From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Sven Joachim Newsgroups: gmane.emacs.bugs Subject: bug#8623: 23.3.50; (woman "git-remote") crashes Date: Fri, 06 May 2011 14:36:04 +0200 Message-ID: <87hb98huq3.fsf@turtle.gmx.de> References: <878vukrjsu.fsf@turtle.gmx.de> <83d3jwnai7.fsf@gnu.org> <87zkn0q2bx.fsf@turtle.gmx.de> <8362pom8ww.fsf@gnu.org> <87pqnwhzmr.fsf@turtle.gmx.de> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: dough.gmane.org 1304685431 30772 80.91.229.12 (6 May 2011 12:37:11 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 6 May 2011 12:37:11 +0000 (UTC) Cc: Paul Eggert , 8623@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Fri May 06 14:37:07 2011 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1QIKHK-00012d-Tn for geb-bug-gnu-emacs@m.gmane.org; Fri, 06 May 2011 14:37:07 +0200 Original-Received: from localhost ([::1]:41976 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QIKHK-0000Uw-F2 for geb-bug-gnu-emacs@m.gmane.org; Fri, 06 May 2011 08:37:06 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:40411) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QIKHI-0000Uq-D4 for bug-gnu-emacs@gnu.org; Fri, 06 May 2011 08:37:05 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QIKHH-0001TS-16 for bug-gnu-emacs@gnu.org; Fri, 06 May 2011 08:37:04 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:33322) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QIKHG-0001TN-Vk for bug-gnu-emacs@gnu.org; Fri, 06 May 2011 08:37:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.69) (envelope-from ) id 1QIKHG-0002Pe-55; Fri, 06 May 2011 08:37:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Sven Joachim Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 06 May 2011 12:37:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 8623 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 8623-submit@debbugs.gnu.org id=B8623.13046853799222 (code B ref 8623); Fri, 06 May 2011 12:37:02 +0000 Original-Received: (at 8623) by debbugs.gnu.org; 6 May 2011 12:36:19 +0000 Original-Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1QIKGY-0002Og-Tu for submit@debbugs.gnu.org; Fri, 06 May 2011 08:36:19 -0400 Original-Received: from mailout-de.gmx.net ([213.165.64.22]) by debbugs.gnu.org with smtp (Exim 4.69) (envelope-from ) id 1QIKGS-0002ON-EA for 8623@debbugs.gnu.org; Fri, 06 May 2011 08:36:17 -0400 Original-Received: (qmail invoked by alias); 06 May 2011 12:36:05 -0000 Original-Received: from p4FF898E7.dip.t-dialin.net (EHLO turtle.gmx.de) [79.248.152.231] by mail.gmx.net (mp022) with SMTP; 06 May 2011 14:36:05 +0200 X-Authenticated: #28250155 X-Provags-ID: V01U2FsdGVkX18l/DhhWGAl3LCMvxAJc9zKfdcA7msfRxFzNMm429 n1aKI8ahRL+13v Original-Received: by turtle.gmx.de (Postfix, from userid 1000) id DBE473F352; Fri, 6 May 2011 14:36:04 +0200 (CEST) In-Reply-To: <87pqnwhzmr.fsf@turtle.gmx.de> (Sven Joachim's message of "Fri, 06 May 2011 12:50:04 +0200") User-Agent: Gnus/5.110017 (No Gnus v0.17) Emacs/23.3.50 (gnu/linux) X-Y-GMX-Trusted: 0 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Fri, 06 May 2011 08:37:02 -0400 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:46267 Archived-At: On 2011-05-06 12:50 +0200, Sven Joachim wrote: > On 2011-05-06 12:15 +0200, Eli Zaretskii wrote: > >>> From: Sven Joachim >>> Cc: 8623@debbugs.gnu.org >>> Date: Thu, 05 May 2011 23:12:18 +0200 >>> >>> $ gcc --version | head -n1 >>> gcc (Debian 4.6.0-6) 4.6.1 20110428 (prerelease) >>> >>> > Also, can you build Emacs without optimizations, and try reproducing >>> > in the unoptimized binary? >>> >>> Alas, the unoptimized binary does not crash. >> >> Darn! Debugging optimized code is pretty much hopeless with current >> versions of