1 /*

     2  * Copyright (c) 2008, 2009, 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 sun.dyn.anon;

    27 

    28 import java.io.IOException;

    29 import java.io.OutputStream;

    30 import java.util.Arrays;

    31 import java.util.HashSet;

    32 import java.util.IdentityHashMap;

    33 import java.util.Map;

    34 

    35 import static sun.dyn.anon.ConstantPoolVisitor.*;

    36 

    37 /** A class and its patched constant pool.

    38  *

    39  *  This class allow to modify (patch) a constant pool

    40  *  by changing the value of its entry.

    41  *  Entry are referenced using index that can be get

    42  *  by parsing the constant pool using

    43  *  {@link ConstantPoolParser#parse(ConstantPoolVisitor)}.

    44  *

    45  * @see ConstantPoolVisitor

    46  * @see ConstantPoolParser#createPatch()

    47  */

    48 public class ConstantPoolPatch {

    49     final ConstantPoolParser outer;

    50     final Object[] patchArray;

    51 

    52     ConstantPoolPatch(ConstantPoolParser outer) {

    53         this.outer      = outer;

    54         this.patchArray = new Object[outer.getLength()];

    55     }

    56 

    57     /** Create a {@link ConstantPoolParser} and

    58      *  a {@link ConstantPoolPatch} in one step.

    59      *  Equivalent to {@code new ConstantPoolParser(classFile).createPatch()}.

    60      *

    61      * @param classFile an array of bytes containing a class.

    62      * @see #ConstantPoolParser(Class)

    63      */

    64     public ConstantPoolPatch(byte[] classFile) throws InvalidConstantPoolFormatException {

    65         this(new ConstantPoolParser(classFile));

    66     }

    67 

    68     /** Create a {@link ConstantPoolParser} and

    69      *  a {@link ConstantPoolPatch} in one step.

    70      *  Equivalent to {@code new ConstantPoolParser(templateClass).createPatch()}.

    71      *

    72      * @param templateClass the class to parse.

    73      * @see #ConstantPoolParser(Class)

    74      */

    75     public ConstantPoolPatch(Class<?> templateClass) throws IOException, InvalidConstantPoolFormatException {

    76         this(new ConstantPoolParser(templateClass));

    77     }

    78 

    79 

    80     /** Creates a patch from an existing patch.

    81      *  All changes are copied from that patch.

    82      * @param patch a patch

    83      *

    84      * @see ConstantPoolParser#createPatch()

    85      */

    86     public ConstantPoolPatch(ConstantPoolPatch patch) {

    87         outer      = patch.outer;

    88         patchArray = patch.patchArray.clone();

    89     }

    90 

    91     /** Which parser built this patch? */

    92     public ConstantPoolParser getParser() {

    93         return outer;

    94     }

    95 

    96     /** Report the tag at the given index in the constant pool. */

    97     public byte getTag(int index) {

    98         return outer.getTag(index);

    99     }

   100 

   101     /** Report the current patch at the given index of the constant pool.

   102      *  Null means no patch will be made.

   103      *  To observe the unpatched entry at the given index, use

   104      *  {@link #getParser()}{@code .}@link ConstantPoolParser#parse(ConstantPoolVisitor)}

   105      */

   106     public Object getPatch(int index) {

   107         Object value = patchArray[index];

   108         if (value == null)  return null;

   109         switch (getTag(index)) {

   110         case CONSTANT_Fieldref:

   111         case CONSTANT_Methodref:

   112         case CONSTANT_InterfaceMethodref:

   113             if (value instanceof String)

   114                 value = stripSemis(2, (String) value);

   115             break;

   116         case CONSTANT_NameAndType:

   117             if (value instanceof String)

   118                 value = stripSemis(1, (String) value);

   119             break;

   120         }

   121         return value;

   122     }

   123 

   124     /** Clear all patches. */

   125     public void clear() {

   126         Arrays.fill(patchArray, null);

   127     }

   128 

   129     /** Clear one patch. */

   130     public void clear(int index) {

   131         patchArray[index] = null;

   132     }

   133 

   134     /** Produce the patches as an array. */

   135     public Object[] getPatches() {

   136         return patchArray.clone();

   137     }

   138 

   139     /** Produce the original constant pool as an array. */

   140     public Object[] getOriginalCP() throws InvalidConstantPoolFormatException {

   141         return getOriginalCP(0, patchArray.length, -1);

   142     }

   143 

   144     /** Walk the constant pool, applying patches using the given map.

