X-Recipient: archive-cygwin AT delorie DOT com X-SWARE-Spam-Status: No, hits=-0.7 required=5.0 tests=AWL,BAYES_00,SPF_NEUTRAL X-Spam-Check-By: sourceware.org Message-ID: <4EE22156.4080402@cs.utoronto.ca> Date: Fri, 09 Dec 2011 09:55:18 -0500 From: Ryan Johnson User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: cygwin AT cygwin DOT com Subject: Re: gcc-4.5.3 segfaults wrt alloca References: <20111209105801 DOT GA10388 AT po8371> In-Reply-To: <20111209105801.GA10388@po8371> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com On 09/12/2011 5:58 AM, Denis Excoffier wrote: > I use the latest packages and cygwin snapshots. The problem described > below began several snapshots in the past, around beginning of December. > > The following program, with static allocation of a reasonable amount > of data, segfaults, maybe in alloca(). With a smaller size > (eg 10000) it's ok. With new/malloc (even with 100 times more) it's > ok. With C or C++. 100% reproducible. > unsigned int const SIZE = 689471; > int foo[SIZE]; Reasonable? You're trying to stack-allocate 2.5MB of data. Don't do that -- stack sizes are 2MB or less in most operating systems. Besides, doing anything useful with a buffer that size would completely drown out the overhead of calling malloc. Ryan -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple