From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id D175749207 for ; Mon, 5 Feb 2024 20:21:05 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 7FD9968D131; Mon, 5 Feb 2024 22:21:02 +0200 (EET) Received: from w4.tutanota.de (w4.tutanota.de [81.3.6.165]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 0A1AC68CE33 for ; Mon, 5 Feb 2024 22:20:56 +0200 (EET) Received: from tutadb.w10.tutanota.de (unknown [192.168.1.10]) by w4.tutanota.de (Postfix) with ESMTP id 840201060136 for ; Mon, 5 Feb 2024 20:20:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1707164455; s=s1; d=lynne.ee; h=From:From:To:To:Subject:Subject:Content-Description:Content-ID:Content-Type:Content-Type:Content-Transfer-Encoding:Content-Transfer-Encoding:Cc:Date:Date:In-Reply-To:In-Reply-To:MIME-Version:MIME-Version:Message-ID:Message-ID:Reply-To:References:References:Sender; bh=a7C+BDqLj/R35dZBwR8NT3wu/de8edmCjUkkxqbJ7ds=; b=OaoVl6S5B8pIqgFRzpEbpL+hBJxBEWejhYn180i+VV4bJKejlvyq2aB1aTZL+Gu2 X4sn5WeO7xdRe5sbCsJKE6N0A0FcAlbG2OnB7ZtwT8w+yNt/VyKlTXQE87VGNeGy1Qs ho8+Hs6PtQn0ivgqDJO3e4sL+gSQ5WXzzd8Nd5Nyu92B/Mcdk93r/s/fX4AG+0lI4zE +M56N6aa3Tx9AMz+jPgwCZWGoKpGG3LVuk+mgbUFv49Ra5JSL/A+SNu8P1sqN1FgV67 DxQo4UIbQJQOcGCmzTFn083vOdH12YhUKhtoHx3DqiGtjHbkN8IiOH9emdfdKv06Pdn 30BhAuTi6w== Date: Mon, 5 Feb 2024 21:20:55 +0100 (CET) From: Lynne To: FFmpeg development discussions and patches Message-ID: In-Reply-To: <20240205195802.14522-2-anton@khirnov.net> References: <20240205195802.14522-1-anton@khirnov.net> <20240205195802.14522-2-anton@khirnov.net> MIME-Version: 1.0 Subject: Re: [FFmpeg-devel] [PATCH 2/2] Require compilers to support C17. X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: Feb 5, 2024, 20:59 by anton@khirnov.net: > It should be available in all relevant modern compilers and will allow > us to use features like anonymous unions. > > Note that stdatomic.h is still emulated on MSVC, as current versions > require the /experimental:c11atomics, and do not support > ATOMIC_VAR_INIT() anyway. > --- > Now moving to C17 rather than C11, as the former contains important > fixes and its support across the compilers we care about should be > similar. > > Now also tested with MSVC in wine, thanks to Martin for pointing me at > https://github.com/mstorsjo/msvc-wine > --- > configure | 23 +++++++++++------------ > doc/developer.texi | 10 ++-------- > 2 files changed, 13 insertions(+), 20 deletions(-) > > diff --git a/configure b/configure > index f72533b7d2..1bb9e23f19 100755 > --- a/configure > +++ b/configure > @@ -4705,7 +4705,7 @@ msvc_common_flags(){ > # generic catch all at the bottom will print the original flag. > -Wall) ;; > -Wextra) ;; > - -std=c*) ;; > + -std=c*) echo /std:${flag#-std=};; > # Common flags > -fomit-frame-pointer) ;; > -g) echo -Z7 ;; > @@ -4750,7 +4750,7 @@ icl_flags(){ > # Despite what Intel's documentation says -Wall, which is supported > # on Windows, does enable remarks so disable them here. > -Wall) echo $flag -Qdiag-disable:remark ;; > - -std=c99) echo -Qstd=c99 ;; > + -std=c17) echo -Qstd=c17 ;; > -flto*) echo -ipo ;; > esac > done > @@ -4798,7 +4798,7 @@ suncc_flags(){ > athlon*) echo -xarch=pentium_proa ;; > esac > ;; > - -std=c99) echo -xc99 ;; > + -std=c17) echo -xc17 ;; > -fomit-frame-pointer) echo -xregs=frameptr ;; > -fPIC) echo -KPIC -xcode=pic32 ;; > -W*,*) echo $flag ;; > @@ -4887,8 +4887,8 @@ probe_cc(){ > _type=suncc > _ident=$($_cc -V 2>&1 | head -n1 | cut -d' ' -f 2-) > _DEPCMD='$(DEP$(1)) $(DEP$(1)FLAGS) $($(1)DEP_FLAGS) $< | sed -e "1s,^.*: ,$@: ," -e "\$$!s,\$$, \\\," -e "1!s,^.*: , ," > $(@:.o=.d)' > - _DEPFLAGS='-xM1 -xc99' > - _ldflags='-std=c99' > + _DEPFLAGS='-xM1 -xc17' > + _ldflags='-std=c17' > _cflags_speed='-O5' > _cflags_size='-O5 -xspace' > _flags_filter=suncc_flags > @@ -5517,21 +5517,20 @@ if test "$?" != 0; then > die "C compiler test failed." > fi > > -add_cppflags -D_ISOC99_SOURCE > +add_cppflags -D_ISOC11_SOURCE > add_cxxflags -D__STDC_CONSTANT_MACROS > check_cxxflags -std=c++11 || check_cxxflags -std=c++0x > > -# some compilers silently accept -std=c11, so we also need to check that the > +# some compilers silently accept -std=c17, so we also need to check that the > # version macro is defined properly > -test_cflags_cc -std=c11 ctype.h "__STDC_VERSION__ >= 201112L" && > - add_cflags -std=c11 || > - check_cflags -std=c99 > +test_cflags_cc -std=c17 ctype.h "__STDC_VERSION__ >= 201710L" && > + add_cflags -std=c17 || die "Compiler lacks C17 support" > > check_cppflags -D_FILE_OFFSET_BITS=64 > check_cppflags -D_LARGEFILE_SOURCE > > -add_host_cppflags -D_ISOC99_SOURCE > -check_host_cflags -std=c99 > +add_host_cppflags -D_ISOC11_SOURCE > +check_host_cflags -std=c17 > check_host_cflags -Wall > check_host_cflags $host_cflags_speed > > diff --git a/doc/developer.texi b/doc/developer.texi > index eed0ee4915..6e9807aa06 100644 > --- a/doc/developer.texi > +++ b/doc/developer.texi > @@ -56,14 +56,8 @@ and should try to fix issues their commit causes. > > @section Language > > -FFmpeg is mainly programmed in the ISO C99 language, extended with: > -@itemize @bullet > -@item > -Atomic operations from C11 @file{stdatomic.h}. They are emulated on > -architectures/compilers that do not support them, so all FFmpeg-internal code > -may use atomics without any extra checks. However, @file{stdatomic.h} must not > -be included in public headers, so they stay C99-compatible. > -@end itemize > +FFmpeg is mainly programmed in the ISO C17 language, except for the public > +headers which must stay C99 compatible. > > Compiler-specific extensions may be used with good reason, but must not be > depended on, i.e. the code must still compile and work with compilers lacking > Looks good to me. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".