\section[TcIfaceSig]{Type checking of type signatures in interface files}
\begin{code}
-#include "HsVersions.h"
-
module TcIfaceSig ( tcInterfaceSigs ) where
-import Ubiq
+#include "HsVersions.h"
+import HsSyn ( HsDecl(..), IfaceSig(..) )
import TcMonad
-import TcMonoType ( tcPolyType )
-
-import HsSyn ( Sig(..), PolyType )
-import RnHsSyn ( RenamedSig(..) )
-
-import CmdLineOpts ( opt_CompilingPrelude )
-import Id ( mkImported )
-import Name ( Name(..) )
-import Pretty
-import Util ( panic )
+import TcMonoType ( tcHsType, tcHsTypeKind, tcTyVarScope )
+import TcEnv ( tcExtendTyVarEnv, tcExtendGlobalValEnv, tcSetGlobalValEnv,
+ tcLookupTyConByKey, tcLookupGlobalValueMaybe,
+ tcExplicitLookupGlobal,
+ GlobalValueEnv
+ )
+import TcKind ( TcKind, kindToTcKind )
+import RnHsSyn ( RenamedHsDecl )
+import HsCore
+import HsDecls ( HsIdInfo(..), HsStrictnessInfo(..) )
+import Literal ( Literal(..) )
+import CoreSyn
+import CoreUtils ( coreExprType )
+import CoreUnfold
+import MagicUFs ( MagicUnfoldingFun )
+import WwLib ( mkWrapper )
+import PrimOp ( PrimOp(..) )
+import CallConv ( cCallConv )
---import TcPragmas ( tcGenPragmas )
-import IdInfo ( noIdInfo )
-tcGenPragmas ty id ps = returnNF_Tc noIdInfo
+import MkId ( mkImportedId, mkUserId )
+import Id ( Id, addInlinePragma, isPrimitiveId_maybe, dataConArgTys )
+import IdInfo
+import SpecEnv ( addToSpecEnv )
+import Type ( mkSynTy, splitAlgTyConApp )
+import TyVar ( mkSysTyVar )
+import Name ( Name )
+import Unique ( rationalTyConKey, uniqueOf )
+import TysWiredIn ( integerTy )
+import ErrUtils ( pprBagOfErrors )
+import Maybes ( maybeToBool, MaybeErr(..) )
+import Outputable
+import Util ( zipWithEqual )
\end{code}
signatures.
\begin{code}
-tcInterfaceSigs :: [RenamedSig] -> TcM s [Id]
-
-tcInterfaceSigs [] = returnTc []
-
-tcInterfaceSigs (Sig name@(ValName uniq full_name) ty pragmas src_loc : sigs)
- = tcAddSrcLoc src_loc (
- tcPolyType ty `thenTc` \ sigma_ty ->
- fixTc ( \ rec_id ->
- tcGenPragmas (Just sigma_ty) rec_id pragmas
- `thenNF_Tc` \ id_info ->
- returnTc (mkImported uniq full_name sigma_ty id_info)
- )) `thenTc` \ id ->
- tcInterfaceSigs sigs `thenTc` \ sigs' ->
- returnTc (id:sigs')
-
-
-tcInterfaceSigs (Sig odd_name _ _ src_loc : sigs)
- = case odd_name of
- WiredInVal _ | opt_CompilingPrelude
- -> tcInterfaceSigs sigs
- _ -> tcAddSrcLoc src_loc $
- failTc (ifaceSigNameErr odd_name)
-
-ifaceSigNameErr name sty
- = ppHang (ppStr "Bad name in an interface type signature (a Prelude name?)")
