Add set_fatal_error_callback to public Log interface.

GitOrigin-RevId: 3e7c3bb97d86fa753deae864fdf574de1de1aee4

CMakeLists.txt

@@ -652,7 +652,7 @@ if (NOT CMAKE_CROSSCOMPILING)
     target_include_directories(tg_cli SYSTEM PRIVATE ${READLINE_INCLUDE_DIR})
     target_compile_definitions(tg_cli PRIVATE -DUSE_READLINE=1)
   endif()
-  target_link_libraries(tg_cli PRIVATE memprof tdcore tdtl)
+  target_link_libraries(tg_cli PRIVATE memprof tdclient tdcore tdtl)
   add_dependencies(tg_cli tl_generate_json)
 endif()
 

td/telegram/Log.cpp

@@ -17,6 +17,12 @@ namespace td {
 static FileLog file_log;
 static TsLog ts_log(&file_log);
 static int64 max_log_file_size = 10 << 20;
+static Log::FatalErrorCallbackPtr fatal_error_callback;
+
+static void fatal_error_callback_wrapper(CSlice message) {
+  CHECK(fatal_error_callback != nullptr);
+  fatal_error_callback(message.c_str());
+}
 
 void Log::set_file_path(string file_path) {
   if (file_path.empty()) {
@@ -37,4 +43,14 @@ void Log::set_verbosity_level(int new_verbosity_level) {
   SET_VERBOSITY_LEVEL(VERBOSITY_NAME(FATAL) + new_verbosity_level);
 }
 
+void Log::set_fatal_error_callback(FatalErrorCallbackPtr callback) {
+  if (callback == nullptr) {
+    fatal_error_callback = nullptr;
+    set_log_fatal_error_callback(nullptr);
+  } else {
+    fatal_error_callback = callback;
+    set_log_fatal_error_callback(fatal_error_callback_wrapper);
+  }
+}
+
 }  // namespace td

td/telegram/Log.h

@@ -56,6 +56,24 @@ class Log {
    *                                 value greater than 5 and up to 1024 can be used to enable even more logging.
    */
   static void set_verbosity_level(int new_verbosity_level);
+
+  /**
+   * A type of callback function that will be called when a fatal error happens.
+   *
+   * \param error_message Null-terminated string with a description of a happened fatal error.
+   */
+  using FatalErrorCallbackPtr = void (*)(const char *error_message);
+
+  /**
+   * Sets the callback that will be called when a fatal error happens.
+   * None of the TDLib methods can be called from the callback.
+   * The TDLib will crash as soon as callback returns.
+   * By default the callback is not set.
+   *
+   * \param[in]  callback Callback that will be called when a fatal error happens.
+   *                      Pass nullptr to remove the callback.
+   */
+  static void set_fatal_error_callback(FatalErrorCallbackPtr callback);
 };
 
 }  // namespace td

td/telegram/cli.cpp

@@ -5,6 +5,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 #include "td/telegram/ClientActor.h"
+#include "td/telegram/Log.h"
 
 #include "td/telegram/td_api_json.h"
 
@@ -42,6 +43,7 @@
 #include <cstdlib>
 #include <cstring>  // for strcmp
 #include <ctime>
+#include <iostream>
 #include <limits>
 #include <memory>
 #include <queue>
@@ -56,7 +58,7 @@
 
 namespace td {
 
-void dump_memory_usage() {
+static void dump_memory_usage() {
   if (is_memprof_on()) {
     LOG(WARNING) << "memory_dump";
     clear_thread_locals();
@@ -87,7 +89,7 @@ static int32 saved_point;
 static string saved_line;
 static std::atomic_flag readline_lock = ATOMIC_FLAG_INIT;
 
-void deactivate_readline() {
+static void deactivate_readline() {
   while (readline_lock.test_and_set(std::memory_order_acquire)) {
     // spin
   }
@@ -100,7 +102,7 @@ void deactivate_readline() {
   rl_redisplay();
 }
 
-void reactivate_readline() {
+static void reactivate_readline() {
   rl_set_prompt(prompt);
   rl_replace_line(saved_line.c_str(), 0);
   rl_point = saved_point;
@@ -109,7 +111,7 @@ void reactivate_readline() {
   readline_lock.clear(std::memory_order_release);
 }
 
-char *command_generator(const char *text, int state) {
+static char *command_generator(const char *text, int state) {
   static vector<CSlice> commands{"GetContacts",
                                  "GetChats",
                                  "GetHistory",
@@ -162,7 +164,7 @@ char *command_generator(const char *text, int state) {
   return nullptr;
 }
 
