# HG changeset patch
# User Andreas Woess <andreas.woess@jku.at>
# Date 1379005300 -7200
# Node ID 57674ff0f7e2f32686122688ef7eff8c833a5f4c
# Parent  54dff87002e0f5cc1bc36c8a2a13b771412bf391# Parent  bf7c26dc56e19ab10fb8660366c256082a4e3eb1
Merge

diff -r bf7c26dc56e1 -r 57674ff0f7e2 graal/com.oracle.graal.debug/src/com/oracle/graal/debug/Debug.java
--- a/graal/com.oracle.graal.debug/src/com/oracle/graal/debug/Debug.java	Thu Sep 12 16:09:50 2013 +0200
+++ b/graal/com.oracle.graal.debug/src/com/oracle/graal/debug/Debug.java	Thu Sep 12 19:01:40 2013 +0200
@@ -22,24 +22,49 @@
  */
 package com.oracle.graal.debug;
 
-import com.oracle.graal.debug.internal.*;
+import static com.oracle.graal.debug.Debug.Initialization.*;
 
 import java.io.*;
 import java.util.*;
 import java.util.concurrent.*;
 
+import com.oracle.graal.debug.internal.*;
+
+/**
+ * Scope based debugging facility. This facility is {@link #isEnabled()} if assertions are enabled
+ * for the {@link Debug} class or the {@value Initialization#INITIALIZER_PROPERTY_NAME} system
+ * property is {@code "true"} when {@link Debug} is initialized.
+ */
 public class Debug {
 
-    private static boolean ENABLED = false;
+    /**
+     * Class to assist with initialization of {@link Debug}.
+     */
+    public static class Initialization {
+
+        public static final String INITIALIZER_PROPERTY_NAME = "graal.debug.enable";
 
-    public static void enable() {
-        ENABLED = true;
+        private static boolean initialized;
+
+        /**
+         * Determines if {@link Debug} has been initialized.
+         */
+        public static boolean isDebugInitialized() {
+            return initialized;
+        }
+
     }
 
-    public static void disable() {
-        ENABLED = false;
+    @SuppressWarnings("all")
+    private static boolean initialize() {
+        boolean assertionsEnabled = false;
+        assert assertionsEnabled = true;
+        Initialization.initialized = true;
+        return assertionsEnabled || Boolean.getBoolean(INITIALIZER_PROPERTY_NAME);
     }
 
+    private static final boolean ENABLED = initialize();
+
     public static boolean isEnabled() {
         return ENABLED;
     }
diff -r bf7c26dc56e1 -r 57674ff0f7e2 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotOptions.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotOptions.java	Thu Sep 12 16:09:50 2013 +0200
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotOptions.java	Thu Sep 12 19:01:40 2013 +0200
@@ -183,7 +183,8 @@
      */
     public static void finalizeOptions(boolean ciTime) {
         if (areDebugScopePatternsEnabled() || ciTime) {
-            Debug.enable();
+            assert !Debug.Initialization.isDebugInitialized();
+            System.setProperty(Debug.Initialization.INITIALIZER_PROPERTY_NAME, "true");
         }
     }
 
diff -r bf7c26dc56e1 -r 57674ff0f7e2 graal/com.oracle.graal.printer/src/com/oracle/graal/printer/DebugEnvironment.java
--- a/graal/com.oracle.graal.printer/src/com/oracle/graal/printer/DebugEnvironment.java	Thu Sep 12 16:09:50 2013 +0200
+++ b/graal/com.oracle.graal.printer/src/com/oracle/graal/printer/DebugEnvironment.java	Thu Sep 12 19:01:40 2013 +0200
@@ -34,7 +34,10 @@
 public class DebugEnvironment {
 
     public static void initialize(PrintStream log) {
-        Debug.enable();
+        if (!Debug.isEnabled()) {
+            log.println("WARNING: Scope debugging needs to be enabled with -esa or -D" + Debug.Initialization.INITIALIZER_PROPERTY_NAME + "=true");
+            return;
+        }
         List<DebugDumpHandler> dumpHandlers = new ArrayList<>();
         dumpHandlers.add(new GraphPrinterDumpHandler());
         if (PrintCFG.getValue() || PrintBackendCFG.getValue()) {