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Keith Thompson <Keith.S.Thompson+u@gmail.com> writes: > James Kuyper <jameskuyper@alumni.caltech.edu> writes: > >> On 2025-08-05 17:13, Kaz Kylheku wrote: >> >>> On 2025-08-04, Michael S <already5chosen@yahoo.com> wrote: >>> >>>> On Mon, 4 Aug 2025 15:25:54 -0400 >>>> James Kuyper <jameskuyper@alumni.caltech.edu> wrote: >> >> ... >> >>>>> If _BitInt is accepted by older versions of gcc, that means it >>>>> was supported as a fully-conforming extension to C. Allowing >>>>> implementations to support extensions in a fully-conforming >>>>> manner is one of the main purposes for which the standard >>>>> reserves identifiers. If you thought that gcc was too >>>>> conservative to support extensions, you must be thinking of the >>>>> wrong organization. >>>> >>>> I know that gcc supports extensions. >>>> I also know that gcc didn't support *this particular extension* >>>> up until quite recently. >>> >>> I think what James means is that GCC supports, as an extension, >>> the use of any _[A-Z].* identifier whatsoever that it has not >>> claimed for its purposes. >> >> No, I meant very specifically that if, as reported, _BitInt was >> supported even in earlier versions, then it was supported as an >> extension. > > gcc 13.4.0 does not recognize _BitInt at all. > > gcc 14.2.0 handles _BitInt as a language feature in C23 mode, > and as an "extension" in pre-C23 modes. > > It warns about _BitInt with "-std=c17 -pedantic", but not with > just "-std=c17". I think I would have preferred a warning with > "-std=c17", but it doesn't bother me. There's no mention of _BitInt > as an extension or feature in the documentation. An implementation > is required to document the implementation-defined value of > BITINT_MAXWIDTH, so that's a conformance issue. In pre-C23 mode, > since it's not documented, support for _BitInt is not formally an > "extension"; it's an allowed behavior in the presence of code that > has undefined behavior due to its use of a reserved identifier. > (This is a picky language-lawyerly interpretation.) To clarify the last part, undefined behavior is allowed only because a diagnostic was generated. If there were no diagnostic then it would have to be documented as an extension, otherwise the implementation would not be conforming.
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Re: VAX Michael S <already5chosen@yahoo.com> - 2025-08-04 18:28 +0300
Re: VAX Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-08-04 09:53 -0700
Re: VAX Michael S <already5chosen@yahoo.com> - 2025-08-04 22:03 +0300
Re: VAX James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-08-04 15:25 -0400
Re: VAX Michael S <already5chosen@yahoo.com> - 2025-08-04 22:40 +0300
Re: VAX "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2025-08-04 12:44 -0700
Re: VAX Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-08-04 22:21 -0700
Re: VAX Kaz Kylheku <643-408-1753@kylheku.com> - 2025-08-05 21:25 +0000
Re: VAX Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-08-05 19:14 -0700
Re: VAX Kaz Kylheku <643-408-1753@kylheku.com> - 2025-08-06 04:31 +0000
Re: VAX Michael S <already5chosen@yahoo.com> - 2025-08-06 11:48 +0300
Re: VAX James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-08-06 11:56 -0400
Re: VAX Tim Rentsch <tr.17687@z991.linuxsc.com> - 2025-12-15 11:51 -0800
Re: VAX Kaz Kylheku <643-408-1753@kylheku.com> - 2025-08-05 21:13 +0000
Re: VAX James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-08-06 11:54 -0400
Re: VAX Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-08-06 13:58 -0700
Re: VAX Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-01-06 21:33 -0800
Re: VAX Kaz Kylheku <643-408-1753@kylheku.com> - 2025-08-05 21:08 +0000
Re: VAX Jakob Bohm <egenagwemdimtapsar@jbohm.dk> - 2025-08-17 20:18 +0200
Re: VAX Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-08-17 22:18 -0700
Re: VAX Richard Heathfield <rjh@cpax.org.uk> - 2025-08-18 08:02 +0100
Re: VAX David Brown <david.brown@hesbynett.no> - 2025-08-18 11:34 +0200
Re: VAX Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-08-18 21:57 -0700
Re: VAX Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-01-06 21:14 -0800
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