Example usage for org.objectweb.asm MethodVisitor visitJumpInsn

List of usage examples for org.objectweb.asm MethodVisitor visitJumpInsn

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Introduction

In this page you can find the example usage for org.objectweb.asm MethodVisitor visitJumpInsn.

Prototype

public void visitJumpInsn(final int opcode, final Label label)

Source Link

Document

Visits a jump instruction.

Usage

From source file:org.moe.natj.processor.cxx.BCGen.java

License:Apache License

/**
 * Generates code which pops the top CxxObject on the stack and replaces it with its _cxx_rt_peer.
 *
 * @param mv        Method visitor//from  w w w.j  a  v a2  s  .  co  m
 * @param checkNull Handle null object case
 */
public static void swapCxxObjectWithItsPeer(MethodVisitor mv, final boolean checkNull) {
    final Label then;
    final Label join;
    if (checkNull) {
        then = new Label();
        join = new Label();

        // if
        mv.visitInsn(DUP);
        mv.visitJumpInsn(IFNONNULL, then);

        // else
        mv.visitInsn(POP);
        mv.visitInsn(LCONST_0);
        mv.visitJumpInsn(GOTO, join);

        // then
        mv.visitLabel(then);
    } else {
        join = null;
    }

    mv.visitTypeInsn(CHECKCAST, CxxSupport.CXX_OBJECT_ITF.getInternalName());
    mv.visitMethodInsn(INVOKEINTERFACE, CxxSupport.CXX_OBJECT_ITF.getInternalName(), "_cxx_rt_peer",
            Type.getMethodDescriptor(Type.LONG_TYPE), true);

    if (checkNull) {
        // join
        mv.visitLabel(join);
    }
}

From source file:org.moe.natj.processor.cxx.BCGen.java

License:Apache License

private static void CxxRuntime_getOrConstruct_dynamicType(MethodVisitor mv, CxxType type,
        CxxUtils.LocalManager localManager, CxxClassInfo itf, ITypeResolverPlugin plugin) {
    final int nextIndex = localManager.getNextIndex();
    final CxxUtils.Local peer = localManager.getNext("__cxx_GOC" + nextIndex, Type.LONG_TYPE, 2);
    final CxxUtils.Local rslt = localManager.getNext("__cxx_GOC" + nextIndex + "_R", itf.mapperType, 1);
    final Label endL = new Label();

    // Local variable start labels
    mv.visitLabel(peer.start);// ww  w  .j  av  a 2 s  . com
    mv.visitLabel(rslt.start);

    // Save peer
    mv.visitVarInsn(LSTORE, peer.index);

    // CxxRuntime.get(peer)
    mv.visitVarInsn(LLOAD, peer.index);
    mv.visitMethodInsn(INVOKESTATIC, CxxSupport.CXX_RUNTIME.getInternalName(), "get",
            Type.getMethodDescriptor(CxxSupport.CXX_OBJECT_ITF, Type.LONG_TYPE), false);
    mv.visitInsn(DUP);
    mv.visitTypeInsn(INSTANCEOF, itf.mapperType.getInternalName());
    mv.visitJumpInsn(IFNE, endL);

    // Construct
    mv.visitInsn(POP);
    mv.visitVarInsn(LLOAD, peer.index);
    mv.visitVarInsn(LLOAD, peer.index);
    final String getterMethod;
    if (type.isConstCxxObjectKind()) {
        getterMethod = "getConstClassForType";
    } else {
        getterMethod = "getClassForType";
    }
    mv.visitMethodInsn(INVOKESTATIC, plugin.getImplementingClass() + "$__cxx_TypeRes", getterMethod,
            Type.getMethodDescriptor(Type.getObjectType("java/lang/Class"), Type.LONG_TYPE), false);
    mv.visitMethodInsn(INVOKESTATIC, CxxSupport.CXX_RUNTIME.getInternalName(), "construct",
            Type.getMethodDescriptor(CxxSupport.CXX_OBJECT_ITF, Type.LONG_TYPE,
                    Type.getObjectType("java/lang/Class")),
            false);

