%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1994
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TcIfaceSig]{Type checking of type signatures in interface files}
\begin{code}
-#include "HsVersions.h"
-
module TcIfaceSig ( tcInterfaceSigs ) where
-IMPORT_Trace -- ToDo: rm (debugging)
-import Outputable
-import Pretty
+#include "HsVersions.h"
+
+import HsSyn ( HsDecl(..), IfaceSig(..) )
+import TcMonad
+import TcMonoType ( tcHsType, tcHsTypeKind, tcTyVarScope )
+import TcEnv ( tcExtendTyVarEnv, tcExtendGlobalValEnv, tcSetGlobalValEnv,
+ tcLookupTyConByKey, tcLookupGlobalValueMaybe,
+ tcExplicitLookupGlobal, badCon, badPrimOp,
+ GlobalValueEnv
+ )
+import TcType ( TcKind, kindToTcKind )
-import TcMonad -- typechecking monadic machinery
-import AbsSyn -- the stuff being typechecked
+import RnHsSyn ( RenamedHsDecl )
+import HsCore
+import HsDecls ( HsIdInfo(..), HsStrictnessInfo(..) )
+import CallConv ( cCallConv )
+import Const ( Con(..), Literal(..) )
+import CoreSyn
+import CoreUtils ( coreExprType )
+import CoreUnfold
+import WwLib ( mkWrapper )
+import PrimOp ( PrimOp(..) )
-import AbsUniType ( splitType, splitTyArgs )
-import CmdLineOpts ( GlobalSwitch(..) )
-import E ( getE_CE, getE_TCE, nullGVE, unitGVE,
- plusGVE, GVE(..), E, CE(..), TCE(..), UniqFM
+import Id ( Id, mkImportedId, mkUserId,
+ isPrimitiveId_maybe, isDataConId_maybe
)
-import Errors ( confusedNameErr )
-import Id -- mkImported
-#if USE_ATTACK_PRAGMAS
-import IdInfo ( workerExists )
-#endif
-import Maybes ( Maybe(..) )
-import TcPragmas ( tcGenPragmas )
-import TVE ( nullTVE, TVE(..) )
-import TcPolyType ( tcPolyType )
-import UniqFM ( emptyUFM ) -- profiling, pragmas only
-import Util
+import IdInfo
+import DataCon ( dataConSig, dataConArgTys )
+import SpecEnv ( addToSpecEnv )
+import Type ( mkSynTy, mkTyVarTys, splitAlgTyConApp )
+import Var ( mkTyVar, tyVarKind )
+import VarEnv
+import Name ( Name, NamedThing(..) )
+import Unique ( rationalTyConKey )
+import TysWiredIn ( integerTy, stringTy )
+import ErrUtils ( pprBagOfErrors )
+import Maybes ( maybeToBool, MaybeErr(..) )
+import Outputable
+import Util ( zipWithEqual )
\end{code}
Ultimately, type signatures in interfaces will have pragmatic
signatures.
