[CMake] Merging gcc unit tests into a TI DSP crosscompiler build system

[Alexander Neundorf]

On Monday 08 November 2010, Wojciech Migda wrote:
> Hi,
>
> in our company we have a robust cmake-based build system which utilizes TI
> DSP cgtools compiler. Aside from that we are developing gcc-based unit
> tests (CxxTest coupled with CMake/CTest/CDash combo). We are considering
> merging the latter into the former, but we kind of don't even know how to
> put them together so that two C/C++ compilers can coexist in a single CMake
> build system. I tried inserting ADD_SUBDIRECTORY pointing to one of the
> test suites CMakeLists.txt file into the main CMakeLists.txt of the core
> build system but it blows everything up.
>
> Has anyone attempted this kind of configuration already ? Is it achievable
> with CMake at all ?

It is  probably possible, but it's a hack.
In general, you can only have one compiler per language in one cmake build 
tree.
Among other because the results of configure checks are compiler-specific, and 
they are saved in the global cache, so you can't have multiple correct 
values.

What can be done, is to change the CMAKE_C_COMPILER etc. variables in a 
subdir, then those changed settings will be used there.
If you use additional stuff like find_package() etc. you must be sure you know 
what you are doing, so that it doesn't conflict with other (global) cache 
variables in your project.

Alex