X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcRnTypes.lhs;h=28bfd8ecb72a8d7c3e35335f1263367334ca1868;hp=ff8e3d630752d5b52bed1302b2a9010029acb082;hb=c04a5fe3e2867d59ce9757069fdd20c06c326724;hpb=6a104dcf597f27887f0f1ac82dba7051ed2fe0c3

diff --git a/compiler/typecheck/TcRnTypes.lhs b/compiler/typecheck/TcRnTypes.lhs
index ff8e3d6..28bfd8e 100644
--- a/compiler/typecheck/TcRnTypes.lhs
+++ b/compiler/typecheck/TcRnTypes.lhs
@@ -29,7 +29,7 @@ module TcRnTypes(
 
 	-- Insts
 	Inst(..), EqInstCo, InstOrigin(..), InstLoc(..), 
-	pprInstLoc, pprInstArising, instLocSpan, instLocOrigin,
+	pprInstLoc, pprInstArising, instLocSpan, instLocOrigin, setInstLoc,
 	LIE, emptyLIE, unitLIE, plusLIE, consLIE, instLoc, instSpan,
 	plusLIEs, mkLIE, isEmptyLIE, lieToList, listToLIE,
 
@@ -868,6 +868,9 @@ data InstLoc = InstLoc InstOrigin SrcSpan ErrCtxt
 instLoc :: Inst -> InstLoc
 instLoc inst = tci_loc inst
 
+setInstLoc :: Inst -> InstLoc -> Inst
+setInstLoc inst new_loc = inst { tci_loc = new_loc }
+
 instSpan :: Inst -> SrcSpan
 instSpan wanted = instLocSpan (instLoc wanted)
 
@@ -912,7 +915,13 @@ data InstOrigin
   | ExprSigOrigin	-- e :: ty
   | RecordUpdOrigin
   | ViewPatOrigin
+
   | InstScOrigin	-- Typechecking superclasses of an instance declaration
+
+  | NoScOrigin          -- A very special hack; see TcSimplify,
+			--   Note [Recursive instances and superclases]
+			   
+
   | DerivOrigin		-- Typechecking deriving
   | StandAloneDerivOrigin -- Typechecking stand-alone deriving
   | DefaultOrigin	-- Typechecking a default decl
@@ -936,6 +945,7 @@ instance Outputable InstOrigin where
     ppr TupleOrigin	      = ptext (sLit "a tuple")
     ppr NegateOrigin	      = ptext (sLit "a use of syntactic negation")
     ppr InstScOrigin	      = ptext (sLit "the superclasses of an instance declaration")
+    ppr NoScOrigin            = ptext (sLit "an instance declaration")
     ppr DerivOrigin	      = ptext (sLit "the 'deriving' clause of a data type declaration")
     ppr StandAloneDerivOrigin = ptext (sLit "a 'deriving' declaration")
     ppr DefaultOrigin	      = ptext (sLit "a 'default' declaration")