%
% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 19921998
%
Type checking of type signatures in interface files
\begin{code}
module TcIface (
tcImportDecl, checkWiredInTyCon, tcHiBootIface, typecheckIface,
tcIfaceDecl, tcIfaceInst, tcIfaceFamInst, tcIfaceRules,
tcIfaceVectInfo, tcIfaceAnnotations, tcIfaceGlobal, tcExtCoreBindings
) where
#include "HsVersions.h"
import IfaceSyn
import LoadIface
import IfaceEnv
import BuildTyCl
import TcRnMonad
import TcType
import Type
import TypeRep
import HscTypes
import Annotations
import InstEnv
import FamInstEnv
import CoreSyn
import CoreUtils
import CoreUnfold
import CoreLint
import WorkWrap
import Id
import MkId
import IdInfo
import Class
import TyCon
import DataCon
import TysWiredIn
import TysPrim ( anyTyConOfKind )
import Var ( TyVar )
import BasicTypes ( nonRuleLoopBreaker )
import qualified Var
import VarEnv
import Name
import NameEnv
import OccurAnal ( occurAnalyseExpr )
import Demand ( isBottomingSig )
import Module
import UniqFM
import UniqSupply
import Outputable
import ErrUtils
import Maybes
import SrcLoc
import DynFlags
import Util
import FastString
import Control.Monad
import Data.List
\end{code}
This module takes
IfaceDecl -> TyThing
IfaceType -> Type
etc
An IfaceDecl is populated with RdrNames, and these are not renamed to
Names before typechecking, because there should be no scope errors etc.
%************************************************************************
%* *
%* tcImportDecl is the key function for "faulting in" *
%* imported things
%* *
%************************************************************************
The main idea is this. We are chugging along typechecking source code, and
find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
it in the EPS type envt. So it
1 loads GHC.Base.hi
2 gets the decl for GHC.Base.map
3 typechecks it via tcIfaceDecl
4 and adds it to the type env in the EPS
Note that DURING STEP 4, we may find that map's type mentions a type
constructor that also
Notice that for imported things we read the current version from the EPS
mutable variable. This is important in situations like
...$(e1)...$(e2)...
where the code that e1 expands to might import some defns that
also turn out to be needed by the code that e2 expands to.
\begin{code}
tcImportDecl :: Name -> TcM TyThing
tcImportDecl name
| Just thing <- wiredInNameTyThing_maybe name
= do { when (needWiredInHomeIface thing)
(initIfaceTcRn (loadWiredInHomeIface name))
; return thing }
| otherwise
= do { traceIf (text "tcImportDecl" <+> ppr name)
; mb_thing <- initIfaceTcRn (importDecl name)
; case mb_thing of
Succeeded thing -> return thing
Failed err -> failWithTc err }
importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
importDecl name
= ASSERT( not (isWiredInName name) )
do { traceIf nd_doc
; mb_iface <- ASSERT2( isExternalName name, ppr name )
loadInterface nd_doc (nameModule name) ImportBySystem
; case mb_iface of {
Failed err_msg -> return (Failed err_msg) ;
Succeeded _ -> do
{ eps <- getEps
; case lookupTypeEnv (eps_PTE eps) name of
Just thing -> return (Succeeded thing)
Nothing -> return (Failed not_found_msg)
}}}
where
nd_doc = ptext (sLit "Need decl for") <+> ppr name
not_found_msg = hang (ptext (sLit "Can't find interface-file declaration for") <+>
pprNameSpace (occNameSpace (nameOccName name)) <+> ppr name)
2 (vcat [ptext (sLit "Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
ptext (sLit "Use -ddump-if-trace to get an idea of which file caused the error")])
\end{code}
%************************************************************************
%* *
Checks for wiredin things
%* *
%************************************************************************
Note [Loading instances for wiredin things]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We need to make sure that we have at least *read* the interface files
for any module with an instance decl or RULE that we might want.
* If the instance decl is an orphan, we have a whole separate mechanism
(loadOprhanModules)
* If the instance decl not an orphan, then the act of looking at the
TyCon or Class will force in the defining module for the
TyCon/Class, and hence the instance decl
* BUT, if the TyCon is a wiredin TyCon, we don't really need its interface;
but we must make sure we read its interface in case it has instances or
rules. That is what LoadIface.loadWiredInHomeInterface does. It's called
from TcIface.{tcImportDecl, checkWiredInTyCon, ifCheckWiredInThing}
* HOWEVER, only do this for TyCons. There are no wiredin Classes. There
are some wiredin Ids, but we don't want to load their interfaces. For
example, Control.Exception.Base.recSelError is wired in, but that module
is compiled late in the base library, and we don't want to force it to
load before it's been compiled!
All of this is done by the type checker. The renamer plays no role.
