[gnutls-devel] Guile bindings for GnuTLS don't build as shared library on MinGW

[Ludovic Courtès]

Eli Zaretskii <eliz at gnu.org> skribis:

>> From: ludo at gnu.org (Ludovic Courtès)
>> Cc: gnutls-devel at lists.gnutls.org
>> Date: Tue, 09 Dec 2014 21:20:44 +0100
>> 
>> Could you post config.log, to check what Libtool thinks of shared
>> library support?
>
> Attached below.  Excerpts which looked relevant to me:

OK, everything seems normal here.

>   $ cd guile/
>   $ make -W ../config.h V=1
>   Making all in modules
>   make[1]: Entering directory `/d/usr/eli/utils/gnutls-3.3.10.with-guile/guile/modules'
>   make[1]: Nothing to be done for `all'.
>   make[1]: Leaving directory `/d/usr/eli/utils/gnutls-3.3.10.with-guile/guile/modules'
>   Making all in src
>   make[1]: Entering directory `/d/usr/eli/utils/gnutls-3.3.10.with-guile/guile/src'
>   make  all-am
>   make[2]: Entering directory `/d/usr/eli/utils/gnutls-3.3.10.with-guile/guile/src'
>   /bin/sh ../../libtool  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. -I../..  -I../../lib/includes  -I../../lib/includes     -I../../extra/includes  -I../..  -I. -Id:/usr/include -Wno-strict-prototypes  -I../../gl -I../../gl -Id:/usr/include/guile/2.0 -Id:/usr/include   -O2 -g3 -MT guile_gnutls_v_2_la-utils.lo -MD -MP -MF .deps/guile_gnutls_v_2_la-utils.Tpo -c -o guile_gnutls_v_2_la-utils.lo `test -f 'utils.c' || echo './'`utils.c
>   libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I../.. -I../../lib/includes -I../../lib/includes -I../../extra/includes -I../.. -I. -Id:/usr/include -Wno-strict-prototypes -I../../gl -I../../gl -Id:/usr/include/guile/2.0 -Id:/usr/include -O2 -g3 -MT guile_gnutls_v_2_la-utils.lo -MD -MP -MF .deps/guile_gnutls_v_2_la-utils.Tpo -c utils.c  -DDLL_EXPORT -DPIC -o .libs/guile_gnutls_v_2_la-utils.o

So it builds both the static and the PIC version.

>   mv -f .deps/guile_gnutls_v_2_la-utils.Tpo .deps/guile_gnutls_v_2_la-utils.Plo
>   /bin/sh ../../libtool  --tag=CC    --mode=link gcc  -Wno-strict-prototypes  -I../../gl -I../../gl -Id:/usr/include/guile/2.0 -Id:/usr/include   -O2 -g3  -module -g3 -o guile-gnutls-v-2.la -rpath d:/usr/lib/guile/2.0 guile_gnutls_v_2_la-core.lo  guile_gnutls_v_2_la-errors.lo guile_gnutls_v_2_la-utils.lo ../../lib/libgnutls.la ../../gl/libgnu.la  -Ld:/usr/lib -lguile-2.0 -lgc   -lintl  -lregex
>   libtool: link: warning: undefined symbols not allowed in i686-pc-mingw32 shared libraries
>   libtool: link: rm -fr  .libs/guile-gnutls-v-2.a .libs/guile-gnutls-v-2.la .libs/guile-gnutls-v-2.lai

Here it chooses to build the static library.

The command line lacks -no-undefined compared to the other one you
posted, which may be the explanation.  Could you try:

  make clean -C guile
  make -C guile LDFLAGS=-no-undefined

?

>> The ‘-module’ option is used to create “a library that can be dlopened”
>> (info "(libtool) Link mode"), and is a prerequisite when leaving out the
>> ‘lib’ prefix.
>
> How is this “library that can be dlopened” different from a "normal"
> shared library?

I think some OSes view shared libraries as something different from
dlopenable modules (early OS X had .dylib for the former and .so for the
latter, IIRC.)  There’s also the “dlpreopening” concept for OSes lacking
dlopen–which may be irrelevant nowadays (info "(libtool) Dlpreopening").

Thanks,
Ludo’.