Use negative_errno() to assert errno is positive after a few system calls

This is not particularly intrusive because it happens in simple
utility functions. It helps gcc understand that error codes
are negative.

This gets a rid of most of the remaining warnings.

3 files changed, 5 insertions, 3 deletions

diff --git a/src/basic/btrfs-util.c b/src/basic/btrfs-util.c
index acd48f6954..d07d1df5a8 100644
--- a/src/basic/btrfs-util.c
+++ b/src/basic/btrfs-util.c
@@ -2051,7 +2051,7 @@ int btrfs_subvol_get_parent(int fd, uint64_t subvol_id, uint64_t *ret) {
 
                 args.key.nr_items = 256;
                 if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
-                        return -errno;
+                        return negative_errno();
 
                 if (args.key.nr_items <= 0)
                         break;
diff --git a/src/basic/clock-util.c b/src/basic/clock-util.c
index 00f549c023..05788a360e 100644
--- a/src/basic/clock-util.c
+++ b/src/basic/clock-util.c
@@ -33,6 +33,7 @@
 #include "fd-util.h"
 #include "macro.h"
 #include "string-util.h"
+#include "util.h"
 
 int clock_get_hwclock(struct tm *tm) {
         _cleanup_close_ int fd = -1;
@@ -121,7 +122,8 @@ int clock_set_timezone(int *min) {
          * have read from the RTC.
          */
         if (settimeofday(tv_null, &tz) < 0)
-                return -errno;
+                return negative_errno();
+
         if (min)
                 *min = minutesdelta;
         return 0;
diff --git a/src/basic/path-util.c b/src/basic/path-util.c
index 61fab0e087..4837bb2d7d 100644
--- a/src/basic/path-util.c
+++ b/src/basic/path-util.c
@@ -102,7 +102,7 @@ int path_make_absolute_cwd(const char *p, char **ret) {
 
                 cwd = get_current_dir_name();
                 if (!cwd)
-                        return -errno;
+                        return negative_errno();
 
                 c = strjoin(cwd, "/", p, NULL);
         }