Example usage for org.objectweb.asm Opcodes PUTFIELD

List of usage examples for org.objectweb.asm Opcodes PUTFIELD

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In this page you can find the example usage for org.objectweb.asm Opcodes PUTFIELD.

Prototype

int PUTFIELD

To view the source code for org.objectweb.asm Opcodes PUTFIELD.

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Usage

From source file:com.google.code.jconts.instrument.gen.ContinuationClassGenerator.java

License:Apache License

private void generateExecute(ClassVisitor cv, boolean execute) {
    final String name = info.continuationClassName;
    final Type outerType = Type.getObjectType(info.owner);

    // Generate invoke(T result);
    String signature = null;//  ww w. jav a 2  s .c  o  m
    if (execute) {
        SignatureWriter sign = new SignatureWriter();
        sign.visitParameterType().visitTypeVariable("T");
        sign.visitReturnType().visitBaseType('V'); // void
        signature = sign.toString();
    }
    MethodVisitor mv = cv.visitMethod(Opcodes.ACC_FINAL | Opcodes.ACC_PUBLIC,
            execute ? CONTINUATION_INVOKE_NAME : CONTINUATION_SET_EXCEPTION_NAME,
            execute ? CONTINUATION_INVOKE_DESC : CONTINUATION_SET_EXCEPTION_DESC, signature, null);
    mv.visitCode();
    Label start = new Label();
    Label end = new Label();
    mv.visitLabel(start);

    // Load outer this
    if (!info.isStatic()) {
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitFieldInsn(Opcodes.GETFIELD, name, "this$0", outerType.getDescriptor());
    }

    // state.result = result or state.exception = throwable
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitFieldInsn(Opcodes.GETFIELD, name, "state", stateDesc);
    mv.visitVarInsn(Opcodes.ALOAD, 1);
    mv.visitFieldInsn(Opcodes.PUTFIELD, info.stateClassName, execute ? "result" : "exception",
            execute ? OBJECT_DESC : THROWABLE_DESC);

    // Load state field
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitFieldInsn(Opcodes.GETFIELD, name, "state", stateDesc);

    // Continue from this index or index+1 (for exception)
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitFieldInsn(Opcodes.GETFIELD, name, "index", "I");
    if (!execute) {
        mv.visitInsn(Opcodes.ICONST_1);
        mv.visitInsn(Opcodes.IADD);
    }

    mv.visitMethodInsn(info.isStatic() ? Opcodes.INVOKESTATIC : Opcodes.INVOKEVIRTUAL, info.owner,
            info.name + "$async",
            Type.getMethodDescriptor(Type.VOID_TYPE, new Type[] { info.stateType, Type.INT_TYPE }));

    mv.visitInsn(Opcodes.RETURN);
    mv.visitLabel(end);

    mv.visitLocalVariable("this", 'L' + name + ';', signature, start, end, 0);
    if (!info.isStatic()) {
        mv.visitLocalVariable("this$0", outerType.getDescriptor(), null, start, end, 1);
    }
    mv.visitLocalVariable("result", OBJECT_DESC, "TT;", start, end, 1 + info.thisOffset);

    mv.visitMaxs(3 + info.thisOffset + (execute ? 0 : 1), 2 + info.thisOffset);
    mv.visitEnd();
}

From source file:com.google.code.jconts.instrument.gen.TramplineMethodGenerator.java

License:Apache License

public void accept(ClassVisitor cv) {
    MethodVisitor mv = cv.visitMethod(info.access, info.name, info.desc, info.signature, info.exceptions);
    mv.visitCode();/*from  ww  w.j  a  v a 2s. c o  m*/
    mv.visitTypeInsn(Opcodes.NEW, info.computationClassName);
    mv.visitInsn(Opcodes.DUP);

    // "this' for new Computation(this, state)
    if (!info.isStatic()) {
        mv.visitVarInsn(Opcodes.ALOAD, 0);
    }

    // new State()
    mv.visitTypeInsn(Opcodes.NEW, info.stateClassName);
    mv.visitInsn(Opcodes.DUP);
    mv.visitMethodInsn(Opcodes.INVOKESPECIAL, info.stateClassName, CTOR_NAME, DEFAULT_CTOR_DESC);

    // state.varX = argX
    String[] names = info.entryLocalsVars;
    for (int i = 0; i < info.entryLocals.length; ++i) {
        mv.visitInsn(Opcodes.DUP);
        mv.visitVarInsn(info.entryLocals[i].getOpcode(Opcodes.ILOAD), i + info.thisOffset);
        mv.visitFieldInsn(Opcodes.PUTFIELD, info.stateClassName, names[i], info.entryLocals[i].getDescriptor());
    }

