1 files changed, 205 insertions, 0 deletions
diff --git a/tools/dump-coverage/dump_coverage.cc b/tools/dump-coverage/dump_coverage.cc
new file mode 100644
index 000000000000..0808e776f190
--- /dev/null
+++ b/tools/dump-coverage/dump_coverage.cc
@@ -0,0 +1,205 @@
+// Copyright (C) 2018 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 <android-base/logging.h>
+#include <jni.h>
+#include <jvmti.h>
+#include <string.h>
+
+#include <fstream>
+
+using std::get;
+using std::tuple;
+
+namespace dump_coverage {
+
+#define CHECK_JVMTI(x) CHECK_EQ((x), JVMTI_ERROR_NONE)
+#define CHECK_NOTNULL(x) CHECK((x) != nullptr)
+#define CHECK_NO_EXCEPTION(env) CHECK(!(env)->ExceptionCheck());
+
+static JavaVM* java_vm = nullptr;
+
+// Get the current JNI environment.
+static JNIEnv* GetJNIEnv() {
+  JNIEnv* env = nullptr;
+  CHECK_EQ(java_vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6),
+           JNI_OK);
+  return env;
+}
+
+// Get the JaCoCo Agent class and an instance of the class, given a JNI
+// environment.
+// Will crash if the Agent isn't found or if any Java Exception occurs.
+static tuple<jclass, jobject> GetJavaAgent(JNIEnv* env) {
+  jclass java_agent_class =
+      env->FindClass("org/jacoco/agent/rt/internal/Agent");
+  CHECK_NOTNULL(java_agent_class);
+
+  jmethodID java_agent_get_instance =
+      env->GetStaticMethodID(java_agent_class, "getInstance",
+                             "()Lorg/jacoco/agent/rt/internal/Agent;");
+  CHECK_NOTNULL(java_agent_get_instance);
+
+  jobject java_agent_instance =
+      env->CallStaticObjectMethod(java_agent_class, java_agent_get_instance);
+  CHECK_NO_EXCEPTION(env);
+  CHECK_NOTNULL(java_agent_instance);
+
+  return tuple(java_agent_class, java_agent_instance);
+}
+
+// Runs equivalent of Agent.getInstance().getExecutionData(false) and returns
+// the result.
+// Will crash if the Agent isn't found or if any Java Exception occurs.
+static jbyteArray GetExecutionData(JNIEnv* env) {
+  auto java_agent = GetJavaAgent(env);
+  jmethodID java_agent_get_execution_data =
+      env->GetMethodID(get<0>(java_agent), "getExecutionData", "(Z)[B");
+  CHECK_NO_EXCEPTION(env);
+  CHECK_NOTNULL(java_agent_get_execution_data);
+
+  jbyteArray java_result_array = (jbyteArray)env->CallObjectMethod(
+      get<1>(java_agent), java_agent_get_execution_data, false);
+  CHECK_NO_EXCEPTION(env);
+
+  return java_result_array;
+}
+
+// Writes the execution data to a file.
+//  data, length: represent the data, as a sequence of bytes.
+//  filename: file to write coverage data to.
+//  returns JNI_ERR if there is an error in writing the file, otherwise JNI_OK.
+static jint WriteFile(const char* data, int length, const std::string& filename) {
+  LOG(INFO) << "Writing file of length " << length << " to '" << filename
+            << "'";
+  std::ofstream file(filename, std::ios::binary);
+
+  if (!file.is_open()) {
+    LOG(ERROR) << "Could not open file: '" << filename << "'";
+    return JNI_ERR;
+  }
+  file.write(data, length);
+  file.close();
+
+  if (!file) {
+    LOG(ERROR) << "I/O error in reading file";
+    return JNI_ERR;
+  }
+
+  LOG(INFO) << "Done writing file";
+  return JNI_OK;
+}
+
+// Grabs execution data and writes it to a file.
+//  filename: file to write coverage data to.
+//  returns JNI_ERR if there is an error writing the file.
+// Will crash if the Agent isn't found or if any Java Exception occurs.
+static jint Dump(const std::string& filename) {
+  LOG(INFO) << "Dumping file";
+
+  JNIEnv* env = GetJNIEnv();
+  jbyteArray java_result_array = GetExecutionData(env);
+  CHECK_NOTNULL(java_result_array);
+
+  jbyte* result_ptr = env->GetByteArrayElements(java_result_array, 0);
+  CHECK_NOTNULL(result_ptr);
+
+  int result_len = env->GetArrayLength(java_result_array);
+
+  return WriteFile((const char*) result_ptr, result_len, filename);
+}
+
+// Resets execution data, performing the equivalent of
+//  Agent.getInstance().reset();
+//  args: should be empty.
+//  returns JNI_ERR if the arguments are invalid.
+// Will crash if the Agent isn't found or if any Java Exception occurs.
+static jint Reset(const std::string& args) {
+  if (args != "") {
+    LOG(ERROR) << "reset takes no arguments, but received '" << args << "'";
+    return JNI_ERR;
+  }
+
+  JNIEnv* env = GetJNIEnv();
+  auto java_agent = GetJavaAgent(env);
+
+  jmethodID java_agent_reset =
+      env->GetMethodID(get<0>(java_agent), "reset", "()V");
+  CHECK_NOTNULL(java_agent_reset);
+
+  env->CallVoidMethod(get<1>(java_agent), java_agent_reset);
+  CHECK_NO_EXCEPTION(env);
+  return JNI_OK;
+}
+
+// Given a string of the form "<a>:<b>" returns (<a>, <b>).
+// Given a string <a> that doesn't contain a colon, returns (<a>, "").
+static tuple<std::string, std::string> SplitOnColon(const std::string& options) {
+  size_t loc_delim = options.find(':');
+  std::string command, args;
+
+  if (loc_delim == std::string::npos) {
+    command = options;
+  } else {
+    command = options.substr(0, loc_delim);
+    args = options.substr(loc_delim + 1, options.length());
+  }
+  return tuple(command, args);
+}
+
+// Parses and executes a command specified by options of the form
+// "<command>:<args>" where <command> is either "dump" or "reset".
+static jint ParseOptionsAndExecuteCommand(const std::string& options) {
+  auto split = SplitOnColon(options);
+  auto command = get<0>(split), args = get<1>(split);
+
+  LOG(INFO) << "command: '" << command << "' args: '" << args << "'";
+
+  if (command == "dump") {
+    return Dump(args);
+  }
+
+  if (command == "reset") {
+    return Reset(args);
+  }
+
+  LOG(ERROR) << "Invalid command: expected 'dump' or 'reset' but was '"
+             << command << "'";
+  return JNI_ERR;
+}
+
+static jint AgentStart(JavaVM* vm, char* options) {
+  android::base::InitLogging(/* argv= */ nullptr);
+  java_vm = vm;
+
+  return ParseOptionsAndExecuteCommand(options);
+}
+
+// Late attachment (e.g. 'am attach-agent').
+extern "C" JNIEXPORT jint JNICALL
+Agent_OnAttach(JavaVM* vm, char* options, void* reserved ATTRIBUTE_UNUSED) {
+  return AgentStart(vm, options);
+}
+
+// Early attachment.
+extern "C" JNIEXPORT jint JNICALL
+Agent_OnLoad(JavaVM* jvm ATTRIBUTE_UNUSED, char* options ATTRIBUTE_UNUSED, void* reserved ATTRIBUTE_UNUSED) {
+  LOG(ERROR)
+    << "The dumpcoverage agent will not work on load,"
+    << " as it does not have access to the runtime.";
+  return JNI_ERR;
+}
+
+}  // namespace dump_coverage