   145      *

   146      * @param utf8Map Utf8 strings to modify, if encountered

   147      * @param classMap Classes (or their names) to modify, if encountered

   148      * @param valueMap Constant values to modify, if encountered

   149      * @param deleteUsedEntries if true, delete map entries that are used

   150      */

   151     public void putPatches(final Map<String,String> utf8Map,

   152                            final Map<String,Object> classMap,

   153                            final Map<Object,Object> valueMap,

   154                            boolean deleteUsedEntries) throws InvalidConstantPoolFormatException {

   155         final HashSet<String> usedUtf8Keys;

   156         final HashSet<String> usedClassKeys;

   157         final HashSet<Object> usedValueKeys;

   158         if (deleteUsedEntries) {

   159             usedUtf8Keys  = (utf8Map  == null) ? null : new HashSet<String>();

   160             usedClassKeys = (classMap == null) ? null : new HashSet<String>();

   161             usedValueKeys = (valueMap == null) ? null : new HashSet<Object>();

   162         } else {

   163             usedUtf8Keys = null;

   164             usedClassKeys = null;

   165             usedValueKeys = null;

   166         }

   167 

   168         outer.parse(new ConstantPoolVisitor() {

   169 

   170             @Override

   171             public void visitUTF8(int index, byte tag, String utf8) {

   172                 putUTF8(index, utf8Map.get(utf8));

   173                 if (usedUtf8Keys != null)  usedUtf8Keys.add(utf8);

   174             }

   175 

   176             @Override

   177             public void visitConstantValue(int index, byte tag, Object value) {

   178                 putConstantValue(index, tag, valueMap.get(value));

   179                 if (usedValueKeys != null)  usedValueKeys.add(value);

   180             }

   181 

   182             @Override

   183             public void visitConstantString(int index, byte tag, String name, int nameIndex) {

   184                 if (tag == CONSTANT_Class) {

   185                     putConstantValue(index, tag, classMap.get(name));

   186                     if (usedClassKeys != null)  usedClassKeys.add(name);

   187                 } else {

   188                     assert(tag == CONSTANT_String);

   189                     visitConstantValue(index, tag, name);

   190                 }

   191             }

   192         });

   193         if (usedUtf8Keys != null)   utf8Map.keySet().removeAll(usedUtf8Keys);

   194         if (usedClassKeys != null)  classMap.keySet().removeAll(usedClassKeys);

   195         if (usedValueKeys != null)  valueMap.keySet().removeAll(usedValueKeys);

   196     }

   197 

   198     Object[] getOriginalCP(final int startIndex,

   199                            final int endIndex,

   200                            final int tagMask) throws InvalidConstantPoolFormatException {

   201         final Object[] cpArray = new Object[endIndex - startIndex];

   202         outer.parse(new ConstantPoolVisitor() {

   203 

   204             void show(int index, byte tag, Object value) {

   205                 if (index < startIndex || index >= endIndex)  return;

   206                 if (((1 << tag) & tagMask) == 0)  return;

   207                 cpArray[index - startIndex] = value;

   208             }

   209 

   210             @Override

   211             public void visitUTF8(int index, byte tag, String utf8) {

   212                 show(index, tag, utf8);

   213             }

   214 

   215             @Override

   216             public void visitConstantValue(int index, byte tag, Object value) {

   217                 assert(tag != CONSTANT_String);

   218                 show(index, tag, value);

   219             }

   220 

   221             @Override

   222             public void visitConstantString(int index, byte tag,

   223                                             String value, int j) {

   224                 show(index, tag, value);

