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_Double_info;

    32 import com.sun.tools.classfile.ConstantPool.CONSTANT_Fieldref_info;

    33 import com.sun.tools.classfile.ConstantPool.CONSTANT_Float_info;

    34 import com.sun.tools.classfile.ConstantPool.CONSTANT_Integer_info;

    35 import com.sun.tools.classfile.ConstantPool.CONSTANT_InterfaceMethodref_info;

    36 import com.sun.tools.classfile.ConstantPool.CONSTANT_InvokeDynamic_info;

    37 import com.sun.tools.classfile.ConstantPool.CONSTANT_Long_info;

    38 import com.sun.tools.classfile.ConstantPool.CONSTANT_MethodHandle_info;

    39 import com.sun.tools.classfile.ConstantPool.CONSTANT_MethodType_info;

    40 import com.sun.tools.classfile.ConstantPool.CONSTANT_Methodref_info;

    41 import com.sun.tools.classfile.ConstantPool.CONSTANT_NameAndType_info;

    42 import com.sun.tools.classfile.ConstantPool.CONSTANT_String_info;

    43 import com.sun.tools.classfile.ConstantPool.CONSTANT_Utf8_info;

    44 import com.sun.tools.classfile.ConstantPool.CPInfo;

    45 

    46 /**

    47  * Rewrites a class file using a map of translations.

    48  *

    49  *  <p><b>This is NOT part of any supported API.

    50  *  If you write code that depends on this, you do so at your own risk.

    51  *  This code and its internal interfaces are subject to change or

    52  *  deletion without notice.</b>

    53  */

    54 public class ClassTranslator

    55         implements ConstantPool.Visitor<ConstantPool.CPInfo,Map<Object,Object>> {

    56     /**

    57      * Create a new ClassFile from {@code cf}, such that for all entries

    58      * {@code k -\> v} in {@code translations},

    59      * each occurrence of {@code k} in {@code cf} will be replaced by {@code v}.

    60      * in

    61      * @param cf the class file to be processed

    62      * @param translations the set of translations to be applied

    63      * @return a copy of {@code} with the values in {@code translations} substituted

    64      */

    65     public ClassFile translate(ClassFile cf, Map<Object,Object> translations) {

    66         ClassFile cf2 = (ClassFile) translations.get(cf);

    67         if (cf2 == null) {

    68             ConstantPool constant_pool2 = translate(cf.constant_pool, translations);

    69             Field[] fields2 = translate(cf.fields, cf.constant_pool, translations);

    70             Method[] methods2 = translateMethods(cf.methods, cf.constant_pool, translations);

    71             Attributes attributes2 = translateAttributes(cf.attributes, cf.constant_pool,

    72                     translations);

    73 

    74             if (constant_pool2 == cf.constant_pool &&

    75                     fields2 == cf.fields &&

    76                     methods2 == cf.methods &&

    77                     attributes2 == cf.attributes)

    78                 cf2 = cf;

    79             else

    80                 cf2 = new ClassFile(

    81                         cf.magic,

    82                         cf.minor_version,

    83                         cf.major_version,

    84                         constant_pool2,

    85                         cf.access_flags,

    86                         cf.this_class,

    87                         cf.super_class,

    88                         cf.interfaces,

    89                         fields2,

    90                         methods2,

    91                         attributes2);

    92             translations.put(cf, cf2);

    93         }

    94         return cf2;

    95     }

    96 

    97     ConstantPool translate(ConstantPool cp, Map<Object,Object> translations) {

    98         ConstantPool cp2 = (ConstantPool) translations.get(cp);

    99         if (cp2 == null) {

   100             ConstantPool.CPInfo[] pool2 = new ConstantPool.CPInfo[cp.size()];

   101             boolean eq = true;

   102             for (int i = 0; i < cp.size(); ) {

   103                 ConstantPool.CPInfo cpInfo;

   104                 try {

   105                     cpInfo = cp.get(i);

   106                 } catch (ConstantPool.InvalidIndex e) {

   107                     throw new IllegalStateException(e);

