Problems building emacs-21.2 on IRIX with gcc-3.4.4

Problems building emacs-21.2 on IRIX with gcc-3.4.4

[Albert Chin]

I'm trying to build emacs-21.2 on IRIX 6.5.23m with gcc-3.4.4 (latest
3.4 release):
  $ gtar zxf /opt/src/editors/emacs-21.2/src/emacs-21.2.tar.gz
  $ gtar zxf /opt/src/editors/emacs-21.2/src/leim-21.2.tar.gz 
  $ cd emacs-21.2
  $ ./configure --with-gcc --with-x --with-x-toolkit=lucid
  $ gmake
  ...
  Wrote /opt/build/emacs-21.2/lib-src/fns-21.2.1.el
  Dumping under names emacs and emacs-21.2.1
  702632 pure bytes used
  ./emacs -q -batch -f list-load-path-shadows
  Fatal error (10).gmake[1]: *** [emacs] Bus error (core dumped)
  gmake[1]: Leaving directory `/opt/build/emacs-21.2/src'

gcc-3.3.2 works. Should I presume this to be a GCC bug?

-- 
albert chin (china@thewrittenword.com)

Re: Problems building emacs-21.2 on IRIX with gcc-3.4.4

[Richard Stallman]

    gcc-3.3.2 works. Should I presume this to be a GCC bug?

It could be, but you need to localize the problem to make sure.  You
could try compiling some files with GCC 3.3.2 and some with GCC 3.4.4,
and determine which file makes the difference.  Then you could try
splitting that file in various ways, to compile part of it with 3.3.2
and part with 3.4.4.  That way you can see which function fails.

At that point, you'll probably see that either the function contains
code that is not well defined in C, or that it has been miscompiled
by GCC 3.4.4.  Either way, we will know what to do.

Re: Problems building emacs-21.2 on IRIX with gcc-3.4.4

[Albert Chin]

On Fri, Jun 10, 2005 at 09:30:18AM -0400, Richard Stallman wrote:
>     gcc-3.3.2 works. Should I presume this to be a GCC bug?
> 
> It could be, but you need to localize the problem to make sure.  You
> could try compiling some files with GCC 3.3.2 and some with GCC 3.4.4,
> and determine which file makes the difference.  Then you could try
> splitting that file in various ways, to compile part of it with 3.3.2
> and part with 3.4.4.  That way you can see which function fails.
> 
> At that point, you'll probably see that either the function contains
> code that is not well defined in C, or that it has been miscompiled
> by GCC 3.4.4.  Either way, we will know what to do.

Thanks for the tip. We had one of the GCC developers look at the
problem (Eric Botcazou), and he found out that gcc-3.4.x is creating
some additional R/W ELF sections that the IRIX linker is not combining
(gcc-3.3.x created one R/W and one R/O ELF section). He plans to look
into this further. Hopefully we'll have a solution soon.

-- 
albert chin (china@thewrittenword.com)

Re: Problems building emacs-21.2 on IRIX with gcc-3.4.4

[Richard Stallman]

    Thanks for the tip. We had one of the GCC developers look at the
    problem (Eric Botcazou), and he found out that gcc-3.4.x is creating
    some additional R/W ELF sections that the IRIX linker is not combining
    (gcc-3.3.x created one R/W and one R/O ELF section). He plans to look
    into this further. Hopefully we'll have a solution soon.

It may need upgrading of unexelf.c in Emacs to handle more different
sections.

Re: Problems building emacs-21.2 on IRIX with gcc-3.4.4

[Albert Chin]

On Wed, Jun 15, 2005 at 10:45:46AM -0400, Richard Stallman wrote:
>     Thanks for the tip. We had one of the GCC developers look at the
>     problem (Eric Botcazou), and he found out that gcc-3.4.x is creating
>     some additional R/W ELF sections that the IRIX linker is not combining
>     (gcc-3.3.x created one R/W and one R/O ELF section). He plans to look
>     into this further. Hopefully we'll have a solution soon.
> 
> It may need upgrading of unexelf.c in Emacs to handle more different
> sections.

>From Eric, the difference in .data.* sections between gcc-3.3 and
gcc-3.4:
  (1) for 3.3: .data .data.rel.ro
  (2) for 3.4: .data .data.rel .data.rel.local

Any way to get unexelf.c to merge all the .data* sections?

-- 
albert chin (china@thewrittenword.com)

Re: Problems building emacs-21.2 on IRIX with gcc-3.4.4

[Richard Stallman]

    >From Eric, the difference in .data.* sections between gcc-3.3 and
    gcc-3.4:
      (1) for 3.3: .data .data.rel.ro
      (2) for 3.4: .data .data.rel .data.rel.local

    Any way to get unexelf.c to merge all the .data* sections?

Is it really right to merge them?  Shouldn't it preserve the identity
of each one?  (I am not sure, just guessing.)

In any case, we would like someone to make this change, but
IRIX is not terribly high priority.  We won't delay the release
for it, but we hope someone will do this.