/*
 * Copyright (C) 2016 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 "component_loader/DllLoader.h"

#include <android-base/logging.h>
#include <dlfcn.h>

namespace android {
namespace vts {

DllLoader::DllLoader() : handle_(NULL) {}

DllLoader::~DllLoader() {
  if (!handle_) {
    dlclose(handle_);
    handle_ = NULL;
  }
}

void* DllLoader::Load(const char* file_path) {
  if (!file_path) {
    LOG(ERROR) << "file_path is NULL";
    return NULL;
  }

  // consider using the load mechanism in hardware/libhardware/hardware.c
  handle_ = dlopen(file_path, RTLD_LAZY);
  if (!handle_) {
    LOG(ERROR) << "Can't load a shared library, " << file_path
               << ", error: " << dlerror();
    return NULL;
  }
  LOG(DEBUG) << "DLL loaded " << file_path;
  return handle_;
}

loader_function DllLoader::GetLoaderFunction(const char* function_name) const {
  return (loader_function)LoadSymbol(function_name);
}

loader_function_with_arg DllLoader::GetLoaderFunctionWithArg(
    const char* function_name) const {
  return (loader_function_with_arg)LoadSymbol(function_name);
}

bool DllLoader::SancovResetCoverage() {
  void (*func)() = (void (*)())LoadSymbol("__sanitizer_reset_coverage");
  if (func == NULL) {
    return false;
  }
  func();
  return true;
}

bool DllLoader::GcovInit(writeout_fn wfn, flush_fn ffn) {
  void (*func)(writeout_fn, flush_fn) =
      (void (*)(writeout_fn, flush_fn))LoadSymbol("llvm_gcov_init");
  if (func == NULL) {
    return false;
  }
  func(wfn, ffn);
  return true;
}

bool DllLoader::GcovFlush() {
  void (*func)() = (void (*)()) LoadSymbol("__gcov_flush");
  if (func == NULL) {
    return false;
  }
  func();
  return true;
}

void* DllLoader::LoadSymbol(const char* symbol_name) const {
  const char* error = dlerror();
  if (error != NULL) {
    LOG(ERROR) << "Existing error message " << error << "before loading "
               << symbol_name;
  }
  void* sym = dlsym(handle_, symbol_name);
  if ((error = dlerror()) != NULL) {
    LOG(ERROR) << "Can't find " << symbol_name << " error: " << error;
    return NULL;
  }
  return sym;
}

}  // namespace vts
}  // namespace android