Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752674Ab2EWFWj (ORCPT ); Wed, 23 May 2012 01:22:39 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:51215 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751559Ab2EWFWg (ORCPT ); Wed, 23 May 2012 01:22:36 -0400 Date: Wed, 23 May 2012 01:22:36 -0400 From: Kent Overstreet To: Joe Perches Cc: Tejun Heo , linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, agk@redhat.com Subject: Re: [PATCH] Add human-readable units modifier to vsnprintf() Message-ID: <20120523052236.GA14312@dhcp-172-18-216-138.mtv.corp.google.com> References: <20120522211706.GH14339@google.com> <20120523031214.GA607@dhcp-172-18-216-138.mtv.corp.google.com> <1337744190.13111.33.camel@joe2Laptop> <20120523045023.GE607@dhcp-172-18-216-138.mtv.corp.google.com> <1337749848.13111.40.camel@joe2Laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1337749848.13111.40.camel@joe2Laptop> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1470 Lines: 48 On Tue, May 22, 2012 at 10:10:48PM -0700, Joe Perches wrote: > On Wed, 2012-05-23 at 00:50 -0400, Kent Overstreet wrote: > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > [] > > @@ -1002,6 +1023,7 @@ int format_decode(const char *fmt, struct printf_spec *spec) > > case ' ': spec->flags |= SPACE; break; > > case '#': spec->flags |= SPECIAL; break; > > case '0': spec->flags |= ZEROPAD; break; > > + case 'h': spec->flags |= HUNITS; break; > > default: found = false; > > } > > > > I think that doesn't work well because > gcc __attribute__((format(printf, x, y))) > verification fails. Yeah, I already ran into that. I was looking through the gcc docs to see if there was a way to add modifiers (how is it done for the other kernel specific format strings?) but I haven't found anything yet > It's also possible > to confuse it with printf's own 'h' / > integer precision use. Well, that's annoying. Any suggestions? > > $ cat h.c > #include > #include > > int main(int argc, char** argv) > { > printf("%h02u\n", 1); > return 0; > } > > $ gcc h.c > h.c: In function ‘main’: > h.c:6:3: warning: unknown conversion type character ‘0’ in format [-Wformat] > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/