On 21 Jan 2013, at 16:54, Konstantin Belousov wrote: > On Mon, Jan 21, 2013 at 04:12:00PM +0000, David Chisnall wrote: >> On 21 Jan 2013, at 04:49, Konstantin Belousov wrote: >> >>> Yes, quite possible. AFAIR, the 'catch' code compares the exception classes >>> by the shared object ownership. It might get confused due to filter >>> providing >>> some symbols. >>> >>> But I did not investigated the cause for real. >> >> The issue appears to be that the libstdc++ exports a few functions[1] that >> libsupc++ exports, but with different symbol versions. Unfortunately, these >> are things that set handlers that are then called from libsupc++ / libcxxrt >> when, for example, an exception specification violation is encountered. >> >> I'm not sure what the solution is here. Is there some version-script-foo >> that we can do to say 'filter this symbol with this version as if it were >> this one with this version'? We ideally want to keep them with the current >> version in libcxxrt / libsupc++, but not introduce linker errors. >> >> David >> >> [1] std::set_new_handler(), std::set_terminate(), std::set_unexpected() > > Can you prepare the minimal isolated test case which demostrates the > behaviour ? A plan would be to ask somebody to run the test on the linux. > I think we must be bug-to-bug compatible with glibc in regard to the > filters quirks.
I'm not sure what you want the test case to demonstrate. I have a reduced form of the exception test case, but it only fails for us because of the symbol versioning issue. Moving the relevant symbols into the same version in our libsupc++ and libcxxrt as in libstdc++ fixes it (and is probably the right thing to do. On closer inspection both already expose new and delete in this symbol version namespace, so it's fine to add a few more). > Gnu filters work only on the whole object scope. Solaris linkers do > have per-symbol filtering, but Solaris does not implement per-symbol > versioning, on the other hand. If you want a simple test case for the filter behaviour, the recipe is: Symbol X in filter with version A Symbol X in filtee with version B Symbol Y in program uses symbol X Program sees version A, filtee sees version B. David
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