------------------------------------------
    // Normal instructions
    // -------------------------------------------------------------------------

    Visits a zero operand instruction.
Params: opcode – 
           the opcode of the instruction to be visited. This opcode is
           either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1,
           ICONST_2, ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1,
           FCONST_0, FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD,
           LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD,
           IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE,
           SASTORE, POP, POP2, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1,
           DUP2_X2, SWAP, IADD, LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB,
           IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, FDIV, DDIV, IREM, LREM,
           FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL, LSHL, ISHR, LSHR,
           IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, I2L, I2F, I2D,
           L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, I2C, I2S,
           LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN, FRETURN,
           DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW, MONITORENTER,
           or MONITOREXIT./**
     * Visits a zero operand instruction.
     * 
     * @param opcode
     *            the opcode of the instruction to be visited. This opcode is
     *            either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1,
     *            ICONST_2, ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1,
     *            FCONST_0, FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD,
     *            LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD,
     *            IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE,
     *            SASTORE, POP, POP2, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1,
     *            DUP2_X2, SWAP, IADD, LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB,
     *            IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, FDIV, DDIV, IREM, LREM,
     *            FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL, LSHL, ISHR, LSHR,
     *            IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, I2L, I2F, I2D,
     *            L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, I2C, I2S,
     *            LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN, FRETURN,
     *            DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW, MONITORENTER,
     *            or MONITOREXIT.
     */
    public void visitInsn(int opcode) {
        if (mv != null) {
            mv.visitInsn(opcode);
        }
    }

    Visits an instruction with a single int operand.
Params: opcode – 
           the opcode of the instruction to be visited. This opcode is
           either BIPUSH, SIPUSH or NEWARRAY.
operand – 
           the operand of the instruction to be visited.

           When opcode is BIPUSH, operand value should be between
           Byte.MIN_VALUE and Byte.MAX_VALUE.

           When opcode is SIPUSH, operand value should be between
           Short.MIN_VALUE and Short.MAX_VALUE.
 When opcode is NEWARRAY, operand value should be one of Opcodes.T_BOOLEAN, Opcodes.T_CHAR, Opcodes.T_FLOAT, Opcodes.T_DOUBLE, Opcodes.T_BYTE, Opcodes.T_SHORT, Opcodes.T_INT or Opcodes.T_LONG./**
     * Visits an instruction with a single int operand.
     * 
     * @param opcode
     *            the opcode of the instruction to be visited. This opcode is
     *            either BIPUSH, SIPUSH or NEWARRAY.
     * @param operand
     *            the operand of the instruction to be visited.<br>
     *            When opcode is BIPUSH, operand value should be between
     *            Byte.MIN_VALUE and Byte.MAX_VALUE.<br>
     *            When opcode is SIPUSH, operand value should be between
     *            Short.MIN_VALUE and Short.MAX_VALUE.<br>
     *            When opcode is NEWARRAY, operand value should be one of
     *            {@link Opcodes#T_BOOLEAN}, {@link Opcodes#T_CHAR},
     *            {@link Opcodes#T_FLOAT}, {@link Opcodes#T_DOUBLE},
     *            {@link Opcodes#T_BYTE}, {@link Opcodes#T_SHORT},
     *            {@link Opcodes#T_INT} or {@link Opcodes#T_LONG}.
     */
    public void visitIntInsn(int opcode, int operand) {
        if (mv != null) {
            mv.visitIntInsn(opcode, operand);
        }
    }

    Visits a local variable instruction. A local variable instruction is an
instruction that loads or stores the value of a local variable.
Params: opcode – 
           the opcode of the local variable instruction to be visited.
           This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD,
           ISTORE, LSTORE, FSTORE, DSTORE, ASTORE or RET.
var – 
           the operand of the instruction to be visited. This operand is
           the index of a local variable./**
     * Visits a local variable instruction. A local variable instruction is an
     * instruction that loads or stores the value of a local variable.
     * 
     * @param opcode
     *            the opcode of the local variable instruction to be visited.
     *            This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD,
     *            ISTORE, LSTORE, FSTORE, DSTORE, ASTORE or RET.
     * @param var
     *            the operand of the instruction to be visited. This operand is
     *            the index of a local variable.
     */
    public void visitVarInsn(int opcode, int var) {
        if (mv != null) {
            mv.visitVarInsn(opcode, var);
        }
    }

