vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java
author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
Wed, 03 Oct 2012 08:05:24 -0700
branchstrings
changeset 91 f3b685bd7243
parent 46 b07c7c256771
child 92 bf4f95784c62
permissions -rw-r--r--
Annotation to control conversion to JavaScript
     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.vm4brwsr;
    19 
    20 import java.io.IOException;
    21 import java.io.InputStream;
    22 import java.util.ArrayList;
    23 import java.util.Collection;
    24 import java.util.List;
    25 import org.apidesign.bck2brwsr.core.ExtraJavaScript;
    26 import org.netbeans.modules.classfile.Annotation;
    27 import org.netbeans.modules.classfile.AnnotationComponent;
    28 import static org.netbeans.modules.classfile.ByteCodes.*;
    29 import org.netbeans.modules.classfile.CPClassInfo;
    30 import org.netbeans.modules.classfile.CPEntry;
    31 import org.netbeans.modules.classfile.CPFieldInfo;
    32 import org.netbeans.modules.classfile.CPMethodInfo;
    33 import org.netbeans.modules.classfile.CPStringInfo;
    34 import org.netbeans.modules.classfile.ClassFile;
    35 import org.netbeans.modules.classfile.ClassName;
    36 import org.netbeans.modules.classfile.Code;
    37 import org.netbeans.modules.classfile.ElementValue;
    38 import org.netbeans.modules.classfile.Method;
    39 import org.netbeans.modules.classfile.Parameter;
    40 import org.netbeans.modules.classfile.PrimitiveElementValue;
    41 import org.netbeans.modules.classfile.Variable;
    42 
    43 /** Translator of the code inside class files to JavaScript.
    44  *
    45  * @author Jaroslav Tulach <jtulach@netbeans.org>
    46  */
    47 public final class ByteCodeToJavaScript {
    48     private final ClassFile jc;
    49     private final Appendable out;
    50     private final Collection<? super String> references;
    51 
    52     private ByteCodeToJavaScript(
    53         ClassFile jc, Appendable out, Collection<? super String> references
    54     ) {
    55         this.jc = jc;
    56         this.out = out;
    57         this.references = references;
    58     }
    59 
    60     /**
    61      * Converts a given class file to a JavaScript version.
    62      *
    63      * @param classFile input stream with code of the .class file
    64      * @param out a {@link StringBuilder} or similar to generate the output to
    65      * @param references a write only collection where the system adds list of
    66      *   other classes that were referenced and should be loaded in order the
    67      *   generated JavaScript code works properly. The names are in internal 
    68      *   JVM form so String is <code>java/lang/String</code>. Can be <code>null</code>
    69      *   if one is not interested in knowing references
    70      * @param scripts write only collection with names of resources to read
    71      * 
    72      * @throws IOException if something goes wrong during read or write or translating
    73      */
    74     
    75     public static void compile(
    76         InputStream classFile, Appendable out,
    77         Collection<? super String> references,
    78         Collection<? super String> scripts
    79     ) throws IOException {
    80         ClassFile jc = new ClassFile(classFile, true);
    81         final ClassName extraAnn = ClassName.getClassName(ExtraJavaScript.class.getName().replace('.', '/'));
    82         Annotation a = jc.getAnnotation(extraAnn);
    83         if (a != null) {
    84             final ElementValue annVal = a.getComponent("resource").getValue();
    85             String res = ((PrimitiveElementValue)annVal).getValue().getValue().toString();
    86             scripts.add(res);
    87             final AnnotationComponent process = a.getComponent("processByteCode");
    88             if (process != null && "false".equals(process.getValue().toString())) {
    89                 return;
    90             }
    91         }
    92         
    93         ByteCodeToJavaScript compiler = new ByteCodeToJavaScript(
    94             jc, out, references
    95         );
    96         List<String> toInitilize = new ArrayList<String>();
    97         for (Method m : jc.getMethods()) {
    98             if (m.isStatic()) {
    99                 compiler.generateStaticMethod(m, toInitilize);
   100             } else {
   101                 compiler.generateInstanceMethod(m);
   102             }
   103         }
   104         for (Variable v : jc.getVariables()) {
   105             if (v.isStatic()) {
   106                 compiler.generateStaticField(v);
   107             }
   108         }
   109         
