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Re: libtool created import libs broken? was RE: DDD 3.3.8 (i686-pc-cygwin) gets `Segmentation fault
- From: Charles Wilson <cygwin at cwilson dot fastmail dot fm>
- To: cygwin-xfree at cygwin dot com
- Cc: bug-ddd at gnu dot org, cygwin at cygwin dot com
- Date: Thu, 04 Dec 2003 22:13:28 -0500
- Subject: Re: libtool created import libs broken? was RE: DDD 3.3.8 (i686-pc-cygwin) gets `Segmentation fault
- References: <DF08E278E10FC14F87CE7E802ABFD04B08247DD0@EXCHANGE01.air2web.com> <Pine.GSO.4.58.0312041737580.28297@eos>
Brian Ford wrote:
Could you look at the problem discovered in the thread below and give us a
There are a couple of problems.
1) OOB, DDD uses libtool-1.4.2 -- which has very minimal support for
cygwin. It works (barely) -- and it takes a whole chapter in the
autobook http://sources.redhat.com/autobook/ to explain the differences
from "normal" unix shared lib creation. The new 1.5+ procedure (with
binutils/gcc autoimport, autoexport, and .dll.a naming convention
support) is much more unix-like. Although ltmodules don't seem to work
very well, except in toy cases. :-(
2) Old libtool, when it finds a .la file (which specifies the DLL
name and the static lib name, AND the import lib name) doesn't appear to
handle the implib properly -- it thinks that it does not exist, and
attempts to recreate it from scratch using the export table from the
DLL. But it uses old, buggy, obsolete, unmaintained, code to do so.
Now, there are only four libraries in your link list that have .la
files: expat, fontconfig, freetype, and Xm. And whaddaya know -- those
are precisely the libs that cause problems in your link command.
QuickNDirty answer: hide those four .la files and re-run configure.
Long answer: update to the most recent autotools (relibtoolize).
bash-2.05b$ autoreconf --install --force
These are just warnings, so I think this part worked fine. I guess the
ddd people should clean these up?
Yes, they should -- when they are ready to move to autoconf-2.5x,
automake-1.7.x, and libtool-1.5+. But as you can see, there are
incompatibilities between autoconf-2.13 and -2.5x. Basically, you CAN
write a configure.in file that works with both -- but 2.13 was much more
forgiving than 2.5x, so most existing configure.in's need to be brought
up to 'spec' in order to work with 2.5x.
And the _easiest_ way to do THAT is to make changes to the configure.in
that are NOT backwards compatible with 2.13! So, it's possible to allow
both versions to work with your configure.in, but much harder than just
upgrading in a non-backwards-compatible way.
So most projects (like gcc/binutils until recently) have taken a
wait-and-see approach to autoconf-2.5x. Which leaves us poor cygwin
folks, who NEED libtool-1.5 for decent DLL support, out in the cold --
because libtool-1.5 requires automake-1.7.x which requires autoconf-2.5x...
(And, even though it is conceivable to use ac-2.5x with old-style
automake-1.4p6, the cygwin wrapper system doesn't let you do that. So,
if you re-autoconf with ac-2.5x, you'll also need to re-automake with
am-1..x -- which brings its own share of possible incompatibilities
in the Makefile.am's. And you'll want to add -no-undefined to the
libXXXXX_LDFLAGS setting for any libraries that DDD builds)
configure.ac:248: warning: AC_CANONICAL_HOST invoked multiple times
autoconf/specific.m4:363: AC_CYGWIN is expanded from...
configure.ac:248: the top level
autoheader: WARNING: Using auxiliary files such as `acconfig.h',
autoheader: WARNING: and `config.h.top', to define templates for
autoheader: WARNING: is deprecated and discouraged.
autoheader: WARNING: Using the third argument of `AC_DEFINE' and
autoheader: WARNING: `AC_DEFINE_UNQUOTED' allows to define a template
autoheader: WARNING: `acconfig.h':
autoheader: WARNING: AC_DEFINE([NEED_FUNC_MAIN], 1,
autoheader: [Define if a function `main' is needed.])
autoheader: WARNING: More sophisticated templates can also be produced, see
autoheader: WARNING: documentation.
