More debugging stuff

Author: nr-kateanderson

newrelic-agent/src/main/java/com/newrelic/agent/instrumentation/weaver/ClassLoaderClassTransformer.java

@@ -292,7 +292,9 @@ public byte[] transform(ClassLoader loader, String className, Class<?> classBein
         String superName = reader.getClassName().equals("java/lang/ClassLoader") ? reader.getClassName() : reader.getSuperName();
         if (observedClassLoaders.containsKey(superName) ||
                 classloadersToInclude.contains(reader.getClassName()) || classloadersToInclude.contains(superName)) {
-            return transform(loader, className, classBeingRedefined, protectionDomain, classfileBuffer, null, null);
+            byte[] finalClassBytes = transform(loader, className, classBeingRedefined, protectionDomain, classfileBuffer, null, null);
+            //WeaveUtils.createReadableClassFileFromByteArray(finalClassBytes, true, className, "ClassLoader", "/Users/katherineanderson/Downloads");
+            return finalClassBytes;
         }
         return null;
     }
@@ -322,6 +324,12 @@ public byte[] transform(ClassLoader loader, String className, Class<?> classBein
             // This ClassCache will only consult the map of the observedClassLoaders that we pass in, so
             // we don't need to worry about it possibly using findResource() when we call validate(cache).
             ClassCache cache = new ClassCache(new ClassLoaderClassFinder(observedClassLoaders));
+
+            //DEBUG TIME: how does the base classloader fare???
+            if(className.equals("java/lang/ClassLoader")){
+                WeaveUtils.forceVisitationOfClassFile(classfileBuffer, cache);
+            }
+
             PackageValidationResult result;
             if (className.equals("java/lang/ClassLoader")) {
                 // For "java.lang.ClassLoader" we only want to instrument one of the loadClass() methods

newrelic-weaver/src/main/java/com/newrelic/weave/ClassWeave.java

@@ -72,6 +72,7 @@ public static ClassWeave weave(PreparedMatch match,
     }
 
     private void weave() {
+        WeaveUtils.createReadableClassFileFromClassNode(target, false, target.name, "ClassLoader", "/Users/katherineanderson/Downloads");
         weavedMethods.clear();
         // copy target to composite without any jsr instructions
         target.accept(new ClassVisitor(WeaveUtils.ASM_API_LEVEL, composite) {

newrelic-weaver/src/main/java/com/newrelic/weave/utils/PatchedClassWriter.java

@@ -21,6 +21,8 @@
  * the class structure without actually loading any classes.
  */
 class PatchedClassWriter extends ClassWriter {
+    private final String THROWABLE_NAME = "java/lang/Throwable";
+    private final String EXCEPTION_NAME = "java/lang/Exception";
     private final ClassInformationFinder classInfoFinder;
 
     PatchedClassWriter(int flags, ClassInformationFinder classInfoFinder) {
@@ -55,6 +57,9 @@ class PatchedClassWriter extends ClassWriter {
 
     @Override
     protected String getCommonSuperClass(final String type1, final String type2) {
+        if ((type1.equals(THROWABLE_NAME) && type2.equals(EXCEPTION_NAME)) || (type2.equals(THROWABLE_NAME) && type1.equals(EXCEPTION_NAME))){
+            System.out.println("Comparing an Exception and a Throwable.");
+        }
         if (type1.equals(type2)) {
             return type1;
         }
@@ -105,6 +110,9 @@ protected String getCommonSuperClass(final String type1, final String type2) {
         }
 
         if (null == commonSuperType) {
+            if ((type1.equals(THROWABLE_NAME) && type2.equals(EXCEPTION_NAME)) || (type2.equals(THROWABLE_NAME) && type1.equals(EXCEPTION_NAME))) {
+                return THROWABLE_NAME;
+            }
             return WeaveUtils.JAVA_LANG_OBJECT_NAME;
         }
 

newrelic-weaver/src/main/java/com/newrelic/weave/utils/WeaveUtils.java

@@ -603,6 +603,12 @@ public static void printClassFrames(byte [] classBytes) {
 
     //TEMPORARY
 
+    public static void forceVisitationOfClassFile(byte[] classBytes, ClassInformationFinder classInfoFinder) {
+        ClassReader reader = new ClassReader(classBytes);
+        ClassWriter cw = new PatchedClassWriter(ClassWriter.COMPUTE_FRAMES, classInfoFinder);
+        reader.accept(cw, ClassReader.EXPAND_FRAMES);
+    }
+
     public static void getInstructionAtBCI(int bci, byte [] classBytes) {
         int bciMargin = 3;
         ClassReader reader = new ClassReader(classBytes);
@@ -629,21 +635,22 @@ public static void getInstructionAtBCI(int bci, byte [] classBytes) {
         }
     }
 
-    public static void createReadableClassFileFromClassNode(ClassNode cn, String originalName, String targetName, String destDir) {
+    public static void createReadableClassFileFromClassNode(ClassNode cn, boolean isNew, String originalName, String targetName, String destDir) {
         if (targetName == null || originalName.contains(targetName)) {
             System.out.println("Weaved composite ClassLoader");
             ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
             cn.accept(cw);
             byte[] classBytes = cw.toByteArray();
-            createReadableClassFileFromByteArray(classBytes, originalName, null, destDir);
+            createReadableClassFileFromByteArray(classBytes, isNew, originalName, null, destDir);
         }
     }
 
-    public static void createReadableClassFileFromByteArray(byte[] classBytes, String originalName, String targetName, String destDir){
+    public static void createReadableClassFileFromByteArray(byte[] classBytes, boolean isNew, String originalName, String targetName, String destDir){
+        String suffix = isNew ? ".new" : ".old";
         if (targetName == null || originalName.contains(targetName)) {
             final File MY_DIRECTORY = new File(destDir);
             try {
-                File newFile = File.createTempFile(originalName.replace('/', '_'), ".new", MY_DIRECTORY);
+                File newFile = File.createTempFile(originalName.replace('/', '_'), suffix, MY_DIRECTORY);
                 PrintWriter pw = new PrintWriter(newFile);
                 ClassReader cr = new ClassReader(classBytes);
                 org.objectweb.asm.util.TraceClassVisitor mv = new org.objectweb.asm.util.TraceClassVisitor(pw);