1 /*
2  * Copyright (c) 2008, 2012, Oracle and/or its affiliates. All rights reserved.
3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4  *
5  * This code is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 only, as
7  * published by the Free Software Foundation.  Oracle designates this
8  * particular file as subject to the "Classpath" exception as provided
9  * by Oracle in the LICENSE file that accompanied this code.
10  *
11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
16  *
17  * You should have received a copy of the GNU General Public License version
18  * 2 along with this work; if not, write to the Free Software Foundation,
19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20  *
21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22  * or visit www.oracle.com if you need additional information or have any
23  * questions.
24  */
25 
26 package com.sun.tools.classfile;
27 
28 import java.util.Map;
29 
30 import com.sun.tools.classfile.ConstantPool.CONSTANT_Class_info;
31 import com.sun.tools.classfile.ConstantPool.CONSTANT_Dynamic_info;
32 import com.sun.tools.classfile.ConstantPool.CONSTANT_Double_info;
33 import com.sun.tools.classfile.ConstantPool.CONSTANT_Fieldref_info;
34 import com.sun.tools.classfile.ConstantPool.CONSTANT_Float_info;
35 import com.sun.tools.classfile.ConstantPool.CONSTANT_Integer_info;
36 import com.sun.tools.classfile.ConstantPool.CONSTANT_InterfaceMethodref_info;
37 import com.sun.tools.classfile.ConstantPool.CONSTANT_InvokeDynamic_info;
38 import com.sun.tools.classfile.ConstantPool.CONSTANT_Long_info;
39 import com.sun.tools.classfile.ConstantPool.CONSTANT_MethodHandle_info;
40 import com.sun.tools.classfile.ConstantPool.CONSTANT_MethodType_info;
41 import com.sun.tools.classfile.ConstantPool.CONSTANT_Methodref_info;
42 import com.sun.tools.classfile.ConstantPool.CONSTANT_Module_info;
43 import com.sun.tools.classfile.ConstantPool.CONSTANT_NameAndType_info;
44 import com.sun.tools.classfile.ConstantPool.CONSTANT_Package_info;
45 import com.sun.tools.classfile.ConstantPool.CONSTANT_String_info;
46 import com.sun.tools.classfile.ConstantPool.CONSTANT_Utf8_info;
47 import com.sun.tools.classfile.ConstantPool.CPInfo;
48 
49 /**
50  * Rewrites a class file using a map of translations.
51  *
52  *  <p><b>This is NOT part of any supported API.
53  *  If you write code that depends on this, you do so at your own risk.
54  *  This code and its internal interfaces are subject to change or
55  *  deletion without notice.</b>
56  */
57 public class ClassTranslator
58         implements ConstantPool.Visitor<ConstantPool.CPInfo,Map<Object,Object>> {
59     /**
60      * Create a new ClassFile from {@code cf}, such that for all entries
61      * {@code k&nbsp;-\&gt;&nbsp;v} in {@code translations},
62      * each occurrence of {@code k} in {@code cf} will be replaced by {@code v}.
