Mercurial > hg > truffle
diff graal/com.oracle.truffle.tools.debug.engine/src/com/oracle/truffle/tools/debug/engine/Breakpoint.java @ 21568:3b8bbf51d320
Truffle/Debugging: add the Truffle DebugEngine and supporting code, as well as add a crude command-line debugging tool used mainly to test the DebugEngine. Migrate the small tols out of project com.oracle.truffle.api into the new project com.oracle.truffle.tools.
author | Michael Van De Vanter <michael.van.de.vanter@oracle.com> |
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date | Tue, 26 May 2015 16:38:13 -0700 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.truffle.tools.debug.engine/src/com/oracle/truffle/tools/debug/engine/Breakpoint.java Tue May 26 16:38:13 2015 -0700 @@ -0,0 +1,238 @@ +/* + * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. Oracle designates this + * particular file as subject to the "Classpath" exception as provided + * by Oracle in the LICENSE file that accompanied this code. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ +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. + * <p> + * 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. + * <p> + * 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. + * <p> + * 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. + * <p> + * 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 <code>true</code> to activate the instrumentation, <code>false</code> 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 + * <em>hit count</em>. Then checks if the <em>ignore count</em> has been exceeded, and if so + * returns {@code true}. If not, it still counts as a <em>hit</em> 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 ? "<none>" : getState().getName()); + if (isOneShot()) { + sb.append(", " + "One-Shot"); + } + if (getCondition() != null) { + sb.append(", condition=\"" + getCondition() + "\""); + } + return sb.toString(); + } +}