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Re: gcc 3.3


>The hope is that yes, C++ compiled with gcc 3.3 will be binary compatible
>with 3.2.  However, there's no guarantees; if gcc 3.2 turns out to have
>ABI bugs, like 3.1 did, then they will need to be fixed.  The hope is
>that all the ABI bugs have now been caught, but no-one knows for sure.

PR 7442 submitted today reports more C++ ABI issues.  This one covers problems
with the cxxabi.h file.

There are also known back end problems that haven't been fixed yet.  We
use .init/.fini sections instead of .init_array/.fini_array sections for
static constructors/destructors.  We use .gnu.linkonce sections instead
of ELF COMDAT for template instantiation.  These should be fixable without
breaking backwards compatibility in theory, but we haven't tried yet.

I think we will continue to find C++ ABI bugs for a while.  There hasn't been
any attempt to verify the implementation against the specification.  I don't
think we should claim a stable C++ ABI until it is possible to link C++ code
compiled by gcc with C++ code compiled by other compilers, because only then
will we be able to test it.

Jim


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