\begin{code}
-tcInterfaceSigs :: E -> [RenamedSig] -> Baby_TcM GVE
+tcInterfaceSigs :: GlobalValueEnv -- Envt to use when checking unfoldings
+ -> [RenamedHsDecl] -- Ignore non-sig-decls in these decls
+ -> TcM s [Id]
+
+
+tcInterfaceSigs unf_env (SigD (IfaceSig name ty id_infos src_loc) : rest)
+ = tcAddSrcLoc src_loc (
+ tcAddErrCtxt (ifaceSigCtxt name) (
+ tcHsType ty `thenTc` \ sigma_ty ->
+ tcIdInfo unf_env name sigma_ty noIdInfo id_infos `thenTc` \ id_info ->
+ returnTc (mkImportedId name sigma_ty id_info)
+ )) `thenTc` \ sig_id ->
+ tcInterfaceSigs unf_env rest `thenTc` \ sig_ids ->
+ returnTc (sig_id : sig_ids)
+
+tcInterfaceSigs unf_env (other_decl : rest) = tcInterfaceSigs unf_env rest
+
+tcInterfaceSigs unf_env [] = returnTc []
+\end{code}
+
+\begin{code}
+tcIdInfo unf_env name ty info info_ins
+ = foldlTc tcPrag noIdInfo info_ins
+ where
+ tcPrag info (HsArity arity) = returnTc (arity `setArityInfo` info)
+ tcPrag info (HsUpdate upd) = returnTc (upd `setUpdateInfo` info)
+ tcPrag info (HsNoCafRefs) = returnTc (NoCafRefs `setCafInfo` info)
+
+ tcPrag info (HsUnfold inline_prag maybe_expr)
+ = (case maybe_expr of
+ Just expr -> tcPragExpr unf_env name expr
+ Nothing -> returnNF_Tc Nothing
+ ) `thenNF_Tc` \ maybe_expr' ->
+ let
+ -- maybe_expr doesn't get looked at if the unfolding
+ -- is never inspected; so the typecheck doesn't even happen
+ unfold_info = case maybe_expr' of
+ Nothing -> NoUnfolding
+ Just expr' -> mkUnfolding expr'
+ info1 = unfold_info `setUnfoldingInfo` info
+
+ info2 = inline_prag `setInlinePragInfo` info1
+ in
+ returnTc info2
+
+ tcPrag info (HsStrictness strict)
+ = tcStrictness unf_env ty info strict
+
+ tcPrag info (HsSpecialise tyvars tys rhs)
+ = tcTyVarScope tyvars $ \ tyvars' ->
+ mapAndUnzipTc tcHsTypeKind tys `thenTc` \ (kinds, tys') ->
+ -- Assume that the kinds match the kinds of the
+ -- type variables of the function; this is, after all, an
+ -- interface file generated by the compiler!
+
+ tcPragExpr unf_env name rhs `thenNF_Tc` \ maybe_rhs' ->
+ let
+ -- If spec_env isn't looked at, none of this
+ -- actually takes place
+ spec_env = specInfo info
+ spec_env' = case maybe_rhs' of
+ Nothing -> spec_env
+ Just rhs' -> case addToSpecEnv True {- overlap ok -} spec_env tyvars' tys' rhs' of
+ Succeeded spec_env' -> spec_env'
+ Failed err -> pprTrace "tcIdInfo: bad specialisation"
+ (ppr name <+> ppr err) $
+ spec_env
+ in
+ returnTc (spec_env' `setSpecInfo` info)
+\end{code}
+
+\begin{code}
+tcStrictness unf_env ty info (HsStrictnessInfo demands maybe_worker)
+ = tcWorker unf_env maybe_worker `thenNF_Tc` \ maybe_worker_id ->
+ uniqSMToTcM (mkWrapper ty demands) `thenNF_Tc` \ wrap_fn ->
+ let
+ -- Watch out! We can't pull on maybe_worker_id too eagerly!
+ info' = case maybe_worker_id of
+ Just worker_id -> setUnfoldingInfo (mkUnfolding (wrap_fn worker_id)) $
+ setInlinePragInfo IWantToBeINLINEd info
+
+ Nothing -> info
+
+ has_worker = maybeToBool maybe_worker_id
+ in
+ returnTc (StrictnessInfo demands has_worker `setStrictnessInfo` info')
+
+-- Boring to write these out, but the result type differs from the arg type...
+tcStrictness unf_env ty info HsBottom
+ = returnTc (BottomGuaranteed `setStrictnessInfo` info)
+\end{code}
+
+\begin{code}
+tcWorker unf_env Nothing = returnNF_Tc Nothing
+
+tcWorker unf_env (Just (worker_name,_))
+ = returnNF_Tc (trace_maybe maybe_worker_id)
+ where
+ maybe_worker_id = tcExplicitLookupGlobal unf_env worker_name
+
+ -- The trace is so we can see what's getting dropped
+ trace_maybe Nothing = pprTrace "tcWorker failed:" (ppr worker_name) Nothing
+ trace_maybe (Just x) = Just x
+\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 :: GlobalValueEnv -> Name -> UfExpr Name -> NF_TcM s (Maybe CoreExpr)
+tcPragExpr unf_env name core_expr
+ = forkNF_Tc (
+ recoverNF_Tc no_unfolding (
+ tcSetGlobalValEnv unf_env $
+ tcCoreExpr core_expr `thenTc` \ core_expr' ->
+ returnTc (Just core_expr')
+ ))
+ where
+ -- The trace tells what wasn't available, for the benefit of
+ -- compiler hackers who want to improve it!
