-- The environment types
Env(..),
TcGblEnv(..), TcLclEnv(..),
- IfGblEnv(..), IfLclEnv(..),
+ IfGblEnv(..), IfLclEnv(..),
-- Ranamer types
ErrCtxt,
WhereFrom(..), mkModDeps,
-- Typechecker types
- TcTyThing(..), GadtRefinement,
+ TcTyThing(..), pprTcTyThingCategory, GadtRefinement,
-- Template Haskell
ThStage(..), topStage, topSpliceStage,
ThLevel, impLevel, topLevel,
-- Arrows
- ArrowCtxt(..), topArrowCtxt, ProcLevel, topProcLevel,
+ ArrowCtxt(NoArrowCtxt), newArrowScope, escapeArrowScope,
-- Insts
Inst(..), InstOrigin(..), InstLoc(..), pprInstLoc,
#include "HsVersions.h"
import HsSyn ( PendingSplice, HsOverLit, LRuleDecl, LForeignDecl,
- ArithSeqInfo, DictBinds, LHsBinds )
+ ArithSeqInfo, DictBinds, LHsBinds, HsGroup )
import HscTypes ( FixityEnv,
HscEnv, TypeEnv, TyThing,
- GenAvailInfo(..), AvailInfo,
+ GenAvailInfo(..), AvailInfo, HscSource(..),
availName, IsBootInterface, Deprecations )
-import Packages ( PackageId )
-import Type ( Type, TvSubstEnv, pprParendType )
+import Packages ( PackageId, HomeModules )
+import Type ( Type, TvSubstEnv, pprParendType, pprTyThingCategory )
import TcType ( TcTyVarSet, TcType, TcTauType, TcThetaType, SkolemInfo,
- TcPredType, TcKind, tcCmpPred, tcCmpType, tcCmpTypes )
-import InstEnv ( DFunId, InstEnv )
+ TcPredType, TcKind, tcCmpPred, tcCmpType, tcCmpTypes, pprSkolInfo )
+import InstEnv ( Instance, InstEnv )
import IOEnv
import RdrName ( GlobalRdrEnv, LocalRdrEnv )
import Name ( Name )
data TcGblEnv
= TcGblEnv {
tcg_mod :: Module, -- Module being compiled
+ tcg_src :: HscSource, -- What kind of module
+ -- (regular Haskell, hs-boot, ext-core)
+
tcg_rdr_env :: GlobalRdrEnv, -- Top level envt; used during renaming
tcg_default :: Maybe [Type], -- Types used for defaulting
-- Nothing => no 'default' decl
-- from where, including things bound
-- in this module
+ tcg_home_mods :: HomeModules,
+ -- Calculated from ImportAvails, allows us to
+ -- call Packages.isHomeModule
+
tcg_dus :: DefUses, -- What is defined in this module and what is used.
-- The latter is used to generate
-- (a) version tracking; no need to recompile if these
-- tcg_inst_uses; the reference is implicit rather than explicit,
-- so we have to zap a mutable variable.
+ tcg_dfun_n :: TcRef Int, -- Allows us to number off the names of DFuns
+ -- It's convenient to allocate an External Name for a DFun, with
+ -- a permanently-fixed unique, just like other top-level functions
+ -- defined in this module. But that means we need a canonical
+ -- occurrence name, distinct from all other dfuns in this module,
+ -- and this name supply serves that purpose (df1, df2, etc).
+
-- 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
+
+ -- 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_rn_decls :: Maybe (HsGroup Name), -- renamed decls, maybe
+ -- Nothing <=> Don't retain renamed decls
+
tcg_binds :: LHsBinds Id, -- Value bindings in this module
tcg_deprecs :: Deprecations, -- ...Deprecations
- tcg_insts :: [DFunId], -- ...Instances
+ tcg_insts :: [Instance], -- ...Instances
tcg_rules :: [LRuleDecl Id], -- ...Rules
tcg_fords :: [LForeignDecl Id] -- ...Foreign import & exports
}
-- it means M.f = \x -> x, where M is the if_mod
if_mod :: Module,
+ -- The field is used only for error reporting
+ -- if (say) there's a Lint error in it
+ if_loc :: SDoc,
+ -- Where the interface came from:
+ -- .hi file, or GHCi state, or ext core
+ -- plus which bit is currently being examined
+
if_tv_env :: OccEnv TyVar, -- Nested tyvar bindings
if_id_env :: OccEnv Id -- Nested id binding
}
topStage = Comp
topSpliceStage = Splice (topLevel - 1) -- Stage for the body of a top-level splice
-
---------------------------
--- Arrow-notation stages
+-- Arrow-notation context
---------------------------
--- In arrow notation, a variable bound by a proc (or enclosed let/kappa)
--- is not in scope to the left of an arrow tail (-<). For example
---
--- proc x -> (e1 -< e2)
---
--- Here, x is not in scope in e1, but it is in scope in e2. This can get
--- a bit complicated:
---
--- let x = 3 in
--- prox y -> (proc z -> e1) -< e2
---
--- Here, x and z are in scope in e1, but y is not. Here's how we track this:
--- a) Assign an "proc level" to each proc, being the number of
--- lexically-enclosing procs + 1.
--- b) Assign to each local variable the proc-level of its lexically
--- enclosing proc.
--- c) Keep a list of out-of-scope procs. When moving to the left of
--- an arrow-tail, add the proc-level of the immediately enclosing
--- proc to the list.
--- d) When looking up a variable, complain if its proc-level is in
--- the banned list
+{-
+In arrow notation, a variable bound by a proc (or enclosed let/kappa)
+is not in scope to the left of an arrow tail (-<) or the head of (|..|).
