CMakeLists.txt

if(${CMAKE_CURRENT_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_BINARY_DIR})
  message(FATAL_ERROR "Prevented in-tree build. Please create a build directory outside of the SDL source code and run \"cmake -S ${CMAKE_SOURCE_DIR} -B .\" from there")
endif()

cmake_minimum_required(VERSION 3.0.0)
project(SDL2 C CXX)

if (HAIKU)
  set(LINKER_LANGUAGE CXX)
endif()

# This is a virtual "library" that just exists to collect up compiler and
#  linker options that used to be global to this CMake project. When you
#  specify it as part of a real library's target_link_libraries(), that
#  library will also gain all those build options too. This is meant to
#  modularize old calls to the global add_definitions and include_directories,
#  etc. See https://github.com/libsdl-org/SDL/issues/4150
add_library(sdl-build-options INTERFACE)

if(WINDOWS_STORE)
  cmake_minimum_required(VERSION 3.11.0)
  target_compile_definitions(sdl-build-options INTERFACE "-DSDL_BUILDING_WINRT=1")
  target_compile_options(sdl-build-options INTERFACE "-ZW")
endif()

# Build in parallel under Visual Studio. Not enabled by default.
if(MSVC)
  target_compile_options(sdl-build-options INTERFACE "/MP")
endif(MSVC)


# !!! FIXME: this should probably do "MACOSX_RPATH ON" as a target property
# !!! FIXME:  for the SDL2 shared library (so you get an
# !!! FIXME:  install_name ("soname") of "@rpath/libSDL-whatever.dylib"
# !!! FIXME:  instead of "/usr/local/lib/libSDL-whatever.dylib"), but I'm
# !!! FIXME:  punting for now and leaving the existing behavior. Until this
# !!! FIXME:  properly resolved, this line silences a warning in CMake 3.0+.
# !!! FIXME:  remove it and this comment entirely once the problem is
# !!! FIXME:  properly resolved.
#cmake_policy(SET CMP0042 OLD)

include(CheckLibraryExists)
include(CheckIncludeFiles)
include(CheckIncludeFile)
include(CheckSymbolExists)
include(CheckCSourceCompiles)
include(CheckCSourceRuns)
include(CheckCCompilerFlag)
include(CheckCXXCompilerFlag)
include(CheckTypeSize)
include(CheckStructHasMember)
include(CMakeDependentOption)
include(FindPkgConfig)
include(GNUInstallDirs)
set(CMAKE_MODULE_PATH "${SDL2_SOURCE_DIR}/cmake")
include(${SDL2_SOURCE_DIR}/cmake/macros.cmake)
include(${SDL2_SOURCE_DIR}/cmake/sdlchecks.cmake)

# General settings
# Edit include/SDL_version.h and change the version, then:
#   SDL_MICRO_VERSION += 1;
#   SDL_INTERFACE_AGE += 1;
#   SDL_BINARY_AGE += 1;
# if any functions have been added, set SDL_INTERFACE_AGE to 0.
# if backwards compatibility has been broken,
# set SDL_BINARY_AGE and SDL_INTERFACE_AGE to 0.
set(SDL_MAJOR_VERSION 2)
set(SDL_MINOR_VERSION 0)
set(SDL_MICRO_VERSION 20)
set(SDL_INTERFACE_AGE 2)
set(SDL_BINARY_AGE 20)
set(SDL_VERSION "${SDL_MAJOR_VERSION}.${SDL_MINOR_VERSION}.${SDL_MICRO_VERSION}")
# the following should match the versions in Xcode project file:
set(DYLIB_CURRENT_VERSION 19.2.0)
set(DYLIB_COMPATIBILITY_VERSION 1.0.0)

# Set defaults preventing destination file conflicts
set(SDL_CMAKE_DEBUG_POSTFIX "d"
    CACHE STRING "Name suffix for debug builds")

mark_as_advanced(CMAKE_IMPORT_LIBRARY_SUFFIX SDL_CMAKE_DEBUG_POSTFIX)

# Calculate a libtool-like version number
math(EXPR LT_CURRENT "${SDL_MICRO_VERSION} - ${SDL_INTERFACE_AGE}")
math(EXPR LT_AGE "${SDL_BINARY_AGE} - ${SDL_INTERFACE_AGE}")
math(EXPR LT_MAJOR "${LT_CURRENT}- ${LT_AGE}")
set(LT_REVISION "${SDL_INTERFACE_AGE}")
set(LT_RELEASE "${SDL_MAJOR_VERSION}.${SDL_MINOR_VERSION}")
set(LT_VERSION "${LT_MAJOR}.${LT_AGE}.${LT_REVISION}")

#message(STATUS "${LT_VERSION} :: ${LT_AGE} :: ${LT_REVISION} :: ${LT_CURRENT} :: ${LT_RELEASE}")

# General settings & flags
set(LIBRARY_OUTPUT_DIRECTORY "build")
# Check for 64 or 32 bit
set(SIZEOF_VOIDP ${CMAKE_SIZEOF_VOID_P})
if(CMAKE_SIZEOF_VOID_P EQUAL 8)
  set(ARCH_64 TRUE)
  set(PROCESSOR_ARCH "x64")
else()
  set(ARCH_64 FALSE)
  set(PROCESSOR_ARCH "x86")
endif()
set(LIBNAME SDL2)
if(NOT LIBTYPE)
  set(LIBTYPE SHARED)
endif()

# Get the platform
if(WIN32)
  if(NOT WINDOWS)
    set(WINDOWS TRUE)
  endif()
elseif(UNIX AND NOT APPLE)
  if(CMAKE_SYSTEM_NAME MATCHES ".*Linux")
    set(LINUX TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES "kFreeBSD.*")
    set(FREEBSD TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES "kNetBSD.*|NetBSD.*")
    set(NETBSD TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES "kOpenBSD.*|OpenBSD.*")
    set(OPENBSD TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES ".*GNU.*")
    set(GNU TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES ".*BSDI.*")
    set(BSDI TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES "DragonFly.*|FreeBSD")
    set(FREEBSD TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES "SYSV5.*")
    set(SYSV5 TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES "Solaris.*")
    set(SOLARIS TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES "HP-UX.*")
    set(HPUX TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES "AIX.*")
    set(AIX TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES "Minix.*")
    set(MINIX TRUE)
  endif()
elseif(APPLE)
  if(CMAKE_SYSTEM_NAME MATCHES ".*Darwin.*")
    set(DARWIN TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES ".*MacOS.*")
    set(MACOSX TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES ".*tvOS.*")
    set(TVOS TRUE)
  elseif(CMAKE_SYSTEM_NAME MATCHES ".*iOS.*")
    # !!! FIXME: remove the version check when we start requiring >= 3.14.0
    if(CMAKE_VERSION VERSION_LESS 3.14)
      set(IOS TRUE)
    endif()
  endif()
elseif(CMAKE_SYSTEM_NAME MATCHES "BeOS.*")
  message_error("BeOS support has been removed as of SDL 2.0.2.")
elseif(CMAKE_SYSTEM_NAME MATCHES "Haiku.*")
  set(HAIKU TRUE)
endif()

