001/***
002 * ASM: a very small and fast Java bytecode manipulation framework
003 * Copyright (c) 2000-2011 INRIA, France Telecom
004 * All rights reserved.
005 *
006 * Redistribution and use in source and binary forms, with or without
007 * modification, are permitted provided that the following conditions
008 * are met:
009 * 1. Redistributions of source code must retain the above copyright
010 *    notice, this list of conditions and the following disclaimer.
011 * 2. Redistributions in binary form must reproduce the above copyright
012 *    notice, this list of conditions and the following disclaimer in the
013 *    documentation and/or other materials provided with the distribution.
014 * 3. Neither the name of the copyright holders nor the names of its
015 *    contributors may be used to endorse or promote products derived from
016 *    this software without specific prior written permission.
017 *
018 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
019 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
020 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
021 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
022 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
023 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
024 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
025 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
026 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
027 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
028 * THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package io.ebean.enhance.asm;
031
032/**
033 * A visitor to visit a Java method. The methods of this class must be called in
034 * the following order: ( <tt>visitParameter</tt> )* [
035 * <tt>visitAnnotationDefault</tt> ] ( <tt>visitAnnotation</tt> |
036 * <tt>visitParameterAnnotation</tt> <tt>visitTypeAnnotation</tt> |
037 * <tt>visitAttribute</tt> )* [ <tt>visitCode</tt> ( <tt>visitFrame</tt> |
038 * <tt>visit<i>X</i>Insn</tt> | <tt>visitLabel</tt> |
039 * <tt>visitInsnAnnotation</tt> | <tt>visitTryCatchBlock</tt> |
040 * <tt>visitTryCatchAnnotation</tt> | <tt>visitLocalVariable</tt> |
041 * <tt>visitLocalVariableAnnotation</tt> | <tt>visitLineNumber</tt> )*
042 * <tt>visitMaxs</tt> ] <tt>visitEnd</tt>. In addition, the
043 * <tt>visit<i>X</i>Insn</tt> and <tt>visitLabel</tt> methods must be called in
044 * the sequential order of the bytecode instructions of the visited code,
045 * <tt>visitInsnAnnotation</tt> must be called <i>after</i> the annotated
046 * instruction, <tt>visitTryCatchBlock</tt> must be called <i>before</i> the
047 * labels passed as arguments have been visited,
048 * <tt>visitTryCatchBlockAnnotation</tt> must be called <i>after</i> the
049 * corresponding try catch block has been visited, and the
050 * <tt>visitLocalVariable</tt>, <tt>visitLocalVariableAnnotation</tt> and
051 * <tt>visitLineNumber</tt> methods must be called <i>after</i> the labels
052 * passed as arguments have been visited.
053 * 
054 * @author Eric Bruneton
055 */
056public abstract class MethodVisitor {
057
058    /**
059     * The ASM API version implemented by this visitor. The value of this field
060     * must be one of {@link Opcodes#ASM4}, {@link Opcodes#ASM5} or {@link Opcodes#ASM6}.
061     */
062    protected final int api;
063
064    /**
065     * The method visitor to which this visitor must delegate method calls. May
066     * be null.
067     */
068    protected MethodVisitor mv;
069
070    /**
071     * Constructs a new {@link MethodVisitor}.
072     * 
073     * @param api
074     *            the ASM API version implemented by this visitor. Must be one
075     *            of {@link Opcodes#ASM4}, {@link Opcodes#ASM5} or {@link Opcodes#ASM6}.
076     */
077    public MethodVisitor(final int api) {
078        this(api, null);
079    }
080
081    /**
082     * Constructs a new {@link MethodVisitor}.
083     * 
084     * @param api
085     *            the ASM API version implemented by this visitor. Must be one
086     *            of {@link Opcodes#ASM4}, {@link Opcodes#ASM5} or {@link Opcodes#ASM6}.
087     * @param mv
088     *            the method visitor to which this visitor must delegate method
089     *            calls. May be null.