-char **tg_cli_completion(const char *text, int start, int end) {
+static char **tg_cli_completion(const char *text, int start, int end) {
   char **matches = nullptr;
   if (start == 0) {
     matches = rl_completion_matches(text, command_generator);
@@ -2751,6 +2753,10 @@ class CliClient final : public Actor {
       quit();
     } else if (op == "dnq" || op == "DumpNetQueries") {
       dump_pending_network_queries();
+    } else if (op == "fatal") {
+      LOG(FATAL) << "Fatal!";
+    } else if (op == "unreachable") {
+      UNREACHABLE();
     } else {
       op_not_found_count++;
     }
@@ -2864,26 +2870,31 @@ class CliClient final : public Actor {
 };
 CliClient *CliClient::instance_ = nullptr;
 
-void quit() {
+static void quit() {
   CliClient::quit_instance();
 }
 
-void fail_signal(int sig) {
+static void fail_signal(int sig) {
   signal_safe_write_signal_number(sig);
   while (true) {
     // spin forever to allow debugger to attach
   }
 }
 
-void usage() {
+static void usage() {
   //TODO:
 }
 
+static void on_fatal_error(const char *error) {
+  std::cerr << "Fatal error: " << error << std::endl;
+}
+
 void main(int argc, char **argv) {
   ignore_signal(SignalType::HangUp).ensure();
   ignore_signal(SignalType::Pipe).ensure();
   set_signal_handler(SignalType::Error, fail_signal).ensure();
   set_signal_handler(SignalType::Abort, fail_signal).ensure();
+  td::Log::set_fatal_error_callback(on_fatal_error);
 
   CliLog cli_log;
   log_interface = &cli_log;

td/telegram/td_log.cpp

@@ -8,6 +8,8 @@
 
 #include "td/telegram/Log.h"
 
+#include <cstdint>
+
 void td_set_log_file_path(const char *file_path) {
   td::Log::set_file_path(file_path == nullptr ? "" : file_path);
 }
@@ -19,3 +21,7 @@ void td_set_log_max_file_size(long long max_file_size) {
 void td_set_log_verbosity_level(int new_verbosity_level) {
   td::Log::set_verbosity_level(new_verbosity_level);
 }
+
+void td_set_log_fatal_error_callback(td_log_fatal_error_callback_ptr callback) {
+  td::Log::set_fatal_error_callback(callback);
+}

td/telegram/td_log.h

@@ -23,8 +23,8 @@ extern "C" {
  * By default TDLib writes logs to stderr or an OS specific log.
  * Use this method to write the log to a file instead.
  *
- * \param[in]  file_path Path to a file where the internal TDLib log will be written. Use an empty path to
- *                       switch back to the default logging behaviour.
+ * \param[in]  file_path Null-terminated path to a file where the internal TDLib log will be written.
+ *                       Use an empty path to switch back to the default logging behaviour.
  */
 TDJSON_EXPORT void td_set_log_file_path(const char *file_path);
 
@@ -52,6 +52,24 @@ TDJSON_EXPORT void td_set_log_max_file_size(long long max_file_size);
  */
 TDJSON_EXPORT void td_set_log_verbosity_level(int new_verbosity_level);
 
+/**
+ * A type of callback function that will be called when a fatal error happens.
+ *
+ * \param error_message Null-terminated string with a description of a happened fatal error.
+ */
+using td_log_fatal_error_callback_ptr = void (*)(const char *error_message);
+
+/**
+ * Sets the callback that will be called when a fatal error happens.
+ * None of the TDLib methods can be called from the callback.
+ * The TDLib will crash as soon as callback returns.
+ * By default the callback is not set.
+ *
+ * \param[in]  callback Callback that will be called when a fatal error happens.
+ *                      Pass NULL to remove the callback.
+ */
+TDJSON_EXPORT void td_set_log_fatal_error_callback(td_log_fatal_error_callback_ptr callback);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif

tdclientjson_export_list

@@ -6,3 +6,4 @@ _td_json_client_execute
 _td_set_log_file_path
 _td_set_log_max_file_size
 _td_set_log_verbosity_level
+_td_set_log_fatal_error_callback

tdutils/td/utils/FileLog.h

@@ -13,7 +13,6 @@
 #include "td/utils/port/path.h"
 #include "td/utils/Slice.h"
 
