symbols.map: ODR violations

[jengelh]

$ nm libmirserver.so.61
0000000000338568 b _ZZNSt19_Sp_make_shared_tag5_S_tiEvE5__tag

Hiding symbols is a problem, as this precludes the linker from collapsing multiple definitions of the same symbol, and breaking the One Definition Rule. In practice, this affects e.g. glibc's std::string::_M_dispose, which references a static variable:

if (this == &_S_empty_rep())

Because address comparisons no longer return expected results, that particular spot ends up calling the wrong deallocator and corrupts the program state.

The following symbols must be unhidden:

std::*::_S_*;
guard?variable?for?std::*;
typeinfo?for?std::*;
VTT?for?std::*;
construction?vtable?for?std::*;
vtable?for?std::*;
non-virtual?thunk?to?std::*;
virtual?thunk?to?std::*;

This needs to happen for a bunch of libraries, so:

• std::
• boost::
• YAML:: (used by libmiral)

Furthermore, tools/symbols_map_generator/main.py also needs to insert construction vtable for ....