   110         final String className = jc.getName().getInternalName().replace('/', '_');
   111         out.append("\nfunction ").append(className);
   112         out.append("() {");
   113         for (Variable v : jc.getVariables()) {
   114             if (!v.isStatic()) {
   115                 out.append("\n  this." + v.getName() + " = 0;");
   116             }
   117         }
   118         out.append("\n}");
   119         ClassName sc = jc.getSuperClass();
   120         if (sc != null) {
   121             out.append("\n").append(className)
   122                .append(".prototype = new ").append(sc.getInternalName().replace('/', '_')).append(';');
   123         }
   124         for (Method m : jc.getMethods()) {
   125             if (!m.isStatic() && !m.isPrivate() && !m.getName().contains("<init>")) {
   126                 compiler.generateMethodReference("\n" + className + ".prototype.", m);
   127             }
   128         }
   129         out.append("\n" + className + ".prototype.$instOf_").append(className).append(" = true;");
   130         for (ClassName superInterface : jc.getInterfaces()) {
   131             out.append("\n" + className + ".prototype.$instOf_").append(superInterface.getInternalName().replace('/', '_')).append(" = true;");
   132         }
   133         for (String init : toInitilize) {
   134             out.append("\n").append(init).append("();");
   135         }
   136     }
   137     private void generateStaticMethod(Method m, List<String> toInitilize) throws IOException {
   138         final String mn = findMethodName(m);
   139         out.append("\nfunction ").append(
   140             jc.getName().getInternalName().replace('/', '_')
   141         ).append('_').append(mn);
   142         if (mn.equals("classV")) {
   143             toInitilize.add(jc.getName().getInternalName().replace('/', '_') + '_' + mn);
   144         }
   145         out.append('(');
   146         String space = "";
   147         List<Parameter> args = m.getParameters();
   148         for (int index = 0, i = 0; i < args.size(); i++) {
   149             out.append(space);
   150             out.append("arg").append(String.valueOf(index));
   151             space = ",";
   152             final String desc = findDescriptor(args.get(i).getDescriptor());
   153             if ("D".equals(desc) || "J".equals(desc)) {
   154                 index += 2;
   155             } else {
   156                 index++;
   157             }
   158         }
   159         out.append(") {").append("\n");
   160         final Code code = m.getCode();
   161         if (code != null) {
   162             int len = code.getMaxLocals();
   163             for (int index = args.size(), i = args.size(); i < len; i++) {
   164                 out.append("  var ");
   165                 out.append("arg").append(String.valueOf(i)).append(";\n");
   166             }
   167             out.append("  var stack = new Array();\n");
   168             produceCode(code.getByteCodes());
   169         } else {
   170             out.append("  /* no code found for ").append(m.getTypeSignature()).append(" */\n");
   171         }
   172         out.append("}");
   173     }
   174     
   175     private void generateMethodReference(String prefix, Method m) throws IOException {
   176         final String name = findMethodName(m);
   177         out.append(prefix).append(name).append(" = ")
   178            .append(jc.getName().getInternalName().replace('/', '_'))
   179            .append('_').append(name).append(";");
   180     }
   181     
   182     private void generateInstanceMethod(Method m) throws IOException {
   183         out.append("\nfunction ").append(
   184             jc.getName().getInternalName().replace('/', '_')
   185         ).append('_').append(findMethodName(m));
   186         out.append("(arg0");
   187         String space = ",";
   188         List<Parameter> args = m.getParameters();
   189         for (int index = 1, i = 0; i < args.size(); i++) {
   190             out.append(space);
   191             out.append("arg").append(String.valueOf(index));
   192             final String desc = findDescriptor(args.get(i).getDescriptor());
   193             if ("D".equals(desc) || "J".equals(desc)) {
   194                 index += 2;
   195             } else {
   196                 index++;
   197             }
   198         }
   199         out.append(") {").append("\n");
   200         final Code code = m.getCode();
   201         if (code != null) {
   202             int len = code.getMaxLocals();
   203             for (int index = args.size(), i = args.size(); i < len; i++) {
   204                 out.append("  var ");
   205                 out.append("arg").append(String.valueOf(i + 1)).append(";\n");