    // Join
    mv.visitLabel(endL);
    mv.visitTypeInsn(CHECKCAST, itf.mapperType.getInternalName());
    mv.visitVarInsn(ASTORE, rslt.index);
    mv.visitVarInsn(ALOAD, rslt.index);

    // Local variable end labels
    mv.visitLabel(peer.end);
    mv.visitLabel(rslt.end);
}

From source file:org.moe.natj.processor.cxx.BCGen.java

License:Apache License

private static void CxxRuntime_getOrConstruct_binding(MethodVisitor mv, CxxUtils.LocalManager localManager,
        CxxClassInfo itf, Type implClass, boolean isConst) {
    final int nextIndex = localManager.getNextIndex();
    final CxxUtils.Local peer = localManager.getNext("__cxx_GOC" + nextIndex, Type.LONG_TYPE, 2);
    final CxxUtils.Local rslt = localManager.getNext("__cxx_GOC" + nextIndex + "_R", itf.mapperType, 1);
    final Label endL = new Label();
    final Label constructL = new Label();

    // Local variable start labels
    mv.visitLabel(peer.start);//from  www  . ja  v  a 2s.  com
    mv.visitLabel(rslt.start);

    // Save peer
    mv.visitVarInsn(LSTORE, peer.index);

    // CxxRuntime.get(peer)
    mv.visitVarInsn(LLOAD, peer.index);
    mv.visitMethodInsn(INVOKESTATIC, CxxSupport.CXX_RUNTIME.getInternalName(), "get",
            Type.getMethodDescriptor(CxxSupport.CXX_OBJECT_ITF, Type.LONG_TYPE), false);
    mv.visitInsn(DUP);
    mv.visitTypeInsn(INSTANCEOF, itf.mapperType.getInternalName());
    mv.visitJumpInsn(IFEQ, constructL);

    // Check const-nes
    mv.visitInsn(DUP);
    mv.visitTypeInsn(INSTANCEOF, CxxSupport.CXX_CONST_IMPL_ITF.getInternalName());
    mv.visitJumpInsn(isConst ? IFEQ : IFNE, constructL);

    // Store
    mv.visitTypeInsn(CHECKCAST, itf.mapperType.getInternalName());
    mv.visitVarInsn(ASTORE, rslt.index);
    mv.visitJumpInsn(GOTO, endL);

    // Construct
    mv.visitLabel(constructL);
    mv.visitInsn(POP);
    mv.visitTypeInsn(NEW, implClass.getInternalName());
    mv.visitInsn(DUP);
    mv.visitVarInsn(LLOAD, peer.index);
    mv.visitMethodInsn(INVOKESPECIAL, implClass.getInternalName(), "<init>", "(J)V", false);
    mv.visitVarInsn(ASTORE, rslt.index);

    // Join
    mv.visitLabel(endL);
    mv.visitVarInsn(ALOAD, rslt.index);

    // Local variable end labels
    mv.visitLabel(peer.end);
    mv.visitLabel(rslt.end);
}

From source file:org.nuclos.server.customcode.codegenerator.ClassDebugAdapter.java

License:Open Source License

private void insertDebugResolveMethod() {
    /*/*from   w w  w .  j a  v  a2  s  . c o m*/
      private String __resolve(String methodAndIndex) {
         if(methodAndIndex.equals("method1"))
      return "var1";
         if(methodAndIndex.equals("method2"))
      return "var2";
         [ ... ]
         if(methodAndIndex.equals("methodX"))
      return "varX";
         return "-";
      }
     */
    MethodVisitor mv = cv.visitMethod(ACC_PRIVATE + ACC_STATIC, "__resolve",
            "(Ljava/lang/String;)Ljava/lang/String;", null, null);
    mv.visitCode();
    Label l0 = new Label();
    mv.visitLabel(l0);
    for (String mapKey : varLookup.keySet()) {
        mv.visitVarInsn(ALOAD, 0);
        mv.visitLdcInsn(mapKey);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "equals", "(Ljava/lang/Object;)Z");
        Label l1 = new Label();
        mv.visitJumpInsn(IFEQ, l1);
        Label l2 = new Label();
        mv.visitLabel(l2);
        mv.visitLdcInsn(varLookup.get(mapKey));
        mv.visitInsn(ARETURN);
        mv.visitLabel(l1);
        mv.visitFrame(F_SAME, 0, null, 0, null);
    }
    mv.visitLdcInsn("-");
    mv.visitInsn(ARETURN);
    mv.visitMaxs(2, 2);
    mv.visitEnd();
}

