[Cppqed-support] git commits in version information

[Raimar S. <rai...@ui...>]

Dear András,

I have tackled the next point on the issues list: version information with git commit sha1 values. This is non-trivial if you want to have the git commits of _all_ repositories which make up a particular script. This can of course only be achieved in the scripts project itself, as only there all the other repositories are known (core, elements, custom elements, custom scripts).

Please have a look at C++QED_core (branch version) and CustomScriptsExample (branch version). These are branched from master, so you will need C++QED_elements and CustomElementsExample from master.

When you run 2ParticlesRingCavitySine --version, you will see something like:

# C++QEDcore Version 2.9.1, core git commit: b70df0f1ce07ba6c4cf4130fc6c7c5b29e82a95b
# elements git commit: f42c89e651211f572c75f363a368f2e67f0b6883
# elements_custom_example git commit: c2b9647117e47fd1f4d9e6714fe6079121756e1c
# scripts_custom_example git commit: 5417c29938df3dce9fcdb9b53f4a6ec0a859ee1b

# Andras Vukics, vu...@us...

# Compiled with
# Boost library collection : Version 1.54
# Gnu Scientific Library   : Version 1.15
# Blitz++ numerical library: Config date: Fri Aug 30 13:01:08 CEST 2013

When you run the simulation, you will notice that the exact same version information is included in the header of the data. This is made possible by adding the following line to the script:

updateVersionstring(cppqed_component_versions());

Without this call (all the original scripts), the version string will only contain the core git commit. To take advantage of the full version information, only "Version.h", "component_versions.h" and the call to updateVersionstring has to be included in a script.

When you add a new commit in one of the repositories, cmake will automatically be run to regenerate the correct version information. Only very little code containing the version string needs to be recompiled, the rest is done by relinking.

If you agree, I will merge this into master and Development.

Best regards
Raimar


Implementation details:

All libraries now have the function cppqed_*_version() returning the git commit as string, where * is core, elements, elements_custom_example etc. If the project name is "core" then also the numerical version of C++QED as defined in the CMakeLists.txt is included. The definition and declaration is auto-generated by cmake.

Additionally, script executables are linked with the autogenerated function cppqed_component_versions(), where all the cppqed_*_version() strings of the sub-components are combined. 

In the core library there is now a global variable cppqed_versionstring which is initialized with the core version information. The function updateVersionstring can be used in scripts to update the global variable with the more accurate version information given by cppqed_component_versions().  The global variable is then consulted via versionHelper() if --version is present on the command line and for the data header.

You can have a look at all the auto-generated .cc and .h files, they are in the top level build directories of the projects.