libobs: Use static library for version string information

Switching to a static library that contains version information as
const char strings has multiple benefits:

* The version information provided externally via compiler definitions
  will fail compilation early if malformed
* An updated version string (which will happen with every commit) will
  not invalidate existing compilation units, because only the static
  library is affected by the change
* An update of the version change just requires a recompilation of the
  static library and a linker update
* An update of the version will _not_ infect the rest of the codebase
  (as it does currently, because everything includes obsconfig.h one
  way or another)
* Other modules which used the macro definition directly have been
  updated as much as possible to use the proper getter method from
  `libobs` instead (some Windows-specific modules use preprocessor
  string composition, the value has been added as a compiler definition
  directly in those cases)
* Because the impact of a version change due to a commit hash change
  is limited to the static library, ccache hit rates should be
  improved considerably

UI/cmake/legacy.cmake

@@ -370,6 +370,7 @@ if(OS_WINDOWS)
   target_compile_definitions(obs PRIVATE UNICODE _UNICODE _CRT_SECURE_NO_WARNINGS _CRT_NONSTDC_NO_WARNINGS
                                          PSAPI_VERSION=2)
 
+  set_source_files_properties(update/win-update.cpp PROPERTIES COMPILE_DEFINITIONS OBS_COMMIT="${OBS_COMMIT}")
   if(MSVC)
     target_link_options(obs PRIVATE "LINKER:/IGNORE:4098" "LINKER:/IGNORE:4099")
     target_link_libraries(obs PRIVATE OBS::w32-pthreads)

UI/cmake/os-windows.cmake

@@ -37,6 +37,7 @@ add_library(OBS::update-helpers ALIAS obs-update-helpers)
 
 target_sources(obs-update-helpers INTERFACE win-update/win-update-helpers.cpp win-update/win-update-helpers.hpp)
 target_include_directories(obs-update-helpers INTERFACE "${CMAKE_CURRENT_SOURCE_DIR}/win-update")
+set_source_files_properties(update/win-update.cpp PROPERTIES COMPILE_DEFINITIONS OBS_COMMIT="${OBS_COMMIT}")
 
 add_subdirectory(win-update/updater)
 

UI/obs-app.cpp

@@ -1743,7 +1743,7 @@ string OBSApp::GetVersionString(bool platform) const
 	stringstream ver;
 
 #ifdef HAVE_OBSCONFIG_H
-	ver << OBS_VERSION;
+	ver << obs_get_version_string();
 #else
 	ver << LIBOBS_API_MAJOR_VER << "." << LIBOBS_API_MINOR_VER << "."
 	    << LIBOBS_API_PATCH_VER;

UI/window-basic-about.cpp

@@ -24,7 +24,7 @@ OBSAbout::OBSAbout(QWidget *parent) : QDialog(parent), ui(new Ui::OBSAbout)
 		bitness = " (64 bit)";
 
 #ifdef HAVE_OBSCONFIG_H
-	ver += OBS_VERSION;
+	ver += obs_get_version_string();
 #else
 	ver += LIBOBS_API_MAJOR_VER + "." + LIBOBS_API_MINOR_VER + "." +
 	       LIBOBS_API_PATCH_VER;

libobs/CMakeLists.txt

@@ -2,6 +2,14 @@ cmake_minimum_required(VERSION 3.16...3.25)
 
 legacy_check()
 
+# cmake-format: off
+add_library(libobs-version STATIC EXCLUDE_FROM_ALL)
+add_library(OBS::libobs-version ALIAS libobs-version)
+# cmake-format: on
+configure_file(obsversion.c.in obsversion.c @ONLY)
+target_sources(libobs-version PRIVATE obsversion.c obsversion.h)
+set_property(TARGET libobs-version PROPERTY FOLDER core)
+
 add_library(libobs SHARED)
 add_library(OBS::libobs ALIAS libobs)
 
@@ -226,6 +234,7 @@ target_link_libraries(
   libobs
   PRIVATE OBS::caption
           OBS::uthash
+          OBS::libobs-version
           FFmpeg::avcodec
           FFmpeg::avformat
           FFmpeg::avutil

libobs/cmake/legacy.cmake

@@ -4,6 +4,15 @@ endif()
 
 project(libobs)
 
+# cmake-format: off
+add_library(libobs-version STATIC EXCLUDE_FROM_ALL)
+add_library(OBS::libobs-version ALIAS libobs-version)
+# cmake-format: on
+configure_file(obsversion.c.in obsversion.c @ONLY)
+target_sources(libobs-version PRIVATE obsversion.c obsversion.h)
+target_include_directories(libobs-version PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
+set_property(TARGET libobs-version PROPERTY FOLDER core)
+
 find_package(Threads REQUIRED)
 find_package(
   FFmpeg REQUIRED
@@ -249,6 +258,7 @@ target_link_libraries(
           Jansson::Jansson
           OBS::caption
           OBS::uthash
+          OBS::libobs-version
           ZLIB::ZLIB
   PUBLIC Threads::Threads)
 