From source file:org.openquark.cal.internal.javamodel.AsmJavaBytecodeGenerator.java

License:Open Source License

/**
 * Add the <clinit> method. This initializes the static fields that have initializers.
 * @param classRep// ww  w .j av a  2s.c om
 * @param cv
 * @param initializeForAsserts
 * @throws JavaGenerationException
 */
private static void encodeClassInitializer(JavaClassRep classRep, ClassVisitor cv, boolean initializeForAsserts)
        throws JavaGenerationException {

    // Add initializers for the statically-initialized fields.
    final int nFields = classRep.getNFieldDeclarations();

    if (!classRep.hasInitializedStaticField() && !initializeForAsserts) {
        //we don't need to bother adding a static initializer if there are no static fields to initialize.
        //note that javac also has this optimization.
        return;
    }

    MethodVisitor mv = cv.visitMethod(Opcodes.ACC_STATIC, "<clinit>", "()V", null, null);

    // Start the method's code.
    mv.visitCode();

    final JavaTypeName classRepTypeName = classRep.getClassName();

    /*
     * If this class contains assert statements we need to initialize the static final synthetic boolean field
     * '$assertionsDisabled'.
     * This is done by loading the Class constant for the top level class. The method 'desiredAssertionStatus()'
     * is then invoked on this Class object and the returned value is used to initialize $assertionsDisabled. 
     */
    if (initializeForAsserts) {
        // Get the fully-qualified internal class  name.    
        final String className = classRepTypeName.getJVMInternalName();

        // Get the top level class name.
        String topLevelClassName = getTopLevelClassJVMInternalName(className);

        // Load the Class constant for the top level class
        mv.visitLdcInsn(Type.getType("L" + topLevelClassName + ";"));

        // Now that we have the Class constant for the top level class we invoke the method
        // desiredAssertionStatus on it and use the resulting value to initialize the static field $assertionsDisabled in this class.
        mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "desiredAssertionStatus", "()Z");
        Label l0 = new Label();
        mv.visitJumpInsn(Opcodes.IFNE, l0);
        mv.visitInsn(Opcodes.ICONST_1);
        Label l1 = new Label();
        mv.visitJumpInsn(Opcodes.GOTO, l1);
        mv.visitLabel(l0);
        mv.visitInsn(Opcodes.ICONST_0);
        mv.visitLabel(l1);
        mv.visitFieldInsn(Opcodes.PUTSTATIC, className, "$assertionsDisabled", "Z");
    }

    for (int i = 0; i < nFields; ++i) {

        JavaFieldDeclaration fieldDecl = classRep.getFieldDeclaration(i);
        JavaExpression initializer = fieldDecl.getInitializer();

        if (initializer != null && Modifier.isStatic(fieldDecl.getModifiers())) {

            GenerationContext context = new GenerationContext(new HashMap<String, JavaTypeName>(),
                    new HashMap<String, Integer>(), 0, mv, classRepTypeName);

            //evaluate the initializer
            encodeExpr(initializer, context);

            //do the assignment
            mv.visitFieldInsn(Opcodes.PUTSTATIC, classRep.getClassName().getJVMInternalName(),
                    fieldDecl.getFieldName(), fieldDecl.getFieldType().getJVMDescriptor());
        }
    }

    // return.
    mv.visitInsn(Opcodes.RETURN);

    //mark the end of the method with a call to visitMaxs
    mv.visitMaxs(0, 0);

    // End the method.
    mv.visitEnd();
}

From source file:org.openquark.cal.internal.javamodel.AsmJavaBytecodeGenerator.java

License:Open Source License

private static boolean encodeIfThenElseStatement(JavaStatement.IfThenElseStatement iteStatement,
        GenerationContext context) throws JavaGenerationException {

    MethodVisitor mv = context.getMethodVisitor();

    JavaExpression conditionExpr = iteStatement.getCondition();
    JavaStatement thenStatement = iteStatement.getThenStatement();
    JavaStatement elseStatement = iteStatement.getElseStatement();

    if (conditionExpr instanceof JavaExpression.OperatorExpression) {

        //generate more efficient code in the case of if (boolean-valued-operator)...