    // new Computation(this, state);
    String ctorDesc;
    if (info.isStatic()) {
        ctorDesc = Type.getMethodDescriptor(Type.VOID_TYPE, new Type[] { info.stateType });
    } else {
        ctorDesc = Type.getMethodDescriptor(Type.VOID_TYPE,
                new Type[] { Type.getObjectType(info.owner), info.stateType });
    }
    mv.visitMethodInsn(Opcodes.INVOKESPECIAL, info.computationClassName, CTOR_NAME, ctorDesc);

    mv.visitInsn(Opcodes.ARETURN);
    mv.visitMaxs(info.isStatic() ? 5 : 6,
            info.isStatic() ? info.entryLocals.length : info.entryLocals.length + 1);
    mv.visitEnd();
}

From source file:com.google.devtools.build.android.desugar.BytecodeTypeInference.java

License:Open Source License

@Override
public void visitFieldInsn(int opcode, String owner, String name, String desc) {
    switch (opcode) {
    case Opcodes.GETSTATIC:
        pushDescriptor(desc);/*from   w  w  w.jav  a2  s  .  c  o  m*/
        break;
    case Opcodes.PUTSTATIC:
        popDescriptor(desc);
        break;
    case Opcodes.GETFIELD:
        pop();
        pushDescriptor(desc);
        break;
    case Opcodes.PUTFIELD:
        popDescriptor(desc);
        pop();
        break;
    default:
        throw new RuntimeException(
                "Unhandled opcode " + opcode + ", owner=" + owner + ", name=" + name + ", desc" + desc);
    }
    super.visitFieldInsn(opcode, owner, name, desc);
}

From source file:com.google.devtools.build.wireless.testing.java.injector.WhiteBoxMethodAdapter.java

License:Apache License

/**
 * Tells if the given instruction is corresponding to 
 * {@link Opcodes#PUTFIELD}.//from  ww  w  .j a v  a2  s .  c o m
 * 
 * @param opcode The given instruction;
 * @return <code>true</code> if the given instruction is 
 *    {@link Opcodes#PUTFIELD}, <code>false</code> otherwise.
 */
private boolean isField(int opcode) {
    return opcode == Opcodes.PUTFIELD;
}

From source file:com.google.test.metric.asm.MethodVisitorBuilder.java

License:Apache License

public void visitFieldInsn(final int opcode, String owner, final String name, final String desc) {
    owner = namer.nameClass(owner);/*from  ww w .ja  v a2s . c  o  m*/
    switch (opcode) {
    case Opcodes.PUTSTATIC:
        recorder.add(new PutFieldRunnable(repository, owner, name, desc, true));
        break;
    case Opcodes.PUTFIELD:
        recorder.add(new PutFieldRunnable(repository, owner, name, desc, false));
        break;
    case Opcodes.GETSTATIC:
        recorder.add(new GetFieldRunnable(repository, owner, name, desc, true));
        break;
    case Opcodes.GETFIELD:
        recorder.add(new GetFieldRunnable(repository, owner, name, desc, false));
        break;
    }
}

From source file:com.googlecode.ddom.weaver.compound.CompoundClassGenerator.java

License:Apache License

@Override
public void visitEnd() {
    for (int i = 0; i < componentClasses.length; i++) {
        String componentClass = Util.classNameToInternalName(componentClasses[i]);
        FieldVisitor fv = cv.visitField(Opcodes.ACC_PRIVATE, "c" + i, "L" + componentClass + ";", null, null);
        if (fv != null) {
            fv.visitEnd();//from  w  ww.  j  a va2 s .co m
        }
    }
    MethodVisitor mv = cv.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null, null);
    if (mv != null) {
        mv.visitCode();
        Label l0 = new Label();
        mv.visitLabel(l0);
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
        for (int i = 0; i < componentClasses.length; i++) {
            String componentClass = Util.classNameToInternalName(componentClasses[i]);
            mv.visitVarInsn(Opcodes.ALOAD, 0);
            mv.visitTypeInsn(Opcodes.NEW, componentClass);
            mv.visitInsn(Opcodes.DUP);
            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, componentClass, "<init>", "()V");
            mv.visitFieldInsn(Opcodes.PUTFIELD, className, "c" + i, "L" + componentClass + ";");
        }
        mv.visitInsn(Opcodes.RETURN);
        Label l1 = new Label();
        mv.visitLabel(l1);
        mv.visitLocalVariable("this", "L" + className + ";", null, l0, l1, 0);
        mv.visitMaxs(3, 1);
        mv.visitEnd();
    }
    cv.visitEnd();
}