   225             }

   226 

   227             @Override

   228             public void visitMemberRef(int index, byte tag,

   229                     String className, String memberName,

   230                     String signature,

   231                     int j, int k) {

   232                 show(index, tag, new String[]{ className, memberName, signature });

   233             }

   234 

   235             @Override

   236             public void visitDescriptor(int index, byte tag,

   237                     String memberName, String signature,

   238                     int j, int k) {

   239                 show(index, tag, new String[]{ memberName, signature });

   240             }

   241         });

   242         return cpArray;

   243     }

   244 

   245     /** Write the head (header plus constant pool)

   246      *  of the patched class file to the indicated stream.

   247      */

   248     void writeHead(OutputStream out) throws IOException {

   249         outer.writePatchedHead(out, patchArray);

   250     }

   251 

   252     /** Write the tail (everything after the constant pool)

   253      *  of the patched class file to the indicated stream.

   254      */

   255     void writeTail(OutputStream out) throws IOException {

   256         outer.writeTail(out);

   257     }

   258 

   259     private void checkConstantTag(byte tag, Object value) {

   260         if (value == null)

   261             throw new IllegalArgumentException(

   262                     "invalid null constant value");

   263         if (classForTag(tag) != value.getClass())

   264             throw new IllegalArgumentException(

   265                     "invalid constant value"

   266                     + (tag == CONSTANT_None ? ""

   267                         : " for tag "+tagName(tag))

   268                     + " of class "+value.getClass());

   269     }

   270 

   271     private void checkTag(int index, byte putTag) {

   272         byte tag = outer.tags[index];

   273         if (tag != putTag)

   274             throw new IllegalArgumentException(

   275                 "invalid put operation"

   276                 + " for " + tagName(putTag)

   277                 + " at index " + index + " found " + tagName(tag));

   278     }

   279 

   280     private void checkTagMask(int index, int tagBitMask) {

   281         byte tag = outer.tags[index];

   282         int tagBit = ((tag & 0x1F) == tag) ? (1 << tag) : 0;

   283         if ((tagBit & tagBitMask) == 0)

   284             throw new IllegalArgumentException(

   285                 "invalid put operation"

   286                 + " at index " + index + " found " + tagName(tag));

   287     }

   288 

   289     private static void checkMemberName(String memberName) {

   290         if (memberName.indexOf(';') >= 0)

   291             throw new IllegalArgumentException("memberName " + memberName + " contains a ';'");

   292     }

   293 

   294     /** Set the entry of the constant pool indexed by index to

   295      *  a new string.

   296      *

   297      * @param index an index to a constant pool entry containing a

   298      *        {@link ConstantPoolVisitor#CONSTANT_Utf8} value.

   299      * @param utf8 a string

   300      *

   301      * @see ConstantPoolVisitor#visitUTF8(int, byte, String)

   302      */

   303     public void putUTF8(int index, String utf8) {

   304         if (utf8 == null) { clear(index); return; }

   305         checkTag(index, CONSTANT_Utf8);

   306         patchArray[index] = utf8;

   307     }

   308 

   309     /** Set the entry of the constant pool indexed by index to

   310      *  a new value, depending on its dynamic type.

   311      *

   312      * @param index an index to a constant pool entry containing a

   313      *        one of the following structures:

   314      *        {@link ConstantPoolVisitor#CONSTANT_Integer},

   315      *        {@link ConstantPoolVisitor#CONSTANT_Float},

   316      *        {@link ConstantPoolVisitor#CONSTANT_Long},

   317      *        {@link ConstantPoolVisitor#CONSTANT_Double},

   318      *        {@link ConstantPoolVisitor#CONSTANT_String}, or

   319      *        {@link ConstantPoolVisitor#CONSTANT_Class}

   320      * @param value a boxed int, float, long or double; or a string or class object

   321      * @throws IllegalArgumentException if the type of the constant does not

   322      *         match the constant pool entry type,

   323      *         as reported by {@link #getTag(int)}

   324      *

   325      * @see #putConstantValue(int, byte, Object)

