{- (c) The University of Glasgow 2006 (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 \section[Name]{@Name@: to transmit name info from renamer to typechecker} -} {-# LANGUAGE RecordWildCards #-} -- | -- #name_types# -- GHC uses several kinds of name internally: -- -- * 'OccName.OccName': see "OccName#name_types" -- -- * 'RdrName.RdrName': see "RdrName#name_types" -- -- * 'Name.Name' is the type of names that have had their scoping and binding resolved. They -- have an 'OccName.OccName' but also a 'Unique.Unique' that disambiguates Names that have -- the same 'OccName.OccName' and indeed is used for all 'Name.Name' comparison. Names -- also contain information about where they originated from, see "Name#name_sorts" -- -- * 'Id.Id': see "Id#name_types" -- -- * 'Var.Var': see "Var#name_types" -- -- #name_sorts# -- Names are one of: -- -- * External, if they name things declared in other modules. Some external -- Names are wired in, i.e. they name primitives defined in the compiler itself -- -- * Internal, if they name things in the module being compiled. Some internal -- Names are system names, if they are names manufactured by the compiler module Name ( -- * The main types Name, -- Abstract BuiltInSyntax(..), -- ** Creating 'Name's mkSystemName, mkSystemNameAt, mkInternalName, mkClonedInternalName, mkDerivedInternalName, mkSystemVarName, mkSysTvName, mkFCallName, mkExternalName, mkWiredInName, -- ** Manipulating and deconstructing 'Name's nameUnique, setNameUnique, nameOccName, nameModule, nameModule_maybe, setNameLoc, tidyNameOcc, localiseName, mkLocalisedOccName, nameSrcLoc, nameSrcSpan, pprNameDefnLoc, pprDefinedAt, -- ** Predicates on 'Name's isSystemName, isInternalName, isExternalName, isTyVarName, isTyConName, isDataConName, isValName, isVarName, isWiredInName, isBuiltInSyntax, isHoleName, wiredInNameTyThing_maybe, nameIsLocalOrFrom, nameIsHomePackage, nameIsHomePackageImport, nameIsFromExternalPackage, stableNameCmp, -- * Class 'NamedThing' and overloaded friends NamedThing(..), getSrcLoc, getSrcSpan, getOccString, getOccFS, pprInfixName, pprPrefixName, pprModulePrefix, nameStableString, -- Re-export the OccName stuff module OccName ) where import {-# SOURCE #-} TyCoRep( TyThing ) import {-# SOURCE #-} PrelNames( starKindTyConKey, unicodeStarKindTyConKey ) import OccName import Module import SrcLoc import Unique import Util import Maybes import Binary import DynFlags import FastString import Outputable import Control.DeepSeq import Data.Data {- ************************************************************************ * * \subsection[Name-datatype]{The @Name@ datatype, and name construction} * * ************************************************************************ -} -- | A unique, unambiguous name for something, containing information about where -- that thing originated. data Name = Name { n_sort :: NameSort, -- What sort of name it is n_occ :: !OccName, -- Its occurrence name n_uniq :: {-# UNPACK #-} !Int, n_loc :: !SrcSpan -- Definition site } -- NOTE: we make the n_loc field strict to eliminate some potential -- (and real!) space leaks, due to the fact that we don't look at -- the SrcLoc in a Name all that often. data NameSort = External Module | WiredIn Module TyThing BuiltInSyntax -- A variant of External, for wired-in things | Internal -- A user-defined Id or TyVar -- defined in the module being compiled | System -- A system-defined Id or TyVar. Typically the -- OccName is very uninformative (like 's') instance Outputable NameSort where ppr (External _) = text "external" ppr (WiredIn _ _ _) = text "wired-in" ppr Internal = text "internal" ppr System = text "system" instance NFData Name where rnf Name{..