Context becomes a Maybe in the GHC AST

This prevents noLoc's appearing in the ParsedSource.

Match the change in GHC.

3 files changed, 23 insertions, 19 deletions

diff --git a/haddock-api/src/Haddock/Backends/Hoogle.hs b/haddock-api/src/Haddock/Backends/Hoogle.hs
index f7e1c77b..1a0cccf7 100644
--- a/haddock-api/src/Haddock/Backends/Hoogle.hs
+++ b/haddock-api/src/Haddock/Backends/Hoogle.hs
@@ -281,7 +281,7 @@ ppCtor dflags _dat subdocs (ConDeclGADT { con_names = names
         name = out dflags $ map unL names
         con_sig_ty = HsSig noExtField outer_bndrs theta_ty where
           theta_ty = case mcxt of
-            Just theta -> noLoc (HsQualTy { hst_xqual = noExtField, hst_ctxt = theta, hst_body = tau_ty })
+            Just theta -> noLoc (HsQualTy { hst_xqual = noExtField, hst_ctxt = Just theta, hst_body = tau_ty })
             Nothing -> tau_ty
           tau_ty = foldr mkFunTy res_ty $
             case args of PrefixConGADT pos_args -> map hsScaledThing pos_args
diff --git a/haddock-api/src/Haddock/Backends/LaTeX.hs b/haddock-api/src/Haddock/Backends/LaTeX.hs
index df1f94e6..e2e16947 100644
--- a/haddock-api/src/Haddock/Backends/LaTeX.hs
+++ b/haddock-api/src/Haddock/Backends/LaTeX.hs
@@ -25,7 +25,7 @@ import GHC.Utils.Ppr hiding (Doc, quote)
 import qualified GHC.Utils.Ppr as Pretty
 
 import GHC.Types.Basic        ( PromotionFlag(..) )
-import GHC
+import GHC hiding (fromMaybeContext )
 import GHC.Types.Name.Occurrence
 import GHC.Types.Name        ( nameOccName )
 import GHC.Types.Name.Reader ( rdrNameOcc )
@@ -597,12 +597,12 @@ rDoc = maybeDoc . fmap latexStripTrailingWhitespace
 -------------------------------------------------------------------------------
 
 
-ppClassHdr :: Bool -> Located [LHsType DocNameI] -> DocName
+ppClassHdr :: Bool -> Maybe (Located [LHsType DocNameI]) -> DocName
            -> LHsQTyVars DocNameI -> [Located ([Located DocName], [Located DocName])]
            -> Bool -> LaTeX
 ppClassHdr summ lctxt n tvs fds unicode =
   keyword "class"
-  <+> (if not . null . unLoc $ lctxt then ppLContext lctxt unicode else empty)
+  <+> (if not (null $ fromMaybeContext lctxt) then ppLContext lctxt unicode else empty)
   <+> ppAppDocNameNames summ n (tyvarNames tvs)
   <+> ppFds fds unicode
 
@@ -806,7 +806,7 @@ ppSideBySideConstr subdocs unicode leader (L _ con) =
                 , con_ex_tvs = tyVars
                 , con_forall = L _ forall_
                 , con_mb_cxt = cxt
-                } -> let context = unLoc (fromMaybe (noLoc []) cxt)
+                } -> let context = fromMaybeContext cxt
                          header_ = ppConstrHdr forall_ tyVars context unicode
                      in case det of
         -- Prefix constructor, e.g. 'Just a'
@@ -980,9 +980,11 @@ ppTypeApp n ts ppDN ppT = ppDN n <+> hsep (map ppT ts)
 -------------------------------------------------------------------------------
 
 
-ppLContext, ppLContextNoArrow :: Located (HsContext DocNameI) -> Bool -> LaTeX
-ppLContext        = ppContext        . unLoc
-ppLContextNoArrow = ppContextNoArrow . unLoc
+ppLContext, ppLContextNoArrow :: Maybe (LHsContext DocNameI) -> Bool -> LaTeX
+ppLContext        Nothing _ = empty
+ppLContext        (Just ctxt) unicode  = ppContext        (unLoc ctxt) unicode
+ppLContextNoArrow Nothing _ = empty
+ppLContextNoArrow (Just ctxt) unicode = ppContextNoArrow (unLoc ctxt) unicode
 
 ppContextNoLocsMaybe :: [HsType DocNameI] -> Bool -> Maybe LaTeX
 ppContextNoLocsMaybe [] _ = Nothing
diff --git a/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs b/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs
index de37e42a..e48f9bdd 100644
--- a/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs
+++ b/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs
@@ -37,7 +37,7 @@ import           Text.XHtml hiding     ( name, title, p, quote )
 
