-- The environment types
Env(..),
TcGblEnv(..), TcLclEnv(..),
- IfGblEnv(..), IfLclEnv(..),
+ IfGblEnv(..), IfLclEnv(..),
-- Ranamer types
- EntityUsage, emptyUsages, ErrCtxt,
+ ErrCtxt,
ImportAvails(..), emptyImportAvails, plusImportAvails,
plusAvail, pruneAvails,
AvailEnv, emptyAvailEnv, unitAvailEnv, plusAvailEnv,
WhereFrom(..), mkModDeps,
-- Typechecker types
- TcTyThing(..),
+ 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,
plusLIEs, mkLIE, isEmptyLIE, lieToList, listToLIE,
-- Misc other types
- TcId, TcIdSet
+ TcId, TcIdSet, TcDictBinds
) where
#include "HsVersions.h"
-import HsSyn ( PendingSplice, HsOverLit, LHsBind, LRuleDecl, LForeignDecl,
- Pat, ArithSeqInfo )
+import HsSyn ( PendingSplice, HsOverLit, LRuleDecl, LForeignDecl,
+ ArithSeqInfo, DictBinds, LHsBinds, LImportDecl, HsGroup,
+ IE )
import HscTypes ( FixityEnv,
HscEnv, TypeEnv, TyThing,
- Avails, GenAvailInfo(..), AvailInfo,
+ GenAvailInfo(..), AvailInfo, HscSource(..),
availName, IsBootInterface, Deprecations )
-import Packages ( PackageName )
-import TcType ( TcTyVarSet, TcType, TcTauType, TcThetaType,
- TcPredType, TcKind, tcCmpPred, tcCmpType, tcCmpTypes )
-import InstEnv ( DFunId, InstEnv )
+import Packages ( PackageId, HomeModules )
+import Type ( Type, pprTyThingCategory )
+import TcType ( TcTyVarSet, TcType, TcThetaType, SkolemInfo, TvSubst,
+ TcPredType, TcKind, tcCmpPred, tcCmpType, tcCmpTypes, pprSkolInfo )
+import InstEnv ( Instance, InstEnv )
import IOEnv
import RdrName ( GlobalRdrEnv, LocalRdrEnv )
import Name ( Name )
import NameEnv
-import NameSet ( NameSet, emptyNameSet, DefUses )
+import NameSet ( NameSet, unionNameSets, DefUses )
import OccName ( OccEnv )
-import Type ( Type )
-import Class ( Class )
import Var ( Id, TyVar )
import VarEnv ( TidyEnv )
import Module
-import SrcLoc ( SrcSpan, SrcLoc, srcSpanStart )
+import SrcLoc ( SrcSpan, SrcLoc, Located, 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
}
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
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_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
-- 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.
+
+ 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
- tcg_binds :: Bag (LHsBind Id), -- Value bindings in this module
+
+ -- 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_imports :: Maybe [LImportDecl Name],
+ tcg_rn_exports :: Maybe [Located (IE Name)],
+ 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
}
-- 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
-- The module for the current IfaceDecl
-- So if we see f = \x -> x
-- it means M.f = \x -> x, where M is the if_mod
- if_mod :: ModuleName,
+ 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
-- 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
}
+type GadtRefinement = TvSubst
+
+{- 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
topStage = Comp
topSpliceStage = Splice (topLevel - 1) -- Stage for the body of a top-level splice
+---------------------------
+-- Arrow-notation context
+---------------------------
-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
+{-
+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)
----------------------------
--- Arrow-notation stages
----------------------------
+Here, x is not in scope in e1, but it is in scope in e2. This can get
+a bit complicated:
--- 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
+ 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 (|..|).
+-}
-type ProcLevel = Int -- Always >= 0
-topProcLevel = 0 -- Not inside any proc
+data ArrowCtxt
+ = NoArrowCtxt
+ | ArrowCtxt (Env TcGblEnv TcLclEnv)
-data ArrowCtxt = ArrCtxt { proc_level :: ProcLevel, -- Current level
- proc_banned :: [ProcLevel] } -- Out of scope proc-levels
+-- 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 } }
-topArrowCtxt = ArrCtxt { proc_level = topProcLevel, proc_banned = [] }
+-- 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
- | ATyVar TyVar -- Type variables
- | ARecTyCon TcKind -- Used temporarily, during kind checking, for the
- | ARecClass TcKind -- tycons and clases in this recursive group
+ = AGlobal TyThing -- Used only in the return type of a lookup
+
+ | ATcId TcId -- Ids defined in this module; may not be fully zonked
+ ThLevel
+ Bool -- True <=> apply the type refinement to me
+
+ | ATyVar Name TcType -- The type to which the lexically scoped type vaiable
+ -- is currently refined. We only need the Name
+ -- for error-message purposes
+
+ | 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 (AGlobal g) = ppr g
+ ppr (ATcId g tl rig) = text "Identifier" <>
+ ifPprDebug (brackets (ppr g <> comma <> ppr tl <+> ppr rig))
+ ppr (ATyVar tv _) = text "Type variable" <+> quotes (ppr tv)
+ 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}
%************************************************************************
%* *
- EntityUsage
-%* *
-%************************************************************************
-
-EntityUsage tells what things are actually need in order to compile this
-module. It is used for generating the usage-version field of the ModIface.
