slicc: support for transitions with a wildcard next state

This patches adds support for transitions of the form:

transition(START, EVENTS, *) { ACTIONS }

This allows a machine to collapse states that differ only in the next state
transition to collapse into one, and can help shorten/simplfy some protocols
significantly.

When * is encountered as an end state of a transition, the next state is
determined by calling the machine-specific getNextState function. The next
state is determined before any actions of the transition execute, and
therefore the next state calculation cannot depend on any of the transition
actions.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/mem/slicc/symbols/State.py b/src/mem/slicc/symbols/State.py
index 123693256..164c585f6 100644
--- a/src/mem/slicc/symbols/State.py
+++ b/src/mem/slicc/symbols/State.py
@@ -30,5 +30,13 @@ from slicc.symbols.Symbol import Symbol
 class State(Symbol):
     def __repr__(self):
         return "[State: %s]" % self.ident
+    def isWildcard(self):
+        return False
+
+class WildcardState(State):
+    def __repr__(self):
+        return "[State: *]"
+    def isWildcard(self):
+        return True
 
 __all__ = [ "State" ]