   108                 }

   109                 ConstantPool.CPInfo cpInfo2 = translate(cpInfo, translations);

   110                 eq &= (cpInfo == cpInfo2);

   111                 pool2[i] = cpInfo2;

   112                 if (cpInfo.getTag() != cpInfo2.getTag())

   113                     throw new IllegalStateException();

   114                 i += cpInfo.size();

   115             }

   116 

   117             if (eq)

   118                 cp2 = cp;

   119             else

   120                 cp2 = new ConstantPool(pool2);

   121 

   122             translations.put(cp, cp2);

   123         }

   124         return cp2;

   125     }

   126 

   127     ConstantPool.CPInfo translate(ConstantPool.CPInfo cpInfo, Map<Object,Object> translations) {

   128         ConstantPool.CPInfo cpInfo2 = (ConstantPool.CPInfo) translations.get(cpInfo);

   129         if (cpInfo2 == null) {

   130             cpInfo2 = cpInfo.accept(this, translations);

   131             translations.put(cpInfo, cpInfo2);

   132         }

   133         return cpInfo2;

   134     }

   135 

   136     Field[] translate(Field[] fields, ConstantPool constant_pool, Map<Object,Object> translations) {

   137         Field[] fields2 = (Field[]) translations.get(fields);

   138         if (fields2 == null) {

   139             fields2 = new Field[fields.length];

   140             for (int i = 0; i < fields.length; i++)

   141                 fields2[i] = translate(fields[i], constant_pool, translations);

   142             if (equal(fields, fields2))

   143                 fields2 = fields;

   144             translations.put(fields, fields2);

   145         }

   146         return fields2;

   147     }

   148 

   149     Field translate(Field field, ConstantPool constant_pool, Map<Object,Object> translations) {

   150         Field field2 = (Field) translations.get(field);

   151         if (field2 == null) {

   152             Attributes attributes2 = translateAttributes(field.attributes, constant_pool,

   153                     translations);

   154 

   155             if (attributes2 == field.attributes)

   156                 field2 = field;

   157             else

   158                 field2 = new Field(

   159                         field.access_flags,

   160                         field.name_index,

   161                         field.descriptor,

   162                         attributes2);

   163             translations.put(field, field2);

   164         }

   165         return field2;

   166     }

   167 

   168     Method[] translateMethods(Method[] methods, ConstantPool constant_pool, Map<Object,Object> translations) {

   169         Method[] methods2 = (Method[]) translations.get(methods);

   170         if (methods2 == null) {

   171             methods2 = new Method[methods.length];

   172             for (int i = 0; i < methods.length; i++)

   173                 methods2[i] = translate(methods[i], constant_pool, translations);

   174             if (equal(methods, methods2))

   175                 methods2 = methods;

   176             translations.put(methods, methods2);

   177         }

   178         return methods2;

   179     }

   180 

   181     Method translate(Method method, ConstantPool constant_pool, Map<Object,Object> translations) {

   182         Method method2 = (Method) translations.get(method);

   183         if (method2 == null) {

   184             Attributes attributes2 = translateAttributes(method.attributes, constant_pool,

   185                     translations);

   186 

   187             if (attributes2 == method.attributes)

   188                 method2 = method;

   189             else

   190                 method2 = new Method(

   191                         method.access_flags,

   192                         method.name_index,

   193                         method.descriptor,

   194                         attributes2);

   195             translations.put(method, method2);

   196         }

   197         return method2;

   198     }

   199 

   200     Attributes translateAttributes(Attributes attributes,

   201             ConstantPool constant_pool, Map<Object,Object> translations) {

   202         Attributes attributes2 = (Attributes) translations.get(attributes);

   203         if (attributes2 == null) {

   204             Attribute[] attrArray2 = new Attribute[attributes.size()];

   205             ConstantPool constant_pool2 = translate(constant_pool, translations);

   206             boolean attrsEqual = true;