    Visits a type instruction. A type instruction is an instruction that
takes the internal name of a class as parameter.
Params: opcode – 
           the opcode of the type instruction to be visited. This opcode
           is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.
type –  the operand of the instruction to be visited. This operand must be the internal name of an object or array class (see getInternalName)./**
     * Visits a type instruction. A type instruction is an instruction that
     * takes the internal name of a class as parameter.
     * 
     * @param opcode
     *            the opcode of the type instruction to be visited. This opcode
     *            is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.
     * @param type
     *            the operand of the instruction to be visited. This operand
     *            must be the internal name of an object or array class (see
     *            {@link Type#getInternalName() getInternalName}).
     */
    public void visitTypeInsn(int opcode, String type) {
        if (mv != null) {
            mv.visitTypeInsn(opcode, type);
        }
    }

    Visits a field instruction. A field instruction is an instruction that
loads or stores the value of a field of an object.
Params: opcode – 
           the opcode of the type instruction to be visited. This opcode
           is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.
owner –  the internal name of the field's owner class (see getInternalName).
name – 
           the field's name.
desc –  the field's descriptor (see Type)./**
     * Visits a field instruction. A field instruction is an instruction that
     * loads or stores the value of a field of an object.
     * 
     * @param opcode
     *            the opcode of the type instruction to be visited. This opcode
     *            is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.
     * @param owner
     *            the internal name of the field's owner class (see
     *            {@link Type#getInternalName() getInternalName}).
     * @param name
     *            the field's name.
     * @param desc
     *            the field's descriptor (see {@link Type Type}).
     */
    public void visitFieldInsn(int opcode, String owner, String name,
            String desc) {
        if (mv != null) {
            mv.visitFieldInsn(opcode, owner, name, desc);
        }
    }

    Visits a method instruction. A method instruction is an instruction that
invokes a method.
Params: opcode – 
           the opcode of the type instruction to be visited. This opcode
           is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or
           INVOKEINTERFACE.
owner –  the internal name of the method's owner class (see getInternalName).
name – 
           the method's name.
desc –  the method's descriptor (see Type)./**
     * Visits a method instruction. A method instruction is an instruction that
     * invokes a method.
     * 
     * @param opcode
     *            the opcode of the type instruction to be visited. This opcode
     *            is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or
     *            INVOKEINTERFACE.
     * @param owner
     *            the internal name of the method's owner class (see
     *            {@link Type#getInternalName() getInternalName}).
     * @param name
     *            the method's name.
     * @param desc
     *            the method's descriptor (see {@link Type Type}).
     */
    public void visitMethodInsn(int opcode, String owner, String name,
            String desc) {
        if (mv != null) {
            mv.visitMethodInsn(opcode, owner, name, desc);
        }
    }

    Visits an invokedynamic instruction.
Params: name – 
           the method's name.
desc –  the method's descriptor (see Type).
bsm – 
           the bootstrap method.
bsmArgs –  the bootstrap method constant arguments. Each argument must be an Integer, Float, Long, Double, String, Type or Handle value. This method is allowed to modify the content of the array so a caller should expect that this array may change./**
     * Visits an invokedynamic instruction.
     * 
     * @param name
     *            the method's name.
     * @param desc
     *            the method's descriptor (see {@link Type Type}).
     * @param bsm
     *            the bootstrap method.
     * @param bsmArgs
     *            the bootstrap method constant arguments. Each argument must be
     *            an {@link Integer}, {@link Float}, {@link Long},
     *            {@link Double}, {@link String}, {@link Type} or {@link Handle}
     *            value. This method is allowed to modify the content of the
     *            array so a caller should expect that this array may change.
     */
    public void visitInvokeDynamicInsn(String name, String desc, Handle bsm,
            Object... bsmArgs) {
        if (mv != null) {
            mv.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
        }
    }

