Fix 086-null-super and 087-gc-after-link

Parallel run-test means that the dex files for 086 and 087 are no longer
always in test.jar. Correct the behavior of the class linker when
Classloader.loadClass returns null to be the behavior of Dalvik.

Change-Id: Icf6363e118d03a01060012ac558b5f1a484d74f9

4 files changed, 39 insertions, 7 deletions

diff --git a/src/class_linker.cc b/src/class_linker.cc
index 1355cbf..b06d108 100644
--- a/src/class_linker.cc
+++ b/src/class_linker.cc
@@ -91,6 +91,14 @@ void ThrowNoSuchFieldError(const StringPiece& scope, Class* c, const StringPiece
   Thread::Current()->ThrowNewException("Ljava/lang/NoSuchFieldError;", msg.str().c_str());
 }
 
+void ThrowNullPointerException(const char* fmt, ...) __attribute__((__format__(__printf__, 1, 2)));
+void ThrowNullPointerException(const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  Thread::Current()->ThrowNewExceptionV("Ljava/lang/NullPointerException;", fmt, args);
+  va_end(args);
+}
+
 void ThrowEarlierClassFailure(Class* c) {
   /*
    * The class failed to initialize on a previous attempt, so we want to throw
@@ -1152,7 +1160,13 @@ Class* ClassLinker::FindClass(const char* descriptor, const ClassLoader* class_l
     }
     ScopedLocalRef<jobject> class_loader_object(env, AddLocalReference<jobject>(env, class_loader));
     ScopedLocalRef<jobject> result(env, env->CallObjectMethod(class_loader_object.get(), mid, class_name_object.get()));
-    if (!env->ExceptionOccurred()) {
+    if (result.get() == NULL) {
+      // broken loader - throw NPE to be compatible with Dalvik
+      ThrowNullPointerException("ClassLoader.loadClass returned null for %s",
+                                class_name_string.c_str());
+      return NULL;
+    } else if (!env->ExceptionOccurred()) {
+      // success, return Class*
       return Decode<Class*>(env, result.get());
     } else {
       env->ExceptionClear();  // Failed to find class fall-through to NCDFE
@@ -2299,9 +2313,7 @@ bool ClassLinker::LoadSuperAndInterfaces(SirtRef<Class>& klass, const DexFile& d
   CHECK_EQ(Class::kStatusIdx, klass->GetStatus());
   StringPiece descriptor(dex_file.StringByTypeIdx(klass->GetDexTypeIndex()));
   const DexFile::ClassDef* class_def = dex_file.FindClassDef(descriptor);
-  if (class_def == NULL) {
-    return false;
-  }
+  CHECK(class_def != NULL);
   uint16_t super_class_idx = class_def->superclass_idx_;
   if (super_class_idx != DexFile::kDexNoIndex16) {
     Class* super_class = ResolveType(dex_file, super_class_idx, klass.get());
@@ -2901,7 +2913,8 @@ Class* ClassLinker::ResolveType(const DexFile& dex_file,
       //       same name to be loaded simultaneously by different loaders
       dex_cache->SetResolvedType(type_idx, resolved);
     } else {
-      DCHECK(Thread::Current()->IsExceptionPending());
+      CHECK(Thread::Current()->IsExceptionPending())
+          << "Expected pending exception for failed resolution of: " << descriptor;
     }
   }
   return resolved;
diff --git a/src/dalvik_system_DexFile.cc b/src/dalvik_system_DexFile.cc
index 7fce25f..7680e0f 100644
--- a/src/dalvik_system_DexFile.cc
+++ b/src/dalvik_system_DexFile.cc
@@ -176,7 +176,26 @@ jclass DexFile_defineClass(JNIEnv* env, jclass, jstring javaName, jobject javaLo
   class_linker->RegisterDexFile(*dex_file);
   Class* result = class_linker->DefineClass(descriptor, class_loader, *dex_file, *dex_class_def);
   if (env->ExceptionCheck()) {
+    // Remember exception and clear it
+    jthrowable exception = env->ExceptionOccurred();
     env->ExceptionClear();
+    // If we threw a "class not found" exception, stifle it, since the contract in the higher
+    // method says we simply return null if the class is not found.
+    static const char* ignored_exception_classes[2] = {
+        "java/lang/ClassNotFoundException",
+        "java/lang/NoClassDefFoundError"
+    };
+    bool clear_exception = false;
+    for (int i = 0; i < 2; i++) {
+      jclass exception_class = env->FindClass(ignored_exception_classes[i]);
+      if (env->IsInstanceOf(exception, exception_class)) {
+        clear_exception = true;
+        break;
+      }
+    }
+    if (!clear_exception) {
+      env->Throw(exception);
+    }
     return NULL;
   }
   return AddLocalReference<jclass>(env, result);
diff --git a/test/086-null-super/src/Main.java b/test/086-null-super/src/Main.java
index 6decb20..0b8b2f5 100644
--- a/test/086-null-super/src/Main.java
+++ b/test/086-null-super/src/Main.java
@@ -55,7 +55,7 @@ public class Main {
         private static final String CLASS_NAME =
                 "Main$BrokenDexLoader$Inaccessible";
 
-        private static final String DEX_FILE = "test.jar";
+        private static final String DEX_FILE = "/data/art-test/086-null-super.jar";
 
         public BrokenDexLoader(ClassLoader parent) {
             super(parent);
diff --git a/test/087-gc-after-link/src/Main.java b/test/087-gc-after-link/src/Main.java
index dc68f9f..12fa56a 100644
--- a/test/087-gc-after-link/src/Main.java
+++ b/test/087-gc-after-link/src/Main.java
@@ -55,7 +55,7 @@ public class Main {
         private static final String CLASS_NAME =
                 "Main$BrokenDexLoader$Inaccessible";
 
-        private static final String DEX_FILE = "test.jar";
+        private static final String DEX_FILE = "/data/art-test/087-gc-after-link.jar";
 
         public BrokenDexLoader(ClassLoader parent) {
             super(parent);