   206             }
   207             out.append(";\n  var stack = new Array(");
   208             out.append(Integer.toString(code.getMaxStack()));
   209             out.append(");\n");
   210             produceCode(code.getByteCodes());
   211         } else {
   212             out.append("  /* no code found for ").append(m.getTypeSignature()).append(" */\n");
   213         }
   214         out.append("}");
   215     }
   216 
   217     private void produceCode(byte[] byteCodes) throws IOException {
   218         out.append("\n  var gt = 0;\n  for(;;) switch(gt) {\n");
   219         for (int i = 0; i < byteCodes.length; i++) {
   220             int prev = i;
   221             out.append("    case " + i).append(": ");
   222             final int c = (byteCodes[i] + 256) % 256;
   223             switch (c) {
   224                 case bc_aload_0:
   225                 case bc_iload_0:
   226                 case bc_lload_0:
   227                 case bc_fload_0:
   228                 case bc_dload_0:
   229                     out.append("stack.push(arg0);");
   230                     break;
   231                 case bc_aload_1:
   232                 case bc_iload_1:
   233                 case bc_lload_1:
   234                 case bc_fload_1:
   235                 case bc_dload_1:
   236                     out.append("stack.push(arg1);");
   237                     break;
   238                 case bc_aload_2:
   239                 case bc_iload_2:
   240                 case bc_lload_2:
   241                 case bc_fload_2:
   242                 case bc_dload_2:
   243                     out.append("stack.push(arg2);");
   244                     break;
   245                 case bc_aload_3:
   246                 case bc_iload_3:
   247                 case bc_lload_3:
   248                 case bc_fload_3:
   249                 case bc_dload_3:
   250                     out.append("stack.push(arg3);");
   251                     break;
   252                 case bc_iload:
   253                 case bc_lload:
   254                 case bc_fload:
   255                 case bc_dload:
   256                 case bc_aload: {
   257                     final int indx = (byteCodes[++i] + 256) % 256;
   258                     out.append("stack.push(arg").append(indx + ");");
   259                     break;
   260                 }
   261                 case bc_istore:
   262                 case bc_lstore:
   263                 case bc_fstore:
   264                 case bc_dstore:
   265                 case bc_astore: {
   266                     final int indx = (byteCodes[++i] + 256) % 256;
   267                     out.append("arg" + indx).append(" = stack.pop()");
   268                     break;
   269                 }
   270                 case bc_astore_0:
   271                 case bc_istore_0:
   272                 case bc_lstore_0:
   273                 case bc_fstore_0:
   274                 case bc_dstore_0:
   275                     out.append("arg0 = stack.pop();");
   276                     break;
   277                 case bc_astore_1:
   278                 case bc_istore_1:
   279                 case bc_lstore_1:
   280                 case bc_fstore_1:
   281                 case bc_dstore_1:
   282                     out.append("arg1 = stack.pop();");
   283                     break;
   284                 case bc_astore_2:
   285                 case bc_istore_2:
   286                 case bc_lstore_2:
   287                 case bc_fstore_2:
   288                 case bc_dstore_2:
   289                     out.append("arg2 = stack.pop();");
   290                     break;
   291                 case bc_astore_3:
   292                 case bc_istore_3:
   293                 case bc_lstore_3:
   294                 case bc_fstore_3:
   295                 case bc_dstore_3:
   296                     out.append("arg3 = stack.pop();");
   297                     break;
   298                 case bc_iadd:
   299                 case bc_ladd:
   300                 case bc_fadd:
   301                 case bc_dadd:
   302                     out.append("stack.push(stack.pop() + stack.pop());");
   303                     break;
   304                 case bc_isub:
   305                 case bc_lsub:
   306                 case bc_fsub:
   307                 case bc_dsub:
   308                     out.append("{ var tmp = stack.pop(); stack.push(stack.pop() - tmp); }");
   309                     break;
   310                 case bc_imul:
   311                 case bc_lmul:
   312                 case bc_fmul:
   313                 case bc_dmul:
