rtems: Constify rtems_task_wake_when()

Add a parameter to _TOD_Validate() to disable the validation of the
ticks member.

There are two reasons for this change.  Firstly, in
rtems_task_wake_when() was a double check for time_buffer == NULL (one
in rtems_task_wake_when() and one in _TOD_Validate()).  Secondly, the
ticks member is ignored by rtems_task_wake_when().  This was done with a
write of zero to the ticks member and thus a modification of the
user-provided structure.  Now the structure is no longer modified.
Using a mask parameter is quite efficient. You just have to load an
immediate value and there are no additional branches in _TOD_Validate().

Close #4406.

1 files changed, 2 insertions, 6 deletions

diff --git a/cpukit/rtems/src/taskwakewhen.c b/cpukit/rtems/src/taskwakewhen.c
index a25204ad01..4dfa6dfef2 100644
--- a/cpukit/rtems/src/taskwakewhen.c
+++ b/cpukit/rtems/src/taskwakewhen.c
@@ -27,7 +27,7 @@
 #include <rtems/score/watchdogimpl.h>
 
 rtems_status_code rtems_task_wake_when(
-  rtems_time_of_day *time_buffer
+  const rtems_time_of_day *time_buffer
 )
 {
   uint32_t          seconds;
@@ -38,11 +38,7 @@ rtems_status_code rtems_task_wake_when(
   if ( !_TOD_Is_set() )
     return RTEMS_NOT_DEFINED;
 
-  if ( !time_buffer )
-    return RTEMS_INVALID_ADDRESS;
-
-  time_buffer->ticks = 0;
-  status = _TOD_Validate( time_buffer );
+  status = _TOD_Validate( time_buffer, TOD_DISABLE_TICKS_VALIDATION );
 
   if ( status != RTEMS_SUCCESSFUL ) {
     return status;