(It used to, but no longer.)
\begin{code}
checkWiredInTyCon :: TyCon -> TcM ()
checkWiredInTyCon tc
| not (isWiredInName tc_name)
= return ()
| otherwise
= do { mod <- getModule
; ASSERT( isExternalName tc_name )
when (mod /= nameModule tc_name)
(initIfaceTcRn (loadWiredInHomeIface tc_name))
}
where
tc_name = tyConName tc
ifCheckWiredInThing :: TyThing -> IfL ()
ifCheckWiredInThing thing
= do { mod <- getIfModule
; let name = getName thing
; ASSERT2( isExternalName name, ppr name )
when (needWiredInHomeIface thing && mod /= nameModule name)
(loadWiredInHomeIface name) }
needWiredInHomeIface :: TyThing -> Bool
needWiredInHomeIface (ATyCon {}) = True
needWiredInHomeIface _ = False
\end{code}
%************************************************************************
%* *
Typechecking a complete interface
%* *
%************************************************************************
Suppose we discover we don't need to recompile. Then we must type
check the old interface file. This is a bit different to the
incremental type checking we do as we suck in interface files. Instead
we do things similarly as when we are typechecking source decls: we
bring into scope the type envt for the interface all at once, using a
knot. Remember, the decls aren't necessarily in dependency order
and even if they were, the type decls might be mutually recursive.
\begin{code}
typecheckIface :: ModIface
-> TcRnIf gbl lcl ModDetails
typecheckIface iface
= initIfaceTc iface $ \ tc_env_var -> do
{
ignore_prags <- doptM Opt_IgnoreInterfacePragmas
; names_w_things <- loadDecls ignore_prags (mi_decls iface)
; let type_env = mkNameEnv names_w_things
; writeMutVar tc_env_var type_env
; insts <- mapM tcIfaceInst (mi_insts iface)
; fam_insts <- mapM tcIfaceFamInst (mi_fam_insts iface)
; rules <- tcIfaceRules ignore_prags (mi_rules iface)
; anns <- tcIfaceAnnotations (mi_anns iface)
; vect_info <- tcIfaceVectInfo (mi_module iface) type_env
(mi_vect_info iface)
; exports <- ifaceExportNames (mi_exports iface)
; traceIf (vcat [text "Finished typechecking interface for" <+> ppr (mi_module iface),
text "Type envt:" <+> ppr type_env])
; return $ ModDetails { md_types = type_env
, md_insts = insts
, md_fam_insts = fam_insts
, md_rules = rules
, md_anns = anns
, md_vect_info = vect_info
, md_exports = exports
}
}
\end{code}
%************************************************************************
%* *
Type and class declarations
%* *
%************************************************************************
\begin{code}
tcHiBootIface :: HscSource -> Module -> TcRn ModDetails
tcHiBootIface hsc_src mod
| isHsBoot hsc_src
= return emptyModDetails
| otherwise
= do { traceIf (text "loadHiBootInterface" <+> ppr mod)
; mode <- getGhcMode
; if not (isOneShot mode)
then do { hpt <- getHpt
; case lookupUFM hpt (moduleName mod) of
Just info | mi_boot (hm_iface info)
-> return (hm_details info)
_ -> return emptyModDetails }
else do
{ eps <- getEps
; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
Nothing -> return emptyModDetails ;
Just (_, False) -> failWithTc moduleLoop ;
Just (_mod, True) ->
do { read_result <- findAndReadIface
need mod
True
; case read_result of
Failed err -> failWithTc (elaborate err)
Succeeded (iface, _path) -> typecheckIface iface
}}}}
where
need = ptext (sLit "Need the hi-boot interface for") <+> ppr mod
<+> ptext (sLit "to compare against the Real Thing")
moduleLoop = ptext (sLit "Circular imports: module") <+> quotes (ppr mod)
<+> ptext (sLit "depends on itself")
elaborate err = hang (ptext (sLit "Could not find hi-boot interface for") <+>
quotes (ppr mod) <> colon) 4 err
\end{code}
%************************************************************************
%* *
Type and class declarations
%* *
%************************************************************************
When typechecking a data type decl, we *lazily* (via forkM) typecheck
the constructor argument types. This is in the hope that we may never
poke on those argument types, and hence may never need to load the
interface files for types mentioned in the arg types.
E.g.
data Foo.S = MkS Baz.T
Mabye we can get away without even loading the interface for Baz!
This is not just a performance thing. Suppose we have
data Foo.S = MkS Baz.T
data Baz.T = MkT Foo.S
(in different interface files, of course).
Now, first we load and typecheck Foo.S, and add it to the type envt.
If we do explore MkS's argument, we'll load and typecheck Baz.T.
If we explore MkT's argument we'll find Foo.S already in the envt.
If we typechecked constructor args eagerly, when loading Foo.S we'd try to
typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
which isn't done yet.
All very cunning. However, there is a rather subtle gotcha which bit
me when developing this stuff. When we typecheck the decl for S, we
extend the type envt with S, MkS, and all its implicit Ids. Suppose
(a bug, but it happened) that the list of implicit Ids depended in
turn on the constructor arg types. Then the following sequence of
events takes place:
* we build a thunk <t> for the constructor arg tys
* we build a thunk for the extended type environment (depends on <t>)
* we write the extended type envt into the global EPS mutvar
Now we look something up in the type envt
* that pulls on <t>
* which reads the global type envt out of the global EPS mutvar
* but that depends in turn on <t>
It's subtle, because, it'd work fine if we typechecked the constructor args
eagerly
type envt by accident, because they look at it later.
