Merge "Allow vendors to extend the list of public libs"

namespace android {

#if defined(__ANDROID__)

static constexpr const char* kPublicNativeLibrariesConfig = "/system/etc/public.libraries.txt";

static constexpr const char* kPublicNativeLibrariesSystemConfig = "/system/etc/public.libraries.txt";

static constexpr const char* kPublicNativeLibrariesVendorConfig = "/vendor/etc/public.libraries.txt";

class LibraryNamespaces {

 public:

  }

  void Initialize() {

    std::vector<std::string> sonames;

    LOG_ALWAYS_FATAL_IF(!ReadConfig(kPublicNativeLibrariesSystemConfig, &sonames),

                        "Error reading public native library list from \"%s\": %s",

                        kPublicNativeLibrariesSystemConfig, strerror(errno));

    // This file is optional, quietly ignore if the file does not exist.

    ReadConfig(kPublicNativeLibrariesVendorConfig, &sonames);

    // android_init_namespaces() expects all the public libraries

    // to be loaded so that they can be found by soname alone.

    //

    // TODO(dimitry): this is a bit misleading since we do not know

    // if the vendor public library is going to be opened from /vendor/lib

    // we might as well end up loading them from /system/lib

    // For now we rely on CTS test to catch things like this but

    // it should probably be addressed in the future.

    for (const auto& soname : sonames) {

      dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE);

    }

    public_libraries_ = base::Join(sonames, ':');

  }

 private:

  bool ReadConfig(const std::string& configFile, std::vector<std::string>* sonames) {

    // Read list of public native libraries from the config file.

    std::string file_content;

    LOG_ALWAYS_FATAL_IF(!base::ReadFileToString(kPublicNativeLibrariesConfig, &file_content),

                        "Error reading public native library list from \"%s\": %s",

                        kPublicNativeLibrariesConfig, strerror(errno));

    if(!base::ReadFileToString(configFile, &file_content)) {

      return false;

    }

    std::vector<std::string> lines = base::Split(file_content, "\n");

    std::vector<std::string> sonames;

    for (const auto& line : lines) {

      auto trimmed_line = base::Trim(line);

      if (trimmed_line[0] == '#' || trimmed_line.empty()) {

        continue;

      }

      sonames.push_back(trimmed_line);

      sonames->push_back(trimmed_line);

    }

    public_libraries_ = base::Join(sonames, ':');

    // android_init_namespaces() expects all the public libraries

    // to be loaded so that they can be found by soname alone.

    for (const auto& soname : sonames) {

      dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE);

    }

    return true;

  }

 private:

  bool InitPublicNamespace(const char* library_path) {

    // (http://b/25844435) - Some apps call dlopen from generated code (mono jited

    // code is one example) unknown to linker in which  case linker uses anonymous