Index: interpret.cc
===================================================================
--- interpret.cc	(revision 146634)
+++ interpret.cc	(working copy)
@@ -983,7 +983,7 @@
 _Jv_InterpMethod::run (void *retp, INTERP_FFI_RAW_TYPE *args,
 		       _Jv_InterpMethod *meth)
 {
-#undef DEBUG
+#undef __GCJ_DEBUG
 #undef DEBUG_LOCALS_INSN
 #define DEBUG_LOCALS_INSN(s, t) do {} while (0)
 
@@ -994,7 +994,7 @@
 _Jv_InterpMethod::run_debug (void *retp, INTERP_FFI_RAW_TYPE *args,
 			     _Jv_InterpMethod *meth)
 {
-#define DEBUG
+#define __GCJ_DEBUG
 #undef DEBUG_LOCALS_INSN
 #define DEBUG_LOCALS_INSN(s, t)  \
   do    \
@@ -1719,7 +1719,7 @@
    CATCH_LOCATION with the method and location where the catch will
    occur. If the exception is not caught, these are set to 0.
 
-   This function should only be used with the DEBUG interpreter. */
+   This function should only be used with the __GCJ_DEBUG interpreter. */
 static void
 find_catch_location (::java::lang::Throwable *exc, jthread thread,
 		     jmethodID *catch_method, jlong *catch_loc)
@@ -1751,7 +1751,7 @@
    caught (if it is caught).
    
    Like find_catch_location, this should only be called with the
-   DEBUG interpreter. Since a few exceptions occur outside the
+   __GCJ_DEBUG interpreter. Since a few exceptions occur outside the
    interpreter proper, it is important to not call this function
    without checking JVMTI_REQUESTED_EVENT(Exception) first. */
 void
Index: configure.ac
===================================================================
--- configure.ac	(revision 146634)
+++ configure.ac	(working copy)
@@ -244,7 +244,7 @@
   AS_HELP_STRING([--enable-libgcj-debug],
                  [enable runtime debugging code]),
   [if test "$enable_libgcj_debug" = yes; then
-    AC_DEFINE(DEBUG, 1, [Define this if you want runtime debugging enabled.])
+    AC_DEFINE(__GCJ_DEBUG, 1, [Define this if you want runtime debugging enabled.])
     LIBGCJDEBUG="enable"
   fi])
 
Index: include/java-assert.h
===================================================================
--- include/java-assert.h	(revision 146634)
+++ include/java-assert.h	(working copy)
@@ -16,7 +16,7 @@
 void _Jv_Abort (const char *, const char *, int, const char *)
   __attribute__ ((__noreturn__));
 
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
 #define _Jv_AssertDoCall(Message) _Jv_Abort (__FUNCTION__, __FILE__, __LINE__, Message)
 
 #define JvAssertMessage(Expr, Message) \
@@ -26,13 +26,13 @@
 
 #define JvFail(Message) _Jv_AssertDoCall (Message)
 
-#else /* DEBUG */
+#else /* __GCJ_DEBUG */
 
 #define _Jv_AssertDoCall(Message)
 #define JvAssertMessage(Expr, Message)
 #define JvAssert(Expr)
 #define JvFail(Message) _Jv_Abort (0, 0, 0, Message)
 
-#endif /* not DEBUG */
+#endif /* not __GCJ_DEBUG */
 
 #endif /* __JAVA_ASSERT_H__ */
Index: prims.cc
===================================================================
--- prims.cc	(revision 146634)
+++ prims.cc	(working copy)
@@ -460,7 +460,7 @@
 
 
 
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
 void
 _Jv_Abort (const char *function, const char *file, int line,
 	   const char *message)
@@ -469,7 +469,7 @@
 _Jv_Abort (const char *, const char *, int, const char *message)
 #endif
 {
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
   fprintf (stderr,
 	   "libgcj failure: %s\n   in function %s, file %s, line %d\n",
 	   message, function, file, line);
Index: gnu/classpath/natConfiguration.cc
===================================================================
--- gnu/classpath/natConfiguration.cc	(revision 146634)
+++ gnu/classpath/natConfiguration.cc	(working copy)
@@ -25,7 +25,7 @@
 jboolean
 gnu::classpath::Configuration::debug()
 {
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
   return true;
 #else
   return false;
Index: interpret-run.cc
===================================================================
--- interpret-run.cc	(revision 146634)
+++ interpret-run.cc	(working copy)
@@ -23,7 +23,7 @@
   // returns.
   java::lang::Thread *thread = java::lang::Thread::currentThread();
   
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
   _Jv_InterpFrame frame_desc (meth, thread, NULL, &pc);
 #else
   _Jv_InterpFrame frame_desc (meth, thread);
@@ -38,7 +38,7 @@
 
   _Jv_word locals[meth->max_locals];
 
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
   // This is the information needed to get and set local variables with
   // proper type checking.
   frame_desc.locals = locals;
@@ -126,7 +126,7 @@
           continue;
         }
     }
-#endif /* DEBUG */
+#endif /* __GCJ_DEBUG */
 
 #define INSN_LABEL(op) &&insn_##op
 
@@ -347,7 +347,7 @@
 
 #ifdef DIRECT_THREADED
 
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
 #undef NEXT_INSN
 #define NEXT_INSN							\
   do									\
@@ -392,7 +392,7 @@
 
 #undef INTERP_REPORT_EXCEPTION
 #define INTERP_REPORT_EXCEPTION(Jthrowable) REPORT_EXCEPTION (Jthrowable)
-#else // !DEBUG
+#else // !__GCJ_DEBUG
 #undef NEXT_INSN
 #define NEXT_INSN goto *((pc++)->insn)
 
@@ -416,7 +416,7 @@
 
 #undef INTERP_REPORT_EXCEPTION
 #define INTERP_REPORT_EXCEPTION(Jthrowable) /* not needed when not debugging */
-#endif // !DEBUG
+#endif // !__GCJ_DEBUG
 
 #define INTVAL() ((pc++)->int_val)
 #define AVAL() ((pc++)->datum)
@@ -450,7 +450,7 @@
 
 #else
 
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
 #define NEXT_INSN							\
   do									\
     {									\
@@ -2677,7 +2677,7 @@
         {
           sp = stack;
           sp++->o = ex; // Push exception.
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
           if (JVMTI_REQUESTED_EVENT (ExceptionCatch))
             {
               using namespace gnu::gcj::jvmti;
Index: java/io/natVMObjectInputStream.cc
===================================================================
--- java/io/natVMObjectInputStream.cc	(revision 146634)
+++ java/io/natVMObjectInputStream.cc	(working copy)
@@ -26,7 +26,7 @@
 #include <java/lang/reflect/Method.h>
 #include <java-stack.h>
 
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
 #include <java/lang/System.h>
 #include <java/io/PrintStream.h>
 #endif