--- a/make/Makefile	Thu Apr 16 11:22:46 2009 -0700
+++ b/make/Makefile	Fri Apr 17 15:56:06 2009 +0100
@@ -69,6 +69,14 @@ else
   endif
 endif
 
+ifeq ($(DEBUG_CLASSFILES), true)
+  ANT_OPTIONS += -Djavac.debug=true
+  ANT_OPTIONS += -Djavac.debuglevel=source,lines,vars
+else
+  ANT_OPTIONS += -Djavac.debug=false
+  ANT_OPTIONS += -Djavac.debuglevel=
+endif
+
 # Note: jdk/make/common/Defs.gmk uses LANGUAGE_VERSION (-source NN)
 # and the somewhat misnamed CLASS_VERSION (-target NN)
 ifdef TARGET_CLASS_VERSION

--- a/make/build.xml	Thu Apr 16 11:22:46 2009 -0700
+++ b/make/build.xml	Fri Apr 17 15:56:06 2009 +0100
@@ -98,6 +98,7 @@
              destdir="${build.classes.dir}"
              memoryInitialSize="${javac.memoryInitialSize}"
              memoryMaximumSize="${javac.memoryMaximumSize}"
+	     debug="${javac.debug}"
              target="${javac.target}"
              excludes="com/sun/tools/internal/txw2/**">
          <compilerarg value="-J-Xbootclasspath/p:${bootstrap.dir}/lib/javac.jar"/>