CMake module not automatically setting build and MSVC runtime type

[CoffeeFlux]

When building cURL as a CMake subproject on Windows with MSVC, I was running into linker errors with the VC runtime. It appears the larger Meson project's settings regarding the build type and b_vscrt are not passed down, so if the CMake subproject builds debug by default and the higher-level project is release or debugoptimized, you will be trying to link against two different versions of the runtime.

In my case, I can solve this by just setting MSVC_RUNTIME_LIBRARY or CMAKE_BUILD_TYPE (which will then default to the optimized runtime). I opted for the latter and now it links correctly, but I wanted to see if not propagating this is intentional or not. If it is, it might be worth mentioning this in the documentation, as I would not have guessed that it would be a problem.

Meson version: 0.56.0
CMake version: 3.19.0

How I'm invoking the CMake module: https://github.com/TypesettingTools/ffi-experiments/blob/3b9efd7a8b4e93386e0bcbe84acf33a7a9ef8615/meson.build#L16-L41

[mensinda]

Doing this internally should be possible.

In the meantime, setting either of the two CMake variables (preferably in a cross or native file using the new [cmake] section) would be the way to go.

[szanni]

Confirmed. The issue still presents itself for:

• meson 0.64.0
• cmake 3.24.0

I would consider this to be a bug though, not an enhancement.

Linking fails miserably otherwise and the error message is sadly not terribly helpful.

The other setting that does not get passed down is b_staticpic. Happy to open another issue (probably one already exists).

The following did the trick for me, the project I am using does not have a well formed CMakeList.txt like curl:

cmake = import('cmake')
cmake_opts = cmake.subproject_options()
cmake_opts.add_cmake_defines({
  'CMAKE_POSITION_INDEPENDENT_CODE': true,
  'CMAKE_MSVC_RUNTIME_LIBRARY': 'MultiThreaded',
  'CMAKE_BUILD_TYPE': 'Release'
})

mylib_proj = cmake.subproject('mylib', options : cmake_opts)
mylib_dep = libsamplerate_proj.dependency('mylib')