        //This case exists to handle the special case where an operator occurs as the child of an if-then-else (or ternary operator)
        //conditional. For example, in the situation:
        ///*from w  w w  .j a v a2  s . com*/
        //if (x != null) {...} else {...}
        // 
        // we do not want to evaluate x != null to a boolean value, push that value on the stack,
        // and then test it prior to selecting the correct branch. Rather, we can combine the evaluation
        // and jump operations into a single step.

        JavaExpression.OperatorExpression operatorExpr = (JavaExpression.OperatorExpression) conditionExpr;
        JavaOperator operator = operatorExpr.getJavaOperator();

        if (operator.isLogicalOp() || operator.isRelationalOp()) {

            Label trueContinuation = new Label();
            context.addStatementJumpLabel(trueContinuation);

            Label falseContinuation = new Label();
            context.addStatementJumpLabel(falseContinuation);

            encodeBooleanValuedOperatorHelper(operatorExpr, context, trueContinuation, falseContinuation);
            return encodeThenStatementElseStatement(trueContinuation, falseContinuation, thenStatement,
                    elseStatement, context);
        }

        throw new JavaGenerationException(
                "Unrecognized boolean-valued conditional operator " + operator.getSymbol() + ".");
    }

    //encode the condition. It will be boolean valued.
    encodeExpr(iteStatement.getCondition(), context);

    //if false, jump to falseContinuation
    Label falseContinuation = new Label();
    mv.visitJumpInsn(Opcodes.IFEQ, falseContinuation);

    return encodeThenStatementElseStatement(null, falseContinuation, thenStatement, elseStatement, context);
}

From source file:org.openquark.cal.internal.javamodel.AsmJavaBytecodeGenerator.java

License:Open Source License

private static boolean encodeThenStatementElseStatement(Label trueContinuation, Label falseContinuation,
        JavaStatement thenStatement, JavaStatement elseStatement, GenerationContext context)
        throws JavaGenerationException {

    MethodVisitor mv = context.getMethodVisitor();

    if (trueContinuation != null) {
        mv.visitLabel(trueContinuation);
    }/*from  w ww. j  a  v  a  2  s. c  o m*/

    //in general the "then" part will have its own inner scope, but we optimize this out in the case of ExpressionStatements which
    //can't introduce new variables.
    GenerationContext thenContext = (thenStatement instanceof JavaStatement.ExpressionStatement) ? context
            : new GenerationContext(context);

    boolean thenIsTerminating = encodeStatement(thenStatement, thenContext);
    context.addJumpReturnLabelInfo(thenContext);

    if (elseStatement.emptyStatement()) {
        //don't bother to encode the goto skipping over the else part if there is not else part.

        mv.visitLabel(falseContinuation);

        //the if-then-else is not terminating, because the else part, which is just {}, is not terminating
        return false;
    }

    Label label2 = null;
    if (!thenIsTerminating) {
        label2 = new Label();
        context.addStatementJumpLabel(label2);

        mv.visitJumpInsn(Opcodes.GOTO, label2);
    }

    mv.visitLabel(falseContinuation);

    //in general the "else" part will have its own inner scope, but we optimize this out in the case of ExpressionStatements which
    //can't introduce new variables.
    GenerationContext elseContext = (elseStatement instanceof JavaStatement.ExpressionStatement) ? context
            : new GenerationContext(context);
    boolean elseIsTerminating = encodeStatement(elseStatement, elseContext);
    context.addJumpReturnLabelInfo(elseContext);

    if (!thenIsTerminating) {
        mv.visitLabel(label2);
    }

    return thenIsTerminating && elseIsTerminating;
}

From source file:org.openquark.cal.internal.javamodel.AsmJavaBytecodeGenerator.java

License:Open Source License

private static boolean encodeTryCatchStatement(JavaStatement.Block block, GenerationContext context)
        throws JavaGenerationException {

    MethodVisitor mv = context.getMethodVisitor();

    List<JavaExceptionHandler> exceptionHandlers = block.getExceptionHandlers();

    if (exceptionHandlers.isEmpty()) {
        throw new IllegalStateException();
    }//from  w  w w .  j av a  2 s  .c o  m

    // Spawn a child context for the try block.
    GenerationContext tryBlockContext = new GenerationContext(context);

    boolean isTerminating = false; // starts out false (for the case with no statements..)

