%
-% (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, tcVar, tcCoreExpr, tcCoreLamBndrs ) where
-module TcIfaceSig ( tcInterfaceSigs ) where
+#include "HsVersions.h"
-IMPORT_Trace -- ToDo: rm (debugging)
-import Outputable
-import Pretty
+import HsSyn ( TyClDecl(..), HsTupCon(..) )
+import TcMonad
+import TcMonoType ( tcIfaceType )
+import TcEnv ( RecTcEnv, tcExtendTyVarEnv,
+ tcExtendGlobalValEnv, tcSetEnv, tcEnvIds,
+ tcLookupGlobal_maybe, tcLookupRecId_maybe
+ )
-import TcMonad -- typechecking monadic machinery
-import AbsSyn -- the stuff being typechecked
+import RnHsSyn ( RenamedTyClDecl )
+import HsCore
+import Literal ( Literal(..) )
+import CoreSyn
+import CoreUtils ( exprType )
+import CoreUnfold
+import CoreLint ( lintUnfolding )
+import WorkWrap ( mkWrapper )
-import AbsUniType ( splitType, splitTyArgs )
-import CmdLineOpts ( GlobalSwitch(..) )
-import E ( getE_CE, getE_TCE, nullGVE, unitGVE,
- plusGVE, GVE(..), E, CE(..), TCE(..), UniqFM
- )
-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 Id ( Id, mkVanillaGlobal, mkLocalId, idName, isDataConWrapId_maybe )
+import Module ( Module )
+import MkId ( mkFCallId )
+import IdInfo
+import TyCon ( tyConDataCons )
+import DataCon ( DataCon, dataConId, dataConSig, dataConArgTys )
+import Type ( mkTyVarTys, splitTyConApp )
+import TysWiredIn ( tupleCon )
+import Var ( mkTyVar, tyVarKind )
+import Name ( Name, nameIsLocalOrFrom )
+import Demand ( wwLazy )
+import ErrUtils ( pprBagOfErrors )
+import Outputable
+import Util ( zipWithEqual )
+import HscTypes ( TyThing(..) )
\end{code}
Ultimately, type signatures in interfaces will have pragmatic
signatures.
\begin{code}
-tcInterfaceSigs :: E -> [RenamedSig] -> Baby_TcM GVE
+tcInterfaceSigs :: RecTcEnv -- Envt to use when checking unfoldings
+ -> Module -- This module
+ -> [RenamedTyClDecl] -- Ignore non-sig-decls in these decls
+ -> TcM [Id]
+
+
+tcInterfaceSigs unf_env mod decls
+ = listTc [ do_one name ty id_infos src_loc
+ | IfaceSig {tcdName = name, tcdType = ty, tcdIdInfo = id_infos, tcdLoc =src_loc} <- decls]
+ where
+ in_scope_vars = filter (nameIsLocalOrFrom mod . idName) (tcEnvIds unf_env)
+ -- Oops: using isLocalId instead can give a black hole
+ -- because it looks at the idinfo
+
+ -- When we have hi-boot files, an unfolding might refer to
+ -- something defined in this module, so we must build a
+ -- suitable in-scope set. This thunk will only be poked
+ -- if -dcore-lint is on.
+
+ do_one name ty id_infos src_loc
+ = tcAddSrcLoc src_loc $
+ tcAddErrCtxt (ifaceSigCtxt name) $
+ tcIfaceType ty `thenTc` \ sigma_ty ->
+ tcIdInfo unf_env in_scope_vars name
+ sigma_ty id_infos `thenTc` \ id_info ->
+ returnTc (mkVanillaGlobal name sigma_ty id_info)
+\end{code}
+
+\begin{code}
+tcIdInfo unf_env in_scope_vars name ty info_ins
+ = foldlTc tcPrag init_info info_ins
+ where
+ -- set the CgInfo to something sensible but uninformative before
+ -- we start, because the default CgInfo is a panic.