# Don't mistake osx for unix
if(UNIX AND NOT APPLE AND NOT RISCOS)
  set(UNIX_SYS ON)
else()
  set(UNIX_SYS OFF)
endif()

if(UNIX OR APPLE)
  set(UNIX_OR_MAC_SYS ON)
else()
  set(UNIX_OR_MAC_SYS OFF)
endif()

# Emscripten pthreads work, but you need to have a non-pthread fallback build
#  for systems without support. It's not currently enough to not use
#  pthread functions in a pthread-build; it won't start up on unsupported
#  browsers. As such, you have to explicitly enable it on Emscripten builds
#  for the time being. This default with change to ON once this becomes
#  commonly supported in browsers or the Emscripten teams makes a single
#  binary work everywhere.
if (UNIX_OR_MAC_SYS AND NOT EMSCRIPTEN)
  set(SDL_PTHREADS_ENABLED_BY_DEFAULT ON)
else()
  set(SDL_PTHREADS_ENABLED_BY_DEFAULT OFF)
endif()

# The hidraw support doesn't catch Xbox, PS4 and Nintendo controllers,
#  so we'll just use libusb when it's available. libusb does not support iOS,
#  so we default to yes on iOS.
#  TODO: Windows can support libusb, the hid.c file just depends on Unix APIs
if((WINDOWS AND NOT WINDOWS_STORE) OR IOS OR TVOS OR ANDROID)
  set(HIDAPI_SKIP_LIBUSB TRUE)
else()
  set(HIDAPI_SKIP_LIBUSB FALSE)
endif()

# On the other hand, *BSD specifically uses libusb only, so we make a special
#  case just for them.
if(FREEBSD OR NETBSD OR OPENBSD OR BSDI)
  set(HIDAPI_ONLY_LIBUSB TRUE)
else()
  set(HIDAPI_ONLY_LIBUSB FALSE)
endif()

# Compiler info
if(CMAKE_C_COMPILER_ID MATCHES "Clang")
  set(USE_CLANG TRUE)
  set(OPT_DEF_ASM TRUE)
  # Visual Studio 2019 v16.2 added support for Clang/LLVM.
  # Check if a Visual Studio project is being generated with the Clang toolset.
  if(MSVC)
    set(MSVC_CLANG TRUE)
  endif()
elseif(CMAKE_COMPILER_IS_GNUCC)
  set(USE_GCC TRUE)
  set(OPT_DEF_ASM TRUE)
elseif(MSVC_VERSION GREATER 1400) # VisualStudio 8.0+
  set(OPT_DEF_ASM TRUE)
  #set(CMAKE_C_FLAGS "/ZI /WX- /
else()
  set(OPT_DEF_ASM FALSE)
endif()

if(USE_GCC OR USE_CLANG)
  set(OPT_DEF_GCC_ATOMICS ON)
endif()

# Default option knobs
if(APPLE OR ARCH_64 OR MSVC_CLANG)
  if(NOT "${CMAKE_OSX_ARCHITECTURES}" MATCHES "arm")
    set(OPT_DEF_SSEMATH ON)
  endif()
endif()
if(UNIX OR MINGW OR MSYS OR (USE_CLANG AND NOT WINDOWS) OR VITA OR PSP)
  set(OPT_DEF_LIBC ON)
endif()

if(NOT ("$ENV{CFLAGS}" STREQUAL ""))
  if(CMAKE_VERSION VERSION_LESS 3.11.0)
     message(WARNING "SDL's CMakeLists.txt no longer checks the CFLAGS environment.")
     message(WARNING "Please use CMake's CMAKE_C_FLAGS and CMAKE_BUILD_TYPE variables directly.")
     message(WARNING "Or upgrade to CMake >= 3.11.0, which respects the CFLAGS environment var.")
  endif()
endif()

if(MSVC)
  option(SDL_FORCE_STATIC_VCRT "Force /MT for static VC runtimes" OFF)
  if(SDL_FORCE_STATIC_VCRT)
    foreach(flag_var
        CMAKE_C_FLAGS CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_RELEASE
        CMAKE_C_FLAGS_MINSIZEREL CMAKE_C_FLAGS_RELWITHDEBINFO)
      if(${flag_var} MATCHES "/MD")
        string(REGEX REPLACE "/MD" "/MT" ${flag_var} "${${flag_var}}")
      endif()
    endforeach()
  endif()

  if(NOT SDL_LIBC)
    # Make sure /RTC1 is disabled, otherwise it will use functions from the CRT
    foreach(flag_var
        CMAKE_C_FLAGS CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_RELEASE
        CMAKE_C_FLAGS_MINSIZEREL CMAKE_C_FLAGS_RELWITHDEBINFO)
      string(REGEX REPLACE "/RTC(su|[1su])" "" ${flag_var} "${${flag_var}}")
    endforeach(flag_var)
  endif()

  if(MSVC_CLANG)
    # clang-cl treats /W4 as '-Wall -Wextra' -- we don't need -Wextra
    foreach(flag_var
        CMAKE_C_FLAGS CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_RELEASE
        CMAKE_C_FLAGS_MINSIZEREL CMAKE_C_FLAGS_RELWITHDEBINFO)
      string(REGEX REPLACE "/W4" "/W3" ${flag_var} "${${flag_var}}")
    endforeach(flag_var)
  endif()
endif()

# Those are used for pkg-config and friends, so that the SDL2.pc, sdl2-config,
# etc. are created correctly.
set(SDL_LIBS "-lSDL2")
set(SDL_CFLAGS "")

# When building shared lib for Windows with MinGW,
# avoid the DLL having a "lib" prefix
if(WINDOWS)
  set(CMAKE_SHARED_LIBRARY_PREFIX "")
endif()

