%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1995
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TcModule]{Typechecking a whole module}
\begin{code}
-#include "HsVersions.h"
-
module TcModule (
- tcModule,
-
- -- to make the interface self-sufficient...
- Module, Bag, CE(..), E, Binds, FixityDecl, Expr, InPat,
- RenamedPat(..), TypecheckedPat, Id, Inst, Maybe, TcResult,
- Name, ProtoName, SrcLoc, Subst, TCE(..), UniqFM,
- Error(..), Pretty(..), PprStyle, PrettyRep, InstInfo
+ typecheckModule, typecheckIface, typecheckStmt, typecheckExpr,
+ TcResults(..)
) where
-import TcMonad -- typechecking monad machinery
-import AbsSyn -- the stuff being typechecked
-
--- OLD:
---import AbsPrel ( stringTy,
--- eqStringId, neStringId, ltStringId,
--- leStringId, geStringId, gtStringId,
--- maxStringId, minStringId, tagCmpStringId,
--- dfunEqStringId, dfunOrdStringId,
--- pRELUDE_CORE
--- IF_ATTACK_PRAGMAS(COMMA mkListTy COMMA charTy)
--- )
---#if USE_ATTACK_PRAGMAS
---import PrelVals ( string_cmp_id ) -- shouldn't even be visible, really
---#endif
-import BackSubst ( applyTcSubstToBinds )
-import Bag ( unionBags, bagToList, emptyBag, listToBag )
-import CE ( nullCE, checkClassCycles, lookupCE, CE(..) )
-import CmdLineOpts ( GlobalSwitch(..) )
-import E
-import HsCore -- ****** NEED TO SEE CONSTRUCTORS ******
-import HsPragmas -- ****** NEED TO SEE CONSTRUCTORS ******
-import InstEnv
-import LIE ( unMkLIE, plusLIE, LIE )
-import Name ( Name(..) )
-import RenameAuxFuns ( GlobalNameFuns(..), GlobalNameFun(..), ProtoName, Maybe )
-import SrcLoc ( mkBuiltinSrcLoc, SrcLoc )
-import TCE ( checkTypeCycles, TCE(..), UniqFM )
-import TcBinds ( tcTopBindsAndThen )
-import TcClassDcl ( tcClassDecls1, tcClassDecls2, ClassInfo )
-import TcDefaults ( tcDefaults )
-import TcDeriv ( tcDeriving )
+#include "HsVersions.h"
+
+import CmdLineOpts ( DynFlag(..), DynFlags, dopt )
+import HsSyn ( HsBinds(..), MonoBinds(..), HsDecl(..), HsExpr(..),
+ Stmt(..), InPat(..), HsMatchContext(..), RuleDecl(..),
+ isIfaceRuleDecl, nullBinds, andMonoBindList, mkSimpleMatch
+ )
+import PrelNames ( SyntaxMap, mAIN_Name, mainName, ioTyConName, printName,
+ returnIOName, bindIOName, failIOName,
+ itName
+ )
+import MkId ( unsafeCoerceId )
+import RnHsSyn ( RenamedHsBinds, RenamedHsDecl, RenamedStmt,
+ RenamedHsExpr )
+import TcHsSyn ( TypecheckedMonoBinds, TypecheckedHsExpr,
+ TypecheckedForeignDecl, TypecheckedRuleDecl,
+ zonkTopBinds, zonkForeignExports, zonkRules, mkHsLet,
+ zonkExpr, zonkIdBndr
+ )
+
+import MkIface ( pprModDetails )
+import TcExpr ( tcMonoExpr )
+import TcMonad
+import TcType ( newTyVarTy, zonkTcType, tcInstType )
+import TcMatches ( tcStmtsAndThen )
+import TcUnify ( unifyTauTy )
+import Inst ( emptyLIE, plusLIE )
+import TcBinds ( tcTopBinds )
+import TcClassDcl ( tcClassDecls2 )
+import TcDefaults ( tcDefaults, defaultDefaultTys )
+import TcEnv ( TcEnv, RecTcEnv, InstInfo(iDFunId), tcExtendGlobalValEnv, tcLookup_maybe,
+ isLocalThing, tcSetEnv, tcSetInstEnv, initTcEnv, getTcGEnv,
+ tcExtendGlobalTypeEnv, tcLookupGlobalId, tcLookupTyCon,
+ TcTyThing(..), tcLookupId
+ )
+import TcRules ( tcIfaceRules, tcSourceRules )
+import TcForeign ( tcForeignImports, tcForeignExports )
import TcIfaceSig ( tcInterfaceSigs )
-import TcInstDcls ( tcInstDecls1, tcInstDecls2, tcSpecInstSigs, buildInstanceEnvs, InstInfo(..) )
-import TcSimplify ( tcSimplifyTop )
-import TcTyDecls ( tcTyDecls )
-import Unique -- some ClassKey stuff
-import UniqFM ( emptyUFM ) -- profiling, pragmas only
-import Util
-
-import Pretty -- Debugging
+import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
+import TcSimplify ( tcSimplifyTop, tcSimplifyInfer )
+import TcTyClsDecls ( tcTyAndClassDecls )
+
+import CoreUnfold ( unfoldingTemplate, hasUnfolding )
+import TysWiredIn ( mkListTy, unitTy )
+import Type
+import ErrUtils ( printErrorsAndWarnings, errorsFound,
+ dumpIfSet_dyn, dumpIfSet_dyn_or, showPass )
+import Id ( Id, idType, idUnfolding )
+import Module ( Module, moduleName )
+import Name ( Name )
