From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [PATCH] ethdev: add function name to log message Date: Tue, 16 Oct 2018 16:55:43 +0100 Message-ID: <2ed85850-f6f3-1f99-375b-85910479a9a2@intel.com> References: <20181011175940.6800-1-stephen@networkplumber.org> <98717fc3-c3dd-cc4f-e5ff-b5310e47d6ee@intel.com> <696e6f90-3d0c-acd4-d72d-bbebe1ff6f54@intel.com> <20181012124357.GR18937@6wind.com> <20181012075424.79383f32@xeon-e3> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: thomas@monjalon.net, dev@dpdk.org To: Stephen Hemminger , Adrien Mazarguil , Gaetan Rivet Return-path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 0CE0E1B125 for ; Tue, 16 Oct 2018 17:55:46 +0200 (CEST) In-Reply-To: <20181012075424.79383f32@xeon-e3> 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 10/12/2018 3:54 PM, Stephen Hemminger wrote: > On Fri, 12 Oct 2018 14:43:57 +0200 > Adrien Mazarguil wrote: > >> On Fri, Oct 12, 2018 at 11:45:01AM +0100, Ferruh Yigit wrote: >>> On 10/12/2018 11:42 AM, Ferruh Yigit wrote: >>>> On 10/11/2018 6:59 PM, Stephen Hemminger wrote: >>>>> @@ -161,8 +161,9 @@ extern "C" { >>>>> >>>>> extern int rte_eth_dev_logtype; >>>>> >>>>> -#define RTE_ETHDEV_LOG(level, ...) \ >>>>> - rte_log(RTE_LOG_ ## level, rte_eth_dev_logtype, "" __VA_ARGS__) >>>>> +#define RTE_ETHDEV_LOG(level, fmt, ...) \ >>>>> + rte_log(RTE_LOG_ ## level, rte_eth_dev_logtype, \ >>>>> + "%s():" fmt, __func__, ## __VA_ARGS__) >>>> >>>> +1 to adding function name, but >>>> >>>> failsafe is giving build error [1] with clang because of ## usage [2], that is >>>> why I add this as ` "" __VA_ARGS__` at first place but you can't do this trick >>>> if __VA_ARGS__ used after fmt. >>>> >>>> I am not aware of a solution for this, __VA_OPT__(,) also didn't worked with clang. >>> >>> +cc Adrien & Gaetan, >>> >>> I saw Adrien put some "workaround" to this for mlx5 >> >> Yes, through RTE_FMT() (rte_common.h). Something like this: >> >> #define RTE_ETHDEV_LOG(level, fmt, ...) \ >> rte_log(RTE_LOG_ ## level, \ >> rte_eth_dev_logtype, \ >> "%s():" fmt, \ >> __func__, \ >> ## __VA_ARGS__) >> >> Can be rewritten like that: >> >> #define RTE_ETHDEV_LOG(level, ...) \ >> rte_log(RTE_LOG_ ## level, \ >> rte_eth_dev_logtype, \ >> RTE_FMT("%s():" RTE_FMT_HEAD(__VA_ARGS__,), \ >> __func__, \ >> RTE_FMT_TAIL(__VA_ARGS__,))) >> >> Although not too pretty and convenient, it does the job. In short: >> >> - Remove "fmt" argument from prototype. >> - Enclose format string and its arguments in RTE_FMT(). >> - Replace "fmt" with RTE_FMT_HEAD(__VA_ARGS__,). >> - Replace "## __VA_ARGS__" with RTE_FMT_TAIL(__VA_ARGS__,). >> - Yes, trailing commas are mandatory in RTE_FMT_(HEAD|TAIL)(). >> - Note it quietly appends a dummy "%.0s" argument to the format string. >> >>>> [1] >>>> .../build/include/rte_ethdev.h:166:26: error: token pasting of ',' and >>>> __VA_ARGS__ is a GNU extension [-Werror,-Wgnu-zero-variadic-macro-arguments] >>>> "%s():" fmt, __func__, ## __VA_ARGS__) >>>> ^ >>>> >>>> [2] >>>> This seems because of "-pedantic" argument driver uses, and other PMDs using >>>> "-pedantic", like mlx, will have same error although they are disable by >>>> default and error not observed in default build. >>>> >>> >> > > Since zero varadic macros is a GNU extension, maybe just adding GNU source? I think `-pedantic` is preventing using extension whether we have `_GNU_SOURCE` or not. Gaetan, Why we have `-pedantic` option enabled for failsafe?