Add error message to mkConcSm for unsupported expressions.

Previously, there was only a cryptic message from ghc, now it also
mentions the unsupported expression.

diff --git a/VHDL.hs b/VHDL.hs
index 229ba5caff3f83d643745156b818aad868055c0a..a450c04962d21d8ae4b5803c0b72ce8878a8a114 100644 (file)
--- a/VHDL.hs
+++ b/VHDL.hs
@@ -350,6 +350,7 @@ mkConcSm (bndr, (Case (Var scrut) b ty [(_, _, Var false), (con, _, Var true)]))
     return $ mkCondAssign (Left bndr) cond_expr true_expr false_expr
 mkConcSm (_, (Case (Var _) _ _ alts)) = error "VHDL.mkConcSm Not in normal form: Case statement with more than two alternatives"
 mkConcSm (_, Case _ _ _ _) = error "VHDL.mkConcSm Not in normal form: Case statement has does not have a simple variable as scrutinee"
+mkConcSm (bndr, expr) = error $ "VHDL.mkConcSM Unsupported binding in let expression: " ++ pprString bndr ++ " = " ++ pprString expr
 
 -- Create an unconditional assignment statement
 mkUncondAssign ::