Yep, you're gonna have to take care of this stuff by hand. I believe
that support for config.h.top etc will be going away in autoconf-2.60,
but that's **just** a guess. And anyway, 2.60 isn't expected for at
least several months (and 2.59 won't go 'poof' then, anyway)
Here is where we should have stopped, although I don't know how to do
that with autoreconf. The following are errors from subdirectories that
use older (circa 2.13) autoconf scripts. autoreconf does not support
mixed versions, I guess?
No, not at all. That's why Zack Weinberg (Nathaniel Nerode?) over on
the gcc list are updating gcc's (and friends') configure.in's by hand,
one directory at a time.
Bringing the autotool infrastructure up to snuff for a large project,
like DDD, is a significant challenge. And it's not a job that anyone
really wants to do -- so if you've the itch, the only person who will
scratch it is you. You'll need to do all this work yourself, and then
send your patches back to the DDD developers as a fait accompli, and
HOPE that they are ready to 'take the plunge', accept your patch, and
**force all of their developers to switch to using the new autotools**.
It's that last bit that causes trouble. And until they accept the
patches and take the plunge, you'll have to maintain your changes
out-of-baseline. And keep reapplying-and-reautotooling each time you
update to a new version of DDD.
One thing to keep in mind: when doing this, it helps to keep your
patches in separate 'piles'. I usually keep a 'pre-autotool' set, which
are the changes to configure.in, Makefile.am's, acinclude.m4's, etc.
Then, there's the 'post-autotool' set, which are the changes to those
files which are automagically updated by re-running
autoconf/automake/libtoolize (I usually include a 'bootstrap' script as
part of my 'pre-autotool' pile-o-patches [*]). Then, there's the 'code'
set (changes to actual code), and the 'cygwin-packinging' set (stuff
that goes in <srcdir>/CYGWIN-PATCHES/ like cyg-specific README, .hint,
postinstall script, etc -- that the upstream maintainers would NEVER be
[*] When actually releasing the cygwin package, there are two ways to do
this. The first way is to combine all four piles into one mondo patch,
and ship it as "the" patch for the package. (patchutils is your
friend). The downside is, often these patches are > 3M uncompressed,
thanks to the MASSIVE changes to the configure script, the
Makefile.in's, etc -- IOW, the 'post-autotool' pile-o-patches. The
second way is to only ship the pre-autotool, code, and cygwin-packaging
piles as the 'mondo' patch, and then adapt cygwin's
generic-packaging-script to run bootstrap as part of it's prep() phase.
This way, the patch is much smaller -- AND it's easier for you to
maintain. The downside is that (a) if anybody else wants to build your
version of the package, they must have the autotools installed, (b)
building is slow, because you have to run bootstrap each time [twice! --
again during mkpatch() for reasons I won't go into here -- if you're
interested, I can send one of my old packages where I had to do this,
and you can see how I did it and why. None of my current packages on
sourceware need to do this anymore...yay me.]
It's a royal pain...but there's no other choice, if (a) your-fav-pkg
won't compile properly on cygwin without modern autotool support, (b)
the upstream maintainers are unable/unwilling/properly-cautious to 'take
the plunge' and refuse to integrate your patches for a few release cycles.
configure.in:54: error: possibly undefined macro: AC_PROG_CC_GNU
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.
configure.in:65: error: possibly undefined macro: AC_PROG_CC_G
configure.in:198: error: do not use LIBOBJS directly, use AC_LIBOBJ (see
section `AC_LIBOBJ vs LIBOBJS'
configure.in:310: error: possibly undefined macro: AC_PROG_CC_WORKS
autoreconf: /usr/autotool/devel/bin/autoconf failed with exit status: 1
So, if this hasn't left your tree broken, I think it would test what I
wanted. You should now have libtool 1.5 for the main ddd tree. I think
it would fix this.
But if the subtrees are configured separately AND the subtrees use
libtool, then each subtree will create its own libtool during its own
sub-configure step -- and you're back to the mixed-version problem
New in 1.5: 2002-04-14; CVS version 1.4e, Libtool team:
* Support auto-import patch to binutils on cygwin for much improved dll
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