Re: [PATCH v3 09/17] perf: util: add general function to parse sublevel options

[Changbin Du <changbin.du@gmail.com>]

On Wed, Jul 08, 2020 at 02:34:23PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Thu, Jul 09, 2020 at 12:45:57AM +0800, Changbin Du escreveu:
> > This factors out a general function perf_parse_sublevel_options() to parse
> > sublevel options. The 'sublevel' options is something like the '--debug'
> > options which allow more sublevel options.
> 
> Please don't add stuff to util.h/util.c, its too generic a name and
> we've been trying to move things to more appropriate locations, so
> follow the example of:
> 
>   [acme@quaco perf]$ ls -la tools/perf/util/parse-regs-options.*
>   -rw-rw-r--. 1 acme acme 1932 Feb 12 15:11 tools/perf/util/parse-regs-options.c
>   -rw-rw-r--. 1 acme acme  316 Dec 20  2019 tools/perf/util/parse-regs-options.h
>   [acme@quaco perf]$
>
I crated files util/parse-sublevel-options.c and util/parse-sublevel-options.h
to hold this new function.

> Good job identifying this code and reusing it!
> 
> - Arnaldo
>  
> > Signed-off-by: Changbin Du <changbin.du@gmail.com>
> > ---
> >  tools/perf/util/debug.c | 61 ++++++++++++-----------------------------
> >  tools/perf/util/util.c  | 56 +++++++++++++++++++++++++++++++++++++
> >  tools/perf/util/util.h  |  7 +++++
> >  3 files changed, 80 insertions(+), 44 deletions(-)
> > 
> > diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
> > index adb656745ecc..79999c57a609 100644
> > --- a/tools/perf/util/debug.c
> > +++ b/tools/perf/util/debug.c
> > @@ -20,6 +20,7 @@
> >  #include "target.h"
> >  #include "ui/helpline.h"
> >  #include "ui/ui.h"
> > +#include "util/util.h"
> >  
> >  #include <linux/ctype.h>
> >  
> > @@ -173,65 +174,37 @@ void trace_event(union perf_event *event)
> >  		     trace_event_printer, event);
> >  }
> >  
> > -static struct debug_variable {
> > -	const char *name;
> > -	int *ptr;
> > -} debug_variables[] = {
> > -	{ .name = "verbose",		.ptr = &verbose },
> > -	{ .name = "ordered-events",	.ptr = &debug_ordered_events},
> > -	{ .name = "stderr",		.ptr = &redirect_to_stderr},
> > -	{ .name = "data-convert",	.ptr = &debug_data_convert },
> > -	{ .name = "perf-event-open",	.ptr = &debug_peo_args },
> > +static struct sublevel_option debug_opts[] = {
> > +	{ .name = "verbose",		.value_ptr = &verbose },
> > +	{ .name = "ordered-events",	.value_ptr = &debug_ordered_events},
> > +	{ .name = "stderr",		.value_ptr = &redirect_to_stderr},
> > +	{ .name = "data-convert",	.value_ptr = &debug_data_convert },
> > +	{ .name = "perf-event-open",	.value_ptr = &debug_peo_args },
> >  	{ .name = NULL, }
> >  };
> >  
> >  int perf_debug_option(const char *str)
> >  {
> > -	struct debug_variable *var = &debug_variables[0];
> > -	char *vstr, *s = strdup(str);
> > -	int v = 1;
> > -
> > -	vstr = strchr(s, '=');
> > -	if (vstr)
> > -		*vstr++ = 0;
> > -
> > -	while (var->name) {
> > -		if (!strcmp(s, var->name))
> > -			break;
> > -		var++;
> > -	}
> > -
> > -	if (!var->name) {
