CMake check for mismatch of toolset and arch setting

Author: walbourn

build/CompilerAndLinker.cmake

@@ -45,6 +45,17 @@ else()
     set(DIRECTX_HOST_ARCH x64)
 endif()
 
+#--- Check DIRECTX_ARCH value
+if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+    if(DIRECTX_ARCH MATCHES "x86|^arm$")
+      message(FATAL_ERROR "64-bit toolset mismatch detected for DIRECTX_ARCH setting")
+    endif()
+elseif(CMAKE_SIZEOF_VOID_P EQUAL 4)
+    if(DIRECTX_ARCH MATCHES "x64|arm64")
+      message(FATAL_ERROR "32-bit toolset mismatch detected for DIRECTX_ARCH setting")
+    endif()
+endif()
+
 #--- Build with Unicode Win32 APIs per "UTF-8 Everywhere"
 if(WIN32)
   list(APPEND COMPILER_DEFINES _UNICODE UNICODE)
@@ -166,10 +177,7 @@ elseif(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
       list(APPEND COMPILER_SWITCHES /Zc:lambda)
     endif()
 
-    if((CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 19.29)
-       AND (NOT VCPKG_TOOLCHAIN))
-      list(APPEND COMPILER_SWITCHES /external:W4)
-    endif()
+    # GDKX scenarios can't use external:W4
 
     if((CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 19.31)
        AND (XBOX_CONSOLE_TARGET STREQUAL "durango"))