ghc-lib-parser-0.20200401: compiler/GHC/Hs/Dump.hs
{-
(c) The University of Glasgow 2006
(c) The GRASP/AQUA Project, Glasgow University, 1992-1998
-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE ScopedTypeVariables #-}
-- | Contains a debug function to dump parts of the GHC.Hs AST. It uses a syb
-- traversal which falls back to displaying based on the constructor name, so
-- can be used to dump anything having a @Data.Data@ instance.
module GHC.Hs.Dump (
-- * Dumping ASTs
showAstData,
BlankSrcSpan(..),
) where
import GhcPrelude
import Data.Data hiding (Fixity)
import Bag
import GHC.Types.Basic
import FastString
import GHC.Types.Name.Set
import GHC.Types.Name
import GHC.Core.DataCon
import GHC.Types.SrcLoc
import GHC.Hs
import GHC.Types.Var
import GHC.Types.Module
import Outputable
import qualified Data.ByteString as B
data BlankSrcSpan = BlankSrcSpan | NoBlankSrcSpan
deriving (Eq,Show)
-- | Show a GHC syntax tree. This parameterised because it is also used for
-- comparing ASTs in ppr roundtripping tests, where the SrcSpan's are blanked
-- out, to avoid comparing locations, only structure
showAstData :: Data a => BlankSrcSpan -> a -> SDoc
showAstData b a0 = blankLine $$ showAstData' a0
where
showAstData' :: Data a => a -> SDoc
showAstData' =
generic
`ext1Q` list
`extQ` string `extQ` fastString `extQ` srcSpan
`extQ` lit `extQ` litr `extQ` litt
`extQ` bytestring
`extQ` name `extQ` occName `extQ` moduleName `extQ` var
`extQ` dataCon
`extQ` bagName `extQ` bagRdrName `extQ` bagVar `extQ` nameSet
`extQ` fixity
`ext2Q` located
where generic :: Data a => a -> SDoc
generic t = parens $ text (showConstr (toConstr t))
$$ vcat (gmapQ showAstData' t)
string :: String -> SDoc
string = text . normalize_newlines . show
fastString :: FastString -> SDoc
fastString s = braces $
text "FastString: "
<> text (normalize_newlines . show $ s)
bytestring :: B.ByteString -> SDoc
bytestring = text . normalize_newlines . show
list [] = brackets empty
list [x] = brackets (showAstData' x)
list (x1 : x2 : xs) = (text "[" <> showAstData' x1)
$$ go x2 xs
where
go y [] = text "," <> showAstData' y <> text "]"
go y1 (y2 : ys) = (text "," <> showAstData' y1) $$ go y2 ys
-- Eliminate word-size dependence
lit :: HsLit GhcPs -> SDoc
lit (HsWordPrim s x) = numericLit "HsWord{64}Prim" x s
lit (HsWord64Prim s x) = numericLit "HsWord{64}Prim" x s
lit (HsIntPrim s x) = numericLit "HsInt{64}Prim" x s
lit (HsInt64Prim s x) = numericLit "HsInt{64}Prim" x s
lit l = generic l
litr :: HsLit GhcRn -> SDoc
litr (HsWordPrim s x) = numericLit "HsWord{64}Prim" x s
litr (HsWord64Prim s x) = numericLit "HsWord{64}Prim" x s
litr (HsIntPrim s x) = numericLit "HsInt{64}Prim" x s
litr (HsInt64Prim s x) = numericLit "HsInt{64}Prim" x s
litr l = generic l
litt :: HsLit GhcTc -> SDoc
litt (HsWordPrim s x) = numericLit "HsWord{64}Prim" x s
litt (HsWord64Prim s x) = numericLit "HsWord{64}Prim" x s
litt (HsIntPrim s x) = numericLit "HsInt{64}Prim" x s
litt (HsInt64Prim s x) = numericLit "HsInt{64}Prim" x s
litt l = generic l
numericLit :: String -> Integer -> SourceText -> SDoc
numericLit tag x s = braces $ hsep [ text tag
, generic x
, generic s ]
name :: Name -> SDoc
name nm = braces $ text "Name: " <> ppr nm
occName n = braces $
text "OccName: "
<> text (occNameString n)
moduleName :: ModuleName -> SDoc
moduleName m = braces $ text "ModuleName: " <> ppr m
srcSpan :: SrcSpan -> SDoc
srcSpan ss = case b of
BlankSrcSpan -> text "{ ss }"
NoBlankSrcSpan -> braces $ char ' ' <>
(hang (ppr ss) 1
-- TODO: show annotations here
(text ""))
var :: Var -> SDoc
var v = braces $ text "Var: " <> ppr v
dataCon :: DataCon -> SDoc
dataCon c = braces $ text "DataCon: " <> ppr c
bagRdrName:: Bag (Located (HsBind GhcPs)) -> SDoc
bagRdrName bg = braces $
text "Bag(Located (HsBind GhcPs)):"
$$ (list . bagToList $ bg)
bagName :: Bag (Located (HsBind GhcRn)) -> SDoc
bagName bg = braces $
text "Bag(Located (HsBind Name)):"
$$ (list . bagToList $ bg)
bagVar :: Bag (Located (HsBind GhcTc)) -> SDoc
bagVar bg = braces $
text "Bag(Located (HsBind Var)):"
$$ (list . bagToList $ bg)
nameSet ns = braces $
text "NameSet:"
$$ (list . nameSetElemsStable $ ns)
fixity :: Fixity -> SDoc
fixity fx = braces $
text "Fixity: "
<> ppr fx
located :: (Data b,Data loc) => GenLocated loc b -> SDoc
located (L ss a) = parens $
case cast ss of
Just (s :: SrcSpan) ->
srcSpan s
Nothing -> text "nnnnnnnn"
$$ showAstData' a
normalize_newlines :: String -> String
normalize_newlines ('\\':'r':'\\':'n':xs) = '\\':'n':normalize_newlines xs
normalize_newlines (x:xs) = x:normalize_newlines xs
normalize_newlines [] = []
{-
************************************************************************
* *
* Copied from syb
* *
************************************************************************
-}
-- | The type constructor for queries
newtype Q q x = Q { unQ :: x -> q }
-- | Extend a generic query by a type-specific case
extQ :: ( Typeable a
, Typeable b
)
=> (a -> q)
-> (b -> q)
-> a
-> q
extQ f g a = maybe (f a) g (cast a)
-- | Type extension of queries for type constructors
ext1Q :: (Data d, Typeable t)
=> (d -> q)
-> (forall e. Data e => t e -> q)
-> d -> q
ext1Q def ext = unQ ((Q def) `ext1` (Q ext))
-- | Type extension of queries for type constructors
ext2Q :: (Data d, Typeable t)
=> (d -> q)
-> (forall d1 d2. (Data d1, Data d2) => t d1 d2 -> q)
-> d -> q
ext2Q def ext = unQ ((Q def) `ext2` (Q ext))
-- | Flexible type extension
ext1 :: (Data a, Typeable t)
=> c a
-> (forall d. Data d => c (t d))
-> c a
ext1 def ext = maybe def id (dataCast1 ext)
-- | Flexible type extension
ext2 :: (Data a, Typeable t)
=> c a
-> (forall d1 d2. (Data d1, Data d2) => c (t d1 d2))
-> c a
ext2 def ext = maybe def id (dataCast2 ext)