%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1995
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
%
\section[TcBinds]{TcBinds}
\begin{code}
#include "HsVersions.h"
-module TcBinds (
- tcTopBindsAndThen, tcLocalBindsAndThen,
- tcSigs, doSpecPragma
- ) where
-
---IMPORT_Trace -- ToDo:rm (debugging)
-
-import TcMonad -- typechecking monad machinery
-import TcMonadFns ( newLocalsWithOpenTyVarTys,
- newLocalsWithPolyTyVarTys,
- newSpecPragmaId, newSpecId,
- applyTcSubstAndCollectTyVars
- )
-import AbsSyn -- the stuff being typechecked
-
-import AbsUniType ( isTyVarTy, isGroundTy, isUnboxedDataType,
- isGroundOrTyVarTy, extractTyVarsFromTy,
- UniType
- )
-import BackSubst ( applyTcSubstToBinds )
-import E
-import Errors ( topLevelUnboxedDeclErr, specGroundnessErr,
- specCtxtGroundnessErr, Error(..), UnifyErrContext(..)
- )
-import GenSpecEtc ( checkSigTyVars, genBinds, SignatureInfo(..) )
-import Id ( getIdUniType, mkInstId )
-import IdInfo ( SpecInfo(..) )
-import Inst
-import LIE ( nullLIE, mkLIE, plusLIE, LIE )
-import Maybes ( assocMaybe, catMaybes, Maybe(..) )
-import Spec ( specTy )
-import TVE ( nullTVE, TVE(..), UniqFM )
-import TcMonoBnds ( tcMonoBinds )
-import TcPolyType ( tcPolyType )
+module TcBinds ( tcBindsAndThen, tcPragmaSigs ) where
+
+import Ubiq
+
+import HsSyn ( HsBinds(..), Bind(..), Sig(..), MonoBinds(..),
+ HsExpr, Match, PolyType, InPat, OutPat,
+ GRHSsAndBinds, ArithSeqInfo, HsLit, Fake,
+ collectBinders )
+import RnHsSyn ( RenamedHsBinds(..), RenamedBind(..), RenamedSig(..),
+ RenamedMonoBinds(..) )
+import TcHsSyn ( TcHsBinds(..), TcBind(..), TcMonoBinds(..),
+ TcIdOcc(..), TcIdBndr(..) )
+
+import TcMonad
+import GenSpecEtc ( checkSigTyVars, genBinds, TcSigInfo(..) )
+import Inst ( Inst, LIE(..), emptyLIE, plusLIE, InstOrigin(..) )
+import TcEnv ( tcExtendLocalValEnv, tcLookupLocalValueOK, newMonoIds )
+import TcLoop ( tcGRHSsAndBinds )
+import TcMatches ( tcMatchesFun )
+import TcMonoType ( tcPolyType )
+import TcPat ( tcPat )
import TcSimplify ( bindInstsOfLocalFuns )
+import TcType ( newTcTyVar, tcInstType )
import Unify ( unifyTauTy )
-import UniqFM ( emptyUFM ) -- profiling, pragmas only
-import Util
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Type-checking top-level bindings}
-%* *
-%************************************************************************
-
-@tcBindsAndThen@ takes a boolean which indicates whether the binding
-group is at top level or not. The difference from inner bindings is
-that
-\begin{enumerate}
-\item
-we zero the substitution before each group
-\item
-we back-substitute after each group.
-\end{enumerate}
-We still return an LIE, but it is sure to contain nothing but constant
-dictionaries, which we resolve at the module level.
-
-@tcTopBinds@ returns an LVE, not, as you might expect, a GVE. Why?
-Because the monomorphism restriction means that is might return some
-monomorphic things, with free type variables. Hence it must be an LVE.
-The LIE returned by @tcTopBinds@ may constrain some type variables,
-but they are guaranteed to be a subset of those free in the
-corresponding returned LVE.
+import Kind ( mkBoxedTypeKind, mkTypeKind )
+import Id ( GenId, idType, mkUserId )
+import IdInfo ( noIdInfo )
+import Name ( Name ) -- instances
+import Maybes ( assocMaybe, catMaybes, Maybe(..) )
+import Outputable ( pprNonOp )
+import PragmaInfo ( PragmaInfo(..) )
+import Pretty
+import Type ( mkTyVarTy, isTyVarTy, mkSigmaTy, splitSigmaTy,
+ splitRhoTy, mkForAllTy, splitForAllTy )
+import Util ( panic )
+\end{code}
%************************************************************************
%* *
%* *
%************************************************************************
-@tcBindsAndThen@ typechecks a @Binds@. The "and then" part is because
+@tcBindsAndThen@ typechecks a @HsBinds@. The "and then" part is because
it needs to know something about the {\em usage} of the things bound,
so that it can create specialisations of them. So @tcBindsAndThen@
takes a function which, given an extended environment, E, typechecks
checked the type of its LHS is unified with that of its RHS; and
type-checking the LHS of course requires that the binder is in scope.
+At the top-level the LIE is sure to contain nothing but constant
+dictionaries, which we resolve at the module level.