What this means is that the implicitTyThings MUST NOT DEPEND on any of
the forkM stuff.
\begin{code}
tcIfaceDecl :: Bool
-> IfaceDecl
-> IfL TyThing
tcIfaceDecl = tc_iface_decl NoParentTyCon
tc_iface_decl :: TyConParent
-> Bool
-> IfaceDecl
-> IfL TyThing
tc_iface_decl _ ignore_prags (IfaceId {ifName = occ_name, ifType = iface_type,
ifIdDetails = details, ifIdInfo = info})
= do { name <- lookupIfaceTop occ_name
; ty <- tcIfaceType iface_type
; details <- tcIdDetails ty details
; info <- tcIdInfo ignore_prags name ty info
; return (AnId (mkGlobalId details name ty info)) }
tc_iface_decl parent _ (IfaceData {ifName = occ_name,
ifTyVars = tv_bndrs,
ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
ifCons = rdr_cons,
ifRec = is_rec,
ifGeneric = want_generic,
ifFamInst = mb_family })
= bindIfaceTyVars_AT tv_bndrs $ \ tyvars -> do
{ tc_name <- lookupIfaceTop occ_name
; tycon <- fixM ( \ tycon -> do
{ stupid_theta <- tcIfaceCtxt ctxt
; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
; mb_fam_inst <- tcFamInst mb_family
; buildAlgTyCon tc_name tyvars stupid_theta cons is_rec
want_generic gadt_syn parent mb_fam_inst
})
; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
; return (ATyCon tycon) }
tc_iface_decl parent _ (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
ifSynRhs = mb_rhs_ty,
ifSynKind = kind, ifFamInst = mb_family})
= bindIfaceTyVars_AT tv_bndrs $ \ tyvars -> do
{ tc_name <- lookupIfaceTop occ_name
; rhs_kind <- tcIfaceType kind
; rhs <- forkM (mk_doc tc_name) $
tc_syn_rhs mb_rhs_ty
; fam_info <- tcFamInst mb_family
; tycon <- buildSynTyCon tc_name tyvars rhs rhs_kind parent fam_info
; return (ATyCon tycon)
}
where
mk_doc n = ptext (sLit "Type syonym") <+> ppr n
tc_syn_rhs Nothing = return SynFamilyTyCon
tc_syn_rhs (Just ty) = do { rhs_ty <- tcIfaceType ty
; return (SynonymTyCon rhs_ty) }
tc_iface_decl _parent ignore_prags
(IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name,
ifTyVars = tv_bndrs, ifFDs = rdr_fds,
ifATs = rdr_ats, ifSigs = rdr_sigs,
ifRec = tc_isrec })
= bindIfaceTyVars tv_bndrs $ \ tyvars -> do
{ cls_name <- lookupIfaceTop occ_name
; ctxt <- tcIfaceCtxt rdr_ctxt
; sigs <- mapM tc_sig rdr_sigs
; fds <- mapM tc_fd rdr_fds
; cls <- fixM $ \ cls -> do
{ ats <- mapM (tc_iface_decl (AssocFamilyTyCon cls) ignore_prags) rdr_ats
; buildClass ignore_prags cls_name tyvars ctxt fds ats sigs tc_isrec }
; return (AClass cls) }
where
tc_sig (IfaceClassOp occ dm rdr_ty)
= do { op_name <- lookupIfaceTop occ
; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
; return (op_name, dm, op_ty) }
mk_doc op_name op_ty = ptext (sLit "Class op") <+> sep [ppr op_name, ppr op_ty]
tc_fd (tvs1, tvs2) = do { tvs1' <- mapM tcIfaceTyVar tvs1
; tvs2' <- mapM tcIfaceTyVar tvs2
; return (tvs1', tvs2') }
tc_iface_decl _ _ (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
= do { name <- lookupIfaceTop rdr_name
; return (ATyCon (mkForeignTyCon name ext_name
liftedTypeKind 0)) }
tcFamInst :: Maybe (IfaceTyCon, [IfaceType]) -> IfL (Maybe (TyCon, [Type]))
tcFamInst Nothing = return Nothing
tcFamInst (Just (fam, tys)) = do { famTyCon <- tcIfaceTyCon fam
; insttys <- mapM tcIfaceType tys
; return $ Just (famTyCon, insttys) }
tcIfaceDataCons :: Name -> TyCon -> [TyVar] -> IfaceConDecls -> IfL AlgTyConRhs
tcIfaceDataCons tycon_name tycon _ if_cons
= case if_cons of
IfAbstractTyCon -> return mkAbstractTyConRhs
IfOpenDataTyCon -> return DataFamilyTyCon
IfDataTyCon cons -> do { data_cons <- mapM tc_con_decl cons
; return (mkDataTyConRhs data_cons) }
IfNewTyCon con -> do { data_con <- tc_con_decl con
; mkNewTyConRhs tycon_name tycon data_con }
where
tc_con_decl (IfCon { ifConInfix = is_infix,
ifConUnivTvs = univ_tvs, ifConExTvs = ex_tvs,
ifConOcc = occ, ifConCtxt = ctxt, ifConEqSpec = spec,
