{-
(c) The GRASP/AQUA Project, Glasgow University, 1992-1998

-}

{-# LANGUAGE CPP #-}

-- | The @PrelInfo@ interface to the compiler's prelude knowledge.
--
-- This module serves as the central gathering point for names which the
-- compiler knows something about. This includes functions for,
--
--  * discerning whether a 'Name' is known-key
--
--  * given a 'Unique', looking up its corresponding known-key 'Name'
--
-- See Note [Known-key names] and Note [About wired-in things] for information
-- about the two types of prelude things in GHC.
--
module PrelInfo (
        -- * Known-key names
        isKnownKeyName,
        lookupKnownKeyName,
        lookupKnownNameInfo,

        -- ** Internal use
        -- | 'knownKeyNames' is exported to seed the original name cache only;
        -- if you find yourself wanting to look at it you might consider using
        -- 'lookupKnownKeyName' or 'isKnownKeyName'.
        knownKeyNames,

        -- * Miscellaneous
        wiredInIds, ghcPrimIds,
        primOpRules, builtinRules,

        ghcPrimExports,
        primOpId,

        -- * Random other things
        maybeCharLikeCon, maybeIntLikeCon,

        -- * Class categories
        isNumericClass, isStandardClass

    ) where

#include "HsVersions.h"

import GhcPrelude

import KnownUniques
import Unique           ( isValidKnownKeyUnique )

import ConLike          ( ConLike(..) )
import THNames          ( templateHaskellNames )
import PrelNames
import PrelRules
import Avail
import PrimOp
import DataCon
import BasicTypes
import Id
import Name
import NameEnv
import MkId
import Outputable
import TysPrim
import TysWiredIn
import HscTypes
import Class
import TyCon
import UniqFM
import Util
import TcTypeNats ( typeNatTyCons )

import Control.Applicative ((<|>))
import Data.List        ( intercalate )
import Data.Array
import Data.Maybe

{-
************************************************************************
*                                                                      *
\subsection[builtinNameInfo]{Lookup built-in names}
*                                                                      *
************************************************************************

Note [About wired-in things]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Wired-in things are Ids\/TyCons that are completely known to the compiler.
  They are global values in GHC, (e.g.  listTyCon :: TyCon).

* A wired in Name contains the thing itself inside the Name:
        see Name.wiredInNameTyThing_maybe
  (E.g. listTyConName contains listTyCon.

* The name cache is initialised with (the names of) all wired-in things
  (except tuples and sums; see Note [Known-])

* The type environment itself contains no wired in things. The type
  checker sees if the Name is wired in before looking up the name in
  the type environment.

* MkIface prunes out wired-in things before putting them in an interface file.
  So interface files never contain wired-in things.
-}


