We can also ditch the lock in RAWINPUT_JoystickQuit() now that the joystick
subsystem quits drivers in reverse order. There's no chance of a racing call
to RAWINPUT_WindowProc() anymore.
SDL_WINDOWS_JoystickDriver depends on callbacks in SDL_RAWINPUT_JoystickDriver
and SDL_HIDAPI_JoystickDriver being available. It also manages the common
WindowProc used for joystick detection in both WINDOWS and RAWINPUT drivers.
If we don't tear them down backwards, there's a window of time where we could
invoke RAWINPUT_WindowProc() after RAWINPUT_JoystickQuit() was called.
Since accessing Bluetooth prompts the user for permission on both Android and iOS, and we only need it for Steam Controller support, we'll leave it off by default. You can enable it by setting the hint SDL_HINT_JOYSTICK_HIDAPI_STEAM to "1" before calling SDL_Init()
Fixes https://github.com/libsdl-org/SDL/issues/4952
macOS 10.6 has some touch NSEvents which do not have a subtype
(Begin/EndGesture, Magnify, Rotate, Swipe) and cause an uncaught
exception which triggers SIGABRT and the program exits.
As it is, none of the macOS 10.6 touch events are detected as a
trackpad (including Gesture due to using different subtypes).
Case fallthrough warnings can be suppressed using the __fallthrough__
compiler attribute. Unfortunately, not all compilers have this
attribute, or even have __has_attribute to check if they have the
__fallthrough__ attribute. [[fallthrough]] is also available in C++17
and the next C2x, but not everyone uses C++17 or C2x.
So define the SDL_FALLTHROUGH macro to deal with those problems - if we
are using C++17 or C2x, it expands to [[fallthrough]]; else if the
compiler has __has_attribute and has the __fallthrough__ attribute, then
it expands to __attribute__((__fallthrough__)); else it expands to an
empty statement, with a /* fallthrough */ comment (it's a do {} while
(0) statement, because users of this macro need to use a semicolon,
because [[fallthrough]] and __attribute__((__fallthrough__)) require a
semicolon).
Clang before Clang 10 and GCC before GCC 7 have problems with using
__attribute__ as a sole statement and warn about a "declaration not
declaring anything", so fall back to using the /* fallthrough */ comment
if we are using those older compiler versions.
Applications using SDL are also free to use this macro (because it is
defined in begin_code.h).
All existing /* fallthrough */ comments have been replaced with this
macro. Some of them were unnecessary because they were the last case in
a switch; using SDL_FALLTHROUGH in those cases would result in a compile
error on compilers that support __fallthrough__, for having a
__attribute__((__fallthrough__)) statement that didn't immediately
precede a case label.