On 6 August 2014 10:06, Jakub Jelinek wrote: > On Wed, Aug 06, 2014 at 11:04:14AM +0200, Richard Biener wrote: >> > - libstdc++ ABI changes (it is a significant user visible change, >> > if you rebuild everything, no extra effort is needed, but otherwise >> > if you want some C++ code built with older compilers work together >> > with code built with newer compilers, it might require source code >> > changes (the abi_tag attribute additions where needed and warning >> > suggest to put those at), at least that is my current understanding >> > of the plans >> >> But that's only with -std=c++11? Which had no compatibility >> guarantees before? > > No, AFAIK it is also -std=c++98. At least my understanding was that > std::list and std::string are going to change ABI (and get new abi_tag) > in all C++ modes. Jonathan/Jason/Paolo, is that right?
Correct. We want C++03 code to continue to be able to interoperate with C++11 code. It's an ABI change for all modes (but not a SONAME change because the old and new definitions will both be present in the .so).