[Gcl-devel] Re: Call for help with MACOSX Re: [Axiom-developer] [MACOSX] What is unexec and why does it fail ?

[Camm Maguire]

Aurelien!!!  It is *so* nice to hear from you!  I hope all is well
with you and yours.


Beyond the axiom issue discussed below, some acl2 users at the
University of Texas are running into difficulties with the mac code
when making very large images.  Would you have a chance to try to
build ACL2 with maxpages doubled, quadrupled, and even multiplied by 8
if you OS allows?  Please let me know if you have some time to
investigate this.  I can send you more information if so.


Aurelien Chanudet <address@hidden> writes:

> Hi Camm and all,
> 
> Sorry for seeming unreachable ! Having no access to
> the Internet at home for the time being, I find it
> quite difficult to contribute efficiently to gcl. All
> I was able to do recently was spend one full week
> feedling with gdb, tracing the route of segfaults from
> the kernel all the way to the debugger, trying to sort
> out why gdb doesn't handle segfault on MacOSX the way
> it does on Linux.

What dedication!  Is this a known issue on the Mac?  Any help from the
gdb developers?


> 
> Some remarks concerning Pierre's output :
> 
> - There's a README.macosx file enrolled in the CVS
> repository
> (http://savannah.gnu.org/cgi-bin/viewcvs/gcl/gcl/README.macosx).
> Camm, could you please change the CVS option for this
> file so as to make it appear in CVS head ? If you want

I'm not sure what you mean here.  Its in the CVS head tree (aka 2.7.0)
to my understanding.  Should I post it to the website on the errata
page?  

> to learn more about unexec, try looking for Andrew
> Choi's work for Emacs.
> 

Thanks for the tip -- will dig in as time allows.  I don't know if you
saw my previous note on this, but I feel that if we can extend unexec
in two ways, it would be greatly advantageous to GCL.  

1) Add reloc records for any symbols relocated to a dlopened library
   in a given session, together with whatever section is also needed
   to indicate that the image is (now permanently) dynamically linked
   against the lib.

2) Merge gprof section info from any loaded .o files into the final
   saved image so that profiling will work without having to generate
   a fresh image with ld.

Already discussed with the emacs people, who don't seem to have the
time for the work themselves.

Beyond this, of course, is extending native loading to alpha, ia64,
mips, and hppa.  And, as long as we're making this list, it would be
great if we could eliminate the 1.5Mb image bloat incurred by using
bfd instead of the older reloc code -- this doubtlessly comes from
storing the hash table of all the symbols permanently in the image,
which should be fast, but perhaps not significantly so.

> - The error you're running into ("not enough room for
> load commands for new __DATA segments") is due to your
> configure options. As a general rule, I highly
> recommend using --enable-locbfd and --disable-dlopen.
> I don't even know if the dlopen option is available on
> MacOSX.
> 

Tim, Pierre -- are you not building this way already?


Take care,


> --- Camm Maguire <address@hidden> wrote:
> > Greetings!
> > 
> > This is an official call for help from someone
> > familiar with the Mac
> > and in particular with its mach-o binary file
> > format.  We have an in
> > general very high quality custom port of the gcl
> > object relocation and
> > image writing code to this platform graciously
> > contributed by
> > Aurelien, but it appears that he is no longer
> > reachable, and there are
> > large image issues with his code in acl2 as well.  I
> > have access to a
> > Mac account and can ascend the learning curve here
> > if necessary -- it
> > would simply be much more efficient if someone with
> > the requisite
> > knowledge already in hand would step forward.
> > 
> > Take care,
> > 
> > Pierre Doucy <address@hidden> writes:
> > 
> > > Hi all,
> > > 
> > > Attempting to compile Axiom on my Mac, I get the
> > following error :
> > > 
> > > [...]
> > > 44 invoking make in
> > >
> >
> /Users/pdoucy/Documents/Travail/Axiom/axiom--MACOSX--1--patch-1/src/boot
> > > with parms:
> > > SYS= MACOSX
> > > LSP=
> >
> /Users/pdoucy/Documents/Travail/Axiom/axiom--MACOSX--1--patch-1/lsp
> > > PART= cprogs
> > > SPAD=
> >
> /Users/pdoucy/Documents/Travail/Axiom/axiom--MACOSX--1--patch-1/mnt/MACOSX
> > > SRC=
> >
> /Users/pdoucy/Documents/Travail/Axiom/axiom--MACOSX--1--patch-1/src
> > > INT=
> >
> /Users/pdoucy/Documents/Travail/Axiom/axiom--MACOSX--1--patch-1/int
> > > OBJ=
> >
> /Users/pdoucy/Documents/Travail/Axiom/axiom--MACOSX--1--patch-1/obj
> > > MNT=
> >
> /Users/pdoucy/Documents/Travail/Axiom/axiom--MACOSX--1--patch-1/mnt
> > > unexec: not enough room for load commands for new
> > __DATA segments
> > > make[3]: ***
> >
> [/Users/pdoucy/Documents/Travail/Axiom/axiom--MACOSX--1--patch-1/obj/MACOSX/bin/bootsys]
> > > Error 1
> > > make[2]: *** [bootdir] Error 2
> > > make[1]: *** [srcdir] Error 2
> > > make: *** [all] Error 2
> > > 
> > > As it looked like a memory problem, I changed my
> > gcl configure options to:
> > > 
> > > ./configure --enable-vssize=65536*4
> > --enable-maxpage=256*1024
> > > --enable-machine=powerpc-macosx --enable-dlopen
> > --disable-locbfd
> > > 
> > > but still get the same error.
> > > After some googling, I haven't been able to find
> > any clear doc about
> > > what unexec is, and what it does.
> > > Can anyone explain me what it is supposed to do,
> > and why it might fail
> > > in such a manner ?
> > > 
> > > Thank you in advance.
> > > 
> > > Pierre DOUCY
> > > -- 
> > > Cats are intended to teach us that not everything
> > in nature has a function.
> > > 
> > > 
> > > _______________________________________________
> > > Axiom-developer mailing list
> > > address@hidden
> > >
> >
> http://lists.nongnu.org/mailman/listinfo/axiom-developer
> > > 
> > > 
> > > 
> > 
> > -- 
> > Camm Maguire                                                address@hidden
> >
> ==========================================================================
> > "The earth is but one country, and mankind its
> > citizens."  --  Baha'u'llah
> 
> 
> 
>       
>       
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-- 
Camm Maguire                                            address@hidden
==========================================================================
"The earth is but one country, and mankind its citizens."  --  Baha'u'llah