[xen master] xentrace: adjust exit code for --help option

[patchbot@xxxxxxx]

commit a40c3aa126ac5956ef2de266dc52d048e26ae576
Author:     Olaf Hering <olaf@xxxxxxxxx>
AuthorDate: Fri May 26 14:38:10 2023 +0200
Commit:     George Dunlap <george.dunlap@xxxxxxxxx>
CommitDate: Fri Jul 28 21:51:27 2023 +0100

    xentrace: adjust exit code for --help option
    
    Invoking the --help option of any tool should not return with an error,
    if that tool does have a documented and implemented help option.
    
    Adjust the usage() function to exit with either error or success.
    Handle the existing entry in the option table to call usage accordingly.
    
    Adjust the getopt value for help. The char '?' is returned for unknown
    options. Returning 'h' instead of '?' allows to handle --help.
    
    Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>
    Reviewed-by: George Dunlap <george.dunlap@xxxxxxxxx>
---
 tools/xentrace/xentrace.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/tools/xentrace/xentrace.c b/tools/xentrace/xentrace.c
index 3548255123..be6226f088 100644
--- a/tools/xentrace/xentrace.c
+++ b/tools/xentrace/xentrace.c
@@ -807,7 +807,7 @@ static void monitor_tbufs(void)
 const char *program_version     = "xentrace v1.2";
 const char *program_bug_address = "<mark.a.williamson@xxxxxxxxx>";
 
-static void usage(void)
+static void usage(int status)
 {
 #define USAGE_STR \
 "Usage: xentrace [OPTION...] [output file]\n" \
@@ -854,7 +854,7 @@ static void usage(void)
     printf(USAGE_STR);
     printf("\nReport bugs to %s\n", program_bug_address);
 
-    exit(EXIT_FAILURE);
+    exit(status);
 }
 
 /* convert the argument string pointed to by arg to a long int representation,
@@ -873,7 +873,7 @@ long sargtol(const char *restrict arg, int base)
     {
         fprintf(stderr, "Invalid option argument: %s\n", arg);
         fprintf(stderr, "Error: %s\n\n", strerror(errno));
-        usage();
+        usage(EXIT_FAILURE);
     }
     else if (endp == arg)
     {
@@ -901,7 +901,7 @@ long sargtol(const char *restrict arg, int base)
 
 invalid:
     fprintf(stderr, "Invalid option argument: %s\n\n", arg);
-    usage();
+    usage(EXIT_FAILURE);
     return 0; /* not actually reached */
 }
 
@@ -917,10 +917,10 @@ static long argtol(const char *restrict arg, int base)
     if (errno != 0) {
         fprintf(stderr, "Invalid option argument: %s\n", arg);
         fprintf(stderr, "Error: %s\n\n", strerror(errno));
-        usage();
+        usage(EXIT_FAILURE);
     } else if (endp == arg || *endp != '\0') {
         fprintf(stderr, "Invalid option argument: %s\n\n", arg);
-        usage();
+        usage(EXIT_FAILURE);
     }
 
     return val;
@@ -1090,7 +1090,7 @@ static void parse_args(int argc, char **argv)
         { "discard-buffers", no_argument,      0, 'D' },
         { "dont-disable-tracing", no_argument, 0, 'x' },
         { "start-disabled", no_argument,       0, 'X' },
-        { "help",           no_argument,       0, '?' },
+        { "help",           no_argument,       0, 'h' },
         { "version",        no_argument,       0, 'V' },
         { 0, 0, 0, 0 }
     };
@@ -1144,8 +1144,12 @@ static void parse_args(int argc, char **argv)
             opts.memory_buffer = sargtol(optarg, 0);
             break;
 
+        case 'h':
+            usage(EXIT_SUCCESS);
+            break;
+
         default:
-            usage();
+            usage(EXIT_FAILURE);
         }
     }
 
--
generated by git-patchbot for /home/xen/git/xen.git#master