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 5B73A3858C41; Wed, 17 May 2023 15:14:15 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5B73A3858C41
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1684336455;
	bh=DnjhFS78i5Is0Vn5PWEg6/ssVqcT73loWj8WuAOvnFE=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=Wr1CC+UiQ1aOjN5rvB8mGkW4fiG+V8iPS+Xf5eALupCMuf8osTzKqLTv16asiVSPm
	 tZU1F7hm7+QFkpjfpUb3a1v3IKYeeYat4x7VM7Cs9cn92Oa+4DpLqtGHJfxPN6y86x
	 bmBX/uVmQEPmxebTeiHVBZoWqMThntvtL/IeVeyA=
From: "xry111 at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug analyzer/109570] detect fclose on unopened or NULL files
Date: Wed, 17 May 2023 15:14:15 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: analyzer
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: xry111 at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: dmalcolm at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-109570-4-JGfgAraMsM@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-109570-4@http.gcc.gnu.org/bugzilla/>
References: <bug-109570-4@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=3D109570

--- Comment #6 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
(In reply to Christophe Lyon from comment #5)
> Not sure how to update/fix the testcases though?
> Since they get the declaration of fclose from stdio.h, we'd need to make
> dg-error conditional to the glibc version in use, which seems unpractical.
>=20
> Should we instead remove #include <stdio.h> and provide suitable
> declarations in the testcase?

I guess we need to change

  return ferror (f) || fclose (f) !=3D 0;

to

  return !f || ferror (f) || fclose (f) !=3D 0;

Because "failing to check if the file is opened successfully" is definitely=
 a
bug, and these tests are intended not to raise warnings for a bug-free prog=
ram.

BTW ferror(f) segfaults as well when f is NULL, so IMO we should mark it
nonnull in Glibc as well.=