    Label tryStartLabel = new Label();
    mv.visitLabel(tryStartLabel);

    // Append the instructions comprising the block's component statements.
    int nStatements = block.getNBlockStatements();
    for (int i = 0; i < nStatements; i++) {
        JavaStatement blockStatement = block.getNthBlockStatement(i);

        // skip comments.
        if (blockStatement instanceof Comment) {
            continue;
        }

        // is terminating if the last statement is terminating. 
        isTerminating = encodeStatement(blockStatement, tryBlockContext);
        context.addJumpReturnLabelInfo(tryBlockContext);
    }

    // Add an instruction to jump to after the exception handlers, if the statement block isn't terminating.
    Label tryCatchEndLabel = new Label();
    context.addStatementJumpLabel(tryCatchEndLabel);
    if (!isTerminating) {
        mv.visitJumpInsn(Opcodes.GOTO, tryCatchEndLabel);
    }

    Label tryEndLabel = new Label();
    mv.visitLabel(tryEndLabel);

    // Add exception handlers as necessary.      

    // Now set handlers to handle any exceptions.
    for (int i = 0, nExceptionHandlers = exceptionHandlers.size(); i < nExceptionHandlers; ++i) {

        JavaExceptionHandler eh = exceptionHandlers.get(i);

        JavaTypeName exceptionType = JavaTypeName.make(eh.getExceptionClass()); // exception class is a non-array reference type.  

        //encode the start of the catch block.
        Label catchLabel = new Label();
        mv.visitLabel(catchLabel);

        // Create a child context for the catch block.
        GenerationContext catchContext = new GenerationContext(context);

        // The thrown exception object will be the only item on the stack.  
        // Store it into a new local variable.
        String exceptionVarName = eh.getExceptionVarName();
        int exceptionVarIndex = catchContext.addLocalVar(exceptionVarName, exceptionType);
        mv.visitVarInsn(Opcodes.ASTORE, exceptionVarIndex);

        boolean catchIsTerminating = encodeStatement(eh.getHandlerCode(), catchContext);
        context.addJumpReturnLabelInfo(catchContext);

        if (!catchIsTerminating) {
            mv.visitJumpInsn(Opcodes.GOTO, tryCatchEndLabel);
        }

        // In the end, we're only terminating if all the catch blocks are terminating.
        isTerminating &= catchIsTerminating;

        //encode the try/catch block. This can be done in any order, any time after all labels passed as arguments have been visited,
        //  between visitCode() and visitMaxs().
        encodeTryCatchBlock(tryStartLabel, tryEndLabel, catchLabel, exceptionType, tryBlockContext);
    }

    //mark the end of the whole try/catch code
    mv.visitLabel(tryCatchEndLabel);

    return isTerminating;
}

From source file:org.openquark.cal.internal.javamodel.AsmJavaBytecodeGenerator.java

License:Open Source License

private static boolean encodeUnconditionalLoop(JavaStatement.UnconditionalLoop ul, GenerationContext context)
        throws JavaGenerationException {

    //implemented as:
    //label label1:
    //{ body statements}
    //goto label1

    MethodVisitor mv = context.getMethodVisitor();
    Label label1 = new Label();
    mv.visitLabel(label1);/*w  w w.  ja va2s .  co  m*/

    context.addStatementJumpLabel(ul.getLabel(), label1);

    //the body defines a new scope.
    GenerationContext bodyContext = new GenerationContext(context);

    boolean bodyIsTerminating = encodeStatement(ul.getBody(), bodyContext);
    context.addJumpReturnLabelInfo(bodyContext);

    if (!bodyIsTerminating) {
        mv.visitJumpInsn(Opcodes.GOTO, label1);
    }

    return true;
}

From source file:org.openquark.cal.internal.javamodel.AsmJavaBytecodeGenerator.java

