score: Change TOD_LATEST_YEAR to 2099

This simplifies the implementation a bit.  Declare _TOD_Days_to_date[] in
<rtems/score/todimpl.h>.  Make _TOD_Days_per_month[] and
_TOD_Days_since_last_leap_year[] static.

Update #4338.

7 files changed, 58 insertions, 90 deletions

diff --git a/bsps/bfin/shared/dev/rtc.c b/bsps/bfin/shared/dev/rtc.c
index cb15ca0607..e3fb48b4bf 100644
--- a/bsps/bfin/shared/dev/rtc.c
+++ b/bsps/bfin/shared/dev/rtc.c
@@ -22,11 +22,6 @@
 #include <rtems/score/todimpl.h>
 #include <rtems/rtems/clockimpl.h>
 
-/* The following are inside RTEMS -- we are violating visibility!!!
- * Perhaps an API could be defined to get days since 1 Jan.
- */
-extern const uint16_t   _TOD_Days_to_date[2][13];
-
 /*
  *  Prototypes and routines used below
  */
@@ -75,7 +70,7 @@ int setRealTime(
   tod_temp = *tod;
 
   days = (tod_temp.year - TOD_BASE_YEAR) * 365 + \
-          _TOD_Days_to_date[0][tod_temp.month] + tod_temp.day - 1;
+          _TOD_Days_to_date[1][tod_temp.month] + tod_temp.day - 1;
   if (tod_temp.month < 3)
     days +=  Leap_years_until_now (tod_temp.year - 1);
   else
@@ -115,7 +110,7 @@ void getRealTime(
 
   /* finding month and day */
   Leap_year = (((!(tod_temp.year%4)) && (tod_temp.year%100)) ||
-              (!(tod_temp.year%400)))?1:0;
+              (!(tod_temp.year%400)))?0:1;
   for (n=1; n<=12; n++) {
     if (days <= _TOD_Days_to_date[Leap_year][n+1]) {
       tod_temp.month = n;
diff --git a/cpukit/include/rtems/score/todimpl.h b/cpukit/include/rtems/score/todimpl.h
index f85689fd9c..acfec00186 100644
--- a/cpukit/include/rtems/score/todimpl.h
+++ b/cpukit/include/rtems/score/todimpl.h
@@ -142,12 +142,16 @@ extern "C" {
  *  32 bits can accept as latest point in time 2106-Feb-7 6:28:15
  *  but to simplify the implementation, is was decided to only
  *  check that the year is not greater than the year of this constant.
+ *  The year 2099 was chosen because all years evenly divisible by 4 from 1988
+ *  to 2099 are leap years.  In this time frame, years evenly divisible by 100
+ *  are no leap years unless they are evenly divisible by 400.  Thus the year
+ *  2000 is a leap year.
  *
- *  The internal realtime clock can run centuries longer but in
+ *  The internal CLOCK_REALTIME can run centuries longer but in
  *  contrast to the POSIX API, the RTEMS Classic API does not
  *  support this for efficiency reasons.
  */
-#define TOD_LATEST_YEAR 2105
+#define TOD_LATEST_YEAR 2099
 
 /**
  * @addtogroup RTEMSScoreTOD
@@ -176,6 +180,14 @@ typedef struct {
 extern TOD_Control _TOD;
 
 /**
+ * @brief This array contains the number of days in all months up to the month
+ *   indicated by the index of the second dimension.
+ *
+ * The first dimension should be 0 for leap years, and 1 otherwise.
+ */
+extern const uint16_t _TOD_Days_to_date[ 2 ][ 13 ];
+
+/**
  * @brief Locks the time of day mutex.
  */
 void _TOD_Lock( void );
@@ -216,6 +228,21 @@ static inline void _TOD_Release( ISR_lock_Context *lock_context )
 }
 
