WhereFrom(..), mkModDeps,
-- Typechecker types
- TcTyThing(..),
+ TcTyThing(..), GadtRefinement,
-- Template Haskell
ThStage(..), topStage, topSpliceStage,
ArrowCtxt(..), topArrowCtxt, ProcLevel, topProcLevel,
-- Insts
- Inst(..), InstOrigin(..), InstLoc(..), pprInstLoc, instLocSrcLoc,
+ Inst(..), InstOrigin(..), InstLoc(..), pprInstLoc,
+ instLocSrcLoc, instLocSrcSpan,
LIE, emptyLIE, unitLIE, plusLIE, consLIE,
plusLIEs, mkLIE, isEmptyLIE, lieToList, listToLIE,
-- Misc other types
- TcId, TcIdSet
+ TcId, TcIdSet, TcDictBinds
) where
#include "HsVersions.h"
-import HsSyn ( PendingSplice, HsOverLit, MonoBinds, RuleDecl, ForeignDecl )
-import RnHsSyn ( RenamedPat, RenamedArithSeqInfo )
+import HsSyn ( PendingSplice, HsOverLit, LRuleDecl, LForeignDecl,
+ ArithSeqInfo, DictBinds, LHsBinds )
import HscTypes ( FixityEnv,
HscEnv, TypeEnv, TyThing,
- Avails, GenAvailInfo(..), AvailInfo,
+ GenAvailInfo(..), AvailInfo,
availName, IsBootInterface, Deprecations )
import Packages ( PackageName )
-import TcType ( TcTyVarSet, TcType, TcTauType, TcThetaType,
+import Type ( Type, TvSubstEnv )
+import TcType ( TcTyVarSet, TcType, TcTauType, TcThetaType, SkolemInfo,
TcPredType, TcKind, tcCmpPred, tcCmpType, tcCmpTypes )
import InstEnv ( DFunId, InstEnv )
import IOEnv
import NameEnv
import NameSet ( NameSet, emptyNameSet, DefUses )
import OccName ( OccEnv )
-import Type ( Type )
-import Class ( Class )
import Var ( Id, TyVar )
import VarEnv ( TidyEnv )
import Module
-import SrcLoc ( SrcLoc )
+import SrcLoc ( SrcSpan, SrcLoc, srcSpanStart )
import VarSet ( IdSet )
import ErrUtils ( Messages, Message )
import UniqSupply ( UniqSupply )
The monad itself has to be defined here, because it is mentioned by ErrCtxt
\begin{code}
-type TcRef a = IORef a
-type TcId = Id -- Type may be a TcType
-type TcIdSet = IdSet
+type TcRef a = IORef a
+type TcId = Id -- Type may be a TcType
+type TcIdSet = IdSet
+type TcDictBinds = DictBinds TcId -- Bag of dictionary bindings
+
+
type TcRnIf a b c = IOEnv (Env a b) c
type IfM lcl a = TcRnIf IfGblEnv lcl a -- Iface stuff
data Env gbl lcl -- Changes as we move into an expression
= Env {
env_top :: HscEnv, -- Top-level stuff that never changes
- -- Includes all info about imported things
+ -- Includes all info about imported things
env_us :: TcRef UniqSupply, -- Unique supply for local varibles
env_gbl :: gbl, -- Info about things defined at the top level
- -- of the module being compiled
+ -- of the module being compiled
- env_lcl :: lcl -- Nested stuff -- changes as we go into
+ env_lcl :: lcl -- Nested stuff; changes as we go into
-- an expression
}
tcg_inst_env :: InstEnv, -- Instance envt for *home-package* modules
-- Includes the dfuns in tcg_insts
- tcg_inst_uses :: TcRef NameSet, -- Home-package Dfuns actually used
- -- Used to generate version dependencies
- -- This records usages, rather like tcg_dus, but it has to
- -- be a mutable variable so it can be augmented
- -- when we look up an instance. These uses of dfuns are
- -- rather like the free variables of the program, but
- -- are implicit instead of explicit.
-
-- Now a bunch of things about this module that are simply
-- accumulated, but never consulted until the end.
-- Nevertheless, it's convenient to accumulate them along
-- with the rest of the info from this module.