+import NameEnv ( nameEnvElts, lookupNameEnv )
+import TyCon ( tyConGenInfo )
+import BasicTypes ( EP(..), Fixity, RecFlag(..) )
+import SrcLoc ( noSrcLoc )
+import Outputable
+import IO ( stdout )
+import HscTypes ( PersistentCompilerState(..), HomeSymbolTable,
+ PackageTypeEnv, ModIface(..),
+ ModDetails(..), DFunId,
+ TypeEnv, extendTypeEnvList,
+ TyThing(..), implicitTyThingIds,
+ mkTypeEnv
+ )
+import VarSet
\end{code}
+
+%************************************************************************
+%* *
+\subsection{The stmt interface}
+%* *
+%************************************************************************
+
\begin{code}
-tcModule :: E -- initial typechecker environment
- -> GlobalNameFuns -- final renamer info (to do derivings)
- -> RenamedModule -- input
- -> TcM ((TypecheckedBinds, -- binds from class decls; does NOT
- -- include default-methods bindings
- TypecheckedBinds, -- binds from instance decls; INCLUDES
- -- class default-methods binds
- TypecheckedBinds, -- binds from value decls
- [(Inst, TypecheckedExpr)]),
-
- ([RenamedFixityDecl], -- things for the interface generator
- [Id], -- to look at...
- CE,
- TCE,
- Bag InstInfo),
-
- FiniteMap TyCon [[Maybe UniType]],
- -- source tycon specialisation requests
-
---UNUSED: E, -- environment of total accumulated info
- E, -- environment of info due to this module only
- PprStyle -> Pretty) -- -ddump-deriving info (passed upwards)
-
-tcModule e1 renamer_name_funs
- (Module mod_name exports imports_should_be_empty fixities
- tydecls ty_sigs classdecls instdecls specinst_sigs
- default_decls valdecls sigs src_loc)
-
- = addSrcLocTc src_loc ( -- record where we're starting
-
- -- Tie the knot for inteface-file value declaration signatures
- -- This info is only used inside the knot for type-checking the
- -- pragmas, which is done lazily [ie failure just drops the pragma
- -- without having any global-failure effect].
-
- fixTc (\ ~(rec_gve_sigs, _, _, _, _, _, _, _, _, _) ->
+typecheckStmt
+ :: DynFlags
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> TypeEnv -- The interactive context's type envt
+ -> PrintUnqualified -- For error printing
+ -> Module -- Is this really needed
+ -> [Name] -- Names bound by the Stmt (empty for expressions)
+ -> (SyntaxMap,
+ RenamedStmt, -- The stmt itself
+ [RenamedHsDecl]) -- Plus extra decls it sucked in from interface files
+ -> IO (Maybe (PersistentCompilerState,
+ TypecheckedHsExpr,
+ [Id],
+ Type))
+ -- The returned [Id] is the same as the input except for
+ -- ExprStmt, in which case the returned [Name] is [itName]
+
+typecheckStmt dflags pcs hst ic_type_env unqual this_mod names (syn_map, stmt, iface_decls)
+ = typecheck dflags syn_map pcs hst unqual $
+
+ -- use the default default settings, i.e. [Integer, Double]
+ tcSetDefaultTys defaultDefaultTys $
+
+ -- Typecheck the extra declarations
+ fixTc (\ ~(unf_env, _, _, _, _) ->
+ tcImports unf_env pcs hst get_fixity this_mod iface_decls
+ ) `thenTc` \ (env, new_pcs, local_inst_info, deriv_binds, local_rules) ->
+ ASSERT( null local_inst_info && nullBinds deriv_binds && null local_rules )
+
+ tcSetEnv env $
+ tcExtendGlobalTypeEnv ic_type_env $
+
+ -- The real work is done here
+ tcUserStmt names stmt `thenTc` \ (expr, bound_ids) ->
+
+ traceTc (text "tcs 1") `thenNF_Tc_`
+ zonkExpr expr `thenNF_Tc` \ zonked_expr ->
+ mapNF_Tc zonkIdBndr bound_ids `thenNF_Tc` \ zonked_ids ->
+
+ ioToTc (dumpIfSet_dyn dflags Opt_D_dump_tc "Bound Ids" (vcat (map ppr zonked_ids))) `thenNF_Tc_`
+ ioToTc (dumpIfSet_dyn dflags Opt_D_dump_tc "Typechecked" (ppr zonked_expr)) `thenNF_Tc_`
+
+ returnTc (new_pcs, zonked_expr, zonked_ids, error "typecheckStmt: no type")
+
+ where
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity n = pprPanic "typecheckStmt" (ppr n)
+\end{code}
+
+Here is the grand plan, implemented in tcUserStmt
+
+ What you type The IO [HValue] that hscStmt returns
+ ------------- ------------------------------------
+ let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
+ bindings: [x,y,...]
