On 2007-09-07 18:30-0700 Alan W. Irwin wrote: > So why am I getting the above error at link time for plplotcanvas_demo? > > Further investigation shows an unexpected result. If I go ahead and link > plplotcanvas_demo with the additional option -Wl,--warn-unresolved-symbols > (which turns unresolved symbols into warnings rather than fatal errors), the > resulting plplotcanvas_demo passes the "ldd -r" test, i.e., the libXft and > libfreetype libraries are found at /home/software/pango_stack/install/lib/ > and there are no unresolved references! Furthermore, plplotcanvas_demo runs > without problems. > > So basically the linker says one thing (contrary to the nm -a evidence) and > ldd (which I believe invokes the run-time loader) says another about > unresolved references. > > Does anybody have a clue about any way (other than a linker bug) that > such an inconsistency might be possible? > > If you agree this is a really strange linking result that might be due to a > bug in my Debian sarge linker, I would appreciate some attempts at > confirmation on other platforms by building and installing the latest PLplot > from svn (on a fully loaded development platform that includes what is > needed to build the gnome canvas interface) and running make in the > installed examples/c directory. > > In fact, I am going to try the same test on my Ubuntu Dapper platform (where > I have a pango stack built from exactly the same source as on my Debian > sarge platform), but it is going to take a while (it is a 600MHz box) so I > will report later.
For the Ubuntu Dapper platform, plplotcanvas_demo links without issues, however, the evidence is inconclusive because for that platform libXft is not a dependence of any of the libraries that plplotcanvas_demo links to so it is not listed by ldd. So before reporting a result for your favorite platform, please apply ldd to plplotcanvas_demo to see whether libXft is involved. Also, just out of general curiosity about linking issues, I would be most interested if anybody can come up with a scenario on Linux platforms (other than a linker bug or ldd bug) where 'ldd -r' and the linker disagree on whether there are unresolved references. 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: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
