building DLLs with libtool and mingW - do I need the -o option to get a *.dll file?

[Ed Hartnett]

Howdy all!

I'm bringing an open source scientific data library into the libtool
universe.

One feature that lead to this this work was that ability (I
understand) of libtool/mingw/cygwin to produce windows DLLs.

In the past we have produced a DLL using a M$ compiler, but I would
like to maintain only one set of configuration files, so using libtool
seems like a real winner.

I have included the AC_LIBTOOL_WIN32_DLL macro in my configure.ac, and
the -no-undefined and -no-cygwin options in the linker flags.

When I do my make, everything seems to work, and I get a success
returned from make, but there is no .dll file in the
directory. (Although there is a libnetcdf.la file).

Did it work? Where is my dll?

Here's the output of the link:

/bin/bash ../libtool --mode=link --tag=CC gcc  -g -O2   -o
libnetcdf.la -rpath /home/Ed/lib -no-undefined -no-cygwin
-version-info 0:0:0 attr.lo ncx.lo putget.lo dim.lo error.lo
libvers.lo nc.lo string.lo v1hpg.lo var.lo posixio.lo v2i.lo  
gcc -shared  .libs/attr.o .libs/ncx.o .libs/putget.o .libs/dim.o
.libs/error.o .libs/libvers.o .libs/nc.o .libs/string.o .libs/v1hpg.o
.libs/var.o .libs/posixio.o .libs/v2i.o   -o .libs/cygnetcdf-0.dll
-Wl,--image-base=0x10000000 -Wl,--out-implib,.libs/libnetcdf.dll.a
Creating library file: .libs/libnetcdf.dll.a
ar cru .libs/libnetcdf.a  attr.o ncx.o putget.o dim.o error.o
libvers.o nc.o string.o v1hpg.o var.o posixio.o v2i.o
ranlib .libs/libnetcdf.a
creating libnetcdf.la

The libnetcdf.la file starts off like this:

# The name that we can dlopen(3).
dlname='cygnetcdf-0.dll'

# Names of this library.
library_names='libnetcdf.dll.a'

# The name of the static archive.
old_library='libnetcdf.a'

# Libraries that this one depends upon.
dependency_libs=''

Any comments about thie DLL process would be most helpful. I'm used to
getting one file: netcdf.dll - did I get something here that I can use
just by dropping it into a directory and then using a M$ IDE to
program with the DLL?

Thanks!

Ed


-- 
Ed Hartnett  -- address@hidden