+
+ pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
+ bindings: [x,y,...]
+
+ expr (of IO type) ==> expr >>= \ v -> return [v]
+ [NB: result not printed] bindings: [it]
+
+
+ expr (of non-IO type,
+ result showable) ==> let v = expr in print v >> return [v]
+ bindings: [it]
+
+ expr (of non-IO type,
+ result not showable) ==> error
+
+
+\begin{code}
+tcUserStmt :: [Name] -> RenamedStmt -> TcM (TypecheckedHsExpr, [Id])
+
+tcUserStmt names (ExprStmt expr loc)
+ = ASSERT( null names )
+ tcGetUnique `thenNF_Tc` \ uniq ->
+ let
+ fresh_it = itName uniq
+ the_bind = FunMonoBind fresh_it False
+ [ mkSimpleMatch [] expr Nothing loc ] loc
+ in
+ tryTc_ (traceTc (text "tcs 1b") `thenNF_Tc_`
+ tc_stmts [fresh_it] [
+ LetStmt (MonoBind the_bind [] NonRecursive),
+ ExprStmt (HsApp (HsVar printName) (HsVar fresh_it)) loc])
+ ( traceTc (text "tcs 1a") `thenNF_Tc_`
+ tc_stmts [fresh_it] [BindStmt (VarPatIn fresh_it) expr loc])
+
+tcUserStmt names stmt
+ = tc_stmts names [stmt]
+
+
+tc_stmts names stmts
+ = tcLookupGlobalId returnIOName `thenNF_Tc` \ return_id ->
+ tcLookupGlobalId bindIOName `thenNF_Tc` \ bind_id ->
+ tcLookupGlobalId failIOName `thenNF_Tc` \ fail_id ->
+ tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon ->
+ newTyVarTy liftedTypeKind `thenNF_Tc` \ res_ty ->
let
- e2 = plusE_GVE e1 rec_gve_sigs
+ io_ty = (\ ty -> mkTyConApp ioTyCon [ty], res_ty)
+
+ -- mk_return builds the expression
+ -- returnIO @ [()] [coerce () x, .., coerce () z]
+ mk_return ids = HsApp (TyApp (HsVar return_id) [mkListTy unitTy])
+ (ExplicitListOut unitTy (map mk_item ids))
+
+ mk_item id = HsApp (TyApp (HsVar unsafeCoerceId) [idType id, unitTy])
+ (HsVar id)
in
- -- The knot for instance information. This isn't used at all
- -- till we type-check value declarations.
- fixTc ( \ ~(rec_inst_mapper, _, _, _, _, _, _, _, _) ->
-
- -- The knot for TyCons and Classes
- fixTc ( \ ~(_, rec_tce, rec_ce, rec_datacons_gve, rec_ops_gve, _, _) ->
- let
- e3 = e2
- `plusE_GVE` rec_datacons_gve
- `plusE_GVE` rec_ops_gve
- `plusE_TCE` rec_tce
- `plusE_CE` rec_ce
- in
- -- DO THE TYPE DECLS
- -- Including the pragmas: {-# ABSTRACT TypeSyn #-}
- -- {-# SPECIALIZE data DataType ... #-}
- let
- (absty_sigs, specdata_sigs) = partition is_absty_sig ty_sigs
- is_absty_sig (AbstractTypeSig _ _) = True
- is_absty_sig (SpecDataSig _ _ _) = False
-
- is_abs_syn :: Name -> Bool -- a lookup fn for abs synonyms
- is_abs_syn n
- = n `is_elem` [ tc | (AbstractTypeSig tc _) <- absty_sigs ]
- where
- is_elem = isIn "tcModule"
-
- get_spec_sigs :: Name -> [RenamedDataTypeSig]
- get_spec_sigs n
- = [ sig | sig@(SpecDataSig tc _ _) <- specdata_sigs, n == tc]
- in
- babyTcMtoTcM (tcTyDecls e3 is_abs_syn get_spec_sigs tydecls)
- `thenTc` \ (tce, datacons_gve, tycon_specs) ->
-
- -- DO THE CLASS DECLS
- tcClassDecls1 e3 rec_inst_mapper classdecls
- `thenTc` \ (class_info, ce, ops_gve) ->
-
- -- End of TyCon/Class knot
- -- Augment whatever TCE/GVE/CE stuff was in orig_e
- returnTc (e3, tce, ce, datacons_gve, ops_gve, class_info, tycon_specs)
-
- -- End of inner fixTc
- ) `thenTc` ( \ (e3, tce_here, ce_here, _, _, class_info, tycon_specs) ->
- -- The "here" things are the extra decls defined in this
- -- module or its imports; but not including whatever was
- -- in the incoming e.
-
- -- Grab completed tce/ce and check for type/class cycles
- -- The tce/ce are now stable and lookable-at, with the
- -- exception of the instance information inside classes
- let
- ce3 = getE_CE e3
- tce3 = getE_TCE e3
- in
- checkMaybeErrTc (checkTypeCycles tce3) id `thenTc_`
- checkMaybeErrTc (checkClassCycles ce3) id `thenTc_`
-
- -- Now instance declarations
- tcInstDecls1 e3 ce3 tce3 instdecls `thenNF_Tc` \ decl_inst_info ->
-
- -- Handle "derived" instances; note that we only do derivings
- -- for things in this module; we ignore deriving decls from
- -- interfaces! We pass fixities, because they may be used in
- -- doing Text.
