Add -fno-common where supported (WAF only)

[Rusty Russell]

On Thu, 12 May 2011 16:43:04 +0200, Andrew Bartlett <abartlet at samba.org> wrote:
> On Tue, 2011-05-10 at 05:22 +0200, Rusty Russell wrote:
> > 
> >     Add -fno-common where supported (WAF only)
> >     
> >     Normally under UNIX, uninitialized non-static global variables get
> >     placed in the "common" section, where they are merged at link
> > time.
> >     This means if two C files define "int debug", they will end up
> >     referring to the same variable.  Or if one does "float level" and
> > the
> >     other does "int level" you'll get an accidental union.
> >     
> >     Such bugs can be hard to track down; fortunately GCC offers
> >     -fno-common to disable this feature.  It didn't reveal any places
> >     which need fixing, however).
> >     
> >     Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
> 
> Rusty,
> 
> this breaks 'make SYMBOLCHECK=1', due to __progname in the setprogname
> implementation in Heimdal.
> 
> Can you look into this, and determine if the Heimdal roken use was
> invalid, or if it was deliberately referencing the __progname in the
> system libs?  It is fatally reported as a duplicate with my system libs,
> when I run that.

Thanks...

OK, if it wanted the one in the system libraries, it should be using
'extern const char *__progname;'.  The problem seems to be that you
have __progname, yet this is getting compiled:

source4/heimdal/lib/roken/getprogname.c:
        #ifndef HAVE___PROGNAME
        const char *__progname;
        #endif

We don't have a configuration test for HAVE___PROGNAME that I can tell,
yet it seems it should be set on your system?

Thanks,
Rusty.