# Emscripten toolchain has a nonempty default value for this, and the checks
# in this file need to change that, so remember the original value, and
# restore back to that afterwards. For check_function_exists() to work in
# Emscripten, this value must be at its default value.
set(ORIG_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})

if(CYGWIN)
  # We build SDL on cygwin without the UNIX emulation layer
  target_include_directories(sdl-build-options INTERFACE "/usr/include/mingw")
  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -mno-cygwin")
  check_c_source_compiles("int main(int argc, char **argv) {}"
    HAVE_GCC_NO_CYGWIN)
  set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})
  if(HAVE_GCC_NO_CYGWIN)
    list(APPEND EXTRA_LDFLAGS "-mno-cygwin")
    list(APPEND SDL_LIBS "-mno-cygwin")
  endif()
  set(SDL_CFLAGS "${SDL_CFLAGS} -I/usr/include/mingw")
endif()

# General includes
target_compile_definitions(sdl-build-options INTERFACE "-DUSING_GENERATED_CONFIG_H")
target_include_directories(sdl-build-options BEFORE INTERFACE "${SDL2_BINARY_DIR}/include")
target_include_directories(sdl-build-options INTERFACE "${SDL2_SOURCE_DIR}/include")
# Note: The clang toolset for Visual Studio does not support the '-idirafter' option.
if(USE_GCC OR (USE_CLANG AND NOT MSVC_CLANG))
  # !!! FIXME: do we _need_ to mess with CMAKE_C_FLAGS here?
  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -idirafter \"${SDL2_SOURCE_DIR}/src/video/khronos\"")
else()
  target_include_directories(sdl-build-options INTERFACE "${SDL2_SOURCE_DIR}/src/video/khronos")
endif()

# All these ENABLED_BY_DEFAULT vars will default to ON if not specified, so
#  you only need to have a platform override them if they are disabling.
set(OPT_DEF_ASM TRUE)
if(EMSCRIPTEN)
  # Set up default values for the currently supported set of subsystems:
  # Emscripten/Javascript does not have assembly support, a dynamic library
  # loading architecture, or low-level CPU inspection.

  # SDL_THREADS_ENABLED_BY_DEFAULT now defaults to ON, but pthread support might be disabled by default.
  # !!! FIXME: most of these subsystems should default to ON if there are dummy implementations to be used.

  set(OPT_DEF_ASM FALSE)
  set(SDL_SHARED_ENABLED_BY_DEFAULT OFF)
  set(SDL_ATOMIC_ENABLED_BY_DEFAULT OFF)
  set(SDL_LOADSO_ENABLED_BY_DEFAULT OFF)
  set(SDL_CPUINFO_ENABLED_BY_DEFAULT OFF)
endif()

if(VITA OR PSP)
  set(SDL_SHARED_ENABLED_BY_DEFAULT OFF)
  set(SDL_LOADSO_ENABLED_BY_DEFAULT OFF)
endif()

# When defined, respect CMake's BUILD_SHARED_LIBS setting:
set(SDL_STATIC_ENABLED_BY_DEFAULT ON)
if (NOT DEFINED SDL_SHARED_ENABLED_BY_DEFAULT)
  # ...unless decided already (as for EMSCRIPTEN)

  set(SDL_SHARED_ENABLED_BY_DEFAULT OFF)

  if (NOT DEFINED BUILD_SHARED_LIBS)
    # No preference? Build both, just like the AC/AM configure
    set(SDL_SHARED_ENABLED_BY_DEFAULT ON)

  elseif (BUILD_SHARED_LIBS)
    # In this case, we assume the user wants a shared lib and don't build
    # the static one
    set(SDL_SHARED_ENABLED_BY_DEFAULT ON)
    set(SDL_STATIC_ENABLED_BY_DEFAULT OFF)
  endif()
endif()

set(LONGESTOPTIONNAME 0)  # set_option and friends will change this.

set(SDL_SUBSYSTEMS
    Atomic Audio Video Render Events Joystick Haptic Hidapi Power Threads Timers
    File Loadso CPUinfo Filesystem Dlopen Sensor Locale)
foreach(_SUB ${SDL_SUBSYSTEMS})
  string(TOUPPER ${_SUB} _OPT)
  if (NOT DEFINED SDL_${_OPT}_ENABLED_BY_DEFAULT)
    set(SDL_${_OPT}_ENABLED_BY_DEFAULT ON)
  endif()
  option(SDL_${_OPT} "Enable the ${_SUB} subsystem" ${SDL_${_OPT}_ENABLED_BY_DEFAULT})
endforeach()