   207             for (int i = 0; i < attributes.size(); i++) {

   208                 Attribute attr = attributes.get(i);

   209                 Attribute attr2 = translate(attr, translations);

   210                 if (attr2 != attr)

   211                     attrsEqual = false;

   212                 attrArray2[i] = attr2;

   213             }

   214             if ((constant_pool2 == constant_pool) && attrsEqual)

   215                 attributes2 = attributes;

   216             else

   217                 attributes2 = new Attributes(constant_pool2, attrArray2);

   218             translations.put(attributes, attributes2);

   219         }

   220         return attributes2;

   221     }

   222 

   223     Attribute translate(Attribute attribute, Map<Object,Object> translations) {

   224         Attribute attribute2 = (Attribute) translations.get(attribute);

   225         if (attribute2 == null) {

   226             attribute2 = attribute; // don't support translation within attributes yet

   227                                     // (what about Code attribute)

   228             translations.put(attribute, attribute2);

   229         }

   230         return attribute2;

   231     }

   232 

   233     private static <T> boolean equal(T[] a1, T[] a2) {

   234         if (a1 == null || a2 == null)

   235             return (a1 == a2);

   236         if (a1.length != a2.length)

   237             return false;

   238         for (int i = 0; i < a1.length; i++) {

   239             if (a1[i] != a2[i])

   240                 return false;

   241         }

   242         return true;

   243     }

   244 

   245     public CPInfo visitClass(CONSTANT_Class_info info, Map<Object, Object> translations) {

   246         CONSTANT_Class_info info2 = (CONSTANT_Class_info) translations.get(info);

   247         if (info2 == null) {

   248             ConstantPool cp2 = translate(info.cp, translations);

   249             if (cp2 == info.cp)

   250                 info2 = info;

   251             else

   252                 info2 = new CONSTANT_Class_info(cp2, info.name_index);

   253             translations.put(info, info2);

   254         }

   255         return info;

   256     }

   257 

   258     public CPInfo visitDouble(CONSTANT_Double_info info, Map<Object, Object> translations) {

   259         CONSTANT_Double_info info2 = (CONSTANT_Double_info) translations.get(info);

   260         if (info2 == null) {

   261             info2 = info;

   262             translations.put(info, info2);

   263         }

   264         return info;

   265     }

   266 

   267     public CPInfo visitFieldref(CONSTANT_Fieldref_info info, Map<Object, Object> translations) {

   268         CONSTANT_Fieldref_info info2 = (CONSTANT_Fieldref_info) translations.get(info);

   269         if (info2 == null) {

   270             ConstantPool cp2 = translate(info.cp, translations);

   271             if (cp2 == info.cp)

   272                 info2 = info;

   273             else

   274                 info2 = new CONSTANT_Fieldref_info(cp2, info.class_index, info.name_and_type_index);

   275             translations.put(info, info2);

   276         }

   277         return info;

   278     }

   279 

   280     public CPInfo visitFloat(CONSTANT_Float_info info, Map<Object, Object> translations) {

   281         CONSTANT_Float_info info2 = (CONSTANT_Float_info) translations.get(info);

   282         if (info2 == null) {

   283             info2 = info;

   284             translations.put(info, info2);

   285         }

   286         return info;

   287     }

   288 

   289     public CPInfo visitInteger(CONSTANT_Integer_info info, Map<Object, Object> translations) {

   290         CONSTANT_Integer_info info2 = (CONSTANT_Integer_info) translations.get(info);

   291         if (info2 == null) {

   292             info2 = info;

   293             translations.put(info, info2);

   294         }

   295         return info;

   296     }

   297 

   298     public CPInfo visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, Map<Object, Object> translations) {

   299         CONSTANT_InterfaceMethodref_info info2 = (CONSTANT_InterfaceMethodref_info) translations.get(info);

   300         if (info2 == null) {

   301             ConstantPool cp2 = translate(info.cp, translations);

   302             if (cp2 == info.cp)

   303                 info2 = info;

   304             else

   305                 info2 = new CONSTANT_InterfaceMethodref_info(cp2, info.class_index, info.name_and_type_index);