} = rnf n_sort instance NFData NameSort where rnf (External m) = rnf m rnf (WiredIn m t b) = rnf m `seq` t `seq` b `seq` () -- XXX this is a *lie*, we're not going to rnf the TyThing, but -- since the TyThings for WiredIn Names are all static they can't -- be hiding space leaks or errors. rnf Internal = () rnf System = () -- | BuiltInSyntax is for things like @(:)@, @[]@ and tuples, -- which have special syntactic forms. They aren't in scope -- as such. data BuiltInSyntax = BuiltInSyntax | UserSyntax {- Notes about the NameSorts: 1. Initially, top-level Ids (including locally-defined ones) get External names, and all other local Ids get Internal names 2. In any invocation of GHC, an External Name for "M.x" has one and only one unique. This unique association is ensured via the Name Cache; see Note [The Name Cache] in IfaceEnv. 3. Things with a External name are given C static labels, so they finally appear in the .o file's symbol table. They appear in the symbol table in the form M.n. If originally-local things have this property they must be made @External@ first. 4. In the tidy-core phase, a External that is not visible to an importer is changed to Internal, and a Internal that is visible is changed to External 5. A System Name differs in the following ways: a) has unique attached when printing dumps b) unifier eliminates sys tyvars in favour of user provs where possible Before anything gets printed in interface files or output code, it's fed through a 'tidy' processor, which zaps the OccNames to have unique names; and converts all sys-locals to user locals If any desugarer sys-locals have survived that far, they get changed to "ds1", "ds2", etc. Built-in syntax => It's a syntactic form, not "in scope" (e.g. []) Wired-in thing => The thing (Id, TyCon) is fully known to the compiler, not read from an interface file. E.g. Bool, True, Int, Float, and many others All built-in syntax is for wired-in things. -} instance HasOccName Name where occName = nameOccName nameUnique :: Name -> Unique nameOccName :: Name -> OccName nameModule :: Name -> Module nameSrcLoc :: Name -> SrcLoc nameSrcSpan :: Name -> SrcSpan nameUnique name = mkUniqueGrimily (n_uniq name) nameOccName name = n_occ name nameSrcLoc name = srcSpanStart (n_loc name) nameSrcSpan name = n_loc name {- ************************************************************************ * * \subsection{Predicates on names} * * ************************************************************************ -} isInternalName :: Name -> Bool isExternalName :: Name -> Bool isSystemName :: Name -> Bool isWiredInName :: Name -> Bool isWiredInName (Name {n_sort = WiredIn _ _ _}) = True isWiredInName _ = False wiredInNameTyThing_maybe :: Name -> Maybe TyThing wiredInNameTyThing_maybe (Name {n_sort = WiredIn _ thing _}) = Just thing wiredInNameTyThing_maybe _ = Nothing isBuiltInSyntax :: Name -> Bool isBuiltInSyntax (Name {n_sort = WiredIn _ _ BuiltInSyntax}) = True isBuiltInSyntax _ = False isExternalName (Name {n_sort = External _}) = True isExternalName (Name {n_sort = WiredIn _ _ _}) = True isExternalName _ = False isInternalName name = not (isExternalName name) isHoleName :: Name -> Bool isHoleName = isHoleModule . nameModule nameModule name = nameModule_maybe name `orElse` pprPanic "nameModule" (ppr (n_sort name) <+> ppr name) nameModule_maybe :: Name -> Maybe Module nameModule_maybe (Name { n_sort = External mod}) = Just mod nameModule_maybe (Name { n_sort = WiredIn mod _ _}) = Just mod nameModule_maybe _ = Nothing nameIsLocalOrFrom :: Module -> Name -> Bool -- ^ Returns True if the name is -- (a) Internal -- (b) External but from the specified module -- (c) External but from the 'interactive' package -- -- The key idea is that -- False means: the entity is defined in some other module -- you can find the details (type, fixity, instances) -- in some interface file -- those details will be stored in the EPT or HPT -- -- True means: the entity is defined in this module or earlier in -- the GHCi session -- you can find details (type, fixity, instances) in the -- TcGblEnv or TcLclEnv -- -- The isInteractiveModule part is because successive interactions of a GCHi session -- each give rise to a fresh module (Ghci1, Ghci2, etc), but they all come -- from