option_string(SDL_ASSERTIONS "Enable internal sanity checks (auto/disabled/release/enabled/paranoid)" "auto")
#set_option(SDL_DEPENDENCY_TRACKING "Use gcc -MMD -MT dependency tracking" ON)
set_option(SDL_LIBC                "Use the system C library" ${OPT_DEF_LIBC})
set_option(SDL_GCC_ATOMICS         "Use gcc builtin atomics" ${OPT_DEF_GCC_ATOMICS})
set_option(SDL_ASSEMBLY            "Enable assembly routines" ${OPT_DEF_ASM})
set_option(SDL_SSEMATH             "Allow GCC to use SSE floating point math" ${OPT_DEF_SSEMATH})
set_option(SDL_MMX                 "Use MMX assembly routines" ${OPT_DEF_ASM})
set_option(SDL_3DNOW               "Use 3Dnow! MMX assembly routines" ${OPT_DEF_ASM})
set_option(SDL_SSE                 "Use SSE assembly routines" ${OPT_DEF_ASM})
set_option(SDL_SSE2                "Use SSE2 assembly routines" ${OPT_DEF_SSEMATH})
set_option(SDL_SSE3                "Use SSE3 assembly routines" ${OPT_DEF_SSEMATH})
set_option(SDL_ALTIVEC             "Use Altivec assembly routines" ${OPT_DEF_ASM})
set_option(SDL_ARMSIMD             "use SIMD assembly blitters on ARM" OFF)
set_option(SDL_ARMNEON             "use NEON assembly blitters on ARM" OFF)
set_option(SDL_DISKAUDIO           "Support the disk writer audio driver" ON)
set_option(SDL_DUMMYAUDIO          "Support the dummy audio driver" ON)
set_option(SDL_DIRECTFB            "Use DirectFB video driver" OFF)
dep_option(SDL_DIRECTFB_SHARED     "Dynamically load directfb support" ON "SDL_DIRECTFB" OFF)
set_option(SDL_DUMMYVIDEO          "Use dummy video driver" ON)
set_option(SDL_OPENGL              "Include OpenGL support" ON)
set_option(SDL_OPENGLES            "Include OpenGL ES support" ON)
set_option(SDL_PTHREADS            "Use POSIX threads for multi-threading" ${SDL_PTHREADS_ENABLED_BY_DEFAULT})
dep_option(SDL_PTHREADS_SEM        "Use pthread semaphores" ON "SDL_PTHREADS" OFF)
dep_option(SDL_OSS                 "Support the OSS audio API" ON "UNIX_SYS OR RISCOS" OFF)
set_option(SDL_ALSA                "Support the ALSA audio API" ${UNIX_SYS})
dep_option(SDL_ALSA_SHARED         "Dynamically load ALSA audio support" ON "SDL_ALSA" OFF)
set_option(SDL_JACK                "Support the JACK audio API" ${UNIX_SYS})
dep_option(SDL_JACK_SHARED         "Dynamically load JACK audio support" ON "SDL_JACK" OFF)
set_option(SDL_ESD                 "Support the Enlightened Sound Daemon" ${UNIX_SYS})
dep_option(SDL_ESD_SHARED          "Dynamically load ESD audio support" ON "SDL_ESD" OFF)
set_option(SDL_PIPEWIRE            "Use Pipewire audio" ${UNIX_SYS})
dep_option(SDL_PIPEWIRE_SHARED     "Dynamically load Pipewire support" ON "SDL_PIPEWIRE" OFF)
set_option(SDL_PULSEAUDIO          "Use PulseAudio" ${UNIX_SYS})
dep_option(SDL_PULSEAUDIO_SHARED   "Dynamically load PulseAudio support" ON "SDL_PULSEAUDIO" OFF)
set_option(SDL_ARTS                "Support the Analog Real Time Synthesizer" ${UNIX_SYS})
dep_option(SDL_ARTS_SHARED         "Dynamically load aRts audio support" ON "SDL_ARTS" OFF)
set_option(SDL_NAS                 "Support the NAS audio API" ${UNIX_SYS})
dep_option(SDL_NAS_SHARED          "Dynamically load NAS audio support" ON "SDL_NAS" OFF)
set_option(SDL_SNDIO               "Support the sndio audio API" ${UNIX_SYS})
dep_option(SDL_SNDIO_SHARED        "Dynamically load the sndio audio API" ${UNIX_SYS} ON "SDL_SNDIO" OFF)
set_option(SDL_FUSIONSOUND         "Use FusionSound audio driver" OFF)
dep_option(SDL_FUSIONSOUND_SHARED  "Dynamically load fusionsound audio support" ON "SDL_FUSIONSOUND" OFF)
set_option(SDL_LIBSAMPLERATE       "Use libsamplerate for audio rate conversion" ${UNIX_SYS})
dep_option(SDL_LIBSAMPLERATE_SHARED "Dynamically load libsamplerate" ON "SDL_LIBSAMPLERATE" OFF)
set_option(SDL_RPATH               "Use an rpath when linking SDL" ${UNIX_SYS})
set_option(SDL_CLOCK_GETTIME       "Use clock_gettime() instead of gettimeofday()" ${UNIX_SYS})
set_option(SDL_X11                 "Use X11 video driver" ${UNIX_SYS})
dep_option(SDL_X11_SHARED          "Dynamically load X11 support" ON "SDL_X11" OFF)
set(SDL_X11_OPTIONS Xcursor Xdbe Xinerama XInput Xfixes Xrandr Xscrnsaver XShape Xvm)
foreach(_SUB ${SDL_X11_OPTIONS})
  string(TOUPPER "SDL_X11_${_SUB}" _OPT)
  dep_option(${_OPT}               "Enable ${_SUB} support" ON "SDL_X11" OFF)
endforeach()
set_option(SDL_WAYLAND             "Use Wayland video driver" ${UNIX_SYS})
dep_option(SDL_WAYLAND_SHARED      "Dynamically load Wayland support" ON "SDL_WAYLAND" OFF)
dep_option(SDL_WAYLAND_LIBDECOR    "Use client-side window decorations on Wayland" ON "SDL_WAYLAND" ON)
dep_option(SDL_WAYLAND_LIBDECOR_SHARED     "Dynamically load libdecor support" ON "SDL_WAYLAND_LIBDECOR" OFF)
dep_option(SDL_WAYLAND_QT_TOUCH    "QtWayland server support for Wayland video driver" ON "SDL_WAYLAND" OFF)
set_option(SDL_RPI                 "Use Raspberry Pi video driver" ${UNIX_SYS})
set_option(SDL_COCOA               "Use Cocoa video driver" ${APPLE})
set_option(SDL_DIRECTX             "Use DirectX for Windows audio/video" ${WINDOWS})
set_option(SDL_XINPUT              "Use Xinput for Windows" ${WINDOWS})
set_option(SDL_WASAPI              "Use the Windows WASAPI audio driver" ${WINDOWS})
set_option(SDL_RENDER_D3D          "Enable the Direct3D render driver" ${WINDOWS})
set_option(SDL_RENDER_METAL        "Enable the Metal render driver" ${APPLE})
set_option(SDL_VIVANTE             "Use Vivante EGL video driver" ${UNIX_SYS})
dep_option(SDL_VULKAN              "Enable Vulkan support" ON "ANDROID OR APPLE OR LINUX OR WINDOWS" OFF)
set_option(SDL_METAL               "Enable Metal support" ${APPLE})
set_option(SDL_KMSDRM              "Use KMS DRM video driver" ${UNIX_SYS})
dep_option(SDL_KMSDRM_SHARED       "Dynamically load KMS DRM support" ON "SDL_KMSDRM" OFF)
set_option(SDL_OFFSCREEN           "Use offscreen video driver" OFF)
option_string(SDL_BACKGROUNDING_SIGNAL "number to use for magic backgrounding signal or 'OFF'" OFF)
option_string(SDL_FOREGROUNDING_SIGNAL "number to use for magic foregrounding signal or 'OFF'" OFF)
set_option(SDL_HIDAPI_JOYSTICK     "Use HIDAPI for low level joystick drivers" ON)
set_option(SDL_VIRTUAL_JOYSTICK    "Enable the virtual-joystick driver" ON)
set_option(SDL_ASAN                "Use AddressSanitizer to detect memory errors" OFF)

set(SDL_SHARED ${SDL_SHARED_ENABLED_BY_DEFAULT} CACHE BOOL "Build a shared version of the library")
set(SDL_STATIC ${SDL_STATIC_ENABLED_BY_DEFAULT} CACHE BOOL "Build a static version of the library")

dep_option(SDL_STATIC_PIC      "Static version of the library should be built with Position Independent Code" OFF "SDL_STATIC" OFF)
set_option(SDL_TEST            "Build the test directory" OFF)

if(VITA)
    set_option(VIDEO_VITA_PIB  "Build with PSVita piglet gles2 support" OFF)
    set_option(VIDEO_VITA_PVR  "Build with PSVita PVR gles/gles2 support" OFF)
endif()

