CMake: iOS support added

When using a recent version of CMake (3.14+), this should make it possible to:
- build SDL for iOS, both static and dynamic
- build SDL test apps (as iOS .app bundles)
- generate a working SDL_config.h for iOS (using SDL_config.h.cmake as a basis)

To use, set the following CMake variables when running CMake's configuration stage:
- CMAKE_SYSTEM_NAME=iOS
- CMAKE_OSX_SYSROOT=<SDK>  (examples: iphoneos, iphonesimulator, iphoneos12.4, /full/path/to/iPhoneOS.sdk, etc.)
- CMAKE_OSX_ARCHITECTURES=<semicolon-separated list of CPU architectures> (example: "arm64;armv7s")

Examples:
- for Simulator, using the latest, installed SDK:
    cmake path/to/SDL -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphonesimulator -DCMAKE_OSX_ARCHITECTURES=x86_64

- for Device, using the latest, installed SDK, 64-bit only
    cmake path/to/SDL -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos -DCMAKE_OSX_ARCHITECTURES=arm64

- for Device, using the latest, installed SDK, mixed 32/64 bit
    cmake path/to/SDL -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos -DCMAKE_OSX_ARCHITECTURES="arm64;armv7s"

- for Device, using a specific SDK revision (iOS 12.4, in this example):
    cmake path/to/SDL -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos12.4 -DCMAKE_OSX_ARCHITECTURES=arm64

- for Simulator, using the latest, installed SDK, and building SDL test apps (as .app bundles):
    cmake path/to/SDL -DSDL_TEST=1 -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphonesimulator -DCMAKE_OSX_ARCHITECTURES=x86_64

CMakeLists.txt

@@ -1453,6 +1453,7 @@ elseif(APPLE)
     set(SDL_FRAMEWORK_COCOA 1)
     set(SDL_FRAMEWORK_CARBON 1)
   endif()
+  set(SDL_FRAMEWORK_FOUNDATION 1)
 
   # Requires the darwin file implementation
   if(SDL_FILE)
@@ -1476,6 +1477,7 @@ elseif(APPLE)
     set(HAVE_SDL_AUDIO TRUE)
     set(SDL_FRAMEWORK_COREAUDIO 1)
     set(SDL_FRAMEWORK_AUDIOTOOLBOX 1)
+    set(SDL_FRAMEWORK_AVFOUNDATION 1)
   endif()
 
   if(SDL_JOYSTICK)
@@ -1483,43 +1485,49 @@ elseif(APPLE)
     if(HAVE_HIDAPI)
       if(IOS)
         set(SOURCE_FILES ${SOURCE_FILES} ${SDL2_SOURCE_DIR}/src/hidapi/ios/hid.m)
+        set(SDL_FRAMEWORK_COREBLUETOOTH 1)
       endif()
     endif()
-    set(SDL_JOYSTICK_IOKIT 1)
     if (IOS)
       file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/iphoneos/*.m ${SDL2_SOURCE_DIR}/src/joystick/steam/*.c)
+      set(SDL_JOYSTICK_MFI 1)
+      set(SDL_FRAMEWORK_COREMOTION 1)
+      set(SDL_FRAMEWORK_GAMECONTROLLER 1)
+      set(HAVE_SDL_SENSORS 1)
     else()
       file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/darwin/*.c)
+      set(SDL_JOYSTICK_IOKIT 1)
+      set(SDL_FRAMEWORK_IOKIT 1)
+      set(SDL_FRAMEWORK_FF 1)
     endif()
     set(SOURCE_FILES ${SOURCE_FILES} ${JOYSTICK_SOURCES})
     set(HAVE_SDL_JOYSTICK TRUE)
-    set(SDL_FRAMEWORK_IOKIT 1)
-    set(SDL_FRAMEWORK_FF 1)
   endif()
 
   if(SDL_HAPTIC)
-    set(SDL_HAPTIC_IOKIT 1)
     if (IOS)
       file(GLOB HAPTIC_SOURCES ${SDL2_SOURCE_DIR}/src/haptic/dummy/*.c)
       set(SDL_HAPTIC_DUMMY 1)
     else()
       file(GLOB HAPTIC_SOURCES ${SDL2_SOURCE_DIR}/src/haptic/darwin/*.c)
+      set(SDL_HAPTIC_IOKIT 1)
+      set(SDL_FRAMEWORK_IOKIT 1)
+      set(SDL_FRAMEWORK_FF 1)
     endif()
     set(SOURCE_FILES ${SOURCE_FILES} ${HAPTIC_SOURCES})
     set(HAVE_SDL_HAPTIC TRUE)
-    set(SDL_FRAMEWORK_IOKIT 1)
-    set(SDL_FRAMEWORK_FF 1)
     if(NOT SDL_JOYSTICK)
       message(FATAL_ERROR "SDL_HAPTIC requires SDL_JOYSTICK to be enabled")
     endif()
   endif()
 