ifConArgTys = args, ifConFields = field_lbls,
ifConStricts = stricts})
= bindIfaceTyVars univ_tvs $ \ univ_tyvars -> do
bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
{ name <- lookupIfaceTop occ
; eq_spec <- tcIfaceEqSpec spec
; theta <- tcIfaceCtxt ctxt
; arg_tys <- forkM (mk_doc name) (mapM tcIfaceType args)
; lbl_names <- mapM lookupIfaceTop field_lbls
; let orig_res_ty = mkFamilyTyConApp tycon
(substTyVars (mkTopTvSubst eq_spec) univ_tyvars)
; buildDataCon name is_infix
stricts lbl_names
univ_tyvars ex_tyvars
eq_spec theta
arg_tys orig_res_ty tycon
}
mk_doc con_name = ptext (sLit "Constructor") <+> ppr con_name
tcIfaceEqSpec :: [(OccName, IfaceType)] -> IfL [(TyVar, Type)]
tcIfaceEqSpec spec
= mapM do_item spec
where
do_item (occ, if_ty) = do { tv <- tcIfaceTyVar (occNameFS occ)
; ty <- tcIfaceType if_ty
; return (tv,ty) }
\end{code}
Note [Synonym kind loop]
~~~~~~~~~~~~~~~~~~~~~~~~
Notice that we eagerly grab the *kind* from the interface file, but
build a forkM thunk for the *rhs* (and family stuff). To see why,
consider this (Trac #2412)
M.hs: module M where { import X; data T = MkT S }
X.hs: module X where { import M; type S = T }
M.hsboot: module M where { data T }
When kindchecking M.hs we need S's kind. But we do not want to
find S's kind from (typeKind Srhs), because we don't want to look at
Srhs yet! Since S is imported from X.hi, S gets just one chance to
be defined, and we must not do that until we've finished with M.T.
Solution: record S's kind in the interface file; now we can safely
look at it.
%************************************************************************
%* *
Instances
%* *
%************************************************************************
\begin{code}
tcIfaceInst :: IfaceInst -> IfL Instance
tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
ifInstCls = cls, ifInstTys = mb_tcs })
= do { dfun <- forkM (ptext (sLit "Dict fun") <+> ppr dfun_occ) $
tcIfaceExtId dfun_occ
; let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
; return (mkImportedInstance cls mb_tcs' dfun oflag) }
tcIfaceFamInst :: IfaceFamInst -> IfL FamInst
tcIfaceFamInst (IfaceFamInst { ifFamInstTyCon = tycon,
ifFamInstFam = fam, ifFamInstTys = mb_tcs })
= do tycon' <- forkM (text ("Inst tycon") <+> ppr tycon) $
tcIfaceTyCon tycon
let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
return (mkImportedFamInst fam mb_tcs' tycon')
\end{code}
%************************************************************************
%* *
Rules
%* *
%************************************************************************
We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
are in the type environment. However, remember that typechecking a Rule may
(as a side effect) augment the type envt, and so we may need to iterate the process.
\begin{code}
tcIfaceRules :: Bool
-> [IfaceRule]
-> IfL [CoreRule]
tcIfaceRules ignore_prags if_rules
| ignore_prags = return []
| otherwise = mapM tcIfaceRule if_rules
tcIfaceRule :: IfaceRule -> IfL CoreRule
tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
ifRuleAuto = auto })
= do { ~(bndrs', args', rhs') <-
forkM (ptext (sLit "Rule") <+> ftext name) $
bindIfaceBndrs bndrs $ \ bndrs' ->
do { args' <- mapM tcIfaceExpr args
; rhs' <- tcIfaceExpr rhs
; return (bndrs', args', rhs') }
; let mb_tcs = map ifTopFreeName args
; return (Rule { ru_name = name, ru_fn = fn, ru_act = act,
ru_bndrs = bndrs', ru_args = args',
ru_rhs = occurAnalyseExpr rhs',
ru_rough = mb_tcs,
ru_auto = auto,
ru_local = False }) }
where
ifTopFreeName :: IfaceExpr -> Maybe Name
ifTopFreeName (IfaceType (IfaceTyConApp tc _ )) = Just (ifaceTyConName tc)
ifTopFreeName (IfaceApp f _) = ifTopFreeName f
ifTopFreeName (IfaceExt n) = Just n
ifTopFreeName _ = Nothing
\end{code}
