diff --git a/app/build.xml b/app/build.xml
index b4567b87e..ca41d0580 100644
--- a/app/build.xml
+++ b/app/build.xml
@@ -1,15 +1,38 @@
 <?xml version="1.0"?>
 <project name="Processing PDE" default="build">
 
-	<property name="generated" value="${basedir}/generated/processing/app/antlr"/>
-	<property name="grammars" value="${basedir}/grammars"/>
-	<property name="antlrjar" value="${basedir}/lib/antlr.jar"/>
-	
+	<property name="generated" value="${basedir}/generated/processing/app/antlr" />
+	<property name="grammars" value="${basedir}/grammars" />
+	<property name="antlrjar" value="${basedir}/lib/antlr.jar" />
+
 	<classloader taskname="antlr">
 		<classpath path="lib/antlr.jar" />
 	</classloader>
 
 	<target name="clean" description="Clean the build directories">
+
+		<!-- jdf sez: clean up after old layout of generated resources -->
+		<delete failonerror="false">
+			<fileset dir="${basedir}/src/antlr/java">
+				<include name="*.java" />
+				<include name="*.tokens" />
+				<include name="*.txt" />
+				<include name="*.g" />
+				<include name="*.smap" />
+			</fileset>
+		</delete>
+		<delete failonerror="false">
+			<!-- jdf sez: don't name anything FooRecognizer or FooLexer in this package -->
+			<fileset dir="${basedir}/src/processing/app/preproc">
+				<include name="*Recognizer.java" />
+				<include name="*Lexer.java" />
+				<include name="*.tokens" />
+				<include name="*.txt" />
+				<include name="*.g" />
+				<include name="*.smap" />
+			</fileset>
+		</delete>
+
 		<delete dir="bin" />
 		<delete file="pde.jar" />
 		<delete>
@@ -23,18 +46,11 @@
 		</delete>
 	</target>
 
-	<target name="preproc" description="Compile ANTLR grammar">
+	<target name="preproc" depends="clean" description="Compile ANTLR grammar">
 		<antlr target="${grammars}/java15.g" outputdirectory="${generated}">
 			<classpath path="${antlrjar}" />
 		</antlr>
-
-		<!-- antlr wants this file nearby -->
-<!--		<copy todir="src/processing/app/preproc" file="src/antlr/java/JavaTokenTypes.txt" />
--->
-		
-		<antlr target="${grammars}/pde.g" 
-				outputdirectory="${generated}" 
-				glib="${grammars}/java15.g">
+		<antlr target="${grammars}/pde.g" outputdirectory="${generated}" glib="${grammars}/java15.g">
 			<classpath path="${antlrjar}" />
 		</antlr>
 	</target>
@@ -43,7 +59,8 @@
 		<condition property="core-built">
 			<available file="../core/core.jar" />
 		</condition>
-		<fail unless="core-built" message="Please build the core library first and make sure it sits in ../core/core.jar" />
+		<fail unless="core-built" 
+			message="Please build the core library first and make sure it sits in ../core/core.jar" />
 
 		<mkdir dir="bin" />
 
@@ -74,19 +91,17 @@
     <echo message="override ${env.JAVA_HOME}/lib/tools.jar" />
     <fail />
 -->
-		<javac 
-			target="1.5" 
-			destdir="bin" 
-			excludes="**/tools/format/**" 
-			encoding="UTF-8" 
-			includeAntRuntime="false" 
-			classpath="../core/core.jar; ${env.JAVA_HOME}/lib/tools.jar; lib/ant.jar; lib/ant-launcher.jar; lib/antlr.jar; lib/apple.jar; lib/ecj.jar; lib/jna.jar" 
-		>
-			<src path="src"/>
-			<src path="generated"/>
+		<javac target="1.5" 
+				destdir="bin" 
+				excludes="**/tools/format/**" 
+				encoding="UTF-8" 
+				includeAntRuntime="false" 
+				classpath="../core/core.jar; ${env.JAVA_HOME}/lib/tools.jar; lib/ant.jar; lib/ant-launcher.jar; lib/antlr.jar; lib/apple.jar; lib/ecj.jar; lib/jna.jar"
+				>
+			<src path="src" />
+			<src path="generated" />
 		</javac>
-		<javac 
-			target="1.5" 
+		<javac target="1.5" 
 			srcdir="../android/tool/src" 
 			destdir="bin" 
 			encoding="UTF-8"