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      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "component_loader/DllLoader.h"
     18 
     19 #include <android-base/logging.h>
     20 #include <dlfcn.h>
     21 
     22 namespace android {
     23 namespace vts {
     24 
     25 DllLoader::DllLoader() : handle_(NULL) {}
     26 
     27 DllLoader::~DllLoader() {
     28   if (!handle_) {
     29     dlclose(handle_);
     30     handle_ = NULL;
     31   }
     32 }
     33 
     34 void* DllLoader::Load(const char* file_path) {
     35   if (!file_path) {
     36     LOG(ERROR) << "file_path is NULL";
     37     return NULL;
     38   }
     39 
     40   // consider using the load mechanism in hardware/libhardware/hardware.c
     41   handle_ = dlopen(file_path, RTLD_LAZY);
     42   if (!handle_) {
     43     LOG(ERROR) << "Can't load a shared library, " << file_path
     44                << ", error: " << dlerror();
     45     return NULL;
     46   }
     47   LOG(DEBUG) << "DLL loaded " << file_path;
     48   return handle_;
     49 }
     50 
     51 loader_function DllLoader::GetLoaderFunction(const char* function_name) const {
     52   return (loader_function)LoadSymbol(function_name);
     53 }
     54 
     55 loader_function_with_arg DllLoader::GetLoaderFunctionWithArg(
     56     const char* function_name) const {
     57   return (loader_function_with_arg)LoadSymbol(function_name);
     58 }
     59 
     60 bool DllLoader::SancovResetCoverage() {
     61   void (*func)() = (void (*)())LoadSymbol("__sanitizer_reset_coverage");
     62   if (func == NULL) {
     63     return false;
     64   }
     65   func();
     66   return true;
     67 }
     68 
     69 bool DllLoader::GcovInit(writeout_fn wfn, flush_fn ffn) {
     70   void (*func)(writeout_fn, flush_fn) =
     71       (void (*)(writeout_fn, flush_fn))LoadSymbol("llvm_gcov_init");
     72   if (func == NULL) {
     73     return false;
     74   }
     75   func(wfn, ffn);
     76   return true;
     77 }
     78 
     79 bool DllLoader::GcovFlush() {
     80   void (*func)() = (void (*)()) LoadSymbol("__gcov_flush");
     81   if (func == NULL) {
     82     return false;
     83   }
     84   func();
     85   return true;
     86 }
     87 
     88 void* DllLoader::LoadSymbol(const char* symbol_name) const {
     89   const char* error = dlerror();
     90   if (error != NULL) {
     91     LOG(ERROR) << "Existing error message " << error << "before loading "
     92                << symbol_name;
     93   }
     94   void* sym = dlsym(handle_, symbol_name);
     95   if ((error = dlerror()) != NULL) {
     96     LOG(ERROR) << "Can't find " << symbol_name << " error: " << error;
     97     return NULL;
     98   }
     99   return sym;
    100 }
    101 
    102 }  // namespace vts
    103 }  // namespace android
    104