 /**
+ * @brief Maps the year to the leap year index.
+ *
+ * @param year is the year to map.
+ *
+ * @retval 0 The year is a leap year.
+ *
+ * @retval 1 The year is not a leap year.
+ */
+static inline size_t _TOD_Get_leap_year_index( uint32_t year )
+{
+  _Assert( year % 4 != 0 || year % 100 != 0 || year % 400 == 0 );
+  return ( ( year % 4 ) + 3 ) / 4;
+}
+
+/**
  * @brief Checks the time point is a valid new time of day for _TOD_Set().
  *
  * @param tod the time of day to check.
diff --git a/cpukit/rtems/src/clockgettod.c b/cpukit/rtems/src/clockgettod.c
index dea136d477..5058b42375 100644
--- a/cpukit/rtems/src/clockgettod.c
+++ b/cpukit/rtems/src/clockgettod.c
@@ -32,8 +32,6 @@
 #define RTEMS_DAYS_PER_YEAR   (365UL)
 #define RTEMS_YEAR_BASE       (1970UL)
 
-extern const uint16_t _TOD_Days_to_date[2][13];
-
 static bool _Leap_year(
   uint32_t year
 )
@@ -64,9 +62,9 @@ static uint32_t _Year_day_as_month(
   uint32_t        month = 0;
 
   if ( _Leap_year( year ) )
-    days_to_date = _TOD_Days_to_date[1];
-  else
     days_to_date = _TOD_Days_to_date[0];
+  else
+    days_to_date = _TOD_Days_to_date[1];
 
   days_to_date += 2;
 
diff --git a/cpukit/rtems/src/clocktodtoseconds.c b/cpukit/rtems/src/clocktodtoseconds.c
index 86e89f86eb..43bf6c59c5 100644
--- a/cpukit/rtems/src/clocktodtoseconds.c
+++ b/cpukit/rtems/src/clocktodtoseconds.c
@@ -23,16 +23,9 @@
 #include <rtems/rtems/clockimpl.h>
 #include <rtems/score/todimpl.h>
 
-#define TOD_SECONDS_AT_2100_03_01_00_00 4107542400UL
-
-/*
- *  The following array contains the number of days in all months
- *  up to the month indicated by the index of the second dimension.
- *  The first dimension should be 1 for leap years, and 0 otherwise.
- */
-const uint16_t   _TOD_Days_to_date[2][13] = {
-  { 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 },
-  { 0, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 }
+const uint16_t _TOD_Days_to_date[ 2 ][ 13 ] = {
+  { 0, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335 },
+  { 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }
 };
 
 /*
@@ -48,21 +41,18 @@ Watchdog_Interval   _TOD_To_seconds(
   const rtems_time_of_day *the_tod
 )
 {
-  uint32_t   time;
-  uint32_t   year_mod_4;
+  uint32_t time;
+  size_t   leap_year_index;
 
   time = the_tod->day - 1;
-  year_mod_4 = the_tod->year & 3;
 
-  if ( year_mod_4 == 0 )
-    time += _TOD_Days_to_date[ 1 ][ the_tod->month ];
-  else
-    time += _TOD_Days_to_date[ 0 ][ the_tod->month ];
+  leap_year_index = _TOD_Get_leap_year_index( the_tod->year );
+  time += _TOD_Days_to_date[ leap_year_index ][ the_tod->month ];
 
   time += ( (the_tod->year - TOD_BASE_YEAR) / 4 ) *
             ( (TOD_DAYS_PER_YEAR * 4) + 1);
 
-  time += _TOD_Days_since_last_leap_year[ year_mod_4 ];
+  time += _TOD_Days_since_last_leap_year[ the_tod->year % 4 ];
 
   time *= TOD_SECONDS_PER_DAY;
 
