Add mkHsCoerce to avoid junk in typechecked code

[ghc-hetmet.git] / ghc / compiler / typecheck / TcMatches.lhs

diff --git a/ghc/compiler/typecheck/TcMatches.lhs b/ghc/compiler/typecheck/TcMatches.lhs
index d6e66ef..d62eacd 100644 (file)
--- a/ghc/compiler/typecheck/TcMatches.lhs
+++ b/ghc/compiler/typecheck/TcMatches.lhs
@@ -17,7 +17,7 @@ import {-# SOURCE #-} TcExpr( tcSyntaxOp, tcInferRho, tcMonoExpr, tcPolyExpr )
 import HsSyn           ( HsExpr(..), LHsExpr, MatchGroup(..),
                          Match(..), LMatch, GRHSs(..), GRHS(..), 
                          Stmt(..), LStmt, HsMatchContext(..), HsStmtContext(..),
-                         pprMatch, isIrrefutableHsPat,
+                         pprMatch, isIrrefutableHsPat, mkHsCoerce,
                          pprMatchContext, pprStmtContext, 
                          noSyntaxExpr, matchGroupArity, pprMatches,
                          ExprCoFn )
@@ -471,7 +471,7 @@ tcMDoStmt tc_rhs ctxt (RecStmt stmts laterNames recNames _ _) res_ty thing_insid
                -- poly_id may have a polymorphic type
                -- but mono_ty is just a monomorphic type variable
             ; co_fn <- tcSubExp (idType poly_id) mono_ty
-            ; return (HsCoerce co_fn (HsVar poly_id)) }
+            ; return (mkHsCoerce co_fn (HsVar poly_id)) }
 
 tcMDoStmt tc_rhs ctxt stmt res_ty thing_inside
   = pprPanic "tcMDoStmt: unexpected Stmt" (ppr stmt)