CMAKE_OSX_ARCHITECTURES for MacOS cross compilation

CMakeLists.txt

@@ -850,7 +850,8 @@ endif()
 
 set(ARCH_FLAGS "")
 
-if ((${CMAKE_SYSTEM_PROCESSOR} MATCHES "arm") OR (${CMAKE_SYSTEM_PROCESSOR} MATCHES "aarch64") OR ("${CMAKE_GENERATOR_PLATFORM_LWR}" MATCHES "arm64"))
+if ((APPLE AND CMAKE_OSX_ARCHITECTURES AND ("${CMAKE_OSX_ARCHITECTURES}" MATCHES "arm64")) OR
+    (((APPLE AND NOT CMAKE_OSX_ARCHITECTURES) OR NOT APPLE) AND (("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "arm") OR ("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "aarch64") OR ("${CMAKE_GENERATOR_PLATFORM_LWR}" MATCHES "arm64"))))
     message(STATUS "ARM detected")
     if (MSVC)
         add_compile_definitions(__ARM_NEON)
@@ -876,7 +877,8 @@ if ((${CMAKE_SYSTEM_PROCESSOR} MATCHES "arm") OR (${CMAKE_SYSTEM_PROCESSOR} MATC
             list(APPEND ARCH_FLAGS -mno-unaligned-access)
         endif()
     endif()
-elseif (${CMAKE_SYSTEM_PROCESSOR} MATCHES "^(x86_64|i686|AMD64)$" OR "${CMAKE_GENERATOR_PLATFORM_LWR}" MATCHES "^(x86_64|i686|amd64|x64)$" )
+elseif ((APPLE AND CMAKE_OSX_ARCHITECTURES AND ("${CMAKE_OSX_ARCHITECTURES}" MATCHES "x86_64")) OR
+    (((APPLE AND NOT CMAKE_OSX_ARCHITECTURES) OR NOT APPLE) AND ("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "^(x86_64|i686|AMD64)$" OR "${CMAKE_GENERATOR_PLATFORM_LWR}" MATCHES "^(x86_64|i686|amd64|x64)$" )))
     message(STATUS "x86 detected")
     if (MSVC)
         # instruction set detection for MSVC only