CMake configuration fails with MSBuild as the generator because of empty 'CMAKE_BUILD_TYPE'

[asklar]

I actually wasn't able to get the repo building anymore using the instructions in the README... CMAKE_BUILD_TYPE seems to evaluate to empty string even though I call init_all / init.cmd with the right params. Perhaps something is out of sync in the readme?

Originally posted by @asklar in #317 (comment)

[dunhor]

Can you share what commands you ran and the outputs you got?

[asklar]

F:\wil> scripts\init.cmd -c msvc -g msbuild
The system cannot find the drive specified.
The system cannot find the drive specified.
Using compiler....... msvc
Using architecture... x64
Using build type..... debug
Using build root..... F:\wil\build\msvc64debug

-- Building for: Visual Studio 17 2022
-- Selecting Windows SDK version 10.0.25300.0 to target Windows 10.0.
-- The C compiler identification is MSVC 19.35.32215.0
-- The CXX compiler identification is MSVC 19.35.32215.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: F:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Tools/MSVC/14.35.32215/bin/Hostx64/x64/cl.exe - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: F:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Tools/MSVC/14.35.32215/bin/Hostx64/x64/cl.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
Feeds used:
  C:\Users\asklar\.nuget\packages\
  https://api.nuget.org/v3/index.json
  C:\Program Files (x86)\Microsoft SDKs\NuGetPackages\
  C:\temp



Attempting to gather dependency information for package 'Microsoft.Windows.CppWinRT.2.0.221121.5' with respect to project 'F:\wil\build\msvc64debug\packages', targeting 'Any,Version=v0.0'
Gathering dependency information took 258 ms
Attempting to resolve dependencies for package 'Microsoft.Windows.CppWinRT.2.0.221121.5' with DependencyBehavior 'Lowest'
Resolving dependency information took 0 ms
Resolving actions to install package 'Microsoft.Windows.CppWinRT.2.0.221121.5'
Resolved actions to install package 'Microsoft.Windows.CppWinRT.2.0.221121.5'
Retrieving package 'Microsoft.Windows.CppWinRT 2.0.221121.5' from 'C:\Users\asklar\.nuget\packages\'.
Adding package 'Microsoft.Windows.CppWinRT.2.0.221121.5' to folder 'F:\wil\build\msvc64debug\packages'
Added package 'Microsoft.Windows.CppWinRT.2.0.221121.5' to folder 'F:\wil\build\msvc64debug\packages'
Successfully installed 'Microsoft.Windows.CppWinRT 2.0.221121.5' to F:\wil\build\msvc64debug\packages
Executing nuget actions took 453 ms
CMake Error at tests/CMakeLists.txt:44 (if):
  if given arguments:

    "STREQUAL" "RelWithDebInfo"

  Unknown arguments specified


-- Configuring incomplete, errors occurred!
See also "F:/wil/build/msvc64debug/CMakeFiles/CMakeOutput.log".

[dunhor]

Thanks! Looks like this is as I suspected.

Your original comment suggested that you were getting errors with the init_all.cmd script - is that still the case?

[asklar]

yes, init-all fails for me because I don't have/use clang :)

[dunhor]

Gotcha. So, in that case, it sounds like this should just be scoped down to running init.cmd with MSBuild as the generator

[citelao]

I have a mitigation for this---

Wrap the if conditions that check CMAKE_BUILD_TYPE (on ~line 45 and ~75) in checks for Clang:

if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
    # For some unknown reason, 'RelWithDebInfo' compiles with '/Ob1' as opposed to '/Ob2' which prevents inlining of
    # functions not marked 'inline'. The reason we prefer 'RelWithDebInfo' over 'Release' is to get debug info, so manually
    # revert to the desired (and default) inlining behavior as that exercises more interesting code paths
    if (${CMAKE_BUILD_TYPE} STREQUAL "RelWithDebInfo")
        # TODO: This is currently blocked by an apparent Clang bug: https://github.com/llvm/llvm-project/issues/59690
        # replace_cxx_flag("/Ob1" "/Ob2")
    endif() 
endif()

if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
    if (${CMAKE_BUILD_TYPE} STREQUAL "Debug")
        set(DEBUG_BUILD TRUE)
        set(HAS_DEBUG_INFO TRUE)
    elseif(${CMAKE_BUILD_TYPE} STREQUAL "RelWithDebInfo")
        set(HAS_DEBUG_INFO TRUE)
    endif()
endif()

This is probably not the correct approach (CMAKE_BUILD_TYPE should probably have a value during msbuild), but it unblocked me.

[dunhor]

This is probably not the correct approach

Right. The problem is not with the target compiler, but with the target generator. MSVC+Ninja works correctly; it's only when using MSBUILD as the generator that this issue presents itself

[HO-COOH]

Encountered the same issue. The temporary workaround for me is to just open visual studio under wil folder, and set the CMAKE_TOOLCHAIN_FILE in the cmake configuration gui inside visual studio.

[oold]

CMAKE_BUILD_TYPE should probably have a value during msbuild

Not when using a multi-config generator. It is always empty for those.

CMake docs:

Specifies the build type on single-configuration generators (e.g. Makefile Generators or Ninja).

The MSBuild generator is a multi-config generator. You select the configuration at build-time, so that's after CMake has already run the commands from the list file. CMAKE_BUILD_TYPE can't have a meaningful value at configuration-time. It wouldn't make sense. What would happen if you specify Debug during configuration and select Release when building?

I guess the compiler flags variable might be empty too in that case. There's this for config-specific flags. That could be the right place to check for a fix.