[PWGHF] runMassFitter: add main() function and missing header, provide Readme

[lubynets]

1. The main() function is added as an entry point to enable compilation as CMake project.
2. Added missing header.

[Update]
3. Added CMakeLists_HFInvMassFitter.txt and HFInvMassFitterLinkDef.h for fitter compilation as a standalone project.
4. Added Readme with instructions how to compile and run the fitter.

[github-actions]

O2 linter results: ❌ 1 errors, ⚠️ 0 warnings, 🔕 0 disabled

[vkucera]

Hi @lubynets , what exactly are you trying to do?
ROOT macros have the .C extension, their entry point is a function with the same name as the file and they are supposed to be executed in the ROOT interpreter.
You just added a main function but the rest remains unchanged.

[lubynets]

Hi @lubynets , what exactly are you trying to do? ROOT macros have the .C extension, their entry point is a function with the same name as the file and they are supposed to be executed in the ROOT interpreter. You just added a main function but the rest remains unchanged.

Hi @vkucera,
My purpose was to enable (in addition to ROOT interpreter) compiling the runMassFitter.C together with HFInvMassFitter.cxx/h as usual c++ code in CMake project or just from terminal using g++ command. This is how I use the fitter locally and I submitted the PR in order to (1) synchronize my copy of fitter with O2Physics and (2) share this version of compilation with others if somebody finds it useful.

[vkucera]

@lubynets OK. I think the use of the fitter should be documented somewhere. Do we not have an existing document for this?

[lubynets]

@lubynets OK. I think the use of the fitter should be documented somewhere. Do we not have an existing document for this?

Hi @vkucera,
As far as I know there is no such a document. I'll create one and add as a README file in the same folder (it can be further extended with instructions for other macros), ok?
I could also share the CMakeLists.txt for the fitter, but is it acceptable from the point of O2Physics structure? (since the fitter is not a part of common compilation).

[vkucera]

@lubynets OK. I think the use of the fitter should be documented somewhere. Do we not have an existing document for this?

Hi @vkucera, As far as I know there is no such a document. I'll create one and add as a README file in the same folder (it can be further extended with instructions for other macros), ok? I could also share the CMakeLists.txt for the fitter, but is it acceptable from the point of O2Physics structure? (since the fitter is not a part of common compilation).

That would be very useful indeed. If the CMakeLists.txt is short, you can include its content in the README file. Otherwise you can just commit the file itself and put a comment inside to make it clear that it is not supposed to be a part of O2Physics compilation. You can also add a suffix to the name (e.g. CMakeLists_runMassFitter.txt) to make it more obvious.

[vkucera]

Thanks @lubynets , looks good to me.
Just please fix the minor typo.

[lubynets]

Thanks @lubynets , looks good to me. Just please fix the minor typo.

Done