TTG: Move ImpExp client-independent bits to L.H.S.ImpExp

Move the GHC-independent definitions from GHC.Hs.ImpExp to
Language.Haskell.Syntax.ImpExp with the required TTG extension fields
such as to keep the AST independent from GHC.

This is progress towards having the haskell-syntax package, as described
in #21592

Bumps haddock submodule

4 files changed, 209 insertions, 2 deletions

diff --git a/compiler/Language/Haskell/Syntax/Decls.hs b/compiler/Language/Haskell/Syntax/Decls.hs
index 303105e3d4..da5265a144 100644
--- a/compiler/Language/Haskell/Syntax/Decls.hs
+++ b/compiler/Language/Haskell/Syntax/Decls.hs
@@ -100,7 +100,7 @@ import {-# SOURCE #-} Language.Haskell.Syntax.Expr
 
 import Language.Haskell.Syntax.Binds
 import Language.Haskell.Syntax.Type
-import GHC.Hs.Doc
+import GHC.Hs.Doc -- ROMES:TODO Discuss in #21592 whether this is parsed AST or base AST
 import GHC.Core.TyCon
 import GHC.Types.Basic
 import GHC.Types.ForeignCall
diff --git a/compiler/Language/Haskell/Syntax/Extension.hs b/compiler/Language/Haskell/Syntax/Extension.hs
index f63ca09b30..6312681f52 100644
--- a/compiler/Language/Haskell/Syntax/Extension.hs
+++ b/compiler/Language/Haskell/Syntax/Extension.hs
@@ -399,7 +399,7 @@ type family XXInjectivityAnn  x
 -- =====================================================================
 -- Type families for the HsModule extension points
 
-type family XModule x
+type family XCModule x
 type family XXModule x
 
 -- =====================================================================
@@ -686,6 +686,7 @@ type family XXFieldOcc x
 -- ImportDecl type families
 type family XCImportDecl       x
 type family XXImportDecl       x
+type family ImportDeclPkgQual  x -- stores the package qualifier in an import statement
 
 -- -------------------------------------
 -- IE type families
@@ -700,6 +701,13 @@ type family XIEDocNamed        x
 type family XXIE               x
 
 -- -------------------------------------
+-- IEWrappedName type families
+type family XIEName p
+type family XIEPattern p
+type family XIEType p
+type family XXIEWrappedName p
+
+
 
