Date: Fri, 14 Sep 2007 13:40:06 GMT From: Rhialto <rhialto@falu.nl> To: freebsd-standards@FreeBSD.org Subject: Re: standards/116346: FreeBSD has no conforming C implementation Message-ID: <200709141340.l8EDe6BN089882@freefall.freebsd.org>
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The following reply was made to PR standards/116346; it has been noted by GNATS. From: Rhialto <rhialto@falu.nl> To: Erik Trulsson <ertr1013@student.uu.se> Cc: freebsd-gnats-submit@FreeBSD.org Subject: Re: standards/116346: FreeBSD has no conforming C implementation Date: Fri, 14 Sep 2007 15:35:06 +0200 On Fri 14 Sep 2007 at 14:44:50 +0200, Erik Trulsson wrote: > Yes, it does. You do however have to invoke the C compiler in > standard-conforming mode. > By default gcc (like most C compilers) is not in standards-conforming mode. > > Try invoking it as 'gcc -ansi' or 'c89' to get a C compiler conforming to > the 1989 ANSI C standard. (Invoking it as 'c99' or as 'gcc -std=c99' should > get a C99 compiler, although I believe support for the 1999 C standard is > not quite complete.) Of course no makefile project ever does that at all, in practice, yet they still expect to have the promised namespace available for their own identifiers. I was made aware of this problem when some project was using the "unix" preprocessor definition as a feature test, and it failed to build on a different BSD system, which IMHO is more correct in this regard. I don't know where to look this up in POSIX and related standards, but I don't expect that any of them actually *requires* a pre-#defined unix, since they most likely don't want to contradict the C standard. If they would mention any such feature test at all, they would require #inclusion of some specific header first, or use a name which is reserved to the implementation, such as __unix__. Otherwise, by your reasoning, the default-invoked compiler could do anything, and you would not need to bother having all those __-prefixed names in /usr/include/sys/*. Therefore, there is no standards-related reason for having "unix" and I still argue for removing it. -Olaf. -- ___ Olaf 'Rhialto' Seibert -- You author it, and I'll reader it. \X/ rhialto/at/xs4all.nl -- Cetero censeo "authored" delendum esse.
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