bug#52711: undefined reference to '__muloti4'

bug#52711: undefined reference to '__muloti4'

[Alan Third]

I no longer seem to be able to build the master branch. I'm getting
this error:

  CCLD     temacs
fileio.c:6261: error: undefined reference to '__muloti4'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [Makefile:697: temacs] Error 1

I had a look but couldn't see where the problem comes from. I'm using
clang on Debian testing, if that matters.

I'm not sure when the problem started as I haven't built Emacs from
source on this machine in at least a couple of weeks.
-- 
Alan Third

bug#52711: undefined reference to '__muloti4'

[Eli Zaretskii]

> Date: Tue, 21 Dec 2021 19:30:42 +0000
> From: Alan Third <alan@idiocy.org>
> 
> I no longer seem to be able to build the master branch. I'm getting
> this error:
> 
>   CCLD     temacs
> fileio.c:6261: error: undefined reference to '__muloti4'
> clang: error: linker command failed with exit code 1 (use -v to see invocation)
> make[2]: *** [Makefile:697: temacs] Error 1
> 
> I had a look but couldn't see where the problem comes from. I'm using
> clang on Debian testing, if that matters.

Try using "nm -A fileio.o" to see what is that function and which code
calls it.

If nothing else helps, try bisecting.  (But my crystal ball says it
isn't Emacs that changed, it's something else on that system.)

bug#52711: undefined reference to '__muloti4'

[Alan Third]

On Tue, Dec 21, 2021 at 09:47:49PM +0200, Eli Zaretskii wrote:
> > Date: Tue, 21 Dec 2021 19:30:42 +0000
> > From: Alan Third <alan@idiocy.org>
> > 
> > I no longer seem to be able to build the master branch. I'm getting
> > this error:
> > 
> >   CCLD     temacs
> > fileio.c:6261: error: undefined reference to '__muloti4'
> > clang: error: linker command failed with exit code 1 (use -v to see invocation)
> > make[2]: *** [Makefile:697: temacs] Error 1
> > 
> > I had a look but couldn't see where the problem comes from. I'm using
> > clang on Debian testing, if that matters.
> 
> Try using "nm -A fileio.o" to see what is that function and which code
> calls it.
> 
> If nothing else helps, try bisecting.  (But my crystal ball says it
> isn't Emacs that changed, it's something else on that system.)

Looks like it's gnulib:

f05a93e8232e6f56458ac16d733b03e96a63e930 is the first bad commit
commit f05a93e8232e6f56458ac16d733b03e96a63e930
Author: Paul Eggert <eggert@cs.ucla.edu>
Date:   Sat Dec 18 16:12:38 2021 -0800
    Update from gnulib

I think the actual call is deep within some nested macros.
-- 
Alan Third

bug#52711: undefined reference to '__muloti4'

[Eli Zaretskii]

> Date: Tue, 21 Dec 2021 20:12:07 +0000
> From: Alan Third <alan@idiocy.org>
> Cc: bug-gnu-emacs@gnu.org, Paul Eggert <eggert@cs.ucla.edu>
> 
> On Tue, Dec 21, 2021 at 09:47:49PM +0200, Eli Zaretskii wrote:
> > > Date: Tue, 21 Dec 2021 19:30:42 +0000
> > > From: Alan Third <alan@idiocy.org>
> > > 
> > > I no longer seem to be able to build the master branch. I'm getting
> > > this error:
> > > 
> > >   CCLD     temacs
> > > fileio.c:6261: error: undefined reference to '__muloti4'
> > > clang: error: linker command failed with exit code 1 (use -v to see invocation)
> > > make[2]: *** [Makefile:697: temacs] Error 1
> > > 
> > > I had a look but couldn't see where the problem comes from. I'm using
> > > clang on Debian testing, if that matters.
> > 
> > Try using "nm -A fileio.o" to see what is that function and which code
> > calls it.
> > 
> > If nothing else helps, try bisecting.  (But my crystal ball says it
> > isn't Emacs that changed, it's something else on that system.)
> 
> Looks like it's gnulib:
> 
> f05a93e8232e6f56458ac16d733b03e96a63e930 is the first bad commit
> commit f05a93e8232e6f56458ac16d733b03e96a63e930
> Author: Paul Eggert <eggert@cs.ucla.edu>
> Date:   Sat Dec 18 16:12:38 2021 -0800
>     Update from gnulib
> 
> I think the actual call is deep within some nested macros.