    Visits a jump instruction. A jump instruction is an instruction that may
jump to another instruction.
Params: opcode – 
           the opcode of the type instruction to be visited. This opcode
           is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ,
           IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE,
           IF_ACMPEQ, IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.
label – 
           the operand of the instruction to be visited. This operand is
           a label that designates the instruction to which the jump
           instruction may jump./**
     * Visits a jump instruction. A jump instruction is an instruction that may
     * jump to another instruction.
     * 
     * @param opcode
     *            the opcode of the type instruction to be visited. This opcode
     *            is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ,
     *            IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE,
     *            IF_ACMPEQ, IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.
     * @param label
     *            the operand of the instruction to be visited. This operand is
     *            a label that designates the instruction to which the jump
     *            instruction may jump.
     */
    public void visitJumpInsn(int opcode, Label label) {
        if (mv != null) {
            mv.visitJumpInsn(opcode, label);
        }
    }

    Visits a label. A label designates the instruction that will be visited
just after it.
Params: label –  a Label object./**
     * Visits a label. A label designates the instruction that will be visited
     * just after it.
     * 
     * @param label
     *            a {@link Label Label} object.
     */
    public void visitLabel(Label label) {
        if (mv != null) {
            mv.visitLabel(label);
        }
    }

    // -------------------------------------------------------------------------
    // Special instructions
    // -------------------------------------------------------------------------

    Visits a LDC instruction. Note that new constant types may be added in
future versions of the Java Virtual Machine. To easily detect new
constant types, implementations of this method should check for
unexpected constant types, like this:
if (cst instanceof Integer) {
    // ...
} else if (cst instanceof Float) {
    // ...
} else if (cst instanceof Long) {
    // ...
} else if (cst instanceof Double) {
    // ...
} else if (cst instanceof String) {
    // ...
} else if (cst instanceof Type) {
    int sort = ((Type) cst).getSort();
    if (sort == Type.OBJECT) {
        // ...
    } else if (sort == Type.ARRAY) {
        // ...
    } else if (sort == Type.METHOD) {
        // ...
    } else {
        // throw an exception
    }
} else if (cst instanceof Handle) {
    // ...
} else {
    // throw an exception
}

Params: cst –  the constant to be loaded on the stack. This parameter must be a non null Integer, a Float, a Long, a Double, a String, a Type of OBJECT or ARRAY sort for .class constants, for classes whose version is 49.0, a Type of METHOD sort or a Handle for MethodType and MethodHandle constants, for classes whose version is 51.0./**
     * Visits a LDC instruction. Note that new constant types may be added in
     * future versions of the Java Virtual Machine. To easily detect new
     * constant types, implementations of this method should check for
     * unexpected constant types, like this:
     * 
     * <pre>
     * if (cst instanceof Integer) {
     *     // ...
     * } else if (cst instanceof Float) {
     *     // ...
     * } else if (cst instanceof Long) {
     *     // ...
     * } else if (cst instanceof Double) {
     *     // ...
     * } else if (cst instanceof String) {
     *     // ...
     * } else if (cst instanceof Type) {
     *     int sort = ((Type) cst).getSort();
     *     if (sort == Type.OBJECT) {
     *         // ...
     *     } else if (sort == Type.ARRAY) {
     *         // ...
     *     } else if (sort == Type.METHOD) {
     *         // ...
     *     } else {
     *         // throw an exception
     *     }
     * } else if (cst instanceof Handle) {
     *     // ...
     * } else {
     *     // throw an exception
     * }
     * </pre>
     * 
     * @param cst
     *            the constant to be loaded on the stack. This parameter must be
     *            a non null {@link Integer}, a {@link Float}, a {@link Long}, a
     *            {@link Double}, a {@link String}, a {@link Type} of OBJECT or
     *            ARRAY sort for <tt>.class</tt> constants, for classes whose
     *            version is 49.0, a {@link Type} of METHOD sort or a
     *            {@link Handle} for MethodType and MethodHandle constants, for
     *            classes whose version is 51.0.
     */
    public void visitLdcInsn(Object cst) {
        if (mv != null) {
            mv.visitLdcInsn(cst);
        }
    }

