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Subject: Re: [PATCH 4/6] perf config: Add support for writing configs to a
 config file
To: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
References: <1478241862-31230-1-git-send-email-treeze.taeung@gmail.com>
 <1478241862-31230-5-git-send-email-treeze.taeung@gmail.com>
 <20161114160442.GD26543@kernel.org>
Cc: linux-kernel@vger.kernel.org, Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>, Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, Wang Nan <wangnan0@huawei.com>,
        Nambong Ha <over3025@gmail.com>, Wookje Kwon <aweee0@gmail.com>
From: Taeung Song <treeze.taeung@gmail.com>
Message-ID: <745d8c99-18ed-0ee8-a327-1ff896b5a344@gmail.com>
Date: Tue, 15 Nov 2016 02:00:38 +0900
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Thank you for your review.

I have a question at the very bottom
(skip v2 I sent lately or not ?).

On 11/15/2016 01:04 AM, Arnaldo Carvalho de Melo wrote:
> Em Fri, Nov 04, 2016 at 03:44:20PM +0900, Taeung Song escreveu:
>> Add setting feature that can add config variables with their values
>> to a config file (i.e. user or system config file) or modify
>> config key-value pairs in a config file.
>> For the syntax examples,
>>
>>     perf config [<file-option>] [section.name[=value] ...]
>>
>> e.g. You can set the ui.show-headers to false with
>>
>>     # perf config ui.show-headers=false
>>
>> If you want to add or modify several config items, you can do like
>>
>>     # perf config annotate.show_nr_jumps=false kmem.default=slab
>
> This works, but has some problems, see below:
>
>> Cc: Namhyung Kim <namhyung@kernel.org>
>> Cc: Jiri Olsa <jolsa@kernel.org>
>> Cc: Wang Nan <wangnan0@huawei.com>
>> Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
>> ---
>>  tools/perf/builtin-config.c | 66 ++++++++++++++++++++++++++++++++++++++++-----
>>  tools/perf/util/config.c    |  6 +++++
>>  tools/perf/util/config.h    |  2 ++
>>  3 files changed, 68 insertions(+), 6 deletions(-)
>>
>> diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
>> index fe253f3..5313702 100644
>> --- a/tools/perf/builtin-config.c
>> +++ b/tools/perf/builtin-config.c
>> @@ -17,7 +17,7 @@
>>  static bool use_system_config, use_user_config;
>>
>>  static const char * const config_usage[] = {
>> -	"perf config [<file-option>] [options] [section.name ...]",
>> +	"perf config [<file-option>] [options] [section.name[=value] ...]",
>>  	NULL
>>  };
>>
>> @@ -33,6 +33,37 @@ static struct option config_options[] = {
>>  	OPT_END()
>>  };
>>
>> +static int set_config(struct perf_config_set *set, const char *file_name,
>> +		      const char *var, const char *value)
>> +{
>> +	struct perf_config_section *section = NULL;
>> +	struct perf_config_item *item = NULL;
>> +	const char *first_line = "# this file is auto-generated.";
>> +	FILE *fp = fopen(file_name, "w");
>> +
>> +	if (!fp)
>> +		return -1;
>> +	if (set == NULL)
>> +		return -1;
>
> So, here fp is left open? I'm fixing this...

Understood. Sorry, I missed out it.

>> +	perf_config_set__collect(set, var, value);
>> +	fprintf(fp, "%s\n", first_line);
>> +
>> +	/* overwrite configvariables */
>                          missing space?

Oops.. I missed a white space between two words.

