libstdc++ solution?

[AndrewBelt]

In the README, you mention

If you want C++, you'll need to build libstdc++ with this enabled. That can be a little involved, but I'm working on a solution, to be available "soon".

I'm interested in what your ideas are for libstdc++. Is it as simple as generating a header of symvers for libstdc++ versions?

[jwakely]

Is it as simple as generating a header of symvers for libstdc++ versions?

No, that won't work. In libstdc++ there is only one version of a given symbol, so it's not possible to force it to bind to an older version.

The typical problems with libstdc++ library versions are due to entirely new symbols added to libstdc++.so.6 not with new versions of symbols. And if you compile using a new GCC and its new libstdc++, such that you depend on new symbols in that release of libstdc++, then no amount of messing with symbol versions is going to make the new symbols present in an older libstdc++.so.6. They just aren't present.

There are two correct solutions: either build with an old GCC so you only depend on an old libstdc++.so, or use something like Red Hat's devtoolset, which provides a new GCC with (most) new C++ features supported, but doesn't introduce dependencies on a new libstdc++.so (so it runs on older systems).

[probonopd]

use something like Red Hat's devtoolset, which provides a new GCC with (most) new C++ features supported, but doesn't introduce dependencies on a new libstdc++.so (so it runs on older systems).

Why doesn't every distribution do it this way by default?

[jwakely]

It creates bigger executables, and not all features of the new GCC are available when using that linkage model, and not everybody needs to be compatible with old, frozen ABIs.

[quocnhat]

Hello, Have you successfully built and compiled ".so" libs cross different systems ( .,i,e: different gcc version) ? I investigated hard on this but failed at all. Which a lot of errors like:
undefined reference to `VTT for std::__cxx11::basic_ostringstream<char, std::char_traits, std::allocator >@GLIBCXX_3.4.21'
This error comes from the incompatible gcc version.