-
-Note that we do not record version info for entities from
-other (non-home) packages. If the package changes, GHC doesn't help.
-
-\begin{code}
-type EntityUsage = NameSet
- -- The Names are all the (a) home-package
- -- (b) "big" (i.e. no data cons, class ops)
- -- (c) non-locally-defined
- -- (d) non-wired-in
- -- names that have been slurped in so far.
- -- This is used to generate the "usage" information for this module.
-
-emptyUsages :: EntityUsage
-emptyUsages = emptyNameSet
-\end{code}
-
-
-%************************************************************************
-%* *
Operations over ImportAvails
%* *
%************************************************************************
\begin{code}
data ImportAvails
= ImportAvails {
- imp_env :: AvailEnv,
- -- All the things that are available from the import
- -- Its domain is all the "main" things;
- -- i.e. *excluding* class ops and constructors
- -- (which appear inside their parent AvailTC)
-
- imp_qual :: ModuleEnv AvailEnv,
- -- Used to figure out "module M" export specifiers
+ imp_env :: ModuleEnv NameSet,
+ -- All the things imported, classified by
+ -- the *module qualifier* for its import
+ -- e.g. import List as Foo
+ -- would add a binding Foo |-> ...stuff from List...
+ -- to imp_env.
+ --
+ -- We need to classify them like this so that we can figure out
+ -- "module M" export specifiers in an export list
-- (see 1.4 Report Section 5.1.1). Ultimately, we want to find
-- everything that is unambiguously in scope as 'M.x'
-- and where plain 'x' is (perhaps ambiguously) in scope.
-- So the starting point is all things that are in scope as 'M.x',
-- which is what this field tells us.
- --
- -- Domain is the *module qualifier* for imports.
- -- e.g. import List as Foo
- -- would add a binding Foo |-> ...stuff from List...
- -- to imp_qual.
- -- We keep the stuff as an AvailEnv so that it's easy to
- -- combine stuff coming from different (unqualified)
- -- imports of the same module
- imp_mods :: ModuleEnv (Module, Maybe Bool),
+ 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 (ModuleName, IsBootInterface),
+ imp_dep_mods :: ModuleEnv (Module, IsBootInterface),
-- Home-package modules needed by the module being compiled
--
- -- It doesn't matter whether any of these dependencies are actually
- -- *used* when compiling the module; they are listed if they are below
- -- it at all. For example, suppose M imports A which imports X. Then
- -- compiling M might not need to consult X.hi, but X is still listed
- -- in M's dependencies.
-
- imp_dep_pkgs :: [PackageName],
+ -- It doesn't matter whether any of these dependencies
+ -- are actually *used* when compiling the module; they
+ -- are listed if they are below it at all. For
+ -- example, suppose M imports A which imports X. Then
+ -- compiling M might not need to consult X.hi, but X
+ -- is still listed in M's dependencies.
+
+ imp_dep_pkgs :: [PackageId],
-- Packages needed by the module being compiled, whether
-- directly, or via other modules in this package, or via
-- modules imported from other packages.
