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=-10.9 required=5.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HTML_MESSAGE,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 19623 invoked from network); 16 Apr 2021 22:13:35 -0000 Received: from mother.openwall.net (195.42.179.200) by inbox.vuxu.org with ESMTPUTF8; 16 Apr 2021 22:13:35 -0000 Received: (qmail 19712 invoked by uid 550); 16 Apr 2021 22:13:31 -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 19694 invoked from network); 16 Apr 2021 22:13:31 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=JarlYgZ0oADjJ2mW2mWQ0d2gsS6FavBRienNooxXF6c=; b=qCJ0ecqED/jqGscDTPI9JGOTdKxrkLQkUCJ7DnTcYT9iBnNES9f6Y1E4FqfM2z6JjH om7DD2B8/0QrQuCNUGDCV5Wl3znTVixoKJm54vzePJLAu5hfWaS73tXFQRWpKXefrvnE JmQVx8jF7GqVzFJdkkKn2b4y3nII/pExf0souo/IoHZbJanuiXdSIKC08KVjxEJBo3Hd 67EAjW36I92+ttRRBMOdE1/7yY2PZCjmV7sjm0F2W39BFoYXNyAqTTuo2lIElmcwQnAr OMMZRvhdGFXMRPGIwkD0/UU+kD/5yRKicyavvsg3dgS78kqzJgfRR2LFp0P+dGzvOqqY k7hw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=JarlYgZ0oADjJ2mW2mWQ0d2gsS6FavBRienNooxXF6c=; b=Jl8wKtvOdXQCnlVwVFO96a1c8xAWlgigVARWItmTtAID60q2UO04GD499zmhfb8BBm WrvVOMbMEnGnNS+or/BYomJS6lN6GZVo7ennD+FNH5TdZHYmTXNPXd4y72t92poOXdOL S2Lq8YX5MeU5aUJnb/NKREpd6vKpeRF5/81b6A195H7KPP5LZzKhdELXjgG0UOFJ6VDS RuIdInEpeyNPxfbxHdDQ5cL4maG6Qge5MsAk2jWdo0pB8DOJHBQHPiLBwGk3LBoPm4Or VjZAwUv6OYpgNSJ17Oqn71PEJQTgb93ZcQF4F5VXzyOxelfFY0UkUxJSp39Mywu8ctGB NoEw== X-Gm-Message-State: AOAM531ER2G17NSnk7CkV5XENWG4aMTqpeyWHVwKAornqXBzPZpkSb/d 2iV1Emn9ypRJ9rig3BBsROM1e2qvw2qnH2BE6Zo2GqgPdr8glg== X-Google-Smtp-Source: ABdhPJz03MtKtcIX5oA7A4/RR4+MzlmOLKCbjkLbRQ5ZqosdjFh7242bG2pPMAXGDkat77TNOnUBZJ+shAQK0cvqjzw= X-Received: by 2002:a19:7e87:: with SMTP id z129mr4177366lfc.624.1618611199431; Fri, 16 Apr 2021 15:13:19 -0700 (PDT) MIME-Version: 1.0 References: <20210416003521.2147-1-ericonr@disroot.org> <20210416003521.2147-2-ericonr@disroot.org> <20210416142658.GO2546@brightrain.aerifal.cx> <20210416185118.GP2546@brightrain.aerifal.cx> In-Reply-To: <20210416185118.GP2546@brightrain.aerifal.cx> From: James Y Knight Date: Fri, 16 Apr 2021 18:12:52 -0400 Message-ID: To: musl@lists.openwall.com Cc: =?UTF-8?Q?=C3=89rico_Nogueira?= Content-Type: multipart/alternative; boundary="00000000000092c16c05c01e4994" Subject: Re: [musl] [PATCH 2/2] include in --00000000000092c16c05c01e4994 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Ugh, I thought Clang had added support for this years ago. But it looks like the change (https://reviews.llvm.org/D34158) never actually made it in; it ran into some test failures after being committed and was reverted, and then never reapplied. :( On Fri, Apr 16, 2021 at 2:51 PM Rich Felker wrote: > On Fri, Apr 16, 2021 at 02:57:21PM -0300, =C3=89rico Nogueira wrote: > > Em 16/04/2021 11:26, Rich Felker escreveu: > > >On Thu, Apr 15, 2021 at 09:35:21PM -0300, =C3=89rico 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=3D"clang -include stdc-predef.h" or > similar though. > > > >>includes it in their own header. furthermore, even if GC= C > > >>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 > --00000000000092c16c05c01e4994 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Ugh, I thought Clang had added support for this years ago.= But it looks like the change (= https://reviews.llvm.org/D34158) never actually made it in; it ran=C2= =A0into some test=C2=A0failures after being committed and was reverted,=C2= =A0and then never reapplied. :(


On Fri, Apr 16, 2021 at 2:51 = PM Rich Felker <dal= ias@libc.org> wrote:
On Fri, Apr 16, 2021 at 02:57:21PM -0300, =C3=89rico Nogueira w= rote:
> Em 16/04/2021 11:26, Rich Felker escreveu:
> >On Thu, Apr 15, 2021 at 09:35:21PM -0300, =C3=89rico Nogueira wrot= e:
> >>GCC source code does contain a function to pre-include the
> >><stdc-predef.h> header for glibc targets, but even so gl= ibc still
>
> I seem to have been mistaken about the feature being glibc specific; u= sing
>
>=C2=A0 =C2=A0 =C2=A0echo "" | 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 <stdc-predef.h>? Micha= el
> 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 se= e any
reasonable argument for other compilers not to just do the same. You
can always fix them manually with CC=3D"clang -include stdc-predef.h&q= uot; or
similar though.

> >>includes it in their own <features.h> header. furthermor= e, even if GCC
> >>implemented this for musl targets, it is still necessary for o= ther
> >>compilers or previous versions of GCC.
> >>---
> >>=C2=A0 include/features.h | 2 ++
> >>=C2=A0 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 @@
> >>=C2=A0 #ifndef _FEATURES_H
> >>=C2=A0 #define _FEATURES_H
> >>+#include <stdc-predef.h>
> >>+
> >>=C2=A0 #if defined(_ALL_SOURCE) && !defined(_GNU_SOURC= E)
> >>=C2=A0 #define _GNU_SOURCE 1
> >>=C2=A0 #endif
> >>--
> >>2.31.1
> >
> >I've hesitated to do this because features.h is not consistent= ly
> >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 ar= e
> >included, which is unfixable.) I think it makes more sense to just= add
> >"-include stdc-predef.h" to the compiler specfile or equ= ivalent if it
> >doesn't auto-include it, so that you get behavior that actuall= y
> >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
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