\section[TcIfaceSig]{Type checking of type signatures in interface files}
\begin{code}
-module TcIfaceSig ( tcInterfaceSigs, tcDelay, tcVar, tcCoreExpr, tcCoreLamBndrs ) where
+module TcIfaceSig ( tcInterfaceSigs,
+ tcCoreExpr,
+ tcCoreLamBndrs,
+ tcCoreBinds ) where
#include "HsVersions.h"
-import HsSyn ( TyClDecl(..), HsTupCon(..) )
-import TcMonad
-import TcMonoType ( tcIfaceType )
-import TcEnv ( RecTcEnv, tcExtendTyVarEnv,
- tcExtendGlobalValEnv, tcSetEnv, tcEnvIds,
- tcLookupGlobal_maybe, tcLookupRecId_maybe
- )
+import HsSyn ( CoreDecl(..), TyClDecl(..), HsTupCon(..) )
+import TcHsSyn ( TypecheckedCoreBind )
+import TcRnTypes
+import TcRnMonad
+import TcMonoType ( tcIfaceType, kcHsSigType )
+import TcEnv ( tcExtendTyVarEnv, tcExtendGlobalValEnv, tcLookupGlobalId,
+ tcLookupDataCon )
-import RnHsSyn ( RenamedTyClDecl )
+import RnHsSyn ( RenamedCoreDecl, RenamedTyClDecl )
import HsCore
import Literal ( Literal(..) )
import CoreSyn
import CoreLint ( lintUnfolding )
import WorkWrap ( mkWrapper )
-import Id ( Id, mkVanillaGlobal, mkLocalId, idName, isDataConWrapId_maybe )
-import Module ( Module )
+import Id ( Id, mkVanillaGlobal, mkLocalId )
import MkId ( mkFCallId )
import IdInfo
-import TyCon ( tyConDataCons )
-import DataCon ( DataCon, dataConId, dataConSig, dataConArgTys )
+import TyCon ( tyConDataCons, tyConTyVars )
+import DataCon ( DataCon, dataConWorkId, dataConExistentialTyVars, dataConArgTys )
import Type ( mkTyVarTys, splitTyConApp )
import TysWiredIn ( tupleCon )
import Var ( mkTyVar, tyVarKind )
-import Name ( Name, nameIsLocalOrFrom )
-import ErrUtils ( pprBagOfErrors )
+import Name ( Name )
+import UniqSupply ( initUs_ )
import Outputable
import Util ( zipWithEqual, dropList, equalLength )
-import HscTypes ( TyThing(..) )
+import HscTypes ( typeEnvIds )
+import CmdLineOpts ( DynFlag(..) )
\end{code}
Ultimately, type signatures in interfaces will have pragmatic
signatures.
\begin{code}
-tcInterfaceSigs :: RecTcEnv -- Envt to use when checking unfoldings
- -> Module -- This module
- -> [RenamedTyClDecl] -- Ignore non-sig-decls in these decls
- -> TcM [Id]
+tcInterfaceSigs :: [RenamedTyClDecl] -- Ignore non-sig-decls in these decls
+ -> TcM TcGblEnv
-
-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]
+tcInterfaceSigs decls = fixM (tc_interface_sigs decls)
+ -- 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
+ --
+ -- NOTE ALSO: the knot is in two parts:
+ -- * Ids defined in this module are added to the typechecker envt
+ -- which is knot-tied by the fixM.
+ -- * Imported Ids are side-effected into the PCS by the
+ -- tcExtendGlobalValueEnv, so they will be seen there provided
+ -- we don't look them up too early.
+ -- In both cases, we must defer lookups until after the knot is tied
+ --
+ -- We used to have a much bigger loop (in TcRnDriver), so that the
+ -- interface pragmas could mention variables bound in this module
+ -- (by mutual recn), but
+ -- (a) the knot is tiresomely big, and
+ -- (b) it black-holes when we have Template Haskell
+ --
+ -- For (b) consider: f = $(...h....)
+ -- where h is imported, and calls f via an hi-boot file.
+ -- This is bad! But it is not seen as a staging error, because h
+ -- is indeed imported. We don't want the type-checker to black-hole
+ -- when simplifying and compiling the splice!
+ --
+ -- Simple solution: discard any unfolding that mentions a variable
+ -- bound in this module (and hence not yet processed).
+ -- The discarding happens when forkM finds a type error.