+
\begin{code}
-tcBindsAndThen
- :: Bool
- -> E
- -> (TypecheckedBinds -> thing -> thing) -- Combinator
- -> RenamedBinds
- -> (E -> TcM (thing, LIE, thing_ty))
- -> TcM (thing, LIE, thing_ty)
-
-tcBindsAndThen top_level e combiner EmptyBinds do_next
- = do_next e `thenTc` \ (thing, lie, thing_ty) ->
+tcBindsAndThen
+ :: (TcHsBinds s -> thing -> thing) -- Combinator
+ -> RenamedHsBinds
+ -> TcM s (thing, LIE s, thing_ty)
+ -> TcM s (thing, LIE s, thing_ty)
+
+tcBindsAndThen combiner EmptyBinds do_next
+ = do_next `thenTc` \ (thing, lie, thing_ty) ->
returnTc (combiner EmptyBinds thing, lie, thing_ty)
-tcBindsAndThen top_level e combiner (SingleBind bind) do_next
- = tcBindAndThen top_level e combiner bind [] do_next
+tcBindsAndThen combiner (SingleBind bind) do_next
+ = tcBindAndThen combiner bind [] do_next
-tcBindsAndThen top_level e combiner (BindWith bind sigs) do_next
- = tcBindAndThen top_level e combiner bind sigs do_next
-
-tcBindsAndThen top_level e combiner (ThenBinds binds1 binds2) do_next
- = tcBindsAndThen top_level e combiner binds1 new_after
- where
- -- new_after :: E -> TcM (thing, LIE, thing_ty)
- -- Can't write this signature, cos it's monomorphic in thing and
- -- thing_ty.
- new_after e = tcBindsAndThen top_level e combiner binds2 do_next
-\end{code}
+tcBindsAndThen combiner (BindWith bind sigs) do_next
+ = tcBindAndThen combiner bind sigs do_next
-Simple wrappers for export:
-\begin{code}
-tcTopBindsAndThen
- :: E
- -> (TypecheckedBinds -> thing -> thing) -- Combinator
- -> RenamedBinds
- -> (E -> TcM (thing, LIE, anything))
- -> TcM (thing, LIE, anything)
-
-tcTopBindsAndThen e combiner binds do_next
- = tcBindsAndThen True e combiner binds do_next
-
-tcLocalBindsAndThen
- :: E
- -> (TypecheckedBinds -> thing -> thing) -- Combinator
- -> RenamedBinds
- -> (E -> TcM (thing, LIE, thing_ty))
- -> TcM (thing, LIE, thing_ty)
-
-tcLocalBindsAndThen e combiner binds do_next
- = tcBindsAndThen False e combiner binds do_next
+tcBindsAndThen combiner (ThenBinds binds1 binds2) do_next
+ = tcBindsAndThen combiner binds1 (tcBindsAndThen combiner binds2 do_next)
\end{code}
An aside. The original version of @tcBindsAndThen@ which lacks a
examples of this, which is why I thought it worth preserving! [SLPJ]
\begin{pseudocode}
-tcBindsAndThen
- :: Bool -> E -> RenamedBinds
- -> (E -> TcM (thing, LIE, thing_ty))
- -> TcM ((TypecheckedBinds, thing), LIE, thing_ty)
+tcBindsAndThen
+ :: RenamedHsBinds
+ -> TcM s (thing, LIE s, thing_ty))
+ -> TcM s ((TcHsBinds s, thing), LIE s, thing_ty)
-tcBindsAndThen top_level e EmptyBinds do_next
- = do_next e `thenTc` \ (thing, lie, thing_ty) ->
+tcBindsAndThen EmptyBinds do_next
+ = do_next `thenTc` \ (thing, lie, thing_ty) ->
returnTc ((EmptyBinds, thing), lie, thing_ty)
-tcBindsAndThen top_level e (SingleBind bind) do_next
- = tcBindAndThen top_level e bind [] do_next
+tcBindsAndThen (SingleBind bind) do_next
+ = tcBindAndThen bind [] do_next
-tcBindsAndThen top_level e (BindWith bind sigs) do_next
- = tcBindAndThen top_level e bind sigs do_next
+tcBindsAndThen (BindWith bind sigs) do_next
+ = tcBindAndThen bind sigs do_next
-tcBindsAndThen top_level e (ThenBinds binds1 binds2) do_next
- = tcBindsAndThen top_level e binds1 new_after
+tcBindsAndThen (ThenBinds binds1 binds2) do_next
+ = tcBindsAndThen binds1 (tcBindsAndThen binds2 do_next)
`thenTc` \ ((binds1', (binds2', thing')), lie1, thing_ty) ->
returnTc ((binds1' `ThenBinds` binds2', thing'), lie1, thing_ty)
-
- where
- -- new_after :: E -> TcM ((TypecheckedBinds, thing), LIE, thing_ty)
- -- Can't write this signature, cos it's monomorphic in thing and thing_ty
- new_after e = tcBindsAndThen top_level e binds2 do_next
\end{pseudocode}
%************************************************************************
\begin{code}
tcBindAndThen
- :: Bool -- At top level
- -> E
- -> (TypecheckedBinds -> thing -> thing) -- Combinator
+ :: (TcHsBinds s -> thing -> thing) -- Combinator
-> RenamedBind -- The Bind to typecheck
-> [RenamedSig] -- ...and its signatures
- -> (E -> TcM (thing, LIE, thing_ty)) -- Thing to type check in
+ -> TcM s (thing, LIE s, thing_ty) -- Thing to type check in
-- augmented envt
- -> TcM (thing, LIE, thing_ty) -- Results, incl the
+ -> TcM s (thing, LIE s, thing_ty) -- Results, incl the
-tcBindAndThen top_level e combiner bind sigs do_next
- = -- Deal with the bind
- tcBind top_level e bind sigs `thenTc` \ (poly_binds, poly_lie, poly_lve) ->
+tcBindAndThen combiner bind sigs do_next
+ = fixTc (\ ~(prag_info_fn, _) ->
+ -- This is the usual prag_info fix; the PragmaInfo field of an Id
+ -- is not inspected till ages later in the compiler, so there
+ -- should be no black-hole problems here.
+
+ tcBindAndSigs binder_names bind
+ sigs prag_info_fn `thenTc` \ (poly_binds, poly_lie, poly_ids) ->
+
+ -- Extend the environment to bind the new polymorphic Ids
+ tcExtendLocalValEnv binder_names poly_ids $
+
+ -- Build bindings and IdInfos corresponding to user pragmas
+ tcPragmaSigs sigs `thenTc` \ (prag_info_fn, prag_binds, prag_lie) ->
-- Now do whatever happens next, in the augmented envt
- do_next (growE_LVE e poly_lve) `thenTc` \ (thing, thing_lie, thing_ty) ->
+ do_next `thenTc` \ (thing, thing_lie, thing_ty) ->
+
+ -- Create specialisations of functions bound here
+ bindInstsOfLocalFuns (prag_lie `plusLIE` thing_lie)
+ poly_ids `thenTc` \ (lie2, inst_mbinds) ->
+
+ -- All done
let
- bound_ids = map snd poly_lve
+ final_lie = lie2 `plusLIE` poly_lie
+ final_binds = poly_binds `ThenBinds`
+ SingleBind (NonRecBind inst_mbinds) `ThenBinds`
+ prag_binds
in
- -- Create specialisations
- specialiseBinds bound_ids thing_lie poly_binds poly_lie
- `thenNF_Tc` \ (final_binds, final_lie) ->
- -- All done
- returnTc (combiner final_binds thing, final_lie, thing_ty)
+ returnTc (prag_info_fn, (combiner final_binds thing, final_lie, thing_ty))
+ ) `thenTc` \ (_, result) ->
+ returnTc result
+ where
+ binder_names = collectBinders bind
+
+
+tcBindAndSigs binder_names bind sigs prag_info_fn
+ = recoverTc (
+ -- If typechecking the binds fails, then return with each
+ -- binder given type (forall a.a), to minimise subsequent
+ -- error messages
+ newTcTyVar Nothing mkBoxedTypeKind `thenNF_Tc` \ alpha_tv ->
+ let
+ forall_a_a = mkForAllTy alpha_tv (mkTyVarTy alpha_tv)
+ poly_ids = [ mkUserId name forall_a_a (prag_info_fn name)
+ | name <- binder_names]
+ in
+ returnTc (EmptyBinds, emptyLIE, poly_ids)
+ ) $
+
+ -- Create a new identifier for each binder, with each being given
+ -- a type-variable type.
+ newMonoIds binder_names kind (\ mono_ids ->
+ tcTySigs sigs `thenTc` \ sig_info ->
+ tc_bind bind `thenTc` \ (bind', lie) ->
+ returnTc (mono_ids, bind', lie, sig_info)
+ )
+ `thenTc` \ (mono_ids, bind', lie, sig_info) ->
+
+ -- Notice that genBinds gets the old (non-extended) environment
+ genBinds binder_names mono_ids bind' lie sig_info prag_info_fn
+ where
+ kind = case bind of
+ NonRecBind _ -> mkBoxedTypeKind -- Recursive, so no unboxed types
+ RecBind _ -> mkTypeKind -- Non-recursive, so we permit unboxed types
\end{code}
\begin{code}
-tcBind :: Bool -> E
- -> RenamedBind -> [RenamedSig]
- -> TcM (TypecheckedBinds, LIE, LVE) -- LIE is a fixed point of substitution
+tc_bind :: RenamedBind -> TcM s (TcBind s, LIE s)
-tcBind False e bind sigs -- Not top level
- = tcBind_help False e bind sigs
+tc_bind (NonRecBind mono_binds)
+ = tcMonoBinds mono_binds `thenTc` \ (mono_binds2, lie) ->
+ returnTc (NonRecBind mono_binds2, lie)
-tcBind True e bind sigs -- Top level!
