cmake: use genexes for linking against apple frameworks

cmake/sdlchecks.cmake

@@ -119,7 +119,7 @@ macro(CheckALSA)
         endif()
       endif()
       if(NOT HAVE_ALSA_SHARED)
-        list(APPEND CMAKE_DEPENDS ALSA::ALSA)
+        list(APPEND CMAKE_LIBS ALSA::ALSA)
         list(APPEND PKGCONFIG_DEPENDS alsa)
       endif()
       set(HAVE_SDL_AUDIO TRUE)

cmake/test/CMakeLists.txt

@@ -3,6 +3,8 @@
 cmake_minimum_required(VERSION 3.12)
 project(sdl_test LANGUAGES C)
 
+include(CheckLanguage)
+include(FeatureSummary)
 include(GenerateExportHeader)
 
 if(ANDROID)
@@ -19,14 +21,23 @@ cmake_policy(SET CMP0074 NEW)
 # Override CMAKE_FIND_ROOT_PATH_MODE to allow search for SDL2 outside of sysroot
 set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE NEVER)
 
-include(FeatureSummary)
-
 option(TEST_SHARED "Test linking to shared SDL2 library" ON)
 add_feature_info("TEST_SHARED" TEST_SHARED "Test linking with shared library")
 
 option(TEST_STATIC "Test linking to static SDL2 library" ON)
 add_feature_info("TEST_STATIC" TEST_STATIC "Test linking with static library")
 
+if(APPLE)
+    # multiple values for CMAKE_OSX_ARCHITECTURES not supported with Swift
+    list(LENGTH CMAKE_OSX_ARCHITECTURES count_osx_archs)
+    if(count_osx_archs LESS_EQUAL 1)
+        check_language(Swift)
+        if(CMAKE_Swift_COMPILER)
+            enable_language(Swift)
+        endif()
+    endif()
+endif()
+
 if(TEST_SHARED)
     find_package(SDL2 REQUIRED CONFIG COMPONENTS SDL2)
     if(EMSCRIPTEN OR (WIN32 AND NOT WINDOWS_STORE))
@@ -75,6 +86,12 @@ if(TEST_SHARED)
     generate_export_header(sharedlib-shared-vars EXPORT_MACRO_NAME MYLIBRARY_EXPORT)
     target_compile_definitions(sharedlib-shared-vars PRIVATE "EXPORT_HEADER=\"${CMAKE_CURRENT_BINARY_DIR}/sharedlib-shared-vars_export.h\"")
     set_target_properties(sharedlib-shared-vars PROPERTIES C_VISIBILITY_PRESET "hidden")
+
+    if(CMAKE_Swift_COMPILER)
+        add_executable(swift-shared main.swift)
+        target_include_directories(swift-shared PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/swift")
+        target_link_libraries(swift-shared PRIVATE SDL2::SDL2)
+    endif()
 endif()
 
 if(TEST_STATIC)
@@ -111,6 +128,12 @@ if(TEST_STATIC)
         target_link_libraries(cli-static-vars PRIVATE ${SDL2_STATIC_LIBRARIES})
         target_include_directories(cli-static-vars PRIVATE ${SDL2_INCLUDE_DIRS})
     endif()
+
+    if(CMAKE_Swift_COMPILER)
+        add_executable(swift-static main.swift)
+        target_include_directories(swift-static PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/swift")
+        target_link_libraries(swift-static PRIVATE SDL2::SDL2-static)
+    endif()
 endif()
 
 message(STATUS "SDL2_PREFIX:            ${SDL2_PREFIX}")

cmake/test/main.swift

@@ -0,0 +1,12 @@
+/* Contributed by Piotr Usewicz (https://github.com/pusewicz) */
+
+import SDL2
+
+guard SDL_Init(Uint32(SDL_INIT_VIDEO)) == 0 else {
+  fatalError("SDL_Init error: \(String(cString: SDL_GetError()))")
+}
+
+var sdlVersion = SDL_version()
+SDL_GetVersion(&sdlVersion)
+
+print("SDL version: \(sdlVersion.major).\(sdlVersion.minor).\(sdlVersion.patch)")

cmake/test/swift/module.modulemap

@@ -0,0 +1,4 @@
+module SDL2 [extern_c] {
+    header "shim.h"
+    export *
+}

cmake/test/swift/shim.h

@@ -0,0 +1,3 @@
+/* Contributed by Piotr Usewicz (https://github.com/pusewicz) */
+
+#include "SDL.h"