+ init_info = vanillaIdInfo `setCgInfo` vanillaCgInfo
+
+ tcPrag info (HsNoCafRefs) = returnTc (info `setCafInfo` NoCafRefs)
+ tcPrag info HsCprInfo = returnTc (info `setCprInfo` ReturnsCPR)
+
+ tcPrag info (HsArity arity) =
+ returnTc (info `setArityInfo` (ArityExactly arity)
+ `setCgArity` arity)
+
+ tcPrag info (HsUnfold inline_prag expr)
+ = tcPragExpr unf_env name in_scope_vars expr `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' -> mkTopUnfolding expr'
+ info1 = info `setUnfoldingInfo` unfold_info
+ info2 = info1 `setInlinePragInfo` inline_prag
+ in
+ returnTc info2
+
+ tcPrag info (HsStrictness strict_info)
+ = returnTc (info `setStrictnessInfo` strict_info)
+
+ tcPrag info (HsWorker nm arity)
+ = tcWorkerInfo unf_env ty info nm arity
+\end{code}
+
+\begin{code}
+tcWorkerInfo unf_env ty info worker_name arity
+ = uniqSMToTcM (mkWrapper ty arity demands res_bot cpr_info) `thenNF_Tc` \ wrap_fn ->
+ let
+ -- Watch out! We can't pull on unf_env too eagerly!
+ info' = case tcLookupRecId_maybe unf_env worker_name of
+ Just worker_id ->
+ info `setUnfoldingInfo` mkTopUnfolding (wrap_fn worker_id)
+ `setWorkerInfo` HasWorker worker_id arity
+
+ Nothing -> pprTrace "tcWorkerInfo failed:"
+ (ppr worker_name) info
+ in
+ returnTc info'
+ where
+ -- We are relying here on cpr and strictness info always appearing
+ -- before worker info, fingers crossed ....
+ cpr_info = cprInfo info
+
+ (demands, res_bot)
+ = case strictnessInfo info of
+ StrictnessInfo d r -> (d,r)
+ _ -> (take arity (repeat wwLazy),False)
+ -- Noncommittal
+\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 unf_env name in_scope_vars expr
+ = tcDelay unf_env doc $
+ tcCoreExpr expr `thenTc` \ core_expr' ->
-tcInterfaceSigs e [] = returnB_Tc nullGVE
+ -- Check for type consistency in the unfolding
+ tcGetSrcLoc `thenNF_Tc` \ src_loc ->
+ getDOptsTc `thenTc` \ dflags ->
+ case lintUnfolding dflags src_loc in_scope_vars core_expr' of
+ (Nothing,_) -> returnTc core_expr' -- ignore warnings
+ (Just fail_msg,_) -> failWithTc ((doc <+> text "failed Lint") $$ fail_msg)
+ where
+ doc = text "unfolding of" <+> ppr name
-tcInterfaceSigs e (sig:sigs)
- = tc_sig sig `thenB_Tc` \ gve1 ->
- tcInterfaceSigs e sigs `thenB_Tc` \ gve2 ->
- returnB_Tc (plusGVE gve1 gve2)
+tcDelay :: RecTcEnv -> SDoc -> TcM a -> NF_TcM (Maybe a)
+tcDelay unf_env doc thing_inside
+ = forkNF_Tc (
+ recoverNF_Tc bad_value (
+ tcSetEnv unf_env thing_inside `thenTc` \ r ->
+ returnTc (Just r)
+ ))
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)
+ -- The trace tells what wasn't available, for the benefit of
+ -- compiler hackers who want to improve it!
+ bad_value = getErrsTc `thenNF_Tc` \ (warns,errs) ->
+ returnNF_Tc (pprTrace "Failed:"
+ (hang doc 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 Id
+tcVar name
+ = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_id ->
+ case maybe_id of {
+ Just (AnId 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 CoreExpr
+
+tcCoreExpr (UfType ty)
+ = tcIfaceType ty `thenTc` \ ty' ->
+ -- It might not be of kind type
+ returnTc (Type ty')
+
+tcCoreExpr (UfVar name)
+ = tcVar name `thenTc` \ id ->
+ returnTc (Var id)
+
+tcCoreExpr (UfLit lit)
+ = returnTc (Lit lit)
+
+-- The dreaded lit-lits are also similar, except here the type
+-- is read in explicitly rather than being implicit
+tcCoreExpr (UfLitLit lit ty)
+ = tcIfaceType ty `thenTc` \ ty' ->
+ returnTc (Lit (MachLitLit lit ty'))
+
+tcCoreExpr (UfFCall cc ty)
