SDL: cmake: Detect SDL_JOYSTICK_MFI for macOS

From bc409163a81e5f440399926774202dd2da3e37c3 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <[EMAIL REDACTED]>
Date: Sat, 20 Nov 2021 17:05:28 -0600
Subject: [PATCH] cmake: Detect SDL_JOYSTICK_MFI for macOS

---
 CMakeLists.txt | 33 +++++++++++++++++++++++++++++----
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8a755c6bde..20a743a907 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1825,8 +1825,9 @@ elseif(APPLE)
   endif()
 
   if(SDL_JOYSTICK)
+    file(GLOB MFI_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/iphoneos/*.m)
     if(IOS OR TVOS)
-      file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/iphoneos/*.m ${SDL2_SOURCE_DIR}/src/joystick/steam/*.c)
+      file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/steam/*.c)
       set(SDL_JOYSTICK_MFI 1)
       if(IOS)
         set(SDL_FRAMEWORK_COREMOTION 1)
@@ -1835,13 +1836,37 @@ elseif(APPLE)
       set(SDL_FRAMEWORK_COREHAPTICS 1)
       set(HAVE_SDL_SENSORS 1)
     else()
-      file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/darwin/*.c ${SDL2_SOURCE_DIR}/src/joystick/iphoneos/*.m)
-      # FIXME: add checks for SDL_JOYSTICK_MFI???
+      file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/darwin/*.c)
+      set_source_files_properties(${MFI_JOYSTICK_SOURCES} PROPERTIES COMPILE_FLAGS -fobjc-weak)
+      check_objc_source_compiles("
+          #include <AvailabilityMacros.h>
+          #include <TargetConditionals.h>
+          #import <Foundation/Foundation.h>
+          #import <GameController/GameController.h>
+          #if MAC_OS_X_VERSION_MIN_REQUIRED < 1080
+          #error GameController framework doesn't work on this configuration
+          #endif
+          #if TARGET_CPU_X86
+          #error GameController framework doesn't work on this configuration
+          #endif
+          int main() {}" HAVE_FRAMEWORK_GAMECONTROLLER)
+      check_objc_source_compiles("
+          #include <AvailabilityMacros.h>
+          #include <TargetConditionals.h>
+          #import <Foundation/Foundation.h>
+          #import <CoreHaptics/CoreHaptics.h>
+          int main() {}" HAVE_FRAMEWORK_COREHAPTICS)
+      if(HAVE_FRAMEWORK_GAMECONTROLLER AND HAVE_FRAMEWORK_COREHAPTICS)
+        # Only enable MFI if we also have CoreHaptics to ensure rumble works
+        set(SDL_JOYSTICK_MFI 1)
+        set(SDL_FRAMEWORK_GAMECONTROLLER 1)
+        set(SDL_FRAMEWORK_COREHAPTICS 1)
+      endif()
       set(SDL_JOYSTICK_IOKIT 1)
       set(SDL_FRAMEWORK_IOKIT 1)
       set(SDL_FRAMEWORK_FF 1)
     endif()
-    set(SOURCE_FILES ${SOURCE_FILES} ${JOYSTICK_SOURCES})
+    set(SOURCE_FILES ${SOURCE_FILES} ${JOYSTICK_SOURCES} ${MFI_JOYSTICK_SOURCES})
     set(HAVE_SDL_JOYSTICK TRUE)
   endif()