-
- tcDeriving mod_name renamer_name_funs decl_inst_info tce3 fixities
- `thenTc` \ (deriv_inst_info, extra_deriv_binds, ddump_deriv) ->
-
- let
- inst_info = deriv_inst_info `unionBags` decl_inst_info
- in
- -- Handle specialise instance pragmas
--- getSwitchCheckerTc `thenNF_Tc` \ sw_chkr ->
--- (if sw_chkr GlasgowExts then
- tcSpecInstSigs e3 ce3 tce3 inst_info specinst_sigs
--- else
--- returnTc emptyBag)
- `thenTc` \ spec_inst_info ->
- let
- full_inst_info = inst_info `unionBags` spec_inst_info
- in
- -- OK, now do the inst-mapper stuff
- buildInstanceEnvs full_inst_info `thenTc` \ all_insts_mapper ->
-
- returnTc (all_insts_mapper, e3, ce_here, tce_here, class_info, tycon_specs,
- full_inst_info, extra_deriv_binds, ddump_deriv)
-
- -- End of outer fixTc
- )) `thenTc` ( \ (_, e3, ce_here, tce_here, class_info, tycon_specs,
- full_inst_info, extra_deriv_binds, ddump_deriv) ->
-
- -- Default declarations
- tcDefaults e3 default_decls `thenTc` \ defaulting_tys ->
- setDefaultingTys defaulting_tys ( -- for the iface sigs...
+ traceTc (text "tcs 2") `thenNF_Tc_`
+ tcStmtsAndThen combine DoExpr io_ty stmts (
+ -- Look up the names right in the middle,
+ -- where they will all be in scope
+ mapNF_Tc tcLookupId names `thenNF_Tc` \ ids ->
+ returnTc ((ids, [ResultStmt (mk_return ids) noSrcLoc]), emptyLIE)
+ ) `thenTc` \ ((ids, tc_stmts), lie) ->
+
+ -- Simplify the context right here, so that we fail
+ -- if there aren't enough instances. Notably, when we see
+ -- e
+ -- we use tryTc_ to try it <- e
+ -- and then let it = e
+ -- It's the simplify step that rejects the first.
+
+ traceTc (text "tcs 3") `thenNF_Tc_`
+ tcSimplifyTop lie `thenTc` \ const_binds ->
+ traceTc (text "tcs 4") `thenNF_Tc_`
+
+ returnTc (mkHsLet const_binds $
+ HsDoOut DoExpr tc_stmts return_id bind_id fail_id
+ (mkTyConApp ioTyCon [mkListTy unitTy]) noSrcLoc,
+ ids)
+ where
+ combine stmt (ids, stmts) = (ids, stmt:stmts)
+\end{code}
- -- Interface type signatures
+%************************************************************************
+%* *
+\subsection{Typechecking an expression}
+%* *
+%************************************************************************
- -- We tie a knot so that the Ids read out of interfaces are in scope
- -- when we read their pragmas.
- -- What we rely on is that pragmas are typechecked lazily; if
- -- any type errors are found (ie there's an inconsistency)
- -- we silently discard the pragma
+\begin{code}
+typecheckExpr :: DynFlags
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> TypeEnv -- The interactive context's type envt
+ -> PrintUnqualified -- For error printing
+ -> Module
+ -> (SyntaxMap,
+ RenamedHsExpr, -- The expression itself
+ [RenamedHsDecl]) -- Plus extra decls it sucked in from interface files
+ -> IO (Maybe (PersistentCompilerState,
+ TypecheckedHsExpr,
+ [Id], -- always empty (matches typecheckStmt)
+ Type))
+
+typecheckExpr dflags pcs hst ic_type_env unqual this_mod (syn_map, expr, decls)
+ = typecheck dflags syn_map pcs hst unqual $
+
+ -- use the default default settings, i.e. [Integer, Double]
+ tcSetDefaultTys defaultDefaultTys $
+
+ -- Typecheck the extra declarations
+ fixTc (\ ~(unf_env, _, _, _, _) ->
+ tcImports unf_env pcs hst get_fixity this_mod decls
+ ) `thenTc` \ (env, new_pcs, local_inst_info, deriv_binds, local_rules) ->
+ ASSERT( null local_inst_info && nullBinds deriv_binds && null local_rules )
+
+ -- Now typecheck the expression
+ tcSetEnv env $
+ tcExtendGlobalTypeEnv ic_type_env $
+
+ newTyVarTy openTypeKind `thenTc` \ ty ->
+ tcMonoExpr expr ty `thenTc` \ (e', lie) ->
+ tcSimplifyInfer smpl_doc (varSetElems (tyVarsOfType ty)) lie
+ `thenTc` \ (qtvs, lie_free, dict_binds, dict_ids) ->
+ tcSimplifyTop lie_free `thenTc` \ const_binds ->
+
+ let all_expr = mkHsLet const_binds $
+ TyLam qtvs $
+ DictLam dict_ids $
+ mkHsLet dict_binds $
+ e'
+
+ all_expr_ty = mkForAllTys qtvs $
+ mkFunTys (map idType dict_ids) $
+ ty
+ in
- babyTcMtoTcM (tcInterfaceSigs e3 sigs) `thenTc` \ gve_sigs ->
+ zonkExpr all_expr `thenNF_Tc` \ zonked_expr ->
+ zonkTcType all_expr_ty `thenNF_Tc` \ zonked_ty ->
+ ioToTc (dumpIfSet_dyn dflags
+ Opt_D_dump_tc "Typechecked" (ppr zonked_expr)) `thenNF_Tc_`
+ returnTc (new_pcs, zonked_expr, [], zonked_ty)
- returnTc (gve_sigs, e3, ce_here, tce_here, class_info, tycon_specs, defaulting_tys,
- full_inst_info, extra_deriv_binds, ddump_deriv)
+ where
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity n = pprPanic "typecheckExpr" (ppr n)
- -- End of extremely outer fixTc
- ))) `thenTc` \ (_, e3, ce_here, tce_here, class_info, tycon_specs, defaulting_tys,
- full_inst_info, extra_deriv_binds, ddump_deriv) ->
+ smpl_doc = ptext SLIT("main expression")
+\end{code}
- setDefaultingTys defaulting_tys ( -- to the end...