# General source files
file(GLOB SOURCE_FILES
  ${SDL2_SOURCE_DIR}/src/*.c
  ${SDL2_SOURCE_DIR}/src/atomic/*.c
  ${SDL2_SOURCE_DIR}/src/audio/*.c
  ${SDL2_SOURCE_DIR}/src/cpuinfo/*.c
  ${SDL2_SOURCE_DIR}/src/dynapi/*.c
  ${SDL2_SOURCE_DIR}/src/events/*.c
  ${SDL2_SOURCE_DIR}/src/file/*.c
  ${SDL2_SOURCE_DIR}/src/haptic/*.c
  ${SDL2_SOURCE_DIR}/src/hidapi/*.c
  ${SDL2_SOURCE_DIR}/src/libm/*.c
  ${SDL2_SOURCE_DIR}/src/locale/*.c
  ${SDL2_SOURCE_DIR}/src/misc/*.c
  ${SDL2_SOURCE_DIR}/src/power/*.c
  ${SDL2_SOURCE_DIR}/src/render/*.c
  ${SDL2_SOURCE_DIR}/src/render/*/*.c
  ${SDL2_SOURCE_DIR}/src/sensor/*.c
  ${SDL2_SOURCE_DIR}/src/stdlib/*.c
  ${SDL2_SOURCE_DIR}/src/thread/*.c
  ${SDL2_SOURCE_DIR}/src/timer/*.c
  ${SDL2_SOURCE_DIR}/src/video/*.c
  ${SDL2_SOURCE_DIR}/src/video/yuv2rgb/*.c)


if(SDL_ASSERTIONS STREQUAL "auto")
  # Do nada - use optimization settings to determine the assertion level
elseif(SDL_ASSERTIONS STREQUAL "disabled")
  set(SDL_DEFAULT_ASSERT_LEVEL 0)
elseif(SDL_ASSERTIONS STREQUAL "release")
  set(SDL_DEFAULT_ASSERT_LEVEL 1)
elseif(SDL_ASSERTIONS STREQUAL "enabled")
  set(SDL_DEFAULT_ASSERT_LEVEL 2)
elseif(SDL_ASSERTIONS STREQUAL "paranoid")
  set(SDL_DEFAULT_ASSERT_LEVEL 3)
else()
  message_error("unknown assertion level")
endif()
set(HAVE_ASSERTIONS ${SDL_ASSERTIONS})

if(NOT SDL_BACKGROUNDING_SIGNAL STREQUAL "OFF")
  target_compile_definitions(sdl-build-options INTERFACE "-DSDL_BACKGROUNDING_SIGNAL=${SDL_BACKGROUNDING_SIGNAL}")
endif()

if(NOT SDL_FOREGROUNDING_SIGNAL STREQUAL "OFF")
  target_compile_definitions(sdl-build-options INTERFACE "-DSDL_FOREGROUNDING_SIGNAL=${SDL_FOREGROUNDING_SIGNAL}")
endif()

# Compiler option evaluation
if(USE_GCC OR USE_CLANG)
  # Check for -Wall first, so later things can override pieces of it.
  # Note: clang-cl treats -Wall as -Weverything (which is very loud),
  #       /W3 as -Wall, and /W4 as -Wall -Wextra.  So: /W3 is enough.
  check_c_compiler_flag(-Wall HAVE_GCC_WALL)
  if(MSVC_CLANG)
    list(APPEND EXTRA_CFLAGS "/W3")
  elseif(HAVE_GCC_WALL)
    list(APPEND EXTRA_CFLAGS "-Wall")
    if(HAIKU)
      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-multichar")
    endif()
  endif()

  check_c_compiler_flag(-fno-strict-aliasing HAVE_GCC_NO_STRICT_ALIASING)
  if(HAVE_GCC_NO_STRICT_ALIASING)
    list(APPEND EXTRA_CFLAGS "-fno-strict-aliasing")
  endif()

  check_c_compiler_flag(-Wdeclaration-after-statement HAVE_GCC_WDECLARATION_AFTER_STATEMENT)
  if(HAVE_GCC_WDECLARATION_AFTER_STATEMENT)
    check_c_compiler_flag(-Werror=declaration-after-statement HAVE_GCC_WERROR_DECLARATION_AFTER_STATEMENT)
    if(HAVE_GCC_WERROR_DECLARATION_AFTER_STATEMENT)
      list(APPEND EXTRA_CFLAGS "-Werror=declaration-after-statement")
    endif()
    list(APPEND EXTRA_CFLAGS "-Wdeclaration-after-statement")
  endif()

  if(DEPENDENCY_TRACKING)
    check_c_source_compiles("
        #if !defined(__GNUC__) || __GNUC__ < 3
        #error Dependency tracking requires GCC 3.0 or newer
        #endif
        int main(int argc, char **argv) { }" HAVE_DEPENDENCY_TRACKING)
  endif()

  if(SDL_GCC_ATOMICS)
    check_c_source_compiles("int main(int argc, char **argv) {
        int a;
        void *x, *y, *z;
        __sync_lock_test_and_set(&a, 4);
        __sync_lock_test_and_set(&x, y);
        __sync_fetch_and_add(&a, 1);
        __sync_bool_compare_and_swap(&a, 5, 10);
        __sync_bool_compare_and_swap(&x, y, z); }" HAVE_GCC_ATOMICS)
    if(NOT HAVE_GCC_ATOMICS)
      check_c_source_compiles("int main(int argc, char **argv) {
          int a;
          __sync_lock_test_and_set(&a, 1);
          __sync_lock_release(&a); }" HAVE_GCC_SYNC_LOCK_TEST_AND_SET)
    endif()
  endif()

  set(CMAKE_REQUIRED_FLAGS "-mpreferred-stack-boundary=2")
  check_c_source_compiles("int x = 0; int main(int argc, char **argv) {}"
    HAVE_GCC_PREFERRED_STACK_BOUNDARY)
  set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

