[Bug c/98634] gcc 4.8.5 - 9.3.0 on target x86_64, when compile a exe and linking with a so, and exe's source file extern a var, the final exe has the var with the same name with the one in the so file

[zuogang at huawei dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98634

--- Comment #6 from zuogang <zuogang at huawei dot com> ---
(In reply to Jakub Jelinek from comment #5)
> No RHEL or Fedora compilers are -pie by default, I hate when such important
> details change silently under you.
> Instead of changing the GCC default in these distros the rpm macros ensure
> PIE by default when building rpm packages (unless one chooses to opt out).

I add -fPIE and no change, but I use -fPIC the var is not added into the elf
a.out file

why -fPIC turnoff the "copy relocation" ? but -fPIE doesn't