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    1   /*
    2    * Copyright  2000-2004 The Apache Software Foundation
    3    *
    4    *  Licensed under the Apache License, Version 2.0 (the "License");
    5    *  you may not use this file except in compliance with the License.
    6    *  You may obtain a copy of the License at
    7    *
    8    *      http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   *  Unless required by applicable law or agreed to in writing, software
    11   *  distributed under the License is distributed on an "AS IS" BASIS,
    12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   *  See the License for the specific language governing permissions and
    14   *  limitations under the License.
    15   *
    16   */
    17  package org.apache.bcel.util;
    18
    19  import java.io.FileOutputStream;
    20  import java.io.IOException;
    21  import java.io.PrintWriter;
    22  import java.util.BitSet;
    23  import org.apache.bcel.classfile.Attribute;
    24  import org.apache.bcel.classfile.Code;
    25  import org.apache.bcel.classfile.CodeException;
    26  import org.apache.bcel.classfile.ConstantFieldref;
    27  import org.apache.bcel.classfile.ConstantInterfaceMethodref;
    28  import org.apache.bcel.classfile.ConstantMethodref;
    29  import org.apache.bcel.classfile.ConstantNameAndType;
    30  import org.apache.bcel.classfile.ConstantPool;
    31  import org.apache.bcel.classfile.LocalVariable;
    32  import org.apache.bcel.classfile.LocalVariableTable;
    33  import org.apache.bcel.classfile.Method;
    34  import org.apache.bcel.classfile.Utility;
    35
    36  /***
    37   * Convert code into HTML file.
    38   *
    39   * @version $Id: CodeHTML.java 386056 2006-03-15 11:31:56Z tcurdt $
    40   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
    41   *
    42   */
    43  final class CodeHTML implements org.apache.bcel.Constants {
    44
    45      private String class_name; // name of current class
    46      private Method[] methods; // Methods to print
    47      private PrintWriter file; // file to write to
    48      private BitSet goto_set;
    49      private ConstantPool constant_pool;
    50      private ConstantHTML constant_html;
    51      private static boolean wide = false;
    52
    53
    54      CodeHTML(String dir, String class_name, Method[] methods, ConstantPool constant_pool,
    55              ConstantHTML constant_html) throws IOException {
    56          this.class_name = class_name;
    57          this.methods = methods;
    58          this.constant_pool = constant_pool;
    59          this.constant_html = constant_html;
    60          file = new PrintWriter(new FileOutputStream(dir + class_name + "_code.html"));
    61          file.println("<HTML><BODY BGCOLOR=\"#C0C0C0\">");
    62          for (int i = 0; i < methods.length; i++) {
    63              writeMethod(methods[i], i);
    64          }
    65          file.println("</BODY></HTML>");
    66          file.close();
    67      }
    68
    69
    70      /***
    71       * Disassemble a stream of byte codes and return the
    72       * string representation.
    73       *
    74       * @param  stream data input stream
    75       * @return String representation of byte code
    76       */
    77      private final String codeToHTML( ByteSequence bytes, int method_number ) throws IOException {
    78          short opcode = (short) bytes.readUnsignedByte();
    79          StringBuffer buf;
    80          String name, signature;
    81          int default_offset = 0, low, high;
    82          int index, class_index, vindex, constant;
    83          int[] jump_table;
    84          int no_pad_bytes = 0, offset;
    85          buf = new StringBuffer(256);
    86          buf.append("<TT>").append(OPCODE_NAMES[opcode]).append("</TT></TD><TD>");
    87          /* Special case: Skip (0-3) padding bytes, i.e., the
    88           * following bytes are 4-byte-aligned
    89           */
    90          if ((opcode == TABLESWITCH) || (opcode == LOOKUPSWITCH)) {
    91              int remainder = bytes.getIndex() % 4;
    92              no_pad_bytes = (remainder == 0) ? 0 : 4 - remainder;
    93              for (int i = 0; i < no_pad_bytes; i++) {
    94                  bytes.readByte();
    95              }
    96              // Both cases have a field default_offset in common
    97              default_offset = bytes.readInt();
    98          }
    99          switch (opcode) {
    100             case TABLESWITCH:
    101                 low = bytes.readInt();
    102                 high = bytes.readInt();
    103                 offset = bytes.getIndex() - 12 - no_pad_bytes - 1;
    104                 default_offset += offset;
    105                 buf.append("<TABLE BORDER=1><TR>");
    106                 // Print switch indices in first row (and default)
    107                 jump_table = new int[high - low + 1];