   326      * @see ConstantPoolVisitor#visitConstantValue(int, byte, Object)

   327      * @see ConstantPoolVisitor#visitConstantString(int, byte, String, int)

   328      */

   329     public void putConstantValue(int index, Object value) {

   330         if (value == null) { clear(index); return; }

   331         byte tag = tagForConstant(value.getClass());

   332         checkConstantTag(tag, value);

   333         checkTag(index, tag);

   334         patchArray[index] = value;

   335     }

   336 

   337     /** Set the entry of the constant pool indexed by index to

   338      *  a new value.

   339      *

   340      * @param index an index to a constant pool entry matching the given tag

   341      * @param tag one of the following values:

   342      *        {@link ConstantPoolVisitor#CONSTANT_Integer},

   343      *        {@link ConstantPoolVisitor#CONSTANT_Float},

   344      *        {@link ConstantPoolVisitor#CONSTANT_Long},

   345      *        {@link ConstantPoolVisitor#CONSTANT_Double},

   346      *        {@link ConstantPoolVisitor#CONSTANT_String}, or

   347      *        {@link ConstantPoolVisitor#CONSTANT_Class}

   348      * @param value a boxed number, string, or class object

   349      * @throws IllegalArgumentException if the type of the constant does not

   350      *         match the constant pool entry type, or if a class name contains

   351      *         '/' or ';'

   352      *

   353      * @see #putConstantValue(int, Object)

   354      * @see ConstantPoolVisitor#visitConstantValue(int, byte, Object)

   355      * @see ConstantPoolVisitor#visitConstantString(int, byte, String, int)

   356      */

   357     public void putConstantValue(int index, byte tag, Object value) {

   358         if (value == null) { clear(index); return; }

   359         checkTag(index, tag);

   360         if (tag == CONSTANT_Class && value instanceof String) {

   361             checkClassName((String) value);

   362         } else if (tag == CONSTANT_String) {

   363             // the JVM accepts any object as a patch for a string

   364         } else {

   365             // make sure the incoming value is the right type

   366             checkConstantTag(tag, value);

   367         }

   368         checkTag(index, tag);

   369         patchArray[index] = value;

   370     }

   371 

   372     /** Set the entry of the constant pool indexed by index to

   373      *  a new {@link ConstantPoolVisitor#CONSTANT_NameAndType} value.

   374      *

   375      * @param index an index to a constant pool entry containing a

   376      *        {@link ConstantPoolVisitor#CONSTANT_NameAndType} value.

   377      * @param memberName a memberName

   378      * @param signature a signature

   379      * @throws IllegalArgumentException if memberName contains the character ';'

   380      *

   381      * @see ConstantPoolVisitor#visitDescriptor(int, byte, String, String, int, int)

   382      */

   383     public void putDescriptor(int index, String memberName, String signature) {

   384         checkTag(index, CONSTANT_NameAndType);

   385         checkMemberName(memberName);

   386         patchArray[index] = addSemis(memberName, signature);

   387     }

   388 

   389     /** Set the entry of the constant pool indexed by index to

   390      *  a new {@link ConstantPoolVisitor#CONSTANT_Fieldref},

   391      *  {@link ConstantPoolVisitor#CONSTANT_Methodref}, or

   392      *  {@link ConstantPoolVisitor#CONSTANT_InterfaceMethodref} value.

   393      *

   394      * @param index an index to a constant pool entry containing a member reference

   395      * @param className a class name

   396      * @param memberName a field or method name

   397      * @param signature a field or method signature

   398      * @throws IllegalArgumentException if memberName contains the character ';'

   399      *             or signature is not a correct signature

   400      *

   401      * @see ConstantPoolVisitor#visitMemberRef(int, byte, String, String, String, int, int)

   402      */

   403     public void putMemberRef(int index, byte tag,

   404                     String className, String memberName, String signature) {

   405         checkTagMask(tag, CONSTANT_MemberRef_MASK);

   406         checkTag(index, tag);

