lib/time/day_to_str.[ch]: day_to_str(): Accept a day instead of a dat…

…e, and rename function

It was always being called with 'day * DAY', so do that internally and
simplify.  This grabs some code from print_day_as_date().

Cc: Tobias Stoeckmann <[email protected]>
Signed-off-by: Alejandro Colomar <[email protected]>

lib/time/day_to_str.c

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: 2021-2024, Alejandro Colomar <[email protected]>
+// SPDX-FileCopyrightText: 2024, Tobias Stoeckmann <[email protected]>
 // SPDX-License-Identifier: BSD-3-Clause
 
 
@@ -7,4 +8,4 @@
 #include "time/day_to_str.h"
 
 
-extern inline void date_to_str(size_t size, char buf[size], long date);
+extern inline void day_to_str(size_t size, char buf[size], long day);

lib/time/day_to_str.h

@@ -1,7 +1,6 @@
-/*
- * SPDX-FileCopyrightText: 2021-2023, Alejandro Colomar <[email protected]>
- * SPDX-License-Identifier: BSD-3-Clause
- */
+// SPDX-FileCopyrightText: 2021-2024, Alejandro Colomar <[email protected]>
+// SPDX-FileCopyrightText: 2024, Tobias Stoeckmann <[email protected]>
+// SPDX-License-Identifier: BSD-3-Clause
 
 
 #ifndef SHADOW_INCLUDE_LIB_TIME_DAY_TO_STR_H_
@@ -17,32 +16,36 @@
 #include "string/strtcpy.h"
 
 
-#define DAY_TO_STR(str, day) date_to_str(NITEMS(str), str, day * DAY)
+#define DAY_TO_STR(str, day) day_to_str(NITEMS(str), str, day)
 
 
-inline void date_to_str(size_t size, char buf[size], long date);
+inline void day_to_str(size_t size, char buf[size], long day);
 
 
 inline void
-date_to_str(size_t size, char buf[size], long date)
+day_to_str(size_t size, char buf[size], long day)
 {
- time_t t;
+ time_t date;
  const struct tm *tm;
 
- t = date;
- if (date < 0) {
- (void) strtcpy(buf, "never", size);
+ if (day < 0) {
+ strtcpy(buf, "never", size);
  return;
  }
 
- tm = gmtime(&t);
+ if (__builtin_mul_overflow(day, DAY, &date)) {
+ strtcpy(buf, "future", size);
+ return;
+ }
+
+ tm = gmtime(&date);
  if (tm == NULL) {
- (void) strtcpy(buf, "future", size);
+ strtcpy(buf, "future", size);
  return;
  }
 
  if (strftime(buf, size, "%Y-%m-%d", tm) == 0)
- (void) strtcpy(buf, "future", size);
+ strtcpy(buf, "future", size);
 }