the magic 'interactive' package; and all the details are kept in the -- TcLclEnv, TcGblEnv, NOT in the HPT or EPT. -- See Note [The interactive package] in HscTypes nameIsLocalOrFrom from name | Just mod <- nameModule_maybe name = from == mod || isInteractiveModule mod | otherwise = True nameIsHomePackage :: Module -> Name -> Bool -- True if the Name is defined in module of this package nameIsHomePackage this_mod = \nm -> case n_sort nm of External nm_mod -> moduleUnitId nm_mod == this_pkg WiredIn nm_mod _ _ -> moduleUnitId nm_mod == this_pkg Internal -> True System -> False where this_pkg = moduleUnitId this_mod nameIsHomePackageImport :: Module -> Name -> Bool -- True if the Name is defined in module of this package -- /other than/ the this_mod nameIsHomePackageImport this_mod = \nm -> case nameModule_maybe nm of Nothing -> False Just nm_mod -> nm_mod /= this_mod && moduleUnitId nm_mod == this_pkg where this_pkg = moduleUnitId this_mod -- | Returns True if the Name comes from some other package: neither this -- pacakge nor the interactive package. nameIsFromExternalPackage :: UnitId -> Name -> Bool nameIsFromExternalPackage this_pkg name | Just mod <- nameModule_maybe name , moduleUnitId mod /= this_pkg -- Not this package , not (isInteractiveModule mod) -- Not the 'interactive' package = True | otherwise = False isTyVarName :: Name -> Bool isTyVarName name = isTvOcc (nameOccName name) isTyConName :: Name -> Bool isTyConName name = isTcOcc (nameOccName name) isDataConName :: Name -> Bool isDataConName name = isDataOcc (nameOccName name) isValName :: Name -> Bool isValName name = isValOcc (nameOccName name) isVarName :: Name -> Bool isVarName = isVarOcc . nameOccName isSystemName (Name {n_sort = System}) = True isSystemName _ = False {- ************************************************************************ * * \subsection{Making names} * * ************************************************************************ -} -- | Create a name which is (for now at least) local to the current module and hence -- does not need a 'Module' to disambiguate it from other 'Name's mkInternalName :: Unique -> OccName -> SrcSpan -> Name mkInternalName uniq occ loc = Name { n_uniq = getKey uniq , n_sort = Internal , n_occ = occ , n_loc = loc } -- NB: You might worry that after lots of huffing and -- puffing we might end up with two local names with distinct -- uniques, but the same OccName. Indeed we can, but that's ok -- * the insides of the compiler don't care: they use the Unique -- * when printing for -ddump-xxx you can switch on -dppr-debug to get the -- uniques if you get confused -- * for interface files we tidyCore first, which makes -- the OccNames distinct when they need to be mkClonedInternalName :: Unique -> Name -> Name mkClonedInternalName uniq (Name { n_occ = occ, n_loc = loc }) = Name { n_uniq = getKey uniq, n_sort = Internal , n_occ = occ, n_loc = loc } mkDerivedInternalName :: (OccName -> OccName) -> Unique -> Name -> Name mkDerivedInternalName derive_occ uniq (Name { n_occ = occ, n_loc = loc }) = Name { n_uniq = getKey uniq, n_sort = Internal , n_occ = derive_occ occ, n_loc = loc } -- | Create a name which definitely originates in the given module mkExternalName :: Unique -> Module -> OccName -> SrcSpan -> Name -- WATCH OUT! External Names should be in the Name Cache -- (see Note [The Name Cache] in IfaceEnv), so don't just call mkExternalName -- with some fresh unique without populating the Name Cache mkExternalName uniq mod occ loc = Name { n_uniq = getKey uniq, n_sort = External mod, n_occ = occ, n_loc = loc } -- | Create a name which is actually defined by the compiler itself mkWiredInName :: Module -> OccName -> Unique -> TyThing -> BuiltInSyntax -> Name mkWiredInName mod occ uniq thing built_in = Name { n_uniq = getKey uniq, n_sort = WiredIn mod thing built_in, n_occ = occ, n_loc = wiredInSrcSpan } -- | Create a name brought into being by the compiler mkSystemName :: Unique -> OccName -> Name mkSystemName uniq occ = mkSystemNameAt uniq occ noSrcSpan mkSystemNameAt :: Unique -> OccName -> SrcSpan -> Name mkSystemNameAt uniq occ loc = Name { n_uniq = getKey uniq, n_sort = System , n_occ = occ, n_loc = loc } mkSystemVarName :: Unique -> FastString -> Name mkSystemVarName uniq fs = mkSystemName uniq (mkVarOccFS fs) mkSysTvName :: Unique -> FastString -> Name mkSysTvName uniq fs = mkSystemName uniq (mkOccNameFS tvName fs) -- | Make a name for a foreign call mkFCallName :: Unique -> String -> Name mkFCallName uniq str = mkInternalName uniq (mkVarOcc str) noSrcSpan -- The encoded string completely describes the ccall -- When we renumber/rename things, we need to be -- able to change a Name's Unique to match the cached -- one in the thing it's the name of. If you know what I mean. setNameUnique :: Name -> Unique -> Name setNameUnique name uniq = name {n_uniq = getKey uniq} -- This is used for hsigs: we want to use the name of the originally exported -- entity, but edit the location to refer to the reexport site setNameLoc :: Name -> SrcSpan -> Name setNameLoc name loc = name {n_loc = loc} tidyNameOcc :: Name -> OccName -> Name -- We set the OccName of a Name when tidying -- In doing so, we change System --> Internal, so that when we print -- it we don't get the unique by default. It's tidy now! tidyNameOcc name@(Name { n_sort = System }) occ = name { n_occ = occ, n_sort = Internal} tidyNameOcc name occ = name { n_occ = occ } -- | Make the 'Name' into an internal name, regardless of what it was to begin with localiseName :: Name -> Name localiseName n = n { n_sort = Internal } -- |Create a localised variant of a name. -- -- If the name is external, encode the original's module name to disambiguate. -- SPJ says: this looks like a rather odd-looking function; but it seems to -- be used only during vectorisation, so I'm not going to worry mkLocalisedOccName :: Module -> (Maybe String -> OccName -> OccName) -> Name -> OccName mkLocalisedOccName this_mod mk_occ name = mk_occ origin (nameOccName name) where origin | nameIsLocalOrFrom this_mod name = Nothing | otherwise = Just (moduleNameColons . moduleName . nameModule $ name) {- ************************************************************************ * * \subsection{Hashing and comparison} * * ************************************************************************ -} cmpName :: Name -> Name -> Ordering cmpName n1 n2 = n_uniq n1 `compare` n_uniq n2 -- | Compare Names lexicographically -- This only works for Names that originate in the source code or have been -- tidied. stableNameCmp :: Name -> Name -> Ordering stableNameCmp (Name { n_sort = s1, n_occ = occ1 }) (Name { n_sort = s2, n_occ = occ2 }) = (s1 `sort_cmp` s2) `thenCmp` (occ1 `compare` occ2) -- The ordinary compare on OccNames is lexicographic where -- Later constructors are bigger sort_cmp (External m1) (External m2) = m1 `stableModuleCmp` m2 sort_cmp (External {}) _ = LT sort_cmp (WiredIn {}) (External {}) = GT sort_cmp (WiredIn m1 _ _) (WiredIn m2 _ _) = m1 `stableModuleCmp` m2 sort_cmp (WiredIn {}) _ = LT sort_cmp Internal (External {}) = GT sort_cmp Internal (WiredIn {}) = GT sort_cmp Internal Internal = EQ sort_cmp Internal System = LT sort_cmp System System = EQ sort_cmp System _ = GT {- ************************************************************************ * * \subsection[Name-instances]{Instance declarations} * * ************************************************************************ -} instance Eq Name where a == b = case (a `compare` b) of { EQ -> True; _ -> False } a /= b = case (a `compare` b) of { EQ -> False; _ -> True } instance Ord Name where a <= b = case (a `compare` b) of { LT -> True; EQ -> True; GT -> False } a < b = case (a `compare` b) of { LT -> True; EQ -> False; GT -> False } a >= b = case (a `compare` b) of { LT -> False; EQ -> True; GT -> True } a > b = case (a `compare` b) of { LT -> False; EQ -> False; GT -> True } compare a b = cmpName a b instance Uniquable Name where