- tcg_exports :: Avails, -- What is exported
- tcg_imports :: ImportAvails, -- Information about what was imported
- -- from where, including things bound
- -- in this module
+ tcg_exports :: NameSet, -- What is exported
+ tcg_imports :: ImportAvails, -- Information about what was imported
+ -- from where, including things bound
+ -- in this module
tcg_dus :: DefUses, -- What is defined in this module and what is used.
-- The latter is used to generate
-- things have not changed version stamp
-- (b) unused-import info
- tcg_keep :: NameSet, -- Set of names to keep alive, and to expose in the
- -- interface file (but not to export to the user).
- -- These are typically extra definitions generated from
- -- data type declarations which would otherwise be
- -- dropped as dead code.
+ tcg_keep :: TcRef NameSet, -- Locally-defined top-level names to keep alive
+ -- "Keep alive" means give them an Exported flag, so
+ -- that the simplifier does not discard them as dead
+ -- code, and so that they are exposed in the interface file
+ -- (but not to export to the user).
+ --
+ -- Some things, like dict-fun Ids and default-method Ids are
+ -- "born" with the Exported flag on, for exactly the above reason,
+ -- but some we only discover as we go. Specifically:
+ -- * The to/from functions for generic data types
+ -- * Top-level variables appearing free in the RHS of an orphan rule
+ -- * Top-level variables appearing free in a TH bracket
+
+ tcg_inst_uses :: TcRef NameSet, -- Home-package Dfuns actually used
+ -- Used to generate version dependencies
+ -- This records usages, rather like tcg_dus, but it has to
+ -- be a mutable variable so it can be augmented
+ -- when we look up an instance. These uses of dfuns are
+ -- rather like the free variables of the program, but
+ -- are implicit instead of explicit.
+
+ tcg_th_used :: TcRef Bool, -- True <=> Template Haskell syntax used
+ -- We need this so that we can generate a dependency on the
+ -- Template Haskell package, becuase the desugarer is going to
+ -- emit loads of references to TH symbols. It's rather like
+ -- tcg_inst_uses; the reference is implicit rather than explicit,
+ -- so we have to zap a mutable variable.
-- The next fields accumulate the payload of the module
-- The binds, rules and foreign-decl fiels are collected
-- initially in un-zonked form and are finally zonked in tcRnSrcDecls
- tcg_binds :: MonoBinds Id, -- Value bindings in this module
+ tcg_binds :: LHsBinds Id, -- Value bindings in this module
tcg_deprecs :: Deprecations, -- ...Deprecations
tcg_insts :: [DFunId], -- ...Instances
- tcg_rules :: [RuleDecl Id], -- ...Rules
- tcg_fords :: [ForeignDecl Id] -- ...Foreign import & exports
+ tcg_rules :: [LRuleDecl Id], -- ...Rules
+ tcg_fords :: [LForeignDecl Id] -- ...Foreign import & exports
}
\end{code}
-- was originally a hi-boot file.
-- We need the module name so we can test when it's appropriate
-- to look in this env.
- if_rec_types :: Maybe (Module, IfG TypeEnv),
+ if_rec_types :: Maybe (Module, IfG TypeEnv)
-- Allows a read effect, so it can be in a mutable
-- variable; c.f. handling the external package type env
-- Nothing => interactive stuff, no loops possible
-
- if_is_boot :: ModuleEnv (ModuleName, IsBootInterface)
- -- Tells what we know about boot interface files
- -- When we're importing a module we know absolutely
- -- nothing about, so we assume it's from
- -- another package, where we aren't doing
- -- dependency tracking. So it won't be a hi-boot file.
}
data IfLclEnv
data TcLclEnv -- Changes as we move inside an expression
-- Discarded after typecheck/rename; not passed on to desugarer
= TcLclEnv {
- tcl_loc :: SrcLoc, -- Source location
+ tcl_loc :: SrcSpan, -- Source span
tcl_ctxt :: ErrCtxt, -- Error context
tcl_errs :: TcRef Messages, -- Place to accumulate errors
tcl_arrow_ctxt :: ArrowCtxt, -- Arrow-notation context
tcl_rdr :: LocalRdrEnv, -- Local name envt
+ -- Maintained during renaming, of course, but also during
+ -- type checking, solely so that when renaming a Template-Haskell
+ -- splice we have the right environment for the renamer.