    108                 for (int i = 0; i < jump_table.length; i++) {
    109                     jump_table[i] = offset + bytes.readInt();
    110                     buf.append("<TH>").append(low + i).append("</TH>");
    111                 }
    112                 buf.append("<TH>default</TH></TR>\n<TR>");
    113                 // Print target and default indices in second row
    114                 for (int i = 0; i < jump_table.length; i++) {
    115                     buf.append("<TD><A HREF=\"#code").append(method_number).append("@").append(
    116                             jump_table[i]).append("\">").append(jump_table[i]).append("</A></TD>");
    117                 }
    118                 buf.append("<TD><A HREF=\"#code").append(method_number).append("@").append(
    119                         default_offset).append("\">").append(default_offset).append(
    120                         "</A></TD></TR>\n</TABLE>\n");
    121                 break;
    122             /* Lookup switch has variable length arguments.
    123              */
    124             case LOOKUPSWITCH:
    125                 int npairs = bytes.readInt();
    126                 offset = bytes.getIndex() - 8 - no_pad_bytes - 1;
    127                 jump_table = new int[npairs];
    128                 default_offset += offset;
    129                 buf.append("<TABLE BORDER=1><TR>");
    130                 // Print switch indices in first row (and default)
    131                 for (int i = 0; i < npairs; i++) {
    132                     int match = bytes.readInt();
    133                     jump_table[i] = offset + bytes.readInt();
    134                     buf.append("<TH>").append(match).append("</TH>");
    135                 }
    136                 buf.append("<TH>default</TH></TR>\n<TR>");
    137                 // Print target and default indices in second row
    138                 for (int i = 0; i < npairs; i++) {
    139                     buf.append("<TD><A HREF=\"#code").append(method_number).append("@").append(
    140                             jump_table[i]).append("\">").append(jump_table[i]).append("</A></TD>");
    141                 }
    142                 buf.append("<TD><A HREF=\"#code").append(method_number).append("@").append(
    143                         default_offset).append("\">").append(default_offset).append(
    144                         "</A></TD></TR>\n</TABLE>\n");
    145                 break;
    146             /* Two address bytes + offset from start of byte stream form the
    147              * jump target.
    148              */
    149             case GOTO:
    150             case IFEQ:
    151             case IFGE:
    152             case IFGT:
    153             case IFLE:
    154             case IFLT:
    155             case IFNE:
    156             case IFNONNULL:
    157             case IFNULL:
    158             case IF_ACMPEQ:
    159             case IF_ACMPNE:
    160             case IF_ICMPEQ:
    161             case IF_ICMPGE:
    162             case IF_ICMPGT:
    163             case IF_ICMPLE:
    164             case IF_ICMPLT:
    165             case IF_ICMPNE:
    166             case JSR:
    167                 index = (int) (bytes.getIndex() + bytes.readShort() - 1);
    168                 buf.append("<A HREF=\"#code").append(method_number).append("@").append(index)
    169                         .append("\">").append(index).append("</A>");
    170                 break;
    171             /* Same for 32-bit wide jumps
    172              */
    173             case GOTO_W:
    174             case JSR_W:
    175                 int windex = bytes.getIndex() + bytes.readInt() - 1;
    176                 buf.append("<A HREF=\"#code").append(method_number).append("@").append(windex)
    177                         .append("\">").append(windex).append("</A>");
    178                 break;
    179             /* Index byte references local variable (register)
    180              */
    181             case ALOAD:
    182             case ASTORE:
    183             case DLOAD:
    184             case DSTORE:
    185             case FLOAD:
    186             case FSTORE:
    187             case ILOAD:
    188             case ISTORE:
    189             case LLOAD:
    190             case LSTORE:
    191             case RET:
    192                 if (wide) {
    193                     vindex = bytes.readShort();
    194                     wide = false; // Clear flag
    195                 } else {
    196                     vindex = bytes.readUnsignedByte();
    197                 }
    198                 buf.append("%").append(vindex);
    199                 break;
    200             /*
    201              * Remember wide byte which is used to form a 16-bit address in the
    202              * following instruction. Relies on that the method is called again with
    203              * the following opcode.