License:Open Source License

/**
 * Encode a method invocation that is wrapped in a synchronized block.
 *   See Sun bug id #4414101 for a discussion of this generated code.
 * //from   ww  w  . j  a  v  a 2  s .c o m
 * @param smi - the SynchronizedMethodInvocation object.
 * @param context - the context of the code generation.
 * @return - true if the SynchronizedMethodInvocation is terminating.
 * @throws JavaGenerationException
 */
private static boolean encodeSynchronizedMethodInvocation(JavaStatement.SynchronizedMethodInvocation smi,
        GenerationContext context) throws JavaGenerationException {

    MethodVisitor mv = context.getMethodVisitor();

    // Get the JavaExpression for the object to synchronize on and generate the bytecode. 
    JavaExpression objectToSynchOn = smi.getSynchronizingObject();
    encodeExpr(objectToSynchOn, context);

    // The object to synchronize on is now on the stack.  Duplicate it, 
    // move one to storage as a local variable, and to MONITORENTER on the other. 
    mv.visitInsn(Opcodes.DUP);

    int mutexIndex = context.addLocalVar("$mutex", JavaTypeName.OBJECT);
    mv.visitVarInsn(Opcodes.ASTORE, mutexIndex);

    mv.visitInsn(Opcodes.MONITORENTER);

    // We need to wrap the method invocation in a try/catch block so 
    // the monitor can be exited properly if the method invocation throws
    // an exception.
    Label tryCatchStart = new Label();
    mv.visitLabel(tryCatchStart);

    // Note: if this is generalized to handle any synchronized statement (for example, a synchronized block), 
    //   then the scope of entries in the exception table here will have to be modified to exclude return instructions.
    //   See encodeTryCatchStatement() for how to do this.
    //   Here, the only statement in the try block is a single expressionStatement, which has no return instructions, 
    //     so we don't have to worry about handling this case.

    // Get the method invocation and generate the corresponding bytecode.
    MethodInvocation methodInvocation = smi.getMethodInvocation();
    encodeExpr(methodInvocation, context);

    // Load the mutex object back onto the stack and do MonitorExit.
    mv.visitVarInsn(Opcodes.ALOAD, mutexIndex);
    mv.visitInsn(Opcodes.MONITOREXIT);

    // Label the end of the try block around the method invocation.
    Label tryEnd = new Label();
    mv.visitLabel(tryEnd);

    // At this point we want to code an instruction to jump past the exception handling
    // code.
    Label tryCatchEnd = new Label();
    mv.visitJumpInsn(Opcodes.GOTO, tryCatchEnd);

    // Label the start of the exception handling code.
    Label catchStart = new Label();
    mv.visitLabel(catchStart);

    // The exception is on the stack.  Store it as a local.
    int exceptionIndex = context.addLocalVar("exception", JavaTypeName.OBJECT);
    mv.visitVarInsn(Opcodes.ASTORE, exceptionIndex);

    // Retrieve the mutex object and do MONITOREXIT.
    mv.visitVarInsn(Opcodes.ALOAD, mutexIndex);
    mv.visitInsn(Opcodes.MONITOREXIT);

    // Label the end of the exception handling code that deals with the monitor.
    Label exceptionMonitorExitEnd = new Label();
    mv.visitLabel(exceptionMonitorExitEnd);

    // Retrieve the exception and throw it.
    mv.visitVarInsn(Opcodes.ALOAD, exceptionIndex);
    mv.visitInsn(Opcodes.ATHROW);

    // Vist the label to mark the end of the try/catch.
    mv.visitLabel(tryCatchEnd);

    // Set up the try/catch block to catch exceptions thrown by the method invocation
    // and handle exiting the monitor.
    mv.visitTryCatchBlock(tryCatchStart, tryEnd, catchStart, null);

    // Set up a try catch block so that if an exception is thrown by trying to exit 
    // the monitor in the case of an exception from the method invocation we will keep trying to 
    // exit the monitor.
    mv.visitTryCatchBlock(catchStart, exceptionMonitorExitEnd, catchStart, null);

    return false;
}