   if(SDL_POWER)
-    set(SDL_POWER_MACOSX 1)
     if (IOS)
       file(GLOB POWER_SOURCES ${SDL2_SOURCE_DIR}/src/power/uikit/*.m)
+      set(SDL_POWER_UIKIT 1)
     else()
       file(GLOB POWER_SOURCES ${SDL2_SOURCE_DIR}/src/power/macosx/*.c)
+      set(SDL_POWER_MACOSX 1)
     endif()
     set(SOURCE_FILES ${SOURCE_FILES} ${POWER_SOURCES})
     set(HAVE_SDL_POWER TRUE)
@@ -1542,10 +1550,24 @@ elseif(APPLE)
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
 
+  if(SDL_SENSOR)
+    if(IOS)
+      set(SDL_SENSOR_COREMOTION 1)
+      set(HAVE_SDL_SENSORS TRUE)
+      file(GLOB SENSOR_SOURCES ${SDL2_SOURCE_DIR}/src/sensor/coremotion/*.m)
+      set(SOURCE_FILES ${SOURCE_FILES} ${SENSOR_SOURCES})
+    endif()
+  endif()
+
   # iOS hack needed - http://code.google.com/p/ios-cmake/ ?
   if(SDL_VIDEO)
     if (IOS)
       set(SDL_VIDEO_DRIVER_UIKIT 1)
+      set(SDL_FRAMEWORK_COREGRAPHICS 1)
+      set(SDL_FRAMEWORK_QUARTZCORE 1)
+      set(SDL_FRAMEWORK_UIKIT 1)
+      set(SDL_IPHONE_KEYBOARD 1)
+      set(SDL_IPHONE_LAUNCHSCREEN 1)
       file(GLOB UIKITVIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/uikit/*.m)
       set(SOURCE_FILES ${SOURCE_FILES} ${UIKITVIDEO_SOURCES})
     else()
@@ -1556,15 +1578,21 @@ elseif(APPLE)
         set(SDL_VIDEO_RENDER_OGL 1)
         set(HAVE_VIDEO_OPENGL TRUE)
       endif()
+    endif()
 
-      if(VIDEO_OPENGLES)
+    if(VIDEO_OPENGLES)
+      if(IOS)
+        set(SDL_FRAMEWORK_OPENGLES 1)
+        set(SDL_VIDEO_OPENGL_ES 1)
+        set(SDL_VIDEO_RENDER_OGL_ES 1)
+      else()
         set(SDL_VIDEO_OPENGL_EGL 1)
-        set(SDL_VIDEO_OPENGL_ES2 1)
-        set(SDL_VIDEO_RENDER_OGL_ES2 1)
-        set(HAVE_VIDEO_OPENGLES TRUE)
       endif()
+      set(SDL_VIDEO_OPENGL_ES2 1)
+      set(SDL_VIDEO_RENDER_OGL_ES2 1)
+      set(HAVE_VIDEO_OPENGLES TRUE)
     endif()
-    
+
     if(VIDEO_VULKAN OR VIDEO_METAL OR RENDER_METAL)
       set(ORIG_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
       set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -x objective-c")
@@ -1634,6 +1662,30 @@ elseif(APPLE)
     find_library(AUDIOTOOLBOX AudioToolbox)
     list(APPEND EXTRA_LIBS ${AUDIOTOOLBOX})
   endif()
+  if(SDL_FRAMEWORK_AVFOUNDATION)
+    find_library(AVFOUNDATION AVFoundation)
+    list(APPEND EXTRA_LIBS ${AVFOUNDATION})
+  endif()
+  if(SDL_FRAMEWORK_COREBLUETOOTH)
+    find_library(COREBLUETOOTH CoreBluetooth)
+    list(APPEND EXTRA_LIBS ${COREBLUETOOTH})
+  endif()
+  if(SDL_FRAMEWORK_COREGRAPHICS)
+    find_library(COREGRAPHICS CoreGraphics)
+    list(APPEND EXTRA_LIBS ${COREGRAPHICS})
+  endif()
+  if(SDL_FRAMEWORK_COREMOTION)
+    find_library(COREMOTION CoreMotion)
+    list(APPEND EXTRA_LIBS ${COREMOTION})
+  endif()
+  if(SDL_FRAMEWORK_FOUNDATION)
+    find_library(FOUNDATION Foundation)
+    list(APPEND EXTRA_LIBS ${FOUNDATION})
+  endif()
+  if(SDL_FRAMEWORK_GAMECONTROLLER)
+    find_library(GAMECONTROLLER GameController)
+    list(APPEND EXTRA_LIBS ${GAMECONTROLLER})
+  endif()
   if(SDL_FRAMEWORK_METAL)
     if(IOS)
       find_library(METAL Metal)
@@ -1642,6 +1694,10 @@ elseif(APPLE)
       list(APPEND EXTRA_LDFLAGS "-Wl,-weak_framework,Metal")
     endif()
   endif()
+  if(SDL_FRAMEWORK_OPENGLES)
+    find_library(OPENGLES OpenGLES)
+    list(APPEND EXTRA_LIBS ${OPENGLES})
+  endif()
   if(SDL_FRAMEWORK_QUARTZCORE)
     if(IOS)
       find_library(QUARTZCORE QuartzCore)
@@ -1650,6 +1706,10 @@ elseif(APPLE)
       list(APPEND EXTRA_LDFLAGS "-Wl,-weak_framework,QuartzCore")
     endif()
   endif()
+  if(SDL_FRAMEWORK_UIKIT)
+    find_library(UIKIT UIKit)
+    list(APPEND EXTRA_LIBS ${UIKIT})
+  endif()
 