- 4 (ppr sty name)
+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 (HsFBType fb) = returnTc (fb `setFBTypeInfo` info)
+ tcPrag info (HsArgUsage au) = returnTc (au `setArgUsageInfo` info)
+
+ tcPrag info (HsUnfold inline expr)
+ = tcPragExpr unf_env name 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' -> mkUnfolding expr'
+ info1 = unfold_info `setUnfoldingInfo` info
+
+ info2 | inline = IWantToBeINLINEd `setInlinePragInfo` info1
+ | otherwise = 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 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 (UfVar name)
+ = tcVar name `thenTc` \ id ->
+ returnTc (Var id)
+
+-- rationalTy isn't built in so we have to construct it
+-- (the "ty" part of the incoming literal is simply bottom)
+tcCoreExpr (UfLit (NoRepRational lit _))
+ = tcLookupTyConByKey rationalTyConKey `thenNF_Tc` \ rational_tycon ->
+ let
+ rational_ty = mkSynTy rational_tycon []
+ in
+ returnTc (Lit (NoRepRational lit rational_ty))
+
+-- Similarly for integers, except that it is wired in
+tcCoreExpr (UfLit (NoRepInteger lit _))
+ = returnTc (Lit (NoRepInteger lit integerTy))
+
+tcCoreExpr (UfLit other_lit)
+ = returnTc (Lit other_lit)
+
+tcCoreExpr (UfCon con args)
+ = tcVar con `thenTc` \ con_id ->
+ mapTc tcCoreArg args `thenTc` \ args' ->
+ returnTc (Con con_id args')
+
+tcCoreExpr (UfPrim prim args)
+ = tcCorePrim prim `thenTc` \ primop ->
+ mapTc tcCoreArg args `thenTc` \ args' ->
+ returnTc (Prim primop args')
+
+tcCoreExpr (UfLam bndr body)
+ = tcCoreLamBndr bndr $ \ bndr' ->
+ tcCoreExpr body `thenTc` \ body' ->
+ returnTc (Lam bndr' body')
+
+tcCoreExpr (UfApp fun arg)
+ = tcCoreExpr fun `thenTc` \ fun' ->
+ tcCoreArg arg `thenTc` \ arg' ->
+ returnTc (App fun' arg')
+
+tcCoreExpr (UfCase scrut alts)
+ = tcCoreExpr scrut `thenTc` \ scrut' ->
+ tcCoreAlts (coreExprType scrut') alts `thenTc` \ alts' ->
+ returnTc (Case scrut' 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 -> 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
+\end{code}
+
+\begin{code}
+tcCoreLamBndr (UfValBinder name ty) thing_inside
+ = tcHsType ty `thenTc` \ ty' ->
+ let
+ id = mkUserId name ty'
+ in
+ tcExtendGlobalValEnv [id] $
+ thing_inside (ValBinder id)
+
+tcCoreLamBndr (UfTyBinder name kind) thing_inside
+ = let
+ tyvar = mkSysTyVar (uniqueOf name) kind
+ in
+ tcExtendTyVarEnv [name] [(kindToTcKind kind, tyvar)] $
+ thing_inside (TyBinder 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 = map (\ (UfValBinder name _) -> name) bndrs
+ tys = map (\ (UfValBinder _ ty) -> ty) bndrs
+\end{code}
+
+\begin{code}
+tcCoreArg (UfVarArg v) = tcVar v `thenTc` \ v' -> returnTc (VarArg v')
+tcCoreArg (UfTyArg ty) = tcHsTypeKind ty `thenTc` \ (_,ty') -> returnTc (TyArg ty')
+tcCoreArg (UfLitArg lit) = returnTc (LitArg lit)
+
+tcCoreAlts scrut_ty (UfAlgAlts alts deflt)
+ = mapTc tc_alt alts `thenTc` \ alts' ->
+ tcCoreDefault scrut_ty deflt `thenTc` \ deflt' ->
+ returnTc (AlgAlts alts' deflt')
+ where
+ tc_alt (con, names, rhs)
+ = tcVar con `thenTc` \ con' ->
+ let
+ arg_tys = dataConArgTys con' inst_tys
+ (tycon, inst_tys, cons) = splitAlgTyConApp scrut_ty
+ arg_ids = zipWithEqual "tcCoreAlts" mkUserId names arg_tys
+ in
+ tcExtendGlobalValEnv arg_ids $
+ tcCoreExpr rhs `thenTc` \ rhs' ->
+ returnTc (con', arg_ids, rhs')
+
+tcCoreAlts scrut_ty (UfPrimAlts alts deflt)
+ = mapTc tc_alt alts `thenTc` \ alts' ->
+ tcCoreDefault scrut_ty deflt `thenTc` \ deflt' ->
+ returnTc (PrimAlts alts' deflt')
+ where
+ tc_alt (lit, rhs) = tcCoreExpr rhs `thenTc` \ rhs' ->
+ returnTc (lit, rhs')
+
+tcCoreDefault scrut_ty UfNoDefault = returnTc NoDefault
+tcCoreDefault scrut_ty (UfBindDefault name rhs)
+ = let
+ deflt_id = mkUserId name scrut_ty
+ in
+ tcExtendGlobalValEnv [deflt_id] $
+ tcCoreExpr rhs `thenTc` \ rhs' ->
+ returnTc (BindDefault deflt_id rhs')
+
+
+tcCorePrim (UfOtherOp op)
+ = tcVar op `thenTc` \ op_id ->
+ case isPrimitiveId_maybe op_id of
+ Just prim_op -> returnTc prim_op
+ Nothing -> pprPanic "tcCorePrim" (ppr op_id)
+
+tcCorePrim (UfCCallOp str casm gc arg_tys res_ty)
+ = mapTc tcHsType arg_tys `thenTc` \ arg_tys' ->
+ tcHsType res_ty `thenTc` \ res_ty' ->
+ returnTc (CCallOp (Left str) casm gc cCallConv arg_tys' res_ty')
\end{code}
+
+\begin{code}
+ifaceSigCtxt sig_name
+ = hsep [ptext SLIT("In an interface-file signature for"), ppr sig_name]
+\end{code}
+