 -- =====================================================================
 -- Misc
diff --git a/compiler/Language/Haskell/Syntax/ImpExp.hs b/compiler/Language/Haskell/Syntax/ImpExp.hs
new file mode 100644
index 0000000000..7e529701c4
--- /dev/null
+++ b/compiler/Language/Haskell/Syntax/ImpExp.hs
@@ -0,0 +1,177 @@
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+module Language.Haskell.Syntax.ImpExp where
+
+import Language.Haskell.Syntax.Extension
+
+import Data.Eq (Eq)
+import Data.Ord (Ord)
+import Text.Show (Show)
+import Data.Data (Data)
+import Data.Bool (Bool)
+import Data.Maybe (Maybe)
+import Data.String (String)
+import Data.Int (Int)
+
+import GHC.Hs.Doc -- ROMES:TODO Discuss in #21592 whether this is parsed AST or base AST
+import GHC.Data.FastString
+
+{-
+************************************************************************
+*                                                                      *
+Import and export declaration lists
+*                                                                      *
+************************************************************************
+
+One per import declaration in a module.
+-}
+
+-- | A ModuleName is essentially a simple string, e.g. @Data.List@.
+newtype ModuleName = ModuleName FastString deriving Show
+
+-- | Located Import Declaration
+type LImportDecl pass = XRec pass (ImportDecl pass)
+        -- ^ When in a list this may have
+        --
+        --  - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnSemi'
+
+        -- For details on above see Note [exact print annotations] in GHC.Parser.Annotation
+
+-- | If/how an import is 'qualified'.
+data ImportDeclQualifiedStyle
+  = QualifiedPre  -- ^ 'qualified' appears in prepositive position.
+  | QualifiedPost -- ^ 'qualified' appears in postpositive position.
+  | NotQualified  -- ^ Not qualified.
+  deriving Data
+
+-- | Indicates whether a module name is referring to a boot interface (hs-boot
+-- file) or regular module (hs file). We need to treat boot modules specially
+-- when building compilation graphs, since they break cycles. Regular source
+-- files and signature files are treated equivalently.
+data IsBootInterface = NotBoot | IsBoot
+    deriving (Eq, Ord, Show, Data)
+
+-- | Import Declaration
+--
+-- A single Haskell @import@ declaration.
+data ImportDecl pass
+  = ImportDecl {
+      ideclExt        :: XCImportDecl pass,
+      ideclName       :: XRec pass ModuleName, -- ^ Module name.
+      ideclPkgQual    :: ImportDeclPkgQual pass,  -- ^ Package qualifier.
+      ideclSource     :: IsBootInterface,      -- ^ IsBoot <=> {-\# SOURCE \#-} import
+      ideclSafe       :: Bool,          -- ^ True => safe import
+      ideclQualified  :: ImportDeclQualifiedStyle, -- ^ If/how the import is qualified.
+      ideclAs         :: Maybe (XRec pass ModuleName),  -- ^ as Module
+      ideclImportList :: Maybe (ImportListInterpretation, XRec pass [LIE pass])
+                                       -- ^ Explicit import list (EverythingBut => hiding, names)
+    }
+  | XImportDecl !(XXImportDecl pass)
+     -- ^
+     --  'GHC.Parser.Annotation.AnnKeywordId's
+     --
+     --  - 'GHC.Parser.Annotation.AnnImport'
+     --
+     --  - 'GHC.Parser.Annotation.AnnOpen', 'GHC.Parser.Annotation.AnnClose' for ideclSource
+     --
+     --  - 'GHC.Parser.Annotation.AnnSafe','GHC.Parser.Annotation.AnnQualified',
+     --    'GHC.Parser.Annotation.AnnPackageName','GHC.Parser.Annotation.AnnAs',
+     --    'GHC.Parser.Annotation.AnnVal'
+     --
+     --  - 'GHC.Parser.Annotation.AnnHiding','GHC.Parser.Annotation.AnnOpen',
+     --    'GHC.Parser.Annotation.AnnClose' attached
+     --     to location in ideclImportList
+
+     -- For details on above see Note [exact print annotations] in GHC.Parser.Annotation
+
+-- | Whether the import list is exactly what to import, or whether `hiding` was
+-- used, and therefore everything but what was listed should be imported
+data ImportListInterpretation = Exactly | EverythingBut
+    deriving (Eq, Data)
+
+-- | Located Import or Export
+type LIE pass = XRec pass (IE pass)
+        -- ^ When in a list this may have
+        --
+        --  - 'GHC.Parser.Annotation.AnnKeywordId' : 'GHC.Parser.Annotation.AnnComma'
+
+        -- For details on above see Note [exact print annotations] in GHC.Parser.Annotation
+
+-- | Imported or exported entity.
+data IE pass
+  = IEVar       (XIEVar pass) (LIEWrappedName pass)
+        -- ^ Imported or Exported Variable
+