- imp_orphs :: [ModuleName]
+ imp_orphs :: [Module]
-- Orphan modules below us in the import tree
}
-mkModDeps :: [(ModuleName, IsBootInterface)]
- -> ModuleEnv (ModuleName, IsBootInterface)
+mkModDeps :: [(Module, IsBootInterface)]
+ -> ModuleEnv (Module, IsBootInterface)
mkModDeps deps = foldl add emptyModuleEnv deps
where
- add env elt@(m,_) = extendModuleEnvByName env m elt
+ add env elt@(m,_) = extendModuleEnv env m elt
emptyImportAvails :: ImportAvails
-emptyImportAvails = ImportAvails { imp_env = emptyAvailEnv,
- imp_qual = emptyModuleEnv,
+emptyImportAvails = ImportAvails { imp_env = emptyModuleEnv,
imp_mods = emptyModuleEnv,
imp_dep_mods = emptyModuleEnv,
imp_dep_pkgs = [],
plusImportAvails :: ImportAvails -> ImportAvails -> ImportAvails
plusImportAvails
- (ImportAvails { imp_env = env1, imp_qual = unqual1, imp_mods = mods1,
+ (ImportAvails { imp_env = env1, imp_mods = mods1,
imp_dep_mods = dmods1, imp_dep_pkgs = dpkgs1, imp_orphs = orphs1 })
- (ImportAvails { imp_env = env2, imp_qual = unqual2, imp_mods = mods2,
+ (ImportAvails { imp_env = env2, imp_mods = mods2,
imp_dep_mods = dmods2, imp_dep_pkgs = dpkgs2, imp_orphs = orphs2 })
- = ImportAvails { imp_env = env1 `plusAvailEnv` env2,
- imp_qual = plusModuleEnv_C plusAvailEnv unqual1 unqual2,
+ = ImportAvails { imp_env = plusModuleEnv_C unionNameSets env1 env2,
imp_mods = mods1 `plusModuleEnv` mods2,
imp_dep_mods = plusModuleEnv_C plus_mod_dep dmods1 dmods2,
imp_dep_pkgs = dpkgs1 `unionLists` dpkgs2,
\begin{code}
data Inst
= Dict
- Id
+ Name
TcPredType
InstLoc
TcThetaType -- The (types of the) dictionaries to which the function
-- must be applied to get the method
- TcTauType -- The tau-type of the method
-
InstLoc
-- INVARIANT 1: in (Method u f tys theta tau loc)
-- 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
- 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
+ Name
+ (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}
EQ -> True
other -> False
-cmpInst (Dict _ pred1 _) (Dict _ pred2 _) = pred1 `tcCmpPred` pred2
-cmpInst (Dict _ _ _) other = LT
+cmpInst (Dict _ pred1 _) (Dict _ pred2 _) = pred1 `tcCmpPred` pred2
+cmpInst (Dict _ _ _) other = LT
-cmpInst (Method _ _ _ _ _ _) (Dict _ _ _) = GT
-cmpInst (Method _ id1 tys1 _ _ _) (Method _ id2 tys2 _ _ _) = (id1 `compare` id2) `thenCmp` (tys1 `tcCmpTypes` tys2)
-cmpInst (Method _ _ _ _ _ _) other = LT
+cmpInst (Method _ _ _ _ _) (Dict _ _ _) = GT
+cmpInst (Method _ id1 tys1 _ _) (Method _ id2 tys2 _ _) = (id1 `compare` id2) `thenCmp` (tys1 `tcCmpTypes` tys2)
+cmpInst (Method _ _ _ _ _) other = LT
-cmpInst (LitInst _ _ _ _) (Dict _ _ _) = GT
-cmpInst (LitInst _ _ _ _) (Method _ _ _ _ _ _) = GT
-cmpInst (LitInst _ lit1 ty1 _) (LitInst _ lit2 ty2 _) = (lit1 `compare` lit2) `thenCmp` (ty1 `tcCmpType` ty2)
+cmpInst (LitInst _ _ _ _) (Dict _ _ _) = GT
+cmpInst (LitInst _ _ _ _) (Method _ _ _ _ _) = GT
+cmpInst (LitInst _ lit1 ty1 _) (LitInst _ lit2 ty2 _) = (lit1 `compare` lit2) `thenCmp` (ty1 `tcCmpType` ty2)
\end{code}
%************************************************************************
\begin{code}
+-- FIXME: Rename this. It clashes with (Located (IE ...))
type LIE = Bag Inst
isEmptyLIE = isEmptyBag
instLocSrcSpan (InstLoc _ src_span _) = src_span
data InstOrigin
- = OccurrenceOf Name -- Occurrence of an overloaded identifier
+ = SigOrigin SkolemInfo -- Pattern, class decl, inst decl etc;
+ -- Places that bind type variables and introduce
+ -- available constraints
- | IPOccOrigin (IPName Name) -- Occurrence of an implicit parameter
| IPBindOrigin (IPName Name) -- Binding site of an implicit parameter
- | RecordUpdOrigin
-
- | 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
-
- | LiteralOrigin HsOverLit -- Occurrence of a literal
+ | IPOccOrigin (IPName Name) -- Occurrence of an implicit parameter
- | PatOrigin (Pat Name)
+ | LiteralOrigin (HsOverLit Name) -- Occurrence of a literal
| 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
-
- | DoOrigin -- The monad for a do expression
- | ProcOrigin -- A proc expression
+ | InstSigOrigin -- A dict occurrence arising from instantiating
+ -- a polymorphic type during a subsumption check
- | 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 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 (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 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) = pprSkolInfo info
\end{code}
projects / ghc-hetmet.git / blobdiff