Re: linking with extern DLLs under Cygwin

[Peter Rosin]

On Tue, Jan 22, 2008 at 10:40:43AM +0100, Denis Chancogne wrote:
> Hi,
> 
> I would like to make a patch to build php under Cygwin, but there is one
> problem with libtool.
> 
> When you pass to it the option -l<lib_name>, it search only libraries of
> type lib<lib_name>*
> to check that /lib/lib<lib_name>.dll.a exists (interface to dll). So it
> doesn't want to link
> with icu libraries because when you install icu libraries, in lib directory
> you have only
> dll file (cyg<lib_name>.dll) but no dll interface static library
> (lib<lib_name>.dll.a).
> 
> Today it is possible to link directly with dll file without static interface
> library to this dll,
> so I did a patch to search libraries of type "cyg<lib_name>.dll",
> "lib<lib_name>.dll" or
> "<lib_name>.dll" when you use option -l<lib_name> under cygwin. (I have
> added search
> of "<lib_name>.dll" because of ldflags returned by icu-config :
> 
> $ ./icu-config --ldflags
> -lpthread -lm -L/home/C82DHAN/tools/icu/3.8-org/lib -lcygicuin38
> -lcygicuuc38 -lcygicudt38 -lpthread -lm
> 
> )
> 
> I have already post this patch on address@hidden but there is no
> response ???
> ( http://lists.gnu.org/archive/html/libtool-patches/2007-12/msg00006.html )
> 
> Regards
> Denis
> PS: maybe icu installation should produce this kind of library and there
> would be no problem
> with libtool but not all the tools use libtool to produce their dll so when
> you use this previous tools
> there is only cyg<lib_name>.dll or lib<lib_name>.dll library file. (and no
> lib<lib_name>.dll.a)

This patch breaks it for users of $libname_spec, a variable you
have simply removed without notice. It may also break with
older tools that do not support linking directly with dlls
(but I don't know when that support was added and therefore I
don't know if it is a relevant argument).

It is not terribly hard to create those import libraries semi-
manually. dlltool can do most of the work. Is that not an
option for you?

Cheers,
Peter