090     */
091    public MethodVisitor(final int api, final MethodVisitor mv) {
092        if (api < Opcodes.ASM4 || api > Opcodes.ASM6) {
093            throw new IllegalArgumentException();
094        }
095        this.api = api;
096        this.mv = mv;
097    }
098
099    // -------------------------------------------------------------------------
100    // Parameters, annotations and non standard attributes
101    // -------------------------------------------------------------------------
102
103    /**
104     * Visits a parameter of this method.
105     * 
106     * @param name
107     *            parameter name or null if none is provided.
108     * @param access
109     *            the parameter's access flags, only <tt>ACC_FINAL</tt>,
110     *            <tt>ACC_SYNTHETIC</tt> or/and <tt>ACC_MANDATED</tt> are
111     *            allowed (see {@link Opcodes}).
112     */
113    public void visitParameter(String name, int access) {
114        if (api < Opcodes.ASM5) {
115            throw new RuntimeException();
116        }
117        if (mv != null) {
118            mv.visitParameter(name, access);
119        }
120    }
121
122    /**
123     * Visits the default value of this annotation interface method.
124     * 
125     * @return a visitor to the visit the actual default value of this
126     *         annotation interface method, or <tt>null</tt> if this visitor is
127     *         not interested in visiting this default value. The 'name'
128     *         parameters passed to the methods of this annotation visitor are
129     *         ignored. Moreover, exacly one visit method must be called on this
130     *         annotation visitor, followed by visitEnd.
131     */
132    public AnnotationVisitor visitAnnotationDefault() {
133        if (mv != null) {
134            return mv.visitAnnotationDefault();
135        }
136        return null;
137    }
138
139    /**
140     * Visits an annotation of this method.
141     * 
142     * @param desc
143     *            the class descriptor of the annotation class.
144     * @param visible
145     *            <tt>true</tt> if the annotation is visible at runtime.
146     * @return a visitor to visit the annotation values, or <tt>null</tt> if
147     *         this visitor is not interested in visiting this annotation.
148     */
149    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
150        if (mv != null) {
151            return mv.visitAnnotation(desc, visible);
152        }
153        return null;
154    }
155
156    /**
157     * Visits an annotation on a type in the method signature.
158     * 
159     * @param typeRef
160     *            a reference to the annotated type. The sort of this type
161     *            reference must be {@link TypeReference#METHOD_TYPE_PARAMETER
162     *            METHOD_TYPE_PARAMETER},
163     *            {@link TypeReference#METHOD_TYPE_PARAMETER_BOUND
164     *            METHOD_TYPE_PARAMETER_BOUND},
165     *            {@link TypeReference#METHOD_RETURN METHOD_RETURN},
166     *            {@link TypeReference#METHOD_RECEIVER METHOD_RECEIVER},
167     *            {@link TypeReference#METHOD_FORMAL_PARAMETER
168     *            METHOD_FORMAL_PARAMETER} or {@link TypeReference#THROWS
169     *            THROWS}. See {@link TypeReference}.
170     * @param typePath
171     *            the path to the annotated type argument, wildcard bound, array
172     *            element type, or static inner type within 'typeRef'. May be
173     *            <tt>null</tt> if the annotation targets 'typeRef' as a whole.
174     * @param desc
175     *            the class descriptor of the annotation class.
176     * @param visible
177     *            <tt>true</tt> if the annotation is visible at runtime.
178     * @return a visitor to visit the annotation values, or <tt>null</tt> if
179     *         this visitor is not interested in visiting this annotation.
180     */
181    public AnnotationVisitor visitTypeAnnotation(int typeRef,
182                                                 TypePath typePath, String desc, boolean visible) {
183        if (api < Opcodes.ASM5) {
184            throw new RuntimeException();
185        }
186        if (mv != null) {
187            return mv.visitTypeAnnotation(typeRef, typePath, desc, visible);
188        }
189        return null;
190    }
191
192    /**
193     * Visits an annotation of a parameter this method.
194     * 
195     * @param parameter
196     *            the parameter index.
197     * @param desc
198     *            the class descriptor of the annotation class.
199     * @param visible
200     *            <tt>true</tt> if the annotation is visible at runtime.
201     * @return a visitor to visit the annotation values, or <tt>null</tt> if
202     *         this visitor is not interested in visiting this annotation.
203     */
204    public AnnotationVisitor visitParameterAnnotation(int parameter,
205                                                      String desc, boolean visible) {
206        if (mv != null) {
207            return mv.visitParameterAnnotation(parameter, desc, visible);
208        }
209        return null;
210    }
211
212    /**
213     * Visits a non standard attribute of this method.
214     * 
215     * @param attr
216     *            an attribute.
217     */
218    public void visitAttribute(Attribute attr) {
219        if (mv != null) {
220            mv.visitAttribute(attr);
221        }
222    }
223
224    /**
225     * Starts the visit of the method's code, if any (i.e. non abstract method).
226     */
227    public void visitCode() {
228        if (mv != null) {
229            mv.visitCode();
230        }
231    }
232
233    /**
234     * Visits the current state of the local variables and operand stack
235     * elements. This method must(*) be called <i>just before</i> any
236     * instruction <b>i</b> that follows an unconditional branch instruction
237     * such as GOTO or THROW, that is the target of a jump instruction, or that
238     * starts an exception handler block. The visited types must describe the
239     * values of the local variables and of the operand stack elements <i>just
240     * before</i> <b>i</b> is executed.<br>
241     * <br>
242     * (*) this is mandatory only for classes whose version is greater than or
243     * equal to {@link Opcodes#V1_6 V1_6}. <br>
244     * <br>
245     * The frames of a method must be given either in expanded form, or in
246     * compressed form (all frames must use the same format, i.e. you must not
247     * mix expanded and compressed frames within a single method):
248     * <ul>
249     * <li>In expanded form, all frames must have the F_NEW type.</li>
250     * <li>In compressed form, frames are basically "deltas" from the state of
251     * the previous frame:
252     * <ul>
253     * <li>{@link Opcodes#F_SAME} representing frame with exactly the same
254     * locals as the previous frame and with the empty stack.</li>
255     * <li>{@link Opcodes#F_SAME1} representing frame with exactly the same
256     * locals as the previous frame and with single value on the stack (
257     * <code>nStack</code> is 1 and <code>stack[0]</code> contains value for the
258     * type of the stack item).</li>
259     * <li>{@link Opcodes#F_APPEND} representing frame with current locals are
260     * the same as the locals in the previous frame, except that additional
261     * locals are defined (<code>nLocal</code> is 1, 2 or 3 and
262     * <code>local</code> elements contains values representing added types).</li>
263     * <li>{@link Opcodes#F_CHOP} representing frame with current locals are the
264     * same as the locals in the previous frame, except that the last 1-3 locals
265     * are absent and with the empty stack (<code>nLocals</code> is 1, 2 or 3).</li>
266     * <li>{@link Opcodes#F_FULL} representing complete frame data.</li>
267     * </ul>
268     * </li>
269     * </ul>
270     * <br>
271     * In both cases the first frame, corresponding to the method's parameters
272     * and access flags, is implicit and must not be visited. Also, it is
273     * illegal to visit two or more frames for the same code location (i.e., at
274     * least one instruction must be visited between two calls to visitFrame).
275     * 
276     * @param type
277     *            the type of this stack map frame. Must be
278     *            {@link Opcodes#F_NEW} for expanded frames, or
279     *            {@link Opcodes#F_FULL}, {@link Opcodes#F_APPEND},
280     *            {@link Opcodes#F_CHOP}, {@link Opcodes#F_SAME} or
281     *            {@link Opcodes#F_APPEND}, {@link Opcodes#F_SAME1} for
282     *            compressed frames.
283     * @param nLocal
284     *            the number of local variables in the visited frame.
285     * @param local
286     *            the local variable types in this frame. This array must not be
287     *            modified. Primitive types are represented by
288     *            {@link Opcodes#TOP}, {@link Opcodes#INTEGER},
289     *            {@link Opcodes#FLOAT}, {@link Opcodes#LONG},
290     *            {@link Opcodes#DOUBLE},{@link Opcodes#NULL} or
291     *            {@link Opcodes#UNINITIALIZED_THIS} (long and double are
292     *            represented by a single element). Reference types are
293     *            represented by String objects (representing internal names),
294     *            and uninitialized types by Label objects (this label
295     *            designates the NEW instruction that created this uninitialized
296     *            value).
