Front page | perl.perl5.porters |
Postings from October 2003
Michael Peppler wrote: > FYI DBD::Sybase and Sybase::CTlib fail at the "make test" stage on > Solaris (and possibly other platforms) with perl 5.8.1 and gcc 3.x. > > The problem is the default LDDLFLAGS configuration value that is used > with 5.8.1, which includes the following flags: > -z ignore -z lazyload -z combreloc > > For some reason these linker flags cause Sybase's -ltcl to NOT get > linked in to the .so file, with the result that DBD::Sybase and > Sybase::CTlib fail to load with relocation errors when trying to load > Sybase's libct.so (I've seen symbols "com_tds_maptoken" and > "dcl_result_drop" mentioned in the error message). Confirmed, with the Sun C compilers. The cause of the problem is the '-z ignore' option, which tells the linker to leave out any unreferenced files from the dependency list which is stored in the DBD::Sybase shared object. The Sybase libraries which use libcomn.so (for example) don't have the correct dependency lists, and are relying on the DBD::Sybase .so file to pull in all the dependencies that they might need. The DBD::Sybase .so doesn't refer itself to symbols from these libraries, and the '-z ignore' means they don't get recorded as dependencies, and don't therefore get loaded by the run-time linker. This is definitely a Sybase bug - *all* libraries should contain the *full* list of required dependencies, the Sybase ones only appear to have dependencies against libsocket - not even libc is included! If they don't have the correct dependency list you get this sort of issue, and all *sorts* of odd brokenness if you try using dlopen/dlclose on the libraries. $ dump -Lv /share/sybase,v11.1.1b/5.x/lib/*.so | grep NEEDED | sort -u [1] NEEDED libsocket.so.1 contrast that with (say) the system X11 library: dump -Lv /usr/lib/libX11.so | grep NEEDED [2] NEEDED libXext.so.0 [4] NEEDED libsocket.so.1 [6] NEEDED libnsl.so.1 [8] NEEDED libdl.so.1 [9] NEEDED libc.so.1 However, having said that this is Sybase brokenness, this still obviously needs a fix. The reason I added '-z ignore' in the first place was to make perl load a little faster - when building perl we use the same set of libraries on the link line for both the perl executable and libperl.so, but they have different dependencies, this is for 5.8.1 on Solaris: $ dump -Lv /usr/perl5/5.8.1/bin/perl | grep NEEDED [2] NEEDED libperl.so [4] NEEDED libdl.so.1 [5] NEEDED libc.so.1 $ dump -Lv /usr/perl5/5.8.1/lib/sun4-solaris-64int/CORE/libperl.so \ | grep NEEDED [2] NEEDED libsocket.so.1 [4] NEEDED libnsl.so.1 [6] NEEDED libm.so.2 [7] NEEDED libc.so.1 as compared to 5.6.1 $ dump -Lv /usr/perl5/5.6.1/bin/perl | grep NEEDED [1] NEEDED libperl.so.1 [2] NEEDED libsocket.so.1 [3] NEEDED libnsl.so.1 [4] NEEDED libdl.so.1 [5] NEEDED libm.so.2 [6] NEEDED libc.so.1 $ dump -Lv /usr/perl5/5.6.1/lib/sun4-solaris-64int/CORE/libperl.so | grep NEEDED [1] NEEDED libsocket.so.1 [2] NEEDED libnsl.so.1 [3] NEEDED libdl.so.1 [4] NEEDED libm.so.2 [5] NEEDED libc.so.1 By leaving out the required dependencies, and marking them as lazyload, we can speed up start-up slightly. I'm loathe to throw this change away, but I suspect we may have to. I'm wondering if it is possible to use one set of flags for building perl, and a different set for storing in Config.pm for building extensions? As a short-term workaround, you can edit Config.pm and remove '-z ignore' from ccdlflags and lddlflags -- Alan Burlison --Thread Next