Example usage for org.objectweb.asm Label Label

List of usage examples for org.objectweb.asm Label Label

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Introduction

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

Prototype

public Label()

Source Link

Document

Constructs a new label.

Usage

From source file:com.nginious.http.xsp.expr.LeftFunction.java

License:Apache License

/**
 * Creates bytecode for evaluating this left function. The specified method visitor
 * and type are used for generating bytecode.
 * // w w  w. ja  v a2  s .  co m
 * @param visitor the method visitor
 * @param type the type
 */
void compile(MethodVisitor visitor, Type type) {
    value.compile(visitor, Type.STRING);
    visitor.visitVarInsn(Opcodes.ASTORE, 1);

    Label nullLabel = new Label();
    Label notNullLabel = new Label();

    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitJumpInsn(Opcodes.IFNULL, nullLabel);

    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitLdcInsn(0);
    value2.compile(visitor, Type.INT);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "substring", "(II)Ljava/lang/String;");
    visitor.visitJumpInsn(Opcodes.GOTO, notNullLabel);

    visitor.visitLabel(nullLabel);
    visitor.visitInsn(Opcodes.ACONST_NULL);

    visitor.visitLabel(notNullLabel);
}

From source file:com.nginious.http.xsp.expr.LengthFunction.java

License:Apache License

/**
 * Creates bytecode for evaluating this function. The specified method
 * visitor is used to generate bytecode. The generated bytecode produces
 * a result of the specified type.//from w w  w. jav  a2s.  c o  m
 * 
 * @param visitor the method visitor
 * @param type the type
 */
void compile(MethodVisitor visitor, Type type) {
    value.compile(visitor, Type.STRING);
    visitor.visitVarInsn(Opcodes.ASTORE, 1);

    Label nullLabel = new Label();
    Label notNullLabel = new Label();

    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitJumpInsn(Opcodes.IFNULL, nullLabel);

    visitor.visitVarInsn(Opcodes.ALOAD, 1);
    visitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/String", "length", "()I");
    visitor.visitJumpInsn(Opcodes.GOTO, notNullLabel);

    visitor.visitLabel(nullLabel);
    visitor.visitLdcInsn(0);

    visitor.visitLabel(notNullLabel);
}

From source file:com.nginious.http.xsp.expr.LessEqualsOperator.java

License:Apache License

/**
 * Creates bytecode for evaluating the argument values as integers. The bytecode
 * is generated using the specified method visitor.
 * /*from   w  ww .j  a  va2  s  .  co m*/
 * @param visitor the method visitor
 */
private void compileInt(MethodVisitor visitor) {
    Label labelFalse = new Label();
    Label labelEnd = new Label();

    value2.compile(visitor, Type.INT);
    value1.compile(visitor, Type.INT);

    visitor.visitJumpInsn(Opcodes.IF_ICMPLT, labelFalse);

    // True
    visitor.visitLdcInsn(true);
    visitor.visitJumpInsn(Opcodes.GOTO, labelEnd);

    // False
    visitor.visitLabel(labelFalse);
    visitor.visitLdcInsn(false);

    visitor.visitLabel(labelEnd);
}

From source file:com.nginious.http.xsp.expr.LessEqualsOperator.java

License:Apache License

/**
 * Creates bytecode for evaluating the argument values as doubles. The bytecode
 * is generated using the specified method visitor.
 * //from   ww w .j  ava 2s  .c  om
 * @param visitor the method visitor
 */
private void compileDouble(MethodVisitor visitor) {
    Label labelFalse = new Label();
    Label labelEnd = new Label();

    value2.compile(visitor, Type.DOUBLE);
    value1.compile(visitor, Type.DOUBLE);

    visitor.visitInsn(Opcodes.DCMPL);
    visitor.visitJumpInsn(Opcodes.IFLT, labelFalse);

    // True
    visitor.visitLdcInsn(true);
    visitor.visitJumpInsn(Opcodes.GOTO, labelEnd);

    // False
    visitor.visitLabel(labelFalse);
    visitor.visitLdcInsn(false);

    visitor.visitLabel(labelEnd);
}

From source file:com.nginious.http.xsp.expr.LessOperator.java

License:Apache License

/**
 * Creates bytecode for evaluating the argument values as integers. The bytecode
 * is generated using the specified method visitor.
 * /*from  ww  w  .j ava  2s  . c om*/
 * @param visitor the method visitor
 */
private void compileInt(MethodVisitor visitor) {
    Label labelFalse = new Label();
    Label labelEnd = new Label();

    value2.compile(visitor, Type.INT);
    value1.compile(visitor, Type.INT);

    visitor.visitJumpInsn(Opcodes.IF_ICMPLE, labelFalse);

    // True
    visitor.visitLdcInsn(true);
    visitor.visitJumpInsn(Opcodes.GOTO, labelEnd);

