aboutsummaryrefslogtreecommitdiff
path: root/haddock-api/src/Haddock/Interface/AttachInstances.hs
blob: d5b80888314b2d10e01edcd0ddf730f5a80bd543 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
{-# LANGUAGE MagicHash, BangPatterns #-}
{-# LANGUAGE TypeFamilies #-}
{-# OPTIONS_GHC -Wno-incomplete-record-updates #-}
{-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
-----------------------------------------------------------------------------
-- |
-- Module      :  Haddock.Interface.AttachInstances
-- Copyright   :  (c) Simon Marlow 2006,
--                    David Waern  2006-2009,
--                    Isaac Dupree 2009
-- License     :  BSD-like
--
-- Maintainer  :  haddock@projects.haskell.org
-- Stability   :  experimental
-- Portability :  portable
-----------------------------------------------------------------------------
module Haddock.Interface.AttachInstances (attachInstances) where


import Haddock.Types
import Haddock.Convert

import Control.Applicative ((<|>))
import Control.Arrow hiding ((<+>))
import Data.List (sortBy)
import Data.Ord (comparing)
import Data.Maybe ( maybeToList, mapMaybe, fromMaybe )
import qualified Data.Map as Map
import qualified Data.Set as Set

import GHC.Core.Class
import GHC.Driver.Session
import GHC.Core (isOrphan)
import GHC.Utils.Error
import GHC.Core.FamInstEnv
import GHC
import GHC.Core.InstEnv
import GHC.Unit.Module.Env ( ModuleSet, moduleSetElts )
import GHC.Utils.Monad (liftIO)
import GHC.Types.Name
import GHC.Types.Name.Env
import GHC.Utils.Outputable (text, sep, (<+>))
import GHC.Types.SrcLoc
import GHC.Core.TyCon
import GHC.Core.TyCo.Rep
import GHC.Builtin.Types.Prim( funTyConName )
import GHC.Types.Var hiding (varName)
import GHC.HsToCore.Docs

type ExportedNames = Set.Set Name
type Modules = Set.Set Module
type ExportInfo = (ExportedNames, Modules)

-- Also attaches fixities
attachInstances :: ExportInfo -> [Interface] -> InstIfaceMap -> ModuleSet -> Ghc [Interface]
attachInstances expInfo ifaces instIfaceMap mods = do
  (_msgs, mb_index) <- getNameToInstancesIndex (map ifaceMod ifaces) mods'
  mapM (attach $ fromMaybe emptyNameEnv mb_index) ifaces
  where
    mods' = Just (moduleSetElts mods)

    -- TODO: take an IfaceMap as input
    ifaceMap = Map.fromList [ (ifaceMod i, i) | i <- ifaces ]

    attach index iface = do

      let getInstDoc = findInstDoc iface ifaceMap instIfaceMap
          getFixity = findFixity iface ifaceMap instIfaceMap

      newItems <- mapM (attachToExportItem index expInfo getInstDoc getFixity)
                       (ifaceExportItems iface)
      let orphanInstances = attachOrphanInstances expInfo getInstDoc (ifaceInstances iface)
      return $ iface { ifaceExportItems = newItems
                     , ifaceOrphanInstances = orphanInstances
                     }

attachOrphanInstances
  :: ExportInfo
  -> (Name -> Maybe (MDoc Name))      -- ^ how to lookup the doc of an instance
  -> [ClsInst]                        -- ^ a list of orphan instances
  -> [DocInstance GhcRn]
attachOrphanInstances expInfo getInstDoc cls_instances =
  [ (synifyInstHead i, getInstDoc n, (L (getSrcSpan n) n), Nothing)
  | let is = [ (instanceSig i, getName i) | i <- cls_instances, isOrphan (is_orphan i) ]
  , (i@(_,_,cls,tys), n) <- sortBy (comparing $ first instHead) is
  , not $ isInstanceHidden expInfo cls tys
  ]