   306             translations.put(info, info2);

   307         }

   308         return info;

   309     }

   310 

   311     public CPInfo visitInvokeDynamic(CONSTANT_InvokeDynamic_info info, Map<Object, Object> translations) {

   312         CONSTANT_InvokeDynamic_info info2 = (CONSTANT_InvokeDynamic_info) translations.get(info);

   313         if (info2 == null) {

   314             ConstantPool cp2 = translate(info.cp, translations);

   315             if (cp2 == info.cp) {

   316                 info2 = info;

   317             } else {

   318                 info2 = new CONSTANT_InvokeDynamic_info(cp2, info.bootstrap_method_attr_index, info.name_and_type_index);

   319             }

   320             translations.put(info, info2);

   321         }

   322         return info;

   323     }

   324 

   325     public CPInfo visitLong(CONSTANT_Long_info info, Map<Object, Object> translations) {

   326         CONSTANT_Long_info info2 = (CONSTANT_Long_info) translations.get(info);

   327         if (info2 == null) {

   328             info2 = info;

   329             translations.put(info, info2);

   330         }

   331         return info;

   332     }

   333 

   334     public CPInfo visitNameAndType(CONSTANT_NameAndType_info info, Map<Object, Object> translations) {

   335         CONSTANT_NameAndType_info info2 = (CONSTANT_NameAndType_info) translations.get(info);

   336         if (info2 == null) {

   337             ConstantPool cp2 = translate(info.cp, translations);

   338             if (cp2 == info.cp)

   339                 info2 = info;

   340             else

   341                 info2 = new CONSTANT_NameAndType_info(cp2, info.name_index, info.type_index);

   342             translations.put(info, info2);

   343         }

   344         return info;

   345     }

   346 

   347     public CPInfo visitMethodref(CONSTANT_Methodref_info info, Map<Object, Object> translations) {

   348         CONSTANT_Methodref_info info2 = (CONSTANT_Methodref_info) translations.get(info);

   349         if (info2 == null) {

   350             ConstantPool cp2 = translate(info.cp, translations);

   351             if (cp2 == info.cp)

   352                 info2 = info;

   353             else

   354                 info2 = new CONSTANT_Methodref_info(cp2, info.class_index, info.name_and_type_index);

   355             translations.put(info, info2);

   356         }

   357         return info;

   358     }

   359 

   360     public CPInfo visitMethodHandle(CONSTANT_MethodHandle_info info, Map<Object, Object> translations) {

   361         CONSTANT_MethodHandle_info info2 = (CONSTANT_MethodHandle_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_MethodHandle_info(cp2, info.reference_kind, info.reference_index);

   368             }

   369             translations.put(info, info2);

   370         }

   371         return info;

   372     }

   373 

   374     public CPInfo visitMethodType(CONSTANT_MethodType_info info, Map<Object, Object> translations) {

   375         CONSTANT_MethodType_info info2 = (CONSTANT_MethodType_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_MethodType_info(cp2, info.descriptor_index);

   382             }

   383             translations.put(info, info2);

   384         }

   385         return info;

   386     }

   387 

   388     public CPInfo visitString(CONSTANT_String_info info, Map<Object, Object> translations) {

   389         CONSTANT_String_info info2 = (CONSTANT_String_info) translations.get(info);

   390         if (info2 == null) {

   391             ConstantPool cp2 = translate(info.cp, translations);

   392             if (cp2 == info.cp)

   393                 info2 = info;

   394             else

   395                 info2 = new CONSTANT_String_info(cp2, info.string_index);

   396             translations.put(info, info2);

   397         }

   398         return info;

   399     }

   400 

   401     public CPInfo visitUtf8(CONSTANT_Utf8_info info, Map<Object, Object> translations) {

   402         CONSTANT_Utf8_info info2 = (CONSTANT_Utf8_info) translations.get(info);

   403         if (info2 == null) {

   404             info2 = info;

   405             translations.put(info, info2);

   406         }

   407         return info;

   408     }

   409 

   410 }