   CheckPTHREAD()
 
@@ -1900,6 +1960,10 @@ if(SDL_SHARED)
   if (NOT ANDROID)
     set_target_properties(SDL2 PROPERTIES DEBUG_POSTFIX ${SDL_CMAKE_DEBUG_POSTFIX})
   endif()
+  if(IOS)
+    set_property(TARGET SDL2 APPEND_STRING PROPERTY COMPILE_FLAGS "-fobjc-arc")
+    target_compile_definitions(SDL2 PRIVATE IOS_DYLIB=1)
+  endif()
 endif()
 
 if(ANDROID)
@@ -1942,6 +2006,9 @@ if(SDL_STATIC)
   if (NOT ANDROID)
     set_target_properties(SDL2-static PROPERTIES DEBUG_POSTFIX ${SDL_CMAKE_DEBUG_POSTFIX})
   endif()
+  if(IOS)
+    set_property(TARGET SDL2-static APPEND_STRING PROPERTY COMPILE_FLAGS "-fobjc-arc")
+  endif()
 endif()
 
 ##### Tests #####

include/SDL_config.h.cmake

@@ -298,6 +298,7 @@
 
 /* Enable various sensor drivers */
 #cmakedefine SDL_SENSOR_ANDROID @SDL_SENSOR_ANDROID@
+#cmakedefine SDL_SENSOR_COREMOTION @SDL_SENSOR_COREMOTION@
 #cmakedefine SDL_SENSOR_DUMMY @SDL_SENSOR_DUMMY@
 
 /* Enable various shared object loading systems */
@@ -323,6 +324,7 @@
 #cmakedefine SDL_VIDEO_DRIVER_ANDROID @SDL_VIDEO_DRIVER_ANDROID@
 #cmakedefine SDL_VIDEO_DRIVER_HAIKU @SDL_VIDEO_DRIVER_HAIKU@
 #cmakedefine SDL_VIDEO_DRIVER_COCOA @SDL_VIDEO_DRIVER_COCOA@
+#cmakedefine SDL_VIDEO_DRIVER_UIKIT @SDL_VIDEO_DRIVER_UIKIT@
 #cmakedefine SDL_VIDEO_DRIVER_DIRECTFB @SDL_VIDEO_DRIVER_DIRECTFB@
 #cmakedefine SDL_VIDEO_DRIVER_DIRECTFB_DYNAMIC @SDL_VIDEO_DRIVER_DIRECTFB_DYNAMIC@
 #cmakedefine SDL_VIDEO_DRIVER_DUMMY @SDL_VIDEO_DRIVER_DUMMY@
@@ -396,6 +398,7 @@
 #cmakedefine SDL_POWER_LINUX @SDL_POWER_LINUX@
 #cmakedefine SDL_POWER_WINDOWS @SDL_POWER_WINDOWS@
 #cmakedefine SDL_POWER_MACOSX @SDL_POWER_MACOSX@
+#cmakedefine SDL_POWER_UIKIT @SDL_POWER_UIKIT@
 #cmakedefine SDL_POWER_HAIKU @SDL_POWER_HAIKU@
 #cmakedefine SDL_POWER_EMSCRIPTEN @SDL_POWER_EMSCRIPTEN@
 #cmakedefine SDL_POWER_HARDWIRED @SDL_POWER_HARDWIRED@
@@ -417,6 +420,9 @@
 #cmakedefine SDL_LIBSAMPLERATE_DYNAMIC @SDL_LIBSAMPLERATE_DYNAMIC@
 
