mem: Add predecessor to SenderState base class

This patch adds a predecessor field to the SenderState base class to
make the process of linking them up more uniform, and enable a
traversal of the stack without knowing the specific type of the
subclasses.

There are a number of simplifications done as part of changing the
SenderState, particularly in the RubyTest.

1 files changed, 2 insertions, 9 deletions

diff --git a/src/mem/addr_mapper.hh b/src/mem/addr_mapper.hh
index 887635999..6604096bd 100644
--- a/src/mem/addr_mapper.hh
+++ b/src/mem/addr_mapper.hh
@@ -87,23 +87,16 @@ class AddrMapper : public MemObject
       public:
 
         /**
-         * Construct a new sender state and remember the original one
-         * so that we can implement a stack.
+         * Construct a new sender state to remember the original address.
          *
-         * @param _origSenderState Sender state to remember
          * @param _origAddr Address before remapping
          */
-        AddrMapperSenderState(SenderState* _origSenderState,
-                              Addr _origAddr)
-            : origSenderState(_origSenderState), origAddr(_origAddr)
+        AddrMapperSenderState(Addr _origAddr) : origAddr(_origAddr)
         { }
 
         /** Destructor */
         ~AddrMapperSenderState() { }
 
-        /** Pointer to old sender state of packet */
-        SenderState* origSenderState;
-
         /** The original address the packet was destined for */
         Addr origAddr;