a bugfix for mail queue and printf clipping switch

1. add TOS_CFG_LIBC_PRINTF_EN
1: enable printf to implement tos_kprintf
when you call tos_kprintf(actually currently it's a MACRO rather than a function) , the libc will be invloved into the image, most of the time it means a larger image size.

0: disable printf, means tos_kprintf is defined as an empty MACRO
most of the time, means you will not get a log output from the uart(currently we donnot have a console yet) but a smaller image size.

2. fix a bug of tos_mail_q and tos_priority_mail_q
if we are post-ing a mail and there is[are] task[s] just pend-ing for the mail queue, the mail delivered to the pend-er will be a pointer, and probably it's a pointer to the local variable on the stack. Actually we should do a memcpy rather than a pointer assignment. for more details, see the patch.

kernel/core/include/tos.h

@@ -32,7 +32,6 @@
 #include <tos_fault.h>
 #include <tos_klib.h>
 #include <tos_list.h>
-#include <tos_pm.h>
 #include <tos_pend.h>
 #include <tos_sys.h>
 #include <tos_ring_queue.h>

kernel/core/include/tos_config_default.h

@@ -230,6 +230,10 @@
 #define  TOS_CFG_OBJECT_VERIFY_EN               0u
 #endif
 
+#ifndef TOS_CFG_LIBC_PRINTF_EN
+#define  TOS_CFG_LIBC_PRINTF_EN                     1u // we enable this by default
+#endif
+
 #if     (TOS_CFG_TIMER_AS_PROC == 0u) && !defined(TOS_CFG_TIMER_TASK_PRIO)
 #define  TOS_CFG_TIMER_TASK_PRIO            (k_prio_t)(K_TASK_PRIO_IDLE - (k_prio_t)1u)
 #endif

kernel/core/include/tos_klib.h

@@ -31,14 +31,14 @@
 
 #define TOS_PTR_SANITY_CHECK(ptr) \
     do {    \
-        if (unlikely((ptr) == K_NULL)) {    \
+        if (unlikely(!(ptr))) {    \
             return K_ERR_OBJ_PTR_NULL;    \
         }   \
     } while(0)
 
 #define TOS_PTR_SANITY_CHECK_RC(ptr, return_code) \
     do {    \
-        if (unlikely((ptr) == K_NULL)) {    \
+        if (unlikely(!(ptr))) {    \
             return return_code;    \
         }   \
     } while(0)
@@ -70,12 +70,18 @@
 #define TOS_OBJ_VERIFY_RC(obj, obj_type, return_code)
 #endif
 
+#if TOS_CFG_LIBC_PRINTF_EN > 0u
+#define LIBC_PRINTF             printf
+#else
+#define LIBC_PRINTF(...)
+#endif
+
 // currently we use default microlib supplied by mdk
-#define tos_kprintf(...)         printf(__VA_ARGS__);
+#define tos_kprintf(...)         LIBC_PRINTF(__VA_ARGS__);
 
 #define tos_kprintln(...)   \
-    printf(__VA_ARGS__); \
-    printf("\n");
+    LIBC_PRINTF(__VA_ARGS__); \
+    LIBC_PRINTF("\n");
 
 #define TOS_ASSERT_AUX(exp, function, line) \
     if (!(exp)) { \

kernel/core/include/tos_task.h

@@ -416,8 +416,9 @@ __KERNEL__ __STATIC_INLINE__ void task_state_set_sleeping(k_task_t *task)
 
 __DEBUG__ __STATIC_INLINE__ void task_default_walker(k_task_t *task)
 {
-    char *state_str;
+    char *state_str = "ABNORMAL";
 
+    state_str = state_str;
     tos_kprintln("tsk name: %s", task->name);
 
     if (task->state == K_TASK_STATE_PENDTIMEOUT_SUSPENDED) {

kernel/core/include/tos_tick.h

@@ -32,7 +32,7 @@ __API__ void    tos_tick_handler(void);
 
 __KERNEL__ void         tick_update(k_tick_t tick);
 
-__KERNEL__ k_err_t      tick_list_add(k_task_t *task, k_tick_t timeout);
+__KERNEL__ void         tick_list_add(k_task_t *task, k_tick_t timeout);
 
 __KERNEL__ void         tick_list_remove(k_task_t *task);