Date: Fri, 4 Sep 2009 09:16:29 +0400 From: Andrey Chernov <ache@nagual.pp.ru> To: Bruce Evans <brde@optusnet.com.au> Cc: svn-src-head@freebsd.org, Dag-Erling Sm??rgrav <des@des.no>, svn-src-all@freebsd.org, src-committers@freebsd.org, "Simon L. Nielsen" <simon@freebsd.org> Subject: Re: svn commit: r196752 - head/lib/libc/stdtime Message-ID: <20090904051629.GA88503@nagual.pp.ru> In-Reply-To: <20090904115255.Q48987@delplex.bde.org> References: <200909020456.n824uUqQ082136@svn.freebsd.org> <20090902070808.GA1290@arthur.nitro.dk> <20090902084002.GA17325@nagual.pp.ru> <867hwgcwvo.fsf@ds4.des.no> <20090903084325.GA65192@nagual.pp.ru> <86zl9c9z05.fsf@ds4.des.no> <20090904115255.Q48987@delplex.bde.org>
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On Fri, Sep 04, 2009 at 01:42:04PM +1000, Bruce Evans wrote: > The patch is missing the corresponding text for wctype functions > (argmuments of type wint_t generally give undefined behaviour unless > their value is representable as a wchar_t or equal to the value of > WEOF). In FreeBSD, wint_t has the same type as wchar_t and that type > is int, so bugs in this area are latent (unportable code might run > on FreeBSD, and there might be problems with the sign bit and/or with > WEOF being indistinguishable from a valid wide char encoding. Yes, having the same note for wctype family will be nice too. > It should be something like "if the value to be > passed is represented as a signed char" ... I don't know a good easy > way to fix "must be cast ... to avoid sign-extension errors". The > value must be converted to one representable as an unsigned char to > work, but that is not always possible, and blindly casting may give > a wrong value. > Exotic machines include: I think, "exotic machines" examples you mention already brokes too many other aspects regarding to char manipulating, so nobody will really make such machines with standard-compliance C compiler on them :) > Sign extension for passing a signed char is not an error. The error is > passing a negative value. Yes. Perhaps 'Never pass negative arg there, including sign-extended char' or something alike. > Neither C99 nor POSIX gives any advice. They just say that the behaviour > is undefined if the value is not representable as an unsigned char or > equal to the value of EOF. Yes, I already mention that. > % Index: lib/libc/locale/isrune.3 > % Index: lib/libc/locale/digittoint.3 > % Index: lib/libc/locale/isascii.3 > % Index: lib/libc/locale/toascii.3 Yes, those ones works with int. I don't pay attention to them in the whole patch :( About other wording nuances mentioned in your reply, I don't have an opinion, everybody knows my English is poor :) -- http://ache.pp.ru/
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