g++5 ABI test tool
==================

This is a simple tool to test a system for g++5's glibmm at runtime.

GCC5.1 introduced a new ABI for the C++ standard library.
The old 3.4 .. 5.0 ABI is not compatible. By default gcc provides a
dual ABI, so testing libstdc++ itself is not sufficient.


Some GNU/Linux distributions systems switched to the new ABI already
and compile *plugins* with the new gcc.

If a plugin uses a c++ library that is also shipped with ardour-bundles,
the ABI of that library must match. Currently known cases: gtkmm, glibmm.

e.g. Ingen or eq10q provided by a distro compiled with gcc5 will not
load in Ardour from ardour.org compiled with gcc4 because ardour
ships an incompatible gtkmm, glibmm, cairomm, ...

Likewise Ardour gcc5-compiled binaries will fail to load plugins that
are compiled with gcc4.

This simiple tool `gcc-glibmm-abi-check` checks for gcc4/gcc5 specific
symbols in libglibmm (a common denominator C++ lib), it is intended
to be run when deploying ardour binaries.


References
----------

https://gcc.gnu.org/onlinedocs/libstdc++/manual/using_dual_abi.html
https://wiki.debian.org/GCC5
https://mail.gnome.org/archives/gtkmm-list/2015-June/thread.html