+%************************************************************************
+%* *
+\subsection{Typechecking a module}
+%* *
+%************************************************************************
+\begin{code}
+typecheckModule
+ :: DynFlags
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> ModIface -- Iface for this module
+ -> PrintUnqualified -- For error printing
+ -> (SyntaxMap, [RenamedHsDecl])
+ -> IO (Maybe (PersistentCompilerState, TcResults))
+ -- The new PCS is Augmented with imported information,
+ -- (but not stuff from this module)
+
+data TcResults
+ = TcResults {
+ -- All these fields have info *just for this module*
+ tc_env :: TypeEnv, -- The top level TypeEnv
+ tc_insts :: [DFunId], -- Instances
+ tc_rules :: [TypecheckedRuleDecl], -- Transformation rules
+ tc_binds :: TypecheckedMonoBinds, -- Bindings
+ tc_fords :: [TypecheckedForeignDecl] -- Foreign import & exports.
+ }
+
+
+typecheckModule dflags pcs hst mod_iface unqual (syn_map, decls)
+ = do { maybe_tc_result <- typecheck dflags syn_map pcs hst unqual $
+ tcModule pcs hst get_fixity this_mod decls
+ ; printTcDump dflags unqual maybe_tc_result
+ ; return maybe_tc_result }
+ where
+ this_mod = mi_module mod_iface
+ fixity_env = mi_fixities mod_iface
+
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity nm = lookupNameEnv fixity_env nm
+
+
+tcModule :: PersistentCompilerState
+ -> HomeSymbolTable
+ -> (Name -> Maybe Fixity)
+ -> Module
+ -> [RenamedHsDecl]
+ -> TcM (PersistentCompilerState, TcResults)
+
+tcModule pcs hst get_fixity this_mod decls
+ = fixTc (\ ~(unf_env, _, _) ->
+ -- Loop back the final environment, including the fully zonked
+ -- versions of bindings from this module. In the presence of mutual
+ -- recursion, interface type signatures may mention variables defined
+ -- in this module, which is why the knot is so big
+
+ -- Type-check the type and class decls, and all imported decls
+ tcImports unf_env pcs hst get_fixity this_mod decls
+ `thenTc` \ (env, new_pcs, local_insts, deriv_binds, local_rules) ->
+
+ tcSetEnv env $
+
+ -- Foreign import declarations next
+ traceTc (text "Tc4") `thenNF_Tc_`
+ tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) ->
+ tcExtendGlobalValEnv fo_ids $
+
+ -- Default declarations
+ tcDefaults decls `thenTc` \ defaulting_tys ->
+ tcSetDefaultTys defaulting_tys $
+
-- Value declarations next.
-- We also typecheck any extra binds that came out of the "deriving" process
- -- Nota bene
- tcTopBindsAndThen
- e3
- (\ binds1 (binds2, thing) -> (binds1 `ThenBinds` binds2, thing))
- (valdecls `ThenBinds` extra_deriv_binds)
- (\ e4 ->
- -- Second pass over instance declarations,
- -- to compile the bindings themselves.
- tcInstDecls2 e4 full_inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
- tcClassDecls2 e4 class_info `thenNF_Tc` \ (lie_clasdecls, class_binds) ->
- returnTc ( (EmptyBinds, (inst_binds, class_binds, e4)),
- lie_instdecls `plusLIE` lie_clasdecls,
- () )
+ traceTc (text "Default types" <+> ppr defaulting_tys) `thenNF_Tc_`
+ traceTc (text "Tc5") `thenNF_Tc_`
+ tcTopBinds (val_binds `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) ->
+
+ -- Second pass over class and instance declarations,
+ -- plus rules and foreign exports, to generate bindings
+ tcSetEnv env $
+ tcInstDecls2 local_insts `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
+ tcClassDecls2 this_mod tycl_decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) ->
+ tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) ->
+ tcSourceRules source_rules `thenNF_Tc` \ (lie_rules, more_local_rules) ->
+
+ -- CHECK THAT main IS DEFINED WITH RIGHT TYPE, IF REQUIRED
+ traceTc (text "Tc6") `thenNF_Tc_`
+ tcCheckMain this_mod `thenTc_`
+
+ -- Deal with constant or ambiguous InstIds. How could
+ -- there be ambiguous ones? They can only arise if a
+ -- top-level decl falls under the monomorphism
+ -- restriction, and no subsequent decl instantiates its
+ -- type. (Usually, ambiguous type variables are resolved
+ -- during the generalisation step.)