%************************************************************************
%* *
Annotations
%* *
%************************************************************************
\begin{code}
tcIfaceAnnotations :: [IfaceAnnotation] -> IfL [Annotation]
tcIfaceAnnotations = mapM tcIfaceAnnotation
tcIfaceAnnotation :: IfaceAnnotation -> IfL Annotation
tcIfaceAnnotation (IfaceAnnotation target serialized) = do
target' <- tcIfaceAnnTarget target
return $ Annotation {
ann_target = target',
ann_value = serialized
}
tcIfaceAnnTarget :: IfaceAnnTarget -> IfL (AnnTarget Name)
tcIfaceAnnTarget (NamedTarget occ) = do
name <- lookupIfaceTop occ
return $ NamedTarget name
tcIfaceAnnTarget (ModuleTarget mod) = do
return $ ModuleTarget mod
\end{code}
%************************************************************************
%* *
Vectorisation information
%* *
%************************************************************************
\begin{code}
tcIfaceVectInfo :: Module -> TypeEnv -> IfaceVectInfo -> IfL VectInfo
tcIfaceVectInfo mod typeEnv (IfaceVectInfo
{ ifaceVectInfoVar = vars
, ifaceVectInfoTyCon = tycons
, ifaceVectInfoTyConReuse = tyconsReuse
})
= do { vVars <- mapM vectVarMapping vars
; tyConRes1 <- mapM vectTyConMapping tycons
; tyConRes2 <- mapM vectTyConReuseMapping tyconsReuse
; let (vTyCons, vDataCons, vPAs, vIsos) = unzip4 (tyConRes1 ++ tyConRes2)
; return $ VectInfo
{ vectInfoVar = mkVarEnv vVars
, vectInfoTyCon = mkNameEnv vTyCons
, vectInfoDataCon = mkNameEnv (concat vDataCons)
, vectInfoPADFun = mkNameEnv vPAs
, vectInfoIso = mkNameEnv vIsos
}
}
where
vectVarMapping name
= do { vName <- lookupOrig mod (mkVectOcc (nameOccName name))
; let { var = lookupVar name
; vVar = lookupVar vName
}
; return (var, (var, vVar))
}
vectTyConMapping name
= do { vName <- lookupOrig mod (mkVectTyConOcc (nameOccName name))
; paName <- lookupOrig mod (mkPADFunOcc (nameOccName name))
; isoName <- lookupOrig mod (mkVectIsoOcc (nameOccName name))
; let { tycon = lookupTyCon name
; vTycon = lookupTyCon vName
; paTycon = lookupVar paName
; isoTycon = lookupVar isoName
}
; vDataCons <- mapM vectDataConMapping (tyConDataCons tycon)
; return ((name, (tycon, vTycon)),
vDataCons,
(vName, (vTycon, paTycon)),
(name, (tycon, isoTycon)))
}
vectTyConReuseMapping name
= do { paName <- lookupOrig mod (mkPADFunOcc (nameOccName name))
; isoName <- lookupOrig mod (mkVectIsoOcc (nameOccName name))
; let { tycon = lookupTyCon name
; paTycon = lookupVar paName
; isoTycon = lookupVar isoName
; vDataCons = [ (dataConName dc, (dc, dc))
| dc <- tyConDataCons tycon]
}
; return ((name, (tycon, tycon)),
vDataCons,
(name, (tycon, paTycon)),
(name, (tycon, isoTycon)))
}
vectDataConMapping datacon
= do { let name = dataConName datacon
; vName <- lookupOrig mod (mkVectDataConOcc (nameOccName name))
; let vDataCon = lookupDataCon vName
; return (name, (datacon, vDataCon))
}
lookupVar name = case lookupTypeEnv typeEnv name of
Just (AnId var) -> var
Just _ ->
panic "TcIface.tcIfaceVectInfo: not an id"
Nothing ->
panic "TcIface.tcIfaceVectInfo: unknown name"
lookupTyCon name = case lookupTypeEnv typeEnv name of
Just (ATyCon tc) -> tc
Just _ ->
panic "TcIface.tcIfaceVectInfo: not a tycon"
Nothing ->
panic "TcIface.tcIfaceVectInfo: unknown name"
lookupDataCon name = case lookupTypeEnv typeEnv name of
Just (ADataCon dc) -> dc
Just _ ->
panic "TcIface.tcIfaceVectInfo: not a datacon"
Nothing ->
panic "TcIface.tcIfaceVectInfo: unknown name"
\end{code}
%************************************************************************
%* *
Types
%* *
%************************************************************************
\begin{code}
tcIfaceType :: IfaceType -> IfL Type
tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
tcIfaceTypes :: [IfaceType] -> IfL [Type]
