src/main/java/org/apidesign/java4browser/ByteCodeToJavaScript.java
author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
Thu, 20 Sep 2012 14:35:21 +0200
changeset 19 2291e553464a
parent 18 361b76189f8d
child 20 0e7dd9e2e31e
permissions -rw-r--r--
We can read definition of Object from the JDK. No need to provide default dummy implementation. InstanceSub is discovered automatically.
     1 /*
     2 Java 4 Browser Bytecode Translator
     3 Copyright (C) 2012-2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
     4 
     5 This program is free software: you can redistribute it and/or modify
     6 it under the terms of the GNU General Public License as published by
     7 the Free Software Foundation, version 2 of the License.
     8 
     9 This program is distributed in the hope that it will be useful,
    10 but WITHOUT ANY WARRANTY; without even the implied warranty of
    11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    12 GNU General Public License for more details.
    13 
    14 You should have received a copy of the GNU General Public License
    15 along with this program. Look for COPYING file in the top folder.
    16 If not, see http://opensource.org/licenses/GPL-2.0.
    17 */
    18 package org.apidesign.java4browser;
    19 
    20 import java.io.IOException;
    21 import java.io.InputStream;
    22 import java.util.Collection;
    23 import java.util.List;
    24 import static org.netbeans.modules.classfile.ByteCodes.*;
    25 import org.netbeans.modules.classfile.CPClassInfo;
    26 import org.netbeans.modules.classfile.CPEntry;
    27 import org.netbeans.modules.classfile.CPFieldInfo;
    28 import org.netbeans.modules.classfile.CPMethodInfo;
    29 import org.netbeans.modules.classfile.ClassFile;
    30 import org.netbeans.modules.classfile.ClassName;
    31 import org.netbeans.modules.classfile.Code;
    32 import org.netbeans.modules.classfile.Method;
    33 import org.netbeans.modules.classfile.Parameter;
    34 import org.netbeans.modules.classfile.Variable;
    35 
    36 /** Translator of the code inside class files to JavaScript.
    37  *
    38  * @author Jaroslav Tulach <jtulach@netbeans.org>
    39  */
    40 public final class ByteCodeToJavaScript {
    41     private final ClassFile jc;
    42     private final Appendable out;
    43     private final Collection<? super String> references;
    44 
    45     private ByteCodeToJavaScript(
    46         ClassFile jc, Appendable out, Collection<? super String> references
    47     ) {
    48         this.jc = jc;
    49         this.out = out;
    50         this.references = references;
    51     }
    52 
    53     /**
    54      * Converts a given class file to a JavaScript version.
    55      *
    56      * @param classFile input stream with code of the .class file
    57      * @param out a {@link StringBuilder} or similar to generate the output to
    58      * @param references a write only collection where the system adds list of
    59      *   other classes that were referenced and should be loaded in order the
    60      *   generated JavaScript code works properly. The names are in internal 
    61      *   JVM form so String is <code>java/lang/String</code>. Can be <code>null</code>
    62      *   if one is not interested in knowing references
    63      * @throws IOException if something goes wrong during read or write or translating
    64      */
    65     
    66     public static void compile(
    67         InputStream classFile, Appendable out,
    68         Collection<? super String> references
    69     ) throws IOException {
    70         ClassFile jc = new ClassFile(classFile, true);
    71         ByteCodeToJavaScript compiler = new ByteCodeToJavaScript(
    72             jc, out, references
    73         );
    74         for (Method m : jc.getMethods()) {
    75             if (m.isStatic()) {
    76                 compiler.generateStaticMethod(m);
    77             } else {
    78                 compiler.generateInstanceMethod(m);
    79             }
    80         }
    81         for (Variable v : jc.getVariables()) {
    82             if (v.isStatic()) {
    83                 compiler.generateStaticField(v);
    84             }
    85         }
    86         
    87         final String className = jc.getName().getInternalName().replace('/', '_');
    88         out.append("\nfunction ").append(className);
    89         out.append("() {");
    90         for (Method m : jc.getMethods()) {
    91             if (!m.isStatic()) {
    92                 compiler.generateMethodReference(m);
    93             }
    94         }
    95         for (Variable v : jc.getVariables()) {
    96             if (!v.isStatic()) {
    97                 out.append("\n  this." + v.getName() + " = 0;");
    98             }
    99         }
   100         out.append("\n  this.$instOf_").append(className).append(" = true;");
   101         out.append("\n}");
   102         ClassName sc = jc.getSuperClass();
