Avoid INTERNAL_ERROR_RTEMS_INIT_TASK_ENTRY_IS_NULL

Replace a runtime check with a compile time assertion.  This makes the
INTERNAL_ERROR_RTEMS_INIT_TASK_ENTRY_IS_NULL obsolete.

Update #4181.

3 files changed, 23 insertions, 8 deletions

diff --git a/cpukit/include/rtems/confdefs/inittask.h b/cpukit/include/rtems/confdefs/inittask.h
index a91b9a5917..08eddc0334 100644
--- a/cpukit/include/rtems/confdefs/inittask.h
+++ b/cpukit/include/rtems/confdefs/inittask.h
@@ -100,6 +100,27 @@ extern "C" {
   #define CONFIGURE_INIT_TASK_ARGUMENTS 0
 #endif
 
+/*
+ * Ignore the following warnings from g++ and clang in the static assertion
+ * below:
+ *
+ * warning: the address of 'void Init()' will never be NULL [-Waddress]
+ *
+ * warning: comparison of function 'Init' not equal to a null pointer is always
+ * true [-Wtautological-pointer-compare]
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Waddress"
+#pragma GCC diagnostic ignored "-Wpragmas"
+#pragma GCC diagnostic ignored "-Wtautological-pointer-compare"
+
+RTEMS_STATIC_ASSERT(
+  CONFIGURE_INIT_TASK_ENTRY_POINT != NULL,
+  CONFIGURE_INIT_TASK_ENTRY_POINT_MUST_NOT_BE_NULL
+);
+
+#pragma GCC diagnostic pop
+
 const rtems_initialization_tasks_table _RTEMS_tasks_User_task_table = {
   CONFIGURE_INIT_TASK_NAME,
   CONFIGURE_INIT_TASK_STACK_SIZE,
diff --git a/cpukit/include/rtems/score/interr.h b/cpukit/include/rtems/score/interr.h
index 4b06199ae9..b1f1061c82 100644
--- a/cpukit/include/rtems/score/interr.h
+++ b/cpukit/include/rtems/score/interr.h
@@ -189,7 +189,7 @@ typedef enum {
   INTERNAL_ERROR_NO_MEMORY_FOR_HEAP = 23,
   INTERNAL_ERROR_CPU_ISR_INSTALL_VECTOR = 24,
   INTERNAL_ERROR_RESOURCE_IN_USE = 25,
-  INTERNAL_ERROR_RTEMS_INIT_TASK_ENTRY_IS_NULL = 26,
+  /* INTERNAL_ERROR_RTEMS_INIT_TASK_ENTRY_IS_NULL = 26, */
   /* INTERNAL_ERROR_POSIX_INIT_THREAD_ENTRY_IS_NULL = 27, */
   INTERNAL_ERROR_THREAD_QUEUE_DEADLOCK = 28,
   INTERNAL_ERROR_THREAD_QUEUE_ENQUEUE_STICKY_FROM_BAD_STATE = 29,
diff --git a/cpukit/rtems/src/taskinitusers.c b/cpukit/rtems/src/taskinitusers.c
index 0b23d8bc86..f21c061670 100644
--- a/cpukit/rtems/src/taskinitusers.c
+++ b/cpukit/rtems/src/taskinitusers.c
@@ -29,7 +29,6 @@ void _RTEMS_tasks_Initialize_user_task( void )
   rtems_id                                id;
   rtems_status_code                       return_value;
   const rtems_initialization_tasks_table *user_task;
-  rtems_task_entry                        entry_point;
 
   user_task = &_RTEMS_tasks_User_task_table;
   return_value = rtems_task_create(
@@ -44,14 +43,9 @@ void _RTEMS_tasks_Initialize_user_task( void )
     _Internal_error( INTERNAL_ERROR_RTEMS_INIT_TASK_CREATE_FAILED );
   }
 
-  entry_point = user_task->entry_point;
-  if ( entry_point == NULL ) {
-    _Internal_error( INTERNAL_ERROR_RTEMS_INIT_TASK_ENTRY_IS_NULL );
-  }
-
   return_value = rtems_task_start(
     id,
-    entry_point,
+    user_task->entry_point,
     user_task->argument
   );
   _Assert( rtems_is_status_successful( return_value ) );