tcIfaceTypes tys = mapM tcIfaceType tys
tcIfacePredType :: IfacePredType -> IfL PredType
tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
tcIfacePredType (IfaceEqPred t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (EqPred t1' t2') }
tcIfaceCtxt :: IfaceContext -> IfL ThetaType
tcIfaceCtxt sts = mapM tcIfacePredType sts
\end{code}
%************************************************************************
%* *
Core
%* *
%************************************************************************
\begin{code}
tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
tcIfaceExpr (IfaceType ty)
= Type <$> tcIfaceType ty
tcIfaceExpr (IfaceLcl name)
= Var <$> tcIfaceLclId name
tcIfaceExpr (IfaceTick modName tickNo)
= Var <$> tcIfaceTick modName tickNo
tcIfaceExpr (IfaceExt gbl)
= Var <$> tcIfaceExtId gbl
tcIfaceExpr (IfaceLit lit)
= return (Lit lit)
tcIfaceExpr (IfaceFCall cc ty) = do
ty' <- tcIfaceType ty
u <- newUnique
return (Var (mkFCallId u cc ty'))
tcIfaceExpr (IfaceTuple boxity args) = do
args' <- mapM tcIfaceExpr args
let con_args = map (Type . exprType) args' ++ args'
return (mkApps (Var con_id) con_args)
where
arity = length args
con_id = dataConWorkId (tupleCon boxity arity)
tcIfaceExpr (IfaceLam bndr body)
= bindIfaceBndr bndr $ \bndr' ->
Lam bndr' <$> tcIfaceExpr body
tcIfaceExpr (IfaceApp fun arg)
= App <$> tcIfaceExpr fun <*> tcIfaceExpr arg
tcIfaceExpr (IfaceCase scrut case_bndr ty alts) = do
scrut' <- tcIfaceExpr scrut
case_bndr_name <- newIfaceName (mkVarOccFS case_bndr)
let
scrut_ty = exprType scrut'
case_bndr' = mkLocalId case_bndr_name scrut_ty
tc_app = splitTyConApp scrut_ty
extendIfaceIdEnv [case_bndr'] $ do
alts' <- mapM (tcIfaceAlt scrut' tc_app) alts
ty' <- tcIfaceType ty
return (Case scrut' case_bndr' ty' alts')
tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body) = do
rhs' <- tcIfaceExpr rhs
id <- tcIfaceLetBndr bndr
body' <- extendIfaceIdEnv [id] (tcIfaceExpr body)
return (Let (NonRec id rhs') body')
tcIfaceExpr (IfaceLet (IfaceRec pairs) body) = do
ids <- mapM tcIfaceLetBndr bndrs
extendIfaceIdEnv ids $ do
rhss' <- mapM tcIfaceExpr rhss
body' <- tcIfaceExpr body
return (Let (Rec (ids `zip` rhss')) body')
where
(bndrs, rhss) = unzip pairs
tcIfaceExpr (IfaceCast expr co) = do
expr' <- tcIfaceExpr expr
co' <- tcIfaceType co
return (Cast expr' co')
tcIfaceExpr (IfaceNote note expr) = do
expr' <- tcIfaceExpr expr
case note of
IfaceSCC cc -> return (Note (SCC cc) expr')
IfaceCoreNote n -> return (Note (CoreNote n) expr')
tcIfaceAlt :: CoreExpr -> (TyCon, [Type])
-> (IfaceConAlt, [FastString], IfaceExpr)
-> IfL (AltCon, [TyVar], CoreExpr)
tcIfaceAlt _ _ (IfaceDefault, names, rhs)
= ASSERT( null names ) do
rhs' <- tcIfaceExpr rhs
return (DEFAULT, [], rhs')
tcIfaceAlt _ _ (IfaceLitAlt lit, names, rhs)
= ASSERT( null names ) do
rhs' <- tcIfaceExpr rhs
return (LitAlt lit, [], rhs')
tcIfaceAlt scrut (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
= do { con <- tcIfaceDataCon data_occ
; when (debugIsOn && not (con `elem` tyConDataCons tycon))
(failIfM (ppr scrut $$ ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon)))
; tcIfaceDataAlt con inst_tys arg_strs rhs }
tcIfaceAlt _ (tycon, inst_tys) (IfaceTupleAlt _boxity, arg_occs, rhs)
= ASSERT2( isTupleTyCon tycon, ppr tycon )
do { let [data_con] = tyConDataCons tycon
; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
tcIfaceDataAlt :: DataCon -> [Type] -> [FastString] -> IfaceExpr
-> IfL (AltCon, [TyVar], CoreExpr)
tcIfaceDataAlt con inst_tys arg_strs rhs
= do { us <- newUniqueSupply
; let uniqs = uniqsFromSupply us
; let (ex_tvs, co_tvs, arg_ids)
= dataConRepFSInstPat arg_strs uniqs con inst_tys
all_tvs = ex_tvs ++ co_tvs
; rhs' <- extendIfaceTyVarEnv all_tvs $
extendIfaceIdEnv arg_ids $
tcIfaceExpr rhs
