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Date: Sun, 20 May 2007 17:11:25 +0200
From: Joerg Sonnenberger <joerg@britannica.bec.de>
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Subject: Re: HEADS UP: OpenSSL problems after GCC 4.2 upgrade
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On Sun, May 20, 2007 at 05:03:57PM +0200, Dag-Erling Smørgrav wrote:
> Alexander Kabaev <kabaev@gmail.com> writes:
> > there were several reports of OpenSSL being broken when compiled with
> > GCC 4.2. It turns out OpenSSL uses function casting feature that was
> > aggressively de-supported by GCC 4.2 and GCC goes as far as inserting
> > invalid instructions ON PURPOSE to discourage the practice.
> 
> Is there a web page somewhere (or an archived mailing list discussion,
> or whatever) which discusses the issue and explains the rationale for
> intentionally generating incorrect code?

It happened in the past, e.g. with va_arg. In that case gcc creates
explicit abort() calls, because it can't refuse the code (syntactically correct
C), but the runtime behaviour is completely implementation defined.

Joerg