X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FbasicTypes%2FIdInfo.lhs;h=a3124f359489c50c166d092602a503aa3847304c;hb=59a4ad63f93f4fd7b8ede74bb2ea36778fe25e06;hp=3261adf5ed784a6c2ec30becb638523f2f134679;hpb=dbcff8ab57f64bcc6abff68448fc33691410266e;p=ghc-hetmet.git

diff --git a/compiler/basicTypes/IdInfo.lhs b/compiler/basicTypes/IdInfo.lhs
index 3261adf..a3124f3 100644
--- a/compiler/basicTypes/IdInfo.lhs
+++ b/compiler/basicTypes/IdInfo.lhs
@@ -232,7 +232,8 @@ 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 +464,11 @@ 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 +485,17 @@ 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
+
+
 
 %************************************************************************
 %*									*
@@ -718,12 +732,9 @@ zapFragileInfo info = Just (info `setSpecInfo` emptySpecInfo
 type TickBoxId = Int
 
 data TickBoxOp 
-   = TickBox Module !TickBoxId  -- ^Tick box for Hpc-style coverage,
-				-- type = State# Void#
-   | BinaryTickBox Module !TickBoxId !TickBoxId
-    			  -- ^Binary tick box, with a tick for result = True, result = False,
-			  -- type = Bool -> Bool
+   = TickBox Module {-# UNPACK #-} !TickBoxId
+          -- ^Tick box for Hpc-style coverage
+
 instance Outputable TickBoxOp where
     ppr (TickBox mod n)         = ptext SLIT("tick") <+> ppr (mod,n)
-    ppr (BinaryTickBox mod t f) = ptext SLIT("btick") <+> ppr (mod,t,f)
 \end{code}