Created attachment 3259 [details]
Modified SDL2 CMakeLists.txt file

When I use CMake to generate an Xcode project and then try to link SDL2 to a program that uses it for iOS arm64, I get this error:
Undefined symbols for architecture arm64:
  "_METAL_RenderDriver", referenced from:
      _render_drivers in libSDL2d.a(SDL_render.o)
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I perform the CMake project generation and build steps with the following commands:
mkdir _build
cd _build
cmake -G Xcode -DCMAKE_TOOLCHAIN_FILE=../ios.toolchain.cmake -DENABLE_BITCODE=FALSE ..
cmake --build . --config Release

I'm using the compiler that comes with Xcode 9.4 to build.

The toolchain file, ios.toolchain.cmake, is from here:
https://github.com/leetal/ios-cmake


It's missing a source file in SDL2 to define this symbol.  I fix it by adding the following after file(GLOB SOURCE_FILES in CMakeLists.txt:
if(IOS)
   set(SOURCE_FILES ${SOURCE_FILES} ${SDL2_SOURCE_DIR}/src/render/metal/SDL_render_metal.m)
endif()


I also need to add "-framework Metal" to the IOS_FRAMEWORKS list originally added in this bug report:
https://bugzilla.libsdl.org/show_bug.cgi?id=4178

The CMakeLists.txt file with these changes and the changes from my other build bugs is attached.

Verified that iOS builds for armv7, armv7s, arm64, and the x86_64 simulator still work along with Windows, Linux, Mac, and Android.