297     * @param nStack
298     *            the number of operand stack elements in the visited frame.
299     * @param stack
300     *            the operand stack types in this frame. This array must not be
301     *            modified. Its content has the same format as the "local"
302     *            array.
303     * @throws IllegalStateException
304     *             if a frame is visited just after another one, without any
305     *             instruction between the two (unless this frame is a
306     *             Opcodes#F_SAME frame, in which case it is silently ignored).
307     */
308    public void visitFrame(int type, int nLocal, Object[] local, int nStack,
309            Object[] stack) {
310        if (mv != null) {
311            mv.visitFrame(type, nLocal, local, nStack, stack);
312        }
313    }
314
315    // -------------------------------------------------------------------------
316    // Normal instructions
317    // -------------------------------------------------------------------------
318
319    /**
320     * Visits a zero operand instruction.
321     * 
322     * @param opcode
323     *            the opcode of the instruction to be visited. This opcode is
324     *            either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1,
325     *            ICONST_2, ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1,
326     *            FCONST_0, FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD,
327     *            LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD,
328     *            IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE,
329     *            SASTORE, POP, POP2, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1,
330     *            DUP2_X2, SWAP, IADD, LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB,
331     *            IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, FDIV, DDIV, IREM, LREM,
332     *            FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL, LSHL, ISHR, LSHR,
333     *            IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, I2L, I2F, I2D,
334     *            L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, I2C, I2S,
335     *            LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN, FRETURN,
336     *            DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW, MONITORENTER,
337     *            or MONITOREXIT.
338     */
339    public void visitInsn(int opcode) {
340        if (mv != null) {
341            mv.visitInsn(opcode);
342        }
343    }
344
345    /**
346     * Visits an instruction with a single int operand.
347     * 
348     * @param opcode
349     *            the opcode of the instruction to be visited. This opcode is
350     *            either BIPUSH, SIPUSH or NEWARRAY.
351     * @param operand
352     *            the operand of the instruction to be visited.<br>
353     *            When opcode is BIPUSH, operand value should be between
354     *            Byte.MIN_VALUE and Byte.MAX_VALUE.<br>
355     *            When opcode is SIPUSH, operand value should be between
356     *            Short.MIN_VALUE and Short.MAX_VALUE.<br>
357     *            When opcode is NEWARRAY, operand value should be one of
358     *            {@link Opcodes#T_BOOLEAN}, {@link Opcodes#T_CHAR},
359     *            {@link Opcodes#T_FLOAT}, {@link Opcodes#T_DOUBLE},
360     *            {@link Opcodes#T_BYTE}, {@link Opcodes#T_SHORT},
361     *            {@link Opcodes#T_INT} or {@link Opcodes#T_LONG}.
362     */
363    public void visitIntInsn(int opcode, int operand) {
364        if (mv != null) {
365            mv.visitIntInsn(opcode, operand);
366        }
367    }
368
369    /**
370     * Visits a local variable instruction. A local variable instruction is an
371     * instruction that loads or stores the value of a local variable.
372     * 
373     * @param opcode
374     *            the opcode of the local variable instruction to be visited.
375     *            This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD,
376     *            ISTORE, LSTORE, FSTORE, DSTORE, ASTORE or RET.
377     * @param var
378     *            the operand of the instruction to be visited. This operand is
379     *            the index of a local variable.
380     */
381    public void visitVarInsn(int opcode, int var) {
382        if (mv != null) {
383            mv.visitVarInsn(opcode, var);
384        }
385    }
386
387    /**
388     * Visits a type instruction. A type instruction is an instruction that
389     * takes the internal name of a class as parameter.
390     * 
391     * @param opcode
392     *            the opcode of the type instruction to be visited. This opcode
393     *            is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.
394     * @param type
395     *            the operand of the instruction to be visited. This operand
396     *            must be the internal name of an object or array class (see
397     *            {@link Type#getInternalName() getInternalName}).
398     */
399    public void visitTypeInsn(int opcode, String type) {
400        if (mv != null) {
401            mv.visitTypeInsn(opcode, type);
402        }
403    }
404
405    /**
406     * Visits a field instruction. A field instruction is an instruction that
407     * loads or stores the value of a field of an object.