attachToExportItem
  :: NameEnv ([ClsInst], [FamInst])   -- ^ all instances (that we know of)
  -> ExportInfo
  -> (Name -> Maybe (MDoc Name))      -- ^ how to lookup the doc of an instance
  -> (Name -> Maybe Fixity)           -- ^ how to lookup a fixity
  -> ExportItem GhcRn
  -> Ghc (ExportItem GhcRn)
attachToExportItem index expInfo getInstDoc getFixity export =
  case attachFixities export of
    e@ExportDecl { expItemDecl = L eSpan (TyClD _ d) } -> do
      insts <-
        let mb_instances  = lookupNameEnv index (tcdName d)
            cls_instances = maybeToList mb_instances >>= fst
            fam_instances = maybeToList mb_instances >>= snd
            fam_insts = [ ( synFamInst
                          , getInstDoc n
                          , spanNameE n synFamInst (L eSpan (tcdName d))
                          , nameModule_maybe n
                          )
                        | i <- sortBy (comparing instFam) fam_instances
                        , let n = getName i
                        , not $ isNameHidden expInfo (fi_fam i)
                        , not $ any (isTypeHidden expInfo) (fi_tys i)
                        , let opaque = isTypeHidden expInfo (fi_rhs i)
                        , let synFamInst = synifyFamInst i opaque
                        ]
            cls_insts = [ ( synClsInst
                          , getInstDoc n
                          , spanName n synClsInst (L eSpan (tcdName d))
                          , nameModule_maybe n
                          )
                        | let is = [ (instanceSig i, getName i) | i <- cls_instances ]
                        , (i@(_,_,cls,tys), n) <- sortBy (comparing $ first instHead) is
                        , not $ isInstanceHidden expInfo cls tys
                        , let synClsInst = synifyInstHead i
                        ]
              -- fam_insts but with failing type fams filtered out
            cleanFamInsts = [ (fi, n, L l r, m) | (Right fi, n, L l (Right r), m) <- fam_insts ]
            famInstErrs = [ errm | (Left errm, _, _, _) <- fam_insts ]
        in do
          dfs <- getDynFlags
          let mkBug = (text "haddock-bug:" <+>) . text
          liftIO $ putMsg dfs (sep $ map mkBug famInstErrs)
          return $ cls_insts ++ cleanFamInsts
      return $ e { expItemInstances = insts }
    e -> return e
  where
    attachFixities e@ExportDecl{ expItemDecl = L _ d
                               , expItemPats = patsyns
                               , expItemSubDocs = subDocs
                               } = e { expItemFixities =
      nubByName fst $ expItemFixities e ++
      [ (n',f) | n <- getMainDeclBinder d
               , n' <- n : (map fst subDocs ++ patsyn_names)
               , f <- maybeToList (getFixity n')
      ] }
      where
        patsyn_names = concatMap (getMainDeclBinder . fst) patsyns

    attachFixities e = e
    -- spanName: attach the location to the name that is the same file as the instance location
    spanName s (InstHead { ihdClsName = clsn }) (L instL instn) =
        let s1 = getSrcSpan s
            sn = if srcSpanFileName_maybe s1 == srcSpanFileName_maybe instL
                    then instn
                    else clsn
        in L (getSrcSpan s) sn
    -- spanName on Either
    spanNameE s (Left e) _ =  L (getSrcSpan s) (Left e)
    spanNameE s (Right ok) linst =
      let L l r = spanName s ok linst
      in L l (Right r)

-- | Lookup the doc associated with a certain instance
findInstDoc :: Interface -> IfaceMap -> InstIfaceMap -> Name -> Maybe (MDoc Name)
findInstDoc iface ifaceMap instIfaceMap = \name ->
  (Map.lookup name . ifaceDocMap $ iface) <|>
  (Map.lookup name . ifaceDocMap =<< Map.lookup (nameModule name) ifaceMap) <|>
  (Map.lookup name . instDocMap =<< Map.lookup (nameModule name) instIfaceMap)

-- | Lookup the fixity associated with a certain name
findFixity :: Interface -> IfaceMap -> InstIfaceMap -> Name -> Maybe Fixity
findFixity iface ifaceMap instIfaceMap = \name ->
  (Map.lookup name . ifaceFixMap $ iface) <|>
  (Map.lookup name . ifaceFixMap =<< Map.lookup (nameModule name) ifaceMap) <|>
  (Map.lookup name . instFixMap =<< Map.lookup (nameModule name) instIfaceMap)


