selftests: kselftest: Create ksft_print_dbg_msg()

Create ksft_print_dbg_msg() so testers can enable extra debug messages
when running a test with the flag -d.

Signed-off-by: André Almeida <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>

tools/testing/selftests/kselftest.h

···
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdarg.h>
+#include <stdbool.h>
 #include <string.h>
 #include <stdio.h>
 #include <sys/utsname.h>
···
 
 static struct ksft_count ksft_cnt;
 static unsigned int ksft_plan;
+static bool ksft_debug_enabled;
 
 static inline unsigned int ksft_test_num(void)
 {
···
 	printf("# ");
 	errno = saved_errno;
 	vprintf(msg, args);
+	va_end(args);
+}
+
+static inline void ksft_print_dbg_msg(const char *msg, ...)
+{
+	va_list args;
+
+	if (!ksft_debug_enabled)
+		return;
+
+	va_start(args, msg);
+	ksft_print_msg(msg, args);
 	va_end(args);
 }
 

tools/testing/selftests/kselftest_harness.h

···
 {
 	int opt;
 
-	while ((opt = getopt(argc, argv, "hlF:f:V:v:t:T:r:")) != -1) {
+	while ((opt = getopt(argc, argv, "dhlF:f:V:v:t:T:r:")) != -1) {
 		switch (opt) {
 		case 'f':
 		case 'F':
···
 		case 'l':
 			test_harness_list_tests();
 			return KSFT_SKIP;
+		case 'd':
+			ksft_debug_enabled = true;
+			break;
 		case 'h':
 		default:
 			fprintf(stderr,
-				"Usage: %s [-h|-l] [-t|-T|-v|-V|-f|-F|-r name]\n"
+				"Usage: %s [-h|-l|-d] [-t|-T|-v|-V|-f|-F|-r name]\n"
 				"\t-h       print help\n"
 				"\t-l       list all tests\n"
+				"\t-d       enable debug prints\n"
 				"\n"
 				"\t-t name  include test\n"
 				"\t-T name  exclude test\n"
···
 	int opt;
 
 	optind = 1;
-	while ((opt = getopt(argc, argv, "F:f:V:v:t:T:r:")) != -1) {
-		has_positive |= islower(opt);
+	while ((opt = getopt(argc, argv, "dF:f:V:v:t:T:r:")) != -1) {
+		if (opt != 'd')
+			has_positive |= islower(opt);
 
 		switch (tolower(opt)) {
 		case 't':