[project @ 1998-06-08 11:45:09 by simonpj]

[ghc-hetmet.git] / ghc / compiler / coreSyn / FreeVars.lhs

diff --git a/ghc/compiler/coreSyn/FreeVars.lhs b/ghc/compiler/coreSyn/FreeVars.lhs
index 9619f49..b0b39e3 100644 (file)
--- a/ghc/compiler/coreSyn/FreeVars.lhs
+++ b/ghc/compiler/coreSyn/FreeVars.lhs
@@ -262,8 +262,11 @@ fvExpr id_cands tyvar_cands (Case expr alts)
        binder_ftvs = munge_id_ty binder
            -- We need to collect free tyvars from the binder
 
+-- Don't forget to notice that the idSpecVars of the binder
+-- are free in the whole expression; albeit not in the RHS or body
+
 fvExpr id_cands tyvar_cands (Let (NonRec binder rhs) body)
-  = (FVInfo (freeVarsOf rhs'   `combine` body_fvs)
+  = (FVInfo (freeVarsOf rhs'   `combine` body_fvs `combine` mkIdSet (idSpecVars binder))
            (freeTyVarsOf rhs' `combine` freeTyVarsOf body2 `combine` binder_ftvs)
            (leakinessOf rhs' `orLeak` leakinessOf body2),
      AnnLet (AnnNonRec binder rhs') body2)
@@ -288,7 +291,12 @@ fvExpr id_cands tyvar_cands (Let (Rec binds) body)
     FVInfo rhss_fvs rhss_tfvs leakiness_of_rhss
        = foldr1 combineFVInfo [info | (info,_) <- rhss']
 
-    binds_fvs        = rhss_fvs `minusIdSet` binders_set
+       -- Don't forget to notice that the idSpecVars of the binder
+       -- are free in the whole expression; albeit not in the RHS or body
+    binds_fvs        = (foldr (unionIdSets . mkIdSet . idSpecVars) rhss_fvs binders)
+                       `minusIdSet`
+                       binders_set
+
     body2            = fvExpr new_id_cands tyvar_cands body
     body_fvs         = freeVarsOf body2 `minusIdSet` binders_set
     binders_ftvs      = foldr (combine . munge_id_ty) noFreeTyVars binders
@@ -309,15 +317,8 @@ fvExpr id_cands tyvar_cands (Note other_note expr)
   where
     expr2@(fvinfo,_) = fvExpr id_cands tyvar_cands expr
 
--- fvRhs returns the annotated RHS, but it adds to the
--- free vars of the RHS the idSpecVars of the binder,
--- since those are, in truth, free in the definition.
 fvRhs id_cands tyvar_cands (bndr,rhs)
-  = (FVInfo fvs' ftvs leak, rhs')
-  where
-    (FVInfo fvs ftvs leak, rhs') = fvExpr id_cands tyvar_cands rhs
-    fvs' = fvs `unionIdSets` mkIdSet (idSpecVars bndr)
-
+  = fvExpr id_cands tyvar_cands rhs
 \end{code}
 
 \begin{code}