Fix Trac #1988; keep the ru_fn field of a RULE up to date

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

diff --git a/compiler/basicTypes/IdInfo.lhs b/compiler/basicTypes/IdInfo.lhs
index 38e2a2e..7eacbd8 100644 (file)
--- a/compiler/basicTypes/IdInfo.lhs
+++ b/compiler/basicTypes/IdInfo.lhs
@@ -8,6 +8,13 @@
 Haskell. [WDP 94/11])
 
 \begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
 module IdInfo (
        GlobalIdDetails(..), notGlobalId,       -- Not abstract
 
@@ -65,13 +72,16 @@ module IdInfo (
 
        -- Specialisation
        SpecInfo(..), specInfo, setSpecInfo, isEmptySpecInfo, 
-       specInfoFreeVars, specInfoRules, seqSpecInfo,
+       specInfoFreeVars, specInfoRules, seqSpecInfo, setSpecInfoHead,
 
        -- CAF info
        CafInfo(..), cafInfo, ppCafInfo, setCafInfo, mayHaveCafRefs,
 
         -- Lambda-bound variable info
-        LBVarInfo(..), lbvarInfo, setLBVarInfo, noLBVarInfo, hasNoLBVarInfo
+        LBVarInfo(..), lbvarInfo, setLBVarInfo, noLBVarInfo, hasNoLBVarInfo,
+
+        -- Tick-box info
+        TickBoxOp(..), TickBoxId,
     ) where
 
 #include "HsVersions.h"
@@ -79,6 +89,7 @@ module IdInfo (
 import CoreSyn
 import Class
 import PrimOp
+import Name
 import Var
 import VarSet
 import BasicTypes
@@ -87,11 +98,11 @@ import TyCon
 import ForeignCall
 import NewDemand
 import Outputable      
+import Module
 
 import Data.Maybe
 
 #ifdef OLD_STRICTNESS
-import Name
 import Demand
 import qualified Demand
 import Util
@@ -215,7 +226,7 @@ seqNewDemandInfo (Just dmd) = seqDemand dmd
 
 %************************************************************************
 %*                                                                     *
-\subsection{GlobalIdDetails
+\subsection{GlobalIdDetails}
 %*                                                                     *
 %************************************************************************
 
@@ -228,7 +239,8 @@ data GlobalIdDetails
   = VanillaGlobal              -- Imported from elsewhere, a default method Id.
 
   | RecordSelId                 -- The Id for a record selector
-    { sel_tycon   :: TyCon
+    { sel_tycon   :: TyCon     -- For a data type family, this is the *instance* TyCon
+                               --      not the family TyCon
     , sel_label   :: FieldLabel
     , sel_naughty :: Bool       -- True <=> naughty
     }                          -- See Note [Naughty record selectors]
@@ -246,6 +258,8 @@ data GlobalIdDetails
   | PrimOpId PrimOp            -- The Id for a primitive operator
   | FCallId ForeignCall                -- The Id for a foreign call
 
+  | TickBoxOpId TickBoxOp      -- The Id for a tick box (both traditional and binary)
+
   | NotGlobalId                        -- Used as a convenient extra return value from globalIdDetails
     
 notGlobalId = NotGlobalId
@@ -258,6 +272,7 @@ instance Outputable GlobalIdDetails where
     ppr (ClassOpId _)     = ptext SLIT("[ClassOp]")
     ppr (PrimOpId _)      = ptext SLIT("[PrimOp]")
     ppr (FCallId _)       = ptext SLIT("[ForeignCall]")
+    ppr (TickBoxOpId _)   = ptext SLIT("[TickBoxOp]")
     ppr (RecordSelId {})  = ptext SLIT("[RecSel]")
 \end{code}
 
@@ -456,9 +471,13 @@ type InlinePragInfo = Activation
 %************************************************************************
 
 \begin{code}
--- CoreRules is used only in an idSpecialisation (move to IdInfo?)
 data SpecInfo 
-  = SpecInfo [CoreRule] VarSet -- Locally-defined free vars of RHSs
+  = SpecInfo 
+       [CoreRule] 
+       VarSet          -- Locally-defined free vars of *both* LHS and RHS 
+                       -- of rules.  I don't think it needs to include the
+                       -- ru_fn though.
+                       -- Note [Rule dependency info]
 
 emptySpecInfo :: SpecInfo
 emptySpecInfo = SpecInfo [] emptyVarSet
@@ -472,9 +491,26 @@ specInfoFreeVars (SpecInfo _ fvs) = fvs
 specInfoRules :: SpecInfo -> [CoreRule]
 specInfoRules (SpecInfo rules _) = rules
 
+setSpecInfoHead :: Name -> SpecInfo -> SpecInfo
+setSpecInfoHead fn (SpecInfo rules fvs)
+  = SpecInfo (map set_head rules) fvs
+  where
+    set_head rule = rule { ru_fn = fn }
+
 seqSpecInfo (SpecInfo rules fvs) = seqRules rules `seq` seqVarSet fvs
 \end{code}
 
+Note [Rule dependency info]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+THe VarSet in a SpecInfo is used for dependency analysis in the 
+occurrence analyser.  We must track free vars in *both* lhs and rhs.  Why both?  
+Consider
+       x = y
+       RULE f x = 4
+Then if we substitute y for x, we'd better do so in the
+ rule's LHS too, so we'd better ensure the dependency is respected
+
+
 
 %************************************************************************
 %*                                                                     *
@@ -676,11 +712,11 @@ zapLamInfo info@(IdInfo {occInfo = occ, newDemandInfo = demand})
        -- The "unsafe" occ info is the ones that say I'm not in a lambda
        -- because that might not be true for an unsaturated lambda
     is_safe_occ (OneOcc in_lam _ _) = in_lam
-    is_safe_occ other              = True
+    is_safe_occ _other             = True
 
     safe_occ = case occ of
                 OneOcc _ once int_cxt -> OneOcc insideLam once int_cxt
-                other                 -> occ
+                _other                -> occ
 
     is_safe_dmd Nothing    = True
     is_safe_dmd (Just dmd) = not (isStrictDmd dmd)
@@ -695,6 +731,29 @@ zapDemandInfo info@(IdInfo {newDemandInfo = dmd})
 
 \begin{code}
 zapFragileInfo :: IdInfo -> Maybe IdInfo
-zapFragileInfo info = Just (info `setSpecInfo` emptySpecInfo
-                                 `setUnfoldingInfo` NoUnfolding)
+-- Zap info that depends on free variables
+zapFragileInfo info 
+  = Just (info `setSpecInfo` emptySpecInfo
+              `setWorkerInfo` NoWorker
+               `setUnfoldingInfo` NoUnfolding
+              `setOccInfo` if isFragileOcc occ then NoOccInfo else occ)
+  where
+    occ = occInfo info
+\end{code}
+
+%************************************************************************
+%*                                                                     *
+\subsection{TickBoxOp}
+%*                                                                     *
+%************************************************************************
+
+\begin{code}
+type TickBoxId = Int
+
+data TickBoxOp 
+   = TickBox Module {-# UNPACK #-} !TickBoxId
+          -- ^Tick box for Hpc-style coverage
+
+instance Outputable TickBoxOp where
+    ppr (TickBox mod n)         = ptext SLIT("tick") <+> ppr (mod,n)
 \end{code}