From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.3 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 28211 invoked from network); 16 Apr 2021 18:51:34 -0000 Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with ESMTPUTF8; 16 Apr 2021 18:51:34 -0000 Received: (qmail 23843 invoked by uid 550); 16 Apr 2021 18:51:31 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 23825 invoked from network); 16 Apr 2021 18:51:30 -0000 Date: Fri, 16 Apr 2021 14:51:18 -0400 From: Rich Felker To: =?utf-8?B?w4lyaWNv?= Nogueira Cc: musl@lists.openwall.com Message-ID: <20210416185118.GP2546@brightrain.aerifal.cx> References: <20210416003521.2147-1-ericonr@disroot.org> <20210416003521.2147-2-ericonr@disroot.org> <20210416142658.GO2546@brightrain.aerifal.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Subject: Re: [musl] [PATCH 2/2] include in On Fri, Apr 16, 2021 at 02:57:21PM -0300, Érico Nogueira wrote: > Em 16/04/2021 11:26, Rich Felker escreveu: > >On Thu, Apr 15, 2021 at 09:35:21PM -0300, Érico Nogueira wrote: > >>GCC source code does contain a function to pre-include the > >> header for glibc targets, but even so glibc still > > I seem to have been mistaken about the feature being glibc specific; using > > echo "" | cc -xc - -E > > it seems the file does end up being included automatically. > > However, when using clang instead of gcc, it isn't included > automatically. I don't know if this is something that clang ought to > fix, is there some sort of standard about ? Michael > Forney's cproc compiler doesn't seem to touch it either. It's not a standard, but given that it's established I don't see any reasonable argument for other compilers not to just do the same. You can always fix them manually with CC="clang -include stdc-predef.h" or similar though. > >>includes it in their own header. furthermore, even if GCC > >>implemented this for musl targets, it is still necessary for other > >>compilers or previous versions of GCC. > >>--- > >> include/features.h | 2 ++ > >> 1 file changed, 2 insertions(+) > >> > >>diff --git a/include/features.h b/include/features.h > >>index 85cfb72a..f3d53cbe 100644 > >>--- a/include/features.h > >>+++ b/include/features.h > >>@@ -1,6 +1,8 @@ > >> #ifndef _FEATURES_H > >> #define _FEATURES_H > >>+#include > >>+ > >> #if defined(_ALL_SOURCE) && !defined(_GNU_SOURCE) > >> #define _GNU_SOURCE 1 > >> #endif > >>-- > >>2.31.1 > > > >I've hesitated to do this because features.h is not consistently > >included from all standard headers (only if it's needed), and the > >result would be inconsistent exposure of these macros. (Also > >inconsistent if they're checked before any standard headers are > >included, which is unfixable.) I think it makes more sense to just add > >"-include stdc-predef.h" to the compiler specfile or equivalent if it > >doesn't auto-include it, so that you get behavior that actually > >matches the spec. > > Do you know if clang can use the specfile? That would make it worth > it adding the entry, since GCC has the expected behavior already. No; specfiles are highly tied to GCC's compiler driver architecture. clang might have some other equivalent mechanism though. Rich