X-Recipient: archive-cygwin AT delorie DOT com
DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; q=dns; s=
	default; b=ylNIzR7smszgqLqwzIp1cABLdRaToYTKw25d+rPsITcDH1f3C+B1Q
	hwnrWBPvt6WbZe2OuZ88GFWG7FjjrIPJwI/J6hCiHBda6r/c2uDl4NX3rwqrkOup
	KK7xnX7lBXttG7OQ7csDJMejOlrPkQU9PGiO7n8W+7z2ifT70t2keE=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; s=default;
	 bh=PaxKe6uCrVnracLZka90Fzl1AVc=; b=ApmkVULBGMARDlqEeX6Sp8NcfwW6
	WGKjDAdQQqiCS1Qj0dXQNXkYZo6gyqqheZeUKdkfQwGdv3qANM3K6RLG8gDf2kUm
	47zzxoif9fWvt83nQPKjBthfigLcJldE5Nq84Vi4kltqqRPgoZsnVGjR0Vjn4OtP
	Eofj4ad77khx56Q=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Authentication-Results: sourceware.org; auth=none
X-Spam-SWARE-Status: No, score=-100.9 required=5.0 tests=BAYES_00,GOOD_FROM_CORINNA_CYGWIN,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.2 spammy=Habiel, habiel
X-HELO: mout.kundenserver.de
Date: Mon, 4 Feb 2019 15:27:37 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: 32 bit vs 64 bit Cygwin, followup
Message-ID: <20190204142737.GO3532@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <CABHT96207sag6z7LMMDiBQciu-B3o7zFoOkYLw3OOSi_S=Kckg AT mail DOT gmail DOT com> <db507cae25f6f4b20af039bf3931e727d9614f61 DOT camel AT redhat DOT com> <CABHT963855jsHu0r=1f0dHye9k+uGb21EYkSj1SS+06V0bhsjg AT mail DOT gmail DOT com> <20181129085816 DOT GV30649 AT calimero DOT vinschen DOT de> <CABHT962ok6x121SezynVto2k1DoQ6T6Wj3J+Nq9O+AQs+uNeRQ AT mail DOT gmail DOT com> <20181129163327 DOT GD30649 AT calimero DOT vinschen DOT de> <CABHT961E1J3z_QjDr_PQu6gerUqsNnHN6NMBSBNas=4mbcNBiQ AT mail DOT gmail DOT com> <CABHT961Uinr8yQNkPqmUzg5amsRCppBK1DYcZaptz-iczb17Og AT mail DOT gmail DOT com> <20190202170508 DOT GB3532 AT calimero DOT vinschen DOT de> <CABHT963swdYVKtN-3cZLYfUAK6eQ8V+asZgOGKRqY3LoCWDkOw AT mail DOT gmail DOT com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;	protocol="application/pgp-signature"; boundary="wLAMOaPNJ0fu1fTG"
Content-Disposition: inline
In-Reply-To: <CABHT963swdYVKtN-3cZLYfUAK6eQ8V+asZgOGKRqY3LoCWDkOw@mail.gmail.com>
User-Agent: Mutt/1.10.1 (2018-07-13)

--wLAMOaPNJ0fu1fTG
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Feb  4 09:16, Sam Habiel wrote:
> >That's not GCC fault.  You're running varargs, written for the standard
> >stack layout of the MSABI target from a function with a stack laid out
> >in SYSV ABI.  That can't work.
>=20
> I did some research to see how to write my own version of varargs (the
> code base is already instrumented to do different versions of varargs
> based on operating system). What I noticed though is that after
> disassembling code for win64 abi vs sysv abi, it seems like gcc/crt is
> attempting to do the right thing. There is different code for sysv vs
> win64 for va_start.
>=20
> sysv:
> 10        va_list vl;
> 11        va_start(vl,n);
>    0x00000001004010e4 <+100>:   movl   $0x8,-0xc8(%rbp)
>    0x00000001004010ee <+110>:   movl   $0x30,-0xc4(%rbp)
>    0x00000001004010f8 <+120>:   lea    0x10(%rbp),%rax
>    0x00000001004010fc <+124>:   mov    %rax,-0xc0(%rbp)
>    0x0000000100401103 <+131>:   lea    -0xb0(%rbp),%rax
>    0x000000010040110a <+138>:   mov    %rax,-0xb8(%rbp)
>=20
> win64:
> 10        va_list vl;
> 11        va_start(vl,n);
>    0x00000001004010a3 <+35>:    lea    0x18(%rbp),%rax
>    0x00000001004010a7 <+39>:    mov    %rax,-0x18(%rbp)
>=20
> So there may be a incomplete support for varargs for the sysv abi--but bu=
ggy.
>=20
> I attached the disassembly as well as the testing programs for your conve=
nience.

There's nothing for me to do here.  You still have to make sure
to choose the right varargs version and if there's really a bug,
you really should report it to GCC.


Corinna

--=20
Corinna Vinschen
Cygwin Maintainer

--wLAMOaPNJ0fu1fTG
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=ZHtt
-----END PGP SIGNATURE-----

--wLAMOaPNJ0fu1fTG--