Many SDL subsystems depend on being able to see time passing. If you are porting to a new platform, you'll need to fill in a timer implementation as part of the initial port.
Fixes https://github.com/libsdl-org/SDL/issues/8850
- check libiconv with a linkage test with iconv.h included
- check libc iconv with a linkage test with iconv.h included
and LIBICONV_PLUG defined (in case libiconv header is in
include path)
- add new configuration option to prefer iconv from libiconv,
if available, over the libc version: SDL_LIBICONV, defaults
to disabled.
- remove FindIconv + pkg_check_modules for iconv, and use our
manual iconv finding only
- change FreeBSD specific LIBICONV_PLUG define in SDL_iconv.c
to configuration result.
Using /Zl, the obj files will no longer add a link requirement to the C
runtime libraries. Meanwhile, also add /NODEFAULTLIB for non-UWP MSVC
toolchains.
Because /Zl is a compile option, it can also be used when building a
static SDL3 library, and SDL3_test.
These were added a very long time ago and seem to serve no purpose now, as the functionality they provided is now in core Wayland protocols, current information on their usage and status is nonexistent, no modern compositor seems to support them, and the code paths are untested and subject to bit-rot at this point. It also causes duplicate symbol issues when statically linking an application to both Qt and SDL.
This lets apps optionally have a handful of callbacks for their entry points instead of a single main function. If used, the actual main/SDL_main/whatever entry point will be implemented in the single-header library SDL_main.h and the app will implement four separate functions:
First:
int SDL_AppInit(int argc, char **argv);
This will be called once before anything else. argc/argv work like they always do. If this returns 0, the app runs. If it returns < 0, the app calls SDL_AppQuit and terminates with an exit code that reports an error to the platform. If it returns > 0, the app calls SDL_AppQuit and terminates with an exit code that reports success to the platform. This function should not go into an infinite mainloop; it should do any one-time startup it requires and then return.
Then:
int SDL_AppIterate(void);
This is called over and over, possibly at the refresh rate of the display or some other metric that the platform dictates. This is where the heart of your app runs. It should return as quickly as reasonably possible, but it's not a "run one memcpy and that's all the time you have" sort of thing. The app should do any game updates, and render a frame of video. If it returns < 0, SDL will call SDL_AppQuit and terminate the process with an exit code that reports an error to the platform. If it returns > 0, the app calls SDL_AppQuit and terminates with an exit code that reports success to the platform. If it returns 0, then SDL_AppIterate will be called again at some regular frequency. The platform may choose to run this more or less (perhaps less in the background, etc), or it might just call this function in a loop as fast as possible. You do not check the event queue in this function (SDL_AppEvent exists for that).
Next:
int SDL_AppEvent(const SDL_Event *event);
This will be called once for each event pushed into the SDL queue. This may be called from any thread, and possibly in parallel to SDL_AppIterate. The fields in event do not need to be free'd (as you would normally need to do for SDL_EVENT_DROP_FILE, etc), and your app should not call SDL_PollEvent, SDL_PumpEvent, etc, as SDL will manage this for you. Return values are the same as from SDL_AppIterate(), so you can terminate in response to SDL_EVENT_QUIT, etc.
Finally:
void SDL_AppQuit(void);
This is called once before terminating the app--assuming the app isn't being forcibly killed or crashed--as a last chance to clean up. After this returns, SDL will call SDL_Quit so the app doesn't have to (but it's safe for the app to call it, too). Process termination proceeds as if the app returned normally from main(), so atexit handles will run, if your platform supports that.
The app does not implement SDL_main if using this. To turn this on, define SDL_MAIN_USE_CALLBACKS before including SDL_main.h. Defines like SDL_MAIN_HANDLED and SDL_MAIN_NOIMPL are also respected for callbacks, if the app wants to do some sort of magic main implementation thing.
In theory, on most platforms these can be implemented in the app itself, but this saves some #ifdefs in the app and lets everyone struggle less against some platforms, and might be more efficient in the long run, too.
On some platforms, it's possible this is the only reasonable way to go, but we haven't actually hit one that 100% requires it yet (but we will, if we want to write a RetroArch backend, for example).
Using the callback entry points works on every platform, because on platforms that don't require them, we can fake them with a simple loop in an internal implementation of the usual SDL_main.
The primary way we expect people to write SDL apps is with SDL_main, and this is not intended to replace it. If the app chooses to use this, it just removes some platform-specific details they might have to otherwise manage, and maybe removes a barrier to entry on some future platform.
Fixes#6785.