+ no_unfolding = getErrsTc `thenNF_Tc` \ (warns,errs) ->
+ returnNF_Tc (pprTrace "tcUnfolding failed with:"
+ (hang (ppr name) 4 (pprBagOfErrors errs))
+ Nothing)
+\end{code}
+
+
+Variables in unfoldings
+~~~~~~~~~~~~~~~~~~~~~~~
+****** Inside here we use only the Global environment, even for locally bound variables.
+****** Why? Because we know all the types and want to bind them to real Ids.
+
+\begin{code}
+tcVar :: Name -> TcM s Id
+tcVar name
+ = tcLookupGlobalValueMaybe name `thenNF_Tc` \ maybe_id ->
+ case maybe_id of {
+ Just id -> returnTc id;
+ Nothing -> failWithTc (noDecl name)
+ }
+
+noDecl name = hsep [ptext SLIT("Warning: no binding for"), ppr name]
+\end{code}
+
+UfCore expressions.
+
+\begin{code}
+tcCoreExpr :: UfExpr Name -> TcM s CoreExpr
+
+tcCoreExpr (UfType ty)
+ = tcHsTypeKind ty `thenTc` \ (_, ty') ->
+ -- It might not be of kind type
+ returnTc (Type ty')
+
+tcCoreExpr (UfVar name)
+ = tcVar name `thenTc` \ id ->
+ returnTc (Var id)
+
+tcCoreExpr (UfCon con args)
+ = tcUfCon con `thenTc` \ con' ->
+ mapTc tcCoreExpr args `thenTc` \ args' ->
+ returnTc (Con con' args')
+
+tcCoreExpr (UfTuple name args)
+ = tcUfDataCon name `thenTc` \ con ->
+ mapTc tcCoreExpr args `thenTc` \ args' ->
+ let
+ -- Put the missing type arguments back in
+ con_args = map (Type . coreExprType) args' ++ args'
+ in
+ returnTc (Con con con_args)
-tcInterfaceSigs e [] = returnB_Tc nullGVE
+tcCoreExpr (UfLam bndr body)
+ = tcCoreLamBndr bndr $ \ bndr' ->
+ tcCoreExpr body `thenTc` \ body' ->
+ returnTc (Lam bndr' body')
-tcInterfaceSigs e (sig:sigs)
- = tc_sig sig `thenB_Tc` \ gve1 ->
- tcInterfaceSigs e sigs `thenB_Tc` \ gve2 ->
- returnB_Tc (plusGVE gve1 gve2)
+tcCoreExpr (UfApp fun arg)
+ = tcCoreExpr fun `thenTc` \ fun' ->
+ tcCoreExpr arg `thenTc` \ arg' ->
+ returnTc (App fun' arg')
+
+tcCoreExpr (UfCase scrut case_bndr alts)
+ = tcCoreExpr scrut `thenTc` \ scrut' ->
+ let
+ scrut_ty = coreExprType scrut'
+ case_bndr' = mkUserId case_bndr scrut_ty
+ in
+ tcExtendGlobalValEnv [case_bndr'] $
+ mapTc (tcCoreAlt scrut_ty) alts `thenTc` \ alts' ->
+ returnTc (Case scrut' case_bndr' alts')
+
+tcCoreExpr (UfLet (UfNonRec bndr rhs) body)
+ = tcCoreExpr rhs `thenTc` \ rhs' ->
+ tcCoreValBndr bndr $ \ bndr' ->
+ tcCoreExpr body `thenTc` \ body' ->
+ returnTc (Let (NonRec bndr' rhs') body')
+
+tcCoreExpr (UfLet (UfRec pairs) body)
+ = tcCoreValBndrs bndrs $ \ bndrs' ->
+ mapTc tcCoreExpr rhss `thenTc` \ rhss' ->
+ tcCoreExpr body `thenTc` \ body' ->
+ returnTc (Let (Rec (bndrs' `zip` rhss')) body')
where
- ce = getE_CE e
- tce = getE_TCE e
-
- tc_sig (Sig name@(OtherTopId uniq full_name) ty pragmas src_loc)
