--- old/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.debug/src/org/graalvm/compiler/debug/DebugContext.java	2017-11-03 23:56:21.207317682 -0700
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.debug/src/org/graalvm/compiler/debug/DebugContext.java	2017-11-03 23:56:20.669293606 -0700
@@ -29,9 +29,11 @@
 import static org.graalvm.compiler.debug.DebugOptions.Dump;
 import static org.graalvm.compiler.debug.DebugOptions.DumpOnError;
 import static org.graalvm.compiler.debug.DebugOptions.DumpOnPhaseChange;
+import static org.graalvm.compiler.debug.DebugOptions.DumpPath;
 import static org.graalvm.compiler.debug.DebugOptions.ListMetrics;
 import static org.graalvm.compiler.debug.DebugOptions.Log;
 import static org.graalvm.compiler.debug.DebugOptions.MemUseTrackers;
+import static org.graalvm.compiler.debug.DebugOptions.ShowDumpFiles;
 import static org.graalvm.compiler.debug.DebugOptions.Time;
 import static org.graalvm.compiler.debug.DebugOptions.Timers;
 import static org.graalvm.compiler.debug.DebugOptions.TrackMemUse;
@@ -56,6 +58,7 @@
 
 import org.graalvm.compiler.options.OptionKey;
 import org.graalvm.compiler.options.OptionValues;
+import org.graalvm.graphio.GraphOutput;
 import org.graalvm.util.EconomicMap;
 import org.graalvm.util.EconomicSet;
 import org.graalvm.util.Pair;
@@ -98,6 +101,8 @@
     CloseableCounter currentMemUseTracker;
     Scope lastClosedScope;
     Throwable lastExceptionThrown;
+    private IgvDumpChannel sharedChannel;
+    private GraphOutput<?, ?> parentOutput;
 
     /**
      * Stores the {@link MetricKey} values.
@@ -111,6 +116,19 @@
         return immutable.scopesEnabled;
     }
 
+    public <G, N, M> GraphOutput<G, M> buildOutput(GraphOutput.Builder<G, N, M> builder) throws IOException {
+        if (parentOutput != null) {
+            return builder.build(parentOutput);
+        } else {
+            if (sharedChannel == null) {
+                sharedChannel = new IgvDumpChannel(() -> getDumpPath(".bgv", false), immutable.options);
+            }
+            final GraphOutput<G, M> output = builder.build(sharedChannel);
+            parentOutput = output;
+            return output;
+        }
+    }
+
     /**
      * The immutable configuration that can be shared between {@link DebugContext} objects.
      */
@@ -323,6 +341,14 @@
             String compilableName = compilable instanceof JavaMethod ? ((JavaMethod) compilable).format("%H.%n(%p)%R") : String.valueOf(compilable);
             return identifier + ":" + compilableName;
         }
+
+        final String getLabel() {
+            if (compilable instanceof JavaMethod) {
+                JavaMethod method = (JavaMethod) compilable;
+                return method.format("%h.%n(%p)%r");
+            }
+            return String.valueOf(compilable);
+        }
     }
 
     private final Description description;
@@ -394,6 +420,20 @@
         }
     }
 
+    public Path getDumpPath(String extension, boolean directory) {
+        try {
+            String id = description == null ? null : description.identifier;
+            String label = description == null ? null : description.getLabel();
+            Path result = PathUtilities.createUnique(immutable.options, DumpPath, id, label, extension, directory);
+            if (ShowDumpFiles.getValue(immutable.options)) {
+                TTY.println("Dumping debug output to %s", result.toAbsolutePath().toString());
+            }
+            return result;
+        } catch (IOException ex) {
+            throw rethrowSilently(RuntimeException.class, ex);
+        }
+    }
+
     /**
      * A special dump level that indicates the dumping machinery is enabled but no dumps will be
      * produced except through other options.
@@ -2043,4 +2083,9 @@
         }
         out.println();
     }
+
+    @SuppressWarnings({"unused", "unchecked"})
+    private static <E extends Exception> E rethrowSilently(Class<E> type, Throwable ex) throws E {
+        throw (E) ex;
+    }
 }