getUnique = nameUnique instance NamedThing Name where getName n = n instance Data Name where -- don't traverse? toConstr _ = abstractConstr "Name" gunfold _ _ = error "gunfold" dataTypeOf _ = mkNoRepType "Name" {- ************************************************************************ * * \subsection{Binary} * * ************************************************************************ -} -- | Assumes that the 'Name' is a non-binding one. See -- 'IfaceSyn.putIfaceTopBndr' and 'IfaceSyn.getIfaceTopBndr' for serializing -- binding 'Name's. See 'UserData' for the rationale for this distinction. instance Binary Name where put_ bh name = case getUserData bh of UserData{ ud_put_nonbinding_name = put_name } -> put_name bh name get bh = case getUserData bh of UserData { ud_get_name = get_name } -> get_name bh {- ************************************************************************ * * \subsection{Pretty printing} * * ************************************************************************ -} instance Outputable Name where ppr name = pprName name instance OutputableBndr Name where pprBndr _ name = pprName name pprInfixOcc = pprInfixName pprPrefixOcc = pprPrefixName pprName :: Name -> SDoc pprName (Name {n_sort = sort, n_uniq = u, n_occ = occ}) = getPprStyle $ \ sty -> case sort of WiredIn mod _ builtin -> pprExternal sty uniq mod occ True builtin External mod -> pprExternal sty uniq mod occ False UserSyntax System -> pprSystem sty uniq occ Internal -> pprInternal sty uniq occ where uniq = mkUniqueGrimily u pprExternal :: PprStyle -> Unique -> Module -> OccName -> Bool -> BuiltInSyntax -> SDoc pprExternal sty uniq mod occ is_wired is_builtin | codeStyle sty = ppr mod <> char '_' <> ppr_z_occ_name occ -- In code style, always qualify -- ToDo: maybe we could print all wired-in things unqualified -- in code style, to reduce symbol table bloat? | debugStyle sty = pp_mod <> ppr_occ_name occ <> braces (hsep [if is_wired then text "(w)" else empty, pprNameSpaceBrief (occNameSpace occ), pprUnique uniq]) | BuiltInSyntax <- is_builtin = ppr_occ_name occ -- Never qualify builtin syntax | otherwise = if isHoleModule mod then case qualName sty mod occ of NameUnqual -> ppr_occ_name occ _ -> braces (ppr (moduleName mod) <> dot <> ppr_occ_name occ) else pprModulePrefix sty mod occ <> ppr_occ_name occ where pp_mod = sdocWithDynFlags $ \dflags -> if gopt Opt_SuppressModulePrefixes dflags then empty else ppr mod <> dot pprInternal :: PprStyle -> Unique -> OccName -> SDoc pprInternal sty uniq occ | codeStyle sty = pprUniqueAlways uniq | debugStyle sty = ppr_occ_name occ <> braces (hsep [pprNameSpaceBrief (occNameSpace occ), pprUnique uniq]) | dumpStyle sty = ppr_occ_name occ <> ppr_underscore_unique uniq -- For debug dumps, we're not necessarily dumping -- tidied code, so we need to print the uniques. | otherwise = ppr_occ_name occ -- User style -- Like Internal, except that we only omit the unique in Iface style pprSystem :: PprStyle -> Unique -> OccName -> SDoc pprSystem sty uniq occ | codeStyle sty = pprUniqueAlways uniq | debugStyle sty = ppr_occ_name occ <> ppr_underscore_unique uniq <> braces (pprNameSpaceBrief (occNameSpace occ)) | otherwise = ppr_occ_name occ <> ppr_underscore_unique uniq -- If the tidy phase hasn't run, the OccName -- is unlikely to be informative (like 's'), -- so print the unique pprModulePrefix :: PprStyle -> Module -> OccName -> SDoc -- Print the "M." part of a name, based on whether it's in scope or not -- See Note [Printing original names] in HscTypes pprModulePrefix sty mod occ = sdocWithDynFlags $ \dflags -> if gopt Opt_SuppressModulePrefixes dflags then empty else case qualName sty mod occ of -- See Outputable.QualifyName: NameQual modname -> ppr modname <> dot -- Name is in scope NameNotInScope1 -> ppr mod <> dot -- Not in scope NameNotInScope2 -> ppr (moduleUnitId mod) <> colon -- Module not in <> ppr (moduleName mod) <> dot -- scope either NameUnqual -> empty -- In scope unqualified pprUnique :: Unique -> SDoc -- Print a unique unless we are suppressing them pprUnique uniq = sdocWithDynFlags $ \dflags -> ppUnless (gopt Opt_SuppressUniques dflags) $ pprUniqueAlways uniq ppr_underscore_unique :: Unique -> SDoc -- Print an underscore separating the name from its unique -- But suppress it if we aren't printing the uniques anyway ppr_underscore_unique uniq = sdocWithDynFlags $ \dflags -> ppUnless (gopt Opt_SuppressUniques dflags) $ char '_' <> pprUniqueAlways uniq ppr_occ_name :: OccName -> SDoc ppr_occ_name occ = ftext (occNameFS occ) -- Don't use pprOccName; instead, just print the string of the OccName; -- we print the namespace in the debug stuff above -- In code style, we Z-encode the strings. The results of Z-encoding each FastString are -- cached behind the scenes in the FastString implementation. ppr_z_occ_name :: OccName -> SDoc ppr_z_occ_name occ = ztext (zEncodeFS (occNameFS occ)) -- Prints (if mod information is available) "Defined at " or -- "Defined in " information for a Name. pprDefinedAt :: Name -> SDoc pprDefinedAt name = text "Defined" <+> pprNameDefnLoc name pprNameDefnLoc :: Name -> SDoc -- Prints "at " or -- or "in " depending on what info is available pprNameDefnLoc name = case nameSrcLoc name of -- nameSrcLoc rather than nameSrcSpan -- It seems less cluttered to show a location -- rather than a span for the definition point RealSrcLoc s -> text "at" <+> ppr s UnhelpfulLoc s | isInternalName name || isSystemName name -> text "at" <+> ftext s | otherwise -> text "in" <+> quotes (ppr (nameModule name)) -- | Get a string representation of a 'Name' that's unique and stable -- across recompilations. Used for deterministic generation of binds for -- derived instances. -- eg. "$aeson_70dylHtv1FFGeai1IoxcQr$Data.Aeson.Types.Internal$String" nameStableString :: Name -> String nameStableString Name{..} = nameSortStableString n_sort ++ "$" ++ occNameString n_occ nameSortStableString :: NameSort -> String nameSortStableString System = "$_sys" nameSortStableString Internal = "$_in" nameSortStableString (External mod) = moduleStableString mod nameSortStableString (WiredIn mod _ _) = moduleStableString mod {- ************************************************************************ * * \subsection{Overloaded functions related to Names} * * ************************************************************************ -} -- | A class allowing convenient access to the 'Name' of various datatypes class NamedThing a where getOccName :: a -> OccName getName :: a -> Name getOccName n = nameOccName (getName n) -- Default method instance NamedThing e => NamedThing (GenLocated l e) where getName = getName . unLoc getSrcLoc :: NamedThing a => a -> SrcLoc getSrcSpan :: NamedThing a => a -> SrcSpan getOccString :: NamedThing a => a -> String getOccFS :: NamedThing a => a -> FastString getSrcLoc = nameSrcLoc . getName getSrcSpan = nameSrcSpan . getName getOccString = occNameString . getOccName getOccFS = occNameFS . getOccName pprInfixName :: (Outputable a, NamedThing a) => a -> SDoc -- See Outputable.pprPrefixVar, pprInfixVar; -- add parens or back-quotes as appropriate pprInfixName n = pprInfixVar (isSymOcc (getOccName n)) (ppr n) pprPrefixName :: NamedThing a => a -> SDoc pprPrefixName thing | name `hasKey` starKindTyConKey || name `hasKey` unicodeStarKindTyConKey = ppr name -- See Note [Special treatment for kind *] | otherwise = pprPrefixVar (isSymOcc (nameOccName name)) (ppr name) where name = getName thing {- Note [Special treatment for kind *] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Do not put parens around the kind '*'. Even though it looks like an operator, it is really a special case. This pprPrefixName stuff is really only used when printing HsSyn, which has to be polymorphic in the name type, and hence has to go via the overloaded function pprPrefixOcc. It's easier where we know the type being pretty printed; eg the pretty-printing code in TyCoRep. See Trac #7645, which led to this. -}