63      * in
64      * @param cf the class file to be processed
65      * @param translations the set of translations to be applied
66      * @return a copy of {@code} with the values in {@code translations} substituted
67      */
translate(ClassFile cf, Map<Object,Object> translations)68     public ClassFile translate(ClassFile cf, Map<Object,Object> translations) {
69         ClassFile cf2 = (ClassFile) translations.get(cf);
70         if (cf2 == null) {
71             ConstantPool constant_pool2 = translate(cf.constant_pool, translations);
72             Field[] fields2 = translate(cf.fields, cf.constant_pool, translations);
73             Method[] methods2 = translateMethods(cf.methods, cf.constant_pool, translations);
74             Attributes attributes2 = translateAttributes(cf.attributes, cf.constant_pool,
75                     translations);
76 
77             if (constant_pool2 == cf.constant_pool &&
78                     fields2 == cf.fields &&
79                     methods2 == cf.methods &&
80                     attributes2 == cf.attributes)
81                 cf2 = cf;
82             else
83                 cf2 = new ClassFile(
84                         cf.magic,
85                         cf.minor_version,
86                         cf.major_version,
87                         constant_pool2,
88                         cf.access_flags,
89                         cf.this_class,
90                         cf.super_class,
91                         cf.interfaces,
92                         fields2,
93                         methods2,
94                         attributes2);
95             translations.put(cf, cf2);
96         }
97         return cf2;
98     }
99 
translate(ConstantPool cp, Map<Object,Object> translations)100     ConstantPool translate(ConstantPool cp, Map<Object,Object> translations) {
101         ConstantPool cp2 = (ConstantPool) translations.get(cp);
102         if (cp2 == null) {
103             ConstantPool.CPInfo[] pool2 = new ConstantPool.CPInfo[cp.size()];
104             boolean eq = true;
105             for (int i = 0; i < cp.size(); ) {
106                 ConstantPool.CPInfo cpInfo;
107                 try {
108                     cpInfo = cp.get(i);
109                 } catch (ConstantPool.InvalidIndex e) {
110                     throw new IllegalStateException(e);
111                 }
112                 ConstantPool.CPInfo cpInfo2 = translate(cpInfo, translations);
113                 eq &= (cpInfo == cpInfo2);
114                 pool2[i] = cpInfo2;
115                 if (cpInfo.getTag() != cpInfo2.getTag())
116                     throw new IllegalStateException();
117                 i += cpInfo.size();
118             }
119 
120             if (eq)
121                 cp2 = cp;
122             else
123                 cp2 = new ConstantPool(pool2);
124 
125             translations.put(cp, cp2);
126         }
127         return cp2;
128     }
129 
translate(ConstantPool.CPInfo cpInfo, Map<Object,Object> translations)130     ConstantPool.CPInfo translate(ConstantPool.CPInfo cpInfo, Map<Object,Object> translations) {
131         ConstantPool.CPInfo cpInfo2 = (ConstantPool.CPInfo) translations.get(cpInfo);
132         if (cpInfo2 == null) {
133             cpInfo2 = cpInfo.accept(this, translations);
134             translations.put(cpInfo, cpInfo2);
135         }
136         return cpInfo2;
137     }
138 
translate(Field[] fields, ConstantPool constant_pool, Map<Object,Object> translations)139     Field[] translate(Field[] fields, ConstantPool constant_pool, Map<Object,Object> translations) {
140         Field[] fields2 = (Field[]) translations.get(fields);
141         if (fields2 == null) {
142             fields2 = new Field[fields.length];
143             for (int i = 0; i < fields.length; i++)
144                 fields2[i] = translate(fields[i], constant_pool, translations);
145             if (equal(fields, fields2))
146                 fields2 = fields;
147             translations.put(fields, fields2);
148         }
149         return fields2;
150     }
151 
translate(Field field, ConstantPool constant_pool, Map<Object,Object> translations)152     Field translate(Field field, ConstantPool constant_pool, Map<Object,Object> translations) {
153         Field field2 = (Field) translations.get(field);
154         if (field2 == null) {
155             Attributes attributes2 = translateAttributes(field.attributes, constant_pool,
156                     translations);
157 
158             if (attributes2 == field.attributes)
159                 field2 = field;
160             else
161                 field2 = new Field(
162                         field.access_flags,
163                         field.name_index,
164                         field.descriptor,
165                         attributes2);
166             translations.put(field, field2);
167         }
168         return field2;
169     }
170 
translateMethods(Method[] methods, ConstantPool constant_pool, Map<Object,Object> translations)171     Method[] translateMethods(Method[] methods, ConstantPool constant_pool, Map<Object,Object> translations) {
172         Method[] methods2 = (Method[]) translations.get(methods);
173         if (methods2 == null) {
174             methods2 = new Method[methods.length];
175             for (int i = 0; i < methods.length; i++)
176                 methods2[i] = translate(methods[i], constant_pool, translations);
177             if (equal(methods, methods2))
178                 methods2 = methods;
179             translations.put(methods, methods2);
180         }
181         return methods2;
182     }
183 
translate(Method method, ConstantPool constant_pool, Map<Object,Object> translations)184     Method translate(Method method, ConstantPool constant_pool, Map<Object,Object> translations) {
185         Method method2 = (Method) translations.get(method);
186         if (method2 == null) {
187             Attributes attributes2 = translateAttributes(method.attributes, constant_pool,
188                     translations);
189 
190             if (attributes2 == method.attributes)
191                 method2 = method;
192             else
193                 method2 = new Method(
194                         method.access_flags,
195                         method.name_index,
196                         method.descriptor,
197                         attributes2);
198             translations.put(method, method2);
199         }
200         return method2;
201     }
202 
translateAttributes(Attributes attributes, ConstantPool constant_pool, Map<Object,Object> translations)203     Attributes translateAttributes(Attributes attributes,
204             ConstantPool constant_pool, Map<Object,Object> translations) {
205         Attributes attributes2 = (Attributes) translations.get(attributes);
206         if (attributes2 == null) {
207             Attribute[] attrArray2 = new Attribute[attributes.size()];
208             ConstantPool constant_pool2 = translate(constant_pool, translations);
209             boolean attrsEqual = true;
210             for (int i = 0; i < attributes.size(); i++) {
211                 Attribute attr = attributes.get(i);
212                 Attribute attr2 = translate(attr, translations);
213                 if (attr2 != attr)
214                     attrsEqual = false;
215                 attrArray2[i] = attr2;
216             }
217             if ((constant_pool2 == constant_pool) && attrsEqual)
218                 attributes2 = attributes;
219             else
220                 attributes2 = new Attributes(constant_pool2, attrArray2);
221             translations.put(attributes, attributes2);
222         }
223         return attributes2;
224     }
225 
translate(Attribute attribute, Map<Object,Object> translations)226     Attribute translate(Attribute attribute, Map<Object,Object> translations) {
227         Attribute attribute2 = (Attribute) translations.get(attribute);
228         if (attribute2 == null) {
229             attribute2 = attribute; // don't support translation within attributes yet
230                                     // (what about Code attribute)
231             translations.put(attribute, attribute2);
232         }
233         return attribute2;
234     }
235 
equal(T[] a1, T[] a2)236     private static <T> boolean equal(T[] a1, T[] a2) {
237         if (a1 == null || a2 == null)
238             return (a1 == a2);
239         if (a1.length != a2.length)
240             return false;
241         for (int i = 0; i < a1.length; i++) {
242             if (a1[i] != a2[i])
243                 return false;
244         }
245         return true;
246     }
247 
248     @Override
visitClass(CONSTANT_Class_info info, Map<Object, Object> translations)249     public CPInfo visitClass(CONSTANT_Class_info info, Map<Object, Object> translations) {
250         CONSTANT_Class_info info2 = (CONSTANT_Class_info) translations.get(info);
251         if (info2 == null) {
252             ConstantPool cp2 = translate(info.cp, translations);
253             if (cp2 == info.cp)
254                 info2 = info;
255             else
256                 info2 = new CONSTANT_Class_info(cp2, info.name_index);
257             translations.put(info, info2);
258         }
259         return info;
260     }
261 
262     @Override
visitDouble(CONSTANT_Double_info info, Map<Object, Object> translations)263     public CPInfo visitDouble(CONSTANT_Double_info info, Map<Object, Object> translations) {
264         CONSTANT_Double_info info2 = (CONSTANT_Double_info) translations.get(info);