@@ -70,13 +60,6 @@ Watchdog_Interval   _TOD_To_seconds(
              * TOD_SECONDS_PER_MINUTE;
 
   time += the_tod->second;
-
-  /* The year 2100 is not a leap year */
-  if ( time
-      >= (TOD_SECONDS_AT_2100_03_01_00_00 - TOD_SECONDS_1970_THROUGH_1988)) {
-    time -= TOD_SECONDS_PER_DAY;
-  }
-
   time += TOD_SECONDS_1970_THROUGH_1988;
 
   return( time );
diff --git a/cpukit/rtems/src/clocktodvalidate.c b/cpukit/rtems/src/clocktodvalidate.c
index 0e3b5772b5..4433374e65 100644
--- a/cpukit/rtems/src/clocktodvalidate.c
+++ b/cpukit/rtems/src/clocktodvalidate.c
@@ -26,13 +26,13 @@
 
 /*
  *  The following array contains the number of days in all months.
- *  The first dimension should be 1 for leap years, and 0 otherwise.
+ *  The first dimension should be 0 for leap years, and 1 otherwise.
  *  The second dimension should range from 1 to 12 for January to
- *  February, respectively.
+ *  December, respectively.
  */
-const uint32_t   _TOD_Days_per_month[ 2 ][ 13 ] = {
-  { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
-  { 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
+static const uint32_t _TOD_Days_per_month[ 2 ][ 13 ] = {
+  { 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+  { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
 };
 
 rtems_status_code _TOD_Validate(
@@ -40,6 +40,7 @@ rtems_status_code _TOD_Validate(
   TOD_Ticks_validation     ticks_validation
 )
 {
+  size_t  leap_year_index;
   uint32_t days_in_month;
   uint32_t ticks_per_second;
   uint32_t ticks_mask;
@@ -79,11 +80,8 @@ rtems_status_code _TOD_Validate(
     return RTEMS_INVALID_CLOCK;
   }
 
-  if (((the_tod->year % 4) == 0 && (the_tod->year % 100 != 0)) ||
-     (the_tod->year % 400 == 0))
-    days_in_month = _TOD_Days_per_month[ 1 ][ the_tod->month ];
-  else
-    days_in_month = _TOD_Days_per_month[ 0 ][ the_tod->month ];
+  leap_year_index = _TOD_Get_leap_year_index( the_tod->year );
+  days_in_month = _TOD_Days_per_month[ leap_year_index ][ the_tod->month ];
 
   if ( the_tod->day > days_in_month ) {
     return RTEMS_INVALID_CLOCK;
diff --git a/testsuites/sptests/sp2038/init.c b/testsuites/sptests/sp2038/init.c
index dedd66d2c3..02789e55a5 100644
--- a/testsuites/sptests/sp2038/init.c
+++ b/testsuites/sptests/sp2038/init.c
@@ -143,13 +143,7 @@ static const uint32_t sample_seconds [] = {
   3979434495UL,
   4011056895UL,
   4042592895UL,
-  4074128895UL,
-  4105664895UL,
-  4137200895UL,
-  4168736895UL,
-  4200272895UL,
-  4231808895UL,
-  4263431295UL
+  4074128895UL
 };
 
 static const rtems_time_of_day nearly_problem_2038 = {
@@ -179,24 +173,6 @@ static const rtems_time_of_day tod_to_seconds_base = {
   .second = 15
 };
 
-static const rtems_time_of_day nearly_problem_2106 = {
-  .year = 2105,
-  .month = 12,
-  .day = 31,
-  .hour = 23,
-  .minute = 59,
-  .second = 59
-};
-
-static const rtems_time_of_day problem_2106 = {
-  .year = 2106,
-  .month = 1,
-  .day = 1,
-  .hour = 0,
-  .minute = 0,
-  .second = 0
-};
-
 static const rtems_time_of_day problem_2100 = {
   .year = 2100,
   .month = 2,
@@ -242,24 +218,15 @@ static void test_tod_to_seconds(void)
 static void test_problem_year(void)
 {
   rtems_status_code sc = RTEMS_SUCCESSFUL;
-  time_t zero = 0;
-  time_t one = 1;
-  time_t maybe_negative = zero - one;
   bool time_t_is_32_bit = sizeof(time_t) == 4;
-  bool time_t_is_signed = maybe_negative < zero;
 
   if (time_t_is_32_bit) {
     const rtems_time_of_day *nearly_problem = NULL;
     const rtems_time_of_day *problem = NULL;
     rtems_time_of_day now;
 