@@ -304,7 +314,8 @@ if(OS_WINDOWS)
             audio-monitoring/win32/wasapi-monitoring-available.c)
 
   target_compile_definitions(libobs PRIVATE UNICODE _UNICODE _CRT_SECURE_NO_WARNINGS _CRT_NONSTDC_NO_WARNINGS)
-
+  set_source_files_properties(obs-win-crash-handler.c PROPERTIES COMPILE_DEFINITIONS
+                                                                 OBS_VERSION="${OBS_VERSION_CANONICAL}")
   target_link_libraries(libobs PRIVATE dxgi Avrt Dwmapi winmm Rpcrt4)
 
   if(MSVC)

libobs/cmake/os-windows.cmake

@@ -40,6 +40,8 @@ target_sources(
           util/windows/window-helpers.h)
 
 target_compile_options(libobs PRIVATE $<$<COMPILE_LANGUAGE:C,CXX>:/EHc->)
+set_source_files_properties(obs-win-crash-handler.c PROPERTIES COMPILE_DEFINITIONS
+                                                               OBS_VERSION="${OBS_VERSION_CANONICAL}")
 
 target_link_libraries(
   libobs

libobs/obs-internal.h

@@ -38,6 +38,7 @@
 
 #include "obs.h"
 
+#include <obsversion.h>
 #include <caption/caption.h>
 
 /* Custom helpers for the UUID hash table */

libobs/obsconfig.h.in

@@ -1,13 +1,9 @@
 #pragma once
 
-#define OBS_VERSION "@OBS_VERSION@"
-
-#cmakedefine OBS_VERSION_CANONICAL "@OBS_VERSION_CANONICAL@"
 #cmakedefine OBS_DATA_PATH "@OBS_DATA_PATH@"
 #cmakedefine OBS_PLUGIN_PATH "@OBS_PLUGIN_PATH@"
 #cmakedefine OBS_PLUGIN_DESTINATION "@OBS_PLUGIN_DESTINATION@"
 
-#cmakedefine OBS_COMMIT "@OBS_COMMIT@"
 #cmakedefine GIO_FOUND
 #cmakedefine PULSEAUDIO_FOUND
 #cmakedefine XCB_XINPUT_FOUND

libobs/obsversion.c.in

@@ -0,0 +1,5 @@
+#include <obsversion.h>
+
+const char *OBS_VERSION = "@OBS_VERSION@";
+const char *OBS_VERSION_CANONICAL = "@OBS_VERSION_CANONICAL@";
+const char *OBS_COMMIT = "@OBS_COMMIT@";

libobs/obsversion.h

@@ -0,0 +1,5 @@
+#pragma once
+
+extern const char *OBS_VERSION;
+extern const char *OBS_VERSION_CANONICAL;
+extern const char *OBS_COMMIT;

plugins/obs-ffmpeg/obs-ffmpeg-hls-mux.c

@@ -136,7 +136,7 @@ bool ffmpeg_hls_mux_start(void *data)
 	dstr_copy(&stream->muxer_settings,
 		  "method=PUT http_persistent=1 ignore_io_errors=1 ");
 	dstr_catf(&stream->muxer_settings, "http_user_agent=libobs/%s",
-		  OBS_VERSION);
+		  obs_get_version_string());
 
 	vencoder = obs_output_get_video_encoder(stream->output);
 	settings = obs_encoder_get_settings(vencoder);

plugins/obs-outputs/flv-mux.c

@@ -167,7 +167,7 @@ static void build_flv_meta_data(obs_output_t *context, uint8_t **output,
 	dstr_printf(&encoder_name, "%s (libobs version ", MODULE_NAME);
 
 #ifdef HAVE_OBSCONFIG_H
-	dstr_cat(&encoder_name, OBS_VERSION);
+	dstr_cat(&encoder_name, obs_get_version_string());
 #else
 	dstr_catf(&encoder_name, "%d.%d.%d", LIBOBS_API_MAJOR_VER,
 		  LIBOBS_API_MINOR_VER, LIBOBS_API_PATCH_VER);

plugins/obs-outputs/ftl-stream.c

@@ -1074,7 +1074,7 @@ static int init_connect(struct ftl_stream *stream)
 	stream->params.audio_codec = FTL_AUDIO_OPUS;
 	stream->params.ingest_hostname = stream->path.array;
 	stream->params.vendor_name = "OBS Studio";
-	stream->params.vendor_version = OBS_VERSION;
+	stream->params.vendor_version = obs_get_version_string();
 	stream->params.peak_kbps = stream->peak_kbps < 0 ? 0
 							 : stream->peak_kbps;
 

plugins/win-capture/CMakeLists.txt

@@ -51,7 +51,8 @@ if(MSVC)
   target_link_options(win-capture PRIVATE "LINKER:/IGNORE:4098")
 endif()
 
-target_compile_definitions(win-capture PRIVATE UNICODE _UNICODE _CRT_SECURE_NO_WARNINGS _CRT_NONSTDC_NO_WARNINGS)
+target_compile_definitions(win-capture PRIVATE UNICODE _UNICODE _CRT_SECURE_NO_WARNINGS _CRT_NONSTDC_NO_WARNINGS
+                                               OBS_VERSION="${OBS_VERSION_CANONICAL}")
 
 set_property(GLOBAL APPEND PROPERTY OBS_MODULE_LIST "win-capture")