Add catching C++ exception support to dwarfeh.d

[WalterBright]

Requires:
dlang/dmd#5342

[ibuclaw]

Maybe add a pointer comparison before this to shortcut calling do_catch? If sti == tt then it's a direct match.

[IgorStepanov]

It's done inside __do_catch:

bool __class_type_info::
__do_catch (const type_info *thr_type,
            void **thr_obj,
            unsigned outer) const
{
  if (*this == *thr_type)
    return true;
  if (outer >= 4)
    // Neither `A' nor `A *'.
    return false;
  return thr_type->__do_upcast (this, thr_obj);
}

[ibuclaw]

That is not actually true. (*this == *thr_type) calls operator==.

[IgorStepanov]

operator== in my libstdc++ looks like

bool std::type_info::
operator== (const std::type_info& arg) const
{
  return (&arg == this) || (__builtin_strcmp (name (), arg.name ()) == 0);
}

However in other versions it may differ.

[ibuclaw]

You may find that it's been that way for a very long time. C++ is not something that simply changes.

[WalterBright]

Maybe add a pointer comparison before this to shortcut calling do_catch? If sti == tt then it's a direct match.

Done, but given all the other code executed for an exception, I doubt the difference would be measurable.

[IgorStepanov]

BTW, will be this exception handling work with some another c++ compilers? clang++? intel c++ compiler?

[WalterBright]

will be this exception handling work with some another c++ compilers? clang++? intel c++ compiler?

My understanding is that they are binary compatible with g++, so they should work.

[IgorStepanov]

My understanding is that they are binary compatible with g++, so they should work.

Are they use the same libstdc++ implementation? Otherwise there can be another virtual method order in std::type_info for example.

[WalterBright]

You can be binary compatible and yet have a different implementation. Again, my understanding is they are binary compatible.

[IgorStepanov]

You can be binary compatible and yet have a different implementation. Again, my understanding is they are binary compatible.

Sounds good. It remains to deal with dmc and Visual Studio :)

[andralex]

this line in desperate need of auto

[andralex]

thx!