Merge pull request #771 from Azaezel/alpha40/macCompile

correct mac compilation

Engine/source/platformPOSIX/POSIXFileio.cpp

@@ -46,6 +46,9 @@
 #if defined(__FreeBSD__)
 #include <sys/types.h>
 #endif
+#if defined(__APPLE__)
+#include <sys/syslimits.h>
+#endif
 #include <utime.h>
 
 /* these are for reading directors, getting stats, etc. */

Tools/CMake/basics.cmake

@@ -467,6 +467,19 @@ if(WIN32)
         ENDFOREACH()
     endif()
 else()
+    if(${CMAKE_VERSION} VERSION_LESS "3.16.0")
+        macro(CHECK_OBJC_SOURCE_COMPILES SOURCE VAR)
+            set(PREV_REQUIRED_DEFS "${CMAKE_REQUIRED_DEFINITIONS}")
+            set(CMAKE_REQUIRED_DEFINITIONS "-x objective-c ${PREV_REQUIRED_DEFS}")
+            CHECK_C_SOURCE_COMPILES(${SOURCE} ${VAR})
+            set(CMAKE_REQUIRED_DEFINITIONS "${PREV_REQUIRED_DEFS}")
+        endmacro()
+    else()
+        include(CheckOBJCSourceCompiles)
+        if (APPLE)
+            enable_language(OBJC)
+        endif()
+    endif()
     # TODO: improve default settings on other platforms
     set(TORQUE_CXX_FLAGS_EXECUTABLES "" CACHE STRING "")
     mark_as_advanced(TORQUE_CXX_FLAGS_EXECUTABLES)