   103         if (sc != null) {
   104             out.append("\n  ").append(className)
   105                .append(".prototype = new ").append(sc.getInternalName().replace('/', '_'));
   106         }
   107     }
   108     private void generateStaticMethod(Method m) throws IOException {
   109         out.append("\nfunction ").append(
   110             jc.getName().getInternalName().replace('/', '_')
   111         ).append('_').append(findMethodName(m));
   112         out.append('(');
   113         String space = "";
   114         List<Parameter> args = m.getParameters();
   115         for (int index = 0, i = 0; i < args.size(); i++) {
   116             out.append(space);
   117             out.append("arg").append(String.valueOf(index));
   118             space = ",";
   119             final String desc = args.get(i).getDescriptor();
   120             if ("D".equals(desc) || "J".equals(desc)) {
   121                 index += 2;
   122             } else {
   123                 index++;
   124             }
   125         }
   126         out.append(") {").append("\n");
   127         final Code code = m.getCode();
   128         if (code != null) {
   129             int len = code.getMaxLocals();
   130             for (int index = args.size(), i = args.size(); i < len; i++) {
   131                 out.append("  var ");
   132                 out.append("arg").append(String.valueOf(i)).append(";\n");
   133             }
   134             out.append("  var stack = new Array(");
   135             out.append(Integer.toString(code.getMaxStack()));
   136             out.append(");\n");
   137             produceCode(code.getByteCodes());
   138         } else {
   139             out.append("  /* no code found for ").append(m.getTypeSignature()).append(" */\n");
   140         }
   141         out.append("}");
   142     }
   143     
   144     private void generateMethodReference(Method m) throws IOException {
   145         final String name = findMethodName(m);
   146         out.append("\n  this.").append(name).append(" = ")
   147            .append(jc.getName().getInternalName().replace('/', '_'))
   148            .append('_').append(name).append(";");
   149     }
   150     
   151     private void generateInstanceMethod(Method m) throws IOException {
   152         out.append("\nfunction ").append(
   153             jc.getName().getInternalName().replace('/', '_')
   154         ).append('_').append(findMethodName(m));
   155         out.append("(arg0");
   156         String space = ",";
   157         List<Parameter> args = m.getParameters();
   158         for (int index = 1, i = 0; i < args.size(); i++) {
   159             out.append(space);
   160             out.append("arg").append(String.valueOf(index));
   161             final String desc = args.get(i).getDescriptor();
   162             if ("D".equals(desc) || "J".equals(desc)) {
   163                 index += 2;
   164             } else {
   165                 index++;
   166             }
   167         }
   168         out.append(") {").append("\n");
   169         final Code code = m.getCode();
   170         if (code != null) {
   171             int len = code.getMaxLocals();
   172             for (int index = args.size(), i = args.size(); i < len; i++) {
   173                 out.append("  var ");
   174                 out.append("arg").append(String.valueOf(i + 1)).append(";\n");
   175             }
   176             out.append(";\n  var stack = new Array(");
   177             out.append(Integer.toString(code.getMaxStack()));
   178             out.append(");\n");
   179             produceCode(code.getByteCodes());
   180         } else {
   181             out.append("  /* no code found for ").append(m.getTypeSignature()).append(" */\n");
   182         }
   183         out.append("}");
   184     }
   185 
   186     private void produceCode(byte[] byteCodes) throws IOException {
   187         out.append("\n  var gt = 0;\n  for(;;) switch(gt) {\n");
   188         for (int i = 0; i < byteCodes.length; i++) {
   189             int prev = i;
   190             out.append("    case " + i).append(": ");
   191             final int c = (byteCodes[i] + 256) % 256;
   192             switch (c) {
   193                 case bc_aload_0:
   194                 case bc_iload_0:
   195                 case bc_lload_0:
   196                 case bc_fload_0:
   197                 case bc_dload_0:
   198                     out.append("stack.push(arg0);");
   199                     break;
   200                 case bc_aload_1:
   201                 case bc_iload_1:
   202                 case bc_lload_1:
   203                 case bc_fload_1:
   204                 case bc_dload_1:
   205                     out.append("stack.push(arg1);");
   206                     break;
   207                 case bc_aload_2:
   208                 case bc_iload_2:
   209                 case bc_lload_2:
   210                 case bc_fload_2:
   211                 case bc_dload_2:
   212                     out.append("stack.push(arg2);");
   213                     break;
   214                 case bc_aload_3:
   215                 case bc_iload_3:
   216                 case bc_lload_3:
   217                 case bc_fload_3:
   218                 case bc_dload_3:
   219                     out.append("stack.push(arg3);");
   220                     break;
   221                 case bc_iload:
   222                 case bc_lload:
   223                 case bc_fload:
   224                 case bc_dload:
   225                 case bc_aload: {
   226                     final int indx = (byteCodes[++i] + 256) % 256;
   227                     out.append("stack.push(arg").append(indx + ");");
   228                     break;
   229                 }
   230                 case bc_astore_0:
   231                 case bc_istore_0:
   232                 case bc_lstore_0:
   233                 case bc_fstore_0:
   234                 case bc_dstore_0:
   235                     out.append("arg0 = stack.pop();");
   236                     break;
   237                 case bc_astore_1:
   238                 case bc_istore_1:
   239                 case bc_lstore_1:
   240                 case bc_fstore_1:
   241                 case bc_dstore_1:
   242                     out.append("arg1 = stack.pop();");
   243                     break;
   244                 case bc_astore_2:
   245                 case bc_istore_2:
   246                 case bc_lstore_2:
   247                 case bc_fstore_2:
   248                 case bc_dstore_2:
   249                     out.append("arg2 = stack.pop();");
   250                     break;
   251                 case bc_astore_3:
   252                 case bc_istore_3:
   253                 case bc_lstore_3:
   254                 case bc_fstore_3:
   255                 case bc_dstore_3:
   256                     out.append("arg3 = stack.pop();");
   257                     break;
   258                 case bc_iadd:
   259                 case bc_ladd:
   260                 case bc_fadd:
   261                 case bc_dadd:
   262                     out.append("stack.push(stack.pop() + stack.pop());");
   263                     break;
   264                 case bc_isub:
   265                 case bc_lsub:
   266                 case bc_fsub:
   267                 case bc_dsub:
   268                     out.append("{ var tmp = stack.pop(); stack.push(stack.pop() - tmp); }");
   269                     break;
   270                 case bc_imul:
   271                 case bc_lmul:
   272                 case bc_fmul:
   273                 case bc_dmul:
   274                     out.append("stack.push(stack.pop() * stack.pop());");
   275                     break;
   276                 case bc_idiv:
   277                 case bc_ldiv:
   278                     out.append("{ var tmp = stack.pop(); stack.push(Math.floor(stack.pop() / tmp)); }");
   279                     break;
   280                 case bc_fdiv:
   281                 case bc_ddiv:
   282                     out.append("{ var tmp = stack.pop(); stack.push(stack.pop() / tmp); }");
   283                     break;
   284                 case bc_iand:
   285                 case bc_land:
   286                     out.append("stack.push(stack.pop() & stack.pop());");
   287                     break;
   288                 case bc_ior:
   289                 case bc_lor:
   290                     out.append("stack.push(stack.pop() | stack.pop());");
   291                     break;
   292                 case bc_ixor:
   293                 case bc_lxor:
   294                     out.append("stack.push(stack.pop() ^ stack.pop());");
   295                     break;
   296                 case bc_iinc: {
   297                     final int varIndx = (byteCodes[++i] + 256) % 256;
   298                     final int incrBy = (byteCodes[++i] + 256) % 256;
   299                     if (incrBy == 1) {
   300                         out.append("arg" + varIndx).append("++;");
   301                     } else {
   302                         out.append("arg" + varIndx).append(" += " + incrBy).append(";");
   303                     }
   304                     break;
   305                 }
   306                 case bc_return:
   307                     out.append("return;");
   308                     break;
   309                 case bc_ireturn:
   310                 case bc_lreturn:
   311                 case bc_freturn:
   312                 case bc_dreturn:
   313                 case bc_areturn:
   314                     out.append("return stack.pop();");
   315                     break;
   316                 case bc_i2l:
   317                 case bc_i2f:
   318                 case bc_i2d:
   319                 case bc_l2i:
   320                     // max int check?