From source file:com.googlecode.ddom.weaver.ext.ModelExtensionFactoryImplementation.java

License:Apache License

public void accept(ClassVisitor classVisitor) {
    // Note: the name chosen here must match what is expected in ExtensionFactoryLocator
    String name = Util.classNameToInternalName(implementationInfo.getFactoryInterface().getName() + "$$Impl");
    String factoryInterfaceName = Util
            .classNameToInternalName(implementationInfo.getFactoryInterface().getName());
    classVisitor.visit(Opcodes.V1_5, Opcodes.ACC_PUBLIC, name, null, "java/lang/Object",
            new String[] { factoryInterfaceName });
    {/*w  w  w  .j av a  2  s .c  o m*/
        FieldVisitor fw = classVisitor.visitField(Opcodes.ACC_PUBLIC | Opcodes.ACC_FINAL | Opcodes.ACC_STATIC,
                "INSTANCE", "L" + factoryInterfaceName + ";", null, null);
        if (fw != null) {
            fw.visitEnd();
        }
    }
    {
        FieldVisitor fw = classVisitor.visitField(Opcodes.ACC_PRIVATE | Opcodes.ACC_FINAL, "delegates",
                "Ljava/util/Map;", null, null);
        if (fw != null) {
            fw.visitEnd();
        }
    }
    {
        MethodVisitor mv = classVisitor.visitMethod(Opcodes.ACC_PRIVATE, "<init>", "()V", null, null);
        if (mv != null) {
            mv.visitCode();
            Label l0 = new Label();
            mv.visitLabel(l0);
            // Call constructor from superclass
            mv.visitVarInsn(Opcodes.ALOAD, 0);
            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
            // Create delegates map
            mv.visitVarInsn(Opcodes.ALOAD, 0);
            mv.visitTypeInsn(Opcodes.NEW, "java/util/HashMap");
            mv.visitInsn(Opcodes.DUP);
            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/util/HashMap", "<init>", "()V");
            mv.visitFieldInsn(Opcodes.PUTFIELD, name, "delegates", "Ljava/util/Map;");
            // Populate delegates map
            for (ModelExtensionInfo modelExtensionInfo : implementationInfo.getModelExtensions()) {
                for (ModelExtensionInterfaceInfo extensionInterface : modelExtensionInfo
                        .getExtensionInterfaces()) {
                    if (!extensionInterface.isAbstract()) {
                        // TODO: this is stupid; we should not recreate the info object here
                        ModelExtensionClassInfo modelExtensionClassInfo = new ModelExtensionClassInfo(
                                implementationInfo.getImplementation(), modelExtensionInfo.getRootInterface(),
                                extensionInterface);
                        String factoryDelegateImplName = Util.classNameToInternalName(
                                modelExtensionClassInfo.getFactoryDelegateImplementationClassName());
                        mv.visitVarInsn(Opcodes.ALOAD, 0);
                        mv.visitFieldInsn(Opcodes.GETFIELD, name, "delegates", "Ljava/util/Map;");
                        mv.visitLdcInsn(Type.getObjectType(Util.classNameToInternalName(
                                modelExtensionClassInfo.getExtensionInterface().getClassInfo().getName())));
                        mv.visitTypeInsn(Opcodes.NEW, factoryDelegateImplName);
                        mv.visitInsn(Opcodes.DUP);
                        mv.visitMethodInsn(Opcodes.INVOKESPECIAL, factoryDelegateImplName, "<init>", "()V");
                        mv.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/Map", "put",
                                "(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;");
                        mv.visitInsn(Opcodes.POP);
                    }
                }
            }
            mv.visitInsn(Opcodes.RETURN);
            Label l1 = new Label();
            mv.visitLabel(l1);
            mv.visitLocalVariable("this", "L" + name + ";", null, l0, l1, 0);
            mv.visitMaxs(4, 1);
            mv.visitEnd();
        }
    }
    String factoryDelegateInterfaceName = Util
            .classNameToInternalName(implementationInfo.getFactoryDelegateInterfaceName());
    String getDelegateDesc = "(Ljava/lang/Class;)L" + factoryDelegateInterfaceName + ";";
    {
        MethodVisitor mv = classVisitor.visitMethod(Opcodes.ACC_PRIVATE, "getDelegate", getDelegateDesc, null,
                null);
        if (mv != null) {
            mv.visitCode();
            Label l0 = new Label();
            mv.visitLabel(l0);
            mv.visitVarInsn(Opcodes.ALOAD, 0);
            mv.visitFieldInsn(Opcodes.GETFIELD, name, "delegates", "Ljava/util/Map;");
            mv.visitVarInsn(Opcodes.ALOAD, 1);
            mv.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/Map", "get",
                    "(Ljava/lang/Object;)Ljava/lang/Object;");
            mv.visitTypeInsn(Opcodes.CHECKCAST, factoryDelegateInterfaceName);
            mv.visitInsn(Opcodes.ARETURN);
            Label l1 = new Label();
            mv.visitLabel(l1);
            mv.visitLocalVariable("this", "L" + name + ";", null, l0, l1, 0);
            mv.visitLocalVariable("extensionInterface", "Ljava/lang/Class;", null, l0, l1, 1);
            mv.visitMaxs(2, 2);
            mv.visitEnd();
        }
    }
    String implementationName = Util.classNameToInternalName(implementationInfo.getImplementation().getName());
    for (ConstructorInfo constructor : implementationInfo.getConstructors()) {
        Type[] constructorArgumentTypes = constructor.getArgumentTypes();
        Type[] argumentTypes = new Type[constructorArgumentTypes.length + 1];
        argumentTypes[0] = Type.getObjectType("java/lang/Class");
        System.arraycopy(constructorArgumentTypes, 0, argumentTypes, 1, constructorArgumentTypes.length);
        MethodVisitor mv = classVisitor.visitMethod(Opcodes.ACC_PUBLIC, "create",
                Type.getMethodDescriptor(Type.getObjectType(implementationName), argumentTypes), null, null);
        if (mv != null) {
            mv.visitCode();
            Label l0 = new Label();
            mv.visitLabel(l0);
            mv.visitVarInsn(Opcodes.ALOAD, 1);
            Label l1 = new Label();
            mv.visitJumpInsn(Opcodes.IFNONNULL, l1);
            mv.visitTypeInsn(Opcodes.NEW, implementationName);
            mv.visitInsn(Opcodes.DUP);
            for (int i = 0; i < constructorArgumentTypes.length; i++) {
                mv.visitVarInsn(constructorArgumentTypes[i].getOpcode(Opcodes.ILOAD), i + 2);
            }
            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, implementationName, "<init>",
                    constructor.getDescriptor());
            mv.visitInsn(Opcodes.ARETURN);
            mv.visitLabel(l1);
            mv.visitVarInsn(Opcodes.ALOAD, 0);
            mv.visitVarInsn(Opcodes.ALOAD, 1);
            mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, name, "getDelegate", getDelegateDesc);
            for (int i = 0; i < constructorArgumentTypes.length; i++) {
                mv.visitVarInsn(constructorArgumentTypes[i].getOpcode(Opcodes.ILOAD), i + 2);
            }
            mv.visitMethodInsn(Opcodes.INVOKEINTERFACE, factoryDelegateInterfaceName, "create",
                    constructor.getFactoryDelegateMethodDescriptor());
            mv.visitInsn(Opcodes.ARETURN);
            Label l3 = new Label();
            mv.visitLabel(l3);
            mv.visitLocalVariable("this", "L" + name + ";", null, l0, l3, 0);
            mv.visitLocalVariable("extensionInterface", "Ljava/lang/Class;", null, l0, l3, 1);
            for (int i = 0; i < constructorArgumentTypes.length; i++) {
                mv.visitLocalVariable("arg" + i, constructorArgumentTypes[i].getDescriptor(), null, l0, l3,
                        i + 2);
            }
            mv.visitMaxs(argumentTypes.length + 1, argumentTypes.length + 1);
            mv.visitEnd();
        }
    }
    {
        MethodVisitor mv = classVisitor.visitMethod(Opcodes.ACC_STATIC, "<clinit>", "()V", null, null);
        if (mv != null) {
            mv.visitCode();
            mv.visitTypeInsn(Opcodes.NEW, name);
            mv.visitInsn(Opcodes.DUP);
            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, name, "<init>", "()V");
            mv.visitFieldInsn(Opcodes.PUTSTATIC, name, "INSTANCE", "L" + factoryInterfaceName + ";");
            mv.visitInsn(Opcodes.RETURN);
            mv.visitMaxs(2, 0);
            mv.visitEnd();
        }
    }
    classVisitor.visitEnd();
}

