TraceMethodVisitor


1   /***
2    * ASM: a very small and fast Java bytecode manipulation framework
3    * Copyright (c) 2000-2005 INRIA, France Telecom
4    * All rights reserved.
5    *
6    * Redistribution and use in source and binary forms, with or without
7    * modification, are permitted provided that the following conditions
8    * are met:
9    * 1. Redistributions of source code must retain the above copyright
10   *    notice, this list of conditions and the following disclaimer.
11   * 2. Redistributions in binary form must reproduce the above copyright
12   *    notice, this list of conditions and the following disclaimer in the
13   *    documentation and/or other materials provided with the distribution.
14   * 3. Neither the name of the copyright holders nor the names of its
15   *    contributors may be used to endorse or promote products derived from
16   *    this software without specific prior written permission.
17   *
18   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28   * THE POSSIBILITY OF SUCH DAMAGE.
29   */
30  package com.tc.asm.util;
31  
32  import com.tc.asm.AnnotationVisitor;
33  import com.tc.asm.Attribute;
34  import com.tc.asm.MethodVisitor;
35  import com.tc.asm.Label;
36  import com.tc.asm.Opcodes;
37  import com.tc.asm.Type;
38  import com.tc.asm.signature.SignatureReader;
39  import com.tc.asm.util.attrs.Traceable;
40  
41  import java.util.HashMap  ;
42  
43  /**
44   * A {@link MethodVisitor} that prints a disassembled view of the methods it
45   * visits.
46   * 
47   * @author Eric Bruneton
48   */
49  public class TraceMethodVisitor extends TraceAbstractVisitor implements
50          MethodVisitor
51  {
52  
53      /**
54       * The {@link MethodVisitor} to which this visitor delegates calls. May be
55       * <tt>null</tt>.
56       */
57      protected MethodVisitor mv;
58  
59      /**
60       * Tab for bytecode instructions.
61       */
62      protected String   tab2 = "    ";
63  
64      /**
65       * Tab for table and lookup switch instructions.
66       */
67      protected String   tab3 = "      ";
68  
69      /**
70       * Tab for labels.
71       */
72      protected String   ltab = "   ";
73  
74      /**
75       * The label names. This map associate String values to Label keys.
76       */
77      protected final HashMap   labelNames;
78  
79      /**
80       * Constructs a new {@link TraceMethodVisitor}.
81       */
82      public TraceMethodVisitor() {
83          this(null);
84      }
85  
86      /**
87       * Constructs a new {@link TraceMethodVisitor}.
88       * 
89       * @param mv the {@link MethodVisitor} to which this visitor delegates
90       *        calls. May be <tt>null</tt>.
91       */
92      public TraceMethodVisitor(final MethodVisitor mv) {
93          this.labelNames = new HashMap  ();
94          this.mv = mv;
95      }
96  
97      // ------------------------------------------------------------------------
98      // Implementation of the MethodVisitor interface
99      // ------------------------------------------------------------------------
100 
101     public AnnotationVisitor visitAnnotation(
102         final String   desc,
103         final boolean visible)
104     {
105         AnnotationVisitor av = super.visitAnnotation(desc, visible);
106         if (mv != null) {
107             ((TraceAnnotationVisitor) av).av = mv.visitAnnotation(desc, visible);
108         }
109         return av;
110     }
111 
112     public void visitAttribute(final Attribute attr) {
113         buf.setLength(0);
114         buf.append(tab).append("ATTRIBUTE ");
115         appendDescriptor(-1, attr.type);
116 
117         if (attr instanceof Traceable) {
118             ((Traceable) attr).trace(buf, labelNames);
119         } else {
120             buf.append(" : ").append(attr.toString()).append("\n");
121         }
122 
123         text.add(buf.toString());
124         if (mv != null) {
125             mv.visitAttribute(attr);
126         }
127     }
128 
129     public AnnotationVisitor visitAnnotationDefault() {
130         text.add(tab2 + "default=");
131         TraceAnnotationVisitor tav = new TraceAnnotationVisitor();
132         text.add(tav.getText());
133         text.add("\n");
134         if (mv != null) {
135             tav.av = mv.visitAnnotationDefault();
136         }
137         return tav;
138     }
139 
140     public AnnotationVisitor visitParameterAnnotation(
141         final int parameter,
142         final String   desc,
143         final boolean visible)
144     {
145         buf.setLength(0);
146         buf.append(tab2).append('@');
147         appendDescriptor(FIELD_DESCRIPTOR, desc);
148         buf.append('(');
149         text.add(buf.toString());
150         TraceAnnotationVisitor tav = new TraceAnnotationVisitor();
151         text.add(tav.getText());
152         text.add(visible ? ") // parameter " : ") // invisible, parameter ");
153         text.add(new Integer  (parameter));
154         text.add("\n");
155         if (mv != null) {
156             tav.av = mv.visitParameterAnnotation(parameter, desc, visible);
157         }
158         return tav;
159     }
160 
161     public void visitCode() {
162         if (mv != null) {
