./configure script, which generates a Makefile with certain compiler and linker flags?-fPIC (as you're very much already aware).@bagder so then curl could, if it decided to, include a set of hardened default compiler flags.
setting certain compiler flags in the curl project would benefit all downstreams, not just the downstreams who themselves have hardened curl.
I suspect the curl developers know the curl codebase and which compiler flags would work better than some other random person with no experience in curl's source code.
@lattera in my experience, the ones who knows compiler options best are the compiler people and the ones building distros or otherwise build a lot for a specific platform.
We primarily focus on shipping source code that builds on 100 operating systems. We are not experts in the optimal options for fixed compiler on a particular specific plattforms.