    204              */
    205             case WIDE:
    206                 wide = true;
    207                 buf.append("(wide)");
    208                 break;
    209             /* Array of basic type.
    210              */
    211             case NEWARRAY:
    212                 buf.append("<FONT COLOR=\"#00FF00\">").append(TYPE_NAMES[bytes.readByte()]).append(
    213                         "</FONT>");
    214                 break;
    215             /* Access object/class fields.
    216              */
    217             case GETFIELD:
    218             case GETSTATIC:
    219             case PUTFIELD:
    220             case PUTSTATIC:
    221                 index = bytes.readShort();
    222                 ConstantFieldref c1 = (ConstantFieldref) constant_pool.getConstant(index,
    223                         CONSTANT_Fieldref);
    224                 class_index = c1.getClassIndex();
    225                 name = constant_pool.getConstantString(class_index, CONSTANT_Class);
    226                 name = Utility.compactClassName(name, false);
    227                 index = c1.getNameAndTypeIndex();
    228                 String field_name = constant_pool.constantToString(index, CONSTANT_NameAndType);
    229                 if (name.equals(class_name)) { // Local field
    230                     buf.append("<A HREF=\"").append(class_name).append("_methods.html#field")
    231                             .append(field_name).append("\" TARGET=Methods>").append(field_name)
    232                             .append("</A>\n");
    233                 } else {
    234                     buf.append(constant_html.referenceConstant(class_index)).append(".").append(
    235                             field_name);
    236                 }
    237                 break;
    238             /* Operands are references to classes in constant pool
    239              */
    240             case CHECKCAST:
    241             case INSTANCEOF:
    242             case NEW:
    243                 index = bytes.readShort();
    244                 buf.append(constant_html.referenceConstant(index));
    245                 break;
    246             /* Operands are references to methods in constant pool
    247              */
    248             case INVOKESPECIAL:
    249             case INVOKESTATIC:
    250             case INVOKEVIRTUAL:
    251             case INVOKEINTERFACE:
    252                 int m_index = bytes.readShort();
    253                 String str;
    254                 if (opcode == INVOKEINTERFACE) { // Special treatment needed
    255                     int nargs = bytes.readUnsignedByte(); // Redundant
    256                     int reserved = bytes.readUnsignedByte(); // Reserved
    257                     ConstantInterfaceMethodref c = (ConstantInterfaceMethodref) constant_pool
    258                             .getConstant(m_index, CONSTANT_InterfaceMethodref);
    259                     class_index = c.getClassIndex();
    260                     str = constant_pool.constantToString(c);
    261                     index = c.getNameAndTypeIndex();
    262                 } else {
    263                     ConstantMethodref c = (ConstantMethodref) constant_pool.getConstant(m_index,
    264                             CONSTANT_Methodref);
    265                     class_index = c.getClassIndex();
    266                     str = constant_pool.constantToString(c);
    267                     index = c.getNameAndTypeIndex();
    268                 }
    269                 name = Class2HTML.referenceClass(class_index);
    270                 str = Class2HTML.toHTML(constant_pool.constantToString(constant_pool.getConstant(
    271                         index, CONSTANT_NameAndType)));
    272                 // Get signature, i.e., types
    273                 ConstantNameAndType c2 = (ConstantNameAndType) constant_pool.getConstant(index,
    274                         CONSTANT_NameAndType);
    275                 signature = constant_pool.constantToString(c2.getSignatureIndex(), CONSTANT_Utf8);
    276                 String[] args = Utility.methodSignatureArgumentTypes(signature, false);
    277                 String type = Utility.methodSignatureReturnType(signature, false);
    278                 buf.append(name).append(".<A HREF=\"").append(class_name).append("_cp.html#cp")
    279                         .append(m_index).append("\" TARGET=ConstantPool>").append(str).append(
    280                                 "</A>").append("(");
    281                 // List arguments
    282                 for (int i = 0; i < args.length; i++) {