- = pruneSubstTc (tvOfE e) (
+tc_bind (RecBind mono_binds)
+ = tcMonoBinds mono_binds `thenTc` \ (mono_binds2, lie) ->
+ returnTc (RecBind mono_binds2, lie)
+\end{code}
- -- DO THE WORK
- tcBind_help True e bind sigs `thenTc` \ (new_binds, lie, lve) ->
+\begin{code}
+tcMonoBinds :: RenamedMonoBinds -> TcM s (TcMonoBinds s, LIE s)
-{- Top-level unboxed values are now allowed
- They will be lifted by the Desugarer (see CoreLift.lhs)
+tcMonoBinds EmptyMonoBinds = returnTc (EmptyMonoBinds, emptyLIE)
- -- CHECK FOR PRIMITIVE TOP-LEVEL BINDS
- listTc [ checkTc (isUnboxedDataType (getIdUniType id))
- (topLevelUnboxedDeclErr id (getSrcLoc id))
- | (_,id) <- lve ] `thenTc_`
--}
+tcMonoBinds (AndMonoBinds mb1 mb2)
+ = tcMonoBinds mb1 `thenTc` \ (mb1a, lie1) ->
+ tcMonoBinds mb2 `thenTc` \ (mb2a, lie2) ->
+ returnTc (AndMonoBinds mb1a mb2a, lie1 `plusLIE` lie2)
- -- Back-substitute over the binds, since we are about to discard
- -- a good chunk of the substitution.
- applyTcSubstToBinds new_binds `thenNF_Tc` \ final_binds ->
+tcMonoBinds bind@(PatMonoBind pat grhss_and_binds locn)
+ = tcAddSrcLoc locn $
- -- The lie is already a fixed point of the substitution; it just turns out
- -- that almost always this happens automatically, and so we made it part of
- -- the specification of genBinds.
- returnTc (final_binds, lie, lve)
- )
+ -- LEFT HAND SIDE
+ tcPat pat `thenTc` \ (pat2, lie_pat, pat_ty) ->
+
+ -- BINDINGS AND GRHSS
+ tcGRHSsAndBinds grhss_and_binds `thenTc` \ (grhss_and_binds2, lie, grhss_ty) ->
+
+ -- Unify the two sides
+ tcAddErrCtxt (patMonoBindsCtxt bind) $
+ unifyTauTy pat_ty grhss_ty `thenTc_`
+
+ -- RETURN
+ returnTc (PatMonoBind pat2 grhss_and_binds2 locn,
+ plusLIE lie_pat lie)
+
+tcMonoBinds (FunMonoBind name matches locn)
+ = tcAddSrcLoc locn $
+ tcLookupLocalValueOK "tcMonoBinds" name `thenNF_Tc` \ id ->
+ tcMatchesFun name (idType id) matches `thenTc` \ (matches', lie) ->
+ returnTc (FunMonoBind (TcId id) matches' locn, lie)
\end{code}
+%************************************************************************
+%* *
+\subsection{Signatures}
+%* *
+%************************************************************************
+
+@tcSigs@ checks the signatures for validity, and returns a list of
+{\em freshly-instantiated} signatures. That is, the types are already
+split up, and have fresh type variables installed. All non-type-signature
+"RenamedSigs" are ignored.
+
\begin{code}
-tcBind_help top_level e bind sigs
- = -- Create an LVE binding each identifier to an appropriate type variable
- new_locals binders `thenNF_Tc` \ bound_ids ->
- let lve = binders `zip` bound_ids in
-
- -- Now deal with type signatures, if any
- tcSigs e lve sigs `thenTc` \ sig_info ->
-
- -- Check the bindings: this is the point at which we can use
- -- error recovery. If checking the bind fails we just
- -- return the empty bindings. The variables will still be in
- -- scope, but bound to completely free type variables, which
- -- is just what we want to minimise subsequent error messages.
- recoverTc (NonRecBind EmptyMonoBinds, nullLIE)
- (tc_bind (growE_LVE e lve) bind) `thenNF_Tc` \ (bind', lie) ->
-
- -- Notice that genBinds gets the old (non-extended) environment
- genBinds top_level e bind' lie lve sig_info `thenTc` \ (binds', lie, lve) ->
-
- -- Add bindings corresponding to SPECIALIZE pragmas in the code
- mapAndUnzipTc (doSpecPragma e (assoc "doSpecPragma" lve))
- (get_spec_pragmas sig_info)
- `thenTc` \ (spec_binds_s, spec_lie_s) ->
-
- returnTc (binds' `ThenBinds` (SingleBind (NonRecBind (
- foldr AndMonoBinds EmptyMonoBinds spec_binds_s))),
- lie `plusLIE` (foldr plusLIE nullLIE spec_lie_s),
- lve)
- where
- binders = collectBinders bind
+tcTySigs :: [RenamedSig] -> TcM s [TcSigInfo s]
+
+tcTySigs (Sig v ty _ src_loc : other_sigs)
+ = tcAddSrcLoc src_loc (
+ tcPolyType ty `thenTc` \ sigma_ty ->
+ tcInstType [] sigma_ty `thenNF_Tc` \ tc_sigma_ty ->
+ let
+ (tyvars, theta, tau_ty) = splitSigmaTy tc_sigma_ty
+ in
+ tcLookupLocalValueOK "tcSig1" v `thenNF_Tc` \ val ->
+ unifyTauTy (idType val) tau_ty `thenTc_`
+ returnTc (TySigInfo val tyvars theta tau_ty src_loc)
+ ) `thenTc` \ sig_info1 ->
+
+ tcTySigs other_sigs `thenTc` \ sig_infos ->
+ returnTc (sig_info1 : sig_infos)
+
+tcTySigs (other : sigs) = tcTySigs sigs
+tcTySigs [] = returnTc []
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{SPECIALIZE pragmas}
+%* *
+%************************************************************************
+
+
+@tcPragmaSigs@ munches up the "signatures" that arise through *user*
+pragmas. It is convenient for them to appear in the @[RenamedSig]@
+part of a binding because then the same machinery can be used for
+moving them into place as is done for type signatures.