+ --
+ -- Note that we must do this *after* tcCheckMain, because of the
+ -- following bizarre case:
+ -- main = return ()
+ -- Here, we infer main :: forall a. m a, where m is a free
+ -- type variable. tcCheckMain will unify it with IO, and that
+ -- must happen before tcSimplifyTop, since the latter will report
+ -- m as ambiguous
+ let
+ lie_alldecls = lie_valdecls `plusLIE`
+ lie_instdecls `plusLIE`
+ lie_clasdecls `plusLIE`
+ lie_fodecls `plusLIE`
+ lie_rules
+ in
+ tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds ->
+
+ -- Backsubstitution. This must be done last.
+ -- Even tcSimplifyTop may do some unification.
+ let
+ all_binds = val_binds `AndMonoBinds`
+ inst_binds `AndMonoBinds`
+ cls_dm_binds `AndMonoBinds`
+ const_inst_binds `AndMonoBinds`
+ foe_binds
+ in
+ traceTc (text "Tc7") `thenNF_Tc_`
+ zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) ->
+ tcSetEnv final_env $
+ -- zonkTopBinds puts all the top-level Ids into the tcGEnv
+ traceTc (text "Tc8") `thenNF_Tc_`
+ zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' ->
+ traceTc (text "Tc9") `thenNF_Tc_`
+ zonkRules more_local_rules `thenNF_Tc` \ more_local_rules' ->
+
+
+ let local_things = filter (isLocalThing this_mod) (nameEnvElts (getTcGEnv final_env))
+
+ -- Create any necessary "implicit" bindings (data constructors etc)
+ -- Should we create bindings for dictionary constructors?
+ -- They are always fully applied, and the bindings are just there
+ -- to support partial applications. But it's easier to let them through.
+ implicit_binds = andMonoBindList [ CoreMonoBind id (unfoldingTemplate unf)
+ | id <- implicitTyThingIds local_things
+ , let unf = idUnfolding id
+ , hasUnfolding unf
+ ]
+
+ local_type_env :: TypeEnv
+ local_type_env = mkTypeEnv local_things
+
+ all_local_rules = local_rules ++ more_local_rules'
+ in
+ traceTc (text "Tc10") `thenNF_Tc_`
+ returnTc (final_env,
+ new_pcs,
+ TcResults { tc_env = local_type_env,
+ tc_insts = map iDFunId local_insts,
+ tc_binds = implicit_binds `AndMonoBinds` all_binds',
+ tc_fords = foi_decls ++ foe_decls',
+ tc_rules = all_local_rules
+ }
)
+ ) `thenTc` \ (_, pcs, tc_result) ->
+ returnTc (pcs, tc_result)
+ where
+ tycl_decls = [d | TyClD d <- decls]
+ val_binds = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
+ source_rules = [d | RuleD d <- decls, not (isIfaceRuleDecl d)]
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Typechecking interface decls}
+%* *
+%************************************************************************
+
+\begin{code}
+typecheckIface
+ :: DynFlags
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> ModIface -- Iface for this module (just module & fixities)
+ -> (SyntaxMap, [RenamedHsDecl])
+ -> IO (Maybe (PersistentCompilerState, ModDetails))
+ -- The new PCS is Augmented with imported information,
+ -- (but not stuff from this module).
+
+typecheckIface dflags pcs hst mod_iface (syn_map, decls)
+ = do { maybe_tc_stuff <- typecheck dflags syn_map pcs hst alwaysQualify $
+ tcIfaceImports pcs hst get_fixity this_mod decls
+ ; printIfaceDump dflags maybe_tc_stuff
+ ; return maybe_tc_stuff }
+ where
+ this_mod = mi_module mod_iface
+ fixity_env = mi_fixities mod_iface
+
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity nm = lookupNameEnv fixity_env nm
+
+ tcIfaceImports pcs hst get_fixity this_mod decls
+ = fixTc (\ ~(unf_env, _, _, _, _) ->
+ tcImports unf_env pcs hst get_fixity this_mod decls
+ ) `thenTc` \ (env, new_pcs, local_inst_info,
+ deriv_binds, local_rules) ->
+ ASSERT(nullBinds deriv_binds)
+ let
+ local_things = filter (isLocalThing this_mod) (nameEnvElts (getTcGEnv env))
+
+ mod_details = ModDetails { md_types = mkTypeEnv local_things,
+ md_insts = map iDFunId local_inst_info,
+ md_rules = [(id,rule) | IfaceRuleOut id rule <- local_rules],
+ md_binds = [] }
+ -- All the rules from an interface are of the IfaceRuleOut form
+ in
+ returnTc (new_pcs, mod_details)
+
+tcImports :: RecTcEnv
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> (Name -> Maybe Fixity)
+ -> Module
+ -> [RenamedHsDecl]
+ -> TcM (TcEnv, PersistentCompilerState, [InstInfo],
+ RenamedHsBinds, [TypecheckedRuleDecl])
+
+-- tcImports is a slight mis-nomer.
