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 4AEA43857C77; Sun,  3 Dec 2023 17:04:08 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4AEA43857C77
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1701623048;
	bh=lnVIWJliviavjDHQgYIcH1Uz0kxV/1lyfYzO0zQ3C2U=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=oduqVQLbbysCKWeZYAGX2bsg0DnYpkBjpvhySBGUUBmDsgQOuC0mQwD2fvXwz5sVY
	 9dgn7cAAK2blywpczP92tO0wat+xd7LpMI7ylEcBPVFb40f8FeAd8sYzbOgBA7eIRm
	 lhfjU9/faGg4AEJWNz/s8/lPSV95Qj16KzUPxrEY=
From: "alx at kernel dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/112833] Missing warnings on restrict misuse
Date: Sun, 03 Dec 2023 17:04:07 +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: 13.2.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: alx at kernel 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: 
Message-ID: <bug-112833-4-3GOFkccFu4@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-112833-4@http.gcc.gnu.org/bugzilla/>
References: <bug-112833-4@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=3D112833

--- Comment #1 from Alejandro Colomar <alx at kernel dot org> ---
Oops, in the reproducer from above, I should only expect a warning at call
site.  The definition is correct, since all parameters are restrict, so it's
free to copy one to the other.

Here's a reproducer where the call is fine, but the definition is wrong, and
the compiler doesn't realize:


$ cat restrict.c=20
#include <string.h>

long bogus2_strtol(const char *s, char **restrict ep, int base);

int
main(void)
{
        char buf[3] =3D "foo";
        char *p =3D buf;

        bogus2_strtol(p, &p, -42);
}

long
bogus2_strtol(const char *s, char **restrict ep, int base)
{
        memcpy(*ep, s, 1);
        return base;
}
$ gcc -Wall -Wextra restrict.c -fanalyzer
$ gcc -Wall -Wextra restrict.c -fanalyzer -O3=