>> +	perf_config_items__for_each_entry(&set->sections, section) {
>> +		fprintf(fp, "[%s]\n", section->name);
>> +
>> +		perf_config_items__for_each_entry(&section->items, item) {
>> +			if (item->value)
>> +				fprintf(fp, "\t%s = %s\n",
>> +					item->name, item->value);
>> +		}
>> +	}
>> +	fclose(fp);
>> +
>> +	return 0;
>> +}
>> +
>>  static int show_spec_config(struct perf_config_set *set, const char *var)
>>  {
>>  	struct perf_config_section *section;
>> @@ -82,7 +113,7 @@ static int show_config(struct perf_config_set *set)
>>  	return 0;
>>  }
>>
>> -static int parse_config_arg(char *arg, char **var)
>> +static int parse_config_arg(char *arg, char **var, char **value)
>>  {
>>  	const char *last_dot = strchr(arg, '.');
>>
>> @@ -99,7 +130,21 @@ static int parse_config_arg(char *arg, char **var)
>>  		return -1;
>>  	}
>>
>> -	*var = arg;
>> +	*value = strchr(arg, '=');
>> +	if (*value == NULL)
>> +		*var = arg;
>> +	else if (!strcmp(*value, "=")) {
>> +		pr_err("The config variable does not contain a value: %s\n", arg);
>> +		return -1;
>> +	} else {
>> +		*value = *value + 1; /* excluding a first character '=' */
>> +		*var = strsep(&arg, "=");
>> +		if (*var[0] == '\0') {
>> +			pr_err("invalid config variable: %s\n", arg);
>> +			return -1;
>> +		}
>> +	}
>> +

Here and..

>>
>> @@ -153,7 +198,8 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
>>  	default:
>>  		if (argc) {
>>  			for (i = 0; argv[i]; i++) {
>> -				char *var, *arg = strdup(argv[i]);
>> +				char *var, *value;
>> +				char *arg = strdup(argv[i]);
>>
>>  				if (!arg) {
>>  					pr_err("%s: strdup failed\n", __func__);
>> @@ -161,13 +207,21 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
>>  					break;
>>  				}
>>
>> -				if (parse_config_arg(arg, &var) < 0) {
>> +				if (parse_config_arg(arg, &var, &value) < 0) {
>>  					free(arg);
>>  					ret = -1;
>>  					break;
>>  				}
>>
>> -				ret = show_spec_config(set, var);
>> +				if (value == NULL)
>> +					ret = show_spec_config(set, var);
>> +				else {
>> +					const char *config_filename = config_exclusive_filename;
>> +
>> +					if (!config_exclusive_filename)
>> +						config_filename = user_config;
>> +					ret = set_config(set, config_filename, var, value);
>> +				}
>>  				free(arg);

Here, the parts are a bit different than v2 patchset I sent lately.
I refactored parse_config_arg() and a bit modify parsing
config arguments in cmd_config().

Is it better to just skip v2 patchset I sent ?
And remake new patchset regarding today your feedback ?

Or would I make v3 that adopts v2 I sent?


Thanks,
Taeung

>>  			}
>>  		} else
>> diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
>> index 18dae74..c8fb65d 100644
>> --- a/tools/perf/util/config.c
>> +++ b/tools/perf/util/config.c
>> @@ -602,6 +602,12 @@ static int collect_config(const char *var, const char *value,
>>  	return -1;
>>  }
>>
>> +int perf_config_set__collect(struct perf_config_set *set,
>> +			     const char *var, const char *value)
>> +{
>> +	return collect_config(var, value, set);
>> +}
>> +
>>  static int perf_config_set__init(struct perf_config_set *set)
>>  {
>>  	int ret = -1;
>> diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
>> index 6f813d4..0fcdb8c 100644
>> --- a/tools/perf/util/config.h
>> +++ b/tools/perf/util/config.h
>> @@ -33,6 +33,8 @@ const char *perf_etc_perfconfig(void);
>>
>>  struct perf_config_set *perf_config_set__new(void);
>>  void perf_config_set__delete(struct perf_config_set *set);
>> +int perf_config_set__collect(struct perf_config_set *set,
>> +			     const char *var, const char *value);
>>  void perf_config__init(void);
>>  void perf_config__exit(void);
>>  void perf_config__refresh(void);
>> --
>> 2.7.4