[libc][common] Match the picolibc asctime_r and ctime_r prototypes

picolibc declares the buffer as char[restrict static 26], so the pointer
form warns with -Warray-parameter and the NULL check with -Wnonnull-compare.
Other C libraries keep the pointer form.

Signed-off-by: Parthiban Nallathambi <[email protected]>

1 files changed, 13 insertions, 3 deletions

diff --git a/components/libc/compilers/common/ctime.c b/components/libc/compilers/common/ctime.c
index 77ef7fab34..6ea8aade53 100644
--- a/components/libc/compilers/common/ctime.c
+++ b/components/libc/compilers/common/ctime.c
@@ -26,6 +26,7 @@
  * 2023-09-15     xqyjlj       perf rt_hw_interrupt_disable/enable
  * 2023-10-23     Shell        add lock for _g_timerid
  * 2023-11-16     Shell        Fixup of nanosleep if previous call was interrupted
+ * 2026-11-06     Parthiban    match the picolibc asctime_r/ctime_r prototypes
  */
 
 #include "sys/time.h"
@@ -59,6 +60,15 @@
 
 #define _WARNING_NO_RTC "Cannot find a RTC device!"
 
+/* picolibc declares the buffer as char[restrict static __ASCTIME_SIZE], so it is non-null */
+#if defined(__PICOLIBC__) && defined(__ASCTIME_SIZE)
+#define _ASCTIME_BUF(b)      b[__restrict_arr __min_size(__ASCTIME_SIZE)]
+#define _ASCTIME_BUF_NULL(b) 0
+#else
+#define _ASCTIME_BUF(b)      *b
+#define _ASCTIME_BUF_NULL(b) ((b) == RT_NULL)
+#endif
+
 #if defined(RT_USING_SMART) && defined(RT_USING_VDSO)
 #include <vdso_kernel.h>
 #endif
@@ -255,9 +265,9 @@ time_t mktime(struct tm * const t)
 }
 RTM_EXPORT(mktime);
 
-char* asctime_r(const struct tm *t, char *buf)
+char *asctime_r(const struct tm *t, char _ASCTIME_BUF(buf))
 {
-    if(t == RT_NULL || buf == RT_NULL)
+    if (t == RT_NULL || _ASCTIME_BUF_NULL(buf))
     {
         rt_set_errno(EFAULT);
         return RT_NULL;
@@ -316,7 +326,7 @@ char *asctime(const struct tm *timeptr)
 }
 RTM_EXPORT(asctime);
 
-char *ctime_r(const time_t * tim_p, char * result)
+char *ctime_r(const time_t *tim_p, char _ASCTIME_BUF(result))
 {
     struct tm tm;
     return asctime_r(localtime_r(tim_p, &tm), result);