    283                     buf.append(Class2HTML.referenceType(args[i]));
    284                     if (i < args.length - 1) {
    285                         buf.append(", ");
    286                     }
    287                 }
    288                 // Attach return type
    289                 buf.append("):").append(Class2HTML.referenceType(type));
    290                 break;
    291             /* Operands are references to items in constant pool
    292              */
    293             case LDC_W:
    294             case LDC2_W:
    295                 index = bytes.readShort();
    296                 buf.append("<A HREF=\"").append(class_name).append("_cp.html#cp").append(index)
    297                         .append("\" TARGET=\"ConstantPool\">").append(
    298                                 Class2HTML.toHTML(constant_pool.constantToString(index,
    299                                         constant_pool.getConstant(index).getTag()))).append("</a>");
    300                 break;
    301             case LDC:
    302                 index = bytes.readUnsignedByte();
    303                 buf.append("<A HREF=\"").append(class_name).append("_cp.html#cp").append(index)
    304                         .append("\" TARGET=\"ConstantPool\">").append(
    305                                 Class2HTML.toHTML(constant_pool.constantToString(index,
    306                                         constant_pool.getConstant(index).getTag()))).append("</a>");
    307                 break;
    308             /* Array of references.
    309              */
    310             case ANEWARRAY:
    311                 index = bytes.readShort();
    312                 buf.append(constant_html.referenceConstant(index));
    313                 break;
    314             /* Multidimensional array of references.
    315              */
    316             case MULTIANEWARRAY:
    317                 index = bytes.readShort();
    318                 int dimensions = bytes.readByte();
    319                 buf.append(constant_html.referenceConstant(index)).append(":").append(dimensions)
    320                         .append("-dimensional");
    321                 break;
    322             /* Increment local variable.
    323              */
    324             case IINC:
    325                 if (wide) {
    326                     vindex = bytes.readShort();
    327                     constant = bytes.readShort();
    328                     wide = false;
    329                 } else {
    330                     vindex = bytes.readUnsignedByte();
    331                     constant = bytes.readByte();
    332                 }
    333                 buf.append("%").append(vindex).append(" ").append(constant);
    334                 break;
    335             default:
    336                 if (NO_OF_OPERANDS[opcode] > 0) {
    337                     for (int i = 0; i < TYPE_OF_OPERANDS[opcode].length; i++) {
    338                         switch (TYPE_OF_OPERANDS[opcode][i]) {
    339                             case T_BYTE:
    340                                 buf.append(bytes.readUnsignedByte());
    341                                 break;
    342                             case T_SHORT: // Either branch or index
    343                                 buf.append(bytes.readShort());
    344                                 break;
    345                             case T_INT:
    346                                 buf.append(bytes.readInt());
    347                                 break;
    348                             default: // Never reached
    349                                 System.err.println("Unreachable default case reached!");
    350                                 System.exit(-1);
    351                         }
    352                         buf.append("&nbsp;");
    353                     }
    354                 }
    355         }
    356         buf.append("</TD>");
    357         return buf.toString();
    358     }
    359
    360
    361     /***
    362      * Find all target addresses in code, so that they can be marked
    363      * with &lt;A NAME = ...&gt;. Target addresses are kept in an BitSet object.
    364      */
    365     private final void findGotos( ByteSequence bytes, Method method, Code code ) throws IOException {
    366         int index;
    367         goto_set = new BitSet(bytes.available());
    368         int opcode;
    369         /* First get Code attribute from method and the exceptions handled
    370          * (try .. catch) in this method. We only need the line number here.
