--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.tools/src/com/oracle/truffle/tools/LineToProbesMap.java	Tue May 26 16:38:13 2015 -0700
@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2014, 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;
+
+import java.io.*;
+import java.util.*;
+
+import com.oracle.truffle.api.instrument.*;
+import com.oracle.truffle.api.instrument.impl.*;
+import com.oracle.truffle.api.source.*;
+
+/**
+ * An {@link InstrumentationTool} that builds a map of every {@link Probe} attached to some AST,
+ * indexed by {@link Source} and line number.
+ */
+public final class LineToProbesMap extends InstrumentationTool {
+
+    private static final boolean TRACE = false;
+    private static final PrintStream OUT = System.out;
+
+    private static void trace(String msg) {
+        OUT.println("LineToProbesMap: " + msg);
+    }
+
+    /**
+     * Map: Source line ==> probes associated with source sections starting on the line.
+     */
+    private final Map<LineLocation, Collection<Probe>> lineToProbesMap = new HashMap<>();
+
+    private final ProbeListener probeListener;
+
+    /**
+     * Create a map of {@link Probe}s that collects information on all probes added to subsequently
+     * created ASTs (once installed).
+     */
+    public LineToProbesMap() {
+        this.probeListener = new LineToProbesListener();
+    }
+
+    @Override
+    protected boolean internalInstall() {
+        Probe.addProbeListener(probeListener);
+        return true;
+    }
+
+    @Override
+    protected void internalReset() {
+        lineToProbesMap.clear();
+    }
+
+    @Override
+    protected void internalDispose() {
+        Probe.removeProbeListener(probeListener);
+    }
+
+    /**
+     * Returns the {@link Probe}, if any, associated with a specific line of guest language code; if
+     * more than one, return the one with the first starting character location.
+     */
+    public Probe findFirstProbe(LineLocation lineLocation) {
+        Probe probe = null;
+        final Collection<Probe> probes = findProbes(lineLocation);
+        for (Probe probesOnLine : probes) {
+            if (probe == null) {
+                probe = probesOnLine;
+            } else if (probesOnLine.getProbedSourceSection().getCharIndex() < probe.getProbedSourceSection().getCharIndex()) {
+                probe = probesOnLine;
+            }
+        }
+        return probe;
+    }
+
+    /**
+     * Returns all {@link Probe}s whose associated source begins at the given {@link LineLocation},
+     * an empty list if none.
+     */
+    public Collection<Probe> findProbes(LineLocation line) {
+        final Collection<Probe> probes = lineToProbesMap.get(line);
+        if (probes == null) {
+            return Collections.emptyList();
+        }
+        return Collections.unmodifiableCollection(probes);
+    }
+
+    private class LineToProbesListener extends DefaultProbeListener {
+
+        @Override
+        public void newProbeInserted(Probe probe) {
+            final SourceSection sourceSection = probe.getProbedSourceSection();
+            if (sourceSection != null && !(sourceSection instanceof NullSourceSection)) {
+                final LineLocation lineLocation = sourceSection.getLineLocation();
+                if (TRACE) {
+                    trace("ADD " + lineLocation.getShortDescription() + " ==> " + probe.getShortDescription());
+                }
+                Collection<Probe> probes = lineToProbesMap.get(lineLocation);
+                if (probes == null) {
+                    probes = new ArrayList<>(2);
+                    lineToProbesMap.put(lineLocation, probes);
+                } else {
+                    assert !probes.contains(probe);
+                }
+                probes.add(probe);
+            }
+        }
+    }
+}