+For example
+
+ proc x -> (e1 -< e2)
-type ProcLevel = Int -- Always >= 0
-topProcLevel = 0 -- Not inside any proc
+Here, x is not in scope in e1, but it is in scope in e2. This can get
+a bit complicated:
-data ArrowCtxt = ArrCtxt { proc_level :: ProcLevel, -- Current level
- proc_banned :: [ProcLevel] } -- Out of scope proc-levels
+ let x = 3 in
+ proc y -> (proc z -> e1) -< e2
+
+Here, x and z are in scope in e1, but y is not. We implement this by
+recording the environment when passing a proc (using newArrowScope),
+and returning to that (using escapeArrowScope) on the left of -< and the
+head of (|..|).
+-}
-topArrowCtxt = ArrCtxt { proc_level = topProcLevel, proc_banned = [] }
+data ArrowCtxt
+ = NoArrowCtxt
+ | ArrowCtxt (Env TcGblEnv TcLclEnv)
+
+-- Record the current environment (outside a proc)
+newArrowScope :: TcM a -> TcM a
+newArrowScope
+ = updEnv $ \env ->
+ env { env_lcl = (env_lcl env) { tcl_arrow_ctxt = ArrowCtxt env } }
+
+-- Return to the stored environment (from the enclosing proc)
+escapeArrowScope :: TcM a -> TcM a
+escapeArrowScope
+ = updEnv $ \ env -> case tcl_arrow_ctxt (env_lcl env) of
+ NoArrowCtxt -> env
+ ArrowCtxt env' -> env'
---------------------------
-- TcTyThing
data TcTyThing
= 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
+ | ATcId TcId ThLevel -- Ids defined in this module; may not be fully zonked
- | ATyVar TyVar TcType -- Type variables; tv -> type. It can't just be a TyVar
+ | ATyVar Name TcType -- Type variables; tv -> type. It can't just be a TyVar
-- that is mutated to point to the type it is bound to,
-- because that would make it a wobbly type, and we
-- want pattern-bound lexically-scoped type variables to
-- 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 tv ty) = text "ATyVar" <+> ppr tv <+> pprParendType ty
+ ppr (AGlobal g) = ppr g
+ ppr (ATcId g tl) = text "Identifier" <>
+ ifPprDebug (brackets (ppr g <> comma <> ppr tl))
+ ppr (ATyVar tv ty) = text "Type variable" <+> quotes (ppr tv) <+> pprParendType ty
ppr (AThing k) = text "AThing" <+> ppr k
+
+pprTcTyThingCategory :: TcTyThing -> SDoc
+pprTcTyThingCategory (AGlobal thing) = pprTyThingCategory thing
+pprTcTyThingCategory (ATyVar _ _) = ptext SLIT("Type variable")
+pprTcTyThingCategory (ATcId _ _) = ptext SLIT("Local identifier")
+pprTcTyThingCategory (AThing _) = ptext SLIT("Kinded thing")
\end{code}
\begin{code}
-- So the starting point is all things that are in scope as 'M.x',
-- which is what this field tells us.
- imp_mods :: ModuleEnv (Module, Maybe Bool, SrcSpan),
+ imp_mods :: ModuleEnv (Module, Bool, SrcSpan),
-- Domain is all directly-imported modules
- -- Maybe value answers the question "is the import restricted?"
- -- Nothing => unrestricted import (e.g., "import Foo")
- -- Just True => restricted import, at least one entity (e.g., "import Foo(x)")
- -- Just False => fully restricted import (e.g., "import Foo ()")
- --
- -- A distinction is made between the first and the third in order
- -- to more precisely emit warnings about unused imports.
+ -- Bool means:
+ -- True => import was "import Foo ()"
+ -- False => import was some other form
--
-- We need the Module in the range because we can't get
-- the keys of a ModuleEnv
-- Used
-- (a) to help construct the usage information in
- -- the interface file; if we import everything we
- -- need to recompile if the module version changes
+ -- the interface file; if we import somethign we
+ -- need to recompile if the export version changes
-- (b) to specify what child modules to initialise
imp_dep_mods :: ModuleEnv (Module, IsBootInterface),
| LitInst
Name
- HsOverLit -- The literal from the occurrence site
- -- INVARIANT: never a rebindable-syntax literal
- -- Reason: tcSyntaxName does unification, and we
- -- don't want to deal with that during tcSimplify
+ (HsOverLit Name) -- The literal from the occurrence site
+ -- INVARIANT: never a rebindable-syntax literal
+ -- Reason: tcSyntaxName does unification, and we
+ -- don't want to deal with that during tcSimplify,
+ -- when resolving LitInsts
TcType -- The type at which the literal is used
InstLoc
\end{code}
| IPOccOrigin (IPName Name) -- Occurrence of an implicit parameter
- | LiteralOrigin HsOverLit -- Occurrence of a literal
+ | LiteralOrigin (HsOverLit Name) -- Occurrence of a literal
| ArithSeqOrigin (ArithSeqInfo Name) -- [x..], [x..y] etc
| PArrSeqOrigin (ArithSeqInfo Name) -- [:x..y:] and [:x,y..z:]
\begin{code}
pprInstLoc :: InstLoc -> SDoc
-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 (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 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
+ pp_orig DoOrigin = ptext SLIT("a do statement")
+ pp_orig ProcOrigin = ptext SLIT("a proc expression")
+ pp_orig (SigOrigin info) = pprSkolInfo info
\end{code}
projects / ghc-hetmet.git / blobdiff