163             mv.visitCode();
164         }
165     }
166 
167     public void visitInsn(final int opcode) {
168         buf.setLength(0);
169         buf.append(tab2).append(OPCODES[opcode]).append('\n');
170         text.add(buf.toString());
171 
172         if (mv != null) {
173             mv.visitInsn(opcode);
174         }
175     }
176 
177     public void visitIntInsn(final int opcode, final int operand) {
178         buf.setLength(0);
179         buf.append(tab2)
180                 .append(OPCODES[opcode])
181                 .append(' ')
182                 .append(opcode == Opcodes.NEWARRAY
183                         ? TYPES[operand]
184                         : Integer.toString(operand))
185                 .append('\n');
186         text.add(buf.toString());
187 
188         if (mv != null) {
189             mv.visitIntInsn(opcode, operand);
190         }
191     }
192 
193     public void visitVarInsn(final int opcode, final int var) {
194         buf.setLength(0);
195         buf.append(tab2)
196                 .append(OPCODES[opcode])
197                 .append(' ')
198                 .append(var)
199                 .append('\n');
200         text.add(buf.toString());
201 
202         if (mv != null) {
203             mv.visitVarInsn(opcode, var);
204         }
205     }
206 
207     public void visitTypeInsn(final int opcode, final String   desc) {
208         buf.setLength(0);
209         buf.append(tab2).append(OPCODES[opcode]).append(' ');
210         if (desc.startsWith("[")) {
211             appendDescriptor(FIELD_DESCRIPTOR, desc);
212         } else {
213             appendDescriptor(INTERNAL_NAME, desc);
214         }
215         buf.append('\n');
216         text.add(buf.toString());
217 
218         if (mv != null) {
219             mv.visitTypeInsn(opcode, desc);
220         }
221     }
222 
223     public void visitFieldInsn(
224         final int opcode,
225         final String   owner,
226         final String   name,
227         final String   desc)
228     {
229         buf.setLength(0);
230         buf.append(tab2).append(OPCODES[opcode]).append(' ');
231         appendDescriptor(INTERNAL_NAME, owner);
232         buf.append('.').append(name).append(" : ");
233         appendDescriptor(FIELD_DESCRIPTOR, desc);
234         buf.append('\n');
235         text.add(buf.toString());
236 
237         if (mv != null) {
238             mv.visitFieldInsn(opcode, owner, name, desc);
239         }
240     }
241 
242     public void visitMethodInsn(
243         final int opcode,
244         final String   owner,
245         final String   name,
246         final String   desc)
247     {
248         buf.setLength(0);
249         buf.append(tab2).append(OPCODES[opcode]).append(' ');
250         appendDescriptor(INTERNAL_NAME, owner);
251         buf.append('.').append(name).append(' ');
252         appendDescriptor(METHOD_DESCRIPTOR, desc);
253         buf.append('\n');
254         text.add(buf.toString());
255 
256         if (mv != null) {
257             mv.visitMethodInsn(opcode, owner, name, desc);
258         }
259     }
260 
261     public void visitJumpInsn(final int opcode, final Label label) {
262         buf.setLength(0);
263         buf.append(tab2).append(OPCODES[opcode]).append(' ');
264         appendLabel(label);
265         buf.append('\n');
266         text.add(buf.toString());
267 
268         if (mv != null) {
269             mv.visitJumpInsn(opcode, label);
270         }
271     }
272 
273     public void visitLabel(final Label label) {
274         buf.setLength(0);
275         buf.append(ltab);
276         appendLabel(label);
277         buf.append('\n');
278         text.add(buf.toString());
279 
280         if (mv != null) {
281             mv.visitLabel(label);
282         }
283     }
284 
285     public void visitLdcInsn(final Object   cst) {
286         buf.setLength(0);
287         buf.append(tab2).append("LDC ");
288         if (cst instanceof String  ) {
289             AbstractVisitor.appendString(buf, (String  ) cst);
290         } else if (cst instanceof Type) {
291             buf.append(((Type) cst).getDescriptor() + ".class");
292         } else {
293             buf.append(cst);
294         }
295         buf.append('\n');
296         text.add(buf.toString());
297 
298         if (mv != null) {
299             mv.visitLdcInsn(cst);
300         }
301     }
302 
303     public void visitIincInsn(final int var, final int increment) {
304         buf.setLength(0);
305         buf.append(tab2)
306                 .append("IINC ")
307                 .append(var)
308                 .append(' ')
309                 .append(increment)
310                 .append('\n');
311         text.add(buf.toString());
312 
313         if (mv != null) {
314             mv.visitIincInsn(var, increment);
315         }
316     }
317 
318     public void visitTableSwitchInsn(
319         final int min,
320         final int max,
321         final Label dflt,
322         final Label labels[])
323     {
324         buf.setLength(0);
325         buf.append(tab2).append("TABLESWITCH\n");
326         for (int i = 0; i < labels.length; ++i) {
327             buf.append(tab3).append(min + i).append(": ");
328             appendLabel(labels[i]);