GCC. >> >> Paul, could you please take a look at this? Could this be due to the >> same problems with GCC 4.6 optimizations you recently fixed on the >> trunk? If so, we may need similar changes on the release branch. > > I suspect so, because… > >> Sven, could you also try with the trunk build? > > The trunk is fine. I'm already bisecting the problem, but have to leave > in 1.5 hours and will then be unavailable until Sunday. If I find out > the commit which fixed the bug, I'll let you know. The following commit (merged into the trunk as revision 104021) contained the fix: ,---- | revno: 103939.1.42 | committer: Paul Eggert | branch nick: atest | timestamp: Mon 2011-04-25 00:14:46 -0700 | message: | lisp.h: Fix a problem with aliasing and vector headers. | | GCC 4.6.0 optimizes based on type-based alias analysis. For | example, if b is of type struct buffer * and v of type struct | Lisp_Vector *, then gcc -O2 was incorrectly assuming that &b->size | != &v->size, and therefore "v->size = 1; b->size = 2; return | v->size;" must therefore return 1. This assumption is incorrect | for Emacs, since it type-puns struct Lisp_Vector * with many other | types. To fix this problem, this patch adds a new type struct | vector_header that documents the constraints on layout of vectors | and pseudovectors, and helps optimizing compilers not get fooled | by Emacs's type punning. It also adds the macros XSETTYPED_PVECTYPE | XSETTYPED_PSEUDOVECTOR, TYPED_PSEUDOVECTORP, for similar reasons. | * lisp.h (XVECTOR_SIZE): New convenience macro. All previous uses of | XVECTOR (foo)->size replaced to use this macro, to avoid the hassle | of writing XVECTOR (foo)->header.size. | (XVECTOR_HEADER_SIZE): New macro, for use in XSETPSEUDOVECTOR. | (XSETTYPED_PVECTYPE): New macro, specifying the name of the size | member. | (XSETPVECTYPE): Rewrite in terms of new macro. | (XSETPVECTYPESIZE): New macro, specifying both type and size. | This is a bit clearer, and further avoids the possibility of | undesirable aliasing. | (XSETTYPED_PSEUDOVECTOR): New macro, specifying the size. | (XSETPSEUDOVECTOR): Rewrite in terms of XSETTYPED_PSEUDOVECTOR | and XVECTOR_HEADER_SIZE. | (XSETSUBR): Rewrite in terms of XSETTYPED_PSEUDOVECTOR and XSIZE, | since Lisp_Subr is a special case (no "next" field). | (ASIZE): Rewrite in terms of XVECTOR_SIZE. | (struct vector_header): New type. | (TYPED_PSEUDOVECTORP): New macro, also specifying the C type of the | object, to help avoid aliasing. | (PSEUDOVECTORP): Rewrite in terms of TYPED_PSEUDOVECTORP. | (SUBRP): Likewise, since Lisp_Subr is a special case. | * lisp.h (struct Lisp_Vector, struct Lisp_Char_Table): | (struct Lisp_Sub_Char_Table, struct Lisp_Bool_Vector): | (struct Lisp_Hash_Table): Combine first two members into a single | struct vector_header member. All uses of "size" and "next" members | changed to be "header.size" and "header.next". | * buffer.h (struct buffer): Likewise. | * font.h (struct font_spec, struct font_entity, struct font): Likewise. | * frame.h (struct frame): Likewise. | * process.h (struct Lisp_Process): Likewise. | * termhooks.h (struct terminal): Likewise. | * window.c (struct save_window_data, struct saved_window): Likewise. | * window.h (struct window): Likewise. | * alloc.c (allocate_buffer, Fmake_bool_vector, allocate_pseudovector): | Use XSETPVECTYPESIZE, not XSETPVECTYPE, to avoid aliasing problems. | * buffer.c (init_buffer_once): Likewise. | * lread.c (defsubr): Use XSETTYPED_PVECTYPE, since Lisp_Subr is a | special case. | * process.c (Fformat_network_address): Use local var for size, | for brevity. | `---- This commit touches 39 files. How to backport it to the emacs-23 branch is left as an exercise for the reader. Bye, Sven