* Defend against incomplete process detection in case of

          threads that are part of a device driver.

src/backends/ocarina-backends-utils.adb

@@ -945,9 +945,8 @@ package body Ocarina.Backends.Utils is
    ---------------------------
 
    function Get_Container_Process (E : Node_Id) return Node_Id is
-   begin
       pragma Assert (Present (E));
-
+   begin
       case Kind (E) is
          when K_Call_Instance =>
             return Get_Container_Process (Parent_Sequence (E));
@@ -965,6 +964,14 @@ package body Ocarina.Backends.Utils is
             elsif Is_Process (E) or else Is_Device (E) then
                return Parent_Subcomponent (E);
 
+            elsif Is_Abstract (E) then
+               --  It is allowed for a thread to be part of an
+               --  abstract component (e.g. a device driver). In this
+               --  case, we cannot retrieve the corresponding process
+               --  instance.
+
+               return No_Node;
+
             else
                raise Program_Error
                  with "Wrong node kind in " &

src/backends/ocarina-backends-utils.ads

@@ -158,7 +158,8 @@ package Ocarina.Backends.Utils is
 
    function Get_Container_Process (E : Node_Id) return Node_Id;
    --  Return the process subcomponent instance that contains the
-   --  subprogram call or thread instance E.
+   --  subprogram call or thread instance E, return No_Node if it
+   --  cannot be determined.
 
    function Get_Container_Thread (E : Node_Id) return Node_Id;
    --  Return the thread subcomponent instance that contains the