How to get C++ exceptions to work with PowerPC EABI

[R. Diez]

Hi there:

I have built a GCC 4.5.3 cross-compiler for an embedded PowerPC target, together with binutils-2.21 and newlib 1.19.0, and I cannot get C++ exceptions to work.

I wrote the following test code, but the 'throw' statement ends up calling 'abort' here:

    try
    {
        throw 123;
    }
    catch ( const int a )
    {
        CONSOLE_OUTPUT( "Exception caught: %d", a );
    }
    catch ( ... )
    {
        CONSOLE_OUTPUT( "Catch all reached." );
    }

The call stack looks like this:
  abort() - abort.c:62	
  uw_init_context_1() - unwind-dw2.c:2891	
  _Unwind_RaiseException() - unwind-dw2.c:2891	
  __cxxabiv1::__cxa_throw() - eh_throw.cc:78	

A similar problem was already described in this mailing list:

  http://gcc.gnu.org/ml/gcc-help/2010-01/msg00004.html

However, the information provided there did not help me, as I don't have the necessary knowledge about the GCC internals to understand what's going on.

In my particular case, there is no operating system, so I have full control about what's going on. I can step through the generated assembly code with the debugger if necessary.

Inside main(), I can see the __eabi() call, which in turn calls __init(). I heard the C++ exception support is initialised there, but I don't know what I should provide for it to work properly. Maybe I'm discarding one section too many at the linker, although I did try to keep the .eh_frame ones. Or maybe I'm not initialising some global register properly in my start-up assembly code.

Can someone provide me with step-by-step instructions on how to setup the necessary C++ exception support framework? What could I be missing?

Please copy me on the answer, as I'm not subscribed to this list.

Many thanks,
  R. Diez