Re: [PATCH v1 3/4] perf record: add ability to name registers to record

[Jiri Olsa <jolsa@redhat.com>]

On Wed, Aug 19, 2015 at 10:38:25AM +0200, Stephane Eranian wrote:

SNIP

> diff --git a/tools/perf/util/parse-regs-options.c b/tools/perf/util/parse-regs-options.c
> new file mode 100644
> index 0000000..4f2c1c2
> --- /dev/null
> +++ b/tools/perf/util/parse-regs-options.c
> @@ -0,0 +1,71 @@
> +#include "perf.h"
> +#include "util/util.h"
> +#include "util/debug.h"
> +#include "util/parse-options.h"
> +#include "util/parse-regs-options.h"
> +
> +int
> +parse_regs(const struct option *opt, const char *str, int unset)
> +{
> +	uint64_t *mode = (uint64_t *)opt->value;
> +	const struct sample_reg *r;
> +	char *s, *os = NULL, *p;
> +	int ret = -1;
> +
> +	if (unset)
> +		return 0;
> +
> +	/*
> +	 * cannot set it twice
> +	 */
> +	if (*mode)
> +		return -1;
> +
> +	/* str may be NULL in case no arg is passed to -I */
> +	if (str) {
> +		/* because str is read-only */
> +		s = os = strdup(str);
> +		if (!s)
> +			return -1;
> +
> +		for (;;) {
> +			p = strchr(s, ',');
> +			if (p)
> +				*p = '\0';
> +
> +			if (!strcmp(s, "?")) {
> +				fprintf(stderr, "available registers: ");
> +				for (r = sample_reg_masks; r->name; r++) {
> +					fprintf(stderr, "%s ", r->name);
> +				}
> +				fputc('\n', stderr);
> +				/* just printing available regs */
> +				return -1;
> +			}
> +			for (r = sample_reg_masks; r->name; r++) {

the new 'I' is arch dependent, would this fail to link on
other archs besides x86_64 ?  haven't tried though

jirka