From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: YAMAMOTO Mitsuharu Newsgroups: gmane.emacs.bugs Subject: bug#8227: possibly uninitialized variables in update_window_fringes Date: Fri, 11 Mar 2011 10:31:27 +0900 Organization: Faculty of Science, Chiba University Message-ID: References: <4D79628F.3030106@cs.ucla.edu> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII X-Trace: dough.gmane.org 1299807434 826 80.91.229.12 (11 Mar 2011 01:37:14 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 11 Mar 2011 01:37:14 +0000 (UTC) Cc: 8227@debbugs.gnu.org To: Paul Eggert Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Fri Mar 11 02:37:08 2011 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1PxrHv-0006gO-Mt for geb-bug-gnu-emacs@m.gmane.org; Fri, 11 Mar 2011 02:37:08 +0100 Original-Received: from localhost ([127.0.0.1]:41851 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PxrHu-0005jL-Up for geb-bug-gnu-emacs@m.gmane.org; Thu, 10 Mar 2011 20:37:07 -0500 Original-Received: from [140.186.70.92] (port=37454 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PxrHm-0005iV-8d for bug-gnu-emacs@gnu.org; Thu, 10 Mar 2011 20:36:59 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PxrHl-0005GY-37 for bug-gnu-emacs@gnu.org; Thu, 10 Mar 2011 20:36:58 -0500 Original-Received: from debbugs.gnu.org ([140.186.70.43]:55665) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PxrHl-0005GS-0K for bug-gnu-emacs@gnu.org; Thu, 10 Mar 2011 20:36:57 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.69) (envelope-from ) id 1PxrCz-0002pe-Rs; Thu, 10 Mar 2011 20:32:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: YAMAMOTO Mitsuharu Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 11 Mar 2011 01:32:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 8227 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 8227-submit@debbugs.gnu.org id=B8227.129980710010858 (code B ref 8227); Fri, 11 Mar 2011 01:32:01 +0000 Original-Received: (at 8227) by debbugs.gnu.org; 11 Mar 2011 01:31:40 +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 1PxrCd-0002p5-Ev for submit@debbugs.gnu.org; Thu, 10 Mar 2011 20:31:39 -0500 Original-Received: from mathmail.math.s.chiba-u.ac.jp ([133.82.132.2]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1PxrCa-0002oo-J5 for 8227@debbugs.gnu.org; Thu, 10 Mar 2011 20:31:38 -0500 Original-Received: from church.math.s.chiba-u.ac.jp (church [133.82.132.36]) by mathmail.math.s.chiba-u.ac.jp (Postfix) with ESMTP id D89A5C055D; Fri, 11 Mar 2011 10:31:27 +0900 (JST) In-Reply-To: <4D79628F.3030106@cs.ucla.edu> User-Agent: Wanderlust/2.14.0 (Africa) SEMI/1.14.6 (Maruoka) FLIM/1.14.8 (=?UTF-8?Q?Shij=C5=8D?=) APEL/10.6 Emacs/22.3 (sparc-sun-solaris2.8) MULE/5.0 (SAKAKI) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Thu, 10 Mar 2011 20:32:01 -0500 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: , Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:44896 Archived-At: >>>>> On Thu, 10 Mar 2011 15:45:19 -0800, Paul Eggert said: > I found this problem by compiling Emacs with GCC's -Wuninitialized flag. > The following code in the Emacs trunk src/fringe.c's > update_window_fringes function might be using uninitialized > variables: > int top_row_ends_at_zv_p, bot_row_ends_at_zv_p; > ... > if (top_ind_rn >= 0) > { > ... > top_row_ends_at_zv_p = row->ends_at_zv_p; > } > ... > for (y = w->vscroll, rn = 0; > y < yb && rn < nrows; > y += row->height, rn++) > { > ... > if (WINDOW_LEFT_FRINGE_WIDTH (w) == 0) > ... > else if (row->left_user_fringe_bitmap != NO_FRINGE_BITMAP) > ... > else if ((!row->reversed_p && row->truncated_on_left_p) > || (row->reversed_p && row->truncated_on_right_p)) > ... > else if (row->indicate_bob_p && EQ (boundary_top, Qleft)) > { > left = ((row->indicate_eob_p && EQ (boundary_bot, Qleft)) > ? LEFT_FRINGE (1, Qtop_bottom, top_row_ends_at_zv_p) > : LEFT_FRINGE (2, Qtop, 0)); > ... > } > The last assignment uses top_row_ends_at_zv_p, but it's not clear > from the previous tests that top_row_ends_at_zv_p must be initialized. > There is a similar issue with bot_row_ends_at_zv_p. No problem. top_ind_rn is set to a non-negative value whenever row->indicate_bob_p is set. for (y = w->vscroll, rn = 0; y < yb && rn < nrows; y += row->height, ++rn) { ... if (!row->mode_line_p) { if (top_ind_rn < 0 && row->visible_height > 0) { if (MATRIX_ROW_START_CHARPOS (row) <= BUF_BEGV (XBUFFER (w->buffer)) && !MATRIX_ROW_PARTIALLY_VISIBLE_AT_TOP_P (w, row)) row->indicate_bob_p = !NILP (boundary_top); else row->indicate_top_line_p = !NILP (arrow_top); top_ind_rn = rn; } YAMAMOTO Mitsuharu mituharu@math.s.chiba-u.ac.jp