+  | IEThingAbs  (XIEThingAbs pass) (LIEWrappedName pass)
+        -- ^ Imported or exported Thing with Absent list
+        --
+        -- The thing is a Class/Type (can't tell)
+        --  - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnPattern',
+        --             'GHC.Parser.Annotation.AnnType','GHC.Parser.Annotation.AnnVal'
+
+        -- For details on above see Note [exact print annotations] in GHC.Parser.Annotation
+        -- See Note [Located RdrNames] in GHC.Hs.Expr
+  | IEThingAll  (XIEThingAll pass) (LIEWrappedName pass)
+        -- ^ Imported or exported Thing with All imported or exported
+        --
+        -- The thing is a Class/Type and the All refers to methods/constructors
+        --
+        -- - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnOpen',
+        --       'GHC.Parser.Annotation.AnnDotdot','GHC.Parser.Annotation.AnnClose',
+        --                                 'GHC.Parser.Annotation.AnnType'
+
+        -- For details on above see Note [exact print annotations] in GHC.Parser.Annotation
+        -- See Note [Located RdrNames] in GHC.Hs.Expr
+
+  | IEThingWith (XIEThingWith pass)
+                (LIEWrappedName pass)
+                IEWildcard
+                [LIEWrappedName pass]
+        -- ^ Imported or exported Thing With given imported or exported
+        --
+        -- The thing is a Class/Type and the imported or exported things are
+        -- methods/constructors and record fields; see Note [IEThingWith]
+        -- - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnOpen',
+        --                                   'GHC.Parser.Annotation.AnnClose',
+        --                                   'GHC.Parser.Annotation.AnnComma',
+        --                                   'GHC.Parser.Annotation.AnnType'
+
+        -- For details on above see Note [exact print annotations] in GHC.Parser.Annotation
+  | IEModuleContents  (XIEModuleContents pass) (XRec pass ModuleName)
+        -- ^ Imported or exported module contents
+        --
+        -- (Export Only)
+        --
+        -- - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnModule'
+
+        -- For details on above see Note [exact print annotations] in GHC.Parser.Annotation
+  | IEGroup             (XIEGroup pass) Int (LHsDoc pass) -- ^ Doc section heading
+  | IEDoc               (XIEDoc pass) (LHsDoc pass)       -- ^ Some documentation
+  | IEDocNamed          (XIEDocNamed pass) String    -- ^ Reference to named doc
+  | XIE !(XXIE pass)
+
+-- | Wildcard in an import or export sublist, like the @..@ in
+-- @import Mod ( T(Mk1, Mk2, ..) )@.
+data IEWildcard
+  = NoIEWildcard   -- ^ no wildcard in this list
+  | IEWildcard Int -- ^ wildcard after the given \# of items in this list
+                   -- The @Int@ is in the range [0..n], where n is the length
+                   -- of the list.
+  deriving (Eq, Data)
+
+-- | A name in an import or export specification which may have
+-- adornments. Used primarily for accurate pretty printing of
+-- ParsedSource, and API Annotation placement. The
+-- 'GHC.Parser.Annotation' is the location of the adornment in
+-- the original source.
+data IEWrappedName p
+  = IEName    (XIEName p)    (LIdP p)  -- ^ no extra
+  | IEPattern (XIEPattern p) (LIdP p)  -- ^ pattern X
+  | IEType    (XIEType p)    (LIdP p)  -- ^ type (:+:)
+  | XIEWrappedName !(XXIEWrappedName p)
+
+-- | Located name with possible adornment
+-- - 'GHC.Parser.Annotation.AnnKeywordId's : 'GHC.Parser.Annotation.AnnType',
+--         'GHC.Parser.Annotation.AnnPattern'
+type LIEWrappedName p = XRec p (IEWrappedName p)
+-- For details on above see Note [exact print annotations] in GHC.Parser.Annotation
diff --git a/compiler/Language/Haskell/Syntax/ImpExp.hs-boot b/compiler/Language/Haskell/Syntax/ImpExp.hs-boot
new file mode 100644
index 0000000000..9cc78600b8
--- /dev/null
+++ b/compiler/Language/Haskell/Syntax/ImpExp.hs-boot
@@ -0,0 +1,22 @@
+module Language.Haskell.Syntax.ImpExp where
+
+import GHC.Data.FastString
+
+import Data.Eq
+import Data.Ord
+import Text.Show
+import Data.Data
+
+-- This boot file should be short lived: As soon as the dependency on
+-- `GHC.Hs.Doc` is gone we'll no longer have cycles and can get rid this file.
+
+data IsBootInterface = NotBoot | IsBoot
+
+instance Eq IsBootInterface
+instance Ord IsBootInterface
+instance Show IsBootInterface
+instance Data IsBootInterface
+
+newtype ModuleName = ModuleName FastString
+
+instance Show ModuleName