Josselin Mouette schrieb: > Le vendredi 28 septembre 2007 à 11:43 +0200, Michael Biebl a écrit : >>> To avoid weird crashes caused by namespace conflicts, libtrackerclient >>> should be built with LDFLAGS += -Wl,-Bsymbolic. >> Hi Joss, >> >> the ld manpage was not particularly helpful regarding this topic. Could >> you please elobarate a bit more what -Bsymbolic does, why it is needed >> and if it has any downsides. > > Hi, > > this will avoid a kind of horrible bugs we have met with some GTK+ theme > engines. > > Let's say that libtrackerclient contains symbol foo - even if isn't part > of the public ABI. If there is a function named foo in a binary linked > to libtracker, calls to foo in other libtrackerclient functions will > instead use the binary's foo symbol. > > If the client is directly linked to the library, this behavior is > desirable, so that foo can be overridden. If there is something wrong > with this override, it will fail in all cases and will be quickly > spotted. > > However, as the library is dlopen()ed, it has the potential to come in > the global symbol table of virtually any GTK+ application, but not all > the time. If for some reason, another binary has a symbol named foo > which has nothing to do with libtrackerclient's foo, it will be used > instead and will lead to bugs that are very hard to understand and > reproduce as the stack looks corrupt and the library is not always > dlopen()ed. > > This is why it is a good idea for *all* Pango and GTK+ plugins to be > linked with -Bsymbolic. This option guarantees that a function in > libtrackerclient that calls "foo" will obtain the function "foo" defined > in libtrackerclient, nothing else. >
There are also clients which directly link against libtrackerclient (like nautilus or tracker-search-tool). Would this have a negative effect for them? Cheers, Michael -- Why is it that all of the instruments seeking intelligent life in the universe are pointed away from Earth?
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