On 2015.04.06 at 16:45 -0400, Jason Merrill wrote: > On 04/06/2015 09:23 AM, Markus Trippelsdorf wrote: > > The issue is that clang uses the new libstdc++ ABI just fine. And before > > this commit one could switch compilers without any problems... > > Hmm, I suppose that when we switched to using inline namespaces for much > of the new ABI, switching compilers became more feasible; now tags are > only used for functions and variables, so you're less likely to run into > a problem, but it could still cause trouble if you use one of the tagged > functions in libstdc++ and get the one returning an old-ABI string. So > I would be nervous about using clang with a dual-ABI libstdc++. Does > clang use the new ABI by default with GCC 5 libstdc++?
Yes, (unless you explicitly use -D_GLIBCXX_USE_CXX11_ABI=0). I think most distros will use -D_GLIBCXX_USE_CXX11_ABI=0 for gcc-5, but on my Gentoo testbox I've already switched to the new ABI. And before your commit I could compile libraries with gcc and then use them with clang (and vice versa) without any issues. Now every library function with a std::string return type may cause linker errors. -- Markus
