--- a/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/Debugger.java	Wed Sep 16 12:27:08 2015 +0200
+++ b/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/debug/Debugger.java	Wed Sep 16 15:36:22 2015 -0700
@@ -24,6 +24,13 @@
  */
 package com.oracle.truffle.api.debug;
 
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.Truffle;
 import com.oracle.truffle.api.TruffleLanguage;
@@ -35,6 +42,7 @@
 import com.oracle.truffle.api.instrument.AdvancedInstrumentRoot;
 import com.oracle.truffle.api.instrument.AdvancedInstrumentRootFactory;
 import com.oracle.truffle.api.instrument.Instrument;
+import com.oracle.truffle.api.instrument.Instrumenter;
 import com.oracle.truffle.api.instrument.KillException;
 import com.oracle.truffle.api.instrument.Probe;
 import com.oracle.truffle.api.instrument.StandardSyntaxTag;
@@ -43,12 +51,6 @@
 import com.oracle.truffle.api.nodes.Node;
 import com.oracle.truffle.api.source.LineLocation;
 import com.oracle.truffle.api.source.Source;
-import java.io.Closeable;
-import java.io.IOException;
-import java.io.PrintStream;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
 
 /**
  * Represents debugging related state of a {@link com.oracle.truffle.api.vm.TruffleVM}. Instance of
@@ -60,7 +62,7 @@
 public final class Debugger {
 
     private static final boolean TRACE = false;
-    private static final String TRACE_PREFIX = "DEBUG ENGINE: ";
+    private static final String TRACE_PREFIX = "Debugger: ";
 
     private static final PrintStream OUT = System.out;
 
@@ -73,6 +75,7 @@
         }
     }
 
+    private final Instrumenter instrumenter;
     private final Object vm;
     private Source lastSource;
 
@@ -92,6 +95,9 @@
         void addWarning(String warning);
     }
 
+    private final BreakpointCallback breakpointCallback;
+    private final WarningLog warningLog;
+
     /**
      * Implementation of line-oriented breakpoints.
      */
@@ -107,9 +113,9 @@
      */
     private DebugExecutionContext debugContext;
 
-    Debugger(Object vm) {
+    Debugger(Object vm, Instrumenter instrumenter) {
         this.vm = vm;
-
+        this.instrumenter = instrumenter;
         Source.setFileCaching(true);
 
         // Initialize execution context stack
@@ -117,7 +123,7 @@
         prepareContinue();
         debugContext.contextTrace("START EXEC DEFAULT");
 
-        final BreakpointCallback breakpointCallback = new BreakpointCallback() {
+        breakpointCallback = new BreakpointCallback() {
 
             @TruffleBoundary
             public void haltedAt(Node astNode, MaterializedFrame mFrame, String haltReason) {
@@ -125,7 +131,7 @@
             }
         };
 
-        final WarningLog warningLog = new WarningLog() {
+        warningLog = new WarningLog() {
 
             public void addWarning(String warning) {
                 assert debugContext != null;
@@ -137,10 +143,6 @@
         this.tagBreaks = new TagBreakpointFactory(this, breakpointCallback, warningLog);
     }
 
-    Object vm() {
-        return vm;
-    }
-
     /**
      * Sets a breakpoint to halt at a source line.
      *
@@ -269,6 +271,7 @@
         debugContext.setStrategy(new StepOver(stepCount));
     }
 
+    // TODO (mlvdv) used by the breakpoint factories; to be deprecated/replaced.
     /**
      * Creates a language-specific factory to produce instances of {@link AdvancedInstrumentRoot}
      * that, when executed, computes the result of a textual expression in the language; used to
@@ -284,15 +287,12 @@
      */
     @SuppressWarnings("rawtypes")
     AdvancedInstrumentRootFactory createAdvancedInstrumentRootFactory(Probe probe, String expr, AdvancedInstrumentResultListener resultListener) throws IOException {
-        try {
-            Class<? extends TruffleLanguage> langugageClass = ACCESSOR.findLanguage(probe);
-            TruffleLanguage.Env env = ACCESSOR.findLanguage(vm, langugageClass);
-            TruffleLanguage<?> l = ACCESSOR.findLanguage(env);
-            DebugSupportProvider dsp = ACCESSOR.getDebugSupport(l);
-            return dsp.createAdvancedInstrumentRootFactory(expr, resultListener);
-        } catch (DebugSupportException ex) {
-            throw new IOException(ex);
-        }
+        Class<? extends TruffleLanguage> languageClass = ACCESSOR.findLanguage(probe);
+        return ACCESSOR.createAdvancedInstrumentRootFactory(vm, languageClass, expr, resultListener);
+    }
+
+    Instrumenter getInstrumenter() {
+        return instrumenter;
     }
 