+
+\begin{code}
+tcPragmaSigs :: [RenamedSig] -- The pragma signatures
+ -> TcM s (Name -> PragmaInfo, -- Maps name to the appropriate PragmaInfo
+ TcHsBinds s,
+ LIE s)
+
+tcPragmaSigs sigs = returnTc ( \name -> NoPragmaInfo, EmptyBinds, emptyLIE )
- new_locals binders
- = case bind of
- NonRecBind _ -> -- Recursive, so no unboxed types
- newLocalsWithOpenTyVarTys binders
+{-
+tcPragmaSigs sigs
+ = mapAndUnzip3Tc tcPragmaSig sigs `thenTc` \ (names_w_id_infos, binds, lies) ->
+ let
+ name_to_info name = foldr ($) noIdInfo
+ [info_fn | (n,info_fn) <- names_w_id_infos, n==name]
+ in
+ returnTc (name_to_info,
+ foldr ThenBinds EmptyBinds binds,
+ foldr plusLIE emptyLIE lies)
+\end{code}
- RecBind _ -> -- Non-recursive, so we permit unboxed types
- newLocalsWithPolyTyVarTys binders
+Here are the easy cases for tcPragmaSigs
- get_spec_pragmas sig_info
- = catMaybes (map get_pragma_maybe sig_info)
- where
- get_pragma_maybe s@(ValSpecInfo _ _ _ _) = Just s
- get_pragma_maybe _ = Nothing
+\begin{code}
+tcPragmaSig (DeforestSig name loc)
+ = returnTc ((name, addInfo DoDeforest),EmptyBinds,emptyLIE)
+tcPragmaSig (InlineSig name loc)
+ = returnTc ((name, addInfo_UF (iWantToBeINLINEd UnfoldAlways)), EmptyBinds, emptyLIE)
+tcPragmaSig (MagicUnfoldingSig name string loc)
+ = returnTc ((name, addInfo_UF (mkMagicUnfolding string)), EmptyBinds, emptyLIE)
\end{code}
+The interesting case is for SPECIALISE pragmas. There are two forms.
+Here's the first form:
\begin{verbatim}
f :: Ord a => [a] -> b -> b
{-# SPECIALIZE f :: [Int] -> b -> b #-}
\end{verbatim}
-We generate:
+
+For this we generate:
\begin{verbatim}
- f@Int = /\ b -> let d1 = ...
- in f Int b d1
+ f* = /\ b -> let d1 = ...
+ in f Int b d1
+\end{verbatim}
+where f* is a SpecPragmaId. The **sole** purpose of SpecPragmaIds is to
+retain a right-hand-side that the simplifier will otherwise discard as
+dead code... the simplifier has a flag that tells it not to discard
+SpecPragmaId bindings.
- h :: Ord a => [a] -> b -> b
- {-# SPECIALIZE h :: [Int] -> b -> b #-}
+In this case the f* retains a call-instance of the overloaded
+function, f, (including appropriate dictionaries) so that the
+specialiser will subsequently discover that there's a call of @f@ at
+Int, and will create a specialisation for @f@. After that, the
+binding for @f*@ can be discarded.
+
+The second form is this:
+\begin{verbatim}
+ f :: Ord a => [a] -> b -> b
+ {-# SPECIALIZE f :: [Int] -> b -> b = g #-}
+\end{verbatim}
- spec_h = /\b -> h [Int] b dListOfInt
- ^^^^^^^^^^^^^^^^^^^^ This bit created by specId
+Here @g@ is specified as a function that implements the specialised
+version of @f@. Suppose that g has type (a->b->b); that is, g's type
+is more general than that required. For this we generate
+\begin{verbatim}
+ f@Int = /\b -> g Int b
+ f* = f@Int
\end{verbatim}
+Here @f@@Int@ is a SpecId, the specialised version of @f@. It inherits
+f's export status etc. @f*@ is a SpecPragmaId, as before, which just serves
+to prevent @f@@Int@ from being discarded prematurely. After specialisation,
+if @f@@Int@ is going to be used at all it will be used explicitly, so the simplifier can
+discard the f* binding.
+
+Actually, there is really only point in giving a SPECIALISE pragma on exported things,
+and the simplifer won't discard SpecIds for exporte things anyway, so maybe this is
+a bit of overkill.
