Because sometimes you need to know which version of the code you are working with.

1. Edit your_config_file.xml,
2. Run: ./VersionHeaderGenerator.py your_config_file.xml,
3. The generated file is placed in a proper place (look to the config file to check the place).

1. NAME,
2. GIT_REVISION_HASH,
3. GIT_SHORT_REVISION_HASH,
4. GIT_BRANCH,
5. GENERATION_TIME,
6. GENERATION_DATE,
7. COMPILATION_TIME,
8. COMPILATION_DATE,
9. GUARD_DEF.

Insert proper entry in your your_config_file.xml. E.g: <your_important_variable>(0xDEADBEEF)</your_important_variable>

Run it: cd example ; make

*) Of course, they aren't variables from the point of view C/C++ language and its compilation. They are variables from point of view of project management.