X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FstgSyn%2FCoreToStg.lhs;h=64f9fe3ad3b5f153ec6b5bfb23b58f682f46e8f5;hp=66e2d6171d6a040176307d77c51415b928159173;hb=6ef2fc2ebf11755a54386f8e317d83cb19913be1;hpb=604121dfc02eaf2ba60d018bbc7f4c7b3e0698dd

diff --git a/compiler/stgSyn/CoreToStg.lhs b/compiler/stgSyn/CoreToStg.lhs
index 66e2d61..64f9fe3 100644
--- a/compiler/stgSyn/CoreToStg.lhs
+++ b/compiler/stgSyn/CoreToStg.lhs
@@ -548,6 +548,21 @@ coreToStgArgs (arg : args)	-- Non-type argument
 		       StgLit lit       -> StgLitArg lit
 		       _ 		-> pprPanic "coreToStgArgs" (ppr arg)
     in
+	-- WARNING: what if we have an argument like (v `cast` co)
+	-- 	    where 'co' changes the representation type?
+	--	    (This really only happens if co is unsafe.)
+	-- Then all the getArgAmode stuff in CgBindery will set the
+	-- cg_rep of the CgIdInfo based on the type of v, rather
+	-- than the type of 'co'.
+	-- This matters particularly when the function is a primop
+	-- or foreign call.
+	-- Wanted: a better solution than this hacky warning
+    let
+	arg_ty = exprType arg
+	stg_arg_ty = stgArgType stg_arg
+    in
+    WARN( isUnLiftedType arg_ty /= isUnLiftedType stg_arg_ty, 
+	  ptext SLIT("Dangerous-looking argument. Probable cause: bad unsafeCoerce#") $$ ppr arg)
     returnLne (stg_arg : stg_args, fvs)