    // False
    visitor.visitLabel(labelFalse);
    visitor.visitLdcInsn(false);

    visitor.visitLabel(labelEnd);
}

From source file:com.nginious.http.xsp.expr.LessOperator.java

License:Apache License

/**
 * Creates bytecode for evaluating the argument values as doubles. The bytecode
 * is generated using the specified method visitor.
 * //from  ww  w . j a v  a 2s. c  o  m
 * @param visitor the method visitor
 */
private void compileDouble(MethodVisitor visitor) {
    Label labelFalse = new Label();
    Label labelEnd = new Label();

    value2.compile(visitor, Type.DOUBLE);
    value1.compile(visitor, Type.DOUBLE);

    visitor.visitInsn(Opcodes.DCMPL);
    visitor.visitJumpInsn(Opcodes.IFLE, labelFalse);

    // True
    visitor.visitLdcInsn(true);
    visitor.visitJumpInsn(Opcodes.GOTO, labelEnd);

    // False
    visitor.visitLabel(labelFalse);
    visitor.visitLdcInsn(false);

    visitor.visitLabel(labelEnd);
}

From source file:com.nginious.http.xsp.expr.MoreEqualsOperator.java

License:Apache License

/**
 * Creates bytecode for evaluating the argument values as integers. The bytecode
 * is generated using the specified method visitor.
 * /*  w ww  .  j  av a  2 s  .c  om*/
 * @param visitor the method visitor
 */
private void compileInt(MethodVisitor visitor) {
    Label labelFalse = new Label();
    Label labelEnd = new Label();

    value1.compile(visitor, Type.INT);
    value2.compile(visitor, Type.INT);

    visitor.visitJumpInsn(Opcodes.IF_ICMPLT, labelFalse);

    // True
    visitor.visitLdcInsn(true);
    visitor.visitJumpInsn(Opcodes.GOTO, labelEnd);

    // False
    visitor.visitLabel(labelFalse);
    visitor.visitLdcInsn(false);

    visitor.visitLabel(labelEnd);
}

From source file:com.nginious.http.xsp.expr.MoreEqualsOperator.java

License:Apache License

/**
 * Creates bytecode for evaluating the argument values as doubles. The bytecode
 * is generated using the specified method visitor.
 * //from w  ww .j  a  v  a 2s . co m
 * @param visitor the method visitor
 */
private void compileDouble(MethodVisitor visitor) {
    Label labelFalse = new Label();
    Label labelEnd = new Label();

    value1.compile(visitor, Type.DOUBLE);
    value2.compile(visitor, Type.DOUBLE);

    visitor.visitInsn(Opcodes.DCMPL);
    visitor.visitJumpInsn(Opcodes.IFLT, labelFalse);

    // True
    visitor.visitLdcInsn(true);
    visitor.visitJumpInsn(Opcodes.GOTO, labelEnd);

    // False
    visitor.visitLabel(labelFalse);
    visitor.visitLdcInsn(false);

    visitor.visitLabel(labelEnd);
}

From source file:com.nginious.http.xsp.expr.MoreOperator.java

License:Apache License

/**
 * Creates bytecode for evaluating the argument values as integers. The bytecode
 * is generated using the specified method visitor.
 * //w w  w.  java 2  s.c  o  m
 * @param visitor the method visitor
 */
private void compileInt(MethodVisitor visitor) {
    Label labelFalse = new Label();
    Label labelEnd = new Label();

    value1.compile(visitor, Type.INT);
    value2.compile(visitor, Type.INT);

    visitor.visitJumpInsn(Opcodes.IF_ICMPLE, labelFalse);

    // True
    visitor.visitLdcInsn(true);
    visitor.visitJumpInsn(Opcodes.GOTO, labelEnd);

    // False
    visitor.visitLabel(labelFalse);
    visitor.visitLdcInsn(false);

    visitor.visitLabel(labelEnd);
}

From source file:com.nginious.http.xsp.expr.MoreOperator.java

License:Apache License

/**
 * Creates bytecode for evaluating the argument values as doubles. The bytecode
 * is generated using the specified method visitor.
 * /*from  w ww .ja  v a2  s .c o  m*/
 * @param visitor the method visitor
 */
private void compileDouble(MethodVisitor visitor) {
    Label labelFalse = new Label();
    Label labelEnd = new Label();

    value1.compile(visitor, Type.DOUBLE);
    value2.compile(visitor, Type.DOUBLE);

    visitor.visitInsn(Opcodes.DCMPL);
    visitor.visitJumpInsn(Opcodes.IFLE, labelFalse);

    // True
    visitor.visitLdcInsn(true);
    visitor.visitJumpInsn(Opcodes.GOTO, labelEnd);

    // False
    visitor.visitLabel(labelFalse);
    visitor.visitLdcInsn(false);

    visitor.visitLabel(labelEnd);
}