Quickly added poison to the C++ backend

backends/GenerateC.hs

@@ -1500,6 +1500,7 @@ cgenProcess p = case p of
   -- PROCESSOR does nothing special.
   A.Processor m e p -> call genProcess p
   A.Alt m b s -> call genAlt b s
+  A.InjectPoison m ch -> call genPoison m ch
   A.ProcCall m n as -> call genProcCall n as
   A.IntrinsicProcCall m s as -> call genIntrinsicProc m s as
 

backends/GenerateCBased.hs

@@ -152,6 +152,7 @@ data GenOps = GenOps {
     -- | Generates a loop that maps over every element in a (potentially multi-dimensional) array
     genOverArray :: Meta -> A.Variable -> (SubscripterFunction -> Maybe (CGen ())) -> CGen (),
     genPar :: A.ParMode -> A.Structured A.Process -> CGen (),
+    genPoison :: Meta -> A.Variable -> CGen (),
     genProcCall :: A.Name -> [A.Actual] -> CGen (),
     genProcess :: A.Process -> CGen (),
     genRecordTypeSpec :: A.Name -> Bool -> [(A.Name, A.Type)] -> CGen (),

backends/GenerateCPPCSP.hs

@@ -74,6 +74,7 @@ cppgenOps = cgenOps {
     genOutputCase = cppgenOutputCase,
     genOutputItem = cppgenOutputItem,
     genPar = cppgenPar,
+    genPoison = cppgenPoison,
     genProcCall = cppgenProcCall,
     genReplicatorLoop = cppgenReplicatorLoop,
     genStop = cppgenStop,
@@ -201,6 +202,11 @@ genCPPCSPChannelOutput var
          (A.Chan A.DirUnknown _ _) -> do call genVariable var
                                          tell ["->writer()"]
          _ -> call genMissing $ "genCPPCSPChannelOutput used on something which does not support output: " ++ show var
+
+cppgenPoison :: Meta -> A.Variable -> CGen ()
+cppgenPoison _m var
+  = do call genVariable var
+       tell ["->poison();"]
 --}}}
 
 -- | C++CSP2 returns the number of seconds since the epoch as the time