[PATCH 2/4] score: Add validation that no extensions are null.

[Jennifer Averett]

Verification that rtems_extensions_table did not have null
entries.
---
 cpukit/score/Makefile.am                       |  3 ++-
 cpukit/score/include/rtems/score/userextimpl.h | 14 ++++++++++++++
 cpukit/score/src/userextaddset.c               |  3 +++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/cpukit/score/Makefile.am b/cpukit/score/Makefile.am
index ae92550..6008612 100644
--- a/cpukit/score/Makefile.am
+++ b/cpukit/score/Makefile.am
@@ -327,7 +327,8 @@ libscore_a_SOURCES += src/watchdog.c src/watchdogadjust.c \
 
 ## USEREXT_C_FILES
 libscore_a_SOURCES += src/userextaddset.c \
-    src/userext.c src/userextremoveset.c src/userextiterate.c
+    src/userext.c src/userextremoveset.c src/userextiterate.c \
+    src/userextisvalid.c
 
 ## STD_C_FILES
 libscore_a_SOURCES += src/apiext.c src/chain.c src/chainappend.c \
diff --git a/cpukit/score/include/rtems/score/userextimpl.h b/cpukit/score/include/rtems/score/userextimpl.h
index 04808e1..91c5832 100644
--- a/cpukit/score/include/rtems/score/userextimpl.h
+++ b/cpukit/score/include/rtems/score/userextimpl.h
@@ -77,6 +77,20 @@ void _User_extensions_Remove_set(
 );
 
 /**
+ * @brief User extension is valid
+ *
+ * This method validates that none of the methods
+ * in the extension are NULL.
+ *
+ * @param[in] extension The extension to validate
+ */
+
+bool _User_extensions_Is_valid( 
+  const User_extensions_Table *extension_table
+);
+  
+
+/**
  * @brief User extension visitor.
  *
  * @param[in, out] executing The currently executing thread.
diff --git a/cpukit/score/src/userextaddset.c b/cpukit/score/src/userextaddset.c
index a55dd8c..df04e9c 100644
--- a/cpukit/score/src/userextaddset.c
+++ b/cpukit/score/src/userextaddset.c
@@ -26,6 +26,9 @@ void _User_extensions_Add_set(
   User_extensions_Control *the_extension
 )
 {
+
+  _Assert( !_User_extensions_Is_valid(the_extension) );
+
   _Chain_Append( &_User_extensions_List, &the_extension->Node );
 
   /*
-- 
1.8.1.4