+
+tc_interface_sigs decls unf_env
+ = sequenceM [do_one d | d@(IfaceSig {}) <- decls] `thenM` \ sig_ids ->
+ tcExtendGlobalValEnv sig_ids getGblEnv
+ -- Return the extended environment
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
-
+ in_scope_vars = typeEnvIds (tcg_type_env unf_env)
-- 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 ->
+ do_one IfaceSig {tcdName = name, tcdType = ty,
+ tcdIdInfo = id_infos, tcdLoc = src_loc}
+ = addSrcLoc src_loc $
+ addErrCtxt (ifaceSigCtxt name) $
+ tcIfaceType ty `thenM` \ sigma_ty ->
tcIdInfo unf_env in_scope_vars name
- sigma_ty id_infos `thenTc` \ id_info ->
- returnTc (mkVanillaGlobal name sigma_ty id_info)
+ sigma_ty id_infos `thenM` \ id_info ->
+ returnM (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
+ = setGblEnv unf_env $
+ -- Use the knot-tied environment for the IdInfo
+ -- In particular: typechecking unfoldings and worker names
+ foldlM 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)
+ -- Set the CgInfo to something sensible but uninformative before
+ -- we start; default assumption is that it has CAFs
+ init_info = hasCafIdInfo
- tcPrag info (HsArity arity) =
- returnTc (info `setArityInfo` arity)
+ tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
+ tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
+ tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
+ tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
tcPrag info (HsUnfold inline_prag expr)
- = tcPragExpr unf_env name in_scope_vars expr `thenNF_Tc` \ maybe_expr' ->
+ = tcPragExpr name in_scope_vars expr `thenM` \ maybe_expr' ->
let
- -- maybe_expr doesn't get looked at if the unfolding
+ -- 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 `setNewStrictnessInfo` Just strict_info)
-
- tcPrag info (HsWorker nm arity)
- = tcWorkerInfo unf_env ty info nm arity
+ returnM (info `setUnfoldingInfoLazily` unfold_info
+ `setInlinePragInfo` inline_prag)
\end{code}
\begin{code}
-tcWorkerInfo unf_env ty info worker_name arity
- = uniqSMToTcM (mkWrapper ty strict_sig) `thenNF_Tc` \ wrap_fn ->
- let
+tcWorkerInfo ty info wkr_name arity
+ = forkM doc (tcVar wkr_name) `thenM` \ maybe_wkr_id ->
-- 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
+ -- Hence the forkM
+
+ -- We return without testing maybe_wkr_id, but as soon as info is
+ -- looked at we will test it. That's ok, because its outside the
+ -- knot; and there seems no big reason to further defer the
+ -- tcVar lookup. (Contrast with tcPragExpr, where postponing walking
+ -- over the unfolding until it's actually used does seem worth while.)
+ newUniqueSupply `thenM` \ us ->
+ returnM (case maybe_wkr_id of
+ Nothing -> info
+ Just wkr_id -> info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
+ `setWorkerInfo` HasWorker wkr_id arity)
- Nothing -> pprTrace "tcWorkerInfo failed:"
- (ppr worker_name) info
- in
- returnTc info'
where
+ doc = text "worker for" <+> ppr wkr_name
+
+ mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
+
-- We are relying here on strictness info always appearing
-- before worker info, fingers crossed ....
- strict_sig = case newStrictnessInfo info of
- Just sig -> sig
- Nothing -> pprPanic "Worker info but no strictness for" (ppr worker_name)
+ strict_sig = case newStrictnessInfo info of
+ Just sig -> sig
+ Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr_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 unf_env name in_scope_vars expr
- = tcDelay unf_env doc Nothing $
- tcCoreExpr expr `thenTc` \ core_expr' ->
+tcPragExpr :: Name -> [Id] -> UfExpr Name -> TcM (Maybe CoreExpr)
+tcPragExpr name in_scope_vars expr
+ = forkM doc $
+ tcCoreExpr expr `thenM` \ core_expr' ->
-- 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 (Just core_expr') -- ignore warnings
- (Just fail_msg,_) -> failWithTc ((doc <+> text "failed Lint") $$ fail_msg)
+ ifOptM Opt_DoCoreLinting (
+ getSrcLocM `thenM` \ src_loc ->
+ case lintUnfolding src_loc in_scope_vars core_expr' of
+ Nothing -> returnM ()
+ Just fail_msg -> failWithTc ((doc <+> text "Failed Lint") $$ fail_msg)
+ ) `thenM_`
+
+ returnM core_expr'
where
doc = text "unfolding of" <+> ppr name
-
-tcDelay :: RecTcEnv -> SDoc -> a -> TcM a -> NF_TcM a
-tcDelay unf_env doc bad_ans thing_inside
- = forkNF_Tc (
- recoverNF_Tc bad_value (
- tcSetEnv unf_env thing_inside
- ))
- where
- -- 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))
- bad_ans)
\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]
+ -- 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.
