Refactor renamer datastructures

This patch significantly refactors key renamer datastructures (primarily Avail
and GlobalRdrElt) in order to treat DuplicateRecordFields in a more robust way.
In particular it allows the extension to be used with pattern synonyms (fixes
where mangled record selector names could be printed instead of field labels
(e.g. with -Wpartial-fields or hole fits, see new tests).

The key idea is the introduction of a new type GreName for names that may
represent either normal entities or field labels.  This is then used in
GlobalRdrElt and AvailInfo, in place of the old way of representing fields
using FldParent (yuck) and an extra list in AvailTC.

Updates the haddock submodule.

1 files changed, 4 insertions, 4 deletions

diff --git a/compiler/GHC/HsToCore/Quote.hs b/compiler/GHC/HsToCore/Quote.hs
index 7f675e8253..d39a6d716a 100644
--- a/compiler/GHC/HsToCore/Quote.hs
+++ b/compiler/GHC/HsToCore/Quote.hs
@@ -283,7 +283,7 @@ repTopDs group@(HsGroup { hs_valds   = valds
                         , hs_docs    = docs })
  = do { let { bndrs  = hsScopedTvBinders valds
                        ++ hsGroupBinders group
-                       ++ hsPatSynSelectors valds
+                       ++ map extFieldOcc (hsPatSynSelectors valds)
             ; instds = tyclds >>= group_instds } ;
         ss <- mkGenSyms bndrs ;
 
@@ -1888,7 +1888,7 @@ rep_bind (L loc (PatSynBind _ (PSB { psb_id   = syn
     mkGenArgSyms (InfixCon arg1 arg2) = mkGenSyms [unLoc arg1, unLoc arg2]
     mkGenArgSyms (RecCon fields)
       = do { let pats = map (unLoc . recordPatSynPatVar) fields
-                 sels = map (unLoc . recordPatSynSelectorId) fields
+                 sels = map (extFieldOcc . recordPatSynField) fields
            ; ss <- mkGenSyms sels
            ; return $ replaceNames (zip sels pats) ss }
 
@@ -1918,9 +1918,9 @@ repPatSynArgs (InfixCon arg1 arg2)
        ; arg2' <- lookupLOcc arg2
        ; repInfixPatSynArgs arg1' arg2' }
 repPatSynArgs (RecCon fields)
-  = do { sels' <- repList nameTyConName lookupLOcc sels
+  = do { sels' <- repList nameTyConName (lookupOcc . extFieldOcc) sels
        ; repRecordPatSynArgs sels' }
-  where sels = map recordPatSynSelectorId fields
+  where sels = map recordPatSynField fields
 
 repPrefixPatSynArgs :: Core [TH.Name] -> MetaM (Core (M TH.PatSynArgs))
 repPrefixPatSynArgs (MkC nms) = rep2 prefixPatSynName [nms]