- = addSrcLocB_Tc src_loc (
- tcPolyType ce tce nullTVE ty `thenB_Tc` \ sigma_ty ->
-
- fixB_Tc ( \ rec_imported_id ->
- tcGenPragmas e (Just sigma_ty) rec_imported_id pragmas
- `thenB_Tc` \ id_info ->
-
- returnB_Tc (mkImported uniq full_name sigma_ty id_info)
- ) `thenB_Tc` \ final_id ->
-
- returnB_Tc (unitGVE name final_id)
- )
-
- tc_sig (Sig odd_name _ _ src_loc)
- = getSwitchCheckerB_Tc `thenB_Tc` \ sw_chkr ->
- case odd_name of
- WiredInVal _ | sw_chkr CompilingPrelude -- OK, that's cool; ignore
- -> returnB_Tc nullGVE
- _ -> failB_Tc (confusedNameErr "Bad name on a type signature (a Prelude name?)"
- odd_name src_loc)
+ (bndrs, rhss) = unzip pairs
+
+tcCoreExpr (UfNote note expr)
+ = tcCoreExpr expr `thenTc` \ expr' ->
+ case note of
+ UfCoerce to_ty -> tcHsTypeKind to_ty `thenTc` \ (_,to_ty') ->
+ returnTc (Note (Coerce to_ty' (coreExprType expr')) expr')
+ UfInlineCall -> returnTc (Note InlineCall expr')
+ UfSCC cc -> returnTc (Note (SCC cc) expr')
+
+tcCoreNote (UfSCC cc) = returnTc (SCC cc)
+tcCoreNote UfInlineCall = returnTc InlineCall
+
+
+-- rationalTy isn't built in so, we have to construct it
+-- (the "ty" part of the incoming literal is simply bottom)
+tcUfCon (UfLitCon (NoRepRational lit _))
+ = tcLookupTyConByKey rationalTyConKey `thenNF_Tc` \ rational_tycon ->
+ let
+ rational_ty = mkSynTy rational_tycon []
+ in
+ returnTc (Literal (NoRepRational lit rational_ty))
+
+-- Similarly for integers and strings, except that they are wired in
+tcUfCon (UfLitCon (NoRepInteger lit _))
+ = returnTc (Literal (NoRepInteger lit integerTy))
+tcUfCon (UfLitCon (NoRepStr lit _))
+ = returnTc (Literal (NoRepStr lit stringTy))
+
+tcUfCon (UfLitCon other_lit)
+ = returnTc (Literal other_lit)
+
+-- The dreaded lit-lits are also similar, except here the type
+-- is read in explicitly rather than being implicit
+tcUfCon (UfLitLitCon lit ty)
+ = tcHsType ty `thenTc` \ ty' ->
+ returnTc (Literal (MachLitLit lit ty'))
+
+tcUfCon (UfDataCon name) = tcUfDataCon name
+
+tcUfCon (UfPrimOp name)
+ = tcVar name `thenTc` \ op_id ->
+ case isPrimitiveId_maybe op_id of
+ Just op -> returnTc (PrimOp op)
+ Nothing -> failWithTc (badPrimOp name)
+
+tcUfCon (UfCCallOp str casm gc)
+ = returnTc (PrimOp (CCallOp (Left str) casm gc cCallConv))
+
+tcUfDataCon name
+ = tcVar name `thenTc` \ con_id ->
+ case isDataConId_maybe con_id of
+ Just con -> returnTc (DataCon con)
+ Nothing -> failWithTc (badCon name)
\end{code}
+
+\begin{code}
+tcCoreLamBndr (UfValBinder name ty) thing_inside
+ = tcHsType ty `thenTc` \ ty' ->
+ let
+ id = mkUserId name ty'
+ in