   407         checkClassName(className);

   408         checkMemberName(memberName);

   409         if (signature.startsWith("(") == (tag == CONSTANT_Fieldref))

   410             throw new IllegalArgumentException("bad signature: "+signature);

   411         patchArray[index] = addSemis(className, memberName, signature);

   412     }

   413 

   414     static private final int CONSTANT_MemberRef_MASK =

   415               CONSTANT_Fieldref

   416             | CONSTANT_Methodref

   417             | CONSTANT_InterfaceMethodref;

   418 

   419     private static final Map<Class<?>, Byte> CONSTANT_VALUE_CLASS_TAG

   420         = new IdentityHashMap<Class<?>, Byte>();

   421     private static final Class[] CONSTANT_VALUE_CLASS = new Class[16];

   422     static {

   423         Object[][] values = {

   424             {Integer.class, CONSTANT_Integer},

   425             {Long.class, CONSTANT_Long},

   426             {Float.class, CONSTANT_Float},

   427             {Double.class, CONSTANT_Double},

   428             {String.class, CONSTANT_String},

   429             {Class.class, CONSTANT_Class}

   430         };

   431         for (Object[] value : values) {

   432             Class<?> cls = (Class<?>)value[0];

   433             Byte     tag = (Byte) value[1];

   434             CONSTANT_VALUE_CLASS_TAG.put(cls, tag);

   435             CONSTANT_VALUE_CLASS[(byte)tag] = cls;

   436         }

   437     }

   438 

   439     static Class<?> classForTag(byte tag) {

   440         if ((tag & 0xFF) >= CONSTANT_VALUE_CLASS.length)

   441             return null;

   442         return CONSTANT_VALUE_CLASS[tag];

   443     }

   444 

   445     static byte tagForConstant(Class<?> cls) {

   446         Byte tag = CONSTANT_VALUE_CLASS_TAG.get(cls);

   447         return (tag == null) ? CONSTANT_None : (byte)tag;

   448     }

   449 

   450     private static void checkClassName(String className) {

   451         if (className.indexOf('/') >= 0 || className.indexOf(';') >= 0)

   452             throw new IllegalArgumentException("invalid class name " + className);

   453     }

   454 

   455     static String addSemis(String name, String... names) {

   456         StringBuilder buf = new StringBuilder(name.length() * 5);

   457         buf.append(name);

   458         for (String name2 : names) {

   459             buf.append(';').append(name2);

   460         }

   461         String res = buf.toString();

   462         assert(stripSemis(names.length, res)[0].equals(name));

   463         assert(stripSemis(names.length, res)[1].equals(names[0]));

   464         assert(names.length == 1 ||

   465                stripSemis(names.length, res)[2].equals(names[1]));

   466         return res;

   467     }

   468 

   469     static String[] stripSemis(int count, String string) {

   470         String[] res = new String[count+1];

   471         int pos = 0;

   472         for (int i = 0; i < count; i++) {

   473             int pos2 = string.indexOf(';', pos);

   474             if (pos2 < 0)  pos2 = string.length();  // yuck

   475             res[i] = string.substring(pos, pos2);

   476             pos = pos2;

   477         }

   478         res[count] = string.substring(pos);

   479         return res;

   480     }

   481 

   482     public String toString() {

   483         StringBuilder buf = new StringBuilder(this.getClass().getName());

   484         buf.append("{");

   485         Object[] origCP = null;

   486         for (int i = 0; i < patchArray.length; i++) {

   487             if (patchArray[i] == null)  continue;

   488             if (origCP != null) {

   489                 buf.append(", ");

   490             } else {

   491                 try {

   492                     origCP = getOriginalCP();

   493                 } catch (InvalidConstantPoolFormatException ee) {

   494                     origCP = new Object[0];

   495                 }

   496             }

   497             Object orig = (i < origCP.length) ? origCP[i] : "?";

   498             buf.append(orig).append("=").append(patchArray[i]);

   499         }

   500         buf.append("}");

   501         return buf.toString();

   502     }

   503 }