How to generate a global function call graph for an entire C++ project

Question

The project contains multiple C++ files and contains multiple entry points. I want to generate a global function call graph for the entire project, which contains the functions in all the files in the project, i.e. only one function call graph is generated for the entire project.

I tried using doxygen, but it only generates function call graphs for each function, and it doesn't combine function call graphs for those functions. Is there any method? Thank you.