  set(CMAKE_REQUIRED_FLAGS "-fvisibility=hidden -Werror")
  check_c_source_compiles("
      #if !defined(__GNUC__) || __GNUC__ < 4
      #error SDL only uses visibility attributes in GCC 4 or newer
      #endif
      int main(int argc, char **argv) {}" HAVE_GCC_FVISIBILITY)
  if(HAVE_GCC_FVISIBILITY)
    list(APPEND EXTRA_CFLAGS "-fvisibility=hidden")
  endif()
  set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})

  check_c_compiler_flag(-Wshadow HAVE_GCC_WSHADOW)
  if(HAVE_GCC_WSHADOW)
    list(APPEND EXTRA_CFLAGS "-Wshadow")
  endif()

  if(APPLE)
    list(APPEND EXTRA_LDFLAGS "-Wl,-undefined,error")
    list(APPEND EXTRA_LDFLAGS "-Wl,-compatibility_version,${DYLIB_COMPATIBILITY_VERSION}")
    list(APPEND EXTRA_LDFLAGS "-Wl,-current_version,${DYLIB_CURRENT_VERSION}")
  elseif(NOT OPENBSD)
    set(CMAKE_REQUIRED_FLAGS "-Wl,--no-undefined")
    check_c_compiler_flag("" HAVE_NO_UNDEFINED)
    set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})
    if(HAVE_NO_UNDEFINED AND NOT (USE_CLANG AND WINDOWS))
      list(APPEND EXTRA_LDFLAGS "-Wl,--no-undefined")
    endif()
  endif()

  # Force color diagnostics when one of these conditions are met
  if(DEFINED ENV{CI} OR DEFINED ENV{USE_CCACHE} OR CMAKE_GENERATOR MATCHES Ninja)
    if(EMSCRIPTEN OR (USE_GCC AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.9))
      list(APPEND EXTRA_CFLAGS -fdiagnostics-color=always)
    elseif(USE_CLANG AND NOT CMAKE_C_COMPILER_ID MATCHES AppleClang)
      list(APPEND EXTRA_CFLAGS -fcolor-diagnostics)
    endif()
  endif()
endif()

if(SDL_ASSEMBLY)
  if(USE_GCC OR USE_CLANG)
    set(SDL_ASSEMBLY_ROUTINES 1)
    # TODO: Those all seem to be quite GCC specific - needs to be
    # reworked for better compiler support
    set(HAVE_ASSEMBLY TRUE)
    if(SDL_MMX)
      set(CMAKE_REQUIRED_FLAGS "-mmmx")
      check_c_source_compiles("
          #ifdef __MINGW32__
          #include <_mingw.h>
          #ifdef __MINGW64_VERSION_MAJOR
          #include <intrin.h>
          #else
          #include <mmintrin.h>
          #endif
          #else
          #include <mmintrin.h>
          #endif
          #ifndef __MMX__
          #error Assembler CPP flag not enabled
          #endif
          int main(int argc, char **argv) { }" HAVE_MMX)
      if(HAVE_MMX)
        list(APPEND EXTRA_CFLAGS "-mmmx")
      endif()
      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})
    endif()

    if(SDL_3DNOW)
      set(CMAKE_REQUIRED_FLAGS "-m3dnow")
      check_c_source_compiles("
          #include <mm3dnow.h>
          #ifndef __3dNOW__
          #error Assembler CPP flag not enabled
          #endif
          int main(int argc, char **argv) {
            void *p = 0;
            _m_prefetch(p);
          }" HAVE_3DNOW)
      if(HAVE_3DNOW)
        list(APPEND EXTRA_CFLAGS "-m3dnow")
      endif()
      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})
    endif()

    if(SDL_SSE)
      set(CMAKE_REQUIRED_FLAGS "-msse")
      check_c_source_compiles("
          #ifdef __MINGW32__
          #include <_mingw.h>
          #ifdef __MINGW64_VERSION_MAJOR
          #include <intrin.h>
          #else
          #include <xmmintrin.h>
          #endif
          #else
          #include <xmmintrin.h>
          #endif
          #ifndef __SSE__
          #error Assembler CPP flag not enabled
          #endif
          int main(int argc, char **argv) { }" HAVE_SSE)
      if(HAVE_SSE)
        list(APPEND EXTRA_CFLAGS "-msse")
      endif()
      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})
    endif()

    if(SDL_SSE2)
      set(CMAKE_REQUIRED_FLAGS "-msse2")
      check_c_source_compiles("
          #ifdef __MINGW32__
          #include <_mingw.h>
          #ifdef __MINGW64_VERSION_MAJOR
          #include <intrin.h>
          #else
          #include <emmintrin.h>
          #endif
          #else
          #include <emmintrin.h>
          #endif
          #ifndef __SSE2__
          #error Assembler CPP flag not enabled
          #endif
          int main(int argc, char **argv) { }" HAVE_SSE2)
      if(HAVE_SSE2)
        list(APPEND EXTRA_CFLAGS "-msse2")
      endif()
      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})
    endif()

    if(SDL_SSE3)
      set(CMAKE_REQUIRED_FLAGS "-msse3")
      check_c_source_compiles("
          #ifdef __MINGW32__
          #include <_mingw.h>
          #ifdef __MINGW64_VERSION_MAJOR
          #include <intrin.h>
          #else
          #include <pmmintrin.h>
          #endif
          #else
          #include <pmmintrin.h>
          #endif
          #ifndef __SSE3__
          #error Assembler CPP flag not enabled
          #endif
          int main(int argc, char **argv) { }" HAVE_SSE3)
      if(HAVE_SSE3)
        list(APPEND EXTRA_CFLAGS "-msse3")
      endif()
      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})
    endif()

    if(NOT SDL_SSEMATH)
      if(SDL_SSE OR SDL_SSE2 OR SDL_SSE3)
        if(USE_GCC)
          check_c_compiler_flag(-mfpmath=387 HAVE_FP_387)
          if(HAVE_FP_387)
            list(APPEND EXTRA_CFLAGS "-mfpmath=387")
          endif()
        endif()
      endif()
    else()
      set(HAVE_SSEMATH TRUE)
    endif()

    check_include_file("immintrin.h" HAVE_IMMINTRIN_H)