From source file:com.googlecode.ddom.weaver.inject.InjectionAdapter.java

License:Apache License

@Override
public void visitEnd() {
    for (InjectableFieldInfo fieldInfo : injectionInfo.getInjectableFields()) {
        MethodVisitor mv = cv.visitMethod(Opcodes.ACC_PRIVATE | Opcodes.ACC_STATIC,
                fieldInfo.getFactoryMethodName(), fieldInfo.getFactoryMethodDesc(), null, new String[0]);
        if (mv != null) {
            fieldInfo.getInjector().generateFactoryMethodCode(mv);
        }//  w w  w.  j  a  v a 2  s .  c o  m
    }
    if (injectionInfo.hasInjectableInstanceFields()) {
        MethodVisitor mv = cv.visitMethod(Opcodes.ACC_PRIVATE, "inject$$instance", "()V", null, new String[0]);
        if (mv != null) {
            mv.visitCode();
            Label l0 = new Label();
            mv.visitLabel(l0);
            for (InjectableFieldInfo fieldInfo : injectionInfo.getInjectableFields()) {
                if (!fieldInfo.isStatic()) {
                    mv.visitVarInsn(Opcodes.ALOAD, 0);
                    mv.visitMethodInsn(Opcodes.INVOKESTATIC, className, fieldInfo.getFactoryMethodName(),
                            fieldInfo.getFactoryMethodDesc());
                    mv.visitFieldInsn(Opcodes.PUTFIELD, className, fieldInfo.getFieldName(),
                            fieldInfo.getFieldDesc());
                }
            }
            mv.visitInsn(Opcodes.RETURN);
            Label l1 = new Label();
            mv.visitLabel(l1);
            mv.visitLocalVariable("this", "L" + className + ";", null, l0, l1, 0);
            mv.visitMaxs(2, 1);
            mv.visitEnd();
        }
    }
    if (injectionInfo.hasInjectableClassFields()) {
        MethodVisitor mv = cv.visitMethod(Opcodes.ACC_PRIVATE | Opcodes.ACC_STATIC,
                hasClassInitializer ? "inject$$class" : "<clinit>", "()V", null, new String[0]);
        if (mv != null) {
            mv.visitCode();
            for (InjectableFieldInfo fieldInfo : injectionInfo.getInjectableFields()) {
                if (fieldInfo.isStatic()) {
                    mv.visitMethodInsn(Opcodes.INVOKESTATIC, className, fieldInfo.getFactoryMethodName(),
                            fieldInfo.getFactoryMethodDesc());
                    mv.visitFieldInsn(Opcodes.PUTSTATIC, className, fieldInfo.getFieldName(),
                            fieldInfo.getFieldDesc());
                }
            }
            mv.visitInsn(Opcodes.RETURN);
            mv.visitMaxs(1, 0);
            mv.visitEnd();
        }
    }
    super.visitEnd();
}

From source file:com.khubla.jvmbasic.jvmbasicc.JVMBasicCompiler.java

License:Open Source License

/**
 * generate init./*ww w.ja v  a  2 s .c o  m*/
 * <p>
 * This inits the class members and assigns class members, such as the ExecutionContext.
 * </p>
 * <p>
 * <code>
 * public ExecutionContext executionContext = new ExecutionContext();
 * </code>
 * </p>
 */
protected void generateInit(String className, ClassWriter classWriter) throws Exception {
    try {
        final MethodVisitor methodVisitor = classWriter.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null,
                null);
        methodVisitor.visitCode();
        /*
         * call init()
         */
        final Label l0 = new Label();
        methodVisitor.visitLabel(l0);
        methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
        methodVisitor.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
        /*
         * create a new execution context and assign it
         */
        final Label l1 = new Label();
        methodVisitor.visitLabel(l1);
        methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
        methodVisitor.visitTypeInsn(Opcodes.NEW, RTLHelper.JASIC_RUNTIME_EXECUTIONCONTEXT);
        methodVisitor.visitInsn(Opcodes.DUP);
        methodVisitor.visitMethodInsn(Opcodes.INVOKESPECIAL, RTLHelper.JASIC_RUNTIME_EXECUTIONCONTEXT, "<init>",
                "()V");
        methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, className, RTLHelper.EXECUTIONCONTEXT_NAME,
                RTLHelper.JASIC_RUNTIME_EXECUTIONCONTEXT_TYPE);
        /*
         * return
         */
        final Label l2 = new Label();
        methodVisitor.visitLabel(l2);
        methodVisitor.visitLineNumber(8, l2);
        methodVisitor.visitInsn(Opcodes.RETURN);
        /*
         * declare variables
         */
        final Label l3 = new Label();
        methodVisitor.visitLabel(l3);
        methodVisitor.visitLocalVariable("this", "L" + className + ";", null, l0, l3, 0);
        methodVisitor.visitMaxs(3, 1);
        methodVisitor.visitEnd();
    } catch (final Exception e) {
        throw new Exception("Exception in generateInit", e);
    }
}

