X-Recipient: archive-cygwin@delorie.com X-Original-To: cygwin@cygwin.com Delivered-To: cygwin@cygwin.com DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 7836E385840D Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=develop-help.com Authentication-Results: sourceware.org; spf=none smtp.mailfrom=develop-help.com Date: Sun, 21 Nov 2021 11:16:13 +1100 From: Tony Cook To: Sam Edge Subject: Re: possible snprintf() regression in 3.3.2 Message-ID: <20211121001613.GH10332@venus.tony.develop-help.com> References: <20211117003718.GF10332@venus.tony.develop-help.com> <20211117182108.b38599f5e13071bf269a0d48@nifty.ne.jp> <20211118000649.GG10332@venus.tony.develop-help.com> <20211118203538.a049809d57731fe375801c15@nifty.ne.jp> <7545bb24-43de-cd7d-0764-55c85f1af957@gmx.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <7545bb24-43de-cd7d-0764-55c85f1af957@gmx.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Spam-Status: No, score=0.7 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, KAM_NUMSUBJECT, KHOP_HELO_FCRDNS, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=no autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: cygwin@cygwin.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: cygwin-bounces+archive-cygwin=delorie.com@cygwin.com Sender: "Cygwin" On Thu, Nov 18, 2021 at 09:08:40PM +0000, Sam Edge via Cygwin wrote: > I use newlib on embedded with threading libs that have predetermined > fixed thread stack sizes. While we tend to have more RAM than in former > times we also have multiple thread stacks. Use of alloca() or variable > length automatic arrays makes me wince especially in code I might not be > able to avoid calling which is often the case with XXXprintf() in > third-party libraries' debug output. I'd usually rather take the > performance hit from using heap instead of having to make all my stacks > bigger. A simple option would be to use an small auto fixed buffer for most conversions, but use malloc() for %f formats for numbers greater in magnitude than some limit, though it would also need to be adjusted for the precision (ndigits here), since they take extra space. This would avoid using the optional-to-implement VLA feature too. Tony -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple