Two new warnings: arity differing from demand type, and strict IDs at top level

[ghc-hetmet.git] / compiler / basicTypes / Id.lhs

diff --git a/compiler/basicTypes/Id.lhs b/compiler/basicTypes/Id.lhs
index 798bde6..61a39f1 100644 (file)
--- a/compiler/basicTypes/Id.lhs
+++ b/compiler/basicTypes/Id.lhs
@@ -1,4 +1,5 @@
 %
+% (c) The University of Glasgow 2006
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
 \section[Id]{@Ids@: Value and constructor identifiers}
@@ -21,10 +22,10 @@ module Id (
        -- Modifying an Id
        setIdName, setIdUnique, Id.setIdType, setIdExported, setIdNotExported, 
        setIdInfo, lazySetIdInfo, modifyIdInfo, maybeModifyIdInfo,
-       zapLamIdInfo, zapDemandIdInfo, 
+       zapLamIdInfo, zapDemandIdInfo, zapFragileIdInfo,
 
        -- Predicates
-       isImplicitId, isDeadBinder, isDictId,
+       isImplicitId, isDeadBinder, isDictId, isStrictId,
        isExportedId, isLocalId, isGlobalId,
        isRecordSelector, isNaughtyRecordSelector,
        isClassOpId_maybe,
@@ -32,6 +33,7 @@ module Id (
        isFCallId, isFCallId_maybe,
        isDataConWorkId, isDataConWorkId_maybe, isDataConId_maybe, idDataCon,
        isBottomingId, idIsFrom,
+        isTickBoxOp, isTickBoxOp_maybe,
        hasNoBinding, 
 
        -- Inline pragma stuff
@@ -79,42 +81,29 @@ module Id (
 
 #include "HsVersions.h"
 
-
-import CoreSyn         ( Unfolding, CoreRule )
-import BasicTypes      ( Arity )
-import Var             ( Id, DictId,
-                         isId, isExportedId, isLocalId,
-                         idName, idType, idUnique, idInfo, isGlobalId,
-                         setIdName, setIdType, setIdUnique, 
-                         setIdExported, setIdNotExported,
-                         setIdInfo, lazySetIdInfo, modifyIdInfo, 
-                         maybeModifyIdInfo,
-                         globalIdDetails
-                       )
-import qualified Var   ( mkLocalId, mkGlobalId, mkExportedLocalId )
-import TyCon           ( FieldLabel, TyCon )
-import Type            ( Type, typePrimRep, addFreeTyVars, seqType, 
-                         splitTyConApp_maybe, PrimRep )
-import TcType          ( isDictTy )
-import TysPrim         ( statePrimTyCon )
+import CoreSyn
+import BasicTypes
+import qualified Var
+import Var hiding (mkLocalId, mkGlobalId, mkExportedLocalId)
+import TyCon
+import Type
+import TcType
+import TysPrim
 import IdInfo 
-
 #ifdef OLD_STRICTNESS
-import qualified Demand        ( Demand )
+import qualified Demand
 #endif
-import DataCon         ( DataCon, isUnboxedTupleCon )
-import NewDemand       ( Demand, StrictSig, topDmd, topSig, isBottomingSig )
-import Name            ( Name, OccName, nameIsLocalOrFrom, 
-                         mkSystemVarName, mkInternalName, getOccName,
-                         getSrcLoc ) 
-import Module          ( Module )
-import OccName         ( mkWorkerOcc )
-import Maybes          ( orElse )
-import SrcLoc          ( SrcLoc )
+import DataCon
+import NewDemand
+import Name
+import Module
+import OccName
+import Maybes
+import SrcLoc
 import Outputable
-import Unique          ( Unique, mkBuiltinUnique )
-import FastString      ( FastString )
-import StaticFlags     ( opt_NoStateHack )
+import Unique
+import FastString
+import StaticFlags
 
 -- infixl so you can say (id `set` a `set` b)
 infixl         1 `setIdUnfolding`,
@@ -160,13 +149,14 @@ mkLocalId :: Name -> Type -> Id
 mkLocalId name ty = mkLocalIdWithInfo name ty vanillaIdInfo
 
 -- SysLocal: for an Id being created by the compiler out of thin air...
+mkSysLocal :: FastString -> Unique -> Type -> Id
+mkSysLocal fs uniq ty = mkLocalId (mkSystemVarName uniq fs) ty
+
+
 -- UserLocal: an Id with a name the user might recognize...
 mkUserLocal :: OccName -> Unique -> Type -> SrcLoc -> Id
-mkSysLocal  :: FastString  -> Unique -> Type -> Id
 mkVanillaGlobal :: Name -> Type -> IdInfo -> Id
 
-mkSysLocal fs uniq ty = mkLocalId (mkSystemVarName uniq fs) ty
-
 mkUserLocal occ uniq ty loc = mkLocalId (mkInternalName    uniq occ loc) ty
 mkVanillaGlobal            = mkGlobalId VanillaGlobal
 \end{code}
@@ -324,6 +314,19 @@ isDeadBinder bndr | isId bndr = isDeadOcc (idOccInfo bndr)
                  | otherwise = False   -- TyVars count as not dead
 \end{code}
 
+\begin{code}
+isTickBoxOp :: Id -> Bool
+isTickBoxOp id = 
+  case globalIdDetails id of
+    TickBoxOpId tick -> True
+    _                -> False
+
+isTickBoxOp_maybe :: Id -> Maybe TickBoxOp
+isTickBoxOp_maybe id = 
+  case globalIdDetails id of
+    TickBoxOpId tick -> Just tick
+    _                -> Nothing
+\end{code}
 
 %************************************************************************
 %*                                                                     *
@@ -365,6 +368,20 @@ setIdNewStrictness id sig = modifyIdInfo (`setNewStrictnessInfo` Just sig) id
 
 zapIdNewStrictness :: Id -> Id
 zapIdNewStrictness id = modifyIdInfo (`setNewStrictnessInfo` Nothing) id
+\end{code}
+
+This predicate says whether the id has a strict demand placed on it or
+has a type such that it can always be evaluated strictly (e.g., an
+unlifted type, but see the comment for isStrictType).  We need to
+check separately whether <id> has a so-called "strict type" because if
+the demand for <id> hasn't been computed yet but <id> has a strict
+type, we still want (isStrictId <id>) to be True.
+\begin{code}
+isStrictId :: Id -> Bool
+isStrictId id
+  = ASSERT2( isId id, text "isStrictId: not an id: " <+> ppr id )
+           (isStrictDmd (idNewDemandInfo id)) || 
+           (isStrictType (idType id))
 
        ---------------------------------
        -- WORKER ID
@@ -524,9 +541,15 @@ clearOneShotLambda id
 \end{code}
 
 \begin{code}
+zapInfo :: (IdInfo -> Maybe IdInfo) -> Id -> Id
+zapInfo zapper id = maybeModifyIdInfo (zapper (idInfo id)) id
+
 zapLamIdInfo :: Id -> Id
-zapLamIdInfo id = maybeModifyIdInfo zapLamInfo id
+zapLamIdInfo = zapInfo zapLamInfo
+
+zapDemandIdInfo = zapInfo zapDemandInfo
 
-zapDemandIdInfo id = maybeModifyIdInfo zapDemandInfo id
+zapFragileIdInfo :: Id -> Id
+zapFragileIdInfo = zapInfo zapFragileInfo 
 \end{code}