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*
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package com.oracle.truffle.tools.debug.engine;
import com.oracle.truffle.api.instrument.*;
import com.oracle.truffle.api.source.*;
public abstract class Breakpoint {
/**
* A general model of the states occupied by a breakpoint during its lifetime.
*/
public enum BreakpointState {
/**
* Not attached, enabled.
*
* Created for a source location but not yet attached: perhaps just created and the source
* hasn't been loaded yet; perhaps source has been loaded, but the line location isn't
* probed so a breakpoint cannot be attached. Can be either enabled or disabled.
*/
ENABLED_UNRESOLVED("Enabled/Unresolved"),
/**
* Not attached, disabled.
*
* Created for a source location but not yet attached: perhaps just created and the source
* hasn't been loaded yet; perhaps source has been loaded, but the line location isn't
* probed so a breakpoint cannot be attached.
*/
DISABLED_UNRESOLVED("Disabled/Unresolved"),
/**
* Attached, instrument enabled.
*
* Is currently implemented by some {@link Instrument}, which is attached to a {@link Probe}
* at a specific node in the AST, and the breakpoint is enabled.
*/
ENABLED("Enabled"),
/**
* Attached, instrument disabled.
*
* Is currently implemented by some {@link Instrument}, which is attached to a {@link Probe}
* at a specific node in the AST, and the breakpoint is disabled.
*/
DISABLED("Disabled"),
/**
* Not attached, instrument is permanently disabled.
*/
DISPOSED("Disposed");
private final String name;
BreakpointState(String name) {
this.name = name;
}
public String getName() {
return name;
}
@Override
public String toString() {
return name;
}
}
private static int nextBreakpointId = 0;
private final int id;
private final int groupId;
private final boolean isOneShot;
private int ignoreCount;
private int hitCount = 0;
private BreakpointState state;
Breakpoint(BreakpointState state, int groupId, int ignoreCount, boolean isOneShot) {
this.state = state;
this.id = nextBreakpointId++;
this.groupId = groupId;
this.isOneShot = isOneShot;
this.ignoreCount = ignoreCount;
}
/**
* Unique ID.
*/
public final int getId() {
return id;
}
/**
* Group ID, set when created.
*/
public final int getGroupId() {
return groupId;
}
/**
* Enables or disables this breakpoint's AST instrumentation. The breakpoint is enabled by
* default.
*
* @param enabled true to activate the instrumentation, false to
* deactivate the instrumentation so that it has no effect.
*/
public abstract void setEnabled(boolean enabled);
/**
* Is this breakpoint active?
*/
public abstract boolean isEnabled();
/**
* Sets the condition on this breakpoint, {@code null} to make it unconditional.
*
* @param expr if non{@code -null}, a boolean expression, expressed in the guest language, to be
* evaluated in the lexical context at the breakpoint location.
* @throws DebugException if condition is invalid
* @throws UnsupportedOperationException if the breakpoint does not support conditions
*/
public abstract void setCondition(String expr) throws DebugException;
/**
* Gets the string, expressed in the Guest Language, that defines the current condition on this
* breakpoint; {@code null} if this breakpoint is currently unconditional.
*/
public String getCondition() {
return null;
}
/**
* Does this breakpoint remove itself after first activation?
*/
public final boolean isOneShot() {
return isOneShot;
}
/**
* Gets the number of hits left to be ignored before halting.
*/
public final int getIgnoreCount() {
return ignoreCount;
}
/**
* Change the threshold for when this breakpoint should start causing a break. When both an
* ignore count and a {@linkplain #setCondition(String) condition} are specified, the condition
* is evaluated first: if {@code false} it is not considered to be a hit. In other words, the
* ignore count is for successful conditions only.
*/
public final void setIgnoreCount(int ignoreCount) {
this.ignoreCount = ignoreCount;
}
/**
* Number of times this breakpoint has reached, with one exception; if the breakpoint has a
* condition that evaluates to {@code false}, it does not count as a hit.
*/
public final int getHitCount() {
return hitCount;
}
/**
* Disables this breakpoint and removes any associated instrumentation; it becomes permanently
* inert.
*/
public abstract void dispose();
/**
* Gets a human-sensible description of this breakpoint's location in a {@link Source}.
*/
public abstract String getLocationDescription();
public final BreakpointState getState() {
return state;
}
final void assertState(BreakpointState s) {
assert state == s;
}
final void setState(BreakpointState state) {
this.state = state;
}
/**
* Assumes that all conditions for causing the break have been satisfied, so increments the
* hit count. Then checks if the ignore count has been exceeded, and if so
* returns {@code true}. If not, it still counts as a hit but should be ignored.
*
* @return whether to proceed
*/
final boolean incrHitCountCheckIgnore() {
return ++hitCount > ignoreCount;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder(getClass().getSimpleName());
sb.append(" state=");
sb.append(getState() == null ? "" : getState().getName());
if (isOneShot()) {
sb.append(", " + "One-Shot");
}
if (getCondition() != null) {
sb.append(", condition=\"" + getCondition() + "\"");
}
return sb.toString();
}
}