缩小变量作用域：消除18处variableScope，声明移入实际使用块

App/sys_clock.c

@@ -81,9 +81,7 @@ static uint8_t rtc_calc_week(uint16_t y, uint8_t m, uint8_t d)
  */
 static void unix_to_sd2506(uint32_t unix_secs, sd2506_time_t *p_sd_time)
 {
-    uint32_t y, m, d;
     uint8_t h, mi, s;
-    int is_leap;
 
     /* 时分秒 */
     {
@@ -97,6 +95,8 @@ static void unix_to_sd2506(uint32_t unix_secs, sd2506_time_t *p_sd_time)
 
     /* 年月日 */
     {
+        uint32_t y, m, d;
+        int is_leap;
         uint64_t day_count = ((uint64_t)unix_secs / 86400uL);
 
         y = 1970u;

App/time_sync.c

@@ -36,10 +36,9 @@
 static int time_sync_open_listener(void)
 {
     int retry;
-    int s;
 
     for (retry = 0; retry < 5; retry++) {
-        s = net_socket(NET_AF_INET, NET_SOCK_STREAM);
+        int s = net_socket(NET_AF_INET, NET_SOCK_STREAM);
         if (s < 0) {
             DBG_ERROR("time_sync: net_socket FAIL");
             vTaskDelay(pdMS_TO_TICKS(500));

App/util/ringbuf.c

@@ -91,13 +91,12 @@ size_t ringbuf_peek(const ringbuf_t *rb, uint8_t *data, size_t len)
 {
     size_t n = 0;
     size_t i = 0;
-    size_t idx;
 
     n = ringbuf_avail(rb);
     n = (n < len) ? n : len;
 
     for (i = 0; i < n; i++) {
-        idx = (rb->tail + i) % rb->size;
+        size_t idx = (rb->tail + i) % rb->size;
         data[i] = rb->buf[idx];
     }