[dpdk-dev] [PATCH] rcu: avoid literal suffix warning in C++ mode

[Honnappa Nagarahalli]

Hi Dmitry,
	Thanks for the patch, few nits inline.

> -----Original Message-----
> From: Dmitry Kozlyuk <dmitry.kozliuk at gmail.com>
> Sent: Monday, August 31, 2020 4:38 PM
> To: dev at dpdk.org
> Cc: Dmitry Kozlyuk <dmitry.kozliuk at gmail.com>; stable at dpdk.org;
> Honnappa Nagarahalli <Honnappa.Nagarahalli at arm.com>
> Subject: [PATCH] rcu: avoid literal suffix warning in C++ mode
                                  ^^^ should be lib/rcu
> 
> Sequences like "value = %"PRIu64 (no space before PRIu64) are parsed as a
> single preprocessor token, user-defined-string-literal, in C++11 onwards.
> While modern compilers are smart enough to parse this properly, GCC 9.3.0
> generates warnings like:
> 
>     rte_rcu_qsbr.h:555:26: warning: invalid suffix on literal; C++11
>     requires a space between literal and string macro [-Wliteral-suffix]
> 
> Add spaces around format specifier macros to make public headers
> compatible with C++ without causing warnings.
> 
> Fixes: 64994b56c ("rcu: add RCU library supporting QSBR mechanism")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk at gmail.com>
> ---
>  lib/librte_rcu/rte_rcu_qsbr.h | 14 +++++++-------
To be consistent, can you please do similar changes in rte_rcu_qsbr.c file?

>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/librte_rcu/rte_rcu_qsbr.h b/lib/librte_rcu/rte_rcu_qsbr.h
> index a98e8f0f8..aa237cf75 100644
> --- a/lib/librte_rcu/rte_rcu_qsbr.h
> +++ b/lib/librte_rcu/rte_rcu_qsbr.h
> @@ -552,7 +552,7 @@ rte_rcu_qsbr_quiescent(struct rte_rcu_qsbr *v,
> unsigned int thread_id)
>  		__atomic_store_n(&v->qsbr_cnt[thread_id].cnt,
>  					 t, __ATOMIC_RELEASE);
> 
> -	__RTE_RCU_DP_LOG(DEBUG, "%s: update: token = %"PRIu64",
> Thread ID = %d",
> +	__RTE_RCU_DP_LOG(DEBUG, "%s: update: token = %" PRIu64 ",
> Thread ID =
> +%d",
>  		__func__, t, thread_id);
>  }
> 
> @@ -580,13 +580,13 @@ __rte_rcu_qsbr_check_selective(struct
> rte_rcu_qsbr *v, uint64_t t, bool wait)
>  		while (bmap) {
>  			j = __builtin_ctzl(bmap);
>  			__RTE_RCU_DP_LOG(DEBUG,
> -				"%s: check: token = %"PRIu64", wait = %d, Bit
> Map = 0x%"PRIx64", Thread ID = %d",
> +				"%s: check: token = %" PRIu64 ", wait = %d,
> Bit Map = 0x%" PRIx64
> +", Thread ID = %d",
>  				__func__, t, wait, bmap, id + j);
>  			c = __atomic_load_n(
>  					&v->qsbr_cnt[id + j].cnt,
>  					__ATOMIC_ACQUIRE);
>  			__RTE_RCU_DP_LOG(DEBUG,
> -				"%s: status: token = %"PRIu64", wait = %d,
> Thread QS cnt = %"PRIu64", Thread ID = %d",
> +				"%s: status: token = %" PRIu64 ", wait = %d,
> Thread QS cnt = %"
> +PRIu64 ", Thread ID = %d",
>  				__func__, t, wait, c, id+j);
> 
>  			/* Counter is not checked for wrap-around condition
> @@ -643,12 +643,12 @@ __rte_rcu_qsbr_check_all(struct rte_rcu_qsbr *v,
> uint64_t t, bool wait)
> 
>  	for (i = 0, cnt = v->qsbr_cnt; i < v->max_threads; i++, cnt++) {
>  		__RTE_RCU_DP_LOG(DEBUG,
> -			"%s: check: token = %"PRIu64", wait = %d, Thread ID
> = %d",
> +			"%s: check: token = %" PRIu64 ", wait = %d, Thread
> ID = %d",
>  			__func__, t, wait, i);
>  		while (1) {
>  			c = __atomic_load_n(&cnt->cnt,
> __ATOMIC_ACQUIRE);
>  			__RTE_RCU_DP_LOG(DEBUG,
> -				"%s: status: token = %"PRIu64", wait = %d,
> Thread QS cnt = %"PRIu64", Thread ID = %d",
> +				"%s: status: token = %" PRIu64 ", wait = %d,
> Thread QS cnt = %"
> +PRIu64 ", Thread ID = %d",
>  				__func__, t, wait, c, i);
> 
>  			/* Counter is not checked for wrap-around condition
> @@ -725,10 +725,10 @@ rte_rcu_qsbr_check(struct rte_rcu_qsbr *v,
> uint64_t t, bool wait)
>  	/* Check if all the readers have already acknowledged this token */
>  	if (likely(t <= v->acked_token)) {
>  		__RTE_RCU_DP_LOG(DEBUG,
> -			"%s: check: token = %"PRIu64", wait = %d",
> +			"%s: check: token = %" PRIu64 ", wait = %d",
>  			__func__, t, wait);
>  		__RTE_RCU_DP_LOG(DEBUG,
> -			"%s: status: least acked token = %"PRIu64"",
> +			"%s: status: least acked token = %" PRIu64,
>  			__func__, v->acked_token);
>  		return 1;
>  	}
> --
> 2.25.4