From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/10024 Path: news.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: Deduplicating __NR_* and SYS_* syscall defines Date: Wed, 11 May 2016 17:53:12 -0400 Message-ID: <20160511215311.GI21636@brightrain.aerifal.cx> References: <20160510002637.GA21262@dora.lan> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1463003617 5763 80.91.229.3 (11 May 2016 21:53:37 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 11 May 2016 21:53:37 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-10037-gllmg-musl=m.gmane.org@lists.openwall.com Wed May 11 23:53:30 2016 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1b0c4O-0003RP-Np for gllmg-musl@m.gmane.org; Wed, 11 May 2016 23:53:28 +0200 Original-Received: (qmail 7308 invoked by uid 550); 11 May 2016 21:53:26 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 7282 invoked from network); 11 May 2016 21:53:25 -0000 Content-Disposition: inline In-Reply-To: <20160510002637.GA21262@dora.lan> User-Agent: Mutt/1.5.21 (2010-09-15) Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:10024 Archived-At: On Mon, May 09, 2016 at 07:26:37PM -0500, Bobby Bingham wrote: > During the powerpc64 review, Rich mentioned wanting to replace the > arch/*/bits/syscall.h files with .in files that would be preprocessed with > something like: > > sed -e p -e s/__NR_/SYS_/ < $< > $@ > > This would eliminate a lot of intra-file duplication here. > > I took a look, and this won't quite work as-is, because the following > lines in the arm version would end up outputting duplicate definitions: > > #define __ARM_NR_breakpoint 0x0f0001 > #define __ARM_NR_cacheflush 0x0f0002 > #define __ARM_NR_usr26 0x0f0003 > #define __ARM_NR_usr32 0x0f0004 > #define __ARM_NR_set_tls 0x0f0005 This is easily fixed by something like: sed -e /__NR_/p -e s/__NR_/SYS_/ < $< > $@ > Same thing for this line in x32: > > #define __X32_SYSCALL_BIT 0x40000000 In general we've tried to eliminate this sort of macro and direct-code the values. I would be in favor of doing the same for x32 I think. But with my fixed sed command (above) I think that change is unnecssary and orthogonal to the deduplication. > I'm thinking something like the following awk script would work: > > { > print > } > > $1 ~ /^#(define|undef)$/ && $2 ~ /^__NR_/ { > sub(/__NR_/, "SYS_", $2) > print > } > > The handling for #undef is for the x32 file. It looks like only the > `#undef __NR_getdents' in that file is actually necessary, and even that > could be avoided by just omitting the earlier line: > > #define __NR_getdents (__X32_SYSCALL_BIT + 78) I don't see why any #undef is needed here; this looks like leftover cruft that was not properly cleaned up. All the logic for replacing syscall numbers belongs in src/internal/syscall.h or arch/$ARCH/syscall_arch.h, I think. > So maybe we can get rid of the #undefs there, and simplify the awk script > accordingly. > > Thoughts on this approach? If this sounds ok, I'll submit a patch. I'd rather use sed than awk if possible since it's more universally available and understood. Rich