    if(SDL_ALTIVEC)
      set(CMAKE_REQUIRED_FLAGS "-maltivec")
      check_c_source_compiles("
          #include <altivec.h>
          vector unsigned int vzero() {
              return vec_splat_u32(0);
          }
          int main(int argc, char **argv) { }" HAVE_ALTIVEC_H_HDR)
      check_c_source_compiles("
          vector unsigned int vzero() {
              return vec_splat_u32(0);
          }
          int main(int argc, char **argv) { }" HAVE_ALTIVEC)
      set(CMAKE_REQUIRED_FLAGS ${ORIG_CMAKE_REQUIRED_FLAGS})
      if(HAVE_ALTIVEC OR HAVE_ALTIVEC_H_HDR)
        set(HAVE_ALTIVEC TRUE) # if only HAVE_ALTIVEC_H_HDR is set
        list(APPEND EXTRA_CFLAGS "-maltivec")
        set(SDL_ALTIVEC_BLITTERS 1)
        if(HAVE_ALTIVEC_H_HDR)
          set(HAVE_ALTIVEC_H 1)
        endif()
      endif()
    endif()

    if(SDL_ARMSIMD)
      set(ORIG_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
      set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -x assembler-with-cpp")
      check_c_source_compiles("
        .text
        .arch armv6
        .object_arch armv4
        .arm
        .altmacro
        #ifndef __ARM_EABI__
        #error EABI is required (to be sure that calling conventions are compatible)
        #endif
        pld [r0]
        uqadd8 r0, r0, r0
      " ARMSIMD_FOUND)
      set(CMAKE_REQUIRED_FLAGS "${ORIG_CMAKE_REQUIRED_FLAGS}")

      if(ARMSIMD_FOUND)
        set(HAVE_ARMSIMD TRUE)
        set(SDL_ARM_SIMD_BLITTERS 1)
        file(GLOB ARMSIMD_SOURCES ${SDL2_SOURCE_DIR}/src/video/arm/pixman-arm-simd*.S)
        set(SOURCE_FILES ${SOURCE_FILES} ${ARMSIMD_SOURCES})
        set(WARN_ABOUT_ARM_SIMD_ASM_MIT TRUE)
      endif()
    endif()

    if(SDL_ARMNEON)
      set(ORIG_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
      set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -x assembler-with-cpp")
      check_c_source_compiles("
        .text
        .fpu neon
        .arch armv7a
        .object_arch armv4
        .eabi_attribute 10, 0
        .arm
        .altmacro
        #ifndef __ARM_EABI__
        #error EABI is required (to be sure that calling conventions are compatible)
        #endif
        pld [r0]
        vmovn.u16 d0, q0
      " ARMNEON_FOUND)
      set(CMAKE_REQUIRED_FLAGS "${ORIG_CMAKE_REQUIRED_FLAGS}")

      if(ARMNEON_FOUND)
        set(HAVE_ARMNEON TRUE)
        set(SDL_ARM_NEON_BLITTERS 1)
        file(GLOB ARMNEON_SOURCES ${SDL2_SOURCE_DIR}/src/video/arm/pixman-arm-neon*.S)
        set(SOURCE_FILES ${SOURCE_FILES} ${ARMNEON_SOURCES})
        set(WARN_ABOUT_ARM_NEON_ASM_MIT TRUE)
      endif()
    endif()

  elseif(MSVC_VERSION GREATER 1500)
    # TODO: SDL_cpuinfo.h needs to support the user's configuration wish
    # for MSVC - right now it is always activated
    if(NOT ARCH_64)
      set(HAVE_MMX TRUE)
      set(HAVE_3DNOW TRUE)
    endif()
    set(HAVE_SSE TRUE)
    set(HAVE_SSE2 TRUE)
    set(HAVE_SSE3 TRUE)
    check_include_file("immintrin.h" HAVE_IMMINTRIN_H)
    set(SDL_ASSEMBLY_ROUTINES 1)
  endif()
endif()

# TODO: Can't deactivate on FreeBSD? w/o LIBC, SDL_stdinc.h can't define
# anything.
if(SDL_LIBC)
  if(WINDOWS AND NOT MINGW)
    set(HAVE_LIBC TRUE)
    foreach(_HEADER stdio.h string.h wchar.h ctype.h math.h limits.h)
      string(TOUPPER "HAVE_${_HEADER}" _UPPER)
      string(REPLACE "." "_" _HAVE_H ${_UPPER})
      set(${_HAVE_H} 1)
    endforeach()
    set(HAVE_SIGNAL_H 1)
    foreach(_FN
            malloc calloc realloc free qsort abs memset memcpy memmove memcmp
            wcslen _wcsdup wcsdup wcsstr wcscmp wcsncmp _wcsicmp _wcsnicmp
            strlen _strrev _strupr _strlwr strchr strrchr strstr itoa _ltoa
            _ultoa strtol strtoul strtoll strtod atoi atof strcmp strncmp
            _stricmp _strnicmp sscanf
            acos acosf asin asinf atan atanf atan2 atan2f ceil ceilf
            copysign copysignf cos cosf exp expf fabs fabsf floor floorf fmod fmodf
            log logf log10 log10f lround lroundf pow powf round roundf scalbn scalbnf
            sin sinf sqrt sqrtf tan tanf trunc truncf)
      string(TOUPPER ${_FN} _UPPER)
      set(HAVE_${_UPPER} 1)
    endforeach()
    if(NOT CYGWIN AND NOT MINGW)
      set(HAVE_ALLOCA 1)
    endif()
    set(HAVE_M_PI 1)
    target_compile_definitions(sdl-build-options INTERFACE "-D_USE_MATH_DEFINES") # needed for M_PI
    set(STDC_HEADERS 1)
  else()
    set(HAVE_LIBC TRUE)
    check_include_file(sys/types.h HAVE_SYS_TYPES_H)
    foreach(_HEADER
            stdio.h stdlib.h stddef.h stdarg.h malloc.h memory.h string.h limits.h float.h
            strings.h wchar.h inttypes.h stdint.h ctype.h math.h iconv.h signal.h libunwind.h)
      string(TOUPPER "HAVE_${_HEADER}" _UPPER)
      string(REPLACE "." "_" _HAVE_H ${_UPPER})
      check_include_file("${_HEADER}" ${_HAVE_H})
    endforeach()

