score: Introduce Thread_Entry_information

This avoids potential dead code in _Thread_Handler().  It gets rid of
the dangerous function pointer casts.

Update #2514.

8 files changed, 104 insertions, 74 deletions

diff --git a/cpukit/score/src/threadcreateidle.c b/cpukit/score/src/threadcreateidle.c
index 8a5812f1a5..e9d12dc963 100644
--- a/cpukit/score/src/threadcreateidle.c
+++ b/cpukit/score/src/threadcreateidle.c
@@ -25,6 +25,14 @@
 
 static void _Thread_Create_idle_for_cpu( Per_CPU_Control *cpu )
 {
+  Thread_Entry_information entry = {
+    .adaptor = _Thread_Entry_adaptor_idle,
+    .Kinds = {
+      .Idle = {
+        .entry = rtems_configuration_get_idle_task()
+      }
+    }
+  };
   Objects_Name    name;
   Thread_Control *idle;
 
@@ -59,14 +67,7 @@ static void _Thread_Create_idle_for_cpu( Per_CPU_Control *cpu )
   cpu->heir      =
   cpu->executing = idle;
 
-  _Thread_Start(
-    idle,
-    THREAD_START_NUMERIC,
-    rtems_configuration_get_idle_task(),
-    NULL,
-    0,
-    cpu
-  );
+  _Thread_Start( idle, &entry, cpu );
 }
 
 void _Thread_Create_idle( void )
diff --git a/cpukit/score/src/threadentryadaptoridle.c b/cpukit/score/src/threadentryadaptoridle.c
new file mode 100644
index 0000000000..e98f562a30
--- /dev/null
+++ b/cpukit/score/src/threadentryadaptoridle.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2015 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/score/threadimpl.h>
+
+void _Thread_Entry_adaptor_idle( Thread_Control *executing )
+{
+  const Thread_Entry_idle *idle = &executing->Start.Entry.Kinds.Idle;
+
+  ( *idle->entry )( 0 );
+}
diff --git a/cpukit/score/src/threadentryadaptornumeric.c b/cpukit/score/src/threadentryadaptornumeric.c
new file mode 100644
index 0000000000..acc06f0614
--- /dev/null
+++ b/cpukit/score/src/threadentryadaptornumeric.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2015 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/score/threadimpl.h>
+
+void _Thread_Entry_adaptor_numeric( Thread_Control *executing )
+{
+  const Thread_Entry_numeric *numeric = &executing->Start.Entry.Kinds.Numeric;
+
+  ( *numeric->entry )( numeric->argument );
+}
diff --git a/cpukit/score/src/threadentryadaptorpointer.c b/cpukit/score/src/threadentryadaptorpointer.c
new file mode 100644
index 0000000000..65866d886f
--- /dev/null
+++ b/cpukit/score/src/threadentryadaptorpointer.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2015 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/score/threadimpl.h>
+
+void _Thread_Entry_adaptor_pointer( Thread_Control *executing )
+{
+  const Thread_Entry_pointer *pointer = &executing->Start.Entry.Kinds.Pointer;
+
+  executing->Wait.return_argument = ( *pointer->entry )( pointer->argument );
+}
diff --git a/cpukit/score/src/threadglobalconstruction.c b/cpukit/score/src/threadglobalconstruction.c
index 56a6df11a9..1e84124c55 100644
--- a/cpukit/score/src/threadglobalconstruction.c
+++ b/cpukit/score/src/threadglobalconstruction.c
@@ -44,10 +44,11 @@
   #define EXECUTE_GLOBAL_CONSTRUCTORS
 #endif
 
-void _Thread_Global_construction( Thread_Entry entry_point )
+void _Thread_Global_construction(
+  Thread_Control                 *executing,
+  const Thread_Entry_information *entry
+)
 {
-  Thread_Control *executing;
-
 #if defined(EXECUTE_GLOBAL_CONSTRUCTORS)
   /*
    *  _init could be a weak symbol and we SHOULD test it but it isn't
@@ -58,17 +59,7 @@ void _Thread_Global_construction( Thread_Entry entry_point )
 #endif
 
   _Thread_Disable_dispatch();
-
-  executing = _Thread_Executing;
-  executing->Start.entry_point = entry_point;
-
-  _Thread_Restart(
-    executing,
-    executing,
-    executing->Start.pointer_argument,
-    executing->Start.numeric_argument
-  );
-
+  _Thread_Restart( executing, executing, entry );
   _Thread_Enable_dispatch();
 