   321                 case bc_l2f:
   322                 case bc_l2d:
   323                 case bc_f2d:
   324                 case bc_d2f:
   325                     out.append("/* number conversion */");
   326                     break;
   327                 case bc_f2i:
   328                 case bc_f2l:
   329                 case bc_d2i:
   330                 case bc_d2l:
   331                     out.append("stack.push(Math.floor(stack.pop()));");
   332                     break;
   333                 case bc_i2b:
   334                 case bc_i2c:
   335                 case bc_i2s:
   336                     out.append("/* number conversion */");
   337                     break;
   338                 case bc_iconst_0:
   339                 case bc_dconst_0:
   340                 case bc_lconst_0:
   341                 case bc_fconst_0:
   342                     out.append("stack.push(0);");
   343                     break;
   344                 case bc_iconst_1:
   345                 case bc_lconst_1:
   346                 case bc_fconst_1:
   347                 case bc_dconst_1:
   348                     out.append("stack.push(1);");
   349                     break;
   350                 case bc_iconst_2:
   351                 case bc_fconst_2:
   352                     out.append("stack.push(2);");
   353                     break;
   354                 case bc_iconst_3:
   355                     out.append("stack.push(3);");
   356                     break;
   357                 case bc_iconst_4:
   358                     out.append("stack.push(4);");
   359                     break;
   360                 case bc_iconst_5:
   361                     out.append("stack.push(5);");
   362                     break;
   363                 case bc_ldc_w:
   364                 case bc_ldc2_w: {
   365                     int indx = readIntArg(byteCodes, i);
   366                     CPEntry entry = jc.getConstantPool().get(indx);
   367                     i += 2;
   368                     out.append("stack.push(" + entry.getValue() + ");");
   369                     break;
   370                 }
   371                 case bc_if_icmpeq: {
   372                     i = generateIf(byteCodes, i, "==");
   373                     break;
   374                 }
   375                 case bc_ifeq: {
   376                     int indx = i + readIntArg(byteCodes, i);
   377                     out.append("if (stack.pop() == 0) { gt = " + indx);
   378                     out.append("; continue; }");
   379                     i += 2;
   380                     break;
   381                 }
   382                 case bc_ifnonnull: {
   383                     int indx = i + readIntArg(byteCodes, i);
   384                     out.append("if (stack.pop()) { gt = " + indx);
   385                     out.append("; continue; }");
   386                     i += 2;
   387                     break;
   388                 }
   389                 case bc_ifnull: {
   390                     int indx = i + readIntArg(byteCodes, i);
   391                     out.append("if (!stack.pop()) { gt = " + indx);
   392                     out.append("; continue; }");
   393                     i += 2;
   394                     break;
   395                 }
   396                 case bc_if_icmpne:
   397                     i = generateIf(byteCodes, i, "!=");
   398                     break;
   399                 case bc_if_icmplt:
   400                     i = generateIf(byteCodes, i, ">");
   401                     break;
   402                 case bc_if_icmple:
   403                     i = generateIf(byteCodes, i, ">=");
   404                     break;
   405                 case bc_if_icmpgt:
   406                     i = generateIf(byteCodes, i, "<");
   407                     break;
   408                 case bc_if_icmpge:
   409                     i = generateIf(byteCodes, i, "<=");
   410                     break;
   411                 case bc_goto: {
   412                     int indx = i + readIntArg(byteCodes, i);
   413                     out.append("gt = " + indx).append("; continue;");
   414                     i += 2;
   415                     break;
   416                 }
   417                 case bc_invokeinterface:
   418                 case bc_invokevirtual:
   419                     i = invokeVirtualMethod(byteCodes, i);
   420                     break;
   421                 case bc_invokespecial:
   422                     i = invokeStaticMethod(byteCodes, i, false);
   423                     break;
   424                 case bc_invokestatic:
   425                     i = invokeStaticMethod(byteCodes, i, true);
   426                     break;
   427                 case bc_new: {
   428                     int indx = readIntArg(byteCodes, i);
   429                     CPClassInfo ci = jc.getConstantPool().getClass(indx);
   430                     out.append("stack.push(");
   431                     out.append("new ").append(ci.getClassName().getInternalName().replace('/','_'));
   432                     out.append(");");
   433                     addReference(ci.getClassName().getInternalName());
   434                     i += 2;
   435                     break;
   436                 }
   437                 case bc_dup:
   438                     out.append("stack.push(stack[stack.length - 1]);");
   439                     break;
   440                 case bc_bipush:
   441                     out.append("stack.push(" + byteCodes[++i] + ");");
   442                     break;
   443                 case bc_getfield: {
   444                     int indx = readIntArg(byteCodes, i);
   445                     CPFieldInfo fi = (CPFieldInfo) jc.getConstantPool().get(indx);
   446                     out.append(" stack.push(stack.pop().").append(fi.getFieldName()).append(");");
   447                     i += 2;
   448                     break;
   449                 }
   450                 case bc_getstatic: {
   451                     int indx = readIntArg(byteCodes, i);
   452                     CPFieldInfo fi = (CPFieldInfo) jc.getConstantPool().get(indx);
   453                     final String in = fi.getClassName().getInternalName();
   454                     out.append("stack.push(").append(in.replace('/', '_'));
   455                     out.append('_').append(fi.getFieldName()).append(");");
   456                     i += 2;
   457                     addReference(in);
   458                     break;
   459                 }
   460                 case bc_putstatic: {
   461                     int indx = readIntArg(byteCodes, i);
   462                     CPFieldInfo fi = (CPFieldInfo) jc.getConstantPool().get(indx);
   463                     final String in = fi.getClassName().getInternalName();
   464                     out.append(in.replace('/', '_'));
   465                     out.append('_').append(fi.getFieldName()).append(" = stack.pop();");
   466                     i += 2;
   467                     addReference(in);
   468                     break;
   469                 }
   470                 case bc_putfield: {
   471                     int indx = readIntArg(byteCodes, i);
   472                     CPFieldInfo fi = (CPFieldInfo) jc.getConstantPool().get(indx);
   473                     out.append("{ var v = stack.pop(); stack.pop().")