+
\begin{code}
-doSpecPragma :: E
- -> (Name -> Id)
- -> SignatureInfo
- -> TcM (TypecheckedMonoBinds, LIE)
-
-doSpecPragma e name_to_id (ValSpecInfo name spec_ty using src_loc)
- = let
- main_id = name_to_id name -- Get the parent Id
-
- main_id_ty = getIdUniType main_id
- main_id_free_tyvars = extractTyVarsFromTy main_id_ty
- origin = ValSpecOrigin name src_loc
- err_ctxt = ValSpecSigCtxt name spec_ty src_loc
+tcPragmaSig (SpecSig name poly_ty maybe_spec_name src_loc)
+ = tcAddSrcLoc src_loc $
+ tcAddErrCtxt (valSpecSigCtxt name spec_ty) $
+
+ -- Get and instantiate its alleged specialised type
+ tcPolyType poly_ty `thenTc` \ sig_sigma ->
+ tcInstType [] (idType sig_sigma) `thenNF_Tc` \ sig_ty ->
+ let
+ (sig_tyvars, sig_theta, sig_tau) = splitSigmaTy sig_ty
+ origin = ValSpecOrigin name
in
- addSrcLocTc src_loc (
- specTy origin spec_ty `thenNF_Tc` \ (spec_tyvars, spec_dicts, spec_tau) ->
-- Check that the SPECIALIZE pragma had an empty context
- checkTc (not (null spec_dicts))
+ checkTc (null sig_theta)
(panic "SPECIALIZE non-empty context (ToDo: msg)") `thenTc_`
- -- Make an instance of this id
- specTy origin main_id_ty `thenNF_Tc` \ (main_tyvars, main_dicts, main_tau) ->
+ -- Get and instantiate the type of the id mentioned
+ tcLookupLocalValueOK "tcPragmaSig" name `thenNF_Tc` \ main_id ->
+ tcInstType [] (idType main_id) `thenNF_Tc` \ main_ty ->
+ let
+ (main_tyvars, main_rho) = splitForAllTy main_ty
+ (main_theta,main_tau) = splitRhoTy main_rho
+ main_arg_tys = map mkTyVarTy main_tyvars
+ in
-- Check that the specialised type is indeed an instance of
- -- the inferred type.
- -- The unification should leave all type vars which are
- -- currently free in the environment still free, and likewise
- -- the signature type vars.
- -- The only way type vars free in the envt could possibly be affected
- -- is if main_id_ty has free type variables. So we just extract them,
- -- and check that they are not constrained in any way by the unification.
- applyTcSubstAndCollectTyVars main_id_free_tyvars `thenNF_Tc` \ free_tyvars' ->
- unifyTauTy spec_tau main_tau err_ctxt `thenTc_`
- checkSigTyVars [] (spec_tyvars ++ free_tyvars')
- spec_tau main_tau err_ctxt `thenTc_`
+ -- the type of the main function.
+ unifyTauTy sig_tau main_tau `thenTc_`
+ checkSigTyVars sig_tyvars sig_tau main_tau `thenTc_`
-- Check that the type variables of the polymorphic function are
-- either left polymorphic, or instantiate to ground type.
-- Also check that the overloaded type variables are instantiated to
-- ground type; or equivalently that all dictionaries have ground type
- applyTcSubstToTyVars main_tyvars `thenNF_Tc` \ main_arg_tys ->
- applyTcSubstToInsts main_dicts `thenNF_Tc` \ main_dicts' ->
-
- checkTc (not (all isGroundOrTyVarTy main_arg_tys))
- (specGroundnessErr err_ctxt main_arg_tys)
- `thenTc_`
+ mapTc zonkTcType main_arg_tys `thenNF_Tc` \ main_arg_tys' ->
+ zonkTcThetaType main_theta `thenNF_Tc` \ main_theta' ->
+ tcAddErrCtxt (specGroundnessCtxt main_arg_tys')
+ (checkTc (all isGroundOrTyVarTy main_arg_tys')) `thenTc_`
+ tcAddErrCtxt (specContextGroundnessCtxt main_theta')
+ (checkTc (and [isGroundTy ty | (_,ty) <- theta'])) `thenTc_`
- checkTc (not (and [isGroundTy ty | (_,ty) <- map getDictClassAndType main_dicts']))
- (specCtxtGroundnessErr err_ctxt main_dicts')
- `thenTc_`
+ -- Build the SpecPragmaId; it is the thing that makes sure we
+ -- don't prematurely dead-code-eliminate the binding we are really interested in.
+ newSpecPragmaId name sig_ty `thenNF_Tc` \ spec_pragma_id ->
-- Build a suitable binding; depending on whether we were given
-- a value (Maybe Name) to be used as the specialisation.
case using of
- Nothing ->
+ Nothing -> -- No implementation function specified
+
+ -- Make a Method inst for the occurrence of the overloaded function
+ newMethodWithGivenTy (OccurrenceOf name)
+ (TcId main_id) main_arg_tys main_rho `thenNF_Tc` \ (lie, meth_id) ->
- -- Make a specPragmaId to which to bind the new call-instance
- newSpecPragmaId name spec_ty Nothing
- `thenNF_Tc` \ pseudo_spec_id ->
let
- pseudo_bind = VarMonoBind pseudo_spec_id pseudo_rhs
- pseudo_rhs = mkTyLam spec_tyvars (mkDictApp (mkTyApp (Var main_id) main_arg_tys)
- (map mkInstId main_dicts'))
+ pseudo_bind = VarMonoBind spec_pragma_id pseudo_rhs
+ pseudo_rhs = mkHsTyLam sig_tyvars (HsVar (TcId meth_id))
in
- returnTc (pseudo_bind, mkLIE main_dicts')
+ returnTc (pseudo_bind, lie, \ info -> info)
- Just spec_name -> -- use spec_name as the specialisation value ...