    371          */
    372         if (code != null) {
    373             CodeException[] ce = code.getExceptionTable();
    374             int len = ce.length;
    375             for (int i = 0; i < len; i++) {
    376                 goto_set.set(ce[i].getStartPC());
    377                 goto_set.set(ce[i].getEndPC());
    378                 goto_set.set(ce[i].getHandlerPC());
    379             }
    380             // Look for local variables and their range
    381             Attribute[] attributes = code.getAttributes();
    382             for (int i = 0; i < attributes.length; i++) {
    383                 if (attributes[i].getTag() == ATTR_LOCAL_VARIABLE_TABLE) {
    384                     LocalVariable[] vars = ((LocalVariableTable) attributes[i])
    385                             .getLocalVariableTable();
    386                     for (int j = 0; j < vars.length; j++) {
    387                         int start = vars[j].getStartPC();
    388                         int end = (int) (start + vars[j].getLength());
    389                         goto_set.set(start);
    390                         goto_set.set(end);
    391                     }
    392                     break;
    393                 }
    394             }
    395         }
    396         // Get target addresses from GOTO, JSR, TABLESWITCH, etc.
    397         for (int i = 0; bytes.available() > 0; i++) {
    398             opcode = bytes.readUnsignedByte();
    399             //System.out.println(OPCODE_NAMES[opcode]);
    400             switch (opcode) {
    401                 case TABLESWITCH:
    402                 case LOOKUPSWITCH:
    403                     //bytes.readByte(); // Skip already read byte
    404                     int remainder = bytes.getIndex() % 4;
    405                     int no_pad_bytes = (remainder == 0) ? 0 : 4 - remainder;
    406                     int default_offset,
    407                     offset;
    408                     for (int j = 0; j < no_pad_bytes; j++) {
    409                         bytes.readByte();
    410                     }
    411                     // Both cases have a field default_offset in common
    412                     default_offset = bytes.readInt();
    413                     if (opcode == TABLESWITCH) {
    414                         int low = bytes.readInt();
    415                         int high = bytes.readInt();
    416                         offset = bytes.getIndex() - 12 - no_pad_bytes - 1;
    417                         default_offset += offset;
    418                         goto_set.set(default_offset);
    419                         for (int j = 0; j < (high - low + 1); j++) {
    420                             index = offset + bytes.readInt();
    421                             goto_set.set(index);
    422                         }
    423                     } else { // LOOKUPSWITCH
    424                         int npairs = bytes.readInt();
    425                         offset = bytes.getIndex() - 8 - no_pad_bytes - 1;
    426                         default_offset += offset;
    427                         goto_set.set(default_offset);
    428                         for (int j = 0; j < npairs; j++) {
    429                             int match = bytes.readInt();
    430                             index = offset + bytes.readInt();
    431                             goto_set.set(index);
    432                         }
    433                     }
    434                     break;
    435                 case GOTO:
    436                 case IFEQ:
    437                 case IFGE:
    438                 case IFGT:
    439                 case IFLE:
    440                 case IFLT:
    441                 case IFNE:
    442                 case IFNONNULL:
    443                 case IFNULL:
    444                 case IF_ACMPEQ:
    445                 case IF_ACMPNE:
    446                 case IF_ICMPEQ:
    447                 case IF_ICMPGE:
    448                 case IF_ICMPGT:
    449                 case IF_ICMPLE:
    450                 case IF_ICMPLT:
    451                 case IF_ICMPNE:
    452                 case JSR:
    453                     //bytes.readByte(); // Skip already read byte
    454                     index = bytes.getIndex() + bytes.readShort() - 1;
    455                     goto_set.set(index);
    456                     break;
    457                 case GOTO_W:
    458                 case JSR_W:
    459                     //bytes.readByte(); // Skip already read byte
    460                     index = bytes.getIndex() + bytes.readInt() - 1;
    461                     goto_set.set(index);
    462                     break;
    463                 default:
    464                     bytes.unreadByte();
    465                     codeToHTML(bytes, 0); // Ignore output
    466             }
    467         }
    468     }
    469
    470
    471     /***
    472      * Write a single method with the byte code associated with it.
