{-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE TypeFamilies #-} {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-} {- This module contains miscellaneous functions related to renaming. -} module GHC.Rename.Utils ( checkDupRdrNames, checkDupRdrNamesN, checkShadowedRdrNames, checkDupNames, checkDupAndShadowedNames, dupNamesErr, checkTupSize, checkCTupSize, addFvRn, mapFvRn, mapMaybeFvRn, warnUnusedMatches, warnUnusedTypePatterns, warnUnusedTopBinds, warnUnusedLocalBinds, warnForallIdentifier, checkUnusedRecordWildcard, mkFieldEnv, badQualBndrErr, typeAppErr, badFieldConErr, wrapGenSpan, genHsVar, genLHsVar, genHsApp, genHsApps, genAppType, genHsIntegralLit, genHsTyLit, newLocalBndrRn, newLocalBndrsRn, bindLocalNames, bindLocalNamesFV, addNameClashErrRn, checkInferredVars, noNestedForallsContextsErr, addNoNestedForallsContextsErr ) where import GHC.Prelude import GHC.Core.Type import GHC.Hs import GHC.Types.Name.Reader import GHC.Tc.Errors.Types import GHC.Tc.Errors.Ppr (withHsDocContext) import GHC.Tc.Utils.Env import GHC.Tc.Utils.Monad import GHC.Types.Error import GHC.Types.Name import GHC.Types.Name.Set import GHC.Types.Name.Env import GHC.Core.DataCon import GHC.Types.SrcLoc as SrcLoc import GHC.Types.SourceFile import GHC.Types.SourceText ( SourceText(..), IntegralLit ) import GHC.Utils.Outputable import GHC.Utils.Panic import GHC.Utils.Misc import GHC.Types.Basic ( TopLevelFlag(..) ) import GHC.Data.List.SetOps ( removeDups ) import GHC.Data.Maybe ( whenIsJust ) import GHC.Driver.Session import GHC.Data.FastString import Control.Monad import Data.List (find, sortBy) import GHC.Settings.Constants ( mAX_TUPLE_SIZE, mAX_CTUPLE_SIZE ) import qualified Data.List.NonEmpty as NE import qualified GHC.LanguageExtensions as LangExt import GHC.Data.Bag {- ********************************************************* * * \subsection{Binding} * * ********************************************************* -} newLocalBndrRn :: LocatedN RdrName -> RnM Name -- Used for non-top-level binders. These should -- never be qualified. newLocalBndrRn (L loc rdr_name) | Just name <- isExact_maybe rdr_name = return name -- This happens in code generated by Template Haskell -- See Note [Binders in Template Haskell] in "GHC.ThToHs" | otherwise = do { unless (isUnqual rdr_name) (addErrAt (locA loc) (badQualBndrErr rdr_name)) ; uniq <- newUnique ; return (mkInternalName uniq (rdrNameOcc rdr_name) (locA loc)) } newLocalBndrsRn :: [LocatedN RdrName] -> RnM [Name] newLocalBndrsRn = mapM newLocalBndrRn bindLocalNames :: [Name] -> RnM a -> RnM a bindLocalNames names = updLclEnv $ \ lcl_env -> let th_level = thLevel (tcl_th_ctxt lcl_env) th_bndrs' = extendNameEnvList (tcl_th_bndrs lcl_env) [ (n, (NotTopLevel, th_level)) | n <- names ] rdr_env' = extendLocalRdrEnvList (tcl_rdr lcl_env) names in lcl_env { tcl_th_bndrs = th_bndrs' , tcl_rdr = rdr_env' } bindLocalNamesFV :: [Name] -> RnM (a, FreeVars) -> RnM (a, FreeVars) bindLocalNamesFV names enclosed_scope = do { (result, fvs) <- bindLocalNames names enclosed_scope ; return (result, delFVs names fvs) } ------------------------------------- checkDupRdrNames :: [LocatedN RdrName] -> RnM () -- Check for duplicated names in a binding group checkDupRdrNames rdr_names_w_loc = mapM_ (dupNamesErr getLocA) dups where (_, dups) = removeDups (\n1 n2 -> unLoc n1 `compare` unLoc n2) rdr_names_w_loc checkDupRdrNamesN :: [LocatedN RdrName] -> RnM () -- Check for duplicated names in a binding group checkDupRdrNamesN rdr_names_w_loc = mapM_ (dupNamesErr getLocA) dups where (_, dups) = removeDups (\n1 n2 -> unLoc n1 `compare` unLoc n2) rdr_names_w_loc checkDupNames :: [Name] -> RnM () -- Check for duplicated names in a binding group checkDupNames names = check_dup_names (filterOut isSystemName names) -- See Note [Binders in Template Haskell] in "GHC.ThToHs" check_dup_names :: [Name] -> RnM () check_dup_names names = mapM_ (dupNamesErr nameSrcSpan) dups where (_, dups) = removeDups (\n