     /**
@@ -416,7 +416,7 @@
 
         @Override
         protected void setStrategy(final int stackDepth) {
-            Probe.setBeforeTagTrap(new SyntaxTagTrap(STEPPING_TAG) {
+            instrumenter.setBeforeTagTrap(new SyntaxTagTrap(STEPPING_TAG) {
                 @TruffleBoundary
                 @Override
                 public void tagTrappedAt(Node node, MaterializedFrame mFrame) {
@@ -430,7 +430,7 @@
                     strategyTrace("RESUME BEFORE", "");
                 }
             });
-            Probe.setAfterTagTrap(new SyntaxTagTrap(CALL_TAG) {
+            instrumenter.setAfterTagTrap(new SyntaxTagTrap(CALL_TAG) {
                 @TruffleBoundary
                 @Override
                 public void tagTrappedAt(Node node, MaterializedFrame mFrame) {
@@ -449,8 +449,8 @@
 
         @Override
         protected void unsetStrategy() {
-            Probe.setBeforeTagTrap(null);
-            Probe.setAfterTagTrap(null);
+            instrumenter.setBeforeTagTrap(null);
+            instrumenter.setAfterTagTrap(null);
         }
     }
 
@@ -473,7 +473,7 @@
 
         @Override
         protected void setStrategy(final int stackDepth) {
-            Probe.setAfterTagTrap(new SyntaxTagTrap(CALL_TAG) {
+            instrumenter.setAfterTagTrap(new SyntaxTagTrap(CALL_TAG) {
 
                 @TruffleBoundary
                 @Override
@@ -491,7 +491,7 @@
 
         @Override
         protected void unsetStrategy() {
-            Probe.setAfterTagTrap(null);
+            instrumenter.setAfterTagTrap(null);
         }
     }
 
@@ -517,7 +517,7 @@
 
         @Override
         protected void setStrategy(final int stackDepth) {
-            Probe.setBeforeTagTrap(new SyntaxTagTrap(STEPPING_TAG) {
+            instrumenter.setBeforeTagTrap(new SyntaxTagTrap(STEPPING_TAG) {
                 @TruffleBoundary
                 @Override
                 public void tagTrappedAt(Node node, MaterializedFrame mFrame) {
@@ -542,7 +542,7 @@
                 }
             });
 
-            Probe.setAfterTagTrap(new SyntaxTagTrap(CALL_TAG) {
+            instrumenter.setAfterTagTrap(new SyntaxTagTrap(CALL_TAG) {
                 @TruffleBoundary
                 @Override
                 public void tagTrappedAt(Node node, MaterializedFrame mFrame) {
@@ -563,8 +563,8 @@
 
         @Override
         protected void unsetStrategy() {
-            Probe.setBeforeTagTrap(null);
-            Probe.setAfterTagTrap(null);
+            instrumenter.setBeforeTagTrap(null);
+            instrumenter.setAfterTagTrap(null);
         }
     }
 
@@ -592,7 +592,7 @@
 
         @Override
         protected void setStrategy(final int stackDepth) {
-            Probe.setBeforeTagTrap(new SyntaxTagTrap(STEPPING_TAG) {
+            instrumenter.setBeforeTagTrap(new SyntaxTagTrap(STEPPING_TAG) {
                 @TruffleBoundary
                 @Override
                 public void tagTrappedAt(Node node, MaterializedFrame mFrame) {
@@ -613,7 +613,7 @@
 
         @Override
         protected void unsetStrategy() {
-            Probe.setBeforeTagTrap(null);
+            instrumenter.setBeforeTagTrap(null);
         }
     }
 
@@ -813,7 +813,8 @@
         protected Closeable executionStart(Object vm, Debugger[] fillIn, Source s) {
             final Debugger d;
             if (fillIn[0] == null) {
-                d = fillIn[0] = new Debugger(vm);
+                final Instrumenter instrumenter = ACCESSOR.getInstrumenter(vm);
+                d = fillIn[0] = new Debugger(vm, instrumenter);
             } else {
                 d = fillIn[0];
             }
@@ -842,8 +843,14 @@
         }
 
         @Override
-        protected DebugSupportProvider getDebugSupport(TruffleLanguage<?> l) {
-            return super.getDebugSupport(l);
+        protected Instrumenter getInstrumenter(Object vm) {
+            return super.getInstrumenter(vm);
+        }
+
+        @Override
+        protected AdvancedInstrumentRootFactory createAdvancedInstrumentRootFactory(Object vm, Class<? extends TruffleLanguage> languageClass, String expr,
+                        AdvancedInstrumentResultListener resultListener) throws IOException {
+            return super.createAdvancedInstrumentRootFactory(vm, languageClass, expr, resultListener);
         }
 
         @Override