265         if (info2 == null) {
266             info2 = info;
267             translations.put(info, info2);
268         }
269         return info;
270     }
271 
272     @Override
visitFieldref(CONSTANT_Fieldref_info info, Map<Object, Object> translations)273     public CPInfo visitFieldref(CONSTANT_Fieldref_info info, Map<Object, Object> translations) {
274         CONSTANT_Fieldref_info info2 = (CONSTANT_Fieldref_info) translations.get(info);
275         if (info2 == null) {
276             ConstantPool cp2 = translate(info.cp, translations);
277             if (cp2 == info.cp)
278                 info2 = info;
279             else
280                 info2 = new CONSTANT_Fieldref_info(cp2, info.class_index, info.name_and_type_index);
281             translations.put(info, info2);
282         }
283         return info;
284     }
285 
286     @Override
visitFloat(CONSTANT_Float_info info, Map<Object, Object> translations)287     public CPInfo visitFloat(CONSTANT_Float_info info, Map<Object, Object> translations) {
288         CONSTANT_Float_info info2 = (CONSTANT_Float_info) translations.get(info);
289         if (info2 == null) {
290             info2 = info;
291             translations.put(info, info2);
292         }
293         return info;
294     }
295 
296     @Override
visitInteger(CONSTANT_Integer_info info, Map<Object, Object> translations)297     public CPInfo visitInteger(CONSTANT_Integer_info info, Map<Object, Object> translations) {
298         CONSTANT_Integer_info info2 = (CONSTANT_Integer_info) translations.get(info);
299         if (info2 == null) {
300             info2 = info;
301             translations.put(info, info2);
302         }
303         return info;
304     }
305 
306     @Override
visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, Map<Object, Object> translations)307     public CPInfo visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, Map<Object, Object> translations) {
308         CONSTANT_InterfaceMethodref_info info2 = (CONSTANT_InterfaceMethodref_info) translations.get(info);
309         if (info2 == null) {
310             ConstantPool cp2 = translate(info.cp, translations);
311             if (cp2 == info.cp)
312                 info2 = info;
313             else
314                 info2 = new CONSTANT_InterfaceMethodref_info(cp2, info.class_index, info.name_and_type_index);
315             translations.put(info, info2);
316         }
317         return info;
318     }
319 
320     @Override
visitInvokeDynamic(CONSTANT_InvokeDynamic_info info, Map<Object, Object> translations)321     public CPInfo visitInvokeDynamic(CONSTANT_InvokeDynamic_info info, Map<Object, Object> translations) {
322         CONSTANT_InvokeDynamic_info info2 = (CONSTANT_InvokeDynamic_info) translations.get(info);
323         if (info2 == null) {
324             ConstantPool cp2 = translate(info.cp, translations);
325             if (cp2 == info.cp) {
326                 info2 = info;
327             } else {
328                 info2 = new CONSTANT_InvokeDynamic_info(cp2, info.bootstrap_method_attr_index, info.name_and_type_index);
329             }
330             translations.put(info, info2);
331         }
332         return info;
333     }
334 
visitDynamicConstant(CONSTANT_Dynamic_info info, Map<Object, Object> translations)335     public CPInfo visitDynamicConstant(CONSTANT_Dynamic_info info, Map<Object, Object> translations) {
336         CONSTANT_Dynamic_info info2 = (CONSTANT_Dynamic_info) translations.get(info);
337         if (info2 == null) {
338             ConstantPool cp2 = translate(info.cp, translations);
339             if (cp2 == info.cp) {
340                 info2 = info;
341             } else {
342                 info2 = new CONSTANT_Dynamic_info(cp2, info.bootstrap_method_attr_index, info.name_and_type_index);
343             }
344             translations.put(info, info2);
345         }
346         return info;
347     }
348 
349     @Override
visitLong(CONSTANT_Long_info info, Map<Object, Object> translations)350     public CPInfo visitLong(CONSTANT_Long_info info, Map<Object, Object> translations) {
351         CONSTANT_Long_info info2 = (CONSTANT_Long_info) translations.get(info);
352         if (info2 == null) {
353             info2 = info;
354             translations.put(info, info2);
355         }
356         return info;
357     }
358 
359     @Override
visitMethodref(CONSTANT_Methodref_info info, Map<Object, Object> translations)360     public CPInfo visitMethodref(CONSTANT_Methodref_info info, Map<Object, Object> translations) {
361         CONSTANT_Methodref_info info2 = (CONSTANT_Methodref_info) translations.get(info);
362         if (info2 == null) {
363             ConstantPool cp2 = translate(info.cp, translations);
