sdl2-compat: cmake: port over sdlplatform.cmake from SDL3

From f2083e7c758b18878c083d604d46ccb686ba51b6 Mon Sep 17 00:00:00 2001
From: Anonymous Maarten <[EMAIL REDACTED]>
Date: Sun, 6 Aug 2023 20:51:54 +0200
Subject: [PATCH] cmake: port over sdlplatform.cmake from SDL3

---
 cmake/sdlplatform.cmake | 129 ++++++++++++++++++++++++++++------------
 1 file changed, 90 insertions(+), 39 deletions(-)

diff --git a/cmake/sdlplatform.cmake b/cmake/sdlplatform.cmake
index f55ad31..ebb2077 100644
--- a/cmake/sdlplatform.cmake
+++ b/cmake/sdlplatform.cmake
@@ -2,54 +2,105 @@ macro(SDL_DetectCMakePlatform)
   set(SDL_CMAKE_PLATFORM )
   # Get the platform
   if(WIN32)
-    set(SDL_CMAKE_PLATFORM WINDOWS)
-  elseif(UNIX AND NOT APPLE)
-    if(CMAKE_SYSTEM_NAME MATCHES ".*Linux")
-      set(SDL_CMAKE_PLATFORM LINUX)
-    elseif(CMAKE_SYSTEM_NAME MATCHES "kFreeBSD.*")
-      set(SDL_CMAKE_PLATFORM FREEBSD)
-    elseif(CMAKE_SYSTEM_NAME MATCHES "kNetBSD.*|NetBSD.*")
-      set(SDL_CMAKE_PLATFORM NETBSD)
-    elseif(CMAKE_SYSTEM_NAME MATCHES "kOpenBSD.*|OpenBSD.*")
-      set(SDL_CMAKE_PLATFORM OPENBSD)
-    elseif(CMAKE_SYSTEM_NAME MATCHES ".*GNU.*")
-      set(SDL_CMAKE_PLATFORM GNU)
-    elseif(CMAKE_SYSTEM_NAME MATCHES ".*BSDI.*")
-      set(SDL_CMAKE_PLATFORM BSDI)
-    elseif(CMAKE_SYSTEM_NAME MATCHES "DragonFly.*|FreeBSD")
-      set(SDL_CMAKE_PLATFORM FREEBSD)
-    elseif(CMAKE_SYSTEM_NAME MATCHES "SYSV5.*")
-      set(SDL_CMAKE_PLATFORM SYSV5)
-    elseif(CMAKE_SYSTEM_NAME MATCHES "Solaris.*|SunOS.*")
-      set(SDL_CMAKE_PLATFORM SOLARIS)
-    elseif(CMAKE_SYSTEM_NAME MATCHES "HP-UX.*")
-      set(SDL_CMAKE_PLATFORM HPUX)
-    elseif(CMAKE_SYSTEM_NAME MATCHES "AIX.*")
-      set(SDL_CMAKE_PLATFORM AIX)
-    elseif(CMAKE_SYSTEM_NAME MATCHES "Minix.*")
-      set(SDL_CMAKE_PLATFORM MINIX)
-    endif()
+    set(SDL_CMAKE_PLATFORM Windows)
+  elseif(PSP)
+    set(SDL_CMAKE_PLATFORM psp)
   elseif(APPLE)
     if(CMAKE_SYSTEM_NAME MATCHES ".*Darwin.*")
-      set(SDL_CMAKE_PLATFORM DARWIN)
+      set(SDL_CMAKE_PLATFORM Darwin)
     elseif(CMAKE_SYSTEM_NAME MATCHES ".*MacOS.*")
-      set(SDL_CMAKE_PLATFORM MACOSX)
+      set(SDL_CMAKE_PLATFORM MacosX)
     elseif(CMAKE_SYSTEM_NAME MATCHES ".*tvOS.*")
-      set(SDL_CMAKE_PLATFORM TVOS)
+      set(SDL_CMAKE_PLATFORM tvOS)
     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(SDL_CMAKE_PLATFORM IOS)
-      endif()
+      set(SDL_CMAKE_PLATFORM iOS)
     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(SDL_CMAKE_PLATFORM HAIKU)
+    set(SDL_CMAKE_PLATFORM Haiku)
   elseif(NINTENDO_3DS)
-    set(SDL_CMAKE_PLATFORM N3DS)
+    set(SDL_CMAKE_PLATFORM n3ds)
+  elseif(PS2)
+    set(SDL_CMAKE_PLATFORM ps2)
+  elseif(VITA)
+    set(SDL_CMAKE_PLATFORM Vita)
+  elseif(CMAKE_SYSTEM_NAME MATCHES ".*Linux")
+    set(SDL_CMAKE_PLATFORM Linux)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "kFreeBSD.*")
+    set(SDL_CMAKE_PLATFORM FreeBSD)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "kNetBSD.*|NetBSD.*")