+tcVar name = tcLookupGlobalId name
\end{code}
UfCore expressions.
tcCoreExpr :: UfExpr Name -> TcM CoreExpr
tcCoreExpr (UfType ty)
- = tcIfaceType ty `thenTc` \ ty' ->
+ = tcIfaceType ty `thenM` \ ty' ->
-- It might not be of kind type
- returnTc (Type ty')
+ returnM (Type ty')
tcCoreExpr (UfVar name)
- = tcVar name `thenTc` \ id ->
- returnTc (Var id)
+ = tcVar name `thenM` \ id ->
+ returnM (Var id)
tcCoreExpr (UfLit lit)
- = returnTc (Lit lit)
+ = returnM (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'))
+ = tcIfaceType ty `thenM` \ ty' ->
+ returnM (Lit (MachLitLit lit ty'))
tcCoreExpr (UfFCall cc ty)
- = tcIfaceType ty `thenTc` \ ty' ->
- tcGetUnique `thenNF_Tc` \ u ->
- returnTc (Var (mkFCallId u cc ty'))
+ = tcIfaceType ty `thenM` \ ty' ->
+ newUnique `thenM` \ u ->
+ returnM (Var (mkFCallId u cc ty'))
-tcCoreExpr (UfTuple (HsTupCon _ boxity arity) args)
- = mapTc tcCoreExpr args `thenTc` \ args' ->
+tcCoreExpr (UfTuple (HsTupCon boxity arity) args)
+ = mappM tcCoreExpr args `thenM` \ args' ->
let
-- Put the missing type arguments back in
con_args = map (Type . exprType) args' ++ args'
in
- returnTc (mkApps (Var con_id) con_args)
+ returnM (mkApps (Var con_id) con_args)
where
- con_id = dataConId (tupleCon boxity arity)
+ con_id = dataConWorkId (tupleCon boxity arity)
tcCoreExpr (UfLam bndr body)
= tcCoreLamBndr bndr $ \ bndr' ->
- tcCoreExpr body `thenTc` \ body' ->
- returnTc (Lam bndr' body')
+ tcCoreExpr body `thenM` \ body' ->
+ returnM (Lam bndr' body')
tcCoreExpr (UfApp fun arg)
- = tcCoreExpr fun `thenTc` \ fun' ->
- tcCoreExpr arg `thenTc` \ arg' ->
- returnTc (App fun' arg')
+ = tcCoreExpr fun `thenM` \ fun' ->
+ tcCoreExpr arg `thenM` \ arg' ->
+ returnM (App fun' arg')
tcCoreExpr (UfCase scrut case_bndr alts)
- = tcCoreExpr scrut `thenTc` \ scrut' ->
+ = tcCoreExpr scrut `thenM` \ 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')
+ mappM (tcCoreAlt scrut_ty) alts `thenM` \ alts' ->
+ returnM (Case scrut' case_bndr' alts')
tcCoreExpr (UfLet (UfNonRec bndr rhs) body)
- = tcCoreExpr rhs `thenTc` \ rhs' ->
+ = tcCoreExpr rhs `thenM` \ rhs' ->
tcCoreValBndr bndr $ \ bndr' ->
- tcCoreExpr body `thenTc` \ body' ->
- returnTc (Let (NonRec bndr' rhs') body')
+ tcCoreExpr body `thenM` \ body' ->
+ returnM (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')
+ mappM tcCoreExpr rhss `thenM` \ rhss' ->
+ tcCoreExpr body `thenM` \ body' ->
+ returnM (Let (Rec (bndrs' `zip` rhss')) body')
where
(bndrs, rhss) = unzip pairs
tcCoreExpr (UfNote note expr)
- = tcCoreExpr expr `thenTc` \ expr' ->
+ = tcCoreExpr expr `thenM` \ expr' ->
case note of
- UfCoerce to_ty -> tcIfaceType to_ty `thenTc` \ to_ty' ->
- returnTc (Note (Coerce to_ty'
+ UfCoerce to_ty -> tcIfaceType to_ty `thenM` \ to_ty' ->
+ returnM (Note (Coerce to_ty'
(exprType expr')) expr')
- UfInlineCall -> returnTc (Note InlineCall expr')
- UfInlineMe -> returnTc (Note InlineMe expr')
- UfSCC cc -> returnTc (Note (SCC cc) expr')
+ UfInlineCall -> returnM (Note InlineCall expr')
+ UfInlineMe -> returnM (Note InlineMe expr')
+ UfSCC cc -> returnM (Note (SCC cc) expr')
\end{code}
\begin{code}
tcCoreLamBndr (UfValBinder name ty) thing_inside
