Make OpenCL an optional dependency about hwinfo

[lfreist]

Hi, valid point! I'll check the options and will change how OpenCL is added.

[barracuda156]

Yes, please. At the moment it does not work correctly at all:

CMake Error at external/miss-opencl/CMakeLists.txt:22 (add_subdirectory):
  The source directory

    /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_devel_hwinfo/hwinfo/work/hwinfo-a1ae945ab784780af5fc166150a6f6612d41e7bf/external/miss-opencl/external/OpenCL

  does not contain a CMakeLists.txt file.


-- Configuring incomplete, errors occurred!

[lfreist]

You need to run git update --init --recursive first. However, building on Mac has some issues atm since I do not have access to a Mac...

[diiigle]

This OpenCL repo does have another downside (for your users) which you might be not aware of:

fatal: clone of 'https://github.com/throwtheswitch/cexception.git' into submodule path 'C:/Users/myname/repositories/my-looongish-repo-name/ext/hwinfo/external/miss-opencl/external/OpenCL/external/OpenCL-CLHPP/external/CMock/vendor/c_exception' failed
Failed to clone 'vendor/c_exception'. Retry scheduled
Cloning into 'C:/Users/myname/repositories/my-looongish-repo-name/ext/hwinfo/external/miss-opencl/external/OpenCL/external/OpenCL-CLHPP/external/CMock/vendor/c_exception'...
fatal: cannot write keep file 'C:/Users/myname/repositories/my-looongish-repo-name/.git/modules/ext/hwinfo/modules/external/miss-opencl/modules/external/OpenCL/modules/headers-cpp/modules/external/CMock/modules/vendor/c_exception/objects/pack/pack-fd8baa50a07a4317443b1e3b5520f09f92fa84cf.keep': Filename too long

The submodules are nested so deep, that some filenames run out of MAX_PATH=260 on Windows. I can't even clone my own repo any more because of that unless I go to C:\tmp\ or something.

Fruit for thought, if OpenCL isn't a bit of an overkill.

Edit:
git -c submodule."external/miss-opencl".update=none submodule update --init --recursive seems to be a workaround for now. https://stackoverflow.com/a/52185169

[lfreist]

Yes, OpenCL kind of is an overkill, but for now, I found no other way to retrieve GPU Memory information...