Re: C++ Exception handlin on mips [was Re: Mozilla...]

["Martin v. Loewis" <martin@v.loewis.de>]

> > Thanks for the testcase.  I meant to make one when alpha started having EH
> > problems awhile back, but never got to it....Matthias, I believe this one
> > will also catch the case that I saw on alpha.
> 
> Interesting enough the program works as expected when compiled with
> -static like "g++ -ggdb -o throw-2.95 throw.cc" (linker bug?)

Unlikely. The original gdb "backtrace" indicated that somebody was
jumping to address 0. I think potential causes are:

1. dynamic initialization of a shared library has not been carried
   out. It would be interesting to verify that all shared libraries
   involved do have proper .init/.fini code, i.e. have been linked
   with the proper crt files.

2. dynamic initialization had initialized a different location than
   used when throwing the exception. That problem is known to occur
   when mismatching variants of the EH code in libgcc.a have been
   integrated into different shared libraries (or if both a libcc_s.so
   and copies of libgcc.a are used inconsistently): That would result
   in multiple copies of static variables of the EH variables. 

   This isn't a problem as long as all libgcc functions resolve to the
   same shared object, but is a problem if they resolve to different
   libgcc copies; this happens when an out-of-libc.so copy has
   additional functions that are not in libgcc.

3. the dynamic linker has failed to perform all relocations
   properly. This is also unlikely.

Regards,
Martin