    Visits an IINC instruction.
Params: var – 
           index of the local variable to be incremented.
increment – 
           amount to increment the local variable by./**
     * Visits an IINC instruction.
     * 
     * @param var
     *            index of the local variable to be incremented.
     * @param increment
     *            amount to increment the local variable by.
     */
    public void visitIincInsn(int var, int increment) {
        if (mv != null) {
            mv.visitIincInsn(var, increment);
        }
    }

    Visits a TABLESWITCH instruction.
Params: min – 
           the minimum key value.
max – 
           the maximum key value.
dflt – 
           beginning of the default handler block.
labels – 
           beginnings of the handler blocks. labels[i] is the
           beginning of the handler block for the min + i key./**
     * Visits a TABLESWITCH instruction.
     * 
     * @param min
     *            the minimum key value.
     * @param max
     *            the maximum key value.
     * @param dflt
     *            beginning of the default handler block.
     * @param labels
     *            beginnings of the handler blocks. <tt>labels[i]</tt> is the
     *            beginning of the handler block for the <tt>min + i</tt> key.
     */
    public void visitTableSwitchInsn(int min, int max, Label dflt,
            Label... labels) {
        if (mv != null) {
            mv.visitTableSwitchInsn(min, max, dflt, labels);
        }
    }

    Visits a LOOKUPSWITCH instruction.
Params: dflt – 
           beginning of the default handler block.
keys – 
           the values of the keys.
labels – 
           beginnings of the handler blocks. labels[i] is the
           beginning of the handler block for the keys[i] key./**
     * Visits a LOOKUPSWITCH instruction.
     * 
     * @param dflt
     *            beginning of the default handler block.
     * @param keys
     *            the values of the keys.
     * @param labels
     *            beginnings of the handler blocks. <tt>labels[i]</tt> is the
     *            beginning of the handler block for the <tt>keys[i]</tt> key.
     */
    public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) {
        if (mv != null) {
            mv.visitLookupSwitchInsn(dflt, keys, labels);
        }
    }

    Visits a MULTIANEWARRAY instruction.
Params: desc –  an array type descriptor (see Type).
dims – 
           number of dimensions of the array to allocate./**
     * Visits a MULTIANEWARRAY instruction.
     * 
     * @param desc
     *            an array type descriptor (see {@link Type Type}).
     * @param dims
     *            number of dimensions of the array to allocate.
     */
    public void visitMultiANewArrayInsn(String desc, int dims) {
        if (mv != null) {
            mv.visitMultiANewArrayInsn(desc, dims);
        }
    }

    // -------------------------------------------------------------------------
    // Exceptions table entries, debug information, max stack and max locals
    // -------------------------------------------------------------------------

    Visits a try catch block.
Params: start – 
           beginning of the exception handler's scope (inclusive).
end – 
           end of the exception handler's scope (exclusive).
handler – 
           beginning of the exception handler's code.
type – 
           internal name of the type of exceptions handled by the
           handler, or null to catch any exceptions (for
           "finally" blocks).
Throws: IllegalArgumentException –  if one of the labels has already been visited by this visitor (by the visitLabel method)./**
     * Visits a try catch block.
     * 
     * @param start
     *            beginning of the exception handler's scope (inclusive).
     * @param end
     *            end of the exception handler's scope (exclusive).
     * @param handler
     *            beginning of the exception handler's code.
     * @param type
     *            internal name of the type of exceptions handled by the
     *            handler, or <tt>null</tt> to catch any exceptions (for
     *            "finally" blocks).
     * @throws IllegalArgumentException
     *             if one of the labels has already been visited by this visitor
     *             (by the {@link #visitLabel visitLabel} method).
     */
    public void visitTryCatchBlock(Label start, Label end, Label handler,
            String type) {
        if (mv != null) {
            mv.visitTryCatchBlock(start, end, handler, type);
        }
    }