329             buf.append('\n');
330         }
331         buf.append(tab3).append("default: ");
332         appendLabel(dflt);
333         buf.append('\n');
334         text.add(buf.toString());
335 
336         if (mv != null) {
337             mv.visitTableSwitchInsn(min, max, dflt, labels);
338         }
339     }
340 
341     public void visitLookupSwitchInsn(
342         final Label dflt,
343         final int keys[],
344         final Label labels[])
345     {
346         buf.setLength(0);
347         buf.append(tab2).append("LOOKUPSWITCH\n");
348         for (int i = 0; i < labels.length; ++i) {
349             buf.append(tab3).append(keys[i]).append(": ");
350             appendLabel(labels[i]);
351             buf.append('\n');
352         }
353         buf.append(tab3).append("default: ");
354         appendLabel(dflt);
355         buf.append('\n');
356         text.add(buf.toString());
357 
358         if (mv != null) {
359             mv.visitLookupSwitchInsn(dflt, keys, labels);
360         }
361     }
362 
363     public void visitMultiANewArrayInsn(final String   desc, final int dims) {
364         buf.setLength(0);
365         buf.append(tab2).append("MULTIANEWARRAY ");
366         appendDescriptor(FIELD_DESCRIPTOR, desc);
367         buf.append(' ').append(dims).append('\n');
368         text.add(buf.toString());
369 
370         if (mv != null) {
371             mv.visitMultiANewArrayInsn(desc, dims);
372         }
373     }
374 
375     public void visitTryCatchBlock(
376         final Label start,
377         final Label end,
378         final Label handler,
379         final String   type)
380     {
381         buf.setLength(0);
382         buf.append(tab2).append("TRYCATCHBLOCK ");
383         appendLabel(start);
384         buf.append(' ');
385         appendLabel(end);
386         buf.append(' ');
387         appendLabel(handler);
388         buf.append(' ');
389         appendDescriptor(INTERNAL_NAME, type);
390         buf.append('\n');
391         text.add(buf.toString());
392 
393         if (mv != null) {
394             mv.visitTryCatchBlock(start, end, handler, type);
395         }
396     }
397 
398     public void visitLocalVariable(
399         final String   name,
400         final String   desc,
401         final String   signature,
402         final Label start,
403         final Label end,
404         final int index)
405     {
406         buf.setLength(0);
407         buf.append(tab2).append("LOCALVARIABLE ").append(name).append(' ');
408         appendDescriptor(FIELD_DESCRIPTOR, desc);
409         buf.append(' ');
410         appendLabel(start);
411         buf.append(' ');
412         appendLabel(end);
413         buf.append(' ').append(index).append('\n');
414 
415         if (signature != null) {
416             buf.append(tab2);
417             appendDescriptor(FIELD_SIGNATURE, signature);
418 
419             TraceSignatureVisitor sv = new TraceSignatureVisitor(0);
420             SignatureReader r = new SignatureReader(signature);
421             r.acceptType(sv);
422             buf.append(tab2)
423                     .append("// declaration: ")
424                     .append(sv.getDeclaration())
425                     .append('\n');
426         }
427         text.add(buf.toString());
428 
429         if (mv != null) {
430             mv.visitLocalVariable(name, desc, signature, start, end, index);
431         }
432     }
433 
434     public void visitLineNumber(final int line, final Label start) {
435         buf.setLength(0);
436         buf.append(tab2).append("LINENUMBER ").append(line).append(' ');
437         appendLabel(start);
438         buf.append('\n');
439         text.add(buf.toString());
440 
441         if (mv != null) {
442             mv.visitLineNumber(line, start);
443         }
444     }
445 
446     public void visitMaxs(final int maxStack, final int maxLocals) {
447         buf.setLength(0);
448         buf.append(tab2).append("MAXSTACK = ").append(maxStack).append('\n');
449         text.add(buf.toString());
450 
451         buf.setLength(0);
452         buf.append(tab2).append("MAXLOCALS = ").append(maxLocals).append('\n');
453         text.add(buf.toString());
454 
455         if (mv != null) {
456             mv.visitMaxs(maxStack, maxLocals);
457         }
458     }
459 
460     public void visitEnd() {
461         super.visitEnd();
462 
463         if (mv != null) {
464             mv.visitEnd();
465         }
466     }
467 
468     // ------------------------------------------------------------------------
469     // Utility methods
470     // ------------------------------------------------------------------------
471 
472     /**
473      * Appends the name of the given label to {@link #buf buf}. Creates a new
474      * label name if the given label does not yet have one.
475      * 
476      * @param l a label.
477      */
478     public void appendLabel(final Label l) {
479         String   name = (String  ) labelNames.get(l);
480         if (name == null) {
481             name = "L" + labelNames.size();
482             labelNames.put(l, name);
483         }
484         buf.append(name);
485     }
486 }
487
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