libbb: more compact API for bb_parse_mode()

function                                             old     new   delta
make_device                                         2182    2188      +6
parse_command                                       1440    1443      +3
parse_params                                        1497    1499      +2
install_main                                         773     769      -4
mkdir_main                                           168     160      -8
getoptscmd                                           641     632      -9
builtin_umask                                        158     147     -11
bb_parse_mode                                        431     410     -21
umaskcmd                                             286     258     -28
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/6 up/down: 11/-81)            Total: -70 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 7 insertions, 9 deletions

diff --git a/libbb/parse_mode.c b/libbb/parse_mode.c
index 5a4e1c579..bddd39bca 100644
--- a/libbb/parse_mode.c
+++ b/libbb/parse_mode.c
@@ -15,7 +15,7 @@
 
 #define FILEMODEBITS (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
 
-int FAST_FUNC bb_parse_mode(const char *s, mode_t *current_mode)
+int FAST_FUNC bb_parse_mode(const char *s, unsigned current_mode)
 {
         static const mode_t who_mask[] = {
                 S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO, /* a */
@@ -46,13 +46,12 @@ int FAST_FUNC bb_parse_mode(const char *s, mode_t *current_mode)
 
                 tmp = strtoul(s, &e, 8);
                 if (*e || (tmp > 07777U)) { /* Check range and trailing chars. */
-                        return 0;
+                        return -1;
                 }
-                *current_mode = tmp;
-                return 1;
+                return tmp;
         }
 
-        new_mode = *current_mode;
+        new_mode = current_mode;
 
         /* Note: we allow empty clauses, and hence empty modes.
          * We treat an empty mode as no change to perms. */
@@ -71,7 +70,7 @@ int FAST_FUNC bb_parse_mode(const char *s, mode_t *current_mode)
                         if (*p == *s) {
                                 wholist |= who_mask[(int)(p-who_chars)];
                                 if (!*++s) {
-                                        return 0;
+                                        return -1;
                                 }
                                 goto WHO_LIST;
                         }
@@ -80,7 +79,7 @@ int FAST_FUNC bb_parse_mode(const char *s, mode_t *current_mode)
                 do {    /* Process action list. */
                         if ((*s != '+') && (*s != '-')) {
                                 if (*s != '=') {
-                                        return 0;
+                                        return -1;
                                 }
                                 /* Since op is '=', clear all bits corresponding to the
                                  * wholist, or all file bits if wholist is empty. */
@@ -145,6 +144,5 @@ int FAST_FUNC bb_parse_mode(const char *s, mode_t *current_mode)
                 } while (*s && (*s != ','));
         }
 
-        *current_mode = new_mode;
-        return 1;
+        return new_mode;
 }