Reference PR #8247.
main features:
- No more sdl-build-options/sdl-shared-build-options/sdl-global-options
- Dependency information is stored on SDL3-collector for sdl3.pc
- Use helper functions to modify the SDL targets;
- sdl_sources to add sources
- sdl_glob_sources to add glob soruces
- sdl_link_dependency to add a link dependency that might also
appear in sdl3.pc/SDL3Config.cmake
- sdl_compile_definitions to add macro's
- sdl_compile_options for compile options
- sdl_include_directories for include directories
They avoid repeated checks for existence of the SDL targets
- A nice feature of the previous is the ability to generate
a sdl3.pc or SDL3Config.cmake that describes its dependencies
accurately.
various:
- remove duplicate libc symbol list
- add CheckVulkan
- remove unused HAVE_MPROTECT
- add checks for getpagesize
This fixes the following errors when a dll attempts to link to SDL3::SDL3-shared:
m.c.obj : error LNK2019: unresolved external symbol __imp___acrt_iob_func referenced in function printf
m.c.obj : error LNK2019: unresolved external symbol __imp___stdio_common_vfprintf referenced in function _vfprintf_l
MSVCRTD.lib(init.obj) : error LNK2019: unresolved external symbol _CrtDbgReport referenced in function _CRT_RTC_INIT
MSVCRTD.lib(init.obj) : error LNK2019: unresolved external symbol _CrtDbgReportW referenced in function _CRT_RTC_INITW
MSVCRTD.lib(error.obj) : error LNK2019: unresolved external symbol strcpy_s referenced in function "void __cdecl _RTC_StackFailure(void *,char const *)" (?_RTC_StackFailure@@YAXPEAXPEBD@Z)
MSVCRTD.lib(error.obj) : error LNK2019: unresolved external symbol strcat_s referenced in function "void __cdecl _RTC_StackFailure(void *,char const *)" (?_RTC_StackFailure@@YAXPEAXPEBD@Z)
MSVCRTD.lib(error.obj) : error LNK2019: unresolved external symbol __stdio_common_vsprintf_s referenced in function _vsprintf_s_l
MSVCRTD.lib(error.obj) : error LNK2001: unresolved external symbol __C_specific_handler_noexcept
MSVCRTD.lib(pdblkup.obj) : error LNK2019: unresolved external symbol _wmakepath_s referenced in function "int __cdecl GetPdbDllPathFromFilePath(wchar_t const *,wchar_t *,unsigned __int64)" (?GetPdbDllPathFromFilePath@@YAHPEB_WPEA_W_K@Z)
MSVCRTD.lib(pdblkup.obj) : error LNK2019: unresolved external symbol _wsplitpath_s referenced in function "int __cdecl GetPdbDllPathFromFilePath(wchar_t const *,wchar_t *,unsigned __int64)" (?GetPdbDllPathFromFilePath@@YAHPEB_WPEA_W_K@Z)
MSVCRTD.lib(pdblkup.obj) : error LNK2019: unresolved external symbol wcscpy_s referenced in function "int __cdecl GetPdbDllPathFromFilePath(wchar_t const *,wchar_t *,unsigned __int64)" (?GetPdbDllPathFromFilePath@@YAHPEB_WPEA_W_K@Z)
MSVCRTD.lib(pdblkup.obj) : error LNK2019: unresolved external symbol __vcrt_GetModuleFileNameW referenced in function "struct HINSTANCE__ * __cdecl GetPdbDll(void)" (?GetPdbDll@@YAPEAUHINSTANCE__@@XZ)
MSVCRTD.lib(pdblkup.obj) : error LNK2019: unresolved external symbol __vcrt_GetModuleHandleW referenced in function "struct HINSTANCE__ * __cdecl GetPdbDll(void)" (?GetPdbDll@@YAPEAUHINSTANCE__@@XZ)
MSVCRTD.lib(pdblkup.obj) : error LNK2019: unresolved external symbol __vcrt_LoadLibraryExW referenced in function "struct HINSTANCE__ * __cdecl GetPdbDll(void)" (?GetPdbDll@@YAPEAUHINSTANCE__@@XZ)
On platforms where time_t is a signed 32-bit integer, most notably i386 Linux,
various functions stop working when dealing with a timestamp
beyond January 2038.
glibc has an opt-in mechanism that redefines time_t to be 64-bit,
and correspondingly increases the size of all system data
structures that contain a time_t, such as struct timeval and struct stat.
This is necessary to allow timestamps beyond January 2038 to be represented;
as well as things that obviously deal with timestamps, this affects functions
like stat(), which will fail with EOVERFLOW if asked to inspect a file whose
correct timestamp does not fit in time_t. This in turn can cause unexpected
problems for "filesystem APIs" of the form "if /run/foo exists, then ..."
when accessed by 32-bit code, if the check for existence is done with stat()
rather than access().
Using 64-bit timestamps in glibc is an opt-in and not the default, because
if done carelessly it can change libraries' ABIs. However, SDL mostly doesn't
use system headers or types in its own headers. I
Co-authored-by: Simon McVittie <smcv@collabora.com>
Sam Lantinga