From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id AD1903858C53; Fri, 26 Jan 2024 01:01:46 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org AD1903858C53
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1706230906;
	bh=BmTJDZ2G57eV2hVsogTWV7egEjgs8gp747qaam0gK48=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=LT1WwT2YhvyPWYsx+/W0e6XS84Ewp2RREs6ffZtjIbQXwcaaIEusG+s2amJ8yOkHt
	 qCq/p6ovyuNnLy5DJLPdnvXi5UNtuhh/36jhXtQ+u3sL2DRd5J86mUQihWzr7ExVXj
	 m2lDLPv0J3aP7pLRkklf3tu99y56uL0deThsDDtQ=
From: "gabravier at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/29970] mixing ({...}) with VLA leads to massive breakage
Date: Fri, 26 Jan 2024 01:01:41 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c
X-Bugzilla-Version: 4.3.0
X-Bugzilla-Keywords: ice-on-valid-code, patch, stmt-expr, wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: gabravier at gmail dot com
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: cc
Message-ID: <bug-29970-4-KdZGBcNR4R@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-29970-4@http.gcc.gnu.org/bugzilla/>
References: <bug-29970-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D29970

Gabriel Ravier <gabravier at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gabravier at gmail dot com

--- Comment #19 from Gabriel Ravier <gabravier at gmail dot com> ---
Can also confirm this myself as I've also encountered this ICE in this code:

#include <stdio.h>

#define each(item, array) \
(typeof(*(array)) *foreach_p =3D (array), *foreach_p2 =3D foreach_p, (item)=
 =3D {}; \
foreach_p < &((foreach_p2)[sizeof(array)/sizeof(*array)]); \
++foreach_p)if((__builtin_memcpy(&(item), foreach_p, sizeof((item)))), 0){}=
else

#define range1(_stop) (({ \
        typeof(_stop) stop =3D _stop; \
        struct{typeof((stop)) array[stop];}p =3D {}; \
        if(stop < 0){ \
                for(size_t i =3D 0; i > stop; --i) \
                        p.array[-i] =3D i; \
        }else{ \
                for(size_t i =3D 0; i < stop; ++i) \
                        p.array[i] =3D i; \
        } \
        p; \
}).array)

int main(){
        char group[][4] =3D {
                "egg",
                "one",
                "two",
                "moo",
        };
        for each(x, group){
                puts(x);
        }
        return sizeof(range1(6));
}

which I was able to minify to:

void f()
{
  (void)({
    int x =3D 1;
    struct {
      int array[x];
    } p;
    p;
  });
}

which roughly matches what testcase 2 does.=