Get rid of gcc 7 "fall through" warnings

With gcc 7 we get warnings like the following:

 fdasd.c: In function 'main':
 fdasd.c:3055:4: warning: this statement may fall through
                          [-Wimplicit-fallthrough=]
     fdasd_exit(&anchor, 0);
     ^~~~~~~~~~~~~~~~~~~~~~
 fdasd.c:3056:3: note: here
    default:
    ^~~~~~~

Fix this by marking functions with "__noreturn" to help gcc.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>

fdasd/fdasd.c

@@ -308,7 +308,7 @@ static void fdasd_cleanup(fdasd_anchor_t *anchor)
 /*
  * Exit fdasd.
  */
-static void fdasd_exit(fdasd_anchor_t *anchor, int rc)
+static void __noreturn fdasd_exit(fdasd_anchor_t *anchor, int rc)
 {
 	fdasd_cleanup(anchor);
 	exit(rc);

hyptop/hyptop.c

@@ -348,7 +348,7 @@ void hyptop_text_mode(void)
 /*
  * Exit hyptop
  */
-void hyptop_exit(int rc)
+void __noreturn hyptop_exit(int rc)
 {
 	hyptop_text_mode();
 	exit(rc);

hyptop/hyptop.h

@@ -216,7 +216,7 @@ extern void win_cpu_types_init(void);
  * Misc functions
  */
 extern void hyptop_update_term(void);
-extern void hyptop_exit(int rc);
+extern void __noreturn hyptop_exit(int rc);
 extern void hyptop_text_mode(void);
 
 #endif /* HYPTOP_H */

ipl_tools/cmd_chreipl.c

@@ -97,7 +97,7 @@ static struct locals {
 	enum reipl_type		reipl_type;	/* CCW, FCP, NSS */
 } l;
 
-static void print_usage_chreipl_exit(void)
+static void __noreturn print_usage_chreipl_exit(void)
 {
 	printf(usage_chreipl, g.prog_name);
 	exit(0);

ipl_tools/cmd_chshut.c

@@ -34,7 +34,7 @@ static const char *const usage_chshut =
 "  -h, --help        Print this help, then exit\n"
 "  -v, --version     Print version information, then exit\n";
 
-static void print_usage_chshut_exit(void)
+static void __noreturn print_usage_chshut_exit(void)
 {
 	printf(usage_chshut, g.prog_name);
 	exit(0);

ipl_tools/cmd_lsreipl.c

@@ -25,7 +25,7 @@ static const char *const usage_lsreipl =
 "  -h, --help           Print this help, then exit\n"
 "  -v, --version        Print version information, then exit\n";
 
-static void print_usage_lsreipl_exit(void)
+static void __noreturn print_usage_lsreipl_exit(void)
 {
 	printf(usage_lsreipl, g.prog_name);
 	exit(0);

ipl_tools/cmd_lsshut.c

@@ -20,7 +20,7 @@ static const char *const usage_lsshut =
 "  -h, --help           Print this help, then exit\n"
 "  -v, --version        Print version information, then exit\n";
 
-static void print_usage_lsshut_exit(void)
+static __noreturn void print_usage_lsshut_exit(void)
 {
 	printf(usage_lsshut, g.prog_name);
 	exit(0);

ipl_tools/ipl_tools.h

@@ -24,6 +24,8 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <lib/zt_common.h>
+
 #define IPL_TYPE_LEN_MAX	100
 #define NSS_NAME_LEN_MAX	8
 
@@ -57,8 +59,8 @@ extern void read_str(char *string, const char *file, size_t len);
 extern void read_fw_str(char *string, const char *file, size_t len);
 extern void print_fw_str(const char *fmt, const char *dir, const char *file);
 
-extern void print_version_exit(void);
-extern void print_help_hint_exit(void);
+extern void __noreturn print_version_exit(void);
+extern void __noreturn print_help_hint_exit(void);
 
 /*
  * FCP

ipl_tools/main.c

@@ -14,14 +14,14 @@
 
 struct globals g;
 
-void print_help_hint_exit(void)
+void __noreturn print_help_hint_exit(void)
 {
 	fprintf(stderr, "Try '%s' --help' for more information.\n",
 		g.prog_name);
 	exit(1);
 }
 
-void print_version_exit(void)
+void __noreturn print_version_exit(void)
 {
 	printf("%s: Linux on System z shutdown actions version %s\n",
 		g.prog_name, RELEASE_STRING);

iucvterm/src/getopt.c

@@ -71,8 +71,8 @@ static const struct tool_info iucv_tool[2] = {
 };
 
 
-static void usage_exit(const struct tool_info *prg, int is_error,
-			const char *msg)
+static void __noreturn usage_exit(const struct tool_info *prg, int is_error,
+				  const char *msg)
 {
 	if (msg != NULL)
 		fprintf(stderr, _("%s: %s\n"), prg->name, msg);
@@ -80,7 +80,7 @@ static void usage_exit(const struct tool_info *prg, int is_error,
 	exit(is_error ? 1 : 0);	/* rc=1 .. invalid args */
 }
 
-static void version_exit(const struct tool_info *prg)
+static void __noreturn version_exit(const struct tool_info *prg)
 {
 	printf(_("%s: IUCV Terminal Applications, version %s\n"),
 		prg->name, RELEASE_STRING);

iucvterm/src/ttyrun.c

@@ -62,13 +62,13 @@ static const char usage[] =
 "-h, --help           Displays this help, then exits.\n"
 "-v, --version        Displays version information, then exits.\n";
 
-static void help_exit(const char *prg)
+static void __noreturn help_exit(const char *prg)
 {
 	printf(usage, prg, prg);
 	exit(EXIT_SUCCESS);
 }
 
-static void version_exit(const char *prg)
+static void __noreturn version_exit(const char *prg)
 {
 	printf("%s: Start a program if a terminal device is available, "
 	       "version %s\n", prg, RELEASE_STRING);

zdump/opts.c

@@ -75,7 +75,7 @@ static void init_defaults(void)
 /*
  * Print "help" hint
  */
-static void print_usage_exit(void)
+static void __noreturn print_usage_exit(void)
 {
 	STDERR("Try '%s --help' for more information.\n", g.prog_name);
 	zg_exit(1);
@@ -84,7 +84,7 @@ static void print_usage_exit(void)
 /*
  * Print help text
  */
-static void print_help_exit(void)
+static void __noreturn print_help_exit(void)
 {
 	STDOUT("%s", help_text);
 	zg_exit(0);
@@ -93,7 +93,7 @@ static void print_help_exit(void)
 /*
  * Print version information
  */
-static void print_version_exit(void)
+static void __noreturn print_version_exit(void)
 {
 	STDOUT("%s: Tool for copying and converting dumps version %s\n",
 	       g.prog_name, RELEASE_STRING);