364             if (cp2 == info.cp)
365                 info2 = info;
366             else
367                 info2 = new CONSTANT_Methodref_info(cp2, info.class_index, info.name_and_type_index);
368             translations.put(info, info2);
369         }
370         return info;
371     }
372 
373     @Override
visitMethodHandle(CONSTANT_MethodHandle_info info, Map<Object, Object> translations)374     public CPInfo visitMethodHandle(CONSTANT_MethodHandle_info info, Map<Object, Object> translations) {
375         CONSTANT_MethodHandle_info info2 = (CONSTANT_MethodHandle_info) translations.get(info);
376         if (info2 == null) {
377             ConstantPool cp2 = translate(info.cp, translations);
378             if (cp2 == info.cp) {
379                 info2 = info;
380             } else {
381                 info2 = new CONSTANT_MethodHandle_info(cp2, info.reference_kind, info.reference_index);
382             }
383             translations.put(info, info2);
384         }
385         return info;
386     }
387 
388     @Override
visitMethodType(CONSTANT_MethodType_info info, Map<Object, Object> translations)389     public CPInfo visitMethodType(CONSTANT_MethodType_info info, Map<Object, Object> translations) {
390         CONSTANT_MethodType_info info2 = (CONSTANT_MethodType_info) translations.get(info);
391         if (info2 == null) {
392             ConstantPool cp2 = translate(info.cp, translations);
393             if (cp2 == info.cp) {
394                 info2 = info;
395             } else {
396                 info2 = new CONSTANT_MethodType_info(cp2, info.descriptor_index);
397             }
398             translations.put(info, info2);
399         }
400         return info;
401     }
402 
403     @Override
visitModule(CONSTANT_Module_info info, Map<Object, Object> translations)404     public CPInfo visitModule(CONSTANT_Module_info info, Map<Object, Object> translations) {
405         CONSTANT_Module_info info2 = (CONSTANT_Module_info) translations.get(info);
406         if (info2 == null) {
407             ConstantPool cp2 = translate(info.cp, translations);
408             if (cp2 == info.cp)
409                 info2 = info;
410             else
411                 info2 = new CONSTANT_Module_info(cp2, info.name_index);
412             translations.put(info, info2);
413         }
414         return info;
415     }
416 
417     @Override
visitNameAndType(CONSTANT_NameAndType_info info, Map<Object, Object> translations)418     public CPInfo visitNameAndType(CONSTANT_NameAndType_info info, Map<Object, Object> translations) {
419         CONSTANT_NameAndType_info info2 = (CONSTANT_NameAndType_info) translations.get(info);
420         if (info2 == null) {
421             ConstantPool cp2 = translate(info.cp, translations);
422             if (cp2 == info.cp)
423                 info2 = info;
424             else
425                 info2 = new CONSTANT_NameAndType_info(cp2, info.name_index, info.type_index);
426             translations.put(info, info2);
427         }
428         return info;
429     }
430 
431     @Override
visitPackage(CONSTANT_Package_info info, Map<Object, Object> translations)432     public CPInfo visitPackage(CONSTANT_Package_info info, Map<Object, Object> translations) {
433         CONSTANT_Package_info info2 = (CONSTANT_Package_info) translations.get(info);
434         if (info2 == null) {
435             ConstantPool cp2 = translate(info.cp, translations);
436             if (cp2 == info.cp)
437                 info2 = info;
438             else
439                 info2 = new CONSTANT_Package_info(cp2, info.name_index);
440             translations.put(info, info2);
441         }
442         return info;
443     }
444 
445     @Override
visitString(CONSTANT_String_info info, Map<Object, Object> translations)446     public CPInfo visitString(CONSTANT_String_info info, Map<Object, Object> translations) {
447         CONSTANT_String_info info2 = (CONSTANT_String_info) translations.get(info);
448         if (info2 == null) {
449             ConstantPool cp2 = translate(info.cp, translations);
450             if (cp2 == info.cp)
451                 info2 = info;
452             else
453                 info2 = new CONSTANT_String_info(cp2, info.string_index);
454             translations.put(info, info2);
455         }
456         return info;
457     }
458 
459     @Override
visitUtf8(CONSTANT_Utf8_info info, Map<Object, Object> translations)460     public CPInfo visitUtf8(CONSTANT_Utf8_info info, Map<Object, Object> translations) {
461         CONSTANT_Utf8_info info2 = (CONSTANT_Utf8_info) translations.get(info);
462         if (info2 == null) {
463             info2 = info;
464             translations.put(info, info2);
465         }
466         return info;
467     }
468 
469 }
470