+ --
-- Does *not* include global name envt; may shadow it
-- Includes both ordinary variables and type variables;
-- they are kept distinct because tyvar have a different
-- We still need the unsullied global name env so that
-- we can look up record field names
- tcl_env :: NameEnv TcTyThing, -- The local type environment: Ids and TyVars
- -- defined in this module
+ tcl_env :: NameEnv TcTyThing, -- The local type environment: Ids and TyVars
+ -- defined in this module
tcl_tyvars :: TcRef TcTyVarSet, -- The "global tyvars"
- -- Namely, the in-scope TyVars bound in tcl_lenv,
+ -- Namely, the in-scope TyVars bound in tcl_env,
-- plus the tyvars mentioned in the types of Ids bound in tcl_lenv
-- Why mutable? see notes with tcGetGlobalTyVars
- tcl_lie :: TcRef LIE -- Place to accumulate type constraints
+ tcl_lie :: TcRef LIE, -- Place to accumulate type constraints
+ tcl_gadt :: GadtRefinement -- The current type refinement for GADTs
+
+-----------------------------------------------------------
+-- Not yet; it's a new complication and I want to see whether it bites
+-- tcl_given :: [Inst] -- Insts available in the current context (see Note [Given Insts])
+-----------------------------------------------------------
}
+type GadtRefinement = TvSubstEnv -- Binds rigid type variables to their refinements
+
+{- Note [Given Insts]
+ ~~~~~~~~~~~~~~~~~~
+Because of GADTs, we have to pass inwards the Insts provided by type signatures
+and existential contexts. Consider
+ data T a where { T1 :: b -> b -> T [b] }
+ f :: Eq a => T a -> Bool
+ f (T1 x y) = [x]==[y]
+
+The constructor T1 binds an existential variable 'b', and we need Eq [b].
+Well, we have it, because Eq a refines to Eq [b], but we can only spot that if we
+pass it inwards.
+
+-}
+
---------------------------
-- Template Haskell levels
---------------------------
-type ThLevel = Int -- Always >= 0
+type ThLevel = Int
+ -- Indicates how many levels of brackets we are inside
+ -- (always >= 0)
+ -- Incremented when going inside a bracket,
+ -- decremented when going inside a splice
+
+impLevel, topLevel :: ThLevel
+topLevel = 1 -- Things defined at top level of this module
+impLevel = 0 -- Imported things; they can be used inside a top level splice
+--
+-- For example:
+-- f = ...
+-- g1 = $(map ...) is OK
+-- g2 = $(f ...) is not OK; because we havn't compiled f yet
+
data ThStage
= Comp -- Ordinary compiling, at level topLevel
topSpliceStage = Splice (topLevel - 1) -- Stage for the body of a top-level splice
-impLevel, topLevel :: ThLevel
-topLevel = 1 -- Things defined at top level of this module
-impLevel = 0 -- Imported things; they can be used inside a top level splice
---
--- For example:
--- f = ...
--- g1 = $(map ...) is OK
--- g2 = $(f ...) is not OK; because we havn't compiled f yet
-
-
---------------------------
-- Arrow-notation stages
---------------------------
= AGlobal TyThing -- Used only in the return type of a lookup
| ATcId TcId ThLevel ProcLevel -- Ids defined in this module; may not be fully zonked
| ATyVar TyVar -- Type variables
- | ARecTyCon TcKind -- Used temporarily, during kind checking, for the
- | ARecClass TcKind -- tycons and clases in this recursive group
+ | AThing TcKind -- Used temporarily, during kind checking, for the
+ -- tycons and clases in this recursive group
instance Outputable TcTyThing where -- Debugging only
ppr (AGlobal g) = text "AGlobal" <+> ppr g
ppr (ATcId g tl pl) = text "ATcId" <+> ppr g <+> ppr tl <+> ppr pl
ppr (ATyVar t) = text "ATyVar" <+> ppr t
- ppr (ARecTyCon k) = text "ARecTyCon" <+> ppr k
- ppr (ARecClass k) = text "ARecClass" <+> ppr k
+ ppr (AThing k) = text "AThing" <+> ppr k
\end{code}
\begin{code}
-- combine stuff coming from different (unqualified)
-- imports of the same module
- imp_mods :: ModuleEnv (Module, Maybe Bool),
+ imp_mods :: ModuleEnv (Module, Maybe Bool, SrcSpan),
-- Domain is all directly-imported modules
-- Maybe value answers the question "is the import restricted?"
