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 51E8B3858282; Thu, 28 Mar 2024 05:28:54 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 51E8B3858282
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1711603734;
	bh=+IEYO8sUMWzl/fTwiNpsqkG5cgOXyXbTHEDsdmYBx4M=;
	h=From:To:Subject:Date:From;
	b=PMvlPFx+K32vVXFOGMalz8HEf+R8QVsFSnX4bWAIb/Y0BOqlkoBDWh+zvWvep/FDQ
	 a8K7n2/+neMNmZjX/neQAIx2rQ/1YWYojpVXCLn9zAvvQoBBNkJ7diXqMYf+POk7xV
	 SWKgsUwHesxoMLun55O6ZeCjfteTSmnqvb2+mzD8=
From: "vt at altlinux dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/114507] New: FR: Randomize order of evluation of function of
 arguments
Date: Thu, 28 Mar 2024 05:28:53 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c
X-Bugzilla-Version: unknown
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: vt at altlinux dot org
X-Bugzilla-Status: UNCONFIRMED
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: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-114507-4@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=3D114507

            Bug ID: 114507
           Summary: FR: Randomize order of evluation of function of
                    arguments
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vt at altlinux dot org
  Target Milestone: ---

There is class of bugs when, for example, printf is called with several
functions that output to the same static buffer overwriting each others res=
ult.
This could be hard to detect in legacy code, for example there is nested ca=
lls
invisible from top level functions, also compiler tend to create the same c=
all
order, so if overwriting is order dependent it could be undetected for years
and appear on some rare architecture when compiler reorder calls [1].

To detect this kind of bugs it would be useful to have compiler option to
reorder function arguments evaluation randomly. With this test suites will =
have
a _chance_ to detect the bugs even on one architecture.

[1] https://lore.kernel.org/all/20240323091717.dtsioyvjnhl5dtyv@altlinux.or=
g/=