-- | This list is used to ensure that when you say "Prelude.map" in your source
-- code, or in an interface file, you get a Name with the correct known key (See
-- Note [Known-key names] in PrelNames)
knownKeyNames :: [Name]
knownKeyNames :: [Name]
knownKeyNames
  | Bool
debugIsOn
  , Just String
badNamesStr <- [Name] -> Maybe String
knownKeyNamesOkay [Name]
all_names
  = String -> [Name]
forall a. String -> a
panic (String
"badAllKnownKeyNames:\n" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
badNamesStr)
       -- NB: We can't use ppr here, because this is sometimes evaluated in a
       -- context where there are no DynFlags available, leading to a cryptic
       -- "<<details unavailable>>" error. (This seems to happen only in the
       -- stage 2 compiler, for reasons I [Richard] have no clue of.)
  | Bool
otherwise
  = [Name]
all_names
  where
    all_names :: [Name]
all_names =
      -- We exclude most tuples from this list—see
      -- Note [Infinite families of known-key names] in GHC.Builtin.Names.
      -- We make an exception for Unit (i.e., the boxed 1-tuple), since it does
      -- not use special syntax like other tuples.
      -- See Note [One-tuples] (Wrinkle: Make boxed one-tuple names have known keys)
      -- in GHC.Builtin.Types.
      TupleSort -> Arity -> Name
tupleTyConName TupleSort
BoxedTuple Arity
1 Name -> [Name] -> [Name]
forall a. a -> [a] -> [a]
: Boxity -> Arity -> Name
tupleDataConName Boxity
Boxed Arity
1 Name -> [Name] -> [Name]
forall a. a -> [a] -> [a]
:
      [[Name]] -> [Name]
forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat [ TyCon -> [Name]
wired_tycon_kk_names TyCon
funTyCon
             , (TyCon -> [Name]) -> [TyCon] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap TyCon -> [Name]
wired_tycon_kk_names [TyCon]
primTyCons
             , (TyCon -> [Name]) -> [TyCon] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap TyCon -> [Name]
wired_tycon_kk_names [TyCon]
wiredInTyCons
             , (TyCon -> [Name]) -> [TyCon] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap TyCon -> [Name]
wired_tycon_kk_names [TyCon]
typeNatTyCons
             , (Id -> Name) -> [Id] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map Id -> Name
idName [Id]
wiredInIds
             , (PrimOp -> Name) -> [PrimOp] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map (Id -> Name
idName (Id -> Name) -> (PrimOp -> Id) -> PrimOp -> Name
forall b c a. (b -> c) -> (a -> b) -> a -> c
. PrimOp -> Id
primOpId) [PrimOp]
allThePrimOps
             , (PrimOp -> Name) -> [PrimOp] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map (Id -> Name
idName (Id -> Name) -> (PrimOp -> Id) -> PrimOp -> Name
forall b c a. (b -> c) -> (a -> b) -> a -> c
. PrimOp -> Id
primOpWrapperId) [PrimOp]
allThePrimOps
             , [Name]
basicKnownKeyNames
             , [Name]
templateHaskellNames
             ]
    -- All of the names associated with a wired-in TyCon.
    -- This includes the TyCon itself, its DataCons and promoted TyCons.
    wired_tycon_kk_names :: TyCon -> [Name]
    wired_tycon_kk_names :: TyCon -> [Name]
wired_tycon_kk_names TyCon
tc =
        TyCon -> Name
tyConName TyCon
tc Name -> [Name] -> [Name]
forall a. a -> [a] -> [a]
: (TyCon -> [Name]
rep_names TyCon
tc [Name] -> [Name] -> [Name]
forall a. [a] -> [a] -> [a]
++ [Name]
implicits)
      where implicits :: [Name]
implicits = (TyThing -> [Name]) -> [TyThing] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap TyThing -> [Name]
thing_kk_names (TyCon -> [TyThing]
implicitTyConThings TyCon
tc)

    wired_datacon_kk_names :: DataCon -> [Name]
    wired_datacon_kk_names :: DataCon -> [Name]
wired_datacon_kk_names DataCon
dc =
      DataCon -> Name
dataConName DataCon
dc Name -> [Name] -> [Name]
forall a. a -> [a] -> [a]
: TyCon -> [Name]
rep_names (DataCon -> TyCon
promoteDataCon DataCon
dc)

    thing_kk_names :: TyThing -> [Name]
    thing_kk_names :: TyThing -> [Name]
thing_kk_names (ATyCon TyCon
tc)                 = TyCon -> [Name]
wired_tycon_kk_names TyCon
tc
    thing_kk_names (AConLike (RealDataCon DataCon
dc)) = DataCon -> [Name]
wired_datacon_kk_names DataCon
dc
    thing_kk_names TyThing
thing                       = [TyThing -> Name
forall a. NamedThing a => a -> Name
getName TyThing
thing]

    -- The TyConRepName for a known-key TyCon has a known key,
    -- but isn't itself an implicit thing.  Yurgh.
    -- NB: if any of the wired-in TyCons had record fields, the record
    --     field names would be in a similar situation.  Ditto class ops.
    --     But it happens that there aren't any
    rep_names :: TyCon -> [Name]
rep_names TyCon
tc = case TyCon -> Maybe Name
tyConRepName_maybe TyCon
tc of
                        Just Name
n  -> [Name
n]
                        Maybe Name
Nothing -> []

