analyze: allow verbs to return positive failure

No functional change is intended. The verbs where it wasn't immediately
clear if the success exit status is 0 or >= 0 are changed to explicitly
return 0. (I think it's better to be explicit than to rely on some call
stack always returning 0 on success.)

Some other functions are cleaned up to be more idiomatic.

src/analyze/analyze-blame.c

@@ -61,5 +61,9 @@ int verb_blame(int argc, char *argv[], void *userdata) {
 
         pager_open(arg_pager_flags);
 
-        return table_print(table, NULL);
+        r = table_print(table, NULL);
+        if (r < 0)
+                return r;
+
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-calendar.c

@@ -123,7 +123,7 @@ static int test_calendar_one(usec_t n, const char *p) {
 }
 
 int verb_calendar(int argc, char *argv[], void *userdata) {
-        int ret = 0, r;
+        int r = 0;
         usec_t n;
 
         if (arg_base_time != USEC_INFINITY)
@@ -132,13 +132,15 @@ int verb_calendar(int argc, char *argv[], void *userdata) {
                 n = now(CLOCK_REALTIME); /* We want to use the same "base" for all expressions */
 
         STRV_FOREACH(p, strv_skip(argv, 1)) {
-                r = test_calendar_one(n, *p);
-                if (ret == 0 && r < 0)
-                        ret = r;
+                int k;
 
-                if (*(p + 1))
+                k = test_calendar_one(n, *p);
+                if (r == 0 && k < 0)
+                        r = k;
+
+                if (p[1])
                         putchar('\n');
         }
 
-        return ret;
+        return r;
 }

src/analyze/analyze-capability.c

@@ -48,5 +48,9 @@ int verb_capabilities(int argc, char *argv[], void *userdata) {
 
         pager_open(arg_pager_flags);
 
-        return table_print(table, NULL);
+        r = table_print(table, NULL);
+        if (r < 0)
+                return r;
+
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-cat-config.c

@@ -42,5 +42,5 @@ int verb_cat_config(int argc, char *argv[], void *userdata) {
                         return r;
         }
 
-        return 0;
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-condition.c

@@ -137,5 +137,11 @@ static int verify_conditions(char **lines, LookupScope scope, const char *unit,
 }
 
 int verb_condition(int argc, char *argv[], void *userdata) {
-        return verify_conditions(strv_skip(argv, 1), arg_scope, arg_unit, arg_root);
+        int r;
+
+        r = verify_conditions(strv_skip(argv, 1), arg_scope, arg_unit, arg_root);
+        if (r < 0)
+                return r;
+
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-critical-chain.c

@@ -226,5 +226,5 @@ int verb_critical_chain(int argc, char *argv[], void *userdata) {
         else
                 list_dependencies(bus, SPECIAL_DEFAULT_TARGET);
 
-        return 0;
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-dump.c

@@ -60,5 +60,9 @@ int verb_dump(int argc, char *argv[], void *userdata) {
                 return bus_log_parse_error(r);
 
         fflush(stdout);
-        return copy_bytes(fd, STDOUT_FILENO, UINT64_MAX, 0);
+        r = copy_bytes(fd, STDOUT_FILENO, UINT64_MAX, 0);
+        if (r < 0)
+                return r;
+
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-exit-status.c

@@ -48,5 +48,9 @@ int verb_exit_status(int argc, char *argv[], void *userdata) {
 
         pager_open(arg_pager_flags);
 
-        return table_print(table, NULL);
+        r = table_print(table, NULL);
+        if (r < 0)
+                return r;
+
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-filesystems.c

@@ -221,5 +221,5 @@ int verb_filesystems(int argc, char *argv[], void *userdata) {
                         first = false;
                 }
 
-        return 0;
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-log-control.c

@@ -14,5 +14,9 @@ int verb_log_control(int argc, char *argv[], void *userdata) {
         if (r < 0)
                 return bus_log_connect_error(r, arg_transport);
 
