LabelInfo.java
/*******************************************************************************
* Copyright (c) 2009, 2024 Mountainminds GmbH & Co. KG and Contributors
* This program and the accompanying materials are made available under
* the terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* Marc R. Hoffmann - initial API and implementation
*
*******************************************************************************/
package org.jacoco.core.internal.flow;
import org.jacoco.core.internal.analysis.Instruction;
import org.objectweb.asm.Label;
/**
* Data container that is attached to {@link Label#info} objects to store flow
* and instrumentation specific information. The information is only valid
* locally in specific contexts.
*/
public final class LabelInfo {
/**
* Reserved ID for "no probe".
*/
public static final int NO_PROBE = -1;
private boolean target = false;
private boolean multiTarget = false;
private boolean successor = false;
private boolean methodInvocationLine = false;
private boolean done = false;
private int probeid = NO_PROBE;
private Label intermediate = null;
private Instruction instruction = null;
// instances are only created within this class
private LabelInfo() {
}
/**
* Defines that the given label is a jump target.
*
* @param label
* label to define
*/
public static void setTarget(final Label label) {
final LabelInfo info = create(label);
if (info.target || info.successor) {
info.multiTarget = true;
} else {
info.target = true;
}
}
/**
* Defines that the given label is the possible successor of the previous
* instruction in the method.
*
* @param label
* label to define
*/
public static void setSuccessor(final Label label) {
final LabelInfo info = create(label);
info.successor = true;
if (info.target) {
info.multiTarget = true;
}
}
/**
* Checks whether multiple control paths lead to a label. Control flow path
* to a certain label are: jump targets, exception handlers and normal
* control flow from its predecessor instruction (unless this is an
* unconditional jump or method exit).
*
* @param label
* label to check
* @return <code>true</code> if the given multiple control paths lead to the
* given label
*/
public static boolean isMultiTarget(final Label label) {
final LabelInfo info = get(label);
return info == null ? false : info.multiTarget;
}
/**
* Checks whether this label is the possible successor of the previous
* instruction in the method. This is the case if the predecessor isn't a
* unconditional jump or method exit instruction.
*
* @param label
* label to check
* @return <code>true</code> if the label is a possible instruction
* successor
*/
public static boolean isSuccessor(final Label label) {
final LabelInfo info = get(label);
return info == null ? false : info.successor;
}
/**
* Mark a given label as the beginning of a line with method invocations.
*
* @param label
* label to mark
*/
public static void setMethodInvocationLine(final Label label) {
create(label).methodInvocationLine = true;
}
/**
* Checks whether the a given label has been marked as a line with method
* invocations.
*
* @param label
* label to check
* @return <code>true</code> if the label represents a line with method
* invocations
*/
public static boolean isMethodInvocationLine(final Label label) {
final LabelInfo info = get(label);
return info == null ? false : info.methodInvocationLine;
}
/**
* Determines whether the given label needs a probe to be inserted before.
*
* @param label
* label to test
* @return <code>true</code> if a probe should be inserted before
*/
public static boolean needsProbe(final Label label) {
final LabelInfo info = get(label);
return info != null && info.successor
&& (info.multiTarget || info.methodInvocationLine);
}
/**
* Mark a given label as done.
*
* @param label
* label to mark
*/
public static void setDone(final Label label) {
create(label).done = true;
}
/**
* Resets the "done" status of a given label.
*
* @param label
* label to reset
*/
public static void resetDone(final Label label) {
final LabelInfo info = get(label);
if (info != null) {
info.done = false;
}
}
/**
* Resets the "done" status of all given labels.
*
* @param labels
* labels to reset
*/
public static void resetDone(final Label[] labels) {
for (final Label label : labels) {
resetDone(label);
}
}
/**
* Checks whether this label is marked as done.
*
* @param label
* label to check
* @return <code>true</code> if this label is marked as done
*/
public static boolean isDone(final Label label) {
final LabelInfo info = get(label);
return info == null ? false : info.done;
}
/**
* Sets the given probe id to the given label.
*
* @param label
* label to assign a probe to
* @param id
* id of the probe
*/
public static void setProbeId(final Label label, final int id) {
create(label).probeid = id;
}
/**
* Returns the assigned probe id.
*
* @param label
* label to check
* @return probe id or {@link #NO_PROBE} if no probe is assigned to the
* label
*/
public static int getProbeId(final Label label) {
final LabelInfo info = get(label);
return info == null ? NO_PROBE : info.probeid;
}
/**
* Defines an intermediate label for the given label. Such intermediate
* labels are required during instrumentation to add probes to jump targets.
*
* @param label
* label to define for
* @param intermediate
* intermediate label
*/
public static void setIntermediateLabel(final Label label,
final Label intermediate) {
create(label).intermediate = intermediate;
}
/**
* Returns the intermediate label for the given label if one has been
* defined.
*
* @param label
* label to look for
* @return intermediate label or <code>null</code>
*/
public static Label getIntermediateLabel(final Label label) {
final LabelInfo info = get(label);
return info == null ? null : info.intermediate;
}
/**
* Sets the instruction corresponding to this label.
*
* @param label
* label to set the instruction for
* @param instruction
* corresponding instruction
*/
public static void setInstruction(final Label label,
final Instruction instruction) {
create(label).instruction = instruction;
}
/**
* Returns the corresponding instruction for the given label if one has been
* defined.
*
* @param label
* label to look for
* @return corresponding instruction or <code>null</code>
*/
public static Instruction getInstruction(final Label label) {
final LabelInfo info = get(label);
return info == null ? null : info.instruction;
}
private static LabelInfo get(final Label label) {
final Object info = label.info;
return info instanceof LabelInfo ? (LabelInfo) info : null;
}
private static LabelInfo create(final Label label) {
LabelInfo info = get(label);
if (info == null) {
info = new LabelInfo();
label.info = info;
}
return info;
}
}