   474                        .append(fi.getFieldName()).append(" = v; }");
   475                     i += 2;
   476                     break;
   477                 }
   478                 case bc_instanceof: {
   479                     int indx = readIntArg(byteCodes, i);
   480                     CPClassInfo ci = jc.getConstantPool().getClass(indx);
   481                     out.append("stack.push(stack.pop().$instOf_")
   482                        .append(ci.getClassName().getInternalName().replace('/', '_'))
   483                        .append(" ? 1 : 0);");
   484                     i += 2;
   485                 }
   486                     
   487             }
   488             out.append(" /*");
   489             for (int j = prev; j <= i; j++) {
   490                 out.append(" ");
   491                 final int cc = (byteCodes[j] + 256) % 256;
   492                 out.append(Integer.toString(cc));
   493             }
   494             out.append("*/\n");
   495         }
   496         out.append("  }\n");
   497     }
   498 
   499     private int generateIf(byte[] byteCodes, int i, final String test) throws IOException {
   500         int indx = i + readIntArg(byteCodes, i);
   501         out.append("if (stack.pop() ").append(test).append(" stack.pop()) { gt = " + indx);
   502         out.append("; continue; }");
   503         return i + 2;
   504     }
   505 
   506     private int readIntArg(byte[] byteCodes, int offsetInstruction) {
   507         final int indxHi = byteCodes[offsetInstruction + 1] << 8;
   508         final int indxLo = byteCodes[offsetInstruction + 2];
   509         return (indxHi & 0xffffff00) | (indxLo & 0xff);
   510     }
   511     
   512     private static int countArgs(String descriptor, boolean[] hasReturnType, StringBuilder sig) {
   513         int cnt = 0;
   514         int i = 0;
   515         Boolean count = null;
   516         int firstPos = sig.length();
   517         while (i < descriptor.length()) {
   518             char ch = descriptor.charAt(i++);
   519             switch (ch) {
   520                 case '(':
   521                     count = true;
   522                     continue;
   523                 case ')':
   524                     count = false;
   525                     continue;
   526                 case 'B': 
   527                 case 'C': 
   528                 case 'D': 
   529                 case 'F': 
   530                 case 'I': 
   531                 case 'J': 
   532                 case 'S': 
   533                 case 'Z': 
   534                     if (count) {
   535                         cnt++;
   536                         sig.append(ch);
   537                     } else {
   538                         hasReturnType[0] = true;
   539                         sig.insert(firstPos, ch);
   540                     }
   541                     continue;
   542                 case 'V': 
   543                     assert !count;
   544                     hasReturnType[0] = false;
   545                     sig.insert(firstPos, 'V');
   546                     continue;
   547                 case 'L':
   548                     int next = descriptor.indexOf(';', i);
   549                     if (count) {
   550                         cnt++;
   551                         sig.append(ch);
   552                         sig.append(descriptor.substring(i, next).replace('/', '_'));
   553                     } else {
   554                         sig.insert(firstPos, descriptor.substring(i, next).replace('/', '_'));
   555                         sig.insert(firstPos, ch);
   556                         hasReturnType[0] = true;
   557                     }
   558                     i = next + 1;
   559                     continue;
   560                 case '[':
   561                     //arrays++;
   562                     continue;
   563                 default:
   564                     break; // invalid character
   565             }
   566         }
   567         return cnt;
   568     }
   569 
   570     private void generateStaticField(Variable v) throws IOException {
   571         out.append("\nvar ")
   572            .append(jc.getName().getInternalName().replace('/', '_'))
   573            .append('_').append(v.getName()).append(" = 0;");
   574     }
   575 