    set(STDC_HEADER_NAMES "stddef.h;stdarg.h;stdlib.h;string.h;stdio.h;wchar.h;float.h")
    check_include_files("${STDC_HEADER_NAMES}" STDC_HEADERS)
    check_type_size("size_t" SIZEOF_SIZE_T)
    check_symbol_exists(M_PI math.h HAVE_M_PI)
    # TODO: refine the mprotect check
    check_c_source_compiles("#include <sys/types.h>
                             #include <sys/mman.h>
                             int main() { }" HAVE_MPROTECT)
    foreach(_FN
            strtod malloc calloc realloc free getenv setenv putenv unsetenv
            qsort abs bcopy memset memcpy memmove memcmp strlen strlcpy strlcat
            _strrev _strupr _strlwr index rindex strchr strrchr strstr strtok_r
            itoa _ltoa _uitoa _ultoa strtol strtoul _i64toa _ui64toa strtoll strtoull
            atoi atof strcmp strncmp _stricmp strcasecmp _strnicmp strncasecmp
            wcscmp _wcsdup wcsdup wcslcat wcslcpy wcslen wcsncmp wcsstr
            wcscasecmp _wcsicmp wcsncasecmp _wcsnicmp
            sscanf vsscanf vsnprintf fopen64 fseeko fseeko64 _Exit
            )
      string(TOUPPER ${_FN} _UPPER)
      set(_HAVEVAR "HAVE_${_UPPER}")
      check_symbol_exists("${_FN}" "${STDC_HEADER_NAMES}" ${_HAVEVAR})
    endforeach()

    check_symbol_exists(sigaction "signal.h" HAVE_SIGACTION)
    check_symbol_exists(setjmp "setjmp.h" HAVE_SETJMP)
    check_symbol_exists(nanosleep "time.h" HAVE_NANOSLEEP)
    check_symbol_exists(sysconf "unistd.h" HAVE_SYSCONF)
    check_symbol_exists(sysctlbyname "sys/types.h;sys/sysctl.h" HAVE_SYSCTLBYNAME)
    check_symbol_exists(getauxval "sys/auxv.h" HAVE_GETAUXVAL)
    check_symbol_exists(elf_aux_info "sys/auxv.h" HAVE_ELF_AUX_INFO)
    check_symbol_exists(poll "poll.h" HAVE_POLL)

    check_library_exists(m pow "" HAVE_LIBM)
    if(HAVE_LIBM)
      set(CMAKE_REQUIRED_LIBRARIES m)
      foreach(_FN
              atan atan2 atanf atan2f ceil ceilf copysign copysignf cos cosf
              exp expf fabs fabsf floor floorf fmod fmodf log logf log10 log10f
              lround lroundf pow powf round roundf scalbn scalbnf sin sinf sqrt
              sqrtf tan tanf acos acosf asin asinf trunc truncf)
        string(TOUPPER ${_FN} _UPPER)
        set(_HAVEVAR "HAVE_${_UPPER}")
        check_symbol_exists("${_FN}" "math.h" ${_HAVEVAR})
      endforeach()
      set(CMAKE_REQUIRED_LIBRARIES)
      if(NOT VITA)
        list(APPEND EXTRA_LIBS m)
      endif()
    endif()

    check_library_exists(iconv iconv_open "" HAVE_LIBICONV)
    if(HAVE_LIBICONV)
      list(APPEND EXTRA_LIBS iconv)
      set(HAVE_ICONV 1)
    else()
      check_library_exists(c iconv_open "" HAVE_BUILTIN_ICONV)
      if(HAVE_BUILTIN_ICONV)
        set(HAVE_ICONV 1)
      endif()
    endif()

    if(NOT APPLE)
      check_include_file(alloca.h HAVE_ALLOCA_H)
      check_symbol_exists(alloca "alloca.h" HAVE_ALLOCA1)
      check_symbol_exists(alloca "stdlib.h" HAVE_ALLOCA2)
      check_symbol_exists(alloca "malloc.h" HAVE_ALLOCA3)
      if(HAVE_ALLOCA1 OR HAVE_ALLOCA2 OR HAVE_ALLOCA3)
        set(HAVE_ALLOCA 1)
      endif()
    else()
      set(HAVE_ALLOCA_H 1)
      set(HAVE_ALLOCA 1)
    endif()

    check_struct_has_member("struct sigaction" "sa_sigaction" "signal.h" HAVE_SA_SIGACTION)
  endif()
else()
  if(WINDOWS)
    set(HAVE_STDARG_H 1)
    set(HAVE_STDDEF_H 1)
  endif()
endif()


# Enable/disable various subsystems of the SDL library
foreach(_SUB ${SDL_SUBSYSTEMS})
  string(TOUPPER ${_SUB} _OPT)
  if(NOT SDL_${_OPT})
    set(SDL_${_OPT}_DISABLED 1)
  endif()
endforeach()
if(SDL_JOYSTICK)
  file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/*.c)
  set(SOURCE_FILES ${SOURCE_FILES} ${JOYSTICK_SOURCES})
endif()
if(SDL_HAPTIC)
  if(NOT SDL_JOYSTICK)
    # Haptic requires some private functions from the joystick subsystem.
    message_error("SDL_HAPTIC requires SDL_JOYSTICK, which is not enabled")
  endif()
endif()


# General SDL subsystem options, valid for all platforms
if(SDL_AUDIO)
  # CheckDummyAudio/CheckDiskAudio - valid for all platforms
  if(SDL_DUMMYAUDIO)
    set(SDL_AUDIO_DRIVER_DUMMY 1)
    file(GLOB DUMMYAUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/dummy/*.c)
    set(SOURCE_FILES ${SOURCE_FILES} ${DUMMYAUDIO_SOURCES})
    set(HAVE_DUMMYAUDIO TRUE)
  endif()
  if(SDL_DISKAUDIO)
    set(SDL_AUDIO_DRIVER_DISK 1)
    file(GLOB DISKAUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/disk/*.c)
    set(SOURCE_FILES ${SOURCE_FILES} ${DISKAUDIO_SOURCES})
    set(HAVE_DISKAUDIO TRUE)
  endif()
endif()

if(UNIX OR APPLE)
  # Relevant for Unix/Darwin only
  set(DYNAPI_NEEDS_DLOPEN 1)
  CheckDLOPEN()
  if(SDL_LOADSO AND HAVE_DLOPEN)
    set(SDL_LOADSO_DLOPEN 1)
    file(GLOB DLOPEN_SOURCES ${SDL2_SOURCE_DIR}/src/loadso/dlopen/*.c)
    set(SOURCE_FILES ${SOURCE_FILES} ${DLOPEN_SOURCES})
    set(HAVE_SDL_LOADSO TRUE)
  endif()