{-# LANGUAGE ConstraintKinds #-} {-| Module : GHC.Hs.Utils Description : Generic helpers for the HsSyn type. Copyright : (c) The University of Glasgow, 1992-2006 Here we collect a variety of helper functions that construct or analyse HsSyn. All these functions deal with generic HsSyn; functions which deal with the instantiated versions are located elsewhere: Parameterised by Module ---------------- ------------- GhcPs/RdrName GHC.Parser.PostProcess GhcRn/Name GHC.Rename.* GhcTc/Id GHC.Tc.Utils.Zonk The @mk*@ functions attempt to construct a not-completely-useless SrcSpan from their components, compared with the @nl*@ functions which just attach noSrcSpan to everything. -} {-# LANGUAGE CPP #-} {-# LANGUAGE AllowAmbiguousTypes #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE LambdaCase #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE PatternSynonyms #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE TypeApplications #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE ViewPatterns #-} {-# OPTIONS_GHC -Wno-incomplete-record-updates #-} module GHC.Hs.Utils( -- * Terms mkHsPar, mkHsApp, mkHsAppWith, mkHsApps, mkHsAppsWith, mkHsAppType, mkHsAppTypes, mkHsCaseAlt, mkSimpleMatch, unguardedGRHSs, unguardedRHS, mkMatchGroup, mkLamCaseMatchGroup, mkMatch, mkPrefixFunRhs, mkHsLam, mkHsIf, mkHsWrap, mkLHsWrap, mkHsWrapCo, mkHsWrapCoR, mkLHsWrapCo, mkHsDictLet, mkHsLams, mkHsOpApp, mkHsDo, mkHsDoAnns, mkHsComp, mkHsCompAnns, mkHsWrapPat, mkHsWrapPatCo, mkLHsPar, mkHsCmdWrap, mkLHsCmdWrap, mkHsCmdIf, mkConLikeTc, nlHsTyApp, nlHsTyApps, nlHsVar, nl_HsVar, nlHsDataCon, nlHsLit, nlHsApp, nlHsApps, nlHsSyntaxApps, nlHsIntLit, nlHsVarApps, nlHsDo, nlHsOpApp, nlHsLam, nlHsPar, nlHsIf, nlHsCase, nlList, mkLHsTupleExpr, mkLHsVarTuple, missingTupArg, mkLocatedList, -- * Constructing general big tuples -- $big_tuples mkChunkified, chunkify, -- * Bindings mkFunBind, mkVarBind, mkHsVarBind, mkSimpleGeneratedFunBind, mkTopFunBind, mkPatSynBind, isInfixFunBind, spanHsLocaLBinds, -- * Literals mkHsIntegral, mkHsFractional, mkHsIsString, mkHsString, mkHsStringPrimLit, mkHsCharPrimLit, -- * Patterns mkNPat, mkNPlusKPat, nlVarPat, nlLitPat, nlConVarPat, nlConVarPatName, nlConPat, nlConPatName, nlInfixConPat, nlNullaryConPat, nlWildConPat, nlWildPat, nlWildPatName, nlTuplePat, mkParPat, nlParPat, mkBigLHsVarTup, mkBigLHsTup, mkBigLHsVarPatTup, mkBigLHsPatTup, -- * Types mkHsAppTy, mkHsAppKindTy, hsTypeToHsSigType, hsTypeToHsSigWcType, mkClassOpSigs, mkHsSigEnv, nlHsAppTy, nlHsAppKindTy, nlHsTyVar, nlHsFunTy, nlHsParTy, nlHsTyConApp, -- * Stmts mkTransformStmt, mkTransformByStmt, mkBodyStmt, mkPsBindStmt, mkRnBindStmt, mkTcBindStmt, mkLastStmt, emptyTransStmt, mkGroupUsingStmt, mkGroupByUsingStmt, emptyRecStmt, emptyRecStmtName, emptyRecStmtId, mkRecStmt, unitRecStmtTc, mkLetStmt, -- * Template Haskell mkUntypedSplice, mkTypedSplice, mkHsQuasiQuote, -- * Collecting binders isUnliftedHsBind, isBangedHsBind, collectLocalBinders, collectHsValBinders, collectHsBindListBinders, collectHsIdBinders, collectHsBindsBinders, collectHsBindBinders, collectMethodBinders, collectPatBinders, collectPatsBinders, collectLStmtsBinders, collectStmtsBinders, collectLStmtBinders, collectStmtBinders, CollectPass(..), CollectFlag(..), hsLTyClDeclBinders, hsTyClForeignBinders, hsPatSynSelectors, getPatSynBinds, hsForeignDeclsBinders, hsGroupBinders, hsDataFamInstBinders, -- * Collecting implicit binders lStmtsImplicits, hsValBindsImplicits, lPatImplicits ) where import GHC.Prelude import GHC.Hs.Decls import GHC.Hs.Binds import GHC.Hs.Expr import GHC.Hs.Pat import GHC.Hs.Type import GHC.Hs.Lit import Language.Haskell.Syntax.Extension import GHC.Hs.Extension import GHC.Parser.Annotation import GHC.Tc.Types.Evidence import GHC.Core.TyCo.Rep import GHC.Core.Multiplicity ( pattern Many ) import GHC.Builtin.Types ( unitTy ) import GHC.Tc.Utils.TcType import GHC.Core.DataCon import GHC.Core.ConLike import GHC.Types.Id import GHC.Types.Name import GHC.Types.Name.Set hiding ( unitFV ) import GHC.Types.Name.Env import GHC.Types.Name.Reader import GHC.Types.Var import GHC.Types.Basic import GHC.Types.SrcLoc import GHC.Types.Fixity import GHC.Types.SourceText import GHC.Data.FastString import GHC.Data.Bag import GHC.Settings.Constants import GHC.Utils.Misc import GHC.Utils.Outputable import GHC.Utils.Panic import Data.Either import Data.Function import Data.List ( partition, deleteBy ) {- ************************************************************************ * * Some useful helpers for constructing syntax * * ************************************************************************ These functions attempt to construct a not-completely-useless 'SrcSpan' from their components, compared with the @nl*@ functions below which just attach 'noSrcSpan' to everything. -} -- | @e => (e)@ mkHsPar :: LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) mkHsPar e = L (getLoc e) (gHsPar e) mkSimpleMatch :: (Anno (Match (GhcPass p) (LocatedA (body (GhcPass p)))) ~ SrcSpanAnnA, Anno (GRHS (GhcPass p) (LocatedA (body (GhcPass p)))) ~ SrcAnn NoEpAnns) => HsMatchContext (GhcPass p) -> [LPat (GhcPass p)] -> LocatedA (body (GhcPass p)) -> LMatch (GhcPass p) (LocatedA (body (GhcPass p))) mkSimpleMatch ctxt pats rhs = L loc $ Match { m_ext = noAnn, m_ctxt = ctxt, m_pats = pats , m_grhss = unguardedGRHSs (locA loc) rhs noAnn } where loc = case pats of [] -> getLoc rhs (pat:_) -> combineSrcSpansA (getLoc pat) (getLoc rhs) unguardedGRHSs :: Anno (GRHS (GhcPass p) (LocatedA (body (GhcPass p)))) ~ SrcAnn NoEpAnns => SrcSpan -> LocatedA (body (GhcPass p)) -> EpAnn GrhsAnn -> GRHSs (GhcPass p) (LocatedA (body (GhcPass p))) unguardedGRHSs loc rhs an = GRHSs emptyComments (unguardedRHS an loc rhs) emptyLocalBinds unguardedRHS :: Anno (GRHS (GhcPass p) (LocatedA (body (GhcPass p)))) ~ SrcAnn NoEpAnns => EpAnn GrhsAnn -> SrcSpan -> LocatedA (body (GhcPass p)) -> [LGRHS (GhcPass p) (LocatedA (body (GhcPass p)))] unguardedRHS an loc rhs = [L (noAnnSrcSpan loc) (GRHS an [] rhs)] type AnnoBody p body = ( XMG (GhcPass p) (LocatedA (body (GhcPass p))) ~ Origin , Anno [LocatedA (Match (GhcPass p) (LocatedA (body (GhcPass p))))] ~ SrcSpanAnnL , Anno (Match (GhcPass p) (LocatedA (body (GhcPass p)))) ~ SrcSpanAnnA ) mkMatchGroup :: AnnoBody p body => Origin -> LocatedL [LocatedA (Match (GhcPass p) (LocatedA (body (GhcPass p))))] -> MatchGroup (GhcPass p) (LocatedA (body (GhcPass p))) mkMatchGroup origin matches = MG { mg_ext = origin , mg_alts = matches } mkLamCaseMatchGroup :: AnnoBody p body => Origin -> LamCaseVariant -> LocatedL [LocatedA (Match (GhcPass p) (LocatedA (body (GhcPass p))))] -> MatchGroup (GhcPass p) (LocatedA (body (GhcPass p))) mkLamCaseMatchGroup origin lc_variant (L l matches) = mkMatchGroup origin (L l $ map fixCtxt matches) where fixCtxt (L a match) = L a match{m_ctxt = LamCaseAlt lc_variant} mkLocatedList :: Semigroup a => [GenLocated (SrcAnn a) e2] -> LocatedAn an [GenLocated (SrcAnn a) e2] mkLocatedList [] = noLocA [] mkLocatedList ms = L (noAnnSrcSpan $ locA $ combineLocsA (head ms) (last ms)) ms mkHsApp :: LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) mkHsApp e1 e2 = addCLocAA e1 e2 (HsApp noComments e1 e2) mkHsAppWith :: (LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -> HsExpr (GhcPass id) -> LHsExpr (GhcPass id)) -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) mkHsAppWith mkLocated e1 e2 = mkLocated e1 e2 (HsApp noAnn e1 e2) mkHsApps :: LHsExpr (GhcPass id) -> [LHsExpr (GhcPass id)] -> LHsExpr (GhcPass id) mkHsApps = mkHsAppsWith addCLocAA mkHsAppsWith :: (LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -> HsExpr (GhcPass id) -> LHsExpr (GhcPass id)) -> LHsExpr (GhcPass id) -> [LHsExpr (GhcPass id)] -> LHsExpr (GhcPass id) mkHsAppsWith mkLocated = foldl' (mkHsAppWith mkLocated) mkHsAppType :: LHsExpr GhcRn -> LHsWcType GhcRn -> LHsExpr GhcRn mkHsAppType e t = addCLocAA t_body e (HsAppType noExtField e paren_wct) where t_body = hswc_body t paren_wct = t { hswc_body = parenthesizeHsType appPrec t_body } mkHsAppTypes :: LHsExpr GhcRn -> [LHsWcType GhcRn] -> LHsExpr GhcRn mkHsAppTypes = foldl' mkHsAppType mkHsLam :: (IsPass p, XMG (GhcPass p) (LHsExpr (GhcPass p)) ~ Origin) => [LPat (GhcPass p)] -> LHsExpr (GhcPass p) -> LHsExpr (GhcPass p) mkHsLam pats body = mkHsPar (L (getLoc body) (HsLam noExtField matches)) where matches = mkMatchGroup Generated (noLocA [mkSimpleMatch LambdaExpr pats' body]) pats' = map (parenthesizePat appPrec) pats mkHsLams :: [TyVar] -> [EvVar] -> LHsExpr GhcTc -> LHsExpr GhcTc mkHsLams tyvars dicts expr = mkLHsWrap (mkWpTyLams tyvars <.> mkWpLams dicts) expr -- |A simple case alternative with a single pattern, no binds, no guards; -- pre-typechecking mkHsCaseAlt :: (Anno (GRHS (GhcPass p) (LocatedA (body (GhcPass p)))) ~ SrcAnn NoEpAnns, Anno (Match (GhcPass p) (LocatedA (body (GhcPass p)))) ~ SrcSpanAnnA) => LPat (GhcPass p) -> (LocatedA (body (GhcPass p))) -> LMatch (GhcPass p) (LocatedA (body (GhcPass p))) mkHsCaseAlt pat expr = mkSimpleMatch CaseAlt [pat] expr nlHsTyApp :: Id -> [Type] -> LHsExpr GhcTc nlHsTyApp fun_id tys = noLocA (mkHsWrap (mkWpTyApps tys) (HsVar noExtField (noLocA fun_id))) nlHsTyApps :: Id -> [Type] -> [LHsExpr GhcTc] -> LHsExpr GhcTc nlHsTyApps fun_id tys xs = foldl' nlHsApp (nlHsTyApp fun_id tys) xs --------- Adding parens --------- -- | Wrap in parens if @'hsExprNeedsParens' appPrec@ says it needs them -- So @f x@ becomes @(f x)@, but @3@ stays as @3@. mkLHsPar :: IsPass id => LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) mkLHsPar = parenthesizeHsExpr appPrec mkParPat :: IsPass p => LPat (GhcPass p) -> LPat (GhcPass p) mkParPat = parenthesizePat appPrec nlParPat :: LPat (GhcPass name) -> LPat (GhcPass name) nlParPat p = noLocA (gParPat p) ------------------------------- -- These are the bits of syntax that contain rebindable names -- See GHC.Rename.Env.lookupSyntax mkHsIntegral :: IntegralLit -> HsOverLit GhcPs mkHsFractional :: FractionalLit -> HsOverLit GhcPs mkHsIsString :: SourceText -> FastString -> HsOverLit GhcPs mkHsDo :: HsDoFlavour -> LocatedL [ExprLStmt GhcPs] -> HsExpr GhcPs mkHsDoAnns :: HsDoFlavour -> LocatedL [ExprLStmt GhcPs] -> EpAnn AnnList -> HsExpr GhcPs mkHsComp :: HsDoFlavour -> [ExprLStmt GhcPs] -> LHsExpr GhcPs -> HsExpr GhcPs mkHsCompAnns :: HsDoFlavour -> [ExprLStmt GhcPs] -> LHsExpr GhcPs -> EpAnn AnnList -> HsExpr GhcPs mkNPat :: LocatedAn NoEpAnns (HsOverLit GhcPs) -> Maybe (SyntaxExpr GhcPs) -> EpAnn [AddEpAnn] -> Pat GhcPs mkNPlusKPat :: LocatedN RdrName -> LocatedAn NoEpAnns (HsOverLit GhcPs) -> EpAnn EpaLocation -> Pat GhcPs -- NB: The following functions all use noSyntaxExpr: the generated expressions -- will not work with rebindable syntax if used after the renamer mkLastStmt :: IsPass idR => LocatedA (bodyR (GhcPass idR)) -> StmtLR (GhcPass idL) (GhcPass idR) (LocatedA (bodyR (GhcPass idR))) mkBodyStmt :: LocatedA (bodyR GhcPs) -> StmtLR (GhcPass idL) GhcPs (LocatedA (bodyR GhcPs)) mkPsBindStmt :: EpAnn [AddEpAnn] -> LPat GhcPs -> LocatedA (bodyR GhcPs) -> StmtLR GhcPs GhcPs (LocatedA (bodyR GhcPs)) mkRnBindStmt :: LPat GhcRn -> LocatedA (bodyR GhcRn) -> StmtLR GhcRn GhcRn (LocatedA (bodyR GhcRn)) mkTcBindStmt :: LPat GhcTc -> LocatedA (bodyR GhcTc) -> StmtLR GhcTc GhcTc (LocatedA (bodyR GhcTc)) emptyRecStmt :: (Anno [GenLocated (Anno (StmtLR (GhcPass idL) GhcPs bodyR)) (StmtLR (GhcPass idL) GhcPs bodyR)] ~ SrcSpanAnnL) => StmtLR (GhcPass idL) GhcPs bodyR emptyRecStmtName :: (Anno [GenLocated (Anno (StmtLR GhcRn GhcRn bodyR)) (StmtLR GhcRn GhcRn bodyR)] ~ SrcSpanAnnL) => StmtLR GhcRn GhcRn bodyR emptyRecStmtId :: Stmt GhcTc (LocatedA (HsCmd GhcTc)) mkRecStmt :: forall (idL :: Pass) bodyR. (Anno [GenLocated (Anno (StmtLR (GhcPass idL) GhcPs bodyR)) (StmtLR (GhcPass idL) GhcPs bodyR)] ~ SrcSpanAnnL) => EpAnn AnnList -> LocatedL [LStmtLR (GhcPass idL) GhcPs bodyR] -> StmtLR (GhcPass idL) GhcPs bodyR mkRecStmt anns stmts = (emptyRecStmt' anns :: StmtLR (GhcPass idL) GhcPs bodyR) { recS_stmts = stmts } mkHsIntegral i = OverLit noExtField (HsIntegral i) mkHsFractional f = OverLit noExtField (HsFractional f) mkHsIsString src s = OverLit noExtField (HsIsString src s) mkHsDo ctxt stmts = HsDo noAnn ctxt stmts mkHsDoAnns ctxt stmts anns = HsDo anns ctxt stmts mkHsComp ctxt stmts expr = mkHsCompAnns ctxt stmts expr noAnn mkHsCompAnns ctxt stmts expr anns = mkHsDoAnns ctxt (mkLocatedList (stmts ++ [last_stmt])) anns where -- Strip the annotations from the location, they are in the embedded expr last_stmt = L (noAnnSrcSpan $ getLocA expr) $ mkLastStmt expr -- restricted to GhcPs because other phases might need a SyntaxExpr mkHsIf :: LHsExpr GhcPs -> LHsExpr GhcPs -> LHsExpr GhcPs -> EpAnn AnnsIf -> HsExpr GhcPs mkHsIf c a b anns = HsIf anns c a b -- restricted to GhcPs because other phases might need a SyntaxExpr mkHsCmdIf :: LHsExpr GhcPs -> LHsCmd GhcPs -> LHsCmd GhcPs -> EpAnn AnnsIf -> HsCmd GhcPs mkHsCmdIf c a b anns = HsCmdIf anns noSyntaxExpr c a b mkNPat lit neg anns = NPat anns lit neg noSyntaxExpr mkNPlusKPat id lit anns = NPlusKPat anns id lit (unLoc lit) noSyntaxExpr noSyntaxExpr mkTransformStmt :: EpAnn [AddEpAnn] -> [ExprLStmt GhcPs] -> LHsExpr GhcPs -> StmtLR GhcPs GhcPs (LHsExpr GhcPs) mkTransformByStmt :: EpAnn [AddEpAnn] -> [ExprLStmt GhcPs] -> LHsExpr GhcPs -> LHsExpr GhcPs -> StmtLR GhcPs GhcPs (LHsExpr GhcPs) mkGroupUsingStmt :: EpAnn [AddEpAnn] -> [ExprLStmt GhcPs] -> LHsExpr GhcPs -> StmtLR GhcPs GhcPs (LHsExpr GhcPs) mkGroupByUsingStmt :: EpAnn [AddEpAnn] -> [ExprLStmt GhcPs] -> LHsExpr GhcPs -> LHsExpr GhcPs -> StmtLR GhcPs GhcPs (LHsExpr GhcPs) emptyTransStmt :: EpAnn [AddEpAnn] -> StmtLR GhcPs GhcPs (LHsExpr GhcPs) emptyTransStmt anns = TransStmt { trS_ext = anns , trS_form = panic "emptyTransStmt: form" , trS_stmts = [], trS_bndrs = [] , trS_by = Nothing, trS_using = noLocA noExpr , trS_ret = noSyntaxExpr, trS_bind = noSyntaxExpr , trS_fmap = noExpr } mkTransformStmt a ss u = (emptyTransStmt a) { trS_form = ThenForm, trS_stmts = ss, trS_using = u } mkTransformByStmt a ss u b = (emptyTransStmt a) { trS_form = ThenForm, trS_stmts = ss, trS_using = u, trS_by = Just b } mkGroupUsingStmt a ss u = (emptyTransStmt a) { trS_form = GroupForm, trS_stmts = ss, trS_using = u } mkGroupByUsingStmt a ss b u = (emptyTransStmt a) { trS_form = GroupForm, trS_stmts = ss, trS_using = u, trS_by = Just b } mkLastStmt body = LastStmt noExtField body Nothing noSyntaxExpr mkBodyStmt body = BodyStmt noExtField body noSyntaxExpr noSyntaxExpr mkPsBindStmt ann pat body = BindStmt ann pat body mkRnBindStmt pat body = BindStmt (XBindStmtRn { xbsrn_bindOp = noSyntaxExpr, xbsrn_failOp = Nothing }) pat body mkTcBindStmt pat body = BindStmt (XBindStmtTc { xbstc_bindOp = noSyntaxExpr, xbstc_boundResultType = unitTy, -- unitTy is a dummy value -- can't panic here: it's forced during zonking xbstc_boundResultMult = Many, xbstc_failOp = Nothing }) pat body emptyRecStmt' :: forall idL idR body . (WrapXRec (GhcPass idR) [LStmtLR (GhcPass idL) (GhcPass idR) body], IsPass idR) => XRecStmt (GhcPass idL) (GhcPass idR) body -> StmtLR (GhcPass idL) (GhcPass idR) body emptyRecStmt' tyVal = RecStmt { recS_stmts = wrapXRec @(GhcPass idR) [] , recS_later_ids = [] , recS_rec_ids = [] , recS_ret_fn = noSyntaxExpr , recS_mfix_fn = noSyntaxExpr , recS_bind_fn = noSyntaxExpr , recS_ext = tyVal } unitRecStmtTc :: RecStmtTc unitRecStmtTc = RecStmtTc { recS_bind_ty = unitTy , recS_later_rets = [] , recS_rec_rets = [] , recS_ret_ty = unitTy } emptyRecStmt = emptyRecStmt' noAnn emptyRecStmtName = emptyRecStmt' noExtField emptyRecStmtId = emptyRecStmt' unitRecStmtTc -- a panic might trigger during zonking mkLetStmt :: EpAnn [AddEpAnn] -> HsLocalBinds GhcPs -> StmtLR GhcPs GhcPs (LocatedA b) mkLetStmt anns binds = LetStmt anns binds ------------------------------- -- | A useful function for building @OpApps@. The operator is always a -- variable, and we don't know the fixity yet. mkHsOpApp :: LHsExpr GhcPs -> IdP GhcPs -> LHsExpr GhcPs -> HsExpr GhcPs mkHsOpApp e1 op e2 = OpApp noAnn e1 (noLocA (HsVar noExtField (noLocA op))) e2 unqualSplice :: RdrName unqualSplice = mkRdrUnqual (mkVarOccFS (fsLit "splice")) mkUntypedSplice :: EpAnn [AddEpAnn] -> SpliceDecoration -> LHsExpr GhcPs -> HsSplice GhcPs mkUntypedSplice ann hasParen e = HsUntypedSplice ann hasParen unqualSplice e mkTypedSplice :: EpAnn [AddEpAnn] -> SpliceDecoration -> LHsExpr GhcPs -> HsSplice GhcPs mkTypedSplice ann hasParen e = HsTypedSplice ann hasParen unqualSplice e mkHsQuasiQuote :: RdrName -> SrcSpan -> FastString -> HsSplice GhcPs mkHsQuasiQuote quoter span quote = HsQuasiQuote noExtField unqualSplice quoter span quote mkHsString :: String -> HsLit (GhcPass p) mkHsString s = HsString NoSourceText (mkFastString s) mkHsStringPrimLit :: FastString -> HsLit (GhcPass p) mkHsStringPrimLit fs = HsStringPrim NoSourceText (bytesFS fs) mkHsCharPrimLit :: Char -> HsLit (GhcPass p) mkHsCharPrimLit c = HsChar NoSourceText c mkConLikeTc :: ConLike -> HsExpr GhcTc mkConLikeTc con = XExpr (ConLikeTc con [] []) {- ************************************************************************ * * Constructing syntax with no location info * * ************************************************************************ -} nlHsVar :: IsSrcSpanAnn p a => IdP (GhcPass p) -> LHsExpr (GhcPass p) nlHsVar n = noLocA (HsVar noExtField (noLocA n)) nl_HsVar :: IsSrcSpanAnn p a => IdP (GhcPass p) -> HsExpr (GhcPass p) nl_HsVar n = HsVar noExtField (noLocA n) -- | NB: Only for 'LHsExpr' 'Id'. nlHsDataCon :: DataCon -> LHsExpr GhcTc nlHsDataCon con = noLocA (mkConLikeTc (RealDataCon con)) nlHsLit :: HsLit (GhcPass p) -> LHsExpr (GhcPass p) nlHsLit n = noLocA (HsLit noComments n) nlHsIntLit :: Integer -> LHsExpr (GhcPass p) nlHsIntLit n = noLocA (HsLit noComments (HsInt noExtField (mkIntegralLit n))) nlVarPat :: IsSrcSpanAnn p a => IdP (GhcPass p) -> LPat (GhcPass p) nlVarPat n = noLocA (VarPat noExtField (noLocA n)) nlLitPat :: HsLit GhcPs -> LPat GhcPs nlLitPat l = noLocA (LitPat noExtField l) nlHsApp :: IsPass id => LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) nlHsApp f x = noLocA (HsApp noComments f (mkLHsPar x)) nlHsSyntaxApps :: SyntaxExprTc -> [LHsExpr GhcTc] -> LHsExpr GhcTc nlHsSyntaxApps (SyntaxExprTc { syn_expr = fun , syn_arg_wraps = arg_wraps , syn_res_wrap = res_wrap }) args = mkLHsWrap res_wrap (foldl' nlHsApp (noLocA fun) (zipWithEqual "nlHsSyntaxApps" mkLHsWrap arg_wraps args)) nlHsSyntaxApps NoSyntaxExprTc args = pprPanic "nlHsSyntaxApps" (ppr args) -- this function should never be called in scenarios where there is no -- syntax expr nlHsApps :: IsSrcSpanAnn p a => IdP (GhcPass p) -> [LHsExpr (GhcPass p)] -> LHsExpr (GhcPass p) nlHsApps f xs = foldl' nlHsApp (nlHsVar f) xs nlHsVarApps :: IsSrcSpanAnn p a => IdP (GhcPass p) -> [IdP (GhcPass p)] -> LHsExpr (GhcPass p) nlHsVarApps f xs = noLocA (foldl' mk (HsVar noExtField (noLocA f)) (map ((HsVar noExtField) . noLocA) xs)) where mk f a = HsApp noComments (noLocA f) (noLocA a) nlConVarPat :: RdrName -> [RdrName] -> LPat GhcPs nlConVarPat con vars = nlConPat con (map nlVarPat vars) nlConVarPatName :: Name -> [Name] -> LPat GhcRn nlConVarPatName con vars = nlConPatName con (map nlVarPat vars) nlInfixConPat :: RdrName -> LPat GhcPs -> LPat GhcPs -> LPat GhcPs nlInfixConPat con l r = noLocA $ ConPat { pat_con = noLocA con , pat_args = InfixCon (parenthesizePat opPrec l) (parenthesizePat opPrec r) , pat_con_ext = noAnn } nlConPat :: RdrName -> [LPat GhcPs] -> LPat GhcPs nlConPat con pats = noLocA $ ConPat { pat_con_ext = noAnn , pat_con = noLocA con , pat_args = PrefixCon [] (map (parenthesizePat appPrec) pats) } nlConPatName :: Name -> [LPat GhcRn] -> LPat GhcRn nlConPatName con pats = noLocA $ ConPat { pat_con_ext = noExtField , pat_con = noLocA con , pat_args = PrefixCon [] (map (parenthesizePat appPrec) pats) } nlNullaryConPat :: RdrName -> LPat GhcPs nlNullaryConPat con = noLocA $ ConPat { pat_con_ext = noAnn , pat_con = noLocA con , pat_args = PrefixCon [] [] } nlWildConPat :: DataCon -> LPat GhcPs nlWildConPat con = noLocA $ ConPat { pat_con_ext = noAnn , pat_con = noLocA $ getRdrName con , pat_args = PrefixCon [] $ replicate (dataConSourceArity con) nlWildPat } -- | Wildcard pattern - after parsing nlWildPat :: LPat GhcPs nlWildPat = noLocA (WildPat noExtField ) -- | Wildcard pattern - after renaming nlWildPatName :: LPat GhcRn nlWildPatName = noLocA (WildPat noExtField ) nlHsDo :: HsDoFlavour -> [LStmt GhcPs (LHsExpr GhcPs)] -> LHsExpr GhcPs nlHsDo ctxt stmts = noLocA (mkHsDo ctxt (noLocA stmts)) nlHsOpApp :: LHsExpr GhcPs -> IdP GhcPs -> LHsExpr GhcPs -> LHsExpr GhcPs nlHsOpApp e1 op e2 = noLocA (mkHsOpApp e1 op e2) nlHsLam :: LMatch GhcPs (LHsExpr GhcPs) -> LHsExpr GhcPs nlHsPar :: LHsExpr (GhcPass id) -> LHsExpr (GhcPass id) nlHsCase :: LHsExpr GhcPs -> [LMatch GhcPs (LHsExpr GhcPs)] -> LHsExpr GhcPs nlList :: [LHsExpr GhcPs] -> LHsExpr GhcPs -- AZ:Is this used? nlHsLam match = noLocA (HsLam noExtField (mkMatchGroup Generated (noLocA [match]))) nlHsPar e = noLocA (gHsPar e) -- nlHsIf should generate if-expressions which are NOT subject to -- RebindableSyntax, so the first field of HsIf is False. (#12080) nlHsIf :: LHsExpr GhcPs -> LHsExpr GhcPs -> LHsExpr GhcPs -> LHsExpr GhcPs nlHsIf cond true false = noLocA (HsIf noAnn cond true false) nlHsCase expr matches = noLocA (HsCase noAnn expr (mkMatchGroup Generated (noLocA matches))) nlList exprs = noLocA (ExplicitList noAnn exprs) nlHsAppTy :: LHsType (GhcPass p) -> LHsType (GhcPass p) -> LHsType (GhcPass p) nlHsTyVar :: IsSrcSpanAnn p a => PromotionFlag -> IdP (GhcPass p) -> LHsType (GhcPass p) nlHsFunTy :: LHsType (GhcPass p) -> LHsType (GhcPass p) -> LHsType (GhcPass p) nlHsParTy :: LHsType (GhcPass p) -> LHsType (GhcPass p) nlHsAppTy f t = noLocA (HsAppTy noExtField f (parenthesizeHsType appPrec t)) nlHsTyVar p x = noLocA (HsTyVar noAnn p (noLocA x)) nlHsFunTy a b = noLocA (HsFunTy noAnn (HsUnrestrictedArrow noHsUniTok) (parenthesizeHsType funPrec a) b) nlHsParTy t = noLocA (HsParTy noAnn t) nlHsTyConApp :: IsSrcSpanAnn p a => PromotionFlag -> LexicalFixity -> IdP (GhcPass p) -> [LHsTypeArg (GhcPass p)] -> LHsType (GhcPass p) nlHsTyConApp prom fixity tycon tys | Infix <- fixity , HsValArg ty1 : HsValArg ty2 : rest <- tys = foldl' mk_app (noLocA $ HsOpTy noAnn prom ty1 (noLocA tycon) ty2) rest | otherwise = foldl' mk_app (nlHsTyVar prom tycon) tys where mk_app :: LHsType (GhcPass p) -> LHsTypeArg (GhcPass p) -> LHsType (GhcPass p) mk_app fun@(L _ (HsOpTy {})) arg = mk_app (noLocA $ HsParTy noAnn fun) arg -- parenthesize things like `(A + B) C` mk_app fun (HsValArg ty) = noLocA (HsAppTy noExtField fun (parenthesizeHsType appPrec ty)) mk_app fun (HsTypeArg _ ki) = noLocA (HsAppKindTy noSrcSpan fun (parenthesizeHsType appPrec ki)) mk_app fun (HsArgPar _) = noLocA (HsParTy noAnn fun) nlHsAppKindTy :: LHsType (GhcPass p) -> LHsKind (GhcPass p) -> LHsType (GhcPass p) nlHsAppKindTy f k = noLocA (HsAppKindTy noSrcSpan f (parenthesizeHsType appPrec k)) {- Tuples. All these functions are *pre-typechecker* because they lack types on the tuple. -} mkLHsTupleExpr :: [LHsExpr (GhcPass p)] -> XExplicitTuple (GhcPass p) -> LHsExpr (GhcPass p) -- Makes a pre-typechecker boxed tuple, deals with 1 case mkLHsTupleExpr [e] _ = e mkLHsTupleExpr es ext = noLocA $ ExplicitTuple ext (map (Present noAnn) es) Boxed mkLHsVarTuple :: IsSrcSpanAnn p a => [IdP (GhcPass p)] -> XExplicitTuple (GhcPass p) -> LHsExpr (GhcPass p) mkLHsVarTuple ids ext = mkLHsTupleExpr (map nlHsVar ids) ext nlTuplePat :: [LPat GhcPs] -> Boxity -> LPat GhcPs nlTuplePat pats box = noLocA (TuplePat noAnn pats box) missingTupArg :: EpAnn EpaLocation -> HsTupArg GhcPs missingTupArg ann = Missing ann mkLHsPatTup :: [LPat GhcRn] -> LPat GhcRn mkLHsPatTup [] = noLocA $ TuplePat noExtField [] Boxed mkLHsPatTup [lpat] = lpat mkLHsPatTup lpats = L (getLoc (head lpats)) $ TuplePat noExtField lpats Boxed -- | The Big equivalents for the source tuple expressions mkBigLHsVarTup :: IsSrcSpanAnn p a => [IdP (GhcPass p)] -> XExplicitTuple (GhcPass p) -> LHsExpr (GhcPass p) mkBigLHsVarTup ids anns = mkBigLHsTup (map nlHsVar ids) anns mkBigLHsTup :: [LHsExpr (GhcPass id)] -> XExplicitTuple (GhcPass id) -> LHsExpr (GhcPass id) mkBigLHsTup es anns = mkChunkified (\e -> mkLHsTupleExpr e anns) es -- | The Big equivalents for the source tuple patterns mkBigLHsVarPatTup :: [IdP GhcRn] -> LPat GhcRn mkBigLHsVarPatTup bs = mkBigLHsPatTup (map nlVarPat bs) mkBigLHsPatTup :: [LPat GhcRn] -> LPat GhcRn mkBigLHsPatTup = mkChunkified mkLHsPatTup -- $big_tuples -- #big_tuples# -- -- GHCs built in tuples can only go up to 'mAX_TUPLE_SIZE' in arity, but -- we might conceivably want to build such a massive tuple as part of the -- output of a desugaring stage (notably that for list comprehensions). -- -- We call tuples above this size \"big tuples\", and emulate them by -- creating and pattern matching on >nested< tuples that are expressible -- by GHC. -- -- Nesting policy: it's better to have a 2-tuple of 10-tuples (3 objects) -- than a 10-tuple of 2-tuples (11 objects), so we want the leaves of any -- construction to be big. -- -- If you just use the 'mkBigCoreTup', 'mkBigCoreVarTupTy', 'mkTupleSelector' -- and 'mkTupleCase' functions to do all your work with tuples you should be -- fine, and not have to worry about the arity limitation at all. -- | Lifts a \"small\" constructor into a \"big\" constructor by recursive decomposition mkChunkified :: ([a] -> a) -- ^ \"Small\" constructor function, of maximum input arity 'mAX_TUPLE_SIZE' -> [a] -- ^ Possible \"big\" list of things to construct from -> a -- ^ Constructed thing made possible by recursive decomposition mkChunkified small_tuple as = mk_big_tuple (chunkify as) where -- Each sub-list is short enough to fit in a tuple mk_big_tuple [as] = small_tuple as mk_big_tuple as_s = mk_big_tuple (chunkify (map small_tuple as_s)) chunkify :: [a] -> [[a]] -- ^ Split a list into lists that are small enough to have a corresponding -- tuple arity. The sub-lists of the result all have length <= 'mAX_TUPLE_SIZE' -- But there may be more than 'mAX_TUPLE_SIZE' sub-lists chunkify xs | n_xs <= mAX_TUPLE_SIZE = [xs] | otherwise = split xs where n_xs = length xs split [] = [] split xs = take mAX_TUPLE_SIZE xs : split (drop mAX_TUPLE_SIZE xs) {- ************************************************************************ * * LHsSigType and LHsSigWcType * * ********************************************************************* -} -- | Convert an 'LHsType' to an 'LHsSigType'. hsTypeToHsSigType :: LHsType GhcPs -> LHsSigType GhcPs hsTypeToHsSigType lty@(L loc ty) = L loc $ case ty of HsForAllTy { hst_tele = HsForAllInvis { hsf_xinvis = an , hsf_invis_bndrs = bndrs } , hst_body = body } -> mkHsExplicitSigType an bndrs body _ -> mkHsImplicitSigType lty -- | Convert an 'LHsType' to an 'LHsSigWcType'. hsTypeToHsSigWcType :: LHsType GhcPs -> LHsSigWcType GhcPs hsTypeToHsSigWcType = mkHsWildCardBndrs . hsTypeToHsSigType mkHsSigEnv :: forall a. (LSig GhcRn -> Maybe ([LocatedN Name], a)) -> [LSig GhcRn] -> NameEnv a mkHsSigEnv get_info sigs = mkNameEnv (mk_pairs ordinary_sigs) `extendNameEnvList` (mk_pairs gen_dm_sigs) -- The subtlety is this: in a class decl with a -- default-method signature as well as a method signature -- we want the latter to win (#12533) -- class C x where -- op :: forall a . x a -> x a -- default op :: forall b . x b -> x b -- op x = ...(e :: b -> b)... -- The scoped type variables of the 'default op', namely 'b', -- scope over the code for op. The 'forall a' does not! -- This applies both in the renamer and typechecker, both -- of which use this function where (gen_dm_sigs, ordinary_sigs) = partition is_gen_dm_sig sigs is_gen_dm_sig (L _ (ClassOpSig _ True _ _)) = True is_gen_dm_sig _ = False mk_pairs :: [LSig GhcRn] -> [(Name, a)] mk_pairs sigs = [ (n,a) | Just (ns,a) <- map get_info sigs , L _ n <- ns ] mkClassOpSigs :: [LSig GhcPs] -> [LSig GhcPs] -- ^ Convert 'TypeSig' to 'ClassOpSig'. -- The former is what is parsed, but the latter is -- what we need in class/instance declarations mkClassOpSigs sigs = map fiddle sigs where fiddle (L loc (TypeSig anns nms ty)) = L loc (ClassOpSig anns False nms (dropWildCards ty)) fiddle sig = sig {- ********************************************************************* * * --------- HsWrappers: type args, dict args, casts --------- * * ********************************************************************* -} mkLHsWrap :: HsWrapper -> LHsExpr GhcTc -> LHsExpr GhcTc mkLHsWrap co_fn (L loc e) = L loc (mkHsWrap co_fn e) mkHsWrap :: HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc mkHsWrap co_fn e | isIdHsWrapper co_fn = e mkHsWrap co_fn e = XExpr (WrapExpr $ HsWrap co_fn e) mkHsWrapCo :: TcCoercionN -- A Nominal coercion a ~N b -> HsExpr GhcTc -> HsExpr GhcTc mkHsWrapCo co e = mkHsWrap (mkWpCastN co) e mkHsWrapCoR :: TcCoercionR -- A Representational coercion a ~R b -> HsExpr GhcTc -> HsExpr GhcTc mkHsWrapCoR co e = mkHsWrap (mkWpCastR co) e mkLHsWrapCo :: TcCoercionN -> LHsExpr GhcTc -> LHsExpr GhcTc mkLHsWrapCo co (L loc e) = L loc (mkHsWrapCo co e) mkHsCmdWrap :: HsWrapper -> HsCmd GhcTc -> HsCmd GhcTc mkHsCmdWrap w cmd | isIdHsWrapper w = cmd | otherwise = XCmd (HsWrap w cmd) mkLHsCmdWrap :: HsWrapper -> LHsCmd GhcTc -> LHsCmd GhcTc mkLHsCmdWrap w (L loc c) = L loc (mkHsCmdWrap w c) mkHsWrapPat :: HsWrapper -> Pat GhcTc -> Type -> Pat GhcTc mkHsWrapPat co_fn p ty | isIdHsWrapper co_fn = p | otherwise = XPat $ CoPat co_fn p ty mkHsWrapPatCo :: TcCoercionN -> Pat GhcTc -> Type -> Pat GhcTc mkHsWrapPatCo co pat ty | isTcReflCo co = pat | otherwise = XPat $ CoPat (mkWpCastN co) pat ty mkHsDictLet :: TcEvBinds -> LHsExpr GhcTc -> LHsExpr GhcTc mkHsDictLet ev_binds expr = mkLHsWrap (mkWpLet ev_binds) expr {- l ************************************************************************ * * Bindings; with a location at the top * * ************************************************************************ -} mkFunBind :: Origin -> LocatedN RdrName -> [LMatch GhcPs (LHsExpr GhcPs)] -> HsBind GhcPs -- ^ Not infix, with place holders for coercion and free vars mkFunBind origin fn ms = FunBind { fun_id = fn , fun_matches = mkMatchGroup origin (noLocA ms) , fun_ext = noExtField , fun_tick = [] } mkTopFunBind :: Origin -> LocatedN Name -> [LMatch GhcRn (LHsExpr GhcRn)] -> HsBind GhcRn -- ^ In Name-land, with empty bind_fvs mkTopFunBind origin fn ms = FunBind { fun_id = fn , fun_matches = mkMatchGroup origin (noLocA ms) , fun_ext = emptyNameSet -- NB: closed -- binding , fun_tick = [] } mkHsVarBind :: SrcSpan -> RdrName -> LHsExpr GhcPs -> LHsBind GhcPs mkHsVarBind loc var rhs = mkSimpleGeneratedFunBind loc var [] rhs mkVarBind :: IdP (GhcPass p) -> LHsExpr (GhcPass p) -> LHsBind (GhcPass p) mkVarBind var rhs = L (getLoc rhs) $ VarBind { var_ext = noExtField, var_id = var, var_rhs = rhs } mkPatSynBind :: LocatedN RdrName -> HsPatSynDetails GhcPs -> LPat GhcPs -> HsPatSynDir GhcPs -> EpAnn [AddEpAnn] -> HsBind GhcPs mkPatSynBind name details lpat dir anns = PatSynBind noExtField psb where psb = PSB{ psb_ext = anns , psb_id = name , psb_args = details , psb_def = lpat , psb_dir = dir } -- |If any of the matches in the 'FunBind' are infix, the 'FunBind' is -- considered infix. isInfixFunBind :: forall id1 id2. UnXRec id2 => HsBindLR id1 id2 -> Bool isInfixFunBind (FunBind { fun_matches = MG _ matches }) = any (isInfixMatch . unXRec @id2) (unXRec @id2 matches) isInfixFunBind _ = False -- |Return the 'SrcSpan' encompassing the contents of any enclosed binds spanHsLocaLBinds :: HsLocalBinds (GhcPass p) -> SrcSpan spanHsLocaLBinds (EmptyLocalBinds _) = noSrcSpan spanHsLocaLBinds (HsValBinds _ (ValBinds _ bs sigs)) = foldr combineSrcSpans noSrcSpan (bsSpans ++ sigsSpans) where bsSpans :: [SrcSpan] bsSpans = map getLocA $ bagToList bs sigsSpans :: [SrcSpan] sigsSpans = map getLocA sigs spanHsLocaLBinds (HsValBinds _ (XValBindsLR (NValBinds bs sigs))) = foldr combineSrcSpans noSrcSpan (bsSpans ++ sigsSpans) where bsSpans :: [SrcSpan] bsSpans = map getLocA $ concatMap (bagToList . snd) bs sigsSpans :: [SrcSpan] sigsSpans = map getLocA sigs spanHsLocaLBinds (HsIPBinds _ (IPBinds _ bs)) = foldr combineSrcSpans noSrcSpan (map getLocA bs) ------------ -- | Convenience function using 'mkFunBind'. -- This is for generated bindings only, do not use for user-written code. mkSimpleGeneratedFunBind :: SrcSpan -> RdrName -> [LPat GhcPs] -> LHsExpr GhcPs -> LHsBind GhcPs mkSimpleGeneratedFunBind loc fun pats expr = L (noAnnSrcSpan loc) $ mkFunBind Generated (L (noAnnSrcSpan loc) fun) [mkMatch (mkPrefixFunRhs (L (noAnnSrcSpan loc) fun)) pats expr emptyLocalBinds] -- | Make a prefix, non-strict function 'HsMatchContext' mkPrefixFunRhs :: LIdP p -> HsMatchContext p mkPrefixFunRhs n = FunRhs { mc_fun = n , mc_fixity = Prefix , mc_strictness = NoSrcStrict } ------------ mkMatch :: forall p. IsPass p => HsMatchContext (GhcPass p) -> [LPat (GhcPass p)] -> LHsExpr (GhcPass p) -> HsLocalBinds (GhcPass p) -> LMatch (GhcPass p) (LHsExpr (GhcPass p)) mkMatch ctxt pats expr binds = noLocA (Match { m_ext = noAnn , m_ctxt = ctxt , m_pats = map mkParPat pats , m_grhss = GRHSs emptyComments (unguardedRHS noAnn noSrcSpan expr) binds }) {- ************************************************************************ * * Collecting binders * * ************************************************************************ Get all the binders in some HsBindGroups, IN THE ORDER OF APPEARANCE. eg. ... where (x, y) = ... f i j = ... [a, b] = ... it should return [x, y, f, a, b] (remember, order important). Note [Collect binders only after renaming] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ These functions should only be used on HsSyn *after* the renamer, to return a [Name] or [Id]. Before renaming the record punning and wild-card mechanism makes it hard to know what is bound. So these functions should not be applied to (HsSyn RdrName) Note [Unlifted id check in isUnliftedHsBind] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The function isUnliftedHsBind is used to complain if we make a top-level binding for a variable of unlifted type. Such a binding is illegal if the top-level binding would be unlifted; but also if the local letrec generated by desugaring AbsBinds would be. E.g. f :: Num a => (# a, a #) g :: Num a => a -> a f = ...g... g = ...g... The top-level bindings for f,g are not unlifted (because of the Num a =>), but the local, recursive, monomorphic bindings are: t = /\a \(d:Num a). letrec fm :: (# a, a #) = ...g... gm :: a -> a = ...f... in (fm, gm) Here the binding for 'fm' is illegal. So generally we check the abe_mono types. BUT we have a special case when abs_sig is true; see Note [The abs_sig field of AbsBinds] in GHC.Hs.Binds -} ----------------- Bindings -------------------------- -- | Should we treat this as an unlifted bind? This will be true for any -- bind that binds an unlifted variable, but we must be careful around -- AbsBinds. See Note [Unlifted id check in isUnliftedHsBind]. For usage -- information, see Note [Strict binds checks] is GHC.HsToCore.Binds. isUnliftedHsBind :: HsBind GhcTc -> Bool -- works only over typechecked binds isUnliftedHsBind bind | XHsBindsLR (AbsBinds { abs_exports = exports, abs_sig = has_sig }) <- bind = if has_sig then any (is_unlifted_id . abe_poly) exports else any (is_unlifted_id . abe_mono) exports -- If has_sig is True we will never generate a binding for abe_mono, -- so we don't need to worry about it being unlifted. The abe_poly -- binding might not be: e.g. forall a. Num a => (# a, a #) | otherwise = any is_unlifted_id (collectHsBindBinders CollNoDictBinders bind) where is_unlifted_id id = isUnliftedType (idType id) -- bindings always have a fixed RuntimeRep, so it's OK -- to call isUnliftedType here -- | Is a binding a strict variable or pattern bind (e.g. @!x = ...@)? isBangedHsBind :: HsBind GhcTc -> Bool isBangedHsBind (XHsBindsLR (AbsBinds { abs_binds = binds })) = anyBag (isBangedHsBind . unLoc) binds isBangedHsBind (FunBind {fun_matches = matches}) | [L _ match] <- unLoc $ mg_alts matches , FunRhs{mc_strictness = SrcStrict} <- m_ctxt match = True isBangedHsBind (PatBind {pat_lhs = pat}) = isBangedLPat pat isBangedHsBind _ = False collectLocalBinders :: CollectPass (GhcPass idL) => CollectFlag (GhcPass idL) -> HsLocalBindsLR (GhcPass idL) (GhcPass idR) -> [IdP (GhcPass idL)] collectLocalBinders flag = \case HsValBinds _ binds -> collectHsIdBinders flag binds -- No pattern synonyms here HsIPBinds {} -> [] EmptyLocalBinds _ -> [] collectHsIdBinders :: CollectPass (GhcPass idL) => CollectFlag (GhcPass idL) -> HsValBindsLR (GhcPass idL) (GhcPass idR) -> [IdP (GhcPass idL)] -- ^ Collect 'Id' binders only, or 'Id's + pattern synonyms, respectively collectHsIdBinders flag = collect_hs_val_binders True flag collectHsValBinders :: CollectPass (GhcPass idL) => CollectFlag (GhcPass idL) -> HsValBindsLR (GhcPass idL) idR -> [IdP (GhcPass idL)] collectHsValBinders flag = collect_hs_val_binders False flag collectHsBindBinders :: CollectPass p => CollectFlag p -> HsBindLR p idR -> [IdP p] -- ^ Collect both 'Id's and pattern-synonym binders collectHsBindBinders flag b = collect_bind False flag b [] collectHsBindsBinders :: CollectPass p => CollectFlag p -> LHsBindsLR p idR -> [IdP p] collectHsBindsBinders flag binds = collect_binds False flag binds [] collectHsBindListBinders :: forall p idR. CollectPass p => CollectFlag p -> [LHsBindLR p idR] -> [IdP p] -- ^ Same as 'collectHsBindsBinders', but works over a list of bindings collectHsBindListBinders flag = foldr (collect_bind False flag . unXRec @p) [] collect_hs_val_binders :: CollectPass (GhcPass idL) => Bool -> CollectFlag (GhcPass idL) -> HsValBindsLR (GhcPass idL) idR -> [IdP (GhcPass idL)] collect_hs_val_binders ps flag = \case ValBinds _ binds _ -> collect_binds ps flag binds [] XValBindsLR (NValBinds binds _) -> collect_out_binds ps flag binds collect_out_binds :: forall p. CollectPass p => Bool -> CollectFlag p -> [(RecFlag, LHsBinds p)] -> [IdP p] collect_out_binds ps flag = foldr (collect_binds ps flag . snd) [] collect_binds :: forall p idR. CollectPass p => Bool -> CollectFlag p -> LHsBindsLR p idR -> [IdP p] -> [IdP p] -- ^ Collect 'Id's, or 'Id's + pattern synonyms, depending on boolean flag collect_binds ps flag binds acc = foldr (collect_bind ps flag . unXRec @p) acc binds collect_bind :: forall p idR. CollectPass p => Bool -> CollectFlag p -> HsBindLR p idR -> [IdP p] -> [IdP p] collect_bind _ _ (FunBind { fun_id = f }) acc = unXRec @p f : acc collect_bind _ flag (PatBind { pat_lhs = p }) acc = collect_lpat flag p acc collect_bind _ _ (VarBind { var_id = f }) acc = f : acc collect_bind omitPatSyn _ (PatSynBind _ (PSB { psb_id = ps })) acc | omitPatSyn = acc | otherwise = unXRec @p ps : acc collect_bind _ _ (PatSynBind _ (XPatSynBind _)) acc = acc collect_bind _ _ (XHsBindsLR b) acc = collectXXHsBindsLR @p @idR b acc collectMethodBinders :: forall idL idR. UnXRec idL => LHsBindsLR idL idR -> [LIdP idL] -- ^ Used exclusively for the bindings of an instance decl which are all -- 'FunBinds' collectMethodBinders binds = foldr (get . unXRec @idL) [] binds where get (FunBind { fun_id = f }) fs = f : fs get _ fs = fs -- Someone else complains about non-FunBinds ----------------- Statements -------------------------- -- collectLStmtsBinders :: CollectPass (GhcPass idL) => CollectFlag (GhcPass idL) -> [LStmtLR (GhcPass idL) (GhcPass idR) body] -> [IdP (GhcPass idL)] collectLStmtsBinders flag = concatMap (collectLStmtBinders flag) collectStmtsBinders :: CollectPass (GhcPass idL) => CollectFlag (GhcPass idL) -> [StmtLR (GhcPass idL) (GhcPass idR) body] -> [IdP (GhcPass idL)] collectStmtsBinders flag = concatMap (collectStmtBinders flag) collectLStmtBinders :: CollectPass (GhcPass idL) => CollectFlag (GhcPass idL) -> LStmtLR (GhcPass idL) (GhcPass idR) body -> [IdP (GhcPass idL)] collectLStmtBinders flag = collectStmtBinders flag . unLoc collectStmtBinders :: CollectPass (GhcPass idL) => CollectFlag (GhcPass idL) -> StmtLR (GhcPass idL) (GhcPass idR) body -> [IdP (GhcPass idL)] -- Id Binders for a Stmt... [but what about pattern-sig type vars]? collectStmtBinders flag = \case BindStmt _ pat _ -> collectPatBinders flag pat LetStmt _ binds -> collectLocalBinders flag binds BodyStmt {} -> [] LastStmt {} -> [] ParStmt _ xs _ _ -> collectLStmtsBinders flag [s | ParStmtBlock _ ss _ _ <- xs, s <- ss] TransStmt { trS_stmts = stmts } -> collectLStmtsBinders flag stmts RecStmt { recS_stmts = L _ ss } -> collectLStmtsBinders flag ss ApplicativeStmt _ args _ -> concatMap collectArgBinders args where collectArgBinders = \case (_, ApplicativeArgOne { app_arg_pattern = pat }) -> collectPatBinders flag pat (_, ApplicativeArgMany { bv_pattern = pat }) -> collectPatBinders flag pat ----------------- Patterns -------------------------- collectPatBinders :: CollectPass p => CollectFlag p -> LPat p -> [IdP p] collectPatBinders flag pat = collect_lpat flag pat [] collectPatsBinders :: CollectPass p => CollectFlag p -> [LPat p] -> [IdP p] collectPatsBinders flag pats = foldr (collect_lpat flag) [] pats ------------- -- | Indicate if evidence binders have to be collected. -- -- This type is used as a boolean (should we collect evidence binders or not?) -- but also to pass an evidence that the AST has been typechecked when we do -- want to collect evidence binders, otherwise these binders are not available. -- -- See Note [Dictionary binders in ConPatOut] data CollectFlag p where -- | Don't collect evidence binders CollNoDictBinders :: CollectFlag p -- | Collect evidence binders CollWithDictBinders :: CollectFlag GhcTc collect_lpat :: forall p. CollectPass p => CollectFlag p -> LPat p -> [IdP p] -> [IdP p] collect_lpat flag pat bndrs = collect_pat flag (unXRec @p pat) bndrs collect_pat :: forall p. CollectPass p => CollectFlag p -> Pat p -> [IdP p] -> [IdP p] collect_pat flag pat bndrs = case pat of VarPat _ var -> unXRec @p var : bndrs WildPat _ -> bndrs LazyPat _ pat -> collect_lpat flag pat bndrs BangPat _ pat -> collect_lpat flag pat bndrs AsPat _ a pat -> unXRec @p a : collect_lpat flag pat bndrs ViewPat _ _ pat -> collect_lpat flag pat bndrs ParPat _ _ pat _ -> collect_lpat flag pat bndrs ListPat _ pats -> foldr (collect_lpat flag) bndrs pats TuplePat _ pats _ -> foldr (collect_lpat flag) bndrs pats SumPat _ pat _ _ -> collect_lpat flag pat bndrs LitPat _ _ -> bndrs NPat {} -> bndrs NPlusKPat _ n _ _ _ _ -> unXRec @p n : bndrs SigPat _ pat _ -> collect_lpat flag pat bndrs XPat ext -> collectXXPat @p flag ext bndrs SplicePat _ (HsSpliced _ _ (HsSplicedPat pat)) -> collect_pat flag pat bndrs SplicePat _ _ -> bndrs -- See Note [Dictionary binders in ConPatOut] ConPat {pat_args=ps} -> case flag of CollNoDictBinders -> foldr (collect_lpat flag) bndrs (hsConPatArgs ps) CollWithDictBinders -> foldr (collect_lpat flag) bndrs (hsConPatArgs ps) ++ collectEvBinders (cpt_binds (pat_con_ext pat)) collectEvBinders :: TcEvBinds -> [Id] collectEvBinders (EvBinds bs) = foldr add_ev_bndr [] bs collectEvBinders (TcEvBinds {}) = panic "ToDo: collectEvBinders" add_ev_bndr :: EvBind -> [Id] -> [Id] add_ev_bndr (EvBind { eb_lhs = b }) bs | isId b = b:bs | otherwise = bs -- A worry: what about coercion variable binders?? -- | This class specifies how to collect variable identifiers from extension patterns in the given pass. -- Consumers of the GHC API that define their own passes should feel free to implement instances in order -- to make use of functions which depend on it. -- -- In particular, Haddock already makes use of this, with an instance for its 'DocNameI' pass so that -- it can reuse the code in GHC for collecting binders. class UnXRec p => CollectPass p where collectXXPat :: CollectFlag p -> XXPat p -> [IdP p] -> [IdP p] collectXXHsBindsLR :: forall pR. XXHsBindsLR p pR -> [IdP p] -> [IdP p] instance IsPass p => CollectPass (GhcPass p) where collectXXPat flag ext = case ghcPass @p of GhcPs -> dataConCantHappen ext GhcRn | HsPatExpanded _ pat <- ext -> collect_pat flag pat GhcTc -> case ext of CoPat _ pat _ -> collect_pat flag pat ExpansionPat _ pat -> collect_pat flag pat collectXXHsBindsLR ext = case ghcPass @p of GhcPs -> dataConCantHappen ext GhcRn -> dataConCantHappen ext GhcTc -> case ext of AbsBinds { abs_exports = dbinds } -> (map abe_poly dbinds ++) -- I don't think we want the binders from the abe_binds -- binding (hence see AbsBinds) is in zonking in GHC.Tc.Utils.Zonk {- Note [Dictionary binders in ConPatOut] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Should we collect dictionary binders in ConPatOut? It depends! Use CollectFlag to choose. 1. Pre-typechecker there are no ConPatOuts. Use CollNoDictBinders flag. 2. In the desugarer, most of the time we don't want to collect evidence binders, so we also use CollNoDictBinders flag. Example of why it matters: In a lazy pattern, for example f ~(C x y) = ..., we want to generate bindings for x,y but not for dictionaries bound by C. (The type checker ensures they would not be used.) Here's the problem. Consider data T a where C :: Num a => a -> Int -> T a f ~(C (n+1) m) = (n,m) Here, the pattern (C (n+1)) binds a hidden dictionary (d::Num a), and *also* uses that dictionary to match the (n+1) pattern. Yet, the variables bound by the lazy pattern are n,m, *not* the dictionary d. So in mkSelectorBinds in GHC.HsToCore.Utils, we want just m,n as the variables bound. So in this case, we do *not* gather (a) dictionary and (b) dictionary bindings as binders of a ConPatOut pattern. 3. On the other hand, desugaring of arrows needs evidence bindings and uses CollWithDictBinders flag. Consider h :: (ArrowChoice a, Arrow a) => Int -> a (Int,Int) Int h x = proc (y,z) -> case compare x y of GT -> returnA -< z+x The type checker turns the case into case compare x y of GT { $dNum_123 = $dNum_Int } -> returnA -< (+) $dNum_123 z x That is, it attaches the $dNum_123 binding to a ConPatOut in scope. During desugaring, evidence binders must be collected because their sets are intersected with free variable sets of subsequent commands to create (minimal) command environments. Failing to do it properly leads to bugs (e.g., #18950). Note: attaching evidence binders to existing ConPatOut may be suboptimal for arrows. In the example above we would prefer to generate: case compare x y of GT -> returnA -< let $dNum_123 = $dNum_Int in (+) $dNum_123 z x So that the evidence isn't passed into the command environment. This issue doesn't arise with desugaring of non-arrow code because the simplifier can freely float and inline let-expressions created for evidence binders. But with arrow desugaring, the simplifier would have to see through the command environment tuple which is more complicated. -} hsGroupBinders :: HsGroup GhcRn -> [Name] hsGroupBinders (HsGroup { hs_valds = val_decls, hs_tyclds = tycl_decls, hs_fords = foreign_decls }) = collectHsValBinders CollNoDictBinders val_decls ++ hsTyClForeignBinders tycl_decls foreign_decls hsTyClForeignBinders :: [TyClGroup GhcRn] -> [LForeignDecl GhcRn] -> [Name] -- We need to look at instance declarations too, -- because their associated types may bind data constructors hsTyClForeignBinders tycl_decls foreign_decls = map unLoc (hsForeignDeclsBinders foreign_decls) ++ getSelectorNames (foldMap (foldMap hsLTyClDeclBinders . group_tyclds) tycl_decls `mappend` foldMap (foldMap hsLInstDeclBinders . group_instds) tycl_decls) where getSelectorNames :: ([LocatedA Name], [LFieldOcc GhcRn]) -> [Name] getSelectorNames (ns, fs) = map unLoc ns ++ map (foExt . unLoc) fs ------------------- hsLTyClDeclBinders :: IsPass p => LocatedA (TyClDecl (GhcPass p)) -> ([LocatedA (IdP (GhcPass p))], [LFieldOcc (GhcPass p)]) -- ^ Returns all the /binding/ names of the decl. The first one is -- guaranteed to be the name of the decl. The first component -- represents all binding names except record fields; the second -- represents field occurrences. For record fields mentioned in -- multiple constructors, the SrcLoc will be from the first occurrence. -- -- Each returned (Located name) has a SrcSpan for the /whole/ declaration. -- See Note [SrcSpan for binders] hsLTyClDeclBinders (L loc (FamDecl { tcdFam = FamilyDecl { fdLName = (L _ name) } })) = ([L loc name], []) hsLTyClDeclBinders (L loc (SynDecl { tcdLName = (L _ name) })) = ([L loc name], []) hsLTyClDeclBinders (L loc (ClassDecl { tcdLName = (L _ cls_name) , tcdSigs = sigs , tcdATs = ats })) = (L loc cls_name : [ L fam_loc fam_name | (L fam_loc (FamilyDecl { fdLName = L _ fam_name })) <- ats ] ++ [ L mem_loc mem_name | (L mem_loc (ClassOpSig _ False ns _)) <- sigs , (L _ mem_name) <- ns ] , []) hsLTyClDeclBinders (L loc (DataDecl { tcdLName = (L _ name) , tcdDataDefn = defn })) = (\ (xs, ys) -> (L loc name : xs, ys)) $ hsDataDefnBinders defn ------------------- hsForeignDeclsBinders :: forall p a. (UnXRec (GhcPass p), IsSrcSpanAnn p a) => [LForeignDecl (GhcPass p)] -> [LIdP (GhcPass p)] -- ^ See Note [SrcSpan for binders] hsForeignDeclsBinders foreign_decls = [ L (noAnnSrcSpan (locA decl_loc)) n | L decl_loc (ForeignImport { fd_name = L _ n }) <- foreign_decls] ------------------- hsPatSynSelectors :: IsPass p => HsValBinds (GhcPass p) -> [FieldOcc (GhcPass p)] -- ^ Collects record pattern-synonym selectors only; the pattern synonym -- names are collected by 'collectHsValBinders'. hsPatSynSelectors (ValBinds _ _ _) = panic "hsPatSynSelectors" hsPatSynSelectors (XValBindsLR (NValBinds binds _)) = foldr addPatSynSelector [] . unionManyBags $ map snd binds addPatSynSelector :: forall p. UnXRec p => LHsBind p -> [FieldOcc p] -> [FieldOcc p] addPatSynSelector bind sels | PatSynBind _ (PSB { psb_args = RecCon as }) <- unXRec @p bind = map recordPatSynField as ++ sels | otherwise = sels getPatSynBinds :: forall id. UnXRec id => [(RecFlag, LHsBinds id)] -> [PatSynBind id id] getPatSynBinds binds = [ psb | (_, lbinds) <- binds , (unXRec @id -> (PatSynBind _ psb)) <- bagToList lbinds ] ------------------- hsLInstDeclBinders :: IsPass p => LInstDecl (GhcPass p) -> ([LocatedA (IdP (GhcPass p))], [LFieldOcc (GhcPass p)]) hsLInstDeclBinders (L _ (ClsInstD { cid_inst = ClsInstDecl { cid_datafam_insts = dfis }})) = foldMap (hsDataFamInstBinders . unLoc) dfis hsLInstDeclBinders (L _ (DataFamInstD { dfid_inst = fi })) = hsDataFamInstBinders fi hsLInstDeclBinders (L _ (TyFamInstD {})) = mempty ------------------- -- | the 'SrcLoc' returned are for the whole declarations, not just the names hsDataFamInstBinders :: IsPass p => DataFamInstDecl (GhcPass p) -> ([LocatedA (IdP (GhcPass p))], [LFieldOcc (GhcPass p)]) hsDataFamInstBinders (DataFamInstDecl { dfid_eqn = FamEqn { feqn_rhs = defn }}) = hsDataDefnBinders defn -- There can't be repeated symbols because only data instances have binders ------------------- -- | the 'SrcLoc' returned are for the whole declarations, not just the names hsDataDefnBinders :: IsPass p => HsDataDefn (GhcPass p) -> ([LocatedA (IdP (GhcPass p))], [LFieldOcc (GhcPass p)]) hsDataDefnBinders (HsDataDefn { dd_cons = cons }) = hsConDeclsBinders cons -- See Note [Binders in family instances] ------------------- type Seen p = [LFieldOcc (GhcPass p)] -> [LFieldOcc (GhcPass p)] -- Filters out ones that have already been seen hsConDeclsBinders :: forall p. IsPass p => [LConDecl (GhcPass p)] -> ([LocatedA (IdP (GhcPass p))], [LFieldOcc (GhcPass p)]) -- See hsLTyClDeclBinders for what this does -- The function is boringly complicated because of the records -- And since we only have equality, we have to be a little careful hsConDeclsBinders cons = go id cons where go :: Seen p -> [LConDecl (GhcPass p)] -> ([LocatedA (IdP (GhcPass p))], [LFieldOcc (GhcPass p)]) go _ [] = ([], []) go remSeen (r:rs) -- Don't re-mangle the location of field names, because we don't -- have a record of the full location of the field declaration anyway = let loc = getLoc r in case unLoc r of -- remove only the first occurrence of any seen field in order to -- avoid circumventing detection of duplicate fields (#9156) ConDeclGADT { con_names = names, con_g_args = args } -> (map (L loc . unLoc) names ++ ns, flds ++ fs) where (remSeen', flds) = get_flds_gadt remSeen args (ns, fs) = go remSeen' rs ConDeclH98 { con_name = name, con_args = args } -> ([L loc (unLoc name)] ++ ns, flds ++ fs) where (remSeen', flds) = get_flds_h98 remSeen args (ns, fs) = go remSeen' rs get_flds_h98 :: Seen p -> HsConDeclH98Details (GhcPass p) -> (Seen p, [LFieldOcc (GhcPass p)]) get_flds_h98 remSeen (RecCon flds) = get_flds remSeen flds get_flds_h98 remSeen _ = (remSeen, []) get_flds_gadt :: Seen p -> HsConDeclGADTDetails (GhcPass p) -> (Seen p, [LFieldOcc (GhcPass p)]) get_flds_gadt remSeen (RecConGADT flds _) = get_flds remSeen flds get_flds_gadt remSeen _ = (remSeen, []) get_flds :: Seen p -> LocatedL [LConDeclField (GhcPass p)] -> (Seen p, [LFieldOcc (GhcPass p)]) get_flds remSeen flds = (remSeen', fld_names) where fld_names = remSeen (concatMap (cd_fld_names . unLoc) (unLoc flds)) remSeen' = foldr (.) remSeen [deleteBy ((==) `on` unLoc . foLabel . unLoc) v | v <- fld_names] {- Note [SrcSpan for binders] ~~~~~~~~~~~~~~~~~~~~~~~~~~ When extracting the (Located RdrNme) for a binder, at least for the main name (the TyCon of a type declaration etc), we want to give it the @SrcSpan@ of the whole /declaration/, not just the name itself (which is how it appears in the syntax tree). This SrcSpan (for the entire declaration) is used as the SrcSpan for the Name that is finally produced, and hence for error messages. (See #8607.) Note [Binders in family instances] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In a type or data family instance declaration, the type constructor is an *occurrence* not a binding site type instance T Int = Int -> Int -- No binders data instance S Bool = S1 | S2 -- Binders are S1,S2 ************************************************************************ * * Collecting binders the user did not write * * ************************************************************************ The job of this family of functions is to run through binding sites and find the set of all Names that were defined "implicitly", without being explicitly written by the user. The main purpose is to find names introduced by record wildcards so that we can avoid warning the user when they don't use those names (#4404) Since the addition of -Wunused-record-wildcards, this function returns a pair of [(SrcSpan, [Name])]. Each element of the list is one set of implicit binders, the first component of the tuple is the document describes the possible fix to the problem (by removing the ..). This means there is some unfortunate coupling between this function and where it is used but it's only used for one specific purpose in one place so it seemed easier. -} lStmtsImplicits :: [LStmtLR GhcRn (GhcPass idR) (LocatedA (body (GhcPass idR)))] -> [(SrcSpan, [Name])] lStmtsImplicits = hs_lstmts where hs_lstmts :: [LStmtLR GhcRn (GhcPass idR) (LocatedA (body (GhcPass idR)))] -> [(SrcSpan, [Name])] hs_lstmts = concatMap (hs_stmt . unLoc) hs_stmt :: StmtLR GhcRn (GhcPass idR) (LocatedA (body (GhcPass idR))) -> [(SrcSpan, [Name])] hs_stmt (BindStmt _ pat _) = lPatImplicits pat hs_stmt (ApplicativeStmt _ args _) = concatMap do_arg args where do_arg (_, ApplicativeArgOne { app_arg_pattern = pat }) = lPatImplicits pat do_arg (_, ApplicativeArgMany { app_stmts = stmts }) = hs_lstmts stmts hs_stmt (LetStmt _ binds) = hs_local_binds binds hs_stmt (BodyStmt {}) = [] hs_stmt (LastStmt {}) = [] hs_stmt (ParStmt _ xs _ _) = hs_lstmts [s | ParStmtBlock _ ss _ _ <- xs , s <- ss] hs_stmt (TransStmt { trS_stmts = stmts }) = hs_lstmts stmts hs_stmt (RecStmt { recS_stmts = L _ ss }) = hs_lstmts ss hs_local_binds (HsValBinds _ val_binds) = hsValBindsImplicits val_binds hs_local_binds (HsIPBinds {}) = [] hs_local_binds (EmptyLocalBinds _) = [] hsValBindsImplicits :: HsValBindsLR GhcRn (GhcPass idR) -> [(SrcSpan, [Name])] hsValBindsImplicits (XValBindsLR (NValBinds binds _)) = concatMap (lhsBindsImplicits . snd) binds hsValBindsImplicits (ValBinds _ binds _) = lhsBindsImplicits binds lhsBindsImplicits :: LHsBindsLR GhcRn idR -> [(SrcSpan, [Name])] lhsBindsImplicits = foldBag (++) (lhs_bind . unLoc) [] where lhs_bind (PatBind { pat_lhs = lpat }) = lPatImplicits lpat lhs_bind _ = [] lPatImplicits :: LPat GhcRn -> [(SrcSpan, [Name])] lPatImplicits = hs_lpat where hs_lpat lpat = hs_pat (unLoc lpat) hs_lpats = foldr (\pat rest -> hs_lpat pat ++ rest) [] hs_pat (LazyPat _ pat) = hs_lpat pat hs_pat (BangPat _ pat) = hs_lpat pat hs_pat (AsPat _ _ pat) = hs_lpat pat hs_pat (ViewPat _ _ pat) = hs_lpat pat hs_pat (ParPat _ _ pat _) = hs_lpat pat hs_pat (ListPat _ pats) = hs_lpats pats hs_pat (TuplePat _ pats _) = hs_lpats pats hs_pat (SigPat _ pat _) = hs_lpat pat hs_pat (ConPat {pat_con=con, pat_args=ps}) = details con ps hs_pat _ = [] details :: LocatedN Name -> HsConPatDetails GhcRn -> [(SrcSpan, [Name])] details _ (PrefixCon _ ps) = hs_lpats ps details n (RecCon fs) = [(err_loc, collectPatsBinders CollNoDictBinders implicit_pats) | Just{} <- [rec_dotdot fs] ] ++ hs_lpats explicit_pats where implicit_pats = map (hfbRHS . unLoc) implicit explicit_pats = map (hfbRHS . unLoc) explicit (explicit, implicit) = partitionEithers [if pat_explicit then Left fld else Right fld | (i, fld) <- [0..] `zip` rec_flds fs , let pat_explicit = maybe True ((i<) . unLoc) (rec_dotdot fs)] err_loc = maybe (getLocA n) getLoc (rec_dotdot fs) details _ (InfixCon p1 p2) = hs_lpat p1 ++ hs_lpat p2