From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30790 invoked by alias); 22 Dec 2007 18:03:04 -0000 Received: (qmail 30726 invoked by uid 48); 22 Dec 2007 18:02:52 -0000 Date: Sat, 22 Dec 2007 18:03:00 -0000 Message-ID: <20071222180252.30725.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug c++/33802] g++ says `z' is used uninitialized but this is not true In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "manu at gcc dot gnu dot org" Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2007-12/txt/msg02060.txt.bz2 ------- Comment #4 from manu at gcc dot gnu dot org 2007-12-22 18:02 ------- (In reply to comment #1) > Created an attachment (id=14366) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=14366&action=view) [edit] > (Big) testcase that allows to reproduce > I can't compile the testcase with cc1plus 4.3 revision 130379. I get a lot of warnings and a few errors. Perhaps I need to include something else ? Anyway, the relevant SSA is: # BLOCK 195, starting at line 37941 # PRED: 194 (true) :; # VUSE ; [/home/manuel/src/pr33802.C : 37941] z.1689D.225422_240 = zD.225363; [/home/manuel/src/pr33802.C : 37941] *toD.225359_119 = z.1689D.225422_240; [/home/manuel/src/pr33802.C : 37942] D.225423_241 = rD.225364_141; goto (); # SUCC: 213 (fallthru) Wuninitialized cannot handle virtual operands, so it doesn't understand that z could have been initialized. Funny enough, this is exactly the opposite of bug 179 but both SSA dumps look very similar. I really don't understand why we warn in one case and not in the other. By the way, what does # VUSE ; exactly means? I cannot find any other mention of zD.225363_219. -- manu at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|0000-00-00 00:00:00 |2007-12-22 18:02:52 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33802