pkg-fallout: duplicate symbols?

[Bob Eager]

On Wed, 2 Sep 2020 14:44:36 -0000 (UTC)
Christian Weisgerber <naddy at mips.inka.de> wrote:

> On 2020-08-22, Dimitry Andric <dim at FreeBSD.org> wrote:
> 
> > It can be worked around by adding -fcommon to the compilation
> > flags, but in most cases it should not be too difficult to get rid
> > of the multiply defined symbols.  
> 
> Right.
> In C, a global is _defined_ in one object file and _declared_ when
> it is referenced from elsewhere.  See Kernighan & Ritchie.  Commons
> are a linker artifact that was never part of the C language, as far
> as I can tell.
> 
> Most instances turned up by -fno-common are accidental double
> definitions of the same global, so you only need to turn the extra
> definitions into declarations.  However, in some cases they were
> actually intended as separate variables and have been merged by
> accident.  In those cases, they should be renamed or made local
> with "static".

In some cases, it is deliberate. An initialised, but declared, global
is used as a 'weak' global that can be overridden by checking its value.

I maintain one port that does this!