Re: MacOSX module linking with static archive libtool problem

[Bob Friesenhahn]

Many/most operating systems require that anything linked into a shared
library be compiled as PIC.  The only way that libtool can be sure
that the code in a library is compiled as PIC is if it is also a
shared library.  Some system linkers will reject linking against
static libraries when building a shared library.  Modules are usually
shared libraries themselves so they observe the rules for building
shared libraries.

This is a libtool "feature" rather than a "bug".
There are system-dependent ways that libtool could work around this
problem for many systems, but it would be a lot of work to implement.

Bob

On Sun, 23 Feb 2003, Brad House wrote:

> Seems to be a bug in libtool 1.4.3 when linking a module if you want
> to use symbols out of an archive.  For example, inside of a package
> that uses autoconf/automake/libtool, a command executes:
>
> /bin/sh ../libtool --mode=link gcc -g -O2 -o module_ssl.la -rpath \
> /usr/local/lib -module -avoid-version module_ssl_la-module_ssl.lo \
> /usr/local/ssl/lib/libcrypto.a /usr/local/ssl/lib/libssl.a
>
>
> This message appears:
>
> *** Warning: Trying to link with static lib archive
> /usr/local/ssl/lib/libcrypto.a.
> *** I have the capability to make that library automatically link in when
> *** you link to this library.  But I can only do this if you have a
> *** shared version of the library, which you do not appear to have
> *** because the file extensions .a of this argument makes me believe
> *** that it is just a static archive that I should not used here.
>
> And does NOT link against libssl.a or libcrypto.a
>
> But when I:
> gcc -O2 -fno-common -flat_namespace -bundle -undefined suppress \
> -o module_ssl.so module_ssl.c /usr/local/ssl/lib/libcrypto.a \
> /usr/local/ssl/lib/libssl.a
>
> This module links perfectly, and is fully loadable within my
> main program.
>
> Any assistance here would be greatly appreciated.  I'd really rather
> not link against .dylib's as especially for SSL, I use 0.9.7a, and
> don't want to overwrite the dylibs Apple provides in /usr/lib,
> and the linker NEVER wants to link against the right dyamic version.
>
> -Brad
>
>
>
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======================================
Bob Friesenhahn
address@hidden
http://www.simplesystems.org/users/bfriesen