-- Nothing => unrestricted import (e.g., "import Foo")
\begin{code}
data Inst
= Dict
- Id
+ Name
TcPredType
InstLoc
-- type of (f tys dicts(from theta)) = tau
-- INVARIANT 2: tau must not be of form (Pred -> Tau)
- -- Reason: two methods are considerd equal if the
+ -- Reason: two methods are considered equal if the
-- base Id matches, and the instantiating types
-- match. The TcThetaType should then match too.
-- This only bites in the call to tcInstClassOp in TcClassDcl.mkMethodBind
| LitInst
- Id
+ Name
HsOverLit -- The literal from the occurrence site
-- INVARIANT: never a rebindable-syntax literal
-- Reason: tcSyntaxName does unification, and we
functions that deal with it.
\begin{code}
-data InstLoc = InstLoc InstOrigin SrcLoc ErrCtxt
+data InstLoc = InstLoc InstOrigin SrcSpan ErrCtxt
instLocSrcLoc :: InstLoc -> SrcLoc
-instLocSrcLoc (InstLoc _ src_loc _) = src_loc
+instLocSrcLoc (InstLoc _ src_span _) = srcSpanStart src_span
-data InstOrigin
- = OccurrenceOf Name -- Occurrence of an overloaded identifier
+instLocSrcSpan :: InstLoc -> SrcSpan
+instLocSrcSpan (InstLoc _ src_span _) = src_span
- | IPOcc (IPName Name) -- Occurrence of an implicit parameter
- | IPBind (IPName Name) -- Binding site of an implicit parameter
+data InstOrigin
+ = SigOrigin SkolemInfo -- Pattern, class decl, inst decl etc;
+ -- Places that bind type variables and introduce
+ -- available constraints
- | RecordUpdOrigin
+ | IPBindOrigin (IPName Name) -- Binding site of an implicit parameter
- | DataDeclOrigin -- Typechecking a data declaration
+ -------------------------------------------------------
+ -- The rest are all occurrences: Insts that are 'wanted'
+ -------------------------------------------------------
+ | OccurrenceOf Name -- Occurrence of an overloaded identifier
- | InstanceDeclOrigin -- Typechecking an instance decl
+ | IPOccOrigin (IPName Name) -- Occurrence of an implicit parameter
| LiteralOrigin HsOverLit -- Occurrence of a literal
- | PatOrigin RenamedPat
-
- | ArithSeqOrigin RenamedArithSeqInfo -- [x..], [x..y] etc
- | PArrSeqOrigin RenamedArithSeqInfo -- [:x..y:] and [:x,y..z:]
+ | ArithSeqOrigin (ArithSeqInfo Name) -- [x..], [x..y] etc
+ | PArrSeqOrigin (ArithSeqInfo Name) -- [:x..y:] and [:x,y..z:]
- | SignatureOrigin -- A dict created from a type signature
- | Rank2Origin -- A dict created when typechecking the argument
- -- of a rank-2 typed function
+ | InstSigOrigin -- A dict occurrence arising from instantiating
+ -- a polymorphic type during a subsumption check
- | DoOrigin -- The monad for a do expression
- | ProcOrigin -- A proc expression
-
- | ClassDeclOrigin -- Manufactured during a class decl
-
- | InstanceSpecOrigin Class -- in a SPECIALIZE instance pragma
- Type
-
- -- When specialising instances the instance info attached to
- -- each class is not yet ready, so we record it inside the
- -- origin information. This is a bit of a hack, but it works
- -- fine. (Patrick is to blame [WDP].)
-
- | ValSpecOrigin Name -- in a SPECIALIZE pragma for a value
-
- -- Argument or result of a ccall
- -- Dictionaries with this origin aren't actually mentioned in the
- -- translated term, and so need not be bound. Nor should they
- -- be abstracted over.
-
- | UnknownOrigin -- Help! I give up...
