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 8EF2E3858C74; Fri, 28 Apr 2023 05:25:00 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8EF2E3858C74
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1682659500;
	bh=w8qKHBftVDGsSbOJUJrFlhroB4xu/a5NpZ7YSC/2luA=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=uGGt/m3LTEe8g0sy/h7R7nJm/GXGhfYskKYN5g+U+HNU2XLy9VlRJzru4v3ZQqPBa
	 VGZjcDLg6UrkVAnMehGRQAb2c/9sS8OgGFseMHnTl6umMZh4HM3CeQ1tBjqcoWSvNQ
	 pZWQhr5Yh+UNivN9ePigZM0OcfjdbYg562XLvV9o=
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/105523] Wrong warning array subscript [0] is outside
 array bounds
Date: Fri, 28 Apr 2023 05:25:00 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: diagnostic
X-Bugzilla-Severity: normal
X-Bugzilla-Who: pinskia at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: saaadhu at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-105523-4-3Kw9CcJ23e@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-105523-4@http.gcc.gnu.org/bugzilla/>
References: <bug-105523-4@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=3D105523

--- Comment #32 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to LIU Hao from comment #31)
> (In reply to Andrew Pinski from comment #24)
> > The warning is there for the above case really (and similar ones with s=
truct
> > offsets). Where you originally have a null pointer and have an offset f=
rom
> > there; by the time the warning happens, the IR does not know if it was
> > originally from an offset of a null pointer or if the value was written=
 in.
>=20
> I understand that completely, but it does not justify the confusion.
> Something like 'warning: array subscript 0 is outside array bounds of' sa=
ys
> nothing about null pointers, and is thus misleading.=20

Actually since GCC 13, there is an additional note specifically to fix that
misleading part:
cc1plus: note: source object is likely at address zero=