[CMake] Support for Custom LANG in CMAKE (CUDA and general case)

[Łukasz Tasz]

>
> I don't understand what you mean by partially.  If you had
> cuda_add_executable(demo main.cxx demo1.cu demo2.cu), then main.cxx will be
> compiled by the host compiler, demo1.cu  and demo2.cu will be compiled by
> nvcc (CUDA + host compiler), and then all will be linked by the host linker.
>
In this case I need to agree with you. But I would still vote to have
transparency, provide common interface to developers. From my
perspective cuda is the same compiler like c++, that's why I would
vote to provide the same interface like for CXX or C.

>
> The problem with dependencies I think relates to how the build system
> represents them.  In makefiles the dependencies are explicitly defined,
> while in Visual Studio the dependencies for C code is handled by the IDE and
> other files are explicit.  It seems like a lot of effort to extend CMake
> dependency scanning capabilities when this functionality can only be
> extended to makefiles.  Is this what you are desiring?

As far as I correctly understood patch from Peter, implementation for
makefile dependency is on place.
For me makefile dependency is fine, since I'm using only makefiles.

I just tried to understand idea of LANGUAGE inside cmake. I think that
in this particular case having new language on place is really good
idea. This is what for language was.

regards
Lukasz


-- 
Lukasz Tasz