- let
- spec_id = lookupE_Value e spec_name
- spec_id_ty = getIdUniType spec_id
+ Just spec_name -> -- Use spec_name as the specialisation value ...
- spec_id_free_tyvars = extractTyVarsFromTy spec_id_ty
- spec_id_ctxt = ValSpecSpecIdCtxt name spec_ty spec_name src_loc
+ -- Type check a simple occurrence of the specialised Id
+ tcId spec_name `thenTc` \ (spec_body, spec_lie, spec_tau) ->
- spec_tys = map maybe_ty main_arg_tys
- maybe_ty ty | isTyVarTy ty = Nothing
- | otherwise = Just ty
- in
- -- Make an instance of the spec_id
- specTy origin spec_id_ty `thenNF_Tc` \ (spec_id_tyvars, spec_id_dicts, spec_id_tau) ->
-
- -- Check that the specialised type is indeed an instance of
- -- the type inferred for spec_id
- -- The unification should leave all type vars which are
- -- currently free in the environment still free, and likewise
- -- the signature type vars.
- -- The only way type vars free in the envt could possibly be affected
- -- is if spec_id_ty has free type variables. So we just extract them,
- -- and check that they are not constrained in any way by the unification.
- applyTcSubstAndCollectTyVars spec_id_free_tyvars `thenNF_Tc` \ spec_id_free_tyvars' ->
- unifyTauTy spec_tau spec_id_tau spec_id_ctxt `thenTc_`
- checkSigTyVars [] (spec_tyvars ++ spec_id_free_tyvars')
- spec_tau spec_id_tau spec_id_ctxt `thenTc_`
-
- -- Check that the type variables of the explicit spec_id are
- -- either left polymorphic, or instantiate to ground type.
- -- Also check that the overloaded type variables are instantiated to
- -- ground type; or equivalently that all dictionaries have ground type
- applyTcSubstToTyVars spec_id_tyvars `thenNF_Tc` \ spec_id_arg_tys ->
- applyTcSubstToInsts spec_id_dicts `thenNF_Tc` \ spec_id_dicts' ->
-
- checkTc (not (all isGroundOrTyVarTy spec_id_arg_tys))
- (specGroundnessErr spec_id_ctxt spec_id_arg_tys)
- `thenTc_`
-
- checkTc (not (and [isGroundTy ty | (_,ty) <- map getDictClassAndType spec_id_dicts']))
- (specCtxtGroundnessErr spec_id_ctxt spec_id_dicts')
- `thenTc_`
+ -- Check that it has the correct type, and doesn't constrain the
+ -- signature variables at all
+ unifyTauTy sig_tau spec_tau `thenTc_`
+ checkSigTyVars sig_tyvars sig_tau spec_tau `thenTc_`
-- Make a local SpecId to bind to applied spec_id
- newSpecId main_id spec_tys spec_ty `thenNF_Tc` \ local_spec_id ->
-
- -- Make a specPragmaId id with a spec_info for local_spec_id
- -- This is bound to local_spec_id
- -- The SpecInfo will be extracted by the specialiser and
- -- used to create a call instance for main_id (which is
- -- extracted from the spec_id)
- -- NB: the pseudo_local_id must stay in the scope of main_id !!!