; return (DataAlt con, all_tvs ++ arg_ids, rhs') }
\end{code}
\begin{code}
tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind]
tcExtCoreBindings [] = return []
tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
do_one (IfaceNonRec bndr rhs) thing_inside
= do { rhs' <- tcIfaceExpr rhs
; bndr' <- newExtCoreBndr bndr
; extendIfaceIdEnv [bndr'] $ do
{ core_binds <- thing_inside
; return (NonRec bndr' rhs' : core_binds) }}
do_one (IfaceRec pairs) thing_inside
= do { bndrs' <- mapM newExtCoreBndr bndrs
; extendIfaceIdEnv bndrs' $ do
{ rhss' <- mapM tcIfaceExpr rhss
; core_binds <- thing_inside
; return (Rec (bndrs' `zip` rhss') : core_binds) }}
where
(bndrs,rhss) = unzip pairs
\end{code}
%************************************************************************
%* *
IdInfo
%* *
%************************************************************************
\begin{code}
tcIdDetails :: Type -> IfaceIdDetails -> IfL IdDetails
tcIdDetails _ IfVanillaId = return VanillaId
tcIdDetails ty IfDFunId
= return (DFunId (isNewTyCon (classTyCon cls)))
where
(_, cls, _) = tcSplitDFunTy ty
tcIdDetails _ (IfRecSelId tc naughty)
= do { tc' <- tcIfaceTyCon tc
; return (RecSelId { sel_tycon = tc', sel_naughty = naughty }) }
tcIdInfo :: Bool -> Name -> Type -> IfaceIdInfo -> IfL IdInfo
tcIdInfo ignore_prags name ty info
| ignore_prags = return vanillaIdInfo
| otherwise = case info of
NoInfo -> return vanillaIdInfo
HasInfo info -> foldlM tcPrag init_info info
where
init_info = vanillaIdInfo
tcPrag :: IdInfo -> IfaceInfoItem -> IfL IdInfo
tcPrag info HsNoCafRefs = return (info `setCafInfo` NoCafRefs)
tcPrag info (HsArity arity) = return (info `setArityInfo` arity)
tcPrag info (HsStrictness str) = return (info `setStrictnessInfo` Just str)
tcPrag info (HsInline prag) = return (info `setInlinePragInfo` prag)
tcPrag info (HsUnfold lb if_unf)
= do { unf <- tcUnfolding name ty info if_unf
; let info1 | lb = info `setOccInfo` nonRuleLoopBreaker
| otherwise = info
; return (info1 `setUnfoldingInfoLazily` unf) }
\end{code}
\begin{code}
tcUnfolding :: Name -> Type -> IdInfo -> IfaceUnfolding -> IfL Unfolding
tcUnfolding name _ info (IfCoreUnfold stable if_expr)
= do { mb_expr <- tcPragExpr name if_expr
; let unf_src = if stable then InlineStable else InlineRhs
; return (case mb_expr of
Nothing -> NoUnfolding
Just expr -> mkUnfolding unf_src
True
is_bottoming expr) }
where
is_bottoming = case strictnessInfo info of
Just sig -> isBottomingSig sig
Nothing -> False
tcUnfolding name _ _ (IfCompulsory if_expr)
= do { mb_expr <- tcPragExpr name if_expr
; return (case mb_expr of
Nothing -> NoUnfolding
Just expr -> mkCompulsoryUnfolding expr) }
tcUnfolding name _ _ (IfInlineRule arity unsat_ok boring_ok if_expr)
= do { mb_expr <- tcPragExpr name if_expr
; return (case mb_expr of
Nothing -> NoUnfolding
Just expr -> mkCoreUnfolding InlineStable True expr arity
(UnfWhen unsat_ok boring_ok))
}
tcUnfolding name ty info (IfWrapper arity wkr)
= do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
; us <- newUniqueSupply
; return (case mb_wkr_id of
Nothing -> noUnfolding
Just wkr_id -> make_inline_rule wkr_id us) }
where
doc = text "Worker for" <+> ppr name
make_inline_rule wkr_id us
= mkWwInlineRule wkr_id
(initUs_ us (mkWrapper ty strict_sig) wkr_id)
arity
strict_sig = case strictnessInfo info of
Just sig -> sig
Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
tcUnfolding name dfun_ty _ (IfDFunUnfold ops)
= do { mb_ops1 <- forkM_maybe doc $ mapM tcIfaceExpr ops
; return (case mb_ops1 of
Nothing -> noUnfolding
Just ops1 -> mkDFunUnfolding dfun_ty ops1) }
where
doc = text "Class ops for dfun" <+> ppr name
\end{code}
For unfoldings we try to do the job lazily, so that we never type check
an unfolding that isn't going to be looked at.