 import GHC.Core.Type ( Specificity(..) )
 import GHC.Types.Basic (PromotionFlag(..), isPromoted)
-import GHC hiding (LexicalFixity(..))
+import GHC hiding (LexicalFixity(..), fromMaybeContext)
 import GHC.Exts
 import GHC.Types.Name
 import GHC.Data.BooleanFormula
@@ -167,7 +167,7 @@ ppSubSigLike unicode qual typ argDocs subdocs sep emptyCtxts = do_sig_args 0 sep
         leader' = leader <+> ppForAllPart unicode qual tele
 
     do_args n leader (HsQualTy _ lctxt ltype)
-      | null (unLoc lctxt)
+      | null (fromMaybeContext lctxt)
       = do_largs n leader ltype
       | otherwise
       = (leader <+> ppLContextNoArrow lctxt unicode qual emptyCtxts, Nothing, [])
@@ -435,10 +435,12 @@ ppTypeApp n ts ppDN ppT = ppDN Prefix n <+> hsep (map ppT ts)
 -------------------------------------------------------------------------------
 
 
-ppLContext, ppLContextNoArrow :: Located (HsContext DocNameI) -> Unicode
+ppLContext, ppLContextNoArrow :: Maybe (LHsContext DocNameI) -> Unicode
                               -> Qualification -> HideEmptyContexts -> Html
-ppLContext        = ppContext        . unLoc
-ppLContextNoArrow = ppContextNoArrow . unLoc
+ppLContext        Nothing  u q h = ppContext        []        u q h
+ppLContext        (Just c) u q h = ppContext        (unLoc c) u q h
+ppLContextNoArrow Nothing  u q h = ppContextNoArrow []        u q h
+ppLContextNoArrow (Just c) u q h = ppContextNoArrow (unLoc c) u q h
 
 ppContextNoArrow :: HsContext DocNameI -> Unicode -> Qualification -> HideEmptyContexts -> Html
 ppContextNoArrow cxt unicode qual emptyCtxts = fromMaybe noHtml $
@@ -472,12 +474,12 @@ ppHsContext cxt unicode qual = parenList (map (ppType unicode qual HideEmptyCont
 -------------------------------------------------------------------------------
 
 
-ppClassHdr :: Bool -> Located [LHsType DocNameI] -> DocName
+ppClassHdr :: Bool -> Maybe (Located [LHsType DocNameI]) -> DocName
            -> LHsQTyVars DocNameI -> [Located ([Located DocName], [Located DocName])]
            -> Unicode -> Qualification -> Html
 ppClassHdr summ lctxt n tvs fds unicode qual =
   keyword "class"
-  <+> (if not . null . unLoc $ lctxt then ppLContext lctxt unicode qual HideEmptyContexts else noHtml)
+  <+> (if not (null $ fromMaybeContext lctxt) then ppLContext lctxt unicode qual HideEmptyContexts else noHtml)
   <+> ppAppDocNameTyVarBndrs summ unicode qual n (hsQTvExplicit tvs)
   <+> ppFds fds unicode qual
 
@@ -855,7 +857,7 @@ ppShortConstrParts summary dataInst con unicode qual
                 , con_ex_tvs = tyVars
                 , con_forall = L _ forall_
                 , con_mb_cxt = cxt
-                } -> let context = unLoc (fromMaybe (noLoc []) cxt)
+                } -> let context = fromMaybeContext cxt
                          header_ = ppConstrHdr forall_ tyVars context unicode qual
                      in case det of
 
@@ -927,7 +929,7 @@ ppSideBySideConstr subdocs fixities unicode pkg qual (L _ con)
                 , con_ex_tvs = tyVars
                 , con_forall = L _ forall_
                 , con_mb_cxt = cxt
-                } -> let context = unLoc (fromMaybe (noLoc []) cxt)
+                } -> let context = fromMaybeContext cxt
                          header_ = ppConstrHdr forall_ tyVars context unicode qual
                      in case det of
         -- Prefix constructor, e.g. 'Just a'
@@ -1181,13 +1183,13 @@ patSigContext sig_typ | hasNonEmptyContext typ && isFirstContextEmpty typ =  Sho
     hasNonEmptyContext t =
       case unLoc t of
         HsForAllTy _ _ s -> hasNonEmptyContext s
-        HsQualTy _ cxt s -> if null (unLoc cxt) then hasNonEmptyContext s else True
+        HsQualTy _ cxt s -> if null (fromMaybeContext cxt) then hasNonEmptyContext s else True
         HsFunTy _ _ _ s    -> hasNonEmptyContext s
         _ -> False
     isFirstContextEmpty t =
       case unLoc t of
         HsForAllTy _ _ s -> isFirstContextEmpty s
-        HsQualTy _ cxt _ -> null (unLoc cxt)
+        HsQualTy _ cxt _ -> null (fromMaybeContext cxt)
         HsFunTy _ _ _ s    -> isFirstContextEmpty s
         _ -> False