Fix build with Visual Studio's builtin CMake support

For some reason MSVCs integrated CMake doesn't set CMAKE_GENERATOR_PLATFORM
so my CPU arch detection magic in CMakeLists.txt didn't work in that case..
Now (when using MSVC) the CPU architecture (D3_ARCH) is set in
neo/sys/platform.h instead.

neo/CMakeLists.txt

@@ -93,21 +93,9 @@ if(NOT (CMAKE_SYSTEM_PROCESSOR STREQUAL CMAKE_HOST_SYSTEM_PROCESSOR))
 	# special case: cross-compiling, here CMAKE_SYSTEM_PROCESSOR should be correct, hopefully
 	# (just leave cpu at ${CMAKE_SYSTEM_PROCESSOR})
 elseif(MSVC)
-	message(STATUS "CMAKE_GENERATOR_PLATFORM: ${CMAKE_GENERATOR_PLATFORM}")
+	# because all this wasn't ugly enough, it turned out that, unlike standalone CMake, Visual Studio's
-	if(CMAKE_GENERATOR_PLATFORM STREQUAL "Win32")
+	# integrated CMake doesn't set CMAKE_GENERATOR_PLATFORM, so I gave up on guessing the CPU arch here
-		set(cpu "x86")
+	# and moved the CPU detection to MSVC-specific code in neo/sys/platform.h
-	elseif(CMAKE_GENERATOR_PLATFORM STREQUAL "x64")
-		set(cpu "x86_64")
-	elseif(CMAKE_GENERATOR_PLATFORM STREQUAL "ARM")
-		# at least on RPi 32bit, gcc -dumpmachine outputs "arm-linux-gnueabihf",
-		#  so we'll use "arm" there => use the same for 32bit ARM on MSVC
-		set(cpu "arm")
-	elseif(CMAKE_GENERATOR_PLATFORM STREQUAL "ARM64")
-		set(cpu "arm64")
-	else()
-		message(FATAL_ERROR "Unknown Target CPU/platform ${CMAKE_GENERATOR_PLATFORM}")
-	endif()
-	message(STATUS "  => CPU architecture extracted from that: \"${cpu}\"")
 else() # not MSVC and not cross-compiling, assume GCC or clang (-compatible), seems to work for MinGW as well
 	execute_process(COMMAND ${CMAKE_C_COMPILER} "-dumpmachine"
 	                RESULT_VARIABLE cc_dumpmachine_res
@@ -145,8 +133,6 @@ elseif(cpu MATCHES "[aA][rR][mM].*") # some kind of arm..
 	endif()
 endif()
 
-add_definitions(-DD3_ARCH="${cpu}" -DD3_SIZEOFPTR=${CMAKE_SIZEOF_VOID_P})
-
 # target os
 if(APPLE)
 	set(os "macosx")
@@ -154,14 +140,22 @@ else()
 	string(TOLOWER "${CMAKE_SYSTEM_NAME}" os)
 endif()
 
-add_definitions(-DD3_OSTYPE="${os}")
+add_definitions(-DD3_OSTYPE="${os}" -DD3_SIZEOFPTR=${CMAKE_SIZEOF_VOID_P})
 
-message(STATUS "Setting -DD3_ARCH=\"${cpu}\" -DD3_SIZEOFPTR=${CMAKE_SIZEOF_VOID_P} -DD3_OSTYPE=\"${os}\" ")
+if(MSVC)
+	# for MSVC D3_ARCH is set in code (in neo/sys/platform.h)
+	message(STATUS "Setting -DD3_SIZEOFPTR=${CMAKE_SIZEOF_VOID_P} -DD3_OSTYPE=\"${os}\" - NOT setting D3_ARCH, because we're targeting MSVC (VisualC++)")
+	# make sure ${cpu} isn't (cant't be) used by CMake when building with MSVC
+	unset(cpu)
+else()
+	add_definitions(-DD3_ARCH="${cpu}")
+	message(STATUS "Setting -DD3_ARCH=\"${cpu}\" -DD3_SIZEOFPTR=${CMAKE_SIZEOF_VOID_P} -DD3_OSTYPE=\"${os}\" ")
 
-if(cpu MATCHES ".*64.*" AND NOT CMAKE_SIZEOF_VOID_P EQUAL 8)
+	if(cpu MATCHES ".*64.*" AND NOT CMAKE_SIZEOF_VOID_P EQUAL 8)
-	# tough luck if some CPU architecture has "64" in its name but uses 32bit pointers
+		# tough luck if some CPU architecture has "64" in its name but uses 32bit pointers
-	message(SEND_ERROR "CMake thinks sizeof(void*) == 4, but the target CPU looks like a 64bit CPU!")
+		message(SEND_ERROR "CMake thinks sizeof(void*) == 4, but the target CPU ${cpu} looks like a 64bit CPU!")
-	message(FATAL_ERROR "If you're building in a 32bit chroot on a 64bit host, switch to it with 'linux32 chroot' or at least call cmake with linux32 (or your OSs equivalent)!")
+		message(FATAL_ERROR "If you're building in a 32bit chroot on a 64bit host, switch to it with 'linux32 chroot' or at least call cmake with linux32 (or your OSs equivalent)!")
+	endif()
 endif()
 
 # build type
@@ -453,7 +447,9 @@ configure_file(
 	"${CMAKE_BINARY_DIR}/config.h"
 )
 
+if(NOT MSVC)
 message(STATUS "Building ${CMAKE_BUILD_TYPE} for ${os}-${cpu}")
+endif()
 
 if(NOT APPLE AND NOT WIN32)
 	message(STATUS "The install target will use the following directories:")

neo/sys/platform.h

@@ -105,6 +105,35 @@ If you have questions concerning this license or the applicable additional terms
 
 #endif
 
+// Setting D3_ARCH for VisualC++ from CMake doesn't work when using VS integrated CMake
+// so set it in code instead
+#ifdef _MSC_VER
+
+#ifdef D3_ARCH
+  #undef D3_ARCH
+#endif // D3_ARCH
+
+#ifdef _M_X64
+  // this matches AMD64 and ARM64EC (but not regular ARM64), but they're supposed to be binary-compatible somehow, so whatever
+  #define D3_ARCH "x86_64"
+#elif defined(_M_ARM64)
+  #define D3_ARCH "arm64"
+#elif defined(_M_ARM)
+  #define D3_ARCH "arm"
+#elif defined(_M_IX86)
+  #define D3_ARCH "x86"
+#else
+  // if you're not targeting one of the aforementioned architectures,
+  // check https://learn.microsoft.com/en-us/cpp/preprocessor/predefined-macros
+  // to find out how to detect yours and add it here - and please send a patch :)
+  #error "Unknown CPU architecture!"
+  // (for a quick and dirty solution, comment out the previous line, but keep in mind
+  //  that savegames may not be compatible with other builds of dhewm3)
+  #define D3_ARCH "UNKNOWN"
+#endif // _M_X64 etc
+
+#endif // _MSC_VER
+
 
 // Mac OSX
 #if defined(MACOS_X) || defined(__APPLE__)