\begin{code}
tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
tcPragExpr name expr
= forkM_maybe doc $ do
core_expr' <- tcIfaceExpr expr
ifDOptM Opt_DoCoreLinting $ do
in_scope <- get_in_scope_ids
case lintUnfolding noSrcLoc in_scope core_expr' of
Nothing -> return ()
Just fail_msg -> pprPanic "Iface Lint failure" (hang doc 2 fail_msg)
return core_expr'
where
doc = text "Unfolding of" <+> ppr name
get_in_scope_ids
= setLclEnv () $
do { env <- getGblEnv
; case if_rec_types env of {
Nothing -> return [] ;
Just (_, get_env) -> do
{ type_env <- get_env
; return (typeEnvIds type_env) }}}
\end{code}
%************************************************************************
%* *
Getting from Names to TyThings
%* *
%************************************************************************
\begin{code}
tcIfaceGlobal :: Name -> IfL TyThing
tcIfaceGlobal name
| Just thing <- wiredInNameTyThing_maybe name
= do { ifCheckWiredInThing thing; return thing }
| otherwise
= do { env <- getGblEnv
; case if_rec_types env of {
Just (mod, get_type_env)
| nameIsLocalOrFrom mod name
-> do
{ type_env <- setLclEnv () get_type_env
; case lookupNameEnv type_env name of
Just thing -> return thing
Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
(ppr name $$ ppr type_env) }
; _ -> do
{ hsc_env <- getTopEnv
; mb_thing <- liftIO (lookupTypeHscEnv hsc_env name)
; case mb_thing of {
Just thing -> return thing ;
Nothing -> do
{ mb_thing <- importDecl name
; case mb_thing of
Failed err -> failIfM err
Succeeded thing -> return thing
}}}}}
tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
tcIfaceTyCon (IfaceAnyTc kind) = do { tc_kind <- tcIfaceType kind
; tcWiredInTyCon (anyTyConOfKind tc_kind) }
tcIfaceTyCon (IfaceTc name) = do { thing <- tcIfaceGlobal name
; return (check_tc (tyThingTyCon thing)) }
where
check_tc tc
| debugIsOn = case toIfaceTyCon tc of
IfaceTc _ -> tc
_ -> pprTrace "check_tc" (ppr tc) tc
| otherwise = tc
tcIfaceTyCon IfaceLiftedTypeKindTc = return liftedTypeKindTyCon
tcIfaceTyCon IfaceOpenTypeKindTc = return openTypeKindTyCon
tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
tcIfaceTyCon IfaceArgTypeKindTc = return argTypeKindTyCon
tcIfaceTyCon IfaceUbxTupleKindTc = return ubxTupleKindTyCon
tcWiredInTyCon :: TyCon -> IfL TyCon
tcWiredInTyCon tc = do { ifCheckWiredInThing (ATyCon tc)
; return tc }
tcIfaceClass :: Name -> IfL Class
tcIfaceClass name = do { thing <- tcIfaceGlobal name
; return (tyThingClass thing) }
tcIfaceDataCon :: Name -> IfL DataCon
tcIfaceDataCon name = do { thing <- tcIfaceGlobal name
; case thing of
ADataCon dc -> return dc
_ -> pprPanic "tcIfaceExtDC" (ppr name$$ ppr thing) }
tcIfaceExtId :: Name -> IfL Id
tcIfaceExtId name = do { thing <- tcIfaceGlobal name
; case thing of
AnId id -> return id
_ -> pprPanic "tcIfaceExtId" (ppr name$$ ppr thing) }
\end{code}
%************************************************************************
%* *
Bindings
%* *
%************************************************************************
\begin{code}
bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
bindIfaceBndr (IfaceIdBndr (fs, ty)) thing_inside
= do { name <- newIfaceName (mkVarOccFS fs)
; ty' <- tcIfaceType ty
; let id = mkLocalId name ty'
; extendIfaceIdEnv [id] (thing_inside id) }
bindIfaceBndr (IfaceTvBndr bndr) thing_inside
= bindIfaceTyVar bndr thing_inside
bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
bindIfaceBndrs [] thing_inside = thing_inside []
bindIfaceBndrs (b:bs) thing_inside
= bindIfaceBndr b $ \ b' ->
bindIfaceBndrs bs $ \ bs' ->
thing_inside (b':bs')
tcIfaceLetBndr :: IfaceLetBndr -> IfL Id
tcIfaceLetBndr (IfLetBndr fs ty info)
= do { name <- newIfaceName (mkVarOccFS fs)
; ty' <- tcIfaceType ty
; case info of
NoInfo -> return (mkLocalId name ty')
HasInfo i -> return (mkLocalIdWithInfo name ty' (tc_info i)) }
where
tc_info [] = vanillaIdInfo
tc_info (HsInline p : i) = tc_info i `setInlinePragInfo` p
tc_info (HsArity a : i) = tc_info i `setArityInfo` a
tc_info (HsStrictness s : i) = tc_info i `setStrictnessInfo` Just s
tc_info (other : i) = pprTrace "tcIfaceLetBndr: discarding unexpected IdInfo"
(ppr other) (tc_info i)
newExtCoreBndr :: IfaceLetBndr -> IfL Id
newExtCoreBndr (IfLetBndr var ty _)
= do { mod <- getIfModule
; name <- newGlobalBinder mod (mkVarOccFS var) noSrcSpan
; ty' <- tcIfaceType ty
; return (mkLocalId name ty') }
bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
bindIfaceTyVar (occ,kind) thing_inside
= do { name <- newIfaceName (mkTyVarOccFS occ)
; tyvar <- mk_iface_tyvar name kind
; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
bindIfaceTyVars bndrs thing_inside
= do { names <- newIfaceNames (map mkTyVarOccFS occs)
; tyvars <- zipWithM mk_iface_tyvar names kinds
; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
where
(occs,kinds) = unzip bndrs
mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar
mk_iface_tyvar name ifKind
= do { kind <- tcIfaceType ifKind
; if isCoercionKind kind then
return (Var.mkCoVar name kind)
else
return (Var.mkTyVar name kind) }
bindIfaceTyVars_AT :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
bindIfaceTyVars_AT [] thing_inside
= thing_inside []
bindIfaceTyVars_AT (b@(tv_occ,_) : bs) thing_inside
= bindIfaceTyVars_AT bs $ \ bs' ->
do { mb_tv <- lookupIfaceTyVar tv_occ
; case mb_tv of
Just b' -> thing_inside (b':bs')
Nothing -> bindIfaceTyVar b $ \ b' ->
thing_inside (b':bs') }
\end{code}