X-Recipient: archive-cygwin@delorie.com X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00,SPF_PASS X-Spam-Check-By: sourceware.org Message-ID: <4AB0BE8A.6060707@gmail.com> Date: Wed, 16 Sep 2009 11:31:38 +0100 From: Dave Korn User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: cygwin@cygwin.com Subject: Re: Cygwin 1.7/1.5 C99 conformance (GCC, libc) References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Matthias Andree wrote: > Now, Cygwin 1.5 and 1.7 appear to lack long double library support in > libc/libm -- which is required for a hosted C99 implementation however, > but not for a freestanding C99 implementation. > > Trying to solve this, I found another Cygwin issue: GCC 3.4.4 sets > __STDC_HOSTED__ to 1 by default (that's a GCC factory default). Just FTR, Cygwin-1.5 and gcc-3.4.4 are end-of-life and will never be updated again. > I propose that this gets overridden to 0 in Cygwin-ported GCC compilers > until the library support for a C99-conforming full hosted > implementation is in place, so that applications can safely check Sorry, I don't think that's a good idea. There are a whole world of other differences implied by the freestanding-vs-hosted distinction that I think it would not be wise for the compiler to lie about. It is indeed unfortunate that our C library support (which derives from newlib) is incomplete, and this gap between theory and practice is what autoconf was invented to bridge. (Autoconf is of course a compromise born of necessity which in an ideal world wouldn't exist. But at least it means these problems can be dealt with in a practical and systematic fashion.) It mightn't be too hard to get long double support into newlib, but it's all a matter of someone having the time and wherewithal to actually do it. cheers, DaveK -- 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