408     * 
409     * @param opcode
410     *            the opcode of the type instruction to be visited. This opcode
411     *            is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.
412     * @param owner
413     *            the internal name of the field's owner class (see
414     *            {@link Type#getInternalName() getInternalName}).
415     * @param name
416     *            the field's name.
417     * @param desc
418     *            the field's descriptor (see {@link Type Type}).
419     */
420    public void visitFieldInsn(int opcode, String owner, String name,
421            String desc) {
422        if (mv != null) {
423            mv.visitFieldInsn(opcode, owner, name, desc);
424        }
425    }
426
427    /**
428     * Visits a method instruction. A method instruction is an instruction that
429     * invokes a method.
430     * 
431     * @param opcode
432     *            the opcode of the type instruction to be visited. This opcode
433     *            is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or
434     *            INVOKEINTERFACE.
435     * @param owner
436     *            the internal name of the method's owner class (see
437     *            {@link Type#getInternalName() getInternalName}).
438     * @param name
439     *            the method's name.
440     * @param desc
441     *            the method's descriptor (see {@link Type Type}).
442     */
443    @Deprecated
444    public void visitMethodInsn(int opcode, String owner, String name,
445            String desc) {
446        if (api >= Opcodes.ASM5) {
447            boolean itf = opcode == Opcodes.INVOKEINTERFACE;
448            visitMethodInsn(opcode, owner, name, desc, itf);
449            return;
450        }
451        if (mv != null) {
452            mv.visitMethodInsn(opcode, owner, name, desc);
453        }
454    }
455
456    /**
457     * Visits a method instruction. A method instruction is an instruction that
458     * invokes a method.
459     * 
460     * @param opcode
461     *            the opcode of the type instruction to be visited. This opcode
462     *            is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or
463     *            INVOKEINTERFACE.
464     * @param owner
465     *            the internal name of the method's owner class (see
466     *            {@link Type#getInternalName() getInternalName}).
467     * @param name
468     *            the method's name.
469     * @param desc
470     *            the method's descriptor (see {@link Type Type}).
471     * @param itf
472     *            if the method's owner class is an interface.
473     */
474    public void visitMethodInsn(int opcode, String owner, String name,
475            String desc, boolean itf) {
476        if (api < Opcodes.ASM5) {
477            if (itf != (opcode == Opcodes.INVOKEINTERFACE)) {
478                throw new IllegalArgumentException(
479                        "INVOKESPECIAL/STATIC on interfaces require ASM 5");
480            }
481            visitMethodInsn(opcode, owner, name, desc);
482            return;
483        }
484        if (mv != null) {
485            mv.visitMethodInsn(opcode, owner, name, desc, itf);
486        }
487    }
488
489    /**
490     * Visits an invokedynamic instruction.
491     * 
492     * @param name
493     *            the method's name.
494     * @param desc
495     *            the method's descriptor (see {@link Type Type}).
496     * @param bsm
497     *            the bootstrap method.
498     * @param bsmArgs
499     *            the bootstrap method constant arguments. Each argument must be
500     *            an {@link Integer}, {@link Float}, {@link Long},
501     *            {@link Double}, {@link String}, {@link Type} or {@link Handle}
502     *            value. This method is allowed to modify the content of the
503     *            array so a caller should expect that this array may change.
504     */
505    public void visitInvokeDynamicInsn(String name, String desc, Handle bsm,
506            Object... bsmArgs) {
507        if (mv != null) {
508            mv.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
509        }
510    }
511
512    /**
513     * Visits a jump instruction. A jump instruction is an instruction that may
514     * jump to another instruction.
515     * 
516     * @param opcode
517     *            the opcode of the type instruction to be visited. This opcode
518     *            is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ,
519     *            IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE,
520     *            IF_ACMPEQ, IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.
521     * @param label
522     *            the operand of the instruction to be visited. This operand is
523     *            a label that designates the instruction to which the jump
524     *            instruction may jump.
525     */
526    public void visitJumpInsn(int opcode, Label label) {
527        if (mv != null) {
528            mv.visitJumpInsn(opcode, label);
529        }
530    }
531
532    /**
533     * Visits a label. A label designates the instruction that will be visited
534     * just after it.
535     * 
536     * @param label
537     *            a {@link Label Label} object.
538     */
539    public void visitLabel(Label label) {
540        if (mv != null) {
541            mv.visitLabel(label);
542        }
543    }
544
545    // -------------------------------------------------------------------------
546    // Special instructions
547    // -------------------------------------------------------------------------
548
549    /**
550     * Visits a LDC instruction. Note that new constant types may be added in
551     * future versions of the Java Virtual Machine. To easily detect new
552     * constant types, implementations of this method should check for
553     * unexpected constant types, like this:
554     * 
555     * <pre>
556     * if (cst instanceof Integer) {
557     *     // ...
558     * } else if (cst instanceof Float) {
559     *     // ...
560     * } else if (cst instanceof Long) {
561     *     // ...
562     * } else if (cst instanceof Double) {
563     *     // ...
564     * } else if (cst instanceof String) {
565     *     // ...
566     * } else if (cst instanceof Type) {
567     *     int sort = ((Type) cst).getSort();
568     *     if (sort == Type.OBJECT) {
569     *         // ...
570     *     } else if (sort == Type.ARRAY) {
571     *         // ...
572     *     } else if (sort == Type.METHOD) {
573     *         // ...
574     *     } else {
575     *         // throw an exception
576     *     }
577     * } else if (cst instanceof Handle) {
578     *     // ...
579     * } else {
580     *     // throw an exception
581     * }
582     * </pre>
583     * 
584     * @param cst
585     *            the constant to be loaded on the stack. This parameter must be
586     *            a non null {@link Integer}, a {@link Float}, a {@link Long}, a
587     *            {@link Double}, a {@link String}, a {@link Type} of OBJECT or
588     *            ARRAY sort for <tt>.class</tt> constants, for classes whose
589     *            version is 49.0, a {@link Type} of METHOD sort or a
590     *            {@link Handle} for MethodType and MethodHandle constants, for
591     *            classes whose version is 51.0.
592     */
593    public void visitLdcInsn(Object cst) {
594        if (mv != null) {
595            mv.visitLdcInsn(cst);
596        }
597    }
598
599    /**
600     * Visits an IINC instruction.
601     * 
602     * @param var
603     *            index of the local variable to be incremented.
604     * @param increment
605     *            amount to increment the local variable by.
606     */
607    public void visitIincInsn(int var, int increment) {
608        if (mv != null) {
609            mv.visitIincInsn(var, increment);
610        }
611    }
612
613    /**
614     * Visits a TABLESWITCH instruction.
615     * 
616     * @param min
617     *            the minimum key value.
618     * @param max
619     *            the maximum key value.
620     * @param dflt
621     *            beginning of the default handler block.
622     * @param labels
623     *            beginnings of the handler blocks. <tt>labels[i]</tt> is the
624     *            beginning of the handler block for the <tt>min + i</tt> key.
625     */
626    public void visitTableSwitchInsn(int min, int max, Label dflt,
627            Label... labels) {
628        if (mv != null) {
629            mv.visitTableSwitchInsn(min, max, dflt, labels);
630        }
631    }
632
633    /**
634     * Visits a LOOKUPSWITCH instruction.
635     * 
636     * @param dflt
637     *            beginning of the default handler block.
638     * @param keys
639     *            the values of the keys.
640     * @param labels
641     *            beginnings of the handler blocks. <tt>labels[i]</tt> is the
642     *            beginning of the handler block for the <tt>keys[i]</tt> key.
643     */
644    public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) {
645        if (mv != null) {
646            mv.visitLookupSwitchInsn(dflt, keys, labels);
647        }
648    }
649
650    /**
651     * Visits a MULTIANEWARRAY instruction.
652     * 
653     * @param desc
654     *            an array type descriptor (see {@link Type Type}).
655     * @param dims
656     *            number of dimensions of the array to allocate.
657     */
658    public void visitMultiANewArrayInsn(String desc, int dims) {
659        if (mv != null) {
660            mv.visitMultiANewArrayInsn(desc, dims);
661        }
662    }
663
664    /**
665     * Visits an annotation on an instruction. This method must be called just
666     * <i>after</i> the annotated instruction. It can be called several times
667     * for the same instruction.
668     * 
669     * @param typeRef
670     *            a reference to the annotated type. The sort of this type
671     *            reference must be {@link TypeReference#INSTANCEOF INSTANCEOF},
672     *            {@link TypeReference#NEW NEW},
673     *            {@link TypeReference#CONSTRUCTOR_REFERENCE
674     *            CONSTRUCTOR_REFERENCE}, {@link TypeReference#METHOD_REFERENCE
675     *            METHOD_REFERENCE}, {@link TypeReference#CAST CAST},
676     *            {@link TypeReference#CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT
677     *            CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT},
678     *            {@link TypeReference#METHOD_INVOCATION_TYPE_ARGUMENT
679     *            METHOD_INVOCATION_TYPE_ARGUMENT},
680     *            {@link TypeReference#CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT
681     *            CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT}, or
682     *            {@link TypeReference#METHOD_REFERENCE_TYPE_ARGUMENT
683     *            METHOD_REFERENCE_TYPE_ARGUMENT}. See {@link TypeReference}.
684     * @param typePath
685     *            the path to the annotated type argument, wildcard bound, array
686     *            element type, or static inner type within 'typeRef'. May be
687     *            <tt>null</tt> if the annotation targets 'typeRef' as a whole.
688     * @param desc
689     *            the class descriptor of the annotation class.
690     * @param visible
691     *            <tt>true</tt> if the annotation is visible at runtime.
692     * @return a visitor to visit the annotation values, or <tt>null</tt> if
693     *         this visitor is not interested in visiting this annotation.
694     */
695    public AnnotationVisitor visitInsnAnnotation(int typeRef,
696                                                 TypePath typePath, String desc, boolean visible) {
697        if (api < Opcodes.ASM5) {
698            throw new RuntimeException();
699        }
700        if (mv != null) {
701            return mv.visitInsnAnnotation(typeRef, typePath, desc, visible);
702        }
703        return null;
704    }
705
706    // -------------------------------------------------------------------------
707    // Exceptions table entries, debug information, max stack and max locals
708    // -------------------------------------------------------------------------
709
710    /**
711     * Visits a try catch block.
712     * 
713     * @param start
714     *            beginning of the exception handler's scope (inclusive).
715     * @param end
716     *            end of the exception handler's scope (exclusive).
717     * @param handler
718     *            beginning of the exception handler's code.
719     * @param type
720     *            internal name of the type of exceptions handled by the
721     *            handler, or <tt>null</tt> to catch any exceptions (for
722     *            "finally" blocks).
723     * @throws IllegalArgumentException
724     *             if one of the labels has already been visited by this visitor
725     *             (by the {@link #visitLabel visitLabel} method).
726     */
727    public void visitTryCatchBlock(Label start, Label end, Label handler,
728                                   String type) {
729        if (mv != null) {
730            mv.visitTryCatchBlock(start, end, handler, type);
731        }
732    }
733
734    /**
735     * Visits an annotation on an exception handler type. This method must be
736     * called <i>after</i> the {@link #visitTryCatchBlock} for the annotated
737     * exception handler. It can be called several times for the same exception
738     * handler.
739     * 
740     * @param typeRef
741     *            a reference to the annotated type. The sort of this type
742     *            reference must be {@link TypeReference#EXCEPTION_PARAMETER
743     *            EXCEPTION_PARAMETER}. See {@link TypeReference}.
744     * @param typePath
745     *            the path to the annotated type argument, wildcard bound, array
746     *            element type, or static inner type within 'typeRef'. May be
747     *            <tt>null</tt> if the annotation targets 'typeRef' as a whole.
748     * @param desc
749     *            the class descriptor of the annotation class.
750     * @param visible
751     *            <tt>true</tt> if the annotation is visible at runtime.
752     * @return a visitor to visit the annotation values, or <tt>null</tt> if
753     *         this visitor is not interested in visiting this annotation.
754     */
755    public AnnotationVisitor visitTryCatchAnnotation(int typeRef,
756                                                     TypePath typePath, String desc, boolean visible) {
757        if (api < Opcodes.ASM5) {
758            throw new RuntimeException();
759        }
760        if (mv != null) {
761            return mv.visitTryCatchAnnotation(typeRef, typePath, desc, visible);
762        }
763        return null;
764    }
765
766    /**
767     * Visits a local variable declaration.