   314                     out.append("stack.push(stack.pop() * stack.pop());");
   315                     break;
   316                 case bc_idiv:
   317                 case bc_ldiv:
   318                     out.append("{ var tmp = stack.pop(); stack.push(Math.floor(stack.pop() / tmp)); }");
   319                     break;
   320                 case bc_fdiv:
   321                 case bc_ddiv:
   322                     out.append("{ var tmp = stack.pop(); stack.push(stack.pop() / tmp); }");
   323                     break;
   324                 case bc_iand:
   325                 case bc_land:
   326                     out.append("stack.push(stack.pop() & stack.pop());");
   327                     break;
   328                 case bc_ior:
   329                 case bc_lor:
   330                     out.append("stack.push(stack.pop() | stack.pop());");
   331                     break;
   332                 case bc_ixor:
   333                 case bc_lxor:
   334                     out.append("stack.push(stack.pop() ^ stack.pop());");
   335                     break;
   336                 case bc_iinc: {
   337                     final int varIndx = (byteCodes[++i] + 256) % 256;
   338                     final int incrBy = (byteCodes[++i] + 256) % 256;
   339                     if (incrBy == 1) {
   340                         out.append("arg" + varIndx).append("++;");
   341                     } else {
   342                         out.append("arg" + varIndx).append(" += " + incrBy).append(";");
   343                     }
   344                     break;
   345                 }
   346                 case bc_return:
   347                     out.append("return;");
   348                     break;
   349                 case bc_ireturn:
   350                 case bc_lreturn:
   351                 case bc_freturn:
   352                 case bc_dreturn:
   353                 case bc_areturn:
   354                     out.append("return stack.pop();");
   355                     break;
   356                 case bc_i2l:
   357                 case bc_i2f:
   358                 case bc_i2d:
   359                 case bc_l2i:
   360                     // max int check?
   361                 case bc_l2f:
   362                 case bc_l2d:
   363                 case bc_f2d:
   364                 case bc_d2f:
   365                     out.append("/* number conversion */");
   366                     break;
   367                 case bc_f2i:
   368                 case bc_f2l:
   369                 case bc_d2i:
   370                 case bc_d2l:
   371                     out.append("stack.push(Math.floor(stack.pop()));");
   372                     break;
   373                 case bc_i2b:
   374                 case bc_i2c:
   375                 case bc_i2s:
   376                     out.append("/* number conversion */");
   377                     break;
   378                 case bc_aconst_null:
   379                     out.append("stack.push(null);");
   380                     break;
   381                 case bc_iconst_0:
   382                 case bc_dconst_0:
   383                 case bc_lconst_0:
   384                 case bc_fconst_0:
   385                     out.append("stack.push(0);");
   386                     break;
   387                 case bc_iconst_1:
   388                 case bc_lconst_1:
   389                 case bc_fconst_1:
   390                 case bc_dconst_1:
   391                     out.append("stack.push(1);");
   392                     break;
   393                 case bc_iconst_2:
   394                 case bc_fconst_2:
   395                     out.append("stack.push(2);");
   396                     break;
   397                 case bc_iconst_3:
   398                     out.append("stack.push(3);");
   399                     break;
   400                 case bc_iconst_4:
   401                     out.append("stack.push(4);");
   402                     break;
   403                 case bc_iconst_5:
   404                     out.append("stack.push(5);");
   405                     break;
   406                 case bc_ldc: {
   407                     int indx = byteCodes[++i];
   408                     CPEntry entry = jc.getConstantPool().get(indx);
   409                     String v = encodeConstant(entry);
   410                     out.append("stack.push(").append(v).append(");");
   411                     break;
   412                 }
   413                 case bc_ldc_w:
   414                 case bc_ldc2_w: {
   415                     int indx = readIntArg(byteCodes, i);
   416                     CPEntry entry = jc.getConstantPool().get(indx);
   417                     i += 2;
