--- a/langtools/make/Makefile	Thu May 14 10:58:12 2009 -0700
+++ b/langtools/make/Makefile	Fri May 15 13:30:55 2009 -0700
@@ -105,6 +105,11 @@
   endif
 endif
 
+ifeq ($(DEBUG_CLASSFILES), true)
+  ANT_OPTIONS += -Djavac.debug=true
+  ANT_OPTIONS += -Ddebug.classfiles=true
+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/langtools/make/build.xml	Thu May 14 10:58:12 2009 -0700
+++ b/langtools/make/build.xml	Fri May 15 13:30:55 2009 -0700
@@ -32,6 +32,13 @@
 
 <project name="langtools" default="build" basedir="..">
     
+    <!-- Force full debuginfo for javac if the debug.classfiles
+    property is set.  This must be BEFORE the include of
+    build.properties because it sets javac.debuglevel.  -->
+    <condition property="javac.debuglevel" value="source,lines,vars">
+        <equals arg1="${debug.classfiles}" arg2="true"/>
+    </condition>
+
     <!-- The following locations can be used to override default property values. -->
 
     <!-- Use this location for customizations specific to this instance of this workspace -->