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.

19 files changed, 68 insertions, 43 deletions

diff --git a/src/analyze/analyze-blame.c b/src/analyze/analyze-blame.c
index 6cd6846956..c9112685f8 100644
--- a/src/analyze/analyze-blame.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-calendar.c b/src/analyze/analyze-calendar.c
index 8f6517fa8e..952fe95c2c 100644
--- a/src/analyze/analyze-calendar.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-capability.c b/src/analyze/analyze-capability.c
index ebb205e7f2..8072175a84 100644
--- a/src/analyze/analyze-capability.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-cat-config.c b/src/analyze/analyze-cat-config.c
index 85ed8b01e0..d214ceaf42 100644
--- a/src/analyze/analyze-cat-config.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-condition.c b/src/analyze/analyze-condition.c
index 011066f148..d1643b6180 100644
--- a/src/analyze/analyze-condition.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-critical-chain.c b/src/analyze/analyze-critical-chain.c
index a3d993a373..bb077e2293 100644
--- a/src/analyze/analyze-critical-chain.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-dump.c b/src/analyze/analyze-dump.c
index 24094ce614..448ce09bd7 100644
--- a/src/analyze/analyze-dump.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-exit-status.c b/src/analyze/analyze-exit-status.c
index a3f21c60ea..3a8d3f4b2a 100644
--- a/src/analyze/analyze-exit-status.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-filesystems.c b/src/analyze/analyze-filesystems.c
index 66d8397e31..e30b3a6ac6 100644
--- a/src/analyze/analyze-filesystems.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-log-control.c b/src/analyze/analyze-log-control.c
index d31081b6a0..cead0e833f 100644
--- a/src/analyze/analyze-log-control.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-plot.c b/src/analyze/analyze-plot.c
index edfdfba144..100bdc3787 100644
--- a/src/analyze/analyze-plot.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-service-watchdogs.c b/src/analyze/analyze-service-watchdogs.c
index 96aed32b55..6535eb1a89 100644
--- a/src/analyze/analyze-service-watchdogs.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-syscall-filter.c b/src/analyze/analyze-syscall-filter.c
index 582a043088..308b1724e5 100644
--- a/src/analyze/analyze-syscall-filter.c
+++ b/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
diff --git a/src/analyze/analyze-time.c b/src/analyze/analyze-time.c
index e5744a218e..c233b1f085 100644
--- a/src/analyze/analyze-time.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-timestamp.c b/src/analyze/analyze-timestamp.c
index ddf34ab75f..79764e014e 100644
--- a/src/analyze/analyze-timestamp.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-unit-files.c b/src/analyze/analyze-unit-files.c
index f07ec3e56c..ec9be336e1 100644
--- a/src/analyze/analyze-unit-files.c
+++ b/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;
 }
diff --git a/src/analyze/analyze-unit-paths.c b/src/analyze/analyze-unit-paths.c
index 6fa1527dd6..c2254619bc 100644
--- a/src/analyze/analyze-unit-paths.c
+++ b/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;
 }
diff --git a/src/analyze/analyze.c b/src/analyze/analyze.c
index cb83e73877..2935ecea7a 100644
--- a/src/analyze/analyze.c
+++ b/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);
diff --git a/src/shared/verb-log-control.c b/src/shared/verb-log-control.c
index eea0e8151a..555fb9ff7c 100644
--- a/src/shared/verb-log-control.c
+++ b/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;
 }