-- | Check the known-key names list of consistency.
knownKeyNamesOkay :: [Name] -> Maybe String
knownKeyNamesOkay :: [Name] -> Maybe String
knownKeyNamesOkay [Name]
all_names
  | ns :: [Name]
ns@(Name
_:[Name]
_) <- (Name -> Bool) -> [Name] -> [Name]
forall a. (a -> Bool) -> [a] -> [a]
filter (Bool -> Bool
not (Bool -> Bool) -> (Name -> Bool) -> Name -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Unique -> Bool
isValidKnownKeyUnique (Unique -> Bool) -> (Name -> Unique) -> Name -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Name -> Unique
forall a. Uniquable a => a -> Unique
getUnique) [Name]
all_names
  = String -> Maybe String
forall a. a -> Maybe a
Just (String -> Maybe String) -> String -> Maybe String
forall a b. (a -> b) -> a -> b
$ String
"    Out-of-range known-key uniques: ["
        String -> String -> String
forall a. [a] -> [a] -> [a]
++ String -> [String] -> String
forall a. [a] -> [[a]] -> [a]
intercalate String
", " ((Name -> String) -> [Name] -> [String]
forall a b. (a -> b) -> [a] -> [b]
map (OccName -> String
occNameString (OccName -> String) -> (Name -> OccName) -> Name -> String
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Name -> OccName
nameOccName) [Name]
ns) String -> String -> String
forall a. [a] -> [a] -> [a]
++
         String
"]"
  | [(Unique, [Name])] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [(Unique, [Name])]
badNamesPairs
  = Maybe String
forall a. Maybe a
Nothing
  | Bool
otherwise
  = String -> Maybe String
forall a. a -> Maybe a
Just String
badNamesStr
  where
    namesEnv :: NameEnv [Name]
namesEnv      = (NameEnv [Name] -> Name -> NameEnv [Name])
-> NameEnv [Name] -> [Name] -> NameEnv [Name]
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' (\NameEnv [Name]
m Name
n -> (Name -> [Name] -> [Name])
-> (Name -> [Name])
-> NameEnv [Name]
-> Name
-> Name
-> NameEnv [Name]
forall a b.
(a -> b -> b) -> (a -> b) -> NameEnv b -> Name -> a -> NameEnv b
extendNameEnv_Acc (:) Name -> [Name]
forall a. a -> [a]
singleton NameEnv [Name]
m Name
n Name
n)
                           NameEnv [Name]
forall elt. UniqFM elt
emptyUFM [Name]
all_names
    badNamesEnv :: NameEnv [Name]
badNamesEnv   = ([Name] -> Bool) -> NameEnv [Name] -> NameEnv [Name]
forall elt. (elt -> Bool) -> NameEnv elt -> NameEnv elt
filterNameEnv (\[Name]
ns -> [Name]
ns [Name] -> Arity -> Bool
forall a. [a] -> Arity -> Bool
`lengthExceeds` Arity
1) NameEnv [Name]
namesEnv
    badNamesPairs :: [(Unique, [Name])]
badNamesPairs = NameEnv [Name] -> [(Unique, [Name])]
forall elt. UniqFM elt -> [(Unique, elt)]
nonDetUFMToList NameEnv [Name]
badNamesEnv
      -- It's OK to use nonDetUFMToList here because the ordering only affects
      -- the message when we get a panic
    badNamesStrs :: [String]
badNamesStrs  = ((Unique, [Name]) -> String) -> [(Unique, [Name])] -> [String]
forall a b. (a -> b) -> [a] -> [b]
map (Unique, [Name]) -> String
forall a. Show a => (a, [Name]) -> String
pairToStr [(Unique, [Name])]
badNamesPairs
    badNamesStr :: String
badNamesStr   = [String] -> String
unlines [String]
badNamesStrs

    pairToStr :: (a, [Name]) -> String
pairToStr (a
uniq, [Name]
ns) = String
"        " String -> String -> String
forall a. [a] -> [a] -> [a]
++
                           a -> String
forall a. Show a => a -> String
show a
uniq String -> String -> String
forall a. [a] -> [a] -> [a]
++
                           String
": [" String -> String -> String
forall a. [a] -> [a] -> [a]
++
                           String -> [String] -> String
forall a. [a] -> [[a]] -> [a]
intercalate String
", " ((Name -> String) -> [Name] -> [String]
forall a b. (a -> b) -> [a] -> [b]
map (OccName -> String
occNameString (OccName -> String) -> (Name -> OccName) -> Name -> String
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Name -> OccName
nameOccName) [Name]
ns) String -> String -> String
forall a. [a] -> [a] -> [a]
++
                           String
"]"

