Fix top-level comment position+whitespace bug

data/15-regressions.blt

@@ -993,3 +993,8 @@ func = do
       doeeRbaviceQzymin a b = olivhuwqbaq
       iqnz biwomeJhhujy _ _ | biwomeJhhujy < volpoqAsizmHdwpl = pure 0
   pure True
+
+#test comment-inside-decl
+func False = 0
+-- comment
+func True  = 1

source/library/Language/Haskell/Brittany/Internal/S2_SplitModule.hs

@@ -56,7 +56,9 @@ import           GHC.Parser.Annotation          ( DeltaPos
                                                   )
                                                 , EpaCommentTok(EpaEofComment)
                                                 )
-import           GHC.Types.SrcLoc               ( realSrcSpanEnd )
+import           GHC.Types.SrcLoc               ( realSrcSpanEnd
+                                                , realSrcSpanStart
+                                                )
 import qualified Language.Haskell.GHC.ExactPrint.Types
                                                as ExactPrint
 import qualified Language.Haskell.GHC.ExactPrint.Utils
@@ -161,12 +163,23 @@ enrichDecls
   :: ExactPrint.Pos -> [LHsDecl GhcPs] -> FinalList ModuleElement ExactPrint.Pos
 enrichDecls lastSpanEnd = \case
   [] -> finalPure $ lastSpanEnd
-  (L (SrcSpanAnn dAnn rlspan@(GHC.RealSrcSpan span _)) decl : declRest) ->
+  L (SrcSpanAnn dAnn rlspan@(GHC.RealSrcSpan span _)) decl : declRest ->
     case dAnn of
       EpAnn dAnchor items (EpaComments dComments) -> do
         let
-          withoutComments =
-            (L (SrcSpanAnn (EpAnn dAnchor items (EpaComments [])) rlspan) decl)
+          (innerComments, outerComments) =
+            partition
+              (\(L (Anchor anch _) _) ->
+                realSrcSpanStart anch < realSrcSpanEnd span
+              )
+              dComments
+          withoutOuterComments =
+            (L
+              (SrcSpanAnn (EpAnn dAnchor items (EpaComments innerComments))
+                          rlspan
+              )
+              decl
+            )
           commentExtract = \case
             L (GHC.Anchor anch _) EpaComment{} -> ExactPrint.ss2posEnd anch
           -- It would be really nice if `ExactPrint.ss2posEnd span` was
@@ -180,20 +193,27 @@ enrichDecls lastSpanEnd = \case
           -- throughout the code now. But optimizing it is not easy, and
           -- at worst it is larger constant factor on the size of the
           -- input, so it isn't _that_ bad.
-          fixedSpanEnd = SYB.everything
-            max
-            (SYB.mkQ (ExactPrint.ss2posEnd span) commentExtract)
-            decl
+          fixedSpanEnd =
+            SYB.everything
+              max
+              (SYB.mkQ (ExactPrint.ss2posEnd span) commentExtract)
+              decl
         case ExactPrint.ss2delta lastSpanEnd span of
           SameLine{} -> pure ()
           DifferentLine n _ ->
             finalYield $ MEWhitespace $ DifferentLine (n - 1) 1
-        let (afterComms, span2) = finalToList $ enrichComms fixedSpanEnd (reverse dComments)
-        let (immediate, later) = List.span (\case
-              MEComment{} -> True
-              _ -> False
-              ) afterComms
-        finalYield $ MEDecl withoutComments [ comm | MEComment comm <- immediate ]
+        let (afterComms, span2) = finalToList
+              $ enrichComms fixedSpanEnd (reverse outerComments)
+        let (immediate, later) =
+              List.span
+                (\case
+                  MEComment{} -> True
+                  _           -> False
+                )
+                afterComms
+        finalYield
+          $ MEDecl withoutOuterComments [ comm | MEComment comm <- immediate ]
+          -- $ MEDecl ldecl []
         later `forM_` finalYield
         enrichDecls span2 declRest
       EpAnn _anchor _items (EpaCommentsBalanced{}) ->

source/library/Language/Haskell/Brittany/Internal/StepOrchestrate.hs

@@ -151,8 +151,9 @@ processModule traceFunc conf inlineConf parsedModule = do
   --       MEExactModuleHead{}  -> useTraceFunc traceFunc "MEExactModuleHead"
   --       MEPrettyModuleHead{} -> useTraceFunc traceFunc "MEPrettyModuleHead"
   --       MEImportDecl{}       -> useTraceFunc traceFunc "MEImportDecl"
-  --       MEDecl{}             -> useTraceFunc traceFunc "MEDecl"
-  --       MEComment{}          -> useTraceFunc traceFunc "MEComment"
+  --       MEDecl decl _        -> useTraceFunc traceFunc ("MEDecl " ++ intercalate "," (getDeclBindingNames decl))
+  --       MEComment (y, EpaLineComment str) -> useTraceFunc traceFunc ("MEComment " ++ show y ++ " " ++ str)
+  --       MEComment (y, _) -> useTraceFunc traceFunc ("MEComment " ++ show y ++ " _")
   --       MEWhitespace dp -> useTraceFunc traceFunc ("MEWhitespace " ++ show dp)
   --     rest
   --   )