+ | RecordUpdOrigin
+ | InstScOrigin -- Typechecking superclasses of an instance declaration
+ | DerivOrigin -- Typechecking deriving
+ | DefaultOrigin -- Typechecking a default decl
+ | DoOrigin -- Arising from a do expression
+ | ProcOrigin -- Arising from a proc expression
\end{code}
\begin{code}
pprInstLoc :: InstLoc -> SDoc
-pprInstLoc (InstLoc orig locn ctxt)
+pprInstLoc (InstLoc (SigOrigin info) locn _)
+ = text "arising from" <+> ppr info -- I don't think this happens much, if at all
+pprInstLoc (InstLoc orig locn _)
= hsep [text "arising from", pp_orig orig, text "at", ppr locn]
where
- pp_orig (OccurrenceOf name)
- = hsep [ptext SLIT("use of"), quotes (ppr name)]
- pp_orig (IPOcc name)
- = hsep [ptext SLIT("use of implicit parameter"), quotes (ppr name)]
- pp_orig (IPBind name)
- = hsep [ptext SLIT("binding for implicit parameter"), quotes (ppr name)]
- pp_orig RecordUpdOrigin
- = ptext SLIT("a record update")
- pp_orig DataDeclOrigin
- = ptext SLIT("the data type declaration")
- pp_orig InstanceDeclOrigin
- = ptext SLIT("the instance declaration")
- pp_orig (LiteralOrigin lit)
- = hsep [ptext SLIT("the literal"), quotes (ppr lit)]
- pp_orig (PatOrigin pat)
- = hsep [ptext SLIT("the pattern"), quotes (ppr pat)]
- pp_orig (ArithSeqOrigin seq)
- = hsep [ptext SLIT("the arithmetic sequence"), quotes (ppr seq)]
- pp_orig (PArrSeqOrigin seq)
- = hsep [ptext SLIT("the parallel array sequence"), quotes (ppr seq)]
- pp_orig (SignatureOrigin)
- = ptext SLIT("a type signature")
- pp_orig (Rank2Origin)
- = ptext SLIT("a function with an overloaded argument type")
- pp_orig (DoOrigin)
- = ptext SLIT("a do statement")
- pp_orig (ProcOrigin)
- = ptext SLIT("a proc expression")
- pp_orig (ClassDeclOrigin)
- = ptext SLIT("a class declaration")
- pp_orig (InstanceSpecOrigin clas ty)
- = hsep [text "a SPECIALIZE instance pragma; class",
- quotes (ppr clas), text "type:", ppr ty]
- pp_orig (ValSpecOrigin name)
- = hsep [ptext SLIT("a SPECIALIZE user-pragma for"), quotes (ppr name)]
- pp_orig (UnknownOrigin)
- = ptext SLIT("...oops -- I don't know where the overloading came from!")
+ pp_orig (OccurrenceOf name) = hsep [ptext SLIT("use of"), quotes (ppr name)]
+ pp_orig (IPOccOrigin name) = hsep [ptext SLIT("use of implicit parameter"), quotes (ppr name)]
+ pp_orig (IPBindOrigin name) = hsep [ptext SLIT("binding for implicit parameter"), quotes (ppr name)]
+ pp_orig RecordUpdOrigin = ptext SLIT("a record update")
+ pp_orig (LiteralOrigin lit) = hsep [ptext SLIT("the literal"), quotes (ppr lit)]
+ pp_orig (ArithSeqOrigin seq) = hsep [ptext SLIT("the arithmetic sequence"), quotes (ppr seq)]
+ pp_orig (PArrSeqOrigin seq) = hsep [ptext SLIT("the parallel array sequence"), quotes (ppr seq)]
+ pp_orig InstSigOrigin = ptext SLIT("instantiating a type signature")
+ pp_orig InstScOrigin = ptext SLIT("the superclasses of an instance declaration")
+ pp_orig DerivOrigin = ptext SLIT("the 'deriving' clause of a data type declaration")
+ pp_orig DefaultOrigin = ptext SLIT("a 'default' declaration")
+ pp_orig DoOrigin = ptext SLIT("a do statement")
+ pp_orig ProcOrigin = ptext SLIT("a proc expression")
+ pp_orig (SigOrigin info) = ppr info
\end{code}
projects / ghc-hetmet.git / blobdiff