-- | Given a 'Unique' lookup its associated 'Name' if it corresponds to a
-- known-key thing.
lookupKnownKeyName :: Unique -> Maybe Name
lookupKnownKeyName :: Unique -> Maybe Name
lookupKnownKeyName Unique
u =
    Unique -> Maybe Name
knownUniqueName Unique
u Maybe Name -> Maybe Name -> Maybe Name
forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> UniqFM Name -> Unique -> Maybe Name
forall key elt. Uniquable key => UniqFM elt -> key -> Maybe elt
lookupUFM UniqFM Name
knownKeysMap Unique
u

-- | Is a 'Name' known-key?
isKnownKeyName :: Name -> Bool
isKnownKeyName :: Name -> Bool
isKnownKeyName Name
n =
    Maybe Name -> Bool
forall a. Maybe a -> Bool
isJust (Unique -> Maybe Name
knownUniqueName (Unique -> Maybe Name) -> Unique -> Maybe Name
forall a b. (a -> b) -> a -> b
$ Name -> Unique
nameUnique Name
n) Bool -> Bool -> Bool
|| Name -> UniqFM Name -> Bool
forall key elt. Uniquable key => key -> UniqFM elt -> Bool
elemUFM Name
n UniqFM Name
knownKeysMap

knownKeysMap :: UniqFM Name
knownKeysMap :: UniqFM Name
knownKeysMap = [(Unique, Name)] -> UniqFM Name
forall key elt. Uniquable key => [(key, elt)] -> UniqFM elt
listToUFM [ (Name -> Unique
nameUnique Name
n, Name
n) | Name
n <- [Name]
knownKeyNames ]

-- | Given a 'Unique' lookup any associated arbitrary SDoc's to be displayed by
-- GHCi's ':info' command.
lookupKnownNameInfo :: Name -> SDoc
lookupKnownNameInfo :: Name -> SDoc
lookupKnownNameInfo Name
name = case NameEnv SDoc -> Name -> Maybe SDoc
forall a. NameEnv a -> Name -> Maybe a
lookupNameEnv NameEnv SDoc
knownNamesInfo Name
name of
    -- If we do find a doc, we add comment delimeters to make the output
    -- of ':info' valid Haskell.
    Maybe SDoc
Nothing  -> SDoc
empty
    Just SDoc
doc -> [SDoc] -> SDoc
vcat [String -> SDoc
text String
"{-", SDoc
doc, String -> SDoc
text String
"-}"]

-- A map from Uniques to SDocs, used in GHCi's ':info' command. (#12390)
knownNamesInfo :: NameEnv SDoc
knownNamesInfo :: NameEnv SDoc
knownNamesInfo = Name -> SDoc -> NameEnv SDoc
forall a. Name -> a -> NameEnv a
unitNameEnv Name
coercibleTyConName (SDoc -> NameEnv SDoc) -> SDoc -> NameEnv SDoc
forall a b. (a -> b) -> a -> b
$
    [SDoc] -> SDoc
vcat [ String -> SDoc
text String
"Coercible is a special constraint with custom solving rules."
         , String -> SDoc
text String
"It is not a class."
         , String -> SDoc
text String
"Please see section `The Coercible constraint`"
         , String -> SDoc
text String
"of the user's guide for details." ]

{-
We let a lot of "non-standard" values be visible, so that we can make
sense of them in interface pragmas. It's cool, though they all have
"non-standard" names, so they won't get past the parser in user code.

