sc_event::none - an event that is never notified

This commit adds a new static member `const sc_event none`
to the `sc_event` class, which can be used in contexts
where an event is required, which is never notified.

Current use cases in the kernel are:
 * sc_interface::default_event
 * sc_event_finder_t
 * tlm_event_finder_t

src/sysc/communication/sc_event_finder.h

@@ -123,9 +123,10 @@ const sc_event&
 sc_event_finder_t<IF>::find_event( sc_interface* if_p ) const
 {
     const IF* iface = ( if_p ) ? dynamic_cast<const IF*>( if_p ) :
-		                 dynamic_cast<const IF*>( port().get_interface() );
+                                 dynamic_cast<const IF*>( port().get_interface() );
     if( iface == 0 ) {
-		report_error( SC_ID_FIND_EVENT_, "port is not bound" );
+        report_error( SC_ID_FIND_EVENT_, "port is not bound" );
+        return sc_event::none;
     }
     return (const_cast<IF*>( iface )->*m_event_method) ();
 }

src/sysc/communication/sc_interface.cpp

@@ -52,7 +52,7 @@ const sc_event&
 sc_interface::default_event() const
 {
     SC_REPORT_WARNING( SC_ID_NO_DEFAULT_EVENT_, 0 );
-    return m_never_notified;
+    return sc_event::none;
 }
 
 
@@ -67,12 +67,6 @@ sc_interface::~sc_interface()
 sc_interface::sc_interface()
 {}
 
-
-// special event for never notified cases, note the special name to keep
-// it out of the named event structures.
-
-sc_event sc_interface::m_never_notified( sc_event::kernel_event );
-
 } // namespace sc_core
 
 // $Log: sc_interface.cpp,v $

src/sysc/communication/sc_interface.h

@@ -68,17 +68,6 @@ class SC_API sc_interface
     // disabled
     sc_interface( const sc_interface& );
     sc_interface& operator = ( const sc_interface& );
-
-private:
-
-    static sc_event m_never_notified;
-
-#if defined(__SUNPRO_CC) && (__SUNPRO_CC == 0x520)
-    // Workaround for a bug in the Sun WorkShop 6 update 2 compiler.
-    // An empty virtual base class can cause the optimizer to
-    // generate wrong code.
-    char dummy;
-#endif
 };
 
 } // namespace sc_core

src/sysc/kernel/sc_event.cpp

@@ -52,6 +52,9 @@ using std::strncmp;
 //  The event class.
 // ----------------------------------------------------------------------------
 
+// kernel-internal event, that is never notified
+const sc_event sc_event::none( kernel_event, "none" );
+
 const char*
 sc_event::basename() const
 {

src/sysc/kernel/sc_event.h

@@ -260,7 +260,6 @@ class SC_API sc_event
     friend class sc_method_process;
     friend class sc_thread_process;
     friend void sc_thread_cor_fn( void* arg );
-    friend class sc_interface;
     friend class sc_clock;
     friend class sc_event_queue;
     friend class sc_signal_channel;
@@ -295,6 +294,8 @@ class SC_API sc_event
     sc_event_and_expr operator & ( const sc_event& ) const;
     sc_event_and_expr operator & ( const sc_event_and_list& ) const;
 
+    // never notified event
+    static const sc_event none;
 
 private:
 

src/tlm_core/tlm_1/tlm_req_rsp/tlm_ports/tlm_event_finder.h

@@ -66,6 +66,7 @@ tlm_event_finder_t<IF,T>::find_event( sc_core::sc_interface* if_p ) const
                                  dynamic_cast<const IF*>( port().get_interface() );
     if( iface == 0 ) {
         report_error( sc_core::SC_ID_FIND_EVENT_, "port is not bound" );
+        return sc_core::sc_event::none;
     }
     return (const_cast<IF*>( iface )->*m_event_method) ( 0 );
 }