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 64A953857C40; Thu,  3 Aug 2023 16:11:46 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 64A953857C40
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1691079106;
	bh=CbYeIMtvgqCMrdQCwJoR96PPeJ09t5yrDUpKjIoN8Po=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=JtWFwaA4CsIowuk2FDDwIC8LcTURnfZ9onVrU7dL4+yb4YuzG0tJTJ2hCJJsBi0/t
	 a7Mf0tcdNkkzjaY2FQJ9E5OgKpuGJF9je+YeHX/26AfdmgHmVYSqRQSMd7a8JCyjPo
	 FSw7r2aQ534O6OEcBcJL0F8Mlsh2aZ527pL1e9JU=
From: "matz at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/110728] should __attribute__((cleanup())) callback
 get invoked for indirect edges of asm goto
Date: Thu, 03 Aug 2023 16:11:45 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: middle-end
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: EH, wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: matz at gcc dot gnu.org
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: 
Message-ID: <bug-110728-4-emdX6cYRsf@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-110728-4@http.gcc.gnu.org/bugzilla/>
References: <bug-110728-4@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=3D110728

--- Comment #11 from Michael Matz <matz at gcc dot gnu.org> ---
(In reply to Michael Matz from comment #9)
> Just for completeness: I agree with Andrew that the initial code example =
in
> comment #0 doesn't show any problem.  The edge from asmgoto to l0 doesn't
> cross
> the scope of the variable, hence no cleanups should be run.  The cleanup
> call that is there is from the edge that leaves the function scope before
> return, and it's placed correctly.

I was reminded that this is incorrect.  Though it isn't documented that way
(AFAICS) the cleanup attribute itself create a scope, as we're using the
try/finally middle-end mechanisms to implement this attribute.  We can't ch=
ange
that behaviour anymore of course, so that's how it has to be: jumping in fr=
ont
of the decl of 'x' _is_ supposed to run the cleanup.

The initial example essentially boils down to:

void test4(void) {
l0:;
        try { /* implicit scope per instantiation of __cleanup__ variable */
                int x __attribute__((cleanup(test4cleanup)));
                asm goto("# %l0"::::l0); /* <-- leaves scope created by x */
        } finally {
                test4cleanup();
        }
}=