 /* Platform specific definitions */
+#cmakedefine SDL_IPHONE_KEYBOARD @SDL_IPHONE_KEYBOARD@
+#cmakedefine SDL_IPHONE_LAUNCHSCREEN @SDL_IPHONE_LAUNCHSCREEN@
+
 #if !defined(__WIN32__)
 #  if !defined(_STDINT_H_) && !defined(_STDINT_H) && !defined(HAVE_STDINT_H) && !defined(_HAVE_STDINT_H)
 typedef unsigned int size_t;

test/CMakeLists.txt

@@ -101,22 +101,52 @@ endforeach(RESOURCE_FILE)
 file(COPY ${RESOURCE_FILES} DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
 
 # TODO: Might be easier to make all targets depend on the resources...?
-add_dependencies(testscale SDL2_test_resoureces)
-add_dependencies(testrendercopyex SDL2_test_resoureces)
-add_dependencies(controllermap SDL2_test_resoureces)
-add_dependencies(testyuv SDL2_test_resoureces)
-add_dependencies(testgamecontroller SDL2_test_resoureces)
-add_dependencies(testshape SDL2_test_resoureces)
-add_dependencies(testshader SDL2_test_resoureces)
-add_dependencies(testnative SDL2_test_resoureces)
-add_dependencies(testspriteminimal SDL2_test_resoureces)
-add_dependencies(testautomation SDL2_test_resoureces)
-add_dependencies(testcustomcursor SDL2_test_resoureces)
-add_dependencies(testrendertarget SDL2_test_resoureces)
-add_dependencies(testsprite2 SDL2_test_resoureces)
 
-add_dependencies(loopwave SDL2_test_resoureces)
-add_dependencies(loopwavequeue SDL2_test_resoureces)
-add_dependencies(testresample SDL2_test_resoureces)
-add_dependencies(testaudiohotplug SDL2_test_resoureces)
-add_dependencies(testmultiaudio SDL2_test_resoureces)
+set(NEEDS_RESOURCES
+    testscale
+    testrendercopyex
+    controllermap
+    testyuv
+    testgamecontroller
+    testshape
+    testshader
+    testnative
+    testspriteminimal
+    testautomation
+    testcustomcursor
+    testrendertarget
+    testsprite2
+    loopwave
+    loopwavequeue
+    testresample
+    testaudiohotplug
+    testmultiaudio
+)
+foreach(APP IN LISTS NEEDS_RESOURCES)
+    add_dependencies(${APP} SDL2_test_resoureces)
+    if(APPLE)
+        # Make sure resource files get installed into macOS/iOS .app bundles.  
+        target_sources(${APP} PRIVATE "${RESOURCE_FILES}")
+        set_target_properties(${APP} PROPERTIES RESOURCE "${RESOURCE_FILES}")
+    endif()
+endforeach()
+
+# Set Apple App ID / Bundle ID.  This is needed to launch apps on some Apple
+# platforms (iOS, for example).
+if(APPLE)
+    if(${CMAKE_VERSION} VERSION_LESS "3.7.0")
+        # CMake's 'BUILDSYSTEM_TARGETS' property is only available in
+        # CMake 3.7 and above.
+        message(WARNING "Unable to set Bundle ID for Apple .app builds due to old CMake (pre 3.7).")
+    else()
+        get_property(TARGETS DIRECTORY ${CMAKE_CURRENT_LIST_DIR} PROPERTY BUILDSYSTEM_TARGETS)
+        foreach(CURRENT_TARGET IN LISTS TARGETS)
+            get_property(TARGET_TYPE TARGET ${CURRENT_TARGET} PROPERTY TYPE)
+            if(TARGET_TYPE STREQUAL "EXECUTABLE")
+                set_target_properties("${CURRENT_TARGET}" PROPERTIES
+                    MACOSX_BUNDLE_GUI_IDENTIFIER "org.libsdl.${CURRENT_TARGET}"
+                )
+            endif()
+        endforeach()
+    endif()
+endif()