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Re: C++ PATCH: Old ABI compatibility
- To: Mark Mitchell <mark at codesourcery dot com>
- Subject: Re: C++ PATCH: Old ABI compatibility
- From: Jakub Jelinek <jakub at redhat dot com>
- Date: Tue, 11 Jul 2000 19:57:52 +0200
- Cc: gcc-patches at gcc dot gnu dot org
- References: <200007111803.LAA28339@vaio.codesourcery.com>
- Reply-To: Jakub Jelinek <jakub at redhat dot com>
On Tue, Jul 11, 2000 at 11:03:52AM -0700, Mark Mitchell wrote:
>
> This patch restores the old ABI on this test-case provided by Jakub:
>
> class B{};
> class C{};
> class A: public B, public virtual C {};
>
> However, the original code it (Qt) apparently depends on B and A
> having the same address. This is false under the new ABI, and GCC 3.0
> will not support the old ABI. Depending on the layout algorithms in
> the C++ compiler is extremely non-portable.
They started using reinterpret_cast<> and static_cast<> already
as suggested by Jason Merill.
Jakub