Common: Export runtime flag values for data collection purpose. (#1160)

modules/common/apollo_app.cc

@@ -18,14 +18,18 @@
 
 #include <csignal>
 #include <string>
+#include <vector>
 
 #include "gflags/gflags.h"
 #include "modules/common/log.h"
 #include "modules/common/status/status.h"
+#include "modules/common/util/string_util.h"
 #include "modules/hmi/utils/hmi_status_helper.h"
 
 #include "ros/include/ros/ros.h"
 
+DECLARE_string(log_dir);
+
 namespace apollo {
 namespace common {
 
@@ -41,6 +45,21 @@ void ApolloApp::ReportModuleStatus(
   hmi::HMIStatusHelper::ReportModuleStatus(status_);
 }
 
+void ApolloApp::ExportFlags() const {
+  const auto export_file = util::StrCat(FLAGS_log_dir, "/", Name(), ".flags");
+  std::ofstream fout(export_file);
+  CHECK(fout) << "Cannot open file " << export_file;
+
+  std::vector<gflags::CommandLineFlagInfo> flags;
+  gflags::GetAllFlags(&flags);
+  for (const auto &flag : flags) {
+    fout << "# " << flag.type << ", default=" << flag.default_value << "\n"
+         << "# " << flag.description << "\n"
+         << "--" << flag.name << "=" << flag.current_value << "\n"
+         << std::endl;
+  }
+}
+
 int ApolloApp::Spin() {
   ros::AsyncSpinner spinner(callback_thread_num_);
   auto status = Init();
@@ -56,6 +75,7 @@ int ApolloApp::Spin() {
     ReportModuleStatus(apollo::hmi::ModuleStatus::STOPPED);
     return -2;
   }
+  ExportFlags();
   ReportModuleStatus(apollo::hmi::ModuleStatus::STARTED);
   spinner.start();
   ros::waitForShutdown();

modules/common/apollo_app.h

@@ -110,6 +110,12 @@ class ApolloApp {
   /** The callback thread number
    */
   uint32_t callback_thread_num_ = 1;
+
+ private:
+  /**
+   * @brief Export flag values to <FLAGS_log_dir>/<name>.flags.
+   */
+  void ExportFlags() const;
 };
 
 void apollo_app_sigint_handler(int signal_num);