Adding JNI code for dalvik.system.DexFile and java.lang.Class

Change-Id: I079c037db77aeaca0dec06660f7551f57adf2607
diff --git a/src/dalvik_system_DexFile.cc b/src/dalvik_system_DexFile.cc
new file mode 100644
index 0000000..3c373d5
--- /dev/null
+++ b/src/dalvik_system_DexFile.cc
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "logging.h"
+#include "ScopedUtfChars.h"
+
+#include "JniConstants.h" // Last to avoid problems with LOG redefinition.
+
+namespace art {
+
+namespace {
+
+// A smart pointer that provides read-only access to a Java string's UTF chars.
+// Unlike libcore's NullableScopedUtfChars, this will *not* throw NullPointerException if
+// passed a null jstring. The correct idiom is:
+//
+//   NullableScopedUtfChars name(env, javaName);
+//   if (env->ExceptionOccurred()) {
+//       return NULL;
+//   }
+//   // ... use name.c_str()
+//
+// TODO: rewrite to get rid of this, or change ScopedUtfChars to offer this option.
+class NullableScopedUtfChars {
+public:
+    NullableScopedUtfChars(JNIEnv* env, jstring s)
+    : mEnv(env), mString(s)
+    {
+        mUtfChars = (s != NULL) ? env->GetStringUTFChars(s, NULL) : NULL;
+    }
+
+    ~NullableScopedUtfChars() {
+        if (mUtfChars) {
+            mEnv->ReleaseStringUTFChars(mString, mUtfChars);
+        }
+    }
+
+    const char* c_str() const {
+        return mUtfChars;
+    }
+
+    size_t size() const {
+        return strlen(mUtfChars);
+    }
+
+    // Element access.
+    const char& operator[](size_t n) const {
+        return mUtfChars[n];
+    }
+
+private:
+    JNIEnv* mEnv;
+    jstring mString;
+    const char* mUtfChars;
+
+    // Disallow copy and assignment.
+    NullableScopedUtfChars(const NullableScopedUtfChars&);
+    void operator=(const NullableScopedUtfChars&);
+};
+
+static jint DexFile_openDexFile(JNIEnv* env, jclass, jstring javaSourceName, jstring javaOutputName) {
+  ScopedUtfChars sourceName(env, javaSourceName);
+  if (sourceName.c_str() == NULL) {
+    return 0;
+  }
+  NullableScopedUtfChars outputName(env, javaOutputName);
+  if (env->ExceptionOccurred()) {
+    return 0;
+  }
+  UNIMPLEMENTED(WARNING) << sourceName.c_str();
+  return 0;
+}
+
+void DexFile_closeDexFile(JNIEnv* env, jclass, jint cookie) {
+  UNIMPLEMENTED(WARNING);
+}
+
+jclass DexFile_defineClass(JNIEnv* env, jclass, jstring javaName, jobject javaLoader, jint cookie) {
+  UNIMPLEMENTED(ERROR);
+  return NULL;
+}
+
+jobjectArray DexFile_getClassNameList(JNIEnv* env, jclass, jint cookie) {
+  UNIMPLEMENTED(ERROR);
+  return NULL;
+}
+
+jboolean DexFile_isDexOptNeeded(JNIEnv* env, jclass, jstring javaFilename) {
+  // TODO: run dex2oat?
+  UNIMPLEMENTED(WARNING);
+  return JNI_FALSE;
+}
+
+static JNINativeMethod gMethods[] = {
+  NATIVE_METHOD(DexFile, closeDexFile, "(I)V"),
+  NATIVE_METHOD(DexFile, defineClass, "(Ljava/lang/String;Ljava/lang/ClassLoader;I)Ljava/lang/Class;"),
+  NATIVE_METHOD(DexFile, getClassNameList, "(I)[Ljava/lang/String;"),
+  NATIVE_METHOD(DexFile, isDexOptNeeded, "(Ljava/lang/String;)Z"),
+  NATIVE_METHOD(DexFile, openDexFile, "(Ljava/lang/String;Ljava/lang/String;I)I"),
+};
+
+}  // namespace
+
+void register_dalvik_system_DexFile(JNIEnv* env) {
+  jniRegisterNativeMethods(env, "dalvik/system/DexFile", gMethods, NELEM(gMethods));
+}
+
+}  // namespace art