Re: multiarch procedure

[Christopher Hulbert]

On Fri, May 9, 2008 at 9:20 AM, Bob Friesenhahn
<address@hidden> wrote:
> On Fri, 9 May 2008, Steve Edwards wrote:
>>
>> I've been using libtool quite happily for some time but have just started
>> looking at packaging libraries for x86_64 systems. I'm trying to find out
>> what the recommended method is for installation of x86_64 64bit libraries.
>
> Different systems use different approaches.
>
>> Is the only method to manually set --libdir at configure time (I have
>> libtool integrated with automake/autoconf)? I was a little
>
> The only way to be sure that things will work is to use --prefix and install
> into a different directory tree.  If you advise to use --libdir, then you
> still have the interface header files to worry about.  Interface header
> files often have different definitions for 32 and 64 bits.

I agree with this. I started out using the default redhat method of
lib64 and lib. After a while, and adding more platforms, compilers,
versions, etc. I found it useful to almost always use different
prefixes. That being said, I still have a mechanism in my configure to
use lib64, etc.

I use the code below to add a configure option to set a libdir suffix.
Thus, I can set it to create lib64, lib/x86_64, etc. Then, all my
other checks for packages try using $acl_libdirstem to link. If that
fails and it is not simply "lib", I try that for a mix of packages
some of which use lib64, some of which use separate prefixes. You
could also set a default, say based on the existance of "/usr/lib64"
for redhat systems.

AC_DEFUN([CHECK_LIBDIR_SUFFIX],
[
AC_ARG_WITH(libdir-suffix,
    AS_HELP_STRING([--with-libdir-suffix=suffix],[Suffix to apply to
library directories]),,with_libdir_suffix=)
])
acl_libdirstem="lib$with_libdir_suffix"
libdir="$libdir$with_libdir_suffix"


Hope that helps some.

>
>> I had a run through the libtool info at work and I'm sure I found a
>> tantalising reference to multiarch (with a comment along the lines of
>> "unless you know what this is you don't need it") but I certainly can't find
>> anything on my home system (libtool 2.2.4)
>
> Libtool 2.2.X includes support for automatically using 64-bit libraries on
> various popular systems (e.g. Solaris, Linux). Otherwise 64-bit builds would
> fail on systems which default to a 32 bit ABI.  It does not include
> multiarch/multilib support necessary to build 32 and 64 bit libraries and
> install into that footprint.
>
> Bob
> ======================================
> Bob Friesenhahn
> address@hidden, http://www.simplesystems.org/users/bfriesen/
> GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
>
>
>
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