From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [PATCH] checkpatch: re-enable warnings about split long strings Date: Thu, 28 Mar 2019 19:03:10 +0000 Message-ID: References: <20170929153749.9806-1-stephen@networkplumber.org> <20171002115317.GJ3871@6wind.com> <20171002134624.GA10500@bricha3-MOBL3.ger.corp.intel.com> <20171002162106.GQ3871@6wind.com> <20171003103813.GA20140@bricha3-MOBL3.ger.corp.intel.com> <20171003105612.GS3871@6wind.com> <92660560-a08f-662c-293c-91d1a988e5f3@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Stephen Hemminger , Bruce Richardson , Luca Boccassi , Thomas Monjalon , dpdk-dev To: Adrien Mazarguil Return-path: Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by dpdk.org (Postfix) with ESMTP id 948EE2D13 for ; Thu, 28 Mar 2019 20:03:13 +0100 (CET) In-Reply-To: <92660560-a08f-662c-293c-91d1a988e5f3@intel.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 3/28/2019 7:02 PM, Ferruh Yigit wrote: > On 10/3/2017 11:56 AM, adrien.mazarguil at 6wind.com (Adrien Mazarguil) wrote: >> On Tue, Oct 03, 2017 at 11:38:13AM +0100, Bruce Richardson wrote: >>> On Mon, Oct 02, 2017 at 06:21:06PM +0200, Adrien Mazarguil wrote: >>>> On Mon, Oct 02, 2017 at 02:46:24PM +0100, Bruce Richardson wrote: >>>>> On Mon, Oct 02, 2017 at 01:53:17PM +0200, Adrien Mazarguil wrote: >>>>>> Hi Stephen, >>>>>> >>>>>> On Fri, Sep 29, 2017 at 08:37:49AM -0700, Stephen Hemminger wrote: >>>>>>> The Linux kernel style policy about strings is that strings should >>>>>>> be always put on one line. This makes sense since a typical use case >>>>>>> is for a user to type the error message into a search engine or >>>>>>> grep, and it won't be found if split across lines. This patch just >>>>>>> re-enables that check. >>>>>>> >>>>>>> Yes, lots of DPDK code now splits strings, that doesn't make it >>>>>>> right. >>>>>>> >>>>>>> Signed-off-by: Stephen Hemminger --- >>>>>>> devtools/checkpatches.sh | 1 - 1 file changed, 1 deletion(-) >>>>>>> >>>>>>> diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh >>>>>>> index a56c41a301c0..3e6081dd673e 100755 --- >>>>>>> a/devtools/checkpatches.sh +++ b/devtools/checkpatches.sh @@ -44,7 >>>>>>> +44,6 @@ options="$options --show-types" options="$options >>>>>>> --ignore=LINUX_VERSION_CODE,FILE_PATH_CHANGES,\ >>>>>>> VOLATILE,PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\ >>>>>>> PREFER_KERNEL_TYPES,BIT_MACRO,CONST_STRUCT,\ >>>>>>> -SPLIT_STRING,LONG_LINE_STRING,\ >>>>>>> LINE_SPACING,PARENTHESIS_ALIGNMENT,NETWORKING_BLOCK_COMMENT_STYLE,\ >>>>>>> NEW_TYPEDEFS,COMPARISON_TO_NULL" >>>>>> >>>>>> I'm not sure, given that the main reason for splitting strings in the >>>>>> first place is to avoid LONG_LINE_STRING warnings, I think we must >>>>>> choose between the two options. If split strings are not allowed, then >>>>>> long lines must be. >>>>>> >>>>>> Since checkpatches.sh is used by various automated scripts to complain >>>>>> loudly about problems in submissions, the above change prevents >>>>>> maintainers from writing long string at all (can't split and can't go >>>>>> past 80 columns). >>>>>> >>>>>> As a result, they will be tempted to cripple their code with nasty >>>>>> workarounds to shut up checkpatches.sh, we don't want that to happen. >>>>>> >>>>>> Also I think the reasons stated by original commit cf75514c8e2e are >>>>>> still relevant. My vote would be to keep things as is. >>>>>> >>>>> In my experience, checkpatch is smart enough to recognise when a long >>>>> line overflows the 80 character limit because of a single long string, >>>>> so the two options are not mutually exclusive. In other words, long >>>>> lines are not allowed except in the case where shortening the line >>>>> involves splitting a string. There may be a small amount of work in >>>>> getting checkpatch happy, i.e. by putting the string on a line on it's >>>>> own, but we can indeed have our cake and eat it too in this case. >>>> >>>> I can't seem to get around warnings without ignoring either SPLIT_STRING or >>>> LONG_LINE_STRING as of Linux v4.14-rc3's checkpatch.pl. I think you can only >>>> get around them by fooling it somehow. You really need to ignore at least >>>> LONG_LINE_STRING to meet the requirements of the commit log. >>>> >>>> However SPLIT_STRING still looks necessary to address part of cf75514c8e2e >>>> ("devtools: ignore warning on long log string"): >>>> >>>> "...lines that make use of PRIx64 with string concatenation will still be >>>> flagged if the beginning of the last string fragment begins after the 80 >>>> character threshold." >>>> >>>> It's not all that uncommon in my opinion. >>>> >>> If you have PRIx64 in it, it's not part of a literal string you would >>> grep, so it's reasonable to split there. The user cannot know what the >>> specific %x formatting character used is. >> >> I agree, however in that case checkpatch would complain because our >> configuration doesn't specify to ignore SPLIT_STRING since there is no comma >> separator when concatenating them. >> >> My point is that the occasional exception is still necessary for split >> strings, that ignoring LONG_LINE_STRING must remain either way and >> unnecessary warnings cause more harm than good (they need to be worked >> around if we enforce this rule). >> >> In short, long/split strings acceptability assessment should be left to >> reviewers, as it cannot be automated in all cases through checkpatch.pl. >> > > This patch is waiting in patchwork for a long time now. > > My experience is same with Adrien's, if 'LONG_LINE_STRING' is not ignored, it > will complain about long log messages, so removing 'LONG_LINE_STRING' > contradicts with the reason of the patch described in the commit log. > > Perhaps it can be an option to remove only 'SPLIT_STRING' from ignore list, to > detect split messages. > > But overall, I am updating this patch as "Change Requested", if there is a > demand for ignoring 'SPLIT_STRING' please send a new version. > Sorry for the noise, I keep forgetting this, for reference the patch mentioned: https://patches.dpdk.org/patch/29438/