On 12/03/2021 18:17, Thomas Monjalon wrote:
> The option --log-level was not completely described in the usage text,
> and it was difficult to guess the names of the log types and levels.
>
> A new value "help" is accepted after --log-level to give more details
> about the syntax and listing the log types and levels.
>
> The array "levels" used for level name parsing is replaced with
> a (modified) existing function which was used in rte_log_dump().
>
> The new function rte_log_list_types() is exported in the API
> for allowing an application to give this info to the user
> if not exposing the EAL option --log-level.
> The list of log types cannot include all drivers if not linked in the
> application (shared object plugin case).
>
> Signed-off-by: Thomas Monjalon <tho...@monjalon.net>
> ---
> lib/librte_eal/common/eal_common_log.c | 24 +++++++++---
> lib/librte_eal/common/eal_common_options.c | 44 +++++++++++++++-------
> lib/librte_eal/common/eal_log.h | 5 +++
> lib/librte_eal/include/rte_log.h | 11 ++++++
> lib/librte_eal/version.map | 3 ++
> 5 files changed, 69 insertions(+), 18 deletions(-)
>
> diff --git a/lib/librte_eal/common/eal_common_log.c
> b/lib/librte_eal/common/eal_common_log.c
> index 40cac36f89..d695b04068 100644
> --- a/lib/librte_eal/common/eal_common_log.c
> +++ b/lib/librte_eal/common/eal_common_log.c
> @@ -397,12 +397,12 @@ RTE_INIT_PRIO(log_init, LOG)
> rte_logs.dynamic_types_len = RTE_LOGTYPE_FIRST_EXT_ID;
> }
>
> -static const char *
> -loglevel_to_string(uint32_t level)
> +const char *
> +eal_log_level2str(uint32_t level)
> {
> switch (level) {
> case 0: return "disabled";
> - case RTE_LOG_EMERG: return "emerg";
> + case RTE_LOG_EMERG: return "emergency";
> case RTE_LOG_ALERT: return "alert";
> case RTE_LOG_CRIT: return "critical";
> case RTE_LOG_ERR: return "error";
> @@ -414,6 +414,20 @@ loglevel_to_string(uint32_t level)
> }
> }
>
> +/* Dump name of each logtype, one per line. */
> +void
> +rte_log_list_types(FILE *out, const char *prefix)
> +{
> + size_t type;
> +
> + for (type = 0; type < rte_logs.dynamic_types_len; ++type) {
> + if (rte_logs.dynamic_types[type].name == NULL)
> + continue;
> + fprintf(out, "%s%s\n",
> + prefix, rte_logs.dynamic_types[type].name);
> + }
> +}
> +
> /* dump global level and registered log types */
> void
> rte_log_dump(FILE *f)
> @@ -421,14 +435,14 @@ rte_log_dump(FILE *f)
> size_t i;
>
> fprintf(f, "global log level is %s\n",
> - loglevel_to_string(rte_log_get_global_level()));
> + eal_log_level2str(rte_log_get_global_level()));
>
> for (i = 0; i < rte_logs.dynamic_types_len; i++) {
> if (rte_logs.dynamic_types[i].name == NULL)
> continue;
> fprintf(f, "id %zu: %s, level is %s\n",
> i, rte_logs.dynamic_types[i].name,
> - loglevel_to_string(rte_logs.dynamic_types[i].loglevel));
> + eal_log_level2str(rte_logs.dynamic_types[i].loglevel));
> }
> }
>
> diff --git a/lib/librte_eal/common/eal_common_options.c
> b/lib/librte_eal/common/eal_common_options.c
> index 2df3ae04ea..1da6583d71 100644
> --- a/lib/librte_eal/common/eal_common_options.c
> +++ b/lib/librte_eal/common/eal_common_options.c
> @@ -1227,19 +1227,31 @@ eal_parse_syslog(const char *facility, struct
> internal_config *conf)
> }
> #endif
>
> +static void
> +eal_log_usage(void)
> +{
> + unsigned int level;
> +
> + printf("Log type is a pattern matching items of this list"
> + " (plugins may be missing):\n");
> + rte_log_list_types(stdout, "\t");
> + printf("\n");
> + printf("Syntax using globbing pattern: ");
> + printf("--"OPT_LOG_LEVEL" pattern:level\n");
> + printf("Syntax using regular expression: ");
