Regression: DirectXTK no longer is able to generate project using certain configurations

[joshuamaiche]

Summary

Previously, DirectXTK supported clang-cl in visual studio, using CMake with CMakePresets.json. Now, the project can't be generated due to a missing symbol (DIRECTX_ARCH).

Setup

Folder Structure

repro_folder
  - CMakePresets.json
  - CMakeLists.txt

CMakePresets.json

{
    "version": 4,

    "configurePresets": [
        {
            "name": "msvc",
            "displayName": "MSVC",
            "cacheVariables": { "CMAKE_CXX_COMPILER": "cl.exe" },
            "architecture": { "value": "x64", "strategy": "external" }
        },
        {
            "name": "clang",
            "displayName": "Clang",
            "cacheVariables": { "CMAKE_CXX_COMPILER": "clang-cl" },
            "architecture": { "value": "x64", "strategy": "external" }
        }
    ]
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.24)

include(FetchContent)

project(repro LANGUAGES CXX)

FetchContent_Declare(
    DirectXTK
    GIT_REPOSITORY https://github.com/Microsoft/DirectXTK.git
    GIT_TAG main
    OVERRIDE_FIND_PACKAGE
)

FetchContent_MakeAvailable(DirectXTK)

Repro

• Ensure Visual Studio is using presets.json (Tools > Options > CMake > General >CMake configuration file: > Always use CMake Presets)
• Open Visual Studio
• Select Open a local folder
• Open repro_folder
• Select MSVC configuration. Generate project (can be triggered by re-saving CMakeLists.txt). Notice the generation succeeds.
• Select Clang configuration. Generate project. Notice the generation fails.

Error message

1> [CMake] CMake Error at out/build/clang/_deps/directxtk-src/build/CompilerAndLinker.cmake:215 (if):
1> [CMake]   if given arguments:
1> [CMake] 
1> [CMake]     "STREQUAL" "x64"
1> [CMake] 
1> [CMake]   Unknown arguments specified
1> [CMake] Call Stack (most recent call first):
1> [CMake]   out/build/clang/_deps/directxtk-src/CMakeLists.txt:66 (include)
1> [CMake] -- Configuring incomplete, errors occurred!

Misc

This error is caused by DIRECTX_ARCH not being set. When debugging why, I saw that with the Clang configuration, both CMAKE_GENERATOR_PLATFORM and CMAKE_VS_PLATFORM_NAME_DEFAULT seem to be blank. This regression was introduced when the code coverage change was added a month ago (270d2e7). Using a prior commit allows the project to be generated.