Finding DirectX12 libraries with CMake and MinGW - c

Question

I am trying to use CMake to find DirectX 12 and link it against an executable. What I have so far works when compiling with MSVC, but fails when compiling with GCC:
Could NOT find D3D12 (missing: D3D12_LIBRARIES).
I am using a slightly altered version of the FindD3D12.cmake:
# Find the win10 SDK path.
if ("$ENV{WIN10_SDK_PATH}$ENV{WIN10_SDK_VERSION}" STREQUAL "" )
get_filename_component(WIN10_SDK_PATH "[HKEY_LOCAL_MACHINE\\SOFTWARE\\WOW6432Node\\Microsoft\\Microsoft SDKs\\Windows\\v10.0;InstallationFolder]" ABSOLUTE CACHE)
get_filename_component(TEMP_WIN10_SDK_VERSION "[HKEY_LOCAL_MACHINE\\SOFTWARE\\WOW6432Node\\Microsoft\\Microsoft SDKs\\Windows\\v10.0;ProductVersion]" ABSOLUTE CACHE)
get_filename_component(WIN10_SDK_VERSION ${TEMP_WIN10_SDK_VERSION} NAME)
elseif(TRUE)
set (WIN10_SDK_PATH $ENV{WIN10_SDK_PATH})
set (WIN10_SDK_VERSION $ENV{WIN10_SDK_VERSION})
endif ("$ENV{WIN10_SDK_PATH}$ENV{WIN10_SDK_VERSION}" STREQUAL "" )
# WIN10_SDK_PATH will be something like C:\Program Files (x86)\Windows Kits\10
# WIN10_SDK_VERSION will be something like 10.0.14393 or 10.0.14393.0; we need the
# one that matches the directory name.
if (IS_DIRECTORY "${WIN10_SDK_PATH}/Include/${WIN10_SDK_VERSION}.0")
set(WIN10_SDK_VERSION "${WIN10_SDK_VERSION}.0")
endif (IS_DIRECTORY "${WIN10_SDK_PATH}/Include/${WIN10_SDK_VERSION}.0")
# Find the d3d12 and dxgi include path, it will typically look something like this.
# C:\Program Files (x86)\Windows Kits\10\Include\10.0.10586.0\um\d3d12.h
# C:\Program Files (x86)\Windows Kits\10\Include\10.0.10586.0\shared\dxgi1_4.h
find_path(
D3D12_INCLUDE_DIR # Set variable D3D12_INCLUDE_DIR
d3d12.h # Find a path with d3d12.h
HINTS "${WIN10_SDK_PATH}/Include/${WIN10_SDK_VERSION}/um"
DOC "path to WIN10 SDK header files"
HINTS
)
find_path(
DXGI_INCLUDE_DIR # Set variable DXGI_INCLUDE_DIR
dxgi1_4.h # Find a path with dxgi1_4.h
HINTS "${WIN10_SDK_PATH}/Include/${WIN10_SDK_VERSION}/shared"
DOC "path to WIN10 SDK header files"
HINTS
)
set(D3D12_INCLUDE_DIRS ${D3D12_INCLUDE_DIR} ${DXGI_INCLUDE_DIR})
# Find D3D libraries
set(D3D12_LIB_NAMES d3d12.lib dxgi.lib d3dcompiler.lib dxguid.lib)
set(D3D12_LIBRARIES)
foreach (D3D12_LIB_NAME ${D3D12_LIB_NAMES})
find_library(${D3D12_LIB_NAME}_LOC NAMES ${D3D12_LIB_NAME} HINTS ${D3D12_HINTS_PATH})
set(D3D12_LIBRARIES ${D3D12_LIBRARIES} ${${D3D12_LIB_NAME}_LOC})
endforeach(D3D12_LIB_NAME)
include(FindPackageHandleStandardArgs)
# handle the QUIETLY and REQUIRED arguments and set D3D12_FOUND to TRUE
# if all listed variables are TRUE
find_package_handle_standard_args(
D3D12 DEFAULT_MSG
D3D12_INCLUDE_DIRS D3D12_LIBRARIES
)
mark_as_advanced(D3D12_INCLUDE_DIRS D3D12_LIBRARIES)
And then linking it with: target_link_libraries(<name> ${D3D12_LIBRARIES}).
The D3D12_INCLUDE_DIRS variable is set to the correct value, the problem is only with the libraries.
Are the DirectX 12 libraries not compatible with GCC and CMake is smart enough to figure that out, or am I doing something wrong when trying to find them?
Edit:
As the answer mentioned, the FindD3D12.cmake module is not needed. The DirectX libraries are system libraries when compiling on Windows, so doing target_link_libraries(<name> PRIVATE d3d12.lib dxgi.lib d3dcompiler.lib dxguid.lib) works.

Answer 1

======================================================
Windows:
DirectX is part of the Windows SDK.
If you have are compiling on Windows there is no way you aren't using the SDK to compile. Therefor don't worry about handling the include directories and whatnot.
Therefore you can treat the Directx libraries as regular system libraries and the following command will work. That's the magic of cmake.
So most of your cmake isn't really necessary. At least if you are using visual studio.
If you aren't using visual studio you might need to write up a toolchain (https://cmake.org/cmake/help/latest/manual/cmake-toolchains.7.html?highlight=cmake_cxx_compiler_id#cmake-toolchains-7)
# DX12 libraries
target_link_libraries(foobar PRIVATE
d3d12.lib
dxgi.lib
dxguid.lib
)
======================================================
Linux:
Secondly DirectX12 will have linux support:
https://devblogs.microsoft.com/directx/directx-heart-linux/
However I don't think it allows use of graphics functionality, just the compute functionality. But regardless assuming Microsoft didn't make it extremely painful the cmake should be roughly similar.
======================================================
Lastly if you wanna know what version of the SDK you are building against check out CMAKE_SYSTEM_VERSION
On windows setting this before the first project call sets the SDK version. Because that's what the SDK versions stand for. Versions of windows builds.
Also to be extra cautious add extra static_asserts in your codebase to make sure you are using a version of the SDK you intended you'll want to include "Windows.h" which you probably already have anyway. And then check for the compiler definitions that tell you what Version of the Windows OS you are compiling.
"When you use the Windows SDK, you can specify which versions of Windows your code can run on. The preprocessor macros WINVER and _WIN32_WINNT specify the minimum operating system version your code supports. Visual Studio and the Microsoft C++ compiler support targeting Windows 7 SP1 and later. Older toolsets include support for Windows XP SP2, Windows Server 2003 SP1, Vista, and Windows Server 2008. Windows 95, Windows 98, Windows ME, Windows NT, and Windows 2000 are unsupported." - Microsoft Documentation (https://learn.microsoft.com/en-us/cpp/porting/modifying-winver-and-win32-winnt?view=msvc-160)

Answer 2

Are the DirectX 12 libraries not compatible with GCC
Every compiler has its own library format, cl uses .lib libraries and gcc uses .a and .so libraries. You can't just take cl's libraries (which is what is stored in the Windows SDK) and feed them to gcc.