-#include <cstdlib>
 #include <limits>
 
 namespace td {
@@ -23,25 +22,25 @@ class FileLog : public LogInterface {
   static constexpr int DEFAULT_ROTATE_THRESHOLD = 10 * (1 << 20);
 
  public:
-  void append(CSlice xslice, int log_level) override {
-    Slice slice = xslice;
+  void append(CSlice cslice, int log_level) override {
+    Slice slice = cslice;
     while (!slice.empty()) {
       auto r_size = fd_.write(slice);
       if (r_size.is_error()) {
-        std::abort();
+        process_fatal_error(r_size.error().message());
       }
       auto written = r_size.ok();
       size_ += static_cast<int64>(written);
       slice.remove_prefix(written);
     }
     if (log_level == VERBOSITY_NAME(FATAL)) {
-      std::abort();
+      process_fatal_error(cslice);
     }
 
     if (size_ > rotate_threshold_) {
       auto status = rename(path_, path_ + ".old");
       if (status.is_error()) {
-        std::abort();
+        process_fatal_error(status.message());
       }
       do_rotate();
     }
@@ -83,7 +82,7 @@ class FileLog : public LogInterface {
     fd_.close();
     auto r_fd = FileFd::open(path_, FileFd::Create | FileFd::Truncate | FileFd::Write);
     if (r_fd.is_error()) {
-      std::abort();
+      process_fatal_error(r_fd.error().message());
     }
     fd_ = r_fd.move_as_ok();
     Fd::duplicate(fd_.get_fd(), Fd::Stderr()).ignore();

tdutils/td/utils/MemoryLog.h

@@ -57,6 +57,10 @@ class MemoryLog : public LogInterface {
     size_t printed = std::snprintf(&buffer_[start_pos + 1], magic_size - 1, "LOG:%08x: ", real_pos);
     CHECK(printed == magic_size - 2);
     buffer_[start_pos + magic_size - 1] = ' ';
+
+    if (log_level == VERBOSITY_NAME(FATAL)) {
+      process_fatal_error(new_slice);
+    }
   }
 
   void rotate() override {

tdutils/td/utils/logging.cpp

@@ -216,11 +216,7 @@ class DefaultLog : public LogInterface {
     TsCerr() << slice;
 #endif
     if (log_level == VERBOSITY_NAME(FATAL)) {
-      auto f = default_log_on_fatal_error;
-      if (f) {
-        f(slice);
-      }
-      std::abort();
+      process_fatal_error(slice);
     }
   }
   void rotate() override {
@@ -230,6 +226,19 @@ static DefaultLog default_log;
 
 LogInterface *const default_log_interface = &default_log;
 LogInterface *log_interface = default_log_interface;
-OnFatalErrorF default_log_on_fatal_error = nullptr;
+
+static OnFatalErrorCallback on_fatal_error_callback = nullptr;
+
+void set_log_fatal_error_callback(OnFatalErrorCallback callback) {
+  on_fatal_error_callback = callback;
+}
+
+void process_fatal_error(CSlice message) {
+  auto callback = on_fatal_error_callback;
+  if (callback) {
+    callback(message);
+  }
+  std::abort();
+}
 
 }  // namespace td

tdutils/td/utils/logging.h

@@ -30,7 +30,6 @@
 #include "td/utils/StringBuilder.h"
 
 #include <atomic>
-#include <cstdlib>
 #include <type_traits>
 
 #define PSTR_IMPL(...) ::td::Logger(::td::NullLog().ref(), 0, true).printf(__VA_ARGS__)
@@ -98,7 +97,7 @@ inline bool no_return_func() {
 
 #define UNREACHABLE(...)   \
   LOG(FATAL, __VA_ARGS__); \
-  std::abort()
+  ::td::process_fatal_error("Unreachable in " __FILE__ " at " TD_DEFINE_STR(__LINE__))
 
 constexpr int VERBOSITY_NAME(PLAIN) = -1;
 constexpr int VERBOSITY_NAME(FATAL) = 0;
@@ -148,8 +147,11 @@ class NullLog : public LogInterface {
 
 extern LogInterface *const default_log_interface;
 extern LogInterface *log_interface;
-typedef void (*OnFatalErrorF)(CSlice msg);
-extern OnFatalErrorF default_log_on_fatal_error;
+
+using OnFatalErrorCallback = void (*)(CSlice message);
+void set_log_fatal_error_callback(OnFatalErrorCallback callback);
+
+[[noreturn]] void process_fatal_error(CSlice message);
 
 #define TC_RED "\e[1;31m"
 #define TC_BLUE "\e[1;34m"