On 2008-09-12 09:07+0200 Arjen Markus wrote:
> - Are symbols imported from the C library to accommodate the Fortran or other
> bindings automatically visible via these other libraries? I mean: is the
> visibility
> transitive?
Fortunately, the above complicated case does not apply to our Fortran and
C++ libraries. For example, if you look at the CMakeLists.txt files for the
Fortran 95 examples, you will see this line:
target_link_libraries(x${STRING_INDEX}f95 plplotf95${LIB_TAG})
That means our various Fortran 95 examples only have undefined symbols that
are resolved by libplplotf95d, and for example, there are no C symbols from
libplplotf95cd, libplplotd, libcsirocsa, or libcsironn directly required by
our Fortran examples (as you would expect).
Moving one up in the hierarchy, you will find
target_link_libraries(plplotf95${LIB_TAG} plplotf95c${LIB_TAG})
That means libplplotf95d only has undefined symbols that are resolved by
libplplotf95cd, and there are no C symbols from libplplotd (or libcsirocsa,
or libcsironn) directly required by libplplotf95d.
Moving one more up in the hierarchy, you will find
target_link_libraries(plplotf95c${LIB_TAG} plplot${LIB_TAG})
That means libplplotf95cd only has undefined symbols that are resolved by
libplplotd, and there are no C symbols from either libcsirocsa or libcsironn
directly required by libplplotf95cd.
Finally, moving one more up in the hierarchy, you will find
target_link_libraries(
plplot${LIB_TAG}
${libplplot${LIB_TAG}_LINK_LIBRARIES}
)
where the ${libplplot${LIB_TAG}_LINK_LIBRARIES CMake list variable contains
different external libraries and link flags depending on CMake logic. For
the case where WITH_CSA is true, then the list includes libcsirocsa. That
means for that case libplplotd has undefined symbols that are resolved by
libcsirocsa. And similarly for HAVE_QHULL and libcsironn.
I hope that detailed example clarifies your thoughts on what symbols should
be visible for what libraries in the Fortran95 (and equivalent Fortran 77)
chain of libraries. To summarize these particular example/library chains,
an example or library at one level in the hierarchy only requires a library
from one higher level in the hierarchy. If you look at
examples/c++/CMakeLists.txt and bindings/c++/CMakeLists.txt you will see the
C++ examples and libplplotcxxd also share this same useful property.
Here is what I suggest you and Werner do to follow up on this. You have
already indicated earlier in this thread you were not quite sure about what
circumstances required use of __declspec(dllimport). So I suggest you look
very carefully at all traditional and non-traditional documentation
accessible to you to see under exactly what circumstances
__declspec(dllimport) should be used for undefined symbols in a library.
Note especially that a very good non-traditional source of documentation
for Windows development is the CMake mailing list. Note also that questions
about __declspec(dllimport) have been asked and answered there before so you
may want to do a google search of the CMML archives before you ask your
questions on that mailing list.
Once you know the exact circumstances where it is necessary to specify
__declspec(dllimport), then you will be in a good position to figure out how
to support that requirement using a combination of CMake logic and #defines
in our various *dll.h files.
Good luck in getting this all sorted out so that the Fortran cases and the
C++ case build and give good ctest results for bare Windows and MinGW.
Alan
__________________________
Alan W. Irwin
Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).
Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of
Linux Links project (loll.sf.net); and the Linux Brochure Project
(lbproject.sf.net).
__________________________
Linux-powered Science
__________________________
-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Plplot-devel mailing list
Plplot-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/plplot-devel
