Fix Trac #2720: inlining and casts

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

diff --git a/compiler/coreSyn/CorePrep.lhs b/compiler/coreSyn/CorePrep.lhs
index f0c2d9f..e90a12a 100644 (file)
--- a/compiler/coreSyn/CorePrep.lhs
+++ b/compiler/coreSyn/CorePrep.lhs
@@ -634,7 +634,7 @@ mkBinds (Floats _ binds) body
 etaExpandRhs :: CoreBndr -> CoreExpr -> UniqSM CoreExpr
 etaExpandRhs bndr rhs = do
        -- Eta expand to match the arity claimed by the binder
-       -- Remember, after CorePrep we must not change arity
+       -- Remember, CorePrep must not change arity
        --
        -- Eta expansion might not have happened already, 
        -- because it is done by the simplifier only when 
@@ -663,7 +663,12 @@ etaExpandRhs bndr rhs = do
        --              f = /\a -> \y -> let s = h 3 in g s y
        --
     us <- getUniquesM
-    return (etaExpand arity us rhs (idType bndr))
+    let eta_rhs = etaExpand arity us rhs (idType bndr)
+
+    ASSERT2( manifestArity eta_rhs == arity, (ppr bndr <+> ppr arity <+> ppr (exprArity rhs)) 
+                                             $$ ppr rhs $$ ppr eta_rhs )
+       -- Assertion checks that eta expansion was successful
+      return eta_rhs
   where
        -- For a GlobalId, take the Arity from the Id.
        -- It was set in CoreTidy and must not change
@@ -841,5 +846,5 @@ newVar :: Type -> UniqSM Id
 newVar ty
  = seqType ty `seq` do
      uniq <- getUniqueM
-     return (mkSysLocal FSLIT("sat") uniq ty)
+     return (mkSysLocal (fsLit "sat") uniq ty)
 \end{code}