ghc-mod/Language/Haskell/GhcMod/DynFlagsTH.hs
2016-02-14 10:10:26 +01:00

122 lines
4.2 KiB
Haskell

-- ghc-mod: Making Haskell development *more* fun
-- Copyright (C) 2015 Daniel Gröber <dxld ÄT darkboxed DOT org>
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU Affero General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU Affero General Public License for more details.
--
-- You should have received a copy of the GNU Affero General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
{-# LANGUAGE CPP, TemplateHaskell #-}
module Language.Haskell.GhcMod.DynFlagsTH where
import Language.Haskell.TH.Syntax
import Control.Applicative
import Data.Maybe
import Data.Generics.Aliases
import Data.Generics.Schemes
import DynFlags
import Prelude
deriveEqDynFlags :: Q [Dec] -> Q [Dec]
deriveEqDynFlags qds = do
~(TyConI (DataD [] _ [] [ctor] _ )) <- reify ''DynFlags
let ~(RecC _ fs) = ctor
a <- newName "a"
b <- newName "b"
e <- AppE (VarE 'and) . ListE <$> sequence (catMaybes $ map (eq a b) fs)
tysig@(SigD n _) :_ <- qds
return $ [tysig, FunD n [Clause [VarP a, VarP b] (NormalB e) []]]
where
eq :: Name -> Name -> (Name, Strict, Type) -> Maybe (Q Exp)
eq a b (fn@(Name (OccName fon) _), _, ft)
| not (isUneqable || isIgnored) = Just expr
| otherwise = Nothing
where
isUneqable = everything (||) (mkQ False hasUnEqable) ft
hasUnEqable ArrowT = True
hasUnEqable (ConT (Name (OccName on) _))
| any (==on) ignoredTypeNames = True
| any (==on) ignoredTypeOccNames = True
hasUnEqable _ = False
isIgnored = fon `elem` ignoredNames
ignoredNames = [ "pkgDatabase" -- 7.8
#if __GLASGOW_HASKELL__ <= 706
, "ways" -- 'Ways' is not exported :/
#endif
]
ignoredTypeNames =
[ "LogAction"
, "PackageState"
, "Hooks"
, "FlushOut"
, "FlushErr"
, "Settings" -- I think these can't cange at runtime
]
ignoredTypeOccNames = [ "OnOff" ]
fa = AppE (VarE fn) (VarE a)
fb = AppE (VarE fn) (VarE b)
expr =
case fon of
"rtsOptsEnabled" -> do
eqfn <- [| let eqfn RtsOptsNone RtsOptsNone = True
eqfn RtsOptsSafeOnly RtsOptsSafeOnly = True
eqfn RtsOptsAll RtsOptsAll = True
eqfn _ _ = False
in eqfn
|]
return $ AppE (AppE eqfn fa) fb
#if __GLASGOW_HASKELL__ >= 710
"sigOf" -> do
eqfn <- [| let eqfn NotSigOf NotSigOf = True
eqfn (SigOf a') (SigOf b') = a' == b'
eqfn (SigOfMap a') (SigOfMap b') = a' == b'
eqfn _ _ = False
in eqfn
|]
return $ AppE (AppE eqfn fa) fb
#endif
#if __GLASGOW_HASKELL <= 706
"profAuto" -> do
eqfn <- [| let eqfn NoProfAuto NoProfAuto = True
eqfn ProfAutoAll ProfAutoAll = True
eqfn ProfAutoTop ProfAutoTop = True
eqfn ProfAutoExports ProfAutoExports = True
eqfn ProfAutoCalls ProfAutoCalls = True
eqfn _ _ = False
in eqfn
|]
return $ AppE (AppE eqfn fa) fb
#endif
#if __GLASGOW_HASKELL__ >= 706
"language" -> do
eqfn <- [| let eqfn (Just Haskell98) (Just Haskell98) = True
eqfn (Just Haskell2010) (Just Haskell2010) = True
eqfn _ _ = False
in eqfn
|]
return $ AppE (AppE eqfn fa) fb
#endif
_ ->
return $ InfixE (Just fa) (VarE '(==)) (Just fb)