--- a/graal/com.oracle.graal.compiler.test/src/com/oracle/graal/compiler/test/TypeSystemTest.java	Sat Apr 13 22:16:04 2013 +0200
+++ b/graal/com.oracle.graal.compiler.test/src/com/oracle/graal/compiler/test/TypeSystemTest.java	Sun Apr 14 22:38:34 2013 +0200
@@ -205,21 +205,20 @@
         }
     }
 
-    // CheckStyle: stop system..print check
     public static void outputGraph(StructuredGraph graph, String message) {
-        System.out.println("========================= " + message);
+        TTY.println("========================= " + message);
         SchedulePhase schedule = new SchedulePhase();
         schedule.apply(graph);
         for (Block block : schedule.getCFG().getBlocks()) {
-            System.out.print("Block " + block + " ");
+            TTY.print("Block " + block + " ");
             if (block == schedule.getCFG().getStartBlock()) {
-                System.out.print("* ");
+                TTY.print("* ");
             }
-            System.out.print("-> ");
+            TTY.print("-> ");
             for (Block succ : block.getSuccessors()) {
-                System.out.print(succ + " ");
+                TTY.print(succ + " ");
             }
-            System.out.println();
+            TTY.println();
             for (Node node : schedule.getBlockToNodesMap().get(block)) {
                 outputNode(node);
             }
@@ -227,11 +226,11 @@
     }
 
     private static void outputNode(Node node) {
-        System.out.print("  " + node + "    (usage count: " + node.usages().count() + ") (inputs:");
+        TTY.print("  " + node + "    (usage count: " + node.usages().count() + ") (inputs:");
         for (Node input : node.inputs()) {
-            System.out.print(" " + input.toString(Verbosity.Id));
+            TTY.print(" " + input.toString(Verbosity.Id));
         }
-        System.out.println(")");
+        TTY.println(")");
         if (node instanceof MergeNode) {
             for (PhiNode phi : ((MergeNode) node).phis()) {
                 outputNode(phi);
@@ -239,7 +238,6 @@
         }
     }
 
-    // CheckStyle: resume system..print check
     private <T extends Node & Node.IterableNodeType> void test(String snippet, Class<T> clazz) {
         StructuredGraph graph = parse(snippet);
         Debug.dump(graph, "Graph");

--- a/graal/com.oracle.graal.graph/.checkstyle_checks.xml	Sat Apr 13 22:16:04 2013 +0200
+++ b/graal/com.oracle.graal.graph/.checkstyle_checks.xml	Sun Apr 14 22:38:34 2013 +0200
@@ -9,7 +9,7 @@
     Description: none
 -->
 <module name="Checker">
-  <property name="severity" value="warning"/>
+  <property name="severity" value="error"/>
   <module name="TreeWalker">
     <property name="tabWidth" value="4"/>
     <module name="FileContentsHolder"/>

--- a/graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/phases/ea/PartialEscapeAnalysisPhase.java	Sat Apr 13 22:16:04 2013 +0200
+++ b/graal/com.oracle.graal.virtual/src/com/oracle/graal/virtual/phases/ea/PartialEscapeAnalysisPhase.java	Sun Apr 14 22:38:34 2013 +0200
@@ -181,14 +181,13 @@
                 }
             }
         }
-        // CheckStyle: stop system..print check
         boolean success = true;
         for (Node node : obsoleteNodes) {
             if (flood.isMarked(node)) {
-                System.out.print("offending node path:");
+                TTY.print("offending node path:");
                 Node current = node;
                 while (current != null) {
-                    System.out.println(current.toString());
+                    TTY.println(current.toString());
                     current = path.get(current);
                     if (current != null && current instanceof FixedNode && !obsoleteNodes.contains(current)) {
                         break;
@@ -197,7 +196,6 @@
                 success = false;
             }
         }
-        // CheckStyle: resume system..print check
         return success;
     }