Implement can_generate_native_method_bind capability

This capability lets one observe and even replace the implementations
of native methods when they are bound.

Test: ./test.py --host -j40

Bug: 37432636
Change-Id: I2432a8e4da1a677e8011ce495296f4ab9f42eb3e

1 files changed, 110 insertions, 0 deletions

diff --git a/test/986-native-method-bind/native_bind.cc b/test/986-native-method-bind/native_bind.cc
new file mode 100644
index 0000000000..4f93f87dfe
--- /dev/null
+++ b/test/986-native-method-bind/native_bind.cc
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2017 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 <inttypes.h>
+#include <memory>
+#include <stdio.h>
+#include <dlfcn.h>
+
+#include "android-base/stringprintf.h"
+#include "jni.h"
+#include "jvmti.h"
+
+// Test infrastructure
+#include "jni_binder.h"
+#include "jvmti_helper.h"
+#include "test_env.h"
+#include "scoped_local_ref.h"
+
+namespace art {
+namespace Test986NativeBind {
+
+static void doUpPrintCall(JNIEnv* env, const char* function) {
+  ScopedLocalRef<jclass> klass(env, env->FindClass("art/Test986"));
+  jmethodID targetMethod = env->GetStaticMethodID(klass.get(), function, "()V");
+  env->CallStaticVoidMethod(klass.get(), targetMethod);
+}
+
+extern "C" JNIEXPORT void JNICALL Java_art_Test986_00024Transform_sayHi(
+    JNIEnv* env, jclass klass ATTRIBUTE_UNUSED) {
+  doUpPrintCall(env, "doSayHi");
+}
+
+extern "C" JNIEXPORT void JNICALL NoReallySayGoodbye(JNIEnv* env, jclass klass ATTRIBUTE_UNUSED) {
+  doUpPrintCall(env, "doSayBye");
+}
+
+static void doJvmtiMethodBind(jvmtiEnv* jvmtienv ATTRIBUTE_UNUSED,
+                              JNIEnv* env,
+                              jthread thread ATTRIBUTE_UNUSED,
+                              jmethodID m,
+                              void* address,
+                              /*out*/void** out_address) {
+  ScopedLocalRef<jclass> method_class(env, env->FindClass("java/lang/reflect/Method"));
+  ScopedLocalRef<jobject> method_obj(env, env->ToReflectedMethod(method_class.get(), m, false));
+  Dl_info addr_info;
+  if (dladdr(address, &addr_info) == 0 || addr_info.dli_sname == nullptr) {
+    ScopedLocalRef<jclass> exception_class(env, env->FindClass("java/lang/Exception"));
+    env->ThrowNew(exception_class.get(), "dladdr failure!");
+    return;
+  }
+  ScopedLocalRef<jstring> sym_name(env, env->NewStringUTF(addr_info.dli_sname));
+  ScopedLocalRef<jclass> klass(env, env->FindClass("art/Test986"));
+  jmethodID upcallMethod = env->GetStaticMethodID(
+      klass.get(),
+      "doNativeMethodBind",
+      "(Ljava/lang/reflect/Method;Ljava/lang/String;)Ljava/lang/String;");
+  if (env->ExceptionCheck()) {
+    return;
+  }
+  ScopedLocalRef<jstring> new_symbol(env,
+                                     reinterpret_cast<jstring>(
+                                         env->CallStaticObjectMethod(klass.get(),
+                                                                 upcallMethod,
+                                                                 method_obj.get(),
+                                                                 sym_name.get())));
+  const char* new_symbol_chars = env->GetStringUTFChars(new_symbol.get(), nullptr);
+  if (strcmp(new_symbol_chars, addr_info.dli_sname) != 0) {
+    *out_address = dlsym(RTLD_DEFAULT, new_symbol_chars);
+    if (*out_address == nullptr) {
+      ScopedLocalRef<jclass> exception_class(env, env->FindClass("java/lang/Exception"));
+      env->ThrowNew(exception_class.get(), "dlsym failure!");
+      return;
+    }
+  }
+  env->ReleaseStringUTFChars(new_symbol.get(), new_symbol_chars);
+}
+
+extern "C" JNIEXPORT void JNICALL Java_art_Test986_setupNativeBindNotify(
+    JNIEnv* env ATTRIBUTE_UNUSED, jclass klass ATTRIBUTE_UNUSED) {
+  jvmtiEventCallbacks cb;
+  memset(&cb, 0, sizeof(cb));
+  cb.NativeMethodBind = doJvmtiMethodBind;
+  jvmti_env->SetEventCallbacks(&cb, sizeof(cb));
+}
+
+extern "C" JNIEXPORT void JNICALL Java_art_Test986_setNativeBindNotify(
+    JNIEnv* env, jclass klass ATTRIBUTE_UNUSED, jboolean enable) {
+  jvmtiError res = jvmti_env->SetEventNotificationMode(enable ? JVMTI_ENABLE : JVMTI_DISABLE,
+                                                       JVMTI_EVENT_NATIVE_METHOD_BIND,
+                                                       nullptr);
+  if (res != JVMTI_ERROR_NONE) {
+    JvmtiErrorToException(env, jvmti_env, res);
+  }
+}
+
+}  // namespace Test986NativeBind
+}  // namespace art