> > -		pr_err("Unknown debug variable name '%s'\n", s);
> > -		free(s);
> > -		return -1;
> > -	}
> > +	int ret;
> >  
> > -	if (vstr) {
> > -		v = atoi(vstr);
> > -		/*
> > -		 * Allow only values in range (0, 10),
> > -		 * otherwise set 0.
> > -		 */
> > -		v = (v < 0) || (v > 10) ? 0 : v;
> > -	}
> > +	ret = perf_parse_sublevel_options(str, debug_opts);
> > +	if (ret)
> > +		return ret;
> >  
> > -	if (quiet)
> > -		v = -1;
> > +	/* Allow only verbose value in range (0, 10), otherwise set 0. */
> > +	verbose = (verbose < 0) || (verbose > 10) ? 0 : verbose;
> >  
> > -	*var->ptr = v;
> > -	free(s);
> >  	return 0;
> >  }
> >  
> >  int perf_quiet_option(void)
> >  {
> > -	struct debug_variable *var = &debug_variables[0];
> > +	struct sublevel_option *opt = &debug_opts[0];
> >  
> >  	/* disable all debug messages */
> > -	while (var->name) {
> > -		*var->ptr = -1;
> > -		var++;
> > +	while (opt->name) {
> > +		*opt->value_ptr = -1;
> > +		opt++;
> >  	}
> >  
> >  	return 0;
> > diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
> > index 37a9492edb3e..7e532a93835b 100644
> > --- a/tools/perf/util/util.c
> > +++ b/tools/perf/util/util.c
> > @@ -416,3 +416,59 @@ char *perf_exe(char *buf, int len)
> >  	}
> >  	return strcpy(buf, "perf");
> >  }
> > +
> > +static int parse_one_sublevel_option(const char *str,
> > +				     struct sublevel_option *opts)
> > +{
> > +	struct sublevel_option *opt = &opts[0];
> > +	char *vstr, *s = strdup(str);
> > +	int v = 1;
> > +
> > +	vstr = strchr(s, '=');
> > +	if (vstr)
> > +		*vstr++ = 0;
> > +
> > +	while (opt->name) {
> > +		if (!strcmp(s, opt->name))
> > +			break;
> > +		opt++;
> > +	}
> > +
> > +	if (!opt->name) {
> > +		pr_err("Unknown option name '%s'\n", s);
> > +		free(s);
> > +		return -1;
> > +	}
> > +
> > +	if (vstr)
> > +		v = atoi(vstr);
> > +
> > +	*opt->value_ptr = v;
> > +	free(s);
> > +	return 0;
> > +}
> > +
> > +/* parse options like --foo a=<n>,b,c... */
> > +int perf_parse_sublevel_options(const char *str, struct sublevel_option *opts)
> > +{
> > +	char *s = strdup(str);
> > +	char *p = NULL;
> > +	int ret;
> > +
> > +	if (!s)
> > +		return -1;
> > +
> > +	p = strtok(s, ",");
> > +	while (p) {
> > +		ret = parse_one_sublevel_option(p, opts);
> > +		if (ret) {
> > +			free(s);
> > +			return ret;
> > +		}
> > +
> > +		p = strtok(NULL, ",");
> > +	}
> > +
> > +	free(s);
> > +	return 0;
> > +}
> > \ No newline at end of file
> > diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
> > index f486fdd3a538..8cb1f980935c 100644
> > --- a/tools/perf/util/util.h
> > +++ b/tools/perf/util/util.h
> > @@ -52,6 +52,13 @@ void perf_set_multithreaded(void);
> >  
> >  char *perf_exe(char *buf, int len);
> >  
> > +struct sublevel_option {
> > +	const char *name;
> > +	int *value_ptr;
> > +};
> > +
> > +int perf_parse_sublevel_options(const char *str, struct sublevel_option *opts);
> > +
> >  #ifndef O_CLOEXEC
> >  #ifdef __sparc__
> >  #define O_CLOEXEC      0x400000
> > -- 
> > 2.25.1
> > 
> 
> -- 
> 
> - Arnaldo

-- 
Cheers,
Changbin Du