   418                     String v = encodeConstant(entry);
   419                     out.append("stack.push(").append(v).append(");");
   420                     break;
   421                 }
   422                 case bc_lcmp:
   423                 case bc_fcmpl:
   424                 case bc_fcmpg:
   425                 case bc_dcmpl:
   426                 case bc_dcmpg: {
   427                     out.append("{ var delta = stack.pop() - stack.pop(); stack.push(delta < 0 ?-1 : (delta == 0 ? 0 : 1)); }");
   428                     break;
   429                 }
   430                 case bc_if_icmpeq: {
   431                     i = generateIf(byteCodes, i, "==");
   432                     break;
   433                 }
   434                 case bc_ifeq: {
   435                     int indx = i + readIntArg(byteCodes, i);
   436                     out.append("if (stack.pop() == 0) { gt = " + indx);
   437                     out.append("; continue; }");
   438                     i += 2;
   439                     break;
   440                 }
   441                 case bc_ifne: {
   442                     int indx = i + readIntArg(byteCodes, i);
   443                     out.append("if (stack.pop() != 0) { gt = " + indx);
   444                     out.append("; continue; }");
   445                     i += 2;
   446                     break;
   447                 }
   448                 case bc_iflt: {
   449                     int indx = i + readIntArg(byteCodes, i);
   450                     out.append("if (stack.pop() < 0) { gt = " + indx);
   451                     out.append("; continue; }");
   452                     i += 2;
   453                     break;
   454                 }
   455                 case bc_ifle: {
   456                     int indx = i + readIntArg(byteCodes, i);
   457                     out.append("if (stack.pop() <= 0) { gt = " + indx);
   458                     out.append("; continue; }");
   459                     i += 2;
   460                     break;
   461                 }
   462                 case bc_ifgt: {
   463                     int indx = i + readIntArg(byteCodes, i);
   464                     out.append("if (stack.pop() > 0) { gt = " + indx);
   465                     out.append("; continue; }");
   466                     i += 2;
   467                     break;
   468                 }
   469                 case bc_ifge: {
   470                     int indx = i + readIntArg(byteCodes, i);
   471                     out.append("if (stack.pop() >= 0) { gt = " + indx);
   472                     out.append("; continue; }");
   473                     i += 2;
   474                     break;
   475                 }
   476                 case bc_ifnonnull: {
   477                     int indx = i + readIntArg(byteCodes, i);
   478                     out.append("if (stack.pop()) { gt = " + indx);
   479                     out.append("; continue; }");
   480                     i += 2;
   481                     break;
   482                 }
   483                 case bc_ifnull: {
   484                     int indx = i + readIntArg(byteCodes, i);
   485                     out.append("if (!stack.pop()) { gt = " + indx);
   486                     out.append("; continue; }");
   487                     i += 2;
   488                     break;
   489                 }
   490                 case bc_if_icmpne:
   491                     i = generateIf(byteCodes, i, "!=");
   492                     break;
   493                 case bc_if_icmplt:
   494                     i = generateIf(byteCodes, i, ">");
   495                     break;
   496                 case bc_if_icmple:
   497                     i = generateIf(byteCodes, i, ">=");
   498                     break;
   499                 case bc_if_icmpgt:
   500                     i = generateIf(byteCodes, i, "<");
   501                     break;
   502                 case bc_if_icmpge:
   503                     i = generateIf(byteCodes, i, "<=");
   504                     break;
   505                 case bc_goto: {
   506                     int indx = i + readIntArg(byteCodes, i);
   507                     out.append("gt = " + indx).append("; continue;");
   508                     i += 2;
   509                     break;
   510                 }
   511                 case bc_invokeinterface: {
   512                     i = invokeVirtualMethod(byteCodes, i) + 2;
   513                     break;
   514                 }
   515                 case bc_invokevirtual:
   516                     i = invokeVirtualMethod(byteCodes, i);
   517                     break;
   518                 case bc_invokespecial:
