diff --git a/src/main/java/gr/gousiosg/javacg/dyn/Graph.java b/src/main/java/gr/gousiosg/javacg/dyn/Graph.java
new file mode 100644
index 0000000..2e9bf05
--- /dev/null
+++ b/src/main/java/gr/gousiosg/javacg/dyn/Graph.java
@@ -0,0 +1,18 @@
+package gr.gousiosg.javacg.dyn;
+
+import java.util.Stack;
+
+public class Graph {
+
+ private static Stack<String> stack = new Stack<String>();
+
+ public static void pushNode(String className, String methodName) {
+ String entry = className + ":" + methodName;
+ System.err.println(stack.peek() + " " + entry);
+ stack.push(entry);
+ }
+
+ public static void popNode() {
+ stack.pop();
+ }
+}
\ No newline at end of file
diff --git a/src/main/java/gr/gousiosg/javacg/dyn/Instrumenter.java b/src/main/java/gr/gousiosg/javacg/dyn/Instrumenter.java
new file mode 100644
index 0000000..5fedb11
--- /dev/null
+++ b/src/main/java/gr/gousiosg/javacg/dyn/Instrumenter.java
@@ -0,0 +1,126 @@
+package gr.gousiosg.javacg.dyn;
+
+import java.lang.instrument.ClassFileTransformer;
+import java.lang.instrument.Instrumentation;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+import javassist.CannotCompileException;
+import javassist.ClassPool;
+import javassist.CtBehavior;
+import javassist.CtClass;
+import javassist.NotFoundException;
+
+public class Instrumenter implements ClassFileTransformer {
+
+ static List<Pattern> pkgIncl = new ArrayList<Pattern>();
+ static List<Pattern> pkgExcl = new ArrayList<Pattern>();
+
+ public static void premain(String argument,
+ Instrumentation instrumentation) {
+
+ //incl=com.foo.*,gr.bar.foo;excl=com.bar.foo.*
+
+ String[] tokens = argument.split(";");
+
+ if (tokens.length <= 1) {
+ System.err.print("Missing delimeter ; from argument:" + tokens);
+ return;
+ }
+
+ for (String token : tokens) {
+ String[] args = token.split("=");
+ if (args.length <= 2) {
+ System.err.print("Missing argument delimeter =:" + token);
+ return;
+ }
+
+ String argtype = args[0];
+
+ if (!argtype.equals("inc") || !argtype.equals("excl")) {
+ System.err.print("wrong argument:" + argtype);
+ return;
+ }
+
+ String[] patterns = args[1].split(",");
+
+ for (String pattern : patterns) {
+ Pattern p = null;
+ try {
+ p = Pattern.compile(pattern);
+ } catch (PatternSyntaxException pse) {
+ System.err.print("pattern: " + pattern + " not valid, ignoring");
+ }
+ if (argtype.equals("inc"))
+ pkgIncl.add(p);
+ else
+ pkgExcl.add(p);
+ }
+ }
+
+ instrumentation.addTransformer(new Instrumenter());
+ }
+
+ public byte[] transform(ClassLoader loader, String className, Class clazz,
+ java.security.ProtectionDomain domain, byte[] bytes) {
+ boolean enhanceClass = false;
+
+ for (Pattern p : pkgIncl) {
+ Matcher m = p.matcher(clazz.getCanonicalName());
+ if (m.matches()) {
+ enhanceClass = true;
+ break;
+ }
+ }
+
+ for (Pattern p : pkgExcl) {
+ Matcher m = p.matcher(clazz.getCanonicalName());
+ if (m.matches()) {
+ enhanceClass = false;
+ break;
+ }
+ }
+
+ if (enhanceClass) {
+ return enhanceClass(className, bytes);
+ } else {
+ return bytes;
+ }
+ }
+
+ private byte[] enhanceClass(String name, byte[] b) {
+ ClassPool pool = ClassPool.getDefault();
+ CtClass clazz = null;
+ try {
+ clazz = pool.makeClass(new java.io.ByteArrayInputStream(b));
+ if (!clazz.isInterface()) {
+ CtBehavior[] methods = clazz.getDeclaredBehaviors();
+ for (int i = 0; i < methods.length; i++) {
+ if (!methods[i].isEmpty()) {
+ enhanceMethod(methods[i], clazz.getName());
+ }
+ }
+ b = clazz.toBytecode();
+ }
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new RuntimeException("Could not instrument " + name
+ + ", exception : " + e.getMessage());
+ } finally {
+ if (clazz != null) {
+ clazz.detach();
+ }
+ }
+ return b;
+ }
+
+ private void enhanceMethod(CtBehavior method, String className)
+ throws NotFoundException, CannotCompileException {
+ method.insertBefore("gr.gousiosg.javacg.dyn.push(\"" + className
+ + "\",\"" + method.getName() + "\");");
+ method.insertAfter("gr.gousiosg.javacg.dyn.pop();");
+ }
+}
\ No newline at end of file
