runtimes: added check_compile to detect libpfm4-dev

[liamsemeria]

Motivation:
xtc wasn't working without it installed because of perfmon includes in the runtime.

[ElectrikSpace]

I think we need to fix #43 first.
New CPUs are not necessarily supported by the distributed versions of libpfm4-dev on stable linux distros.

[qaco]

I think we need to fix #43 first. New CPUs are not necessarily supported by the distributed versions of libpfm4-dev on stable linux distros.

Ok could you open a PR for #43 (with an explicit error message) ?

[guillon]

@liamsemeria Can you add the motivation, use case for this PR in the description?

Originally, I wanted to have the least set of dependencies for XTC to work, i.e. if not installed/available the hw counter just return 0.

Do you think there would be a motivation to change this?

[liamsemeria]

@guillon I updated the motivation. When installing xtc on my computer, I'm pretty sure none of the tests were passing without it installed, and simple xtc examples weren't working.

[guillon]

@liamsemeria ok, I understand. I think that th problem comes from the fact that one may have:

• libpfm4 installed
• bit not libpfm4-dev
  In this case, I guess that XTC detects the library, but as the includes are not installed, it fails.

So basically, what is wrong:

• we should not detect the presence of libpfm4-dev by a library query only, but also by a test-compile including the header
  We could:
• add in utils/... a function to test the correct compilation of a .c file (with optional libraries)
• use it to check for a correctly installed libpfm4-dev with something like: has_pfm4 = check_compile("#include <...>\nint main() { return 0; }\n", libs="pfm4")

Do you think you could contribute this?

[liamsemeria]

@guillon Yeah I can. Seems like I would then use that similar to has_pfm in src/xtc/runtimes/host/runtime.py

[guillon]

@guillon I updated the motivation. When installing xtc on my computer, I'm pretty sure none of the tests were passing without it installed, and simple xtc examples weren't working.

Yes, as explained what I did there was not actually sufficient to detect a "dev" package, you need to test the presence of the lib and of the include files.

[liamsemeria]

@guillon I added the check_compile, it fixed the issue and all tests pass independent of whether or not a libpfm4 is installed/

[liamsemeria]

@guillon fixed the double import

[guillon]

Thanks a lot for this change! Great