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Date: Fri, 8 Sep 2000 23:00:49 -0400
From: Chris Faylor <cgf AT cygnus DOT com>
To: "Cygwin (E-mail)" <cygwin AT sourceware DOT cygnus DOT com>
Subject: Re: problem with dynamic_cast
Message-ID: <20000908230049.A21412@cygnus.com>
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References: <B0016417505 AT mzdy17 DOT allegro DOT net> <20000908124631 DOT C13006 AT cygnus DOT com>
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In-Reply-To: <20000908124631.C13006@cygnus.com>; from cgf@cygnus.com on Fri, Sep 08, 2000 at 12:46:31PM -0400

On Fri, Sep 08, 2000 at 12:46:31PM -0400, Chris Faylor wrote:
>On Fri, Sep 08, 2000 at 10:18:42AM -0400, Fleischer, Karsten (K.) wrote:
>>How about including the stub libraries in the distribution, rather than the
>>symlinks?
>
>The reason for the symlinks is that some packages search libc.a and libm.a
>for symbols.
>
>If linking libc.a twice causes problems, then it *is* a bug in either gcc or
>ld.
>
>Mumit had vowed once to fix this problem but then he disappeared...

Ok, I looked into this.  It is a linker problem.  Specifying -lm or -lc on
the command line causes ld to put symbols into the import section in improperly
sorted order.

This confuses the Windows "dynamic loader" (and I use the term loosely) so that
certain function calls (namely strcmp and strlen) are not resolved.  So when
a function in libgcc needs to call strcmp it ends up jumping into unallocated
memory, causing a SIGSEGV.

That's the analysis.  I have no idea how to fix this, but I've sent some details
to DJ in the hopes that he'll be able to do something about this.

cgf

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