+    set(SDL_CMAKE_PLATFORM NetBSD)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "kOpenBSD.*|OpenBSD.*")
+    set(SDL_CMAKE_PLATFORM OpenBSD)
+  elseif(CMAKE_SYSTEM_NAME MATCHES ".*GNU.*")
+    set(SDL_CMAKE_PLATFORM GNU)
+  elseif(CMAKE_SYSTEM_NAME MATCHES ".*BSDI.*")
+    set(SDL_CMAKE_PLATFORM BSDi)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "DragonFly.*|FreeBSD")
+    set(SDL_CMAKE_PLATFORM FreeBSD)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "SYSV5.*")
+    set(SDL_CMAKE_PLATFORM SYSV5)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "Solaris.*|SunOS.*")
+    set(SDL_CMAKE_PLATFORM Solaris)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "HP-UX.*")
+    set(SDL_CMAKE_PLATFORM HPUX)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "AIX.*")
+    set(SDL_CMAKE_PLATFORM AIX)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "Minix.*")
+    set(SDL_CMAKE_PLATFORM Minix)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "Android.*")
+    set(SDL_CMAKE_PLATFORM Android)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "Emscripten.*")
+    set(SDL_CMAKE_PLATFORM Emscripten)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "QNX.*")
+    set(SDL_CMAKE_PLATFORM QNX)
+  elseif(CMAKE_SYSTEM_NAME MATCHES "BeOS.*")
+    message(FATAL_ERROR "BeOS support has been removed as of SDL 2.0.2.")
   endif()
+
   if(SDL_CMAKE_PLATFORM)
-    set(${SDL_CMAKE_PLATFORM} TRUE)
+    string(TOUPPER "${SDL_CMAKE_PLATFORM}" _upper_platform)
+    set(${_upper_platform} TRUE)
+  else()
+    set(SDL_CMAKE_PLATFORM} "unknown")
   endif()
 endmacro()
+
+function(SDL_DetectCPUArchitecture)
+  set(sdl_cpu_names)
+  if(APPLE AND CMAKE_OSX_ARCHITECTURES)
+    foreach(osx_arch ${CMAKE_OSX_ARCHITECTURES})
+      if(osx_arch STREQUAL "x86_64")
+        list(APPEND sdl_cpu_names "x64")
+      elseif(osx_arch STREQUAL "arm64")
+        list(APPEND sdl_cpu_names "arm64")
+      endif()
+    endforeach()
+  endif()
+
+  set(sdl_known_archs x64 x86 arm64 arm32 emscripten powerpc64 powerpc32 loongarch64)
+  if(NOT sdl_cpu_names)
+    set(found FALSE)
+    foreach(sdl_known_arch ${sdl_known_archs})
+      if(NOT found)
+        string(TOUPPER "${sdl_known_arch}" sdl_known_arch_upper)
+        set(var_name "SDL_CPU_${sdl_known_arch_upper}")
+        check_cpu_architecture(${sdl_known_arch} ${var_name})
+        if(${var_name})
+          list(APPEND sdl_cpu_names ${sdl_known_arch})
+          set(found TRUE)
+        endif()
+      endif()
+    endforeach()
+  endif()
+
+  foreach(sdl_known_arch ${sdl_known_archs})
+    string(TOUPPER "${sdl_known_arch}" sdl_known_arch_upper)
+    set(var_name "SDL_CPU_${sdl_known_arch_upper}")
+    if(sdl_cpu_names MATCHES "(^|;)${sdl_known_arch}($|;)")  # FIXME: use if(IN_LIST)
+      set(${var_name} 1 PARENT_SCOPE)
+    else()
+      set(${var_name} 0 PARENT_SCOPE)
+    endif()
+  endforeach()
+  set(SDL_CPU_NAMES ${sdl_cpu_names} PARENT_SCOPE)
+endfunction()