perf parse-regs: Split parse_regs

The available registers for --int-regs and --user-regs may be different,
e.g. XMM registers.

Split parse_regs into two dedicated functions for --int-regs and
--user-regs respectively.

Modify the warning message. "--user-regs=?" should be applied to show
the available registers for --user-regs.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1557865174-56264-1-git-send-email-kan.liang@linux.intel.com
[ Changed docs as suggested by Ravi and agreed by Kan ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-record.txt

@@ -406,7 +406,8 @@ symbolic names, e.g. on x86, ax, si. To list the available registers use
 --intr-regs=ax,bx. The list of register is architecture dependent.
 
 --user-regs::
-Capture user registers at sample time. Same arguments as -I.
+Similar to -I, but capture user registers at sample time. To list the available
+user registers use --user-regs=\?.
 
 --running-time::
 Record running and enabled time for read events (:S)

tools/perf/builtin-record.c

@@ -2168,10 +2168,10 @@ static struct option __record_options[] = {
 		    "use per-thread mmaps"),
 	OPT_CALLBACK_OPTARG('I', "intr-regs", &record.opts.sample_intr_regs, NULL, "any register",
 		    "sample selected machine registers on interrupt,"
-		    " use '-I?' to list register names", parse_regs),
+		    " use '-I?' to list register names", parse_intr_regs),
 	OPT_CALLBACK_OPTARG(0, "user-regs", &record.opts.sample_user_regs, NULL, "any register",
 		    "sample selected machine registers on interrupt,"
-		    " use '-I?' to list register names", parse_regs),
+		    " use '--user-regs=?' to list register names", parse_user_regs),
 	OPT_BOOLEAN(0, "running-time", &record.opts.running_time,
 		    "Record running/enabled time of read (:S) events"),
 	OPT_CALLBACK('k', "clockid", &record.opts,

tools/perf/util/parse-regs-options.c

@@ -5,8 +5,8 @@
 #include <subcmd/parse-options.h>
 #include "util/parse-regs-options.h"
 
-int
-parse_regs(const struct option *opt, const char *str, int unset)
+static int
+__parse_regs(const struct option *opt, const char *str, int unset, bool intr)
 {
 	uint64_t *mode = (uint64_t *)opt->value;
 	const struct sample_reg *r;
@@ -48,7 +48,8 @@ parse_regs(const struct option *opt, const char *str, int unset)
 					break;
 			}
 			if (!r->name) {
-				ui__warning("Unknown register \"%s\", check man page or run \"perf record -I?\"\n", s);
+				ui__warning("Unknown register \"%s\", check man page or run \"perf record %s?\"\n",
+					    s, intr ? "-I" : "--user-regs=");
 				goto error;
 			}
 
@@ -69,3 +70,15 @@ parse_regs(const struct option *opt, const char *str, int unset)
 	free(os);
 	return ret;
 }
+
+int
+parse_user_regs(const struct option *opt, const char *str, int unset)
+{
+	return __parse_regs(opt, str, unset, false);
+}
+
+int
+parse_intr_regs(const struct option *opt, const char *str, int unset)
+{
+	return __parse_regs(opt, str, unset, true);
+}

tools/perf/util/parse-regs-options.h

@@ -2,5 +2,6 @@
 #ifndef _PERF_PARSE_REGS_OPTIONS_H
 #define _PERF_PARSE_REGS_OPTIONS_H 1
 struct option;
-int parse_regs(const struct option *opt, const char *str, int unset);
+int parse_user_regs(const struct option *opt, const char *str, int unset);
+int parse_intr_regs(const struct option *opt, const char *str, int unset);
 #endif /* _PERF_PARSE_REGS_OPTIONS_H */