- = tcIfaceType ty `thenTc` \ ty' ->
+ = tcIfaceType ty `thenM` \ ty' ->
let
id = mkLocalId name ty'
in
thing_inside (b':bs')
tcCoreValBndr (UfValBinder name ty) thing_inside
- = tcIfaceType ty `thenTc` \ ty' ->
+ = tcIfaceType ty `thenM` \ ty' ->
let
id = mkLocalId name ty'
in
thing_inside id
tcCoreValBndrs bndrs thing_inside -- Expect them all to be ValBinders
- = mapTc tcIfaceType tys `thenTc` \ tys' ->
+ = mappM tcIfaceType tys `thenM` \ tys' ->
let
ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys'
in
\begin{code}
tcCoreAlt scrut_ty (UfDefault, names, rhs)
= ASSERT( null names )
- tcCoreExpr rhs `thenTc` \ rhs' ->
- returnTc (DEFAULT, [], rhs')
+ tcCoreExpr rhs `thenM` \ rhs' ->
+ returnM (DEFAULT, [], rhs')
tcCoreAlt scrut_ty (UfLitAlt lit, names, rhs)
= ASSERT( null names )
- tcCoreExpr rhs `thenTc` \ rhs' ->
- returnTc (LitAlt lit, [], rhs')
+ tcCoreExpr rhs `thenM` \ rhs' ->
+ returnM (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')
+ tcCoreExpr rhs `thenM` \ rhs' ->
+ tcIfaceType ty `thenM` \ ty' ->
+ returnM (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 ->
+ = tcConAlt con `thenM` \ con ->
let
- (main_tyvars, _, ex_tyvars, _, _, _) = dataConSig con
-
- (tycon, inst_tys) = splitTyConApp scrut_ty -- NB: not tcSplitTyConApp
+ ex_tyvars = dataConExistentialTyVars 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 = dropList ex_tyvars names
+ main_tyvars = tyConTyVars tycon
+ 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 = dropList ex_tyvars names
arg_ids
#ifdef DEBUG
| not (equalLength id_names arg_tys)
ASSERT( con `elem` tyConDataCons tycon && equalLength inst_tys main_tyvars )
tcExtendTyVarEnv ex_tyvars' $
tcExtendGlobalValEnv arg_ids $
- tcCoreExpr rhs `thenTc` \ rhs' ->
- returnTc (DataAlt con, ex_tyvars' ++ arg_ids, rhs')
+ tcCoreExpr rhs `thenM` \ rhs' ->
+ returnM (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))
+tcConAlt (UfTupleAlt (HsTupCon boxity arity))
+ = returnM (tupleCon boxity arity)
+
+tcConAlt (UfDataAlt con_name) -- When reading interface files
+ -- the con_name will be the real name of
+ -- the data con
+ = tcLookupDataCon con_name
\end{code}
+%************************************************************************
+%* *
+\subsection{Core decls}
+%* *
+%************************************************************************
+
+
+\begin{code}
+tcCoreBinds :: [RenamedCoreDecl] -> TcM [TypecheckedCoreBind]
+-- We don't assume the bindings are in dependency order
+-- So first build the environment, then check the RHSs
+tcCoreBinds ls = mappM tcCoreBinder ls `thenM` \ bndrs ->
+ tcExtendGlobalValEnv bndrs $
+ mappM (tcCoreBind bndrs) ls
+
+tcCoreBinder (CoreDecl nm ty _ _)
+ = kcHsSigType ty `thenM_`
+ tcIfaceType ty `thenM` \ ty' ->
+ returnM (mkLocalId nm ty')
+
+tcCoreBind bndrs (CoreDecl nm _ rhs loc)
+ = tcVar nm `thenM` \ id ->
+ tcCoreExpr rhs `thenM` \ rhs' ->
+ let
+ mb_err = lintUnfolding loc bndrs rhs'
+ in
+ (case mb_err of
+ Just err -> addErr err
+ Nothing -> returnM ()) `thenM_`
+
+ returnM (id, rhs')
+\end{code}
+
+
\begin{code}
ifaceSigCtxt sig_name
= hsep [ptext SLIT("In an interface-file signature for"), ppr sig_name]