From source file:com.khubla.jvmbasic.jvmbasicc.JVMBasicCompiler.java

License:Open Source License

/**
 * generate void main(String[])//from ww w. j  a v  a2 s . c  om
 * <p>
 * <code>
 * public static void main(String[] args) {
 *   ExampleProgram exampleProgram = new ExampleProgram();
 *  try {
 *       exampleProgram.inputStream = System.in;
 *       exampleProgram.outputStream = System.out;
 *       exampleProgram.program();
 *   } catch (Exception e) {
 *       e.printStackTrace();
 *    }
 *  }
 * </code>
 * </p>
 */
protected void generateMain(String classname, ClassWriter classWriter) throws Exception {
    try {
        /*
         * make method
         */
        final MethodVisitor methodVisitor = classWriter.visitMethod(Opcodes.ACC_PUBLIC + Opcodes.ACC_STATIC,
                "main", "([Ljava/lang/String;)V", null, null);
        methodVisitor.visitCode();
        final Label l0 = new Label();
        final Label l1 = new Label();
        final Label l2 = new Label();
        methodVisitor.visitTryCatchBlock(l0, l1, l2, "java/lang/Exception");
        final Label l3 = new Label();
        methodVisitor.visitLabel(l3);
        /*
         * declare a local instance of the class in the void() main, store as variable 1.
         */
        methodVisitor.visitTypeInsn(Opcodes.NEW, classname);
        methodVisitor.visitInsn(Opcodes.DUP);
        methodVisitor.visitMethodInsn(Opcodes.INVOKESPECIAL, classname, "<init>", "()V");
        methodVisitor.visitVarInsn(Opcodes.ASTORE, 1);
        /*
         * assign the input stream
         */
        methodVisitor.visitVarInsn(Opcodes.ALOAD, 1);
        methodVisitor.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/System", "in", "Ljava/io/InputStream;");
        methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, classname, "inputStream", "Ljava/io/InputStream;");
        /*
         * assign the output stream
         */
        methodVisitor.visitVarInsn(Opcodes.ALOAD, 1);
        methodVisitor.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
        methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, classname, "outputStream", "Ljava/io/PrintStream;");
        /*
         * load the class instance from variable 1 and call "program"
         */
        methodVisitor.visitLabel(l0);
        methodVisitor.visitVarInsn(Opcodes.ALOAD, 1);
        methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, classname, "program", "()V");
        methodVisitor.visitLabel(l1);
        final Label l4 = new Label();
        methodVisitor.visitJumpInsn(Opcodes.GOTO, l4);
        methodVisitor.visitLabel(l2);
        methodVisitor.visitFrame(Opcodes.F_FULL, 2, new Object[] { "[Ljava/lang/String;", classname }, 1,
                new Object[] { "java/lang/Exception" });
        methodVisitor.visitVarInsn(Opcodes.ASTORE, 2);
        final Label l5 = new Label();
        methodVisitor.visitLabel(l5);
        methodVisitor.visitLineNumber(21, l5);
        methodVisitor.visitVarInsn(Opcodes.ALOAD, 2);
        methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Exception", "printStackTrace", "()V");
        /*
         * return
         */
        methodVisitor.visitLabel(l4);
        methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        methodVisitor.visitInsn(Opcodes.RETURN);
        /*
         * declare the parameters
         */
        final Label l6 = new Label();
        methodVisitor.visitLabel(l6);
        methodVisitor.visitLocalVariable("args", "[Ljava/lang/String;", null, l3, l6, 0);
        methodVisitor.visitLocalVariable("exampleProgram", "L" + classname + ";", null, l0, l6, 1);
        methodVisitor.visitLocalVariable("e", "Ljava/lang/Exception;", null, l5, l4, 2);
        /*
         * done
         */
        methodVisitor.visitMaxs(2, 3);
        methodVisitor.visitEnd();
    } catch (final Exception e) {
        throw new Exception("Exception in generateMain", e);
    }
}