iplink_can: code refactoring of print_ctrlmode()

This patch only does cleanup and do not introduce any functional
changes.

We do some code refactoring of print_ctrlmode() in prevision of the
upcoming patch:

  - remove the first argument of print_ctrlmode(). It is a pointer to
    FILE and is never used.

  - add a new function argument: enum output_type t in order to
    specify the output type (i.e. PRINT_{FP,JSON,ANY}).

  - add a new function argument: const char *key in order to specify
    the name of the json array (e.g. "ctrlmode").

  - replace the _PF() macro with the print_flag() function to increase
    readability.

  - directly return if none of the flags are set (previously, this
    check was done before calling the function).

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: David Ahern <dsahern@kernel.org>

diff --git a/ip/iplink_can.c b/ip/iplink_can.c
index 0b2ff8a3f6aff46b29facff7b7e48d8d8b48f2a1..c910365dfaa2344848223ecef754c8d0c41d99b4 100644 (file)
--- a/ip/iplink_can.c
+++ b/ip/iplink_can.c
@@ -88,34 +88,43 @@ static void set_ctrlmode(char *name, char *arg,
        cm->mask |= flags;
 }
 
-static void print_ctrlmode(FILE *f, __u32 cm)
+static void print_flag(enum output_type t, __u32 *flags, __u32 flag,
+                      const char* name)
 {
-       open_json_array(PRINT_ANY, is_json_context() ? "ctrlmode" : "<");
-#define _PF(cmflag, cmname)                                            \
-       if (cm & cmflag) {                                              \
-               cm &= ~cmflag;                                          \
-               print_string(PRINT_ANY, NULL, cm ? "%s," : "%s", cmname); \
+       if (*flags & flag) {
+               *flags &= ~flag;
+               print_string(t, NULL, *flags ? "%s," : "%s", name);
        }
-       _PF(CAN_CTRLMODE_LOOPBACK, "LOOPBACK");
-       _PF(CAN_CTRLMODE_LISTENONLY, "LISTEN-ONLY");
-       _PF(CAN_CTRLMODE_3_SAMPLES, "TRIPLE-SAMPLING");
-       _PF(CAN_CTRLMODE_ONE_SHOT, "ONE-SHOT");
-       _PF(CAN_CTRLMODE_BERR_REPORTING, "BERR-REPORTING");
-       _PF(CAN_CTRLMODE_FD, "FD");
-       _PF(CAN_CTRLMODE_FD_NON_ISO, "FD-NON-ISO");
-       _PF(CAN_CTRLMODE_PRESUME_ACK, "PRESUME-ACK");
-       _PF(CAN_CTRLMODE_CC_LEN8_DLC, "CC-LEN8-DLC");
-#undef _PF
-       if (cm)
-               print_hex(PRINT_ANY, NULL, "%x", cm);
-       close_json_array(PRINT_ANY, "> ");
+}
+
+static void print_ctrlmode(enum output_type t, __u32 flags, const char* key)
+{
+       if (!flags)
+               return;
+
+       open_json_array(t, is_json_context() ? key : "<");
+
+       print_flag(t, &flags, CAN_CTRLMODE_LOOPBACK, "LOOPBACK");
+       print_flag(t, &flags, CAN_CTRLMODE_LISTENONLY, "LISTEN-ONLY");
+       print_flag(t, &flags, CAN_CTRLMODE_3_SAMPLES, "TRIPLE-SAMPLING");
+       print_flag(t, &flags, CAN_CTRLMODE_ONE_SHOT, "ONE-SHOT");
+       print_flag(t, &flags, CAN_CTRLMODE_BERR_REPORTING, "BERR-REPORTING");
+       print_flag(t, &flags, CAN_CTRLMODE_FD, "FD");
+       print_flag(t, &flags, CAN_CTRLMODE_FD_NON_ISO, "FD-NON-ISO");
+       print_flag(t, &flags, CAN_CTRLMODE_PRESUME_ACK, "PRESUME-ACK");
+       print_flag(t, &flags, CAN_CTRLMODE_CC_LEN8_DLC, "CC-LEN8-DLC");
+
+       if (flags)
+               print_hex(t, NULL, "%x", flags);
+
+       close_json_array(t, "> ");
 }
 
 static int can_parse_opt(struct link_util *lu, int argc, char **argv,
                         struct nlmsghdr *n)
 {
        struct can_bittiming bt = {}, dbt = {};
-       struct can_ctrlmode cm = {0, 0};
+       struct can_ctrlmode cm = { 0 };
 
        while (argc > 0) {
                if (matches(*argv, "bitrate") == 0) {
@@ -282,8 +291,7 @@ static void can_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
        if (tb[IFLA_CAN_CTRLMODE]) {
                struct can_ctrlmode *cm = RTA_DATA(tb[IFLA_CAN_CTRLMODE]);
 
-               if (cm->flags)
-                       print_ctrlmode(f, cm->flags);
+               print_ctrlmode(PRINT_ANY, cm->flags, "ctrlmode");
        }
 
        if (tb[IFLA_CAN_STATE]) {