org.jacoco.core.internal.flow.MethodProbesVisitor.java Source code

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Here is the source code for org.jacoco.core.internal.flow.MethodProbesVisitor.java

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/*******************************************************************************
 * Copyright (c) 2009, 2013 Mountainminds GmbH & Co. KG and Contributors
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Marc R. Hoffmann - initial API and implementation
 *    
 *******************************************************************************/
package org.jacoco.core.internal.flow;

import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

/**
 * A {@link MethodVisitor} with additional methods to get probe insertion
 * information.
 */
public abstract class MethodProbesVisitor extends MethodVisitor {

    /**
     * New visitor instance without delegate visitor.
     */
    public MethodProbesVisitor() {
        this(null);
    }

    /**
     * New visitor instance that delegates to the given visitor.
     * 
     * @param mv
     *            optional next visitor in chain
     */
    public MethodProbesVisitor(final MethodVisitor mv) {
        super(Opcodes.ASM4, mv);
    }

    /**
     * Visits an unconditional probe that should be inserted at the current
     * position.
     * 
     * @param probeId
     *            id of the probe to insert
     */
    public abstract void visitProbe(int probeId);

    /**
     * Visits a jump instruction. A probe with the given id should be inserted
     * in a way that it is executed only when the jump to the given label is
     * executed.
     * 
     * @param opcode
     *            the opcode of the type instruction to be visited. This opcode
     *            is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ,
     *            IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE,
     *            IF_ACMPEQ, IF_ACMPNE, GOTO, IFNULL or IFNONNULL.
     * @param label
     *            the operand of the instruction to be visited. This operand is
     *            a label that designates the instruction to which the jump
     *            instruction may jump.
     * @param probeId
     *            id of the probe
     * @see MethodVisitor#visitJumpInsn(int, Label)
     */
    public abstract void visitJumpInsnWithProbe(int opcode, Label label, int probeId);

    /**
     * Visits a zero operand instruction with a probe. This event is used only
     * for instructions that terminate the method. Therefore the probe must be
     * inserted before the actual instruction.
     * 
     * @param opcode
     *            the opcode of the instruction to be visited. This opcode is
     *            either IRETURN, LRETURN, FRETURN, DRETURN, ARETURN, RETURN or
     *            ATHROW.
     * @param probeId
     *            id of the probe
     * @see MethodVisitor#visitInsn(int)
     */
    public abstract void visitInsnWithProbe(int opcode, int probeId);

    /**
     * Visits a TABLESWITCH instruction with optional probes for each target
     * label. Implementations can be optimized based on the fact that the same
     * target labels will always have the same probe id within a call to this
     * method. The probe id for each label can be obtained with
     * {@link LabelInfo#getProbeId(Label)}.
     * 
     * @param min
     *            the minimum key value.
     * @param max
     *            the maximum key value.
     * @param dflt
     *            beginning of the default handler block.
     * @param labels
     *            beginnings of the handler blocks. <code>labels[i]</code> is
     *            the beginning of the handler block for the
     *            <code>min + i</code> key.
     * @see MethodVisitor#visitTableSwitchInsn(int, int, Label, Label[])
     */
    public abstract void visitTableSwitchInsnWithProbes(int min, int max, Label dflt, Label[] labels);

    /**
     * Visits a LOOKUPSWITCH instruction with optional probes for each target
     * label. Implementations can be optimized based on the fact that the same
     * target labels will always have the same probe id within a call to this
     * method. The probe id for each label can be obtained with
     * {@link LabelInfo#getProbeId(Label)}.
     * 
     * @param dflt
     *            beginning of the default handler block.
     * @param keys
     *            the values of the keys.
     * @param labels
     *            beginnings of the handler blocks. <code>labels[i]</code> is
     *            the beginning of the handler block for the
     *            <code>keys[i]</code> key.
     * @see MethodVisitor#visitLookupSwitchInsn(Label, int[], Label[])
     */
    public abstract void visitLookupSwitchInsnWithProbes(Label dflt, int[] keys, Label[] labels);

}