    Visits a local variable declaration.
Params: name – 
           the name of a local variable.
desc – 
           the type descriptor of this local variable.
signature – 
           the type signature of this local variable. May be
           null if the local variable type does not use generic
           types.
start – 
           the first instruction corresponding to the scope of this local
           variable (inclusive).
end – 
           the last instruction corresponding to the scope of this local
           variable (exclusive).
index – 
           the local variable's index.
Throws: IllegalArgumentException –  if one of the labels has not already been visited by this visitor (by the visitLabel method)./**
     * Visits a local variable declaration.
     * 
     * @param name
     *            the name of a local variable.
     * @param desc
     *            the type descriptor of this local variable.
     * @param signature
     *            the type signature of this local variable. May be
     *            <tt>null</tt> if the local variable type does not use generic
     *            types.
     * @param start
     *            the first instruction corresponding to the scope of this local
     *            variable (inclusive).
     * @param end
     *            the last instruction corresponding to the scope of this local
     *            variable (exclusive).
     * @param index
     *            the local variable's index.
     * @throws IllegalArgumentException
     *             if one of the labels has not already been visited by this
     *             visitor (by the {@link #visitLabel visitLabel} method).
     */
    public void visitLocalVariable(String name, String desc, String signature,
            Label start, Label end, int index) {
        if (mv != null) {
            mv.visitLocalVariable(name, desc, signature, start, end, index);
        }
    }

    Visits a line number declaration.
Params: line – 
           a line number. This number refers to the source file from
           which the class was compiled.
start – 
           the first instruction corresponding to this line number.
Throws: IllegalArgumentException – 
            if start has not already been visited by this visitor (by the visitLabel method)./**
     * Visits a line number declaration.
     * 
     * @param line
     *            a line number. This number refers to the source file from
     *            which the class was compiled.
     * @param start
     *            the first instruction corresponding to this line number.
     * @throws IllegalArgumentException
     *             if <tt>start</tt> has not already been visited by this
     *             visitor (by the {@link #visitLabel visitLabel} method).
     */
    public void visitLineNumber(int line, Label start) {
        if (mv != null) {
            mv.visitLineNumber(line, start);
        }
    }

    Visits the maximum stack size and the maximum number of local variables
of the method.
Params: maxStack – 
           maximum stack size of the method.
maxLocals – 
           maximum number of local variables for the method./**
     * Visits the maximum stack size and the maximum number of local variables
     * of the method.
     * 
     * @param maxStack
     *            maximum stack size of the method.
     * @param maxLocals
     *            maximum number of local variables for the method.
     */
    public void visitMaxs(int maxStack, int maxLocals) {
        if (mv != null) {
            mv.visitMaxs(maxStack, maxLocals);
        }
    }

    Visits the end of the method. This method, which is the last one to be
called, is used to inform the visitor that all the annotations and
attributes of the method have been visited.
/**
     * Visits the end of the method. This method, which is the last one to be
     * called, is used to inform the visitor that all the annotations and
     * attributes of the method have been visited.
     */
    public void visitEnd() {
        if (mv != null) {
            mv.visitEnd();
        }
    }
}
Params:	desc – the class descriptor of the annotation class. visible – `true` if the annotation is visible at runtime.
Returns:	a visitor to visit the annotation values, or `null` if this visitor is not interested in visiting this annotation.
Params:	parameter – the parameter index. desc – the class descriptor of the annotation class. visible – `true` if the annotation is visible at runtime.
Returns:	a visitor to visit the annotation values, or `null` if this visitor is not interested in visiting this annotation.
Params:	start – beginning of the exception handler's scope (inclusive). end – end of the exception handler's scope (exclusive). handler – beginning of the exception handler's code. type – internal name of the type of exceptions handled by the handler, or `null` to catch any exceptions (for "finally" blocks).
Throws:	IllegalArgumentException – if one of the labels has already been visited by this visitor (by the `visitLabel` method).
Params:	line – a line number. This number refers to the source file from which the class was compiled. start – the first instruction corresponding to this line number.
Throws:	IllegalArgumentException – if `start` has not already been visited by this visitor (by the `visitLabel` method).
/

org.ow2.asm/ asm-tree/ 4.2/ org/objectweb/asm/MethodVisitor.java
