API implementation

I work for avionics domain. In order to use open GL API’s which we got from Mesa3D, we need to test the API’s itself for certification purpose. So in order to test them we have to trace each API. We came to know that glfunc() will be implemented by a _mesa_func(). I want to know how this is mapped???

We came to know that glfunc() will be implemented by a _mesa_func().

Says who? What happens within the boundary of an OpenGL call is up to the OpenGL implementation. You would only get some _mesa_func call if your implementation used Mesa. What happens internally is… internal, and generally not available to be seen.

For your needs, I would suggest investigating OpenGL SC. It’s designed to aid in handling certification issues and so forth.