[RFC v2 11/14] log: add a per line log helper

[fengchengwen]

Acked-by: Chengwen Feng <fengchengwen at huawei.com>

On 2023/12/8 22:59, David Marchand wrote:
> gcc builtin __builtin_strchr can be used as a static assertion to check
> whether passed format strings contain a \n.
> This can be useful to detect double \n in log messages.
> 
> Signed-off-by: David Marchand <david.marchand at redhat.com>
> ---
> Changes since RFC v1:
> - added a check in checkpatches.sh,
> 
> ---
>  devtools/checkpatches.sh |  8 ++++++++
>  lib/log/rte_log.h        | 21 +++++++++++++++++++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/devtools/checkpatches.sh b/devtools/checkpatches.sh
> index 10b79ca2bc..10d1bf490b 100755
> --- a/devtools/checkpatches.sh
> +++ b/devtools/checkpatches.sh
> @@ -53,6 +53,14 @@ print_usage () {
>  check_forbidden_additions() { # <patch>
>  	res=0
>  
> +	# refrain from new calls to RTE_LOG
> +	awk -v FOLDERS="lib" \
> +		-v EXPRESSIONS="RTE_LOG\\\(" \
> +		-v RET_ON_FAIL=1 \
> +		-v MESSAGE='Prefer RTE_LOG_LINE' \
> +		-f $(dirname $(readlink -f $0))/check-forbidden-tokens.awk \
> +		"$1" || res=1
> +
>  	# refrain from new additions of rte_panic() and rte_exit()
>  	# multiple folders and expressions are separated by spaces
>  	awk -v FOLDERS="lib drivers" \
> diff --git a/lib/log/rte_log.h b/lib/log/rte_log.h
> index 27fb6129a7..da7e672e81 100644
> --- a/lib/log/rte_log.h
> +++ b/lib/log/rte_log.h
> @@ -17,6 +17,7 @@
>  extern "C" {
>  #endif
>  
> +#include <assert.h>
>  #include <stdint.h>
>  #include <stdio.h>
>  #include <stdarg.h>
> @@ -358,6 +359,26 @@ int rte_vlog(uint32_t level, uint32_t logtype, const char *format, va_list ap)
>  		 RTE_LOGTYPE_ ## t, # t ": " __VA_ARGS__) :	\
>  	 0)
>  
> +#ifdef RTE_TOOLCHAIN_GCC
> +#define RTE_LOG_CHECK_NO_NEWLINE(fmt) \
> +	static_assert(!__builtin_strchr(fmt, '\n'), \
> +		"This log format string contains a \\n")
> +#else
> +#define RTE_LOG_CHECK_NO_NEWLINE(...)
> +#endif
> +
> +#define RTE_LOG_LINE(l, t, ...) do { \
> +	RTE_LOG_CHECK_NO_NEWLINE(RTE_FMT_HEAD(__VA_ARGS__,)); \
> +	RTE_LOG(l, t, RTE_FMT(RTE_FMT_HEAD(__VA_ARGS__,) "\n", \
> +		RTE_FMT_TAIL(__VA_ARGS__ ,))); \
> +} while (0)
> +
> +#define RTE_LOG_DP_LINE(l, t, ...) do { \
> +	RTE_LOG_CHECK_NO_NEWLINE(RTE_FMT_HEAD(__VA_ARGS__,)); \
> +	RTE_LOG_DP(l, t, RTE_FMT(RTE_FMT_HEAD(__VA_ARGS__,) "\n", \
> +		RTE_FMT_TAIL(__VA_ARGS__ ,))); \
> +} while (0)
> +
>  #define RTE_LOG_REGISTER_IMPL(type, name, level)			    \
>  int type;								    \
>  RTE_INIT(__##type)							    \
>