[PATCH v3 03/20] tools/x86/kcpuid: Simplify usage() handling

["Ahmed S. Darwish" <darwi@linutronix.de>]

Refactor usage() to accept an exit code parameter and exit the program
after usage output.  This streamlines its callers' code paths.

Remove the "Invalid option" error message since getopt_long(3) already
emits a similar message by default.

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
---
 tools/arch/x86/kcpuid/kcpuid.c | 37 +++++++++++++++-------------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/tools/arch/x86/kcpuid/kcpuid.c b/tools/arch/x86/kcpuid/kcpuid.c
index 8585c1009c8b..b760c5730c89 100644
--- a/tools/arch/x86/kcpuid/kcpuid.c
+++ b/tools/arch/x86/kcpuid/kcpuid.c
@@ -10,6 +10,7 @@
 
 #define ARRAY_SIZE(x)	(sizeof(x) / sizeof((x)[0]))
 #define min(a, b)	(((a) < (b)) ? (a) : (b))
+#define __noreturn	__attribute__((__noreturn__))
 
 typedef unsigned int u32;
 typedef unsigned long long u64;
@@ -584,17 +585,17 @@ static void setup_platform_cpuid(void)
 	leafs_ext = setup_cpuid_range(0x80000000);
 }
 
-static void usage(void)
+static void __noreturn usage(int exit_code)
 {
-	warnx("kcpuid [-abdfhr] [-l leaf] [-s subleaf]\n"
-	      "\t-a|--all             Show both bit flags and complex bit fields info\n"
-	      "\t-b|--bitflags        Show boolean flags only\n"
-	      "\t-d|--detail          Show details of the flag/fields (default)\n"
-	      "\t-f|--flags           Specify the cpuid csv file\n"
-	      "\t-h|--help            Show usage info\n"
-	      "\t-l|--leaf=index      Specify the leaf you want to check\n"
-	      "\t-r|--raw             Show raw cpuid data\n"
-	      "\t-s|--subleaf=sub     Specify the subleaf you want to check"
+	errx(exit_code, "kcpuid [-abdfhr] [-l leaf] [-s subleaf]\n"
+	     "\t-a|--all             Show both bit flags and complex bit fields info\n"
+	     "\t-b|--bitflags        Show boolean flags only\n"
+	     "\t-d|--detail          Show details of the flag/fields (default)\n"
+	     "\t-f|--flags           Specify the cpuid csv file\n"
+	     "\t-h|--help            Show usage info\n"
+	     "\t-l|--leaf=index      Specify the leaf you want to check\n"
+	     "\t-r|--raw             Show raw cpuid data\n"
+	     "\t-s|--subleaf=sub     Specify the subleaf you want to check"
 	);
 }
 
@@ -610,7 +611,7 @@ static struct option opts[] = {
 	{ NULL, 0, NULL, 0 }
 };
 
-static int parse_options(int argc, char *argv[])
+static void parse_options(int argc, char *argv[])
 {
 	int c;
 
@@ -630,9 +631,7 @@ static int parse_options(int argc, char *argv[])
 			user_csv = optarg;
 			break;
 		case 'h':
-			usage();
-			exit(1);
-			break;
+			usage(EXIT_SUCCESS);
 		case 'l':
 			/* main leaf */
 			user_index = strtoul(optarg, NULL, 0);
@@ -645,11 +644,8 @@ static int parse_options(int argc, char *argv[])
 			user_sub = strtoul(optarg, NULL, 0);
 			break;
 		default:
-			warnx("Invalid option '%c'", optopt);
-			return -1;
-	}
-
-	return 0;
+			usage(EXIT_FAILURE);
+		}
 }
 
 /*
@@ -662,8 +658,7 @@ static int parse_options(int argc, char *argv[])
  */
 int main(int argc, char *argv[])
 {
-	if (parse_options(argc, argv))
-		return -1;
+	parse_options(argc, argv);
 
 	/* Setup the cpuid leafs of current platform */
 	setup_platform_cpuid();
-- 
2.48.1