+ tcExtendGlobalValEnv [id] $
+ thing_inside id
+
+tcCoreLamBndr (UfTyBinder name kind) thing_inside
+ = let
+ tyvar = mkTyVar name kind
+ in
+ tcExtendTyVarEnv [name] [(kindToTcKind kind, tyvar)] $
+ thing_inside tyvar
+
+tcCoreValBndr (UfValBinder name ty) thing_inside
+ = tcHsType ty `thenTc` \ ty' ->
+ let
+ id = mkUserId name ty'
+ in
+ tcExtendGlobalValEnv [id] $
+ thing_inside id
+
+tcCoreValBndrs bndrs thing_inside -- Expect them all to be ValBinders
+ = mapTc tcHsType tys `thenTc` \ tys' ->
+ let
+ ids = zipWithEqual "tcCoreValBndr" mkUserId names tys'
+ in
+ tcExtendGlobalValEnv ids $
+ thing_inside ids
+ where
+ names = [name | UfValBinder name _ <- bndrs]
+ tys = [ty | UfValBinder _ ty <- bndrs]
+\end{code}
+
+\begin{code}
+tcCoreAlt scrut_ty (UfDefault, names, rhs)
+ = ASSERT( null names )
+ tcCoreExpr rhs `thenTc` \ rhs' ->
+ returnTc (DEFAULT, [], rhs')
+
+tcCoreAlt scrut_ty (UfLitCon lit, names, rhs)
+ = ASSERT( null names )
+ tcCoreExpr rhs `thenTc` \ rhs' ->
+ returnTc (Literal lit, [], rhs')
+
+tcCoreAlt scrut_ty (UfLitLitCon str ty, names, rhs)
+ = ASSERT( null names )
+ tcCoreExpr rhs `thenTc` \ rhs' ->
+ tcHsType ty `thenTc` \ ty' ->
+ returnTc (Literal (MachLitLit str ty'), [], rhs')
+
+-- A case alternative is made quite a bit more complicated
+-- by the fact that we omit type annotations because we can
+-- work them out. True enough, but its not that easy!
+tcCoreAlt scrut_ty (UfDataCon con_name, names, rhs)
+ = tcVar con_name `thenTc` \ con_id ->
+ let
+ con = case isDataConId_maybe con_id of
+ Just con -> con
+ Nothing -> pprPanic "tcCoreAlt" (ppr con_id)
+
+ (main_tyvars, _, ex_tyvars, _, _, _) = dataConSig con
+
+ (tycon, inst_tys, cons) = splitAlgTyConApp scrut_ty
+ ex_tyvars' = [mkTyVar name (tyVarKind tv) | (name,tv) <- names `zip` ex_tyvars]
+ ex_tys' = mkTyVarTys ex_tyvars'
+ arg_tys = dataConArgTys con (inst_tys ++ ex_tys')
+ id_names = drop (length ex_tyvars) names
+ arg_ids
+#ifdef DEBUG
+ | length id_names /= length arg_tys
+ = pprPanic "tcCoreAlts" (ppr (con_name, names, rhs) $$
+ (ppr main_tyvars <+> ppr ex_tyvars) $$
+ ppr arg_tys)
+ | otherwise
+#endif
+ = zipWithEqual "tcCoreAlts" mkUserId id_names arg_tys
+ in
+ ASSERT( con `elem` cons && length inst_tys == length main_tyvars )
+ tcExtendTyVarEnv (map getName ex_tyvars')
+ [ (kindToTcKind (tyVarKind tv), tv)
+ | tv <- ex_tyvars'] $
+ tcExtendGlobalValEnv arg_ids $
+ tcCoreExpr rhs `thenTc` \ rhs' ->
+ returnTc (DataCon con, ex_tyvars' ++ arg_ids, rhs')
+\end{code}
+
+\begin{code}
+ifaceSigCtxt sig_name
+ = hsep [ptext SLIT("In an interface-file signature for"), ppr sig_name]
+\end{code}
+