+-- It deals with everything that could be an import:
+-- type and class decls
+-- interface signatures (checked lazily)
+-- instance decls
+-- rule decls
+-- These can occur in source code too, of course
+
+tcImports unf_env pcs hst get_fixity this_mod decls
+ -- (unf_env :: RecTcEnv) is used for type-checking interface pragmas
+ -- which is done lazily [ie failure just drops the pragma
+ -- without having any global-failure effect].
+ --
+ -- unf_env is also used to get the pragama info
+ -- for imported dfuns and default methods
+
+ = checkNoErrsTc $
+ -- tcImports recovers internally, but if anything gave rise to
+ -- an error we'd better stop now, to avoid a cascade
+
+ traceTc (text "Tc1") `thenNF_Tc_`
+ tcTyAndClassDecls unf_env tycl_decls `thenTc` \ env ->
+ tcSetEnv env $
+
+ -- Typecheck the instance decls, includes deriving
+ traceTc (text "Tc2") `thenNF_Tc_`
+ tcInstDecls1 (pcs_insts pcs) (pcs_PRS pcs)
+ hst unf_env get_fixity this_mod
+ decls `thenTc` \ (new_pcs_insts, inst_env, local_insts, deriv_binds) ->
+ tcSetInstEnv inst_env $
+
+ -- Interface type signatures
+ -- We tie a knot so that the Ids read out of interfaces are in scope
+ -- when we read their pragmas.
+ -- What we rely on is that pragmas are typechecked lazily; if
+ -- any type errors are found (ie there's an inconsistency)
+ -- we silently discard the pragma
+ traceTc (text "Tc3") `thenNF_Tc_`
+ tcInterfaceSigs unf_env this_mod tycl_decls `thenTc` \ sig_ids ->
+ tcExtendGlobalValEnv sig_ids $
+
+
+ tcIfaceRules (pcs_rules pcs) this_mod iface_rules `thenNF_Tc` \ (new_pcs_rules, local_rules) ->
+ -- When relinking this module from its interface-file decls
+ -- we'll have IfaceRules that are in fact local to this module
+ -- That's the reason we we get any local_rules out here
+
+ tcGetEnv `thenTc` \ unf_env ->
+ let
+ all_things = nameEnvElts (getTcGEnv unf_env)
+
+ -- sometimes we're compiling in the context of a package module
+ -- (on the GHCi command line, for example). In this case, we
+ -- want to treat everything we pulled in as an imported thing.
+ imported_things
+ = filter (not . isLocalThing this_mod) all_things
+
+ new_pte :: PackageTypeEnv
+ new_pte = extendTypeEnvList (pcs_PTE pcs) imported_things
+
+ new_pcs :: PersistentCompilerState
+ new_pcs = pcs { pcs_PTE = new_pte,
+ pcs_insts = new_pcs_insts,
+ pcs_rules = new_pcs_rules
+ }
+ in
+ returnTc (unf_env, new_pcs, local_insts, deriv_binds, local_rules)
+ where
+ tycl_decls = [d | TyClD d <- decls]
+ iface_rules = [d | RuleD d <- decls, isIfaceRuleDecl d]
+\end{code}
+
- `thenTc` \ ((val_binds, (inst_binds, class_binds, e4)), lie_alldecls, _) ->
+%************************************************************************
+%* *
+\subsection{Checking the type of main}
+%* *
+%************************************************************************
- -- Deal with constant or ambiguous InstIds. How could
- -- there be ambiguous ones? They can only arise if a
- -- top-level decl falls under the monomorphism
- -- restriction, and no subsequent decl instantiates its
- -- type. (Usually, ambiguous type variables are resolved
- -- during the generalisation step.)
+We must check that in module Main,
+ a) main is defined
+ b) main :: forall a1...an. IO t, for some type t
- tcSimplifyTop (unMkLIE lie_alldecls) `thenTc` \ const_inst_binds ->
+If we have
+ main = error "Urk"
+then the type of main will be
+ main :: forall a. a
+and that should pass the test too.
- -- Backsubstitution. Monomorphic top-level decls may have
- -- been instantiated by subsequent decls, and the final
- -- simplification step may have instantiated some
- -- ambiguous types. So, sadly, we need to back-substitute
- -- over the whole bunch of bindings.
+So we just instantiate the type and unify with IO t, and declare
+victory if doing so succeeds.
