I'm using C::B 1.0RC2 the newst nightly build
Those are two mutually exclusive things.
However, it doesn't matter in this case, since it is not strictly a Code::Blocks related problem, but a compiler-related problem.
The
def file that you posted contains two notable things:
1. CPP
2. double-underscores
First of all, sharing C++ libraries between different compilers is problematic at best, as they have different ABIs. You should make everything
extern "C" if you want to have any chance to do cross-compiler acrobatics at all. That will force function calls to something every compiler does the same way.
Second, those double-underscores are a known issue when converting Microsoft DLLs to MinGW.
I don't know whether you can use Borland libraries in gcc at all, but these double-underscores are practically guaranteed to be the same issue as with Microsoft Dlls. The "cookbook" way to get rid of them would be
pexports cbDll.dll | sed 's/^_//' > cbDll.def, as found on Mark Schoenberg's site.
If nothing helps, you may have to go through a more painful process, by editing the
def file by hand to the correct format.