+ = tcIfaceType ty `thenTc` \ ty' ->
+ tcGetUnique `thenNF_Tc` \ u ->
+ returnTc (Var (mkFCallId u cc ty'))
+
+tcCoreExpr (UfTuple (HsTupCon _ boxity arity) args)
+ = mapTc tcCoreExpr args `thenTc` \ args' ->
+ let
+ -- Put the missing type arguments back in
+ con_args = map (Type . exprType) args' ++ args'
+ in
+ returnTc (mkApps (Var con_id) con_args)
+ where
+ con_id = dataConId (tupleCon boxity arity)
+
+
+tcCoreExpr (UfLam bndr body)
+ = tcCoreLamBndr bndr $ \ bndr' ->
+ tcCoreExpr body `thenTc` \ body' ->
+ returnTc (Lam bndr' body')
+
+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 = exprType scrut'
+ case_bndr' = mkLocalId 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
+ (bndrs, rhss) = unzip pairs
+
+tcCoreExpr (UfNote note expr)
+ = tcCoreExpr expr `thenTc` \ expr' ->
+ case note of
+ UfCoerce to_ty -> tcIfaceType to_ty `thenTc` \ to_ty' ->
+ returnTc (Note (Coerce to_ty'
+ (exprType expr')) expr')
+ UfInlineCall -> returnTc (Note InlineCall expr')
+ UfInlineMe -> returnTc (Note InlineMe expr')
+ UfSCC cc -> returnTc (Note (SCC cc) expr')
+\end{code}
+
+\begin{code}
+tcCoreLamBndr (UfValBinder name ty) thing_inside
+ = tcIfaceType ty `thenTc` \ ty' ->
+ let
+ id = mkLocalId name ty'
+ in
+ tcExtendGlobalValEnv [id] $
+ thing_inside id
+
+tcCoreLamBndr (UfTyBinder name kind) thing_inside
+ = let
+ tyvar = mkTyVar name kind
+ in
+ tcExtendTyVarEnv [tyvar] (thing_inside tyvar)
+
+tcCoreLamBndrs [] thing_inside = thing_inside []
+tcCoreLamBndrs (b:bs) thing_inside
+ = tcCoreLamBndr b $ \ b' ->
+ tcCoreLamBndrs bs $ \ bs' ->
+ thing_inside (b':bs')
+
+tcCoreValBndr (UfValBinder name ty) thing_inside
+ = tcIfaceType ty `thenTc` \ ty' ->
+ let
+ id = mkLocalId name ty'
+ in
+ tcExtendGlobalValEnv [id] $
+ thing_inside id
+
+tcCoreValBndrs bndrs thing_inside -- Expect them all to be ValBinders
+ = mapTc tcIfaceType tys `thenTc` \ tys' ->
+ let
+ ids = zipWithEqual "tcCoreValBndr" mkLocalId 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 (UfLitAlt lit, names, rhs)
+ = ASSERT( null names )
+ tcCoreExpr rhs `thenTc` \ rhs' ->
+ returnTc (LitAlt lit, [], rhs')
+
+tcCoreAlt scrut_ty (UfLitLitAlt str ty, names, rhs)
+ = ASSERT( null names )
+ tcCoreExpr rhs `thenTc` \ rhs' ->
+ tcIfaceType ty `thenTc` \ ty' ->
+ returnTc (LitAlt (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 alt@(con, names, rhs)
+ = tcConAlt con `thenTc` \ con ->
+ let
+ (main_tyvars, _, ex_tyvars, _, _, _) = dataConSig con
+
+ (tycon, inst_tys) = splitTyConApp scrut_ty -- NB: not tcSplitTyConApp
+ -- We are looking at Core here
+ 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, names, rhs) $$
+ (ppr main_tyvars <+> ppr ex_tyvars) $$
+ ppr arg_tys)
+ | otherwise
+#endif
+ = zipWithEqual "tcCoreAlts" mkLocalId id_names arg_tys
+ in
+ ASSERT( con `elem` tyConDataCons tycon && length inst_tys == length main_tyvars )
+ tcExtendTyVarEnv ex_tyvars' $
+ tcExtendGlobalValEnv arg_ids $
+ tcCoreExpr rhs `thenTc` \ rhs' ->
+ returnTc (DataAlt con, ex_tyvars' ++ arg_ids, rhs')
+
+
+tcConAlt :: UfConAlt Name -> TcM DataCon
+tcConAlt (UfTupleAlt (HsTupCon _ boxity arity))
+ = returnTc (tupleCon boxity arity)
+
+tcConAlt (UfDataAlt con_name)
+ = tcVar con_name `thenTc` \ con_id ->
+ returnTc (case isDataConWrapId_maybe con_id of
+ Just con -> con
+ Nothing -> pprPanic "tcCoreAlt" (ppr con_id))
+\end{code}
+
+\begin{code}
+ifaceSigCtxt sig_name
+ = hsep [ptext SLIT("In an interface-file signature for"), ppr sig_name]
+\end{code}
+