From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Simplify internal_catch() Date: Sat, 31 Dec 2016 13:29:06 -0800 Organization: UCLA Computer Science Department Message-ID: References: <87bmvwlfzo.fsf@gmail.com> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------0958C3B487C8E8F28B5D9013" X-Trace: blaine.gmane.org 1483219772 13175 195.159.176.226 (31 Dec 2016 21:29:32 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 31 Dec 2016 21:29:32 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 Cc: Chris Gregory , emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Dec 31 22:29:28 2016 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cNRDM-0001uN-3G for ged-emacs-devel@m.gmane.org; Sat, 31 Dec 2016 22:29:20 +0100 Original-Received: from localhost ([::1]:45405 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cNRDR-00034t-26 for ged-emacs-devel@m.gmane.org; Sat, 31 Dec 2016 16:29:25 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:50286) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cNRDH-00034m-U4 for emacs-devel@gnu.org; Sat, 31 Dec 2016 16:29:17 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cNRDC-00050j-Ta for emacs-devel@gnu.org; Sat, 31 Dec 2016 16:29:15 -0500 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:40892) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cNRDC-0004xx-Jg for emacs-devel@gnu.org; Sat, 31 Dec 2016 16:29:10 -0500 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 2FEC016006C; Sat, 31 Dec 2016 13:29:08 -0800 (PST) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id vqr98m04KsK3; Sat, 31 Dec 2016 13:29:07 -0800 (PST) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 20D4E160073; Sat, 31 Dec 2016 13:29:07 -0800 (PST) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id m-L2QzhlDY-a; Sat, 31 Dec 2016 13:29:07 -0800 (PST) Original-Received: from [192.168.1.9] (unknown [47.153.178.162]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id F0E2016006C; Sat, 31 Dec 2016 13:29:06 -0800 (PST) In-Reply-To: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 131.179.128.68 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:211047 Archived-At: This is a multi-part message in MIME format. --------------0958C3B487C8E8F28B5D9013 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable Stefan Monnier wrote: > At least I know Richard made me undo some "Lisp_Object foo =3D ..." yea= rs > ago, saying that we shouldn't do that because it fails to compile in > some cases (presumably when you used some specific compiler and you als= o > asked for Lisp_Object to be a union rather than an int). > I did not heed his advice very eagerly, to tell you the truth. Many pre-C89 compilers indeed did not support union initializers (i.e., '= union u=20 x =3D { something };', so perhaps there was some confusion about what wor= ked and=20 what didn't. Anyway, that water passed under the bridge long ago. In reviewing this patch, I noticed some other confusion in this area that= I=20 introduced in 2013 while pacifying gcc -Wclobbered, and which I think you= asked=20 about but I didn't understand your question at the time (sorry). I attemp= ted to=20 fix the problem just now by installing the attached patch, which undoes C= hris's=20 simplification and then reworks the setjmp calls to use a local rather th= an a=20 global. This avoid a need to load from a static variable in the normal fl= ow of=20 execution. --------------0958C3B487C8E8F28B5D9013 Content-Type: text/plain; charset=UTF-8; name="0001-Clarify-internal_catch-etc.txt" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="0001-Clarify-internal_catch-etc.txt" RnJvbSA1MzVlZjE4ZWQ1MjM4NjJkYjQwNWQyMmVjNGJlYTBiYmZkNDE3MmNlIE1vbiBTZXAg MTcgMDA6MDA6MDAgMjAwMQpGcm9tOiBQYXVsIEVnZ2VydCA8ZWdnZXJ0QGNzLnVjbGEuZWR1 PgpEYXRlOiBTYXQsIDMxIERlYyAyMDE2IDEzOjEwOjM4IC0wODAwClN1YmplY3Q6IFtQQVRD SF0gQ2xhcmlmeSBpbnRlcm5hbF9jYXRjaCBldGMuCk1JTUUtVmVyc2lvbjogMS4wCkNvbnRl bnQtVHlwZTogdGV4dC9wbGFpbjsgY2hhcnNldD1VVEYtOApDb250ZW50LVRyYW5zZmVyLUVu Y29kaW5nOiA4Yml0CgpUaGUgcmVjZW50IGNoYW5nZSB0byBpbnRlcm5hbF9jYXRjaCBhbmQg ZnJpZW5kcyByZWxpZWQgb24gc29tZQpjb25mdXNpb24gSSBpbnRyb2R1Y2VkIHRvIHRoZSBj b2RlIGluIDIwMTMuICBBdHRlbXB0IHRvIGZpeAp0aGUgY29uZnVzaW9uIGJ5IGNsYXJpZnlp bmcgdGhlIGNvZGUgaW5zdGVhZC4gIFRoaXMgc2F2ZXMgYW4KaW5zdHJ1Y3Rpb24gYW5kIGEg 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