Merge #4729

4729: Add exception handling for Windows r=def- a=Jupeyy

Only tested on wine yet.

I am using https://github.com/jrfonseca/drmingw

We don't need to ship debug symbols, but need to keep a copy of DDNet.exe with debug symbols. Using addr2line works on the addresses printed by this tool.

currently crash reports go into %appdata%/Teeworlds/dumps (that dir seems to be rarely used anyway, but can also change to /crashlogs or smth)



## Checklist

- [ ] Tested the change ingame
- [ ] Provided screenshots if it is a visual change
- [ ] Tested in combination with possibly related configuration options
- [ ] Written a unit test if it works standalone, system.c especially
- [ ] Considered possible null pointers and out of bounds array indexing
- [ ] Changed no physics that affect existing maps
- [ ] Tested the change with [ASan+UBSan or valgrind's memcheck](https://github.com/ddnet/ddnet/#using-addresssanitizer--undefinedbehavioursanitizer-or-valgrinds-memcheck) (optional)


Co-authored-by: Jupeyy <jupjopjap@gmail.com>
Co-authored-by: Dennis Felsing <dennis@felsin9.de>

CMakeLists.txt

@@ -117,6 +117,8 @@ option(DISCORD_DYNAMIC "Enable discovering Discord rich presence libraries at ru
 option(PREFER_BUNDLED_LIBS "Prefer bundled libraries over system libraries" ${AUTO_DEPENDENCIES_DEFAULT})
 option(DEV "Don't generate stuff necessary for packaging" OFF)
 
+option(EXCEPTION_HANDLING "Enable exception handling (only works with Windows as of now)" OFF)
+
 if(TEST_MYSQL)
   set(MYSQL ON)
 endif()
@@ -217,6 +219,14 @@ if(NOT MSVC AND NOT HAIKU)
     add_c_compiler_flag_if_supported(OUR_FLAGS -stdlib=libc++)
   endif()
 
+  if(EXCEPTION_HANDLING)
+    add_c_compiler_flag_if_supported(OUR_FLAGS -DCONF_EXCEPTION_HANDLING)
+    # use the frame pointer (frame pointer usage is disabled by default in
+    # some architectures like x86_64 and for some optimization levels; and it
+    # may be impossible to walk the call stack without it)
+    add_c_compiler_flag_if_supported(OUR_FLAGS -fno-omit-frame-pointer)
+  endif()
+
   add_c_compiler_flag_if_supported(OUR_FLAGS_OWN -Wall)
   if(CMAKE_VERSION VERSION_GREATER 3.3 OR CMAKE_VERSION VERSION_EQUAL 3.3)
     add_c_compiler_flag_if_supported(OUR_FLAGS_OWN
@@ -239,6 +249,12 @@ if(NOT MSVC AND NOT HAIKU)
   #add_cxx_compiler_flag_if_supported(OUR_FLAGS_OWN "-Wuseless-cast")
 endif()
 
+if(MSVC)
+  if(EXCEPTION_HANDLING)
+  add_c_compiler_flag_if_supported(OUR_FLAGS /DCONF_EXCEPTION_HANDLING)
+  endif()
+endif()
+
 if(NOT MSVC AND NOT HAIKU)
   check_c_compiler_flag("-O2;-Wp,-Werror;-D_FORTIFY_SOURCE=2" DEFINE_FORTIFY_SOURCE) # Some distributions define _FORTIFY_SOURCE by themselves.
 endif()
@@ -440,6 +456,10 @@ else()
   set(WEBSOCKETS_INCLUDE_DIRS)
 endif()
 
+if(EXCEPTION_HANDLING)
+  find_package(ExceptionHandling)
+endif()
+
 if(TARGET_OS AND TARGET_OS STREQUAL "mac")
   find_program(CMAKE_OTOOL otool)
   find_program(DMGBUILD dmgbuild)
@@ -1399,6 +1419,7 @@ set(COPY_FILES
   ${FFMPEG_COPY_FILES}
   ${WEBSOCKETS_COPY_FILES}
   ${DISCORDSDK_COPY_FILES}
+  ${EXCEPTION_HANDLING_COPY_FILES}
 )
 file(COPY ${COPY_FILES} DESTINATION .)
 

cmake/FindExceptionHandling.cmake

@@ -0,0 +1,21 @@
+if(TARGET_OS STREQUAL "windows")
+  set_extra_dirs_lib(EXCEPTION_HANDLING drmingw)
+  find_file(EXCEPTION_HANDLING_LIBRARY
+    NAMES exchndl.dll
+    HINTS ${HINTS_EXCEPTION_HANDLING_LIBDIR}
+    PATHS ${PATHS_EXCEPTION_HANDLING_LIBDIR}
+    ${CROSSCOMPILING_NO_CMAKE_SYSTEM_PATH}
+  )
+
+  is_bundled(EXCEPTION_HANDLING_BUNDLED "${EXCEPTION_HANDLING_LIBRARY}")
+  if(NOT EXCEPTION_HANDLING_BUNDLED)
+    message(FATAL_ERROR "could not find exception handling paths")
+  endif()
+  set(EXCEPTION_HANDLING_COPY_FILES 
+    "${EXTRA_EXCEPTION_HANDLING_LIBDIR}/exchndl.dll"
+    "${EXTRA_EXCEPTION_HANDLING_LIBDIR}/dbgcore.dll"
+    "${EXTRA_EXCEPTION_HANDLING_LIBDIR}/dbghelp.dll"
+    "${EXTRA_EXCEPTION_HANDLING_LIBDIR}/mgwhelp.dll"
+    "${EXTRA_EXCEPTION_HANDLING_LIBDIR}/symsrv.dll"
+  )
+endif()

