Re: [PATCH v9 1/7] perf config: Introduce default_config_section and default_config_item for default config key-value pairs

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Mon, Nov 28, 2016 at 05:51:12PM +0900, Taeung Song escreveu:
> When initializing default perf config values,
> we currently use values of actual type(int, bool, char *, etc.).
> 
> For example,
> If there isn't a user config value for 'annotate.use_offset'
> config variable at ~/.perfconfig,
> default value for it is 'true' bool type value in perf like below.
> 
> At ui/browsers/annoate.c
> 
> static struct annotate_browser_opt {
>         bool hide_src_code,
>              use_offset,
>              jump_arrows,
>              show_linenr,
>              show_nr_jumps,
>              show_total_period;
> } annotate_browser__opts = {
>         .use_offset      = true,
>         .jump_arrows     = true,
> };

And isn't this a good thing? I.e. its compact, we have just to set
values to things that are !0 (or !false), and it is close to the code
where it is used.
 
> But I suggest using 'struct default_config_section' and
> 'struct default_config_item' that can contain default config key-value pairs
> in order to initialize default config values with them, in near future.

 
> If we do, we could manage default perf config values at one spot (i.e. util/config.c)
> with default config arrays and it could be easy and simple to modify
> existing default config values or add default values for new config item.
> 
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Wang Nan <wangnan0@huawei.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: David Ahern <dsahern@gmail.com>
> Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
> ---
>  tools/perf/util/config.h | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
> index 1a59a6b..434d71c 100644
> --- a/tools/perf/util/config.h
> +++ b/tools/perf/util/config.h
> @@ -67,4 +67,33 @@ void perf_config__refresh(void);
>  	perf_config_sections__for_each_entry(&set->sections, section)		\
>  	perf_config_items__for_each_entry(&section->items, item)
>  
> +enum perf_config_type {
> +	CONFIG_TYPE_BOOL,
> +	CONFIG_TYPE_INT,
> +	CONFIG_TYPE_LONG,
> +	CONFIG_TYPE_U64,
> +	CONFIG_TYPE_FLOAT,
> +	CONFIG_TYPE_DOUBLE,
> +	CONFIG_TYPE_STRING
> +};
> +
> +struct default_config_item {
> +	const char *name;
> +	union {
> +		bool b;
> +		int i;
> +		u32 l;
> +		u64 ll;
> +		float f;
> +		double d;
> +		const char *s;
> +	} value;
> +	enum perf_config_type type;
> +};
> +
> +struct default_config_section {
> +	const char *name;
> +	const struct default_config_item *items;
> +};
> +
>  #endif /* __PERF_CONFIG_H */
> -- 
> 2.7.4