Re: Obsoleting LT_SCOPE

[Charles Wilson]

On 10/25/2011 11:51 AM, Gary V. Vaughan wrote:
> I have to bow to your superior knowledge of Windows, which I haven't used
> for development since Windows NT 4, but it feels weird that Libltdl really
> does twist itself into a pretzel for Windows... and yet all the other GNU
> projects I've looked at do no such thing (possibly because I haven't yet
> found another one that can be compiled with MSVC).

Well, a couple of points: #1, libltdl is not normal: unlike most 
libraries, we provide explicit support for (a) linking externally, (b) 
incorporating as a subproject and linking locally (separate 
./configure), and (c) incorporating as a submodule(?) and linking 
locally (combined ./configure).  Very few other libraries support any 
such thing OOB.

#2, I can think of one other GNU projects that support similar 
sub-inclusion: libintl.  And /that/ library, and its cousin libiconv, 
also twist themselves into giant pretzels for Windows -- even moreso 
than libltdl.  Bruno invented a whole new method of linking! 
http://www.haible.de/bruno/woe32dll.html

BTW: one possible solution to this whole conundrum is to adopt Bruno's 
method [*], which works for both MSVC and gcc.  The idea is to *always* 
declare "exported" symbols as declspec(dllimport), even when linking 
against the static library.  The trick is, some additional build steps 
when building the library itself, to add the requisite "import" thunks 
to the static lib.  See the URL above for more info.

FWIW, Bruno has long said that this method would "work better" with 
"just a few additional lines of code in libtool".  However, as he's 
never actually posted just WHAT those additional lines of code would BE, 
I've been at a loss to move forward.  That's been the status now for 
several years (not really high on my priority list).

[*] without the -Wl,--disable-auto-import

--
Chuck