   519                     i = invokeStaticMethod(byteCodes, i, false);
   520                     break;
   521                 case bc_invokestatic:
   522                     i = invokeStaticMethod(byteCodes, i, true);
   523                     break;
   524                 case bc_new: {
   525                     int indx = readIntArg(byteCodes, i);
   526                     CPClassInfo ci = jc.getConstantPool().getClass(indx);
   527                     out.append("stack.push(");
   528                     out.append("new ").append(ci.getClassName().getInternalName().replace('/','_'));
   529                     out.append(");");
   530                     addReference(ci.getClassName().getInternalName());
   531                     i += 2;
   532                     break;
   533                 }
   534                 case bc_newarray: {
   535                     int type = byteCodes[i++];
   536                     out.append("stack.push(new Array(stack.pop()));");
   537                     break;
   538                 }
   539                 case bc_anewarray: {
   540                     i += 2; // skip type of array
   541                     out.append("stack.push(new Array(stack.pop()));");
   542                     break;
   543                 }
   544                 case bc_arraylength:
   545                     out.append("stack.push(stack.pop().length);");
   546                     break;
   547                 case bc_iastore:
   548                 case bc_lastore:
   549                 case bc_fastore:
   550                 case bc_dastore:
   551                 case bc_aastore:
   552                 case bc_bastore:
   553                 case bc_castore:
   554                 case bc_sastore: {
   555                     out.append("{ var value = stack.pop(); var indx = stack.pop(); stack.pop()[indx] = value; }");
   556                     break;
   557                 }
   558                 case bc_iaload:
   559                 case bc_laload:
   560                 case bc_faload:
   561                 case bc_daload:
   562                 case bc_aaload:
   563                 case bc_baload:
   564                 case bc_caload:
   565                 case bc_saload: {
   566                     out.append("{ var indx = stack.pop(); stack.push(stack.pop()[indx]); }");
   567                     break;
   568                 }
   569                 case bc_dup:
   570                     out.append("stack.push(stack[stack.length - 1]);");
   571                     break;
   572                 case bc_bipush:
   573                     out.append("stack.push(" + byteCodes[++i] + ");");
   574                     break;
   575                 case bc_sipush:
   576                     out.append("stack.push(" + readIntArg(byteCodes, i) + ");");
   577                     i += 2;
   578                     break;
   579                 case bc_getfield: {
   580                     int indx = readIntArg(byteCodes, i);
   581                     CPFieldInfo fi = (CPFieldInfo) jc.getConstantPool().get(indx);
   582                     out.append("stack.push(stack.pop().").append(fi.getFieldName()).append(");");
   583                     i += 2;
   584                     break;
   585                 }
   586                 case bc_getstatic: {
   587                     int indx = readIntArg(byteCodes, i);
   588                     CPFieldInfo fi = (CPFieldInfo) jc.getConstantPool().get(indx);
   589                     final String in = fi.getClassName().getInternalName();
   590                     out.append("stack.push(").append(in.replace('/', '_'));
   591                     out.append('_').append(fi.getFieldName()).append(");");
   592                     i += 2;
   593                     addReference(in);
   594                     break;
   595                 }
   596                 case bc_putstatic: {
   597                     int indx = readIntArg(byteCodes, i);
   598                     CPFieldInfo fi = (CPFieldInfo) jc.getConstantPool().get(indx);
   599                     final String in = fi.getClassName().getInternalName();
   600                     out.append(in.replace('/', '_'));
   601                     out.append('_').append(fi.getFieldName()).append(" = stack.pop();");
   602                     i += 2;
   603                     addReference(in);
   604                     break;
   605                 }
   606                 case bc_putfield: {
   607                     int indx = readIntArg(byteCodes, i);
   608                     CPFieldInfo fi = (CPFieldInfo) jc.getConstantPool().get(indx);
   609                     out.append("{ var v = stack.pop(); stack.pop().")
