[dpdk-dev] [PATCH v2] lib/rcu: avoid literal suffix warning in C++ mode

[Honnappa Nagarahalli]

<snip>

> 
> 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. Make similar changes in C
> source for style consistency within the library.
> 
> Fixes: 64994b56c ("rcu: add RCU library supporting QSBR mechanism")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk at gmail.com>
Looks good, Thank you.
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>

> ---
> 
> v2: fix subject line, adjust C source for style consistency.
> 
>  lib/librte_rcu/rte_rcu_qsbr.c | 13 +++++++------
> lib/librte_rcu/rte_rcu_qsbr.h | 14 +++++++-------
>  2 files changed, 14 insertions(+), 13 deletions(-)
> 
> diff --git a/lib/librte_rcu/rte_rcu_qsbr.c b/lib/librte_rcu/rte_rcu_qsbr.c index
> aebfdb0da..a5f9de326 100644
> --- a/lib/librte_rcu/rte_rcu_qsbr.c
> +++ b/lib/librte_rcu/rte_rcu_qsbr.c
> @@ -244,10 +244,10 @@ rte_rcu_qsbr_dump(FILE *f, struct rte_rcu_qsbr *v)
> 
>  	fprintf(f, "\n");
> 
> -	fprintf(f, "  Token = %"PRIu64"\n",
> +	fprintf(f, "  Token = %" PRIu64 "\n",
>  			__atomic_load_n(&v->token, __ATOMIC_ACQUIRE));
> 
> -	fprintf(f, "  Least Acknowledged Token = %"PRIu64"\n",
> +	fprintf(f, "  Least Acknowledged Token = %" PRIu64 "\n",
>  			__atomic_load_n(&v->acked_token,
> __ATOMIC_ACQUIRE));
> 
>  	fprintf(f, "Quiescent State Counts for readers:\n"); @@ -257,7 +257,7
> @@ rte_rcu_qsbr_dump(FILE *f, struct rte_rcu_qsbr *v)
>  		id = i << __RTE_QSBR_THRID_INDEX_SHIFT;
>  		while (bmap) {
>  			t = __builtin_ctzl(bmap);
> -			fprintf(f, "thread ID = %u, count = %"PRIu64", lock
> count = %u\n",
> +			fprintf(f, "thread ID = %u, count = %" PRIu64 ", lock
> count = %u\n",
>  				id + t,
>  				__atomic_load_n(
>  					&v->qsbr_cnt[id + t].cnt,
> @@ -402,7 +402,7 @@ int rte_rcu_qsbr_dq_enqueue(struct
> rte_rcu_qsbr_dq *dq, void *e)
>  		 * other issues.
>  		 */
>  		rte_log(RTE_LOG_INFO, rte_rcu_log_type,
> -			"%s(): Skipped enqueuing token = %"PRIu64"\n",
> +			"%s(): Skipped enqueuing token = %" PRIu64 "\n",
>  			__func__, dq_elem->token);
> 
>  		rte_errno = ENOSPC;
> @@ -410,7 +410,8 @@ int rte_rcu_qsbr_dq_enqueue(struct
> rte_rcu_qsbr_dq *dq, void *e)
>  	}
> 
>  	rte_log(RTE_LOG_INFO, rte_rcu_log_type,
> -		"%s(): Enqueued token = %"PRIu64"\n", __func__, dq_elem-
> >token);
> +		"%s(): Enqueued token = %" PRIu64 "\n",
> +		__func__, dq_elem->token);
> 
>  	return 0;
>  }
> @@ -449,7 +450,7 @@ rte_rcu_qsbr_dq_reclaim(struct rte_rcu_qsbr_dq
> *dq, unsigned int n,
>  		rte_ring_dequeue_elem_finish(dq->r, 1);
> 
>  		rte_log(RTE_LOG_INFO, rte_rcu_log_type,
> -			"%s(): Reclaimed token = %"PRIu64"\n",
> +			"%s(): Reclaimed token = %" PRIu64 "\n",
>  			__func__, dq_elem->token);
> 
>  		dq->free_fn(dq->p, dq_elem->elem, 1); 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