DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D0F593857C6F
Message-ID: <fa647f83-c5ed-6dea-fcba-c8b799abe12f@gmail.com>
Date: Thu, 18 Nov 2021 16:11:06 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.3.1
Subject: Re: possible snprintf() regression in 3.3.2
Content-Language: en-GB
To: cygwin@cygwin.com
References: <20211117003718.GF10332@venus.tony.develop-help.com>
 <20211117182108.b38599f5e13071bf269a0d48@nifty.ne.jp>
 <YZT1S8wDnaBuYf5u@calimero.vinschen.de>
 <20211118000649.GG10332@venus.tony.develop-help.com>
 <20211118203538.a049809d57731fe375801c15@nifty.ne.jp>
 <YZZSzPhbqF6cQAiu@calimero.vinschen.de>
In-Reply-To: <YZZSzPhbqF6cQAiu@calimero.vinschen.de>
From: Noel Grandin via Cygwin <cygwin@cygwin.com>
Reply-To: Noel Grandin <noelgrandin@gmail.com>
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie.com@cygwin.com>


On 2021/11/18 3:19 pm, Corinna Vinschen via Cygwin wrote:
> My patch raised NDEC from 43 to 1023 to allow aproximately the same
> number of digits as glibc.  Newlib strives to support embedded targets
> and bare metal.  Some of them are lucky if they have a stack size of 1K.
> The outbuf buffer is created on the stack, so I used ndigits to save
> stack space.
> 
> While that patch fixes the reported problem, it will make users of
> smaller-than-Cygwin targets pretty unhappy.
> 
> A workaround would be to malloc outbuf instead.  Given that printf

printf is often performance sensitive, and using malloc there would likely be significantly slower.

Possibly use alloca() to allocate only the necessary amount on stack?
Seems unlikely that embedded systems would be printing values that needed such large space anyway.

-- 
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