Thanks for your reply, i re-run the commands using -DCMAKE_C_COMPILER instead of -DCC, these are the relevant output lines.
It now indeed seems to distinguish between CMAKE_CXX_COMPILER_FRONTEND_VARIANT: GNU for
clang and CMAKE_CXX_COMPILER_FRONTEND_VARIANT: MSVC for clang-cl.
So I guess this is the variable that i should be looking at, right?
cmake .. -G "Visual Studio 16 2019"
-- Selecting Windows SDK version 10.0.18362.0 to target Windows 10.0.19042.
-- The C compiler identification is MSVC 19.28.29914.0
-- The CXX compiler identification is MSVC 19.28.29914.0
-- Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.28.29910/bin/Hostx64/x64/cl.exe - skipped
-- Check for working CXX compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.28.29910/bin/Hostx64/x64/cl.exe - skipped
CMAKE_CXX_COMPILER_ID: MSVC
CMAKE_CXX_SIMULATE_ID:
CMAKE_CXX_COMPILER_FRONTEND_VARIANT:
cmake .. -G "Visual Studio 16 2019" -T ClangCL
-- Selecting Windows SDK version 10.0.18362.0 to target Windows 10.0.19042.
-- The C compiler identification is Clang 11.0.0 with MSVC-like command-line
-- The CXX compiler identification is Clang 11.0.0 with MSVC-like command-line
-- Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/Llvm/x64/bin/clang-cl.exe - skipped
-- Check for working CXX compiler: C:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/Llvm/x64/bin/clang-cl.exe - skipped
CMAKE_CXX_COMPILER_ID: Clang
CMAKE_CXX_SIMULATE_ID: MSVC
CMAKE_CXX_COMPILER_FRONTEND_VARIANT: MSVC
cmake .. -G Ninja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang
-- The C compiler identification is Clang 12.0.0 with GNU-like command-line
-- The CXX compiler identification is Clang 12.0.0 with GNU-like command-line
-- Check for working C compiler: C:/Program Files/LLVM/bin/clang.exe - skipped
-- Check for working CXX compiler: C:/Program Files/LLVM/bin/clang.exe - skipped
CMAKE_CXX_COMPILER_ID: Clang
CMAKE_CXX_SIMULATE_ID: MSVC
CMAKE_CXX_COMPILER_FRONTEND_VARIANT: GNU
cmake .. -G Ninja -DCMAKE_C_COMPILER=clang-cl -DCMAKE_CXX_COMPILER=clang-cl
-- The C compiler identification is Clang 12.0.0 with MSVC-like command-line
-- The CXX compiler identification is Clang 12.0.0 with MSVC-like command-line
-- Check for working C compiler: C:/Program Files/LLVM/bin/clang-cl.exe - skipped
-- Check for working CXX compiler: C:/Program Files/LLVM/bin/clang-cl.exe - skipped
CMAKE_CXX_COMPILER_ID: Clang
CMAKE_CXX_SIMULATE_ID: MSVC
CMAKE_CXX_COMPILER_FRONTEND_VARIANT: MSVC