768     * 
769     * @param name
770     *            the name of a local variable.
771     * @param desc
772     *            the type descriptor of this local variable.
773     * @param signature
774     *            the type signature of this local variable. May be
775     *            <tt>null</tt> if the local variable type does not use generic
776     *            types.
777     * @param start
778     *            the first instruction corresponding to the scope of this local
779     *            variable (inclusive).
780     * @param end
781     *            the last instruction corresponding to the scope of this local
782     *            variable (exclusive).
783     * @param index
784     *            the local variable's index.
785     * @throws IllegalArgumentException
786     *             if one of the labels has not already been visited by this
787     *             visitor (by the {@link #visitLabel visitLabel} method).
788     */
789    public void visitLocalVariable(String name, String desc, String signature,
790                                   Label start, Label end, int index) {
791        if (mv != null) {
792            mv.visitLocalVariable(name, desc, signature, start, end, index);
793        }
794    }
795
796    /**
797     * Visits an annotation on a local variable type.
798     * 
799     * @param typeRef
800     *            a reference to the annotated type. The sort of this type
801     *            reference must be {@link TypeReference#LOCAL_VARIABLE
802     *            LOCAL_VARIABLE} or {@link TypeReference#RESOURCE_VARIABLE
803     *            RESOURCE_VARIABLE}. See {@link TypeReference}.
804     * @param typePath
805     *            the path to the annotated type argument, wildcard bound, array
806     *            element type, or static inner type within 'typeRef'. May be
807     *            <tt>null</tt> if the annotation targets 'typeRef' as a whole.
808     * @param start
809     *            the fist instructions corresponding to the continuous ranges
810     *            that make the scope of this local variable (inclusive).
811     * @param end
812     *            the last instructions corresponding to the continuous ranges
813     *            that make the scope of this local variable (exclusive). This
814     *            array must have the same size as the 'start' array.
815     * @param index
816     *            the local variable's index in each range. This array must have
817     *            the same size as the 'start' array.
818     * @param desc
819     *            the class descriptor of the annotation class.
820     * @param visible
821     *            <tt>true</tt> if the annotation is visible at runtime.
822     * @return a visitor to visit the annotation values, or <tt>null</tt> if
823     *         this visitor is not interested in visiting this annotation.
824     */
825    public AnnotationVisitor visitLocalVariableAnnotation(int typeRef,
826                                                          TypePath typePath, Label[] start, Label[] end, int[] index,
827                                                          String desc, boolean visible) {
828        if (api < Opcodes.ASM5) {
829            throw new RuntimeException();
830        }
831        if (mv != null) {
832            return mv.visitLocalVariableAnnotation(typeRef, typePath, start,
833                    end, index, desc, visible);
834        }
835        return null;
836    }
837
838    /**
839     * Visits a line number declaration.
840     * 
841     * @param line
842     *            a line number. This number refers to the source file from
843     *            which the class was compiled.
844     * @param start
845     *            the first instruction corresponding to this line number.
846     * @throws IllegalArgumentException
847     *             if <tt>start</tt> has not already been visited by this
848     *             visitor (by the {@link #visitLabel visitLabel} method).
849     */
850    public void visitLineNumber(int line, Label start) {
851        if (mv != null) {
852            mv.visitLineNumber(line, start);
853        }
854    }
855
856    /**
857     * Visits the maximum stack size and the maximum number of local variables
858     * of the method.
859     * 
860     * @param maxStack
861     *            maximum stack size of the method.
862     * @param maxLocals
863     *            maximum number of local variables for the method.
864     */
865    public void visitMaxs(int maxStack, int maxLocals) {
866        if (mv != null) {
867            mv.visitMaxs(maxStack, maxLocals);
868        }
869    }
870
871    /**
872     * Visits the end of the method. This method, which is the last one to be
873     * called, is used to inform the visitor that all the annotations and
874     * attributes of the method have been visited.
875     */
876    public void visitEnd() {
877        if (mv != null) {
878            mv.visitEnd();
879        }
880    }
881}