ddnet-libs

@@ -1 +1 @@
-Subproject commit 1cdf759f4e46edbe174250f523b9cc737c4ad8ea
+Subproject commit 635aa7afb698ed68feeb733aaea2cf861c2a1899

src/base/system.cpp

@@ -4060,4 +4060,45 @@ int os_version_str(char *version, int length)
 	return 0;
 #endif
 }
+
+#if defined(CONF_EXCEPTION_HANDLING)
+#if defined(CONF_FAMILY_WINDOWS)
+static HMODULE gs_ExceptionHandlingModule = nullptr;
+#endif
+
+void init_exception_handler()
+{
+#if defined(CONF_FAMILY_WINDOWS)
+	gs_ExceptionHandlingModule = LoadLibraryA("exchndl.dll");
+	if(gs_ExceptionHandlingModule != nullptr)
+	{
+		auto pfnExcHndlInit = (void APIENTRY (*)())GetProcAddress(gs_ExceptionHandlingModule, "ExcHndlInit");
+		pfnExcHndlInit();
+	}
+#else
+#error exception handling not implemented
+#endif
+}
+
+void set_exception_handler_log_file(const char *pLogFilePath)
+{
+#if defined(CONF_FAMILY_WINDOWS)
+	if(gs_ExceptionHandlingModule != nullptr)
+	{
+		// Intentional
+#ifdef __MINGW32__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wcast-function-type"
+#endif
+		auto pExceptionLogFilePathFunc = (BOOL APIENTRY(*)(const char *))(GetProcAddress(gs_ExceptionHandlingModule, "ExcHndlSetLogFileNameA"));
+#ifdef __MINGW32__
+#pragma clang diagnostic pop
+#endif
+		pExceptionLogFilePathFunc(pLogFilePath);
+	}
+#else
+#error exception handling not implemented
+#endif
+}
+#endif
 }

src/base/system.h

@@ -2368,6 +2368,11 @@ void set_console_msg_color(const void *rgbvoid);
 */
 int os_version_str(char *version, int length);
 
+#if defined(CONF_EXCEPTION_HANDLING)
+void init_exception_handler();
+void set_exception_handler_log_file(const char *pLogFilePath);
+#endif
+
 #if defined(__cplusplus)
 }
 #endif

src/engine/client/client.cpp

@@ -4268,6 +4268,10 @@ int main(int argc, const char **argv)
 	InitAndroid();
 #endif
 
+#if defined(CONF_EXCEPTION_HANDLING)
+	init_exception_handler();
+#endif
+
 	if(secure_random_init() != 0)
 	{
 		RandInitFailed = true;
@@ -4292,6 +4296,16 @@ int main(int argc, const char **argv)
 	IDiscord *pDiscord = CreateDiscord();
 	ISteam *pSteam = CreateSteam();
 
+#if defined(CONF_EXCEPTION_HANDLING)
+	char aBuf[IO_MAX_PATH_LENGTH];
+	char aBufName[IO_MAX_PATH_LENGTH];
+	char aDate[64];
+	str_timestamp(aDate, sizeof(aDate));
+	str_format(aBufName, sizeof(aBufName), "dumps/" GAME_NAME "_crash_log_%d_%s.RTP", pid(), aDate);
+	pStorage->GetCompletePath(IStorage::TYPE_SAVE, aBufName, aBuf, sizeof(aBuf));
+	set_exception_handler_log_file(aBuf);
+#endif
+
 	if(RandInitFailed)
 	{
 		dbg_msg("secure", "could not initialize secure RNG");

src/engine/server/server.cpp

@@ -3645,6 +3645,10 @@ int main(int argc, const char **argv)
 	signal(SIGINT, HandleSigIntTerm);
 	signal(SIGTERM, HandleSigIntTerm);
 
+#if defined(CONF_EXCEPTION_HANDLING)
+	init_exception_handler();
+#endif
+
 	CServer *pServer = CreateServer();
 	IKernel *pKernel = IKernel::Create();
 
@@ -3658,6 +3662,16 @@ int main(int argc, const char **argv)
 	IConfigManager *pConfigManager = CreateConfigManager();
 	IEngineAntibot *pEngineAntibot = CreateEngineAntibot();
 
+#if defined(CONF_EXCEPTION_HANDLING)
+	char aBuf[IO_MAX_PATH_LENGTH];
+	char aBufName[IO_MAX_PATH_LENGTH];
+	char aDate[64];
+	str_timestamp(aDate, sizeof(aDate));
+	str_format(aBufName, sizeof(aBufName), "dumps/" GAME_NAME "-Server_crash_log_%d_%s.RTP", pid(), aDate);
+	pStorage->GetCompletePath(IStorage::TYPE_SAVE, aBufName, aBuf, sizeof(aBuf));
+	set_exception_handler_log_file(aBuf);
+#endif
+
 	pServer->InitRegister(&pServer->m_NetServer, pEngineMasterServer, pConfigManager->Values(), pConsole);
 
 	{