    473      */
    474     private void writeMethod( Method method, int method_number ) throws IOException {
    475         // Get raw signature
    476         String signature = method.getSignature();
    477         // Get array of strings containing the argument types
    478         String[] args = Utility.methodSignatureArgumentTypes(signature, false);
    479         // Get return type string
    480         String type = Utility.methodSignatureReturnType(signature, false);
    481         // Get method name
    482         String name = method.getName();
    483         String html_name = Class2HTML.toHTML(name);
    484         // Get method's access flags
    485         String access = Utility.accessToString(method.getAccessFlags());
    486         access = Utility.replace(access, " ", "&nbsp;");
    487         // Get the method's attributes, the Code Attribute in particular
    488         Attribute[] attributes = method.getAttributes();
    489         file.print("<P><B><FONT COLOR=\"#FF0000\">" + access + "</FONT>&nbsp;" + "<A NAME=method"
    490                 + method_number + ">" + Class2HTML.referenceType(type) + "</A>&nbsp<A HREF=\""
    491                 + class_name + "_methods.html#method" + method_number + "\" TARGET=Methods>"
    492                 + html_name + "</A>(");
    493         for (int i = 0; i < args.length; i++) {
    494             file.print(Class2HTML.referenceType(args[i]));
    495             if (i < args.length - 1) {
    496                 file.print(",&nbsp;");
    497             }
    498         }
    499         file.println(")</B></P>");
    500         Code c = null;
    501         byte[] code = null;
    502         if (attributes.length > 0) {
    503             file.print("<H4>Attributes</H4><UL>\n");
    504             for (int i = 0; i < attributes.length; i++) {
    505                 byte tag = attributes[i].getTag();
    506                 if (tag != ATTR_UNKNOWN) {
    507                     file.print("<LI><A HREF=\"" + class_name + "_attributes.html#method"
    508                             + method_number + "@" + i + "\" TARGET=Attributes>"
    509                             + ATTRIBUTE_NAMES[tag] + "</A></LI>\n");
    510                 } else {
    511                     file.print("<LI>" + attributes[i] + "</LI>");
    512                 }
    513                 if (tag == ATTR_CODE) {
    514                     c = (Code) attributes[i];
    515                     Attribute[] attributes2 = c.getAttributes();
    516                     code = c.getCode();
    517                     file.print("<UL>");
    518                     for (int j = 0; j < attributes2.length; j++) {
    519                         tag = attributes2[j].getTag();
    520                         file.print("<LI><A HREF=\"" + class_name + "_attributes.html#" + "method"
    521                                 + method_number + "@" + i + "@" + j + "\" TARGET=Attributes>"
    522                                 + ATTRIBUTE_NAMES[tag] + "</A></LI>\n");
    523                     }
    524                     file.print("</UL>");
    525                 }
    526             }
    527             file.println("</UL>");
    528         }
    529         if (code != null) { // No code, an abstract method, e.g.
    530             //System.out.println(name + "\n" + Utility.codeToString(code, constant_pool, 0, -1));
    531             // Print the byte code
    532             ByteSequence stream = new ByteSequence(code);
    533             stream.mark(stream.available());
    534             findGotos(stream, method, c);
    535             stream.reset();
    536             file.println("<TABLE BORDER=0><TR><TH ALIGN=LEFT>Byte<BR>offset</TH>"
    537                     + "<TH ALIGN=LEFT>Instruction</TH><TH ALIGN=LEFT>Argument</TH>");
    538             for (int i = 0; stream.available() > 0; i++) {
    539                 int offset = stream.getIndex();
    540                 String str = codeToHTML(stream, method_number);
    541                 String anchor = "";
    542                 /* Set an anchor mark if this line is targetted by a goto, jsr, etc.
    543                  * Defining an anchor for every line is very inefficient!
    544                  */
    545                 if (goto_set.get(offset)) {
    546                     anchor = "<A NAME=code" + method_number + "@" + offset + "></A>";
    547                 }
    548                 String anchor2;
    549                 if (stream.getIndex() == code.length) {
    550                     anchor2 = "<A NAME=code" + method_number + "@" + code.length + ">" + offset
    551                             + "</A>";
    552                 } else {
    553                     anchor2 = "" + offset;
    554                 }
    555                 file
    556                         .println("<TR VALIGN=TOP><TD>" + anchor2 + "</TD><TD>" + anchor + str
    557                                 + "</TR>");
    558             }
    559             // Mark last line, may be targetted from Attributes window
    560             file.println("<TR><TD> </A></TD></TR>");
    561             file.println("</TABLE>");
    562         }
    563     }
    564 }