   576     private String findMethodName(Method m) {
   577         StringBuilder tmp = new StringBuilder();
   578         if ("<init>".equals(m.getName())) { // NOI18N
   579             tmp.append("consV"); // NOI18N
   580         } else if ("<clinit>".equals(m.getName())) { // NOI18N
   581             tmp.append("classV"); // NOI18N
   582         } else {
   583             tmp.append(m.getName());
   584             outType(m.getReturnType(), tmp);
   585         } 
   586         List<Parameter> args = m.getParameters();
   587         for (Parameter t : args) {
   588             outType(t.getDescriptor(), tmp);
   589         }
   590         return tmp.toString();
   591     }
   592 
   593     private String findMethodName(CPMethodInfo mi, int[] cnt, boolean[] hasReturn) {
   594         StringBuilder name = new StringBuilder();
   595         if ("<init>".equals(mi.getName())) { // NOI18N
   596             name.append("cons"); // NOI18N
   597         } else {
   598             name.append(mi.getName());
   599         }
   600         cnt[0] = countArgs(mi.getDescriptor(), hasReturn, name);
   601         return name.toString();
   602     }
   603 
   604     private int invokeStaticMethod(byte[] byteCodes, int i, boolean isStatic)
   605     throws IOException {
   606         int methodIndex = readIntArg(byteCodes, i);
   607         CPMethodInfo mi = (CPMethodInfo) jc.getConstantPool().get(methodIndex);
   608         boolean[] hasReturn = { false };
   609         int[] cnt = { 0 };
   610         String mn = findMethodName(mi, cnt, hasReturn);
   611         out.append("{ ");
   612         for (int j = cnt[0] - 1; j >= 0; j--) {
   613             out.append("var v" + j).append(" = stack.pop(); ");
   614         }
   615         
   616         if (hasReturn[0]) {
   617             out.append("stack.push(");
   618         }
   619         final String in = mi.getClassName().getInternalName();
   620         out.append(in.replace('/', '_'));
   621         out.append('_');
   622         out.append(mn);
   623         out.append('(');
   624         String sep = "";
   625         if (!isStatic) {
   626             out.append("stack.pop()");
   627             sep = ", ";
   628         }
   629         for (int j = 0; j < cnt[0]; j++) {
   630             out.append(sep);
   631             out.append("v" + j);
   632             sep = ", ";
   633         }
   634         out.append(")");
   635         if (hasReturn[0]) {
   636             out.append(")");
   637         }
   638         out.append("; }");
   639         i += 2;
   640         addReference(in);
   641         return i;
   642     }
   643     private int invokeVirtualMethod(byte[] byteCodes, int i)
   644     throws IOException {
   645         int methodIndex = readIntArg(byteCodes, i);
   646         CPMethodInfo mi = (CPMethodInfo) jc.getConstantPool().get(methodIndex);
   647         boolean[] hasReturn = { false };
   648         int[] cnt = { 0 };
   649         String mn = findMethodName(mi, cnt, hasReturn);
   650         out.append("{ ");
   651         for (int j = cnt[0] - 1; j >= 0; j--) {
   652             out.append("var v" + j).append(" = stack.pop(); ");
   653         }
   654         out.append("var self = stack.pop(); ");
   655         if (hasReturn[0]) {
   656             out.append("stack.push(");
   657         }
   658         out.append("self.");
   659         out.append(mn);
   660         out.append('(');
   661         out.append("self");
   662         for (int j = 0; j < cnt[0]; j++) {
   663             out.append(", ");
   664             out.append("v" + j);
   665         }
   666         out.append(")");
   667         if (hasReturn[0]) {
   668             out.append(")");
   669         }
   670         out.append("; }");
   671         i += 2;
   672         return i;
   673     }
   674     
   675     private void addReference(String cn) {
   676         if (references != null) {
   677             references.add(cn);
   678         }
   679     }
   680 
   681     private void outType(final String d, StringBuilder out) {
   682         if (d.charAt(0) == 'L') {
   683             assert d.charAt(d.length() - 1) == ';';
   684             out.append(d.replace('/', '_').substring(0, d.length() - 1));
   685         } else {
   686             out.append(d);
   687         }
   688     }
   689 }