   610                        .append(fi.getFieldName()).append(" = v; }");
   611                     i += 2;
   612                     break;
   613                 }
   614                 case bc_checkcast: {
   615                     int indx = readIntArg(byteCodes, i);
   616                     CPClassInfo ci = jc.getConstantPool().getClass(indx);
   617                     final String type = ci.getClassName().getType();
   618                     if (!type.startsWith("[")) {
   619                         // no way to check arrays right now
   620                         out.append("if(stack[stack.length - 1].$instOf_")
   621                            .append(type.replace('/', '_'))
   622                            .append(" != 1) throw {};"); // XXX proper exception
   623                     }
   624                     i += 2;
   625                     break;
   626                 }
   627                 case bc_instanceof: {
   628                     int indx = readIntArg(byteCodes, i);
   629                     CPClassInfo ci = jc.getConstantPool().getClass(indx);
   630                     out.append("stack.push(stack.pop().$instOf_")
   631                        .append(ci.getClassName().getInternalName().replace('/', '_'))
   632                        .append(" ? 1 : 0);");
   633                     i += 2;
   634                     break;
   635                 }
   636                     
   637             }
   638             out.append(" //");
   639             for (int j = prev; j <= i; j++) {
   640                 out.append(" ");
   641                 final int cc = (byteCodes[j] + 256) % 256;
   642                 out.append(Integer.toString(cc));
   643             }
   644             out.append("\n");
   645         }
   646         out.append("  }\n");
   647     }
   648 
   649     private int generateIf(byte[] byteCodes, int i, final String test) throws IOException {
   650         int indx = i + readIntArg(byteCodes, i);
   651         out.append("if (stack.pop() ").append(test).append(" stack.pop()) { gt = " + indx);
   652         out.append("; continue; }");
   653         return i + 2;
   654     }
   655 
   656     private int readIntArg(byte[] byteCodes, int offsetInstruction) {
   657         final int indxHi = byteCodes[offsetInstruction + 1] << 8;
   658         final int indxLo = byteCodes[offsetInstruction + 2];
   659         return (indxHi & 0xffffff00) | (indxLo & 0xff);
   660     }
   661     
   662     private static int countArgs(String descriptor, boolean[] hasReturnType, StringBuilder sig) {
   663         int cnt = 0;
   664         int i = 0;
   665         Boolean count = null;
   666         boolean array = false;
   667         int firstPos = sig.length();
   668         while (i < descriptor.length()) {
   669             char ch = descriptor.charAt(i++);
   670             switch (ch) {
   671                 case '(':
   672                     count = true;
   673                     continue;
   674                 case ')':
   675                     count = false;
   676                     continue;
   677                 case 'A':
   678                     array = true;
   679                     break;
   680                 case 'B': 
   681                 case 'C': 
   682                 case 'D': 
   683                 case 'F': 
   684                 case 'I': 
   685                 case 'J': 
   686                 case 'S': 
   687                 case 'Z': 
   688                     if (count) {
   689                         cnt++;
   690                         if (array) {
   691                             sig.append('A');
   692                         }
   693                         sig.append(ch);
   694                     } else {
   695                         hasReturnType[0] = true;
   696                         sig.insert(firstPos, ch);
   697                         if (array) {
   698                             sig.insert(firstPos, 'A');
   699                         }
   700                     }
   701                     continue;
   702                 case 'V': 
   703                     assert !count;
   704                     hasReturnType[0] = false;
   705                     sig.insert(firstPos, 'V');
   706                     continue;
   707                 case 'L':
   708                     int next = descriptor.indexOf(';', i);
   709                     if (count) {
   710                         cnt++;
   711                         if (array) {
   712                             sig.append('A');
   713                         }
   714                         sig.append(ch);
   715                         sig.append(descriptor.substring(i, next).replace('/', '_'));
   716                     } else {
   717                         sig.insert(firstPos, descriptor.substring(i, next).replace('/', '_'));
   718                         sig.insert(firstPos, ch);
   719                         if (array) {
   720                             sig.insert(firstPos, 'A');
   721                         }
   722                         hasReturnType[0] = true;
   723                     }
   724                     i = next + 1;
   725                     continue;
   726                 case '[':
   727                     //arrays++;
   728                     continue;
   729                 default:
   730                     break; // invalid character
