From: simonm <unknown>
Date: Tue, 25 Nov 1997 10:52:29 +0000 (+0000)
Subject: [project @ 1997-11-25 10:52:29 by simonm]
X-Git-Tag: Approx_2487_patches~1242
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=78f85b1ef880f3020a0a4c02d05d7009c9fc42ff;p=ghc-hetmet.git

[project @ 1997-11-25 10:52:29 by simonm]
fix for "TyCon used as Class" bug.
---

diff --git a/ghc/compiler/typecheck/TcEnv.lhs b/ghc/compiler/typecheck/TcEnv.lhs
index 32fdf22..e406b28 100644
--- a/ghc/compiler/typecheck/TcEnv.lhs
+++ b/ghc/compiler/typecheck/TcEnv.lhs
@@ -55,6 +55,7 @@ import UniqFM
 import Util		( zipEqual, zipWithEqual, zipWith3Equal, zipLazy,
 			  panic, pprPanic, pprTrace
 			)
+import Maybes		( maybeToBool )
 import Outputable
 \end{code}
 
@@ -175,14 +176,17 @@ tcLookupTyConByKey uniq
 
 tcLookupClass name
   = tcGetEnv		`thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) ->
---  pprTrace "tcLookupClass:" (hsep [text "Uniq:", pprUnique10 (uniqueOf name), text "; avail:", hsep (map (pprUnique10 . fst) (ufmToList ce))]) $
---  pprTrace "tcLookupClass:" (hsep [text "Uniq:", pprUnique (uniqueOf name), text "; avail:", hsep (map (pprUnique . fst) (ufmToList ce))]) $
     case lookupUFM ce name of
-	Just stuff -> returnTc stuff
-	Nothing	   -> 	-- Could be that he's using a type constructor as a class
-			case lookupUFM tce name of
-			  Just _ ->  failTc (tyConAsClassErr name)
-			  Nothing -> pprPanic "tcLookupClass:" (ppr PprShowAll name)
+	Just stuff         -- Common case: it's ok
+	  -> returnTc stuff
+
+	Nothing		   -- Could be that he's using a type constructor as a class
+	  |  maybeToBool (maybeWiredInTyConName name)
+	  || maybeToBool (lookupUFM tce name)
+	  -> failTc (tyConAsClassErr name)
+
+	  | otherwise      -- Wierd!  Renamer shouldn't let this happen
+	  -> pprPanic "tcLookupClass:" (ppr PprShowAll name)
 
 tcLookupClassByKey uniq
   = tcGetEnv		`thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) ->