If you do "nm -A libgnu.a", do you see this function in the library?
If so, from what file does it come?

bug#52711: undefined reference to '__muloti4'

[Alan Third]

On Tue, Dec 21, 2021 at 10:17:22PM +0200, Eli Zaretskii wrote:
> > Date: Tue, 21 Dec 2021 20:12:07 +0000
> > From: Alan Third <alan@idiocy.org>
> > Cc: bug-gnu-emacs@gnu.org, Paul Eggert <eggert@cs.ucla.edu>
> > 
> > On Tue, Dec 21, 2021 at 09:47:49PM +0200, Eli Zaretskii wrote:
> > > > Date: Tue, 21 Dec 2021 19:30:42 +0000
> > > > From: Alan Third <alan@idiocy.org>
> > > > 
> > > > I no longer seem to be able to build the master branch. I'm getting
> > > > this error:
> > > > 
> > > >   CCLD     temacs
> > > > fileio.c:6261: error: undefined reference to '__muloti4'
> > > > clang: error: linker command failed with exit code 1 (use -v to see invocation)
> > > > make[2]: *** [Makefile:697: temacs] Error 1
> > > > 
> > > > I had a look but couldn't see where the problem comes from. I'm using
> > > > clang on Debian testing, if that matters.
> > > 
> > > Try using "nm -A fileio.o" to see what is that function and which code
> > > calls it.
> > > 
> > > If nothing else helps, try bisecting.  (But my crystal ball says it
> > > isn't Emacs that changed, it's something else on that system.)
> > 
> > Looks like it's gnulib:
> > 
> > f05a93e8232e6f56458ac16d733b03e96a63e930 is the first bad commit
> > commit f05a93e8232e6f56458ac16d733b03e96a63e930
> > Author: Paul Eggert <eggert@cs.ucla.edu>
> > Date:   Sat Dec 18 16:12:38 2021 -0800
> >     Update from gnulib
> > 
> > I think the actual call is deep within some nested macros.
> 
> If you do "nm -A libgnu.a", do you see this function in the library?
> If so, from what file does it come?

No, it's not listed in the output...

OK, so some searching shows it's a clang bug that was only just fixed
last month, so won't be in whatever version of clang I've got access
to.

https://bugs.llvm.org/show_bug.cgi?id=16404

As described in that thread, adding this to LDFLAGS sorts it:

    --rtlib=compiler-rt --unwindlib=libgcc
-- 
Alan Third

bug#52711: undefined reference to '__muloti4'

[Paul Eggert]

On 12/21/21 12:12, Alan Third wrote:
> Looks like it's gnulib:

Indeed it is. In a recent Gnulib change I misspelled "__clang_major__" 
in an ifdef, which caused intprops.h to incorrectly assume that you were 
running Clang 14 (which isn't out yet) and therefore intprops.h did not 
work around Clang bug 16404, a bug that is present on your Clang 
11-based platform.

Sorry about that. I corrected the misspelling in Gnulib and propagated 
the latest Gnulib into Emacs, so it should work now.

bug#52711: undefined reference to '__muloti4'

[Alan Third]

On Tue, Dec 21, 2021 at 03:41:51PM -0800, Paul Eggert wrote:
> On 12/21/21 12:12, Alan Third wrote:
> > Looks like it's gnulib:
> 
> Indeed it is. In a recent Gnulib change I misspelled "__clang_major__" in an
> ifdef, which caused intprops.h to incorrectly assume that you were running
> Clang 14 (which isn't out yet) and therefore intprops.h did not work around
> Clang bug 16404, a bug that is present on your Clang 11-based platform.
> 
> Sorry about that. I corrected the misspelling in Gnulib and propagated the
> latest Gnulib into Emacs, so it should work now.

Thanks, Paul. That's it sorted now.
-- 
Alan Third