--------------------------------------------------------------------------------
-- Collecting and sorting instances
--------------------------------------------------------------------------------

-- | Stable name for stable comparisons. GHC's `Name` uses unstable
-- ordering based on their `Unique`'s.
newtype SName = SName Name

instance Eq SName where
  SName n1 == SName n2 = n1 `stableNameCmp` n2 == EQ

instance Ord SName where
  SName n1 `compare` SName n2 = n1 `stableNameCmp` n2

-- | Simplified type for sorting types, ignoring qualification (not visible
-- in Haddock output) and unifying special tycons with normal ones.
-- For the benefit of the user (looks nice and predictable) and the
-- tests (which prefer output to be deterministic).
data SimpleType = SimpleType SName [SimpleType]
                | SimpleTyLit TyLit
                  deriving (Eq,Ord)


instHead :: ([TyVar], [PredType], Class, [Type]) -> ([Int], SName, [SimpleType])
instHead (_, _, cls, args)
  = (map argCount args, SName (className cls), map simplify args)

argCount :: Type -> Int
argCount (AppTy t _)     = argCount t + 1
argCount (TyConApp _ ts) = length ts
argCount (FunTy _ _ _ _) = 2
argCount (ForAllTy _ t)  = argCount t
argCount (CastTy t _)    = argCount t
argCount _ = 0

simplify :: Type -> SimpleType
simplify (FunTy _ _ t1 t2)  = SimpleType (SName funTyConName) [simplify t1, simplify t2]
simplify (ForAllTy _ t) = simplify t
simplify (AppTy t1 t2) = SimpleType s (ts ++ maybeToList (simplify_maybe t2))
  where (SimpleType s ts) = simplify t1
simplify (TyVarTy v) = SimpleType (SName (tyVarName v)) []
simplify (TyConApp tc ts) = SimpleType (SName (tyConName tc))
                                       (mapMaybe simplify_maybe ts)
simplify (LitTy l) = SimpleTyLit l
simplify (CastTy ty _) = simplify ty
simplify (CoercionTy _) = error "simplify:Coercion"

simplify_maybe :: Type -> Maybe SimpleType
simplify_maybe (CoercionTy {}) = Nothing
simplify_maybe ty              = Just (simplify ty)

-- Used for sorting
instFam :: FamInst -> ([Int], SName, [SimpleType], Int, SimpleType)
instFam FamInst { fi_fam = n, fi_tys = ts, fi_rhs = t }
  = (map argCount ts, SName n, map simplify ts, argCount t, simplify t)


--------------------------------------------------------------------------------
-- Filtering hidden instances
--------------------------------------------------------------------------------

-- | A class or data type is hidden iff
--
-- * it is defined in one of the modules that are being processed
--
-- * and it is not exported by any non-hidden module
isNameHidden :: ExportInfo -> Name -> Bool
isNameHidden (names, modules) name =
  nameModule name `Set.member` modules &&
  not (name `Set.member` names)

-- | We say that an instance is «hidden» iff its class or any (part)
-- of its type(s) is hidden.
isInstanceHidden :: ExportInfo -> Class -> [Type] -> Bool
isInstanceHidden expInfo cls tys =
    instClassHidden || instTypeHidden
  where
    instClassHidden :: Bool
    instClassHidden = isNameHidden expInfo $ getName cls

    instTypeHidden :: Bool
    instTypeHidden = any (isTypeHidden expInfo) tys

isTypeHidden :: ExportInfo -> Type -> Bool
isTypeHidden expInfo = typeHidden
  where
    typeHidden :: Type -> Bool
    typeHidden t =
      case t of
        TyVarTy {} -> False
        AppTy t1 t2 -> typeHidden t1 || typeHidden t2
        FunTy _ _ t1 t2 -> typeHidden t1 || typeHidden t2
        TyConApp tcon args -> nameHidden (getName tcon) || any typeHidden args
        ForAllTy bndr ty -> typeHidden (tyVarKind (binderVar bndr)) || typeHidden ty
        LitTy _ -> False
        CastTy ty _ -> typeHidden ty
        CoercionTy {} -> False

    nameHidden :: Name -> Bool
    nameHidden = isNameHidden expInfo