************************************************************************
*                                                                      *
                PrimOpIds
*                                                                      *
************************************************************************
-}

primOpIds :: Array Int Id
-- A cache of the PrimOp Ids, indexed by PrimOp tag
primOpIds :: Array Arity Id
primOpIds = (Arity, Arity) -> [(Arity, Id)] -> Array Arity Id
forall i e. Ix i => (i, i) -> [(i, e)] -> Array i e
array (Arity
1,Arity
maxPrimOpTag) [ (PrimOp -> Arity
primOpTag PrimOp
op, PrimOp -> Id
mkPrimOpId PrimOp
op)
                                   | PrimOp
op <- [PrimOp]
allThePrimOps ]

primOpId :: PrimOp -> Id
primOpId :: PrimOp -> Id
primOpId PrimOp
op = Array Arity Id
primOpIds Array Arity Id -> Arity -> Id
forall i e. Ix i => Array i e -> i -> e
! PrimOp -> Arity
primOpTag PrimOp
op

{-
************************************************************************
*                                                                      *
            Export lists for pseudo-modules (GHC.Prim)
*                                                                      *
************************************************************************

GHC.Prim "exports" all the primops and primitive types, some
wired-in Ids.
-}

ghcPrimExports :: [IfaceExport]
ghcPrimExports :: [IfaceExport]
ghcPrimExports
 = (Id -> IfaceExport) -> [Id] -> [IfaceExport]
forall a b. (a -> b) -> [a] -> [b]
map (Name -> IfaceExport
avail (Name -> IfaceExport) -> (Id -> Name) -> Id -> IfaceExport
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Id -> Name
idName) [Id]
ghcPrimIds [IfaceExport] -> [IfaceExport] -> [IfaceExport]
forall a. [a] -> [a] -> [a]
++
   (PrimOp -> IfaceExport) -> [PrimOp] -> [IfaceExport]
forall a b. (a -> b) -> [a] -> [b]
map (Name -> IfaceExport
avail (Name -> IfaceExport) -> (PrimOp -> Name) -> PrimOp -> IfaceExport
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Id -> Name
idName (Id -> Name) -> (PrimOp -> Id) -> PrimOp -> Name
forall b c a. (b -> c) -> (a -> b) -> a -> c
. PrimOp -> Id
primOpId) [PrimOp]
allThePrimOps [IfaceExport] -> [IfaceExport] -> [IfaceExport]
forall a. [a] -> [a] -> [a]
++
   [ Name -> [Name] -> [FieldLabel] -> IfaceExport
AvailTC Name
n [Name
n] []
   | TyCon
tc <- TyCon
funTyCon TyCon -> [TyCon] -> [TyCon]
forall a. a -> [a] -> [a]
: [TyCon]
exposedPrimTyCons, let n :: Name
n = TyCon -> Name
tyConName TyCon
tc  ]

{-
************************************************************************
*                                                                      *
            Built-in keys
*                                                                      *
************************************************************************

ToDo: make it do the ``like'' part properly (as in 0.26 and before).
-}

maybeCharLikeCon, maybeIntLikeCon :: DataCon -> Bool
maybeCharLikeCon :: DataCon -> Bool
maybeCharLikeCon DataCon
con = DataCon
con DataCon -> Unique -> Bool
forall a. Uniquable a => a -> Unique -> Bool
`hasKey` Unique
charDataConKey
maybeIntLikeCon :: DataCon -> Bool
maybeIntLikeCon  DataCon
con = DataCon
con DataCon -> Unique -> Bool
forall a. Uniquable a => a -> Unique -> Bool
`hasKey` Unique
intDataConKey

{-
************************************************************************
*                                                                      *
            Class predicates
*                                                                      *
************************************************************************
-}

isNumericClass, isStandardClass :: Class -> Bool

isNumericClass :: Class -> Bool
isNumericClass     Class
clas = Class -> Unique
classKey Class
clas Unique -> [Unique] -> Bool
forall a. Eq a => a -> [a] -> Bool
`is_elem` [Unique]
numericClassKeys
isStandardClass :: Class -> Bool
isStandardClass    Class
clas = Class -> Unique
classKey Class
clas Unique -> [Unique] -> Bool
forall a. Eq a => a -> [a] -> Bool
`is_elem` [Unique]
standardClassKeys

is_elem :: Eq a => a -> [a] -> Bool
is_elem :: a -> [a] -> Bool
is_elem = String -> a -> [a] -> Bool
forall a. Eq a => String -> a -> [a] -> Bool
isIn String
"is_X_Class"