Bug 1323468, part 4 - inline |from| in Transition. r=kanru

MozReview-Commit-ID: LwcpNikbe2b

--HG--
extra : rebase_source : 25ace3d2f3e408ca48c72f6e8ea11217990a6f12

ipc/ipdl/ipdl/lower.py

@@ -1665,7 +1665,6 @@ class _GenerateProtocolCode(ipdl.ast.Visitor):
 
         # bool Transition(MessageType msg, State* next)
         # The state we are transitioning from is stored in *next.
-        fromvar = ExprVar('from')
         msgtypevar = ExprVar('msg')
         nextvar = ExprVar('next')
 
@@ -1675,7 +1674,7 @@ class _GenerateProtocolCode(ipdl.ast.Visitor):
                      Decl(Type('State', ptr=1), nextvar.name) ],
             ret=Type.VOID))
 
-        fromswitch = StmtSwitch(fromvar)
+        fromswitch = StmtSwitch(ExprDeref(nextvar))
 
         # special case for Null
         nullerrorblock = Block()
@@ -1714,8 +1713,6 @@ class _GenerateProtocolCode(ipdl.ast.Visitor):
             StmtBreak() ])
         fromswitch.addcase(DefaultLabel(), unreachedblock)
 
-        transitionfunc.addstmt(StmtDecl(Decl(Type('State'), fromvar.name),
-                                        init=ExprDeref(nextvar)))
         transitionfunc.addstmt(fromswitch)
 
         return transitionfunc