-        return verb_log_control_common(bus, "org.freedesktop.systemd1", argv[0], argc == 2 ? argv[1] : NULL);
+        r = verb_log_control_common(bus, "org.freedesktop.systemd1", argv[0], argc == 2 ? argv[1] : NULL);
+        if (r < 0)
+                return r;
+
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-plot.c

@@ -391,5 +391,5 @@ int verb_plot(int argc, char *argv[], void *userdata) {
 
         svg("</svg>\n");
 
-        return 0;
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-service-watchdogs.c

@@ -37,5 +37,5 @@ int verb_service_watchdogs(int argc, char *argv[], void *userdata) {
                         return log_error_errno(r, "Failed to set service-watchdog state: %s", bus_error_message(&error, r));
         }
 
-        return 0;
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-syscall-filter.c

@@ -176,7 +176,7 @@ int verb_syscall_filters(int argc, char *argv[], void *userdata) {
                         first = false;
                 }
 
-        return 0;
+        return EXIT_SUCCESS;
 }
 
 #else

src/analyze/analyze-time.c

@@ -18,5 +18,5 @@ int verb_time(int argc, char *argv[], void *userdata) {
                 return r;
 
         puts(buf);
-        return 0;
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-timestamp.c

@@ -79,16 +79,18 @@ static int test_timestamp_one(const char *p) {
 }
 
 int verb_timestamp(int argc, char *argv[], void *userdata) {
-        int ret = 0, r;
+        int r = 0;
 
         STRV_FOREACH(p, strv_skip(argv, 1)) {
-                r = test_timestamp_one(*p);
-                if (ret == 0 && r < 0)
-                        ret = r;
+                int k;
 
-                if (*(p + 1))
+                k = test_timestamp_one(*p);
+                if (r == 0 && k < 0)
+                        r = k;
+
+                if (p[1])
                         putchar('\n');
         }
 
-        return ret;
+        return r;
 }

src/analyze/analyze-unit-files.c

@@ -46,5 +46,5 @@ int verb_unit_files(int argc, char *argv[], void *userdata) {
                 printf("aliases: %s ← %s\n", k, j);
         }
 
-        return 0;
+        return EXIT_SUCCESS;
 }

src/analyze/analyze-unit-paths.c

@@ -16,5 +16,5 @@ int verb_unit_paths(int argc, char *argv[], void *userdata) {
         STRV_FOREACH(p, paths.search_path)
                 puts(*p);
 
-        return 0;
+        return EXIT_SUCCESS;
 }

src/analyze/analyze.c

@@ -607,4 +607,4 @@ static int run(int argc, char *argv[]) {
         return dispatch_verb(argc, argv, verbs, NULL);
 }
 
-DEFINE_MAIN_FUNCTION(run);
+DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE(run);

src/shared/verb-log-control.c

@@ -30,27 +30,22 @@ int verb_log_control_common(sd_bus *bus, const char *destination, const char *ve
                 r = bus_set_property(bus, &bloc,
                                      level ? "LogLevel" : "LogTarget",
                                      &error, "s", value);
-                if (r >= 0)
-                        return 0;
-
-                log_error_errno(r, "Failed to set log %s of %s to %s: %s",
-                                level ? "level" : "target",
-                                bloc.destination, value, bus_error_message(&error, r));
+                if (r < 0)
+                        return log_error_errno(r, "Failed to set log %s of %s to %s: %s",
+                                               level ? "level" : "target",
+                                               bloc.destination, value, bus_error_message(&error, r));
         } else {
                 _cleanup_free_ char *t = NULL;
 
                 r = bus_get_property_string(bus, &bloc,
                                             level ? "LogLevel" : "LogTarget",
                                             &error, &t);
-                if (r >= 0) {
-                        puts(t);
-                        return 0;
-                }
-
-                log_error_errno(r, "Failed to get log %s of %s: %s",
-                                level ? "level" : "target",
-                                bloc.destination, bus_error_message(&error, r));
+                if (r < 0)
+                        return log_error_errno(r, "Failed to get log %s of %s: %s",
+                                               level ? "level" : "target",
+                                               bloc.destination, bus_error_message(&error, r));
+                puts(t);
         }
 
-        return r;
+        return 0;
 }