-    if (time_t_is_signed) {
-      nearly_problem = &nearly_problem_2038;
-      problem = &problem_2038;
-    } else {
-      nearly_problem = &nearly_problem_2106;
-      problem = &problem_2106;
-    }
+    nearly_problem = &nearly_problem_2038;
+    problem = &problem_2038;
 
     sc = rtems_clock_set(nearly_problem);
     ASSERT_SC(sc);
@@ -282,7 +249,7 @@ static void test_leap_year(void)
     const rtems_time_of_day *problem2 = &problem_2100_2;
     // 2100 is not a leap year, so it should have 28 days
     test_status = _TOD_Validate(problem, TOD_ENABLE_TICKS_VALIDATION);
-    rtems_test_assert(test_status == RTEMS_SUCCESSFUL);
+    rtems_test_assert(test_status == RTEMS_INVALID_CLOCK);
     test_status = _TOD_Validate(problem2, TOD_ENABLE_TICKS_VALIDATION);
     rtems_test_assert(test_status == RTEMS_INVALID_CLOCK);
 }
@@ -309,7 +276,7 @@ static void test_every_day(void)
     rtems_status_code sc = RTEMS_SUCCESSFUL;
     rtems_time_of_day now;
 
-    for (every_day.year = 1988; every_day.year <= 2100; ++every_day.year) {
+    for (every_day.year = 1988; every_day.year <= 2099; ++every_day.year) {
         int leap_year = test_year_is_leap_year(every_day.year) ? 1 : 0;
         for (every_day.month = 1; every_day.month <= 12; ++every_day.month) {
             int days = days_per_month[leap_year][every_day.month - 1];
diff --git a/testsuites/sptests/spclock_err02/init.c b/testsuites/sptests/spclock_err02/init.c
index c879c4ce1f..2200b24ec6 100644
--- a/testsuites/sptests/spclock_err02/init.c
+++ b/testsuites/sptests/spclock_err02/init.c
@@ -89,7 +89,7 @@ rtems_task Init(
   directive_failed( status, "rtems_clock_get_tod" );
   print_time( "TA1 - rtems_clock_get_tod - ", &time, " - RTEMS_SUCCESSFUL\n" );
 
-  build_time( &time, 12, 31, 2100, 23, 59, 59, 0 );
+  build_time( &time, 12, 31, 2099, 23, 59, 59, 0 );
   status = rtems_clock_set( &time );
   directive_failed( status, "rtems_clock_set" );
   print_time( "TA1 - rtems_clock_set - ", &time, " - RTEMS_SUCCESSFUL\n" );
@@ -98,10 +98,10 @@ rtems_task Init(
   directive_failed( status, "rtems_clock_set" );
   print_time( "TA1 - rtems_clock_get_tod - ", &time, " - RTEMS_SUCCESSFUL\n" );
 
-  build_time( &time, 12, 31, 2099, 23, 59, 59, 0 );
+  build_time( &time, 1, 1, 2100, 0, 0, 0, 0 );
   status = rtems_clock_set( &time );
-  directive_failed( status, "rtems_clock_set" );
-  print_time( "TA1 - rtems_clock_set - ", &time, " - RTEMS_SUCCESSFUL\n" );
+  fatal_directive_status( status, RTEMS_INVALID_CLOCK, "rtems_clock_set" );
+  print_time( "TA1 - rtems_clock_set - ", &time, " - RTEMS_INVALID_CLOCK\n" );
   status = rtems_task_wake_after( rtems_clock_get_ticks_per_second() );
   status = rtems_clock_get_tod( &time );
   directive_failed( status, "rtems_clock_set" );