> + printf("--"OPT_LOG_LEVEL" regexp,level\n");
> + printf("Syntax for the global level: ");
> + printf("--"OPT_LOG_LEVEL" level\n");
> + printf("Logs are emitted if allowed by both global and specific
> levels.\n");
> + printf("\n");
> + printf("Log level can be a number or the first letters of its name:\n");
> + for (level = 1; level <= RTE_LOG_MAX; level++)
> + printf("\t%d %s\n", level, eal_log_level2str(level));
> +}
> +
> static int
> eal_parse_log_priority(const char *level)
> {
> - static const char * const levels[] = {
> - [RTE_LOG_EMERG] = "emergency",
> - [RTE_LOG_ALERT] = "alert",
> - [RTE_LOG_CRIT] = "critical",
> - [RTE_LOG_ERR] = "error",
> - [RTE_LOG_WARNING] = "warning",
> - [RTE_LOG_NOTICE] = "notice",
> - [RTE_LOG_INFO] = "info",
> - [RTE_LOG_DEBUG] = "debug",
> - };
> size_t len = strlen(level);
> unsigned long tmp;
> char *end;
> @@ -1250,7 +1262,7 @@ eal_parse_log_priority(const char *level)
>
> /* look for named values, skip 0 which is not a valid level */
> for (i = 1; i <= RTE_LOG_MAX; i++) {
> - if (strncmp(levels[i], level, len) == 0)
> + if (strncmp(eal_log_level2str(i), level, len) == 0)
> return i;
> }
>
> @@ -1274,6 +1286,11 @@ eal_parse_log_level(const char *arg)
> char *str, *level;
> int priority;
>
> + if (strcmp(arg, "help") == 0) {
So I think the convention is to support both "?" and "help".
Qemu does this at least.
> + eal_log_usage();
> + exit(EXIT_SUCCESS);
> + }
> +
> str = strdup(arg);
> if (str == NULL)
> return -1;
> @@ -2067,9 +2084,10 @@ eal_common_usage(void)
> #ifndef RTE_EXEC_ENV_WINDOWS
> " --"OPT_SYSLOG" Set syslog facility\n"
> #endif
> - " --"OPT_LOG_LEVEL"=<int> Set global log level\n"
> - " --"OPT_LOG_LEVEL"=<type-match>:<int>\n"
> + " --"OPT_LOG_LEVEL"=<level> Set global log level\n"
> + " --"OPT_LOG_LEVEL"=<type-match>:<level>\n"
> " Set specific log level\n"
> + " --"OPT_LOG_LEVEL"=help Show log types and levels\n"
> #ifndef RTE_EXEC_ENV_WINDOWS
> " --"OPT_TRACE"=<regex-match>\n"
> " Enable trace based on regular expression
> trace name.\n"
> diff --git a/lib/librte_eal/common/eal_log.h b/lib/librte_eal/common/eal_log.h
> index 684650a17b..c784fa6043 100644
> --- a/lib/librte_eal/common/eal_log.h
> +++ b/lib/librte_eal/common/eal_log.h
> @@ -24,4 +24,9 @@ void eal_log_set_default(FILE *default_log);
> int eal_log_save_regexp(const char *regexp, uint32_t level);
> int eal_log_save_pattern(const char *pattern, uint32_t level);
>
> +/*
> + * Convert log level to string.
> + */
> +const char *eal_log_level2str(uint32_t level);
> +
> #endif /* EAL_LOG_H */
> diff --git a/lib/librte_eal/include/rte_log.h
> b/lib/librte_eal/include/rte_log.h
> index 394e8682b9..e6192892c3 100644
> --- a/lib/librte_eal/include/rte_log.h
> +++ b/lib/librte_eal/include/rte_log.h
> @@ -240,6 +240,17 @@ int rte_log_register(const char *name);
> __rte_experimental
> int rte_log_register_type_and_pick_level(const char *name, uint32_t
> level_def);
>
> +/**
> + * Dump name of each logtype, one per line.
> + *
> + * @param out
> + * Stream where the list is sent.
> + * @param prefix
> + * String preceding each logtype in the output.
> + */
> +__rte_experimental
> +void rte_log_list_types(FILE *out, const char *prefix);
> +
> /**
> * Dump log information.
> *
> diff --git a/lib/librte_eal/version.map b/lib/librte_eal/version.map
> index fce90a112f..6b7876a0b9 100644
> --- a/lib/librte_eal/version.map
> +++ b/lib/librte_eal/version.map
> @@ -412,6 +412,9 @@ EXPERIMENTAL {
> rte_thread_tls_key_delete;
> rte_thread_tls_value_get;
> rte_thread_tls_value_set;
> +
> + # added in 21.05
> + rte_log_list_types;
> };
>
> INTERNAL {
>
