I'm trying to see if I can compile the plasma physics code xoopic (the
non-commericial verion) on my personal laptop using cygwin-x. They have their
own library of graphing routines called xgrafix which uses xwindows. In their
pub directory they also have tar files that are just xgrafics distributions
with test code. I do scientific programming on unix systems for a living, so I
figured that if I could get xgrafix to compile and execute its test programs on
cygwin-x, then, I should be able get the full xoopic distribution to compile,
perhaps with a little extra work.
I ran the default unix configuration file just to see what it needs. The only
show stoppers were that it was looking for libX11.a, libXpm.a, libtcl.8.4.a and
libtk.8.4.a. The last two it pieced together from info in their respective
confxxx.sh scripts. I quickly located the corresponding import libs for the
standard cygwin-x system (I'm fine with the standard dynamic linking, this is
for my personal use recompiling a static distribution is just too much like
work for my purposes).
I believe the correct import libs for me would be: libX11.dll.a, libXpm.dll.a,
libtcl84.dll.a and libtk84.dll.a. I seem to recall a couple of other libraries
that started with libtcl and libtk so correct me if I'm wrong. When I just
stuck in the absolute path name variables to those import libs in the configure
file, which overrides the tests, it found the import libs and made
Makefiles that actually compiled, including the test.c program. Note that I
checked the Makefiles and they had the right "-l" switches for everything.
(The fortran test didn't compile but I can beat that into submission by myself,
later.) But the c test hangs when it runs, probably because the
resulting Makefile didn't link think the libraries correctly. I tried a couple
of variations editing the Makefiles, even using the actuall DLL.s as the
libraries but get the same result.
I've gotten spoiled by having a support person for scripts and makefiles and
the like for the last several years and we don't generally use gnu compilers
anyway so I'm not sure of the best way to proceed at this point. So here are my
questions:
Question 1.) Currently it is building static archive - xgrafix.a. Since I'm
building a graphics library that links to the X11, Xpm, Tcl and Tk DLLs, do I
need to compile it (xgraphics) as a DLL? It might work either way but I'm fine
with whatever works best. To wit, I found the following useful entry in the
cygwin user's guide under "Building and Using DLLs.
-------------------------------------------------------------------------------------------------------------------------------------------------------
However, if you are building a dll as an export library, you will probably want
to use the complete syntax:
gcc -shared -o cyg${module}.dll \
-Wl,--out-implib=lib${module}.dll.a \
-Wl,--export-all-symbols \
-Wl,--enable-auto-import \
-Wl,--whole-archive ${old_libs} \
-Wl,--no-whole-archive ${dependency_libs}
The name of your library is ${module}, prefixed with cyg for the DLL and lib
for the import library. Cygwin DLLs use the cyg prefix to differentiate them
from native-Windows MinGW DLLs, see the MinGW website for more details.
${old_libs} are all your object files, bundled together in static libs or
single object files and the ${dependency_libs} are import libs you need to link
against, e.g '-lpng -lz -L/usr/local/special -lmyspeciallib'.
---------------------------------------------------------------------------------------------------------------------------------------------------------
If I make it xgrafix.dll, I'll probably use this as a template so I get the
import lib without having to run dlltool. But I find this a useful summary
whether I make it a DLL or not.
Question 2..) Whether I build xgrafix as a DLL or not, do I just need the
import libs to compile (aside from the real library paths)? That is, would I
need to specify the actuall DLLs as well somewhere, like in "old_libs" above or
in an absolute path name, to link the xwindows, tcl and tk DLLs I need? Or do I
even need the import libs - would just the corresponding "-l" switches suffice?
Question 3.) Since I'm considering using the above command as a template, I'm
thinking I can just use the object files I can already make in the top-level
(xgraphics routines) directory to make a DLL with the right switches. Is that
right? What I'm assuming is that those object files don't know whether they're
supposed to be linked to a DLL or staic lib, so I can just link them from the
command line to make a DLL. Please correct me if I'm wrong.
Question 4.) This is sort of a repeat of question 2, probably. When I make the
test.c exectuable, do I need to specify anything (xgraphix specific) other than
xgrafix.dll.a (along with its path)?
Sorry if these seem really basic to cygwin-x programmers out there but the
documentation is a bit spotty on these linking issues. I'd appreciate a little
brief explaination of these issues.
Thank you,
-Mike Rogers
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