can I declare a global variable in a shared library?

Question

Can I declare a global variable inside a library that is later compiled into a shared object ? Is it safe to reference it from other libraries or the main application code by de

Answer 1

Yes, libraries can contain global variables.

But depending on compiler/linker options, they might be not visible. E.g. it is common practice, that libraries are built with -fvisibility=hidden and that only certain symbols are exported (by linker map or explicit __attribute__((__visibility__)) tags).

Your "large" project has been probably built in such a way.

The high address might also indicate, that variable is some kind of other symbol (function) in another library.