   _Assert_Not_reached();
diff --git a/cpukit/score/src/threadhandler.c b/cpukit/score/src/threadhandler.c
index fd828a2325..2429de57bc 100644
--- a/cpukit/score/src/threadhandler.c
+++ b/cpukit/score/src/threadhandler.c
@@ -90,41 +90,12 @@ void _Thread_Handler( void )
    *  thread/task prototype. The following code supports invoking the
    *  user thread entry point using the prototype expected.
    */
-  if ( executing->Start.prototype == THREAD_START_NUMERIC ) {
-    executing->Wait.return_argument =
-      (*(Thread_Entry_numeric) executing->Start.entry_point)(
-        executing->Start.numeric_argument
-      );
-  }
-  #if defined(RTEMS_POSIX_API)
-    else if ( executing->Start.prototype == THREAD_START_POINTER ) {
-      executing->Wait.return_argument =
-        (*(Thread_Entry_pointer) executing->Start.entry_point)(
-          executing->Start.pointer_argument
-        );
-    }
-  #endif
-  #if defined(FUNCTIONALITY_NOT_CURRENTLY_USED_BY_ANY_API)
-    else if ( executing->Start.prototype == THREAD_START_BOTH_POINTER_FIRST ) {
-      executing->Wait.return_argument =
-         (*(Thread_Entry_both_pointer_first) executing->Start.entry_point)(
-           executing->Start.pointer_argument,
-           executing->Start.numeric_argument
-         );
-    }
-    else if ( executing->Start.prototype == THREAD_START_BOTH_NUMERIC_FIRST ) {
-      executing->Wait.return_argument =
-       (*(Thread_Entry_both_numeric_first) executing->Start.entry_point)(
-         executing->Start.numeric_argument,
-         executing->Start.pointer_argument
-       );
-    }
-  #endif
+  ( *executing->Start.Entry.adaptor )( executing );
 
   /*
-   *  In the switch above, the return code from the user thread body
-   *  was placed in return_argument.  This assumed that if it returned
-   *  anything (which is not supporting in all APIs), then it would be
+   *  In the call above, the return code from the user thread body which return
+   *  something was placed in return_argument.  This assumed that if it
+   *  returned anything (which is not supporting in all APIs), then it would be
    *  able to fit in a (void *).
    */
 
diff --git a/cpukit/score/src/threadrestart.c b/cpukit/score/src/threadrestart.c
index 2b1fef94fc..03b1fba8ff 100644
--- a/cpukit/score/src/threadrestart.c
+++ b/cpukit/score/src/threadrestart.c
@@ -356,15 +356,13 @@ void _Thread_Close( Thread_Control *the_thread, Thread_Control *executing )
 }
 
 bool _Thread_Restart(
-  Thread_Control            *the_thread,
-  Thread_Control            *executing,
-  void                      *pointer_argument,
-  Thread_Entry_numeric_type  numeric_argument
+  Thread_Control                 *the_thread,
+  Thread_Control                 *executing,
+  const Thread_Entry_information *entry
 )
 {
   if ( !_States_Is_dormant( the_thread->current_state ) ) {
-    the_thread->Start.pointer_argument = pointer_argument;
-    the_thread->Start.numeric_argument = numeric_argument;
+    the_thread->Start.Entry = *entry;
 
     _Thread_Request_life_change(
       the_thread,
diff --git a/cpukit/score/src/threadstart.c b/cpukit/score/src/threadstart.c
index dda9495a35..97399ba524 100644
--- a/cpukit/score/src/threadstart.c
+++ b/cpukit/score/src/threadstart.c
@@ -25,22 +25,13 @@
 #include <rtems/score/userextimpl.h>
 
 bool _Thread_Start(
-  Thread_Control            *the_thread,
-  Thread_Start_types         the_prototype,
-  void                      *entry_point,
-  void                      *pointer_argument,
-  Thread_Entry_numeric_type  numeric_argument,
-  Per_CPU_Control           *cpu
+  Thread_Control                 *the_thread,
+  const Thread_Entry_information *entry,
+  Per_CPU_Control                *cpu
 )
 {
   if ( _States_Is_dormant( the_thread->current_state ) ) {
-
-    the_thread->Start.entry_point      = (Thread_Entry) entry_point;
-
-    the_thread->Start.prototype        = the_prototype;
-    the_thread->Start.pointer_argument = pointer_argument;
-    the_thread->Start.numeric_argument = numeric_argument;
-
+    the_thread->Start.Entry = *entry;
     _Thread_Load_environment( the_thread );
 
     if ( cpu == NULL ) {