+
+\begin{code}
+tcCheckMain :: Module -> TcM ()
+tcCheckMain this_mod
+ | not (moduleName this_mod == mAIN_Name )
+ = returnTc ()
+
+ | otherwise
+ = -- First unify the main_id with IO t, for any old t
+ tcLookup_maybe mainName `thenNF_Tc` \ maybe_thing ->
+ case maybe_thing of
+ Just (ATcId main_id) -> check_main_ty (idType main_id)
+ other -> addErrTc noMainErr
+ where
+ check_main_ty main_ty
+ = tcInstType main_ty `thenNF_Tc` \ (tvs, theta, main_tau) ->
+ newTyVarTy liftedTypeKind `thenNF_Tc` \ arg_ty ->
+ tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon ->
+ tcAddErrCtxtM (mainTypeCtxt main_ty) $
+ if not (null theta) then
+ failWithTc empty -- Context has the error message
+ else
+ unifyTauTy main_tau (mkTyConApp ioTyCon [arg_ty])
+
+mainTypeCtxt main_ty tidy_env
+ = zonkTcType main_ty `thenNF_Tc` \ main_ty' ->
+ returnNF_Tc (tidy_env, ptext SLIT("`main' has the illegal type") <+>
+ quotes (ppr (tidyType tidy_env main_ty')))
+
+noMainErr = hsep [ptext SLIT("Module") <+> quotes (ppr mAIN_Name),
+ ptext SLIT("must include a definition for") <+> quotes (ptext SLIT("main"))]
+\end{code}
- applyTcSubstToBinds val_binds `thenNF_Tc` \ val_binds' ->
- applyTcSubstToBinds inst_binds `thenNF_Tc` \ inst_binds' ->
- applyTcSubstToBinds class_binds `thenNF_Tc` \ class_binds' ->
- -- ToDo: probably need to back-substitute over all
- -- stuff in 'e4'; we do so here over the Ids,
- -- which is probably enough. WDP 95/06
- mapNF_Tc applyTcSubstToId (getE_GlobalVals e4)
- `thenNF_Tc` \ if_global_ids ->
+%************************************************************************
+%* *
+\subsection{Interfacing the Tc monad to the IO monad}
+%* *
+%************************************************************************
- -- FINISHED AT LAST
- returnTc (
- (class_binds', inst_binds', val_binds', const_inst_binds),
+\begin{code}
+typecheck :: DynFlags
+ -> SyntaxMap
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> PrintUnqualified -- For error printing
+ -> TcM r
+ -> IO (Maybe r)
+
+typecheck dflags syn_map pcs hst unqual thing_inside
+ = do { showPass dflags "Typechecker";
+ ; env <- initTcEnv syn_map hst (pcs_PTE pcs)
+
+ ; (maybe_tc_result, errs) <- initTc dflags env thing_inside
+
+ ; printErrorsAndWarnings unqual errs
+
+ ; if errorsFound errs then
+ return Nothing
+ else
+ return maybe_tc_result
+ }
+\end{code}
- -- the next collection is just for mkInterface
- (fixities, if_global_ids, ce_here, tce_here, full_inst_info),
- tycon_specs,
+%************************************************************************
+%* *
+\subsection{Dumping output}
+%* *
+%************************************************************************
---UNUSED: e4,
+\begin{code}
+printTcDump dflags unqual Nothing = return ()
+printTcDump dflags unqual (Just (_, results))
+ = do if dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags then
+ printForUser stdout unqual (dump_tc_iface dflags results)
+ else return ()
+
+ dumpIfSet_dyn dflags Opt_D_dump_tc
+ "Typechecked" (ppr (tc_binds results))
+
+
+printIfaceDump dflags Nothing = return ()
+printIfaceDump dflags (Just (_, details))
+ = dumpIfSet_dyn_or dflags [Opt_D_dump_types, Opt_D_dump_tc]
+ "Interface" (pprModDetails details)
+
+dump_tc_iface dflags results
+ = vcat [pprModDetails (ModDetails {md_types = tc_env results,
+ md_insts = tc_insts results,
+ md_rules = [], md_binds = []}) ,
+ ppr_rules (tc_rules results),
+
+ if dopt Opt_Generics dflags then
+ ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts (tc_env results)]
+ else
+ empty
+ ]
+
+ppr_rules [] = empty
+ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
+ nest 4 (vcat (map ppr rs)),
+ ptext SLIT("#-}")]
+
+ppr_gen_tycons tcs = vcat [ptext SLIT("{-# Generic type constructor details"),
+ vcat (map ppr_gen_tycon tcs),
+ ptext SLIT("#-}")
+ ]
+
+-- x&y are now Id's, not CoreExpr's
+ppr_gen_tycon tycon
+ | Just ep <- tyConGenInfo tycon
+ = (ppr tycon <> colon) $$ nest 4 (ppr_ep ep)
+
+ | otherwise = ppr tycon <> colon <+> ptext SLIT("Not derivable")
+
+ppr_ep (EP from to)
+ = vcat [ ptext SLIT("Rep type:") <+> ppr (funResultTy from_tau),
+ ptext SLIT("From:") <+> ppr (unfoldingTemplate (idUnfolding from)),
+ ptext SLIT("To:") <+> ppr (unfoldingTemplate (idUnfolding to))
+ ]
+ where
+ (_,from_tau) = splitForAllTys (idType from)
- -- and... TCE needed for code generation; rest needed for interpreter.
- -- ToDo: still wrong: needs isLocallyDeclared run over everything
- mkE tce_here {-gve_here lve-} ce_here,
- -- NB: interpreter would probably need the gve_here stuff
- ddump_deriv
- )))
\end{code}
projects / ghc-hetmet.git / blobdiff