   731             }
   732         }
   733         return cnt;
   734     }
   735 
   736     private void generateStaticField(Variable v) throws IOException {
   737         out.append("\nvar ")
   738            .append(jc.getName().getInternalName().replace('/', '_'))
   739            .append('_').append(v.getName()).append(" = 0;");
   740     }
   741 
   742     private String findMethodName(Method m) {
   743         StringBuilder name = new StringBuilder();
   744         String descr = m.getDescriptor();
   745         if ("<init>".equals(m.getName())) { // NOI18N
   746             name.append("cons"); // NOI18N
   747         } else if ("<clinit>".equals(m.getName())) { // NOI18N
   748             name.append("class"); // NOI18N
   749         } else {
   750             name.append(m.getName());
   751         } 
   752         
   753         boolean hasReturn[] = { false };
   754         countArgs(findDescriptor(m.getDescriptor()), hasReturn, name);
   755         return name.toString();
   756     }
   757 
   758     private String findMethodName(CPMethodInfo mi, int[] cnt, boolean[] hasReturn) {
   759         StringBuilder name = new StringBuilder();
   760         String descr = mi.getDescriptor();
   761         if ("<init>".equals(mi.getName())) { // NOI18N
   762             name.append("cons"); // NOI18N
   763         } else {
   764             name.append(mi.getName());
   765         }
   766         cnt[0] = countArgs(findDescriptor(mi.getDescriptor()), hasReturn, name);
   767         return name.toString();
   768     }
   769 
   770     private int invokeStaticMethod(byte[] byteCodes, int i, boolean isStatic)
   771     throws IOException {
   772         int methodIndex = readIntArg(byteCodes, i);
   773         CPMethodInfo mi = (CPMethodInfo) jc.getConstantPool().get(methodIndex);
   774         boolean[] hasReturn = { false };
   775         int[] cnt = { 0 };
   776         String mn = findMethodName(mi, cnt, hasReturn);
   777         out.append("{ ");
   778         for (int j = cnt[0] - 1; j >= 0; j--) {
   779             out.append("var v" + j).append(" = stack.pop(); ");
   780         }
   781         
   782         if (hasReturn[0]) {
   783             out.append("stack.push(");
   784         }
   785         final String in = mi.getClassName().getInternalName();
   786         out.append(in.replace('/', '_'));
   787         out.append('_');
   788         out.append(mn);
   789         out.append('(');
   790         String sep = "";
   791         if (!isStatic) {
   792             out.append("stack.pop()");
   793             sep = ", ";
   794         }
   795         for (int j = 0; j < cnt[0]; j++) {
   796             out.append(sep);
   797             out.append("v" + j);
   798             sep = ", ";
   799         }
   800         out.append(")");
   801         if (hasReturn[0]) {
   802             out.append(")");
   803         }
   804         out.append("; }");
   805         i += 2;
   806         addReference(in);
   807         return i;
   808     }
   809     private int invokeVirtualMethod(byte[] byteCodes, int i)
   810     throws IOException {
   811         int methodIndex = readIntArg(byteCodes, i);
   812         CPMethodInfo mi = (CPMethodInfo) jc.getConstantPool().get(methodIndex);
   813         boolean[] hasReturn = { false };
   814         int[] cnt = { 0 };
   815         String mn = findMethodName(mi, cnt, hasReturn);
   816         out.append("{ ");
   817         for (int j = cnt[0] - 1; j >= 0; j--) {
   818             out.append("var v" + j).append(" = stack.pop(); ");
   819         }
   820         out.append("var self = stack.pop(); ");
   821         if (hasReturn[0]) {
   822             out.append("stack.push(");
   823         }
   824         out.append("self.");
   825         out.append(mn);
   826         out.append('(');
   827         out.append("self");
   828         for (int j = 0; j < cnt[0]; j++) {
   829             out.append(", ");
   830             out.append("v" + j);
   831         }
   832         out.append(")");
   833         if (hasReturn[0]) {
   834             out.append(")");
   835         }
   836         out.append("; }");
   837         i += 2;
   838         return i;
   839     }
   840     
   841     private void addReference(String cn) {
   842         if (references != null) {
   843             references.add(cn);
   844         }
   845     }
   846 
   847     private void outType(String d, StringBuilder out) {
   848         int arr = 0;
   849         while (d.charAt(0) == '[') {
   850             out.append('A');
   851             d = d.substring(1);
   852         }
   853         if (d.charAt(0) == 'L') {
   854             assert d.charAt(d.length() - 1) == ';';
   855             out.append(d.replace('/', '_').substring(0, d.length() - 1));
   856         } else {
   857             out.append(d);
   858         }
   859     }
   860 
   861     private String encodeConstant(CPEntry entry) {
   862         final String v;
   863         if (entry instanceof CPStringInfo) {
   864             v = "\"" + entry.getValue().toString().replace("\"", "\\\"") + "\"";
   865         } else {
   866             v = entry.getValue().toString();
   867         }
   868         return v;
   869     }
   870 
   871     private String findDescriptor(String d) {
   872         return d.replace('[', 'A');
   873     }
   874 }