- let
- spec_info = SpecInfo spec_tys (length main_dicts') local_spec_id
- in
- newSpecPragmaId name spec_ty (Just spec_info) `thenNF_Tc` \ pseudo_spec_id ->
+ newSpecId main_id main_arg_tys sig_ty `thenNF_Tc` \ local_spec_id ->
+
let
- spec_bind = VarMonoBind local_spec_id spec_rhs
- spec_rhs = mkTyLam spec_tyvars (mkDictApp (mkTyApp (Var spec_id) spec_id_arg_tys)
- (map mkInstId spec_id_dicts'))
- pseudo_bind = VarMonoBind pseudo_spec_id (Var local_spec_id)
+ spec_rhs = mkHsTyLam sig_tyvars spec_body
+ spec_binds = VarMonoBind local_spec_id spec_rhs
+ `AndMonoBinds`
+ VarMonoBind spec_pragma_id (HsVar (TcId local_spec_id))
+ spec_info = SpecInfo spec_tys (length main_theta) local_spec_id
in
- returnTc (spec_bind `AndMonoBinds` pseudo_bind, mkLIE spec_id_dicts')
- )
+ returnTc ((name, addInfo spec_info), spec_binds, spec_lie)
+-}
\end{code}
-\begin{code}
-tc_bind :: E
- -> RenamedBind
- -> TcM (TypecheckedBind, LIE)
-
-tc_bind e (NonRecBind mono_binds)
- = tcMonoBinds e mono_binds `thenTc` \ (mono_binds2, lie) ->
- returnTc (NonRecBind mono_binds2, lie)
-
-tc_bind e (RecBind mono_binds)
- = tcMonoBinds e mono_binds `thenTc` \ (mono_binds2, lie) ->
- returnTc (RecBind mono_binds2, lie)
-\end{code}
+Error contexts and messages
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
-specialiseBinds
- :: [Id] -- Ids bound in this group
- -> LIE -- LIE of scope of these bindings
- -> TypecheckedBinds
- -> LIE
- -> NF_TcM (TypecheckedBinds, LIE)
-
-specialiseBinds bound_ids lie_of_scope poly_binds poly_lie
- = bindInstsOfLocalFuns lie_of_scope bound_ids
- `thenNF_Tc` \ (lie2, inst_mbinds) ->
-
- returnNF_Tc (poly_binds `ThenBinds` (SingleBind (NonRecBind inst_mbinds)),
- lie2 `plusLIE` poly_lie)
-\end{code}
-
-%************************************************************************
-%* *
-\subsection{Signatures}
-%* *
-%************************************************************************
-
-@tcSigs@ checks the signatures for validity, and returns a list of
-{\em freshly-instantiated} signatures. That is, the types are already
-split up, and have fresh type variables (not @TyVarTemplate@s)
-installed.
-
-\begin{code}
-tcSigs :: E -> LVE
- -> [RenamedSig]
- -> TcM [SignatureInfo]
-
-tcSigs e lve [] = returnTc []
-
-tcSigs e lve (s:ss)
- = tc_sig s `thenTc` \ sig_info1 ->
- tcSigs e lve ss `thenTc` \ sig_info2 ->
- returnTc (sig_info1 : sig_info2)
+patMonoBindsCtxt bind sty
+ = ppHang (ppPStr SLIT("In a pattern binding:")) 4 (ppr sty bind)
+
+--------------------------------------------
+specContextGroundnessCtxt -- err_ctxt dicts sty
+ = panic "specContextGroundnessCtxt"
+{-
+ = ppHang (
+ ppSep [ppBesides [ppStr "In the SPECIALIZE pragma for `", ppr sty name, ppStr "'"],
+ ppBesides [ppStr " specialised to the type `", ppr sty spec_ty, ppStr "'"],
+ pp_spec_id sty,
+ ppStr "... not all overloaded type variables were instantiated",
+ ppStr "to ground types:"])
+ 4 (ppAboves [ppCat [ppr sty c, ppr sty t]
+ | (c,t) <- map getDictClassAndType dicts])
where
- tc_sig (Sig v ty _ src_loc) -- no interesting pragmas on non-iface sigs
- = addSrcLocTc src_loc (
-
- babyTcMtoTcM
- (tcPolyType (getE_CE e) (getE_TCE e) nullTVE ty) `thenTc` \ sigma_ty ->
-
- let val = assoc "tcSigs" lve v in
- -- (The renamer/dependency-analyser should have ensured
- -- that there are only signatures for which there is a
- -- corresponding binding.)
-
- -- Instantiate the type, and unify with the type variable
- -- found in the Id.
- specTy SignatureOrigin sigma_ty `thenNF_Tc` \ (tyvars, dicts, tau_ty) ->
- unifyTauTy (getIdUniType val) tau_ty
- (panic "ToDo: unifyTauTy(tcSigs)") `thenTc_`
-
- returnTc (TySigInfo val tyvars dicts tau_ty src_loc)
- )
-
- tc_sig (SpecSig v ty using src_loc)
- = addSrcLocTc src_loc (
-
- babyTcMtoTcM
- (tcPolyType (getE_CE e) (getE_TCE e) nullTVE ty) `thenTc` \ sigma_ty ->
-
- returnTc (ValSpecInfo v sigma_ty using src_loc)
- )
+ (name, spec_ty, locn, pp_spec_id)
+ = case err_ctxt of
+ ValSpecSigCtxt n ty loc -> (n, ty, loc, \ x -> ppNil)
+ ValSpecSpecIdCtxt n ty spec loc ->
+ (n, ty, loc,
+ \ sty -> ppBesides [ppStr "... type of explicit id `", ppr sty spec, ppStr "'"])
+-}
- tc_sig (InlineSig v guide locn)
- = returnTc (ValInlineInfo v guide locn)
+-----------------------------------------------
+specGroundnessCtxt
+ = panic "specGroundnessCtxt"
- tc_sig (DeforestSig v locn)
- = returnTc (ValDeforestInfo v locn)
- tc_sig (MagicUnfoldingSig v str locn)
- = returnTc (ValMagicUnfoldingInfo v str locn)
+valSpecSigCtxt v ty sty
+ = ppHang (ppPStr SLIT("In a SPECIALIZE pragma for a value:"))
+ 4 (ppSep [ppBeside (pprNonOp sty v) (ppPStr SLIT(" ::")),
+ ppr sty ty])
\end{code}
+
projects / ghc-hetmet.git / blobdiff