X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FbasicTypes%2FIdInfo.lhs;h=e64e255a9537e9485baae0d0057826d156833d28;hb=3ad311341e189e574139921bd98449d7aed9ba26;hp=02ef0db1429b223f91011714dfb6bd61856cfc6d;hpb=7eb8be6b5fcd80c4d9dfde6990dcb9fec4062d6b;p=ghc-hetmet.git

diff --git a/compiler/basicTypes/IdInfo.lhs b/compiler/basicTypes/IdInfo.lhs
index 02ef0db..e64e255 100644
--- 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
 
@@ -232,7 +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]
@@ -463,9 +471,11 @@ 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
+			-- Note [Rule dependency info]
 
 emptySpecInfo :: SpecInfo
 emptySpecInfo = SpecInfo [] emptyVarSet
@@ -482,6 +492,17 @@ specInfoRules (SpecInfo rules _) = rules
 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 respsected
+
+
 
 %************************************************************************
 %*									*
@@ -683,11 +704,11 @@ 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)
@@ -703,9 +724,13 @@ zapDemandInfo info@(IdInfo {newDemandInfo = dmd})
 \begin{code}
 zapFragileInfo :: IdInfo -> Maybe IdInfo
 -- Zap info that depends on free variables
-zapFragileInfo info = Just (info `setSpecInfo` emptySpecInfo
-				 `setWorkerInfo` NoWorker
-                                 `setUnfoldingInfo` NoUnfolding)
+zapFragileInfo info 
+  = Just (info `setSpecInfo` emptySpecInfo
+	       `setWorkerInfo` NoWorker
+               `setUnfoldingInfo` NoUnfolding
+	       `setOccInfo` if isFragileOcc occ then NoOccInfo else occ)
+  where
+    occ = occInfo info
 \end{code}
 
 %************************************************************************
@@ -718,8 +743,8 @@ zapFragileInfo info = Just (info `setSpecInfo` emptySpecInfo
 type TickBoxId = Int
 
 data TickBoxOp 
-   = TickBox Module !TickBoxId  -- ^Tick box for Hpc-style coverage,
-				-- type = State# Void#
+   = TickBox Module {-# UNPACK #-} !TickBoxId
+          -- ^Tick box for Hpc-style coverage
 
 instance Outputable TickBoxOp where
     ppr (TickBox mod n)         = ptext SLIT("tick") <+> ppr (mod,n)