Post on the libtool mailing list as someone kindly suggested. Original thread at
https://sourceforge.net/forum/message.php?msg_id=3764300 :) ----Original Message---- From: Nobody [mailto:[EMAIL PROTECTED] On Behalf Of SourceForge.net Sent: Tuesday, June 06, 2006 5:53 AM To: [EMAIL PROTECTED] Subject: [mingw - C/C++] RE: Porting from linux/unix to windows - Libt [cut] > First, you should use dllexport on the symbols you want exported from > a library. > (And dllimport on those you are importing, except in your case this > isn't necessary as you're doing dynamic runtime linking.) I thought that was not necessary since I wanted to use libtool: I need some code that does not need to be changed but only cross-compiled. > Second, if you're using libtool you need to enable -no-undefined on > win32 if you want a shared library (that is why you only got a static > lib under Cygwin.) More details on this option here: > http://article.gmane.org/gmane.comp.gnu.mingw.user/18727 That was something I knew, but forgot! my fault! :) > Third, don't hardcode that the name of the shared library as ending in > .so in a makefile, as that is not portable at all. > It varies greatly -- .dll on windows, .dylib on Darwin, .a on some > systems, etc. Similarly you should use $(EXEEXT) instead of assuming > that executables have no extension. (If you used automake you > wouldn't have to worry about any of this, btw.) Unfortunately I cannot use automake at the moment; this is not my choice.. :( > Fourth, dlopen() does not exist on native Windows, so you should > expect link errors if you try to use it. Cygwin emulates dlopen(), so > if you're using Cygwin then you can use it just as you would on linux. > But not so on mingw which doesn't emulate anything. The native way of > doing things is > LoadLibrary() and GetProcAddress(). Now the whole point of ltdl is to > abstract away these kinds of differences, and so using it is the right > idea. However, the fact that you're still getting link errors about > dlopen would imply that you have an installation problem of ltdl. > Perhaps you're trying to use the Cygwin version of the library with > mingw -- that definitely won't work. You'll need a mingw-compiled > libltdl. This is something, again, I knew: but again, my fault: for some reason my libtool installation was broken. I've reinstalled everything. > Finally, please use the mailing list. These forums have a terrible > interface and the only reason that anyone ever responds to them is > because postings are one-way mirrored to the mailing list. (We have > discussed closing them permanently and I hope that happens ASAP.) Done; hope that now it's fine.... Ok, now I've fixed some stuff thanks to your advices... And finally have obtained, relying on lt_dlopen, lt_dlclose and so, something which does not need to be touched, and once compiled generates a .so on linux, a *cyg*.dll on cygwin, and a lib*.dll on mingw. Now: on mingw the generated binaries are an .exe and a .dll. I noticed that the executable does not only needs the .dll and the libltdl-3.dll (which was expected), but also the ".la" file. Did I make some mistake? In addition, is it due to have everithing under the ".lib\" folder? How can I control this? thanks.... for your patience... This is the new Makefile: ================================= LIBNAME=myprint TESTPROG=testlibprint EXEEXT=.exe LIBSTUB=lib$(LIBNAME) CLIB=$(LIBSTUB).C OLIB=$(LIBSTUB).o LOLIB=$(LIBSTUB).lo LALIB=$(LIBSTUB).la LIBEXT=.dll LIB=$(LIBSTUB)$(LIBEXT) NOUNDEFINED=-no-undefined GCC=g++ LIBTOOLPATH=#/usr/local/bin/ LIBTOOL=libtool LIBTOOLCMD=$(LIBTOOLPATH)$(LIBTOOL) LIBLTDLPATH=/usr/local/lib/ all: $(LIB) $(TESTPROG) $(OLIB): $(CLIB) $(LIBTOOLCMD) --mode=compile $(GCC) -g -O -c $(CLIB) $(LIB): $(OLIB) $(LIBTOOLCMD) --mode=link $(GCC) $(NOUNDEFINED) -module -g -O -o $(LALIB) $(LOLIB) -rpath /usr/local/lib -lm #ln -s .libs/$(LIB) . $(TESTPROG): $(TESTPROG).C $(LIBTOOLCMD) --mode=link $(GCC) $(NOUNDEFINED) -g -O -o $(TESTPROG)$(EXEEXT) $(TESTPROG).C -lm -rpath /usr/local/lib -L$(LIBLTDLPATH) -lltdl clean: rm -f $(OLIB) $(LOLIB) $(LALIB) $(LIB) $(TESTPROG)$(EXEEXT) rm -fr .libs ================================ Thanks in advance, kali _______________________________________________ http://lists.gnu.org/mailman/listinfo/libtool
