Re: firefox-41.0 build fails on netbsd-7/i386

["John D. Baker" <jdbaker%mylinuxisp.com@localhost>]

On Sat, 26 Sep 2015, Greg Troxel wrote:

> Tobias Nygren <tnn%NetBSD.org@localhost> writes:
> 
> > On Fri, 25 Sep 2015 23:22:35 +0900 (JST)
> > Ryo ONODERA <ryo_on%yk.rim.or.jp@localhost> wrote:
> >
> >> >> The build still fails in the same way as before:
> >> >> 
> >> > 
> >> > Hmm... Strange.
> >> > I will try to build www/firefox under NetBSD/i386 7.0_RC3 again.
> >> 
> >> Hmm... I cannot reproduce your problem.
> >> Could you provide me your www/firefox/work/.work.log file?
> >
> > -march=i486 is not sufficient; it must have i586 for cmpxchg8b.
> > Here is a test program to verify this.
> > It will emit unresolved references to libatomic if you don't
> > use -march=i586 or higher.
> >
> > int main(void) {uint64_t x=0; return __sync_fetch_and_add(&x, 0);}
> 
> It seems that NetBSD has already given up on 486.   So restricting
> firefox to 586+ does not seem so terrible.    As someone said, it's
> unlikely to be bearable anyway.

I don't think it's NetBSD, per se.  I should note that Firefox v40.0.3
built on i386 just fine (even with the CPPFLAGS/CXXFLAGS botch).  The
"mozilla-common.mk" file did not change in that area between 40.0.3 and
the initial update to v41.0.

So it would seem that firefox started using code that ultimately depends
on the atomic operations not available with "-march=i486".  (I thought
there was a hack for that, but maybe that's just a kernel thing.)

Or perhaps there was a patch around it that has been misplaced?

> I have tried to build pkgsrc head firefox on netbsd-6 i386 and can
> confirm that it fails.

And the CPPFLAGS/CXXFLAGS correction (ieffective though it may be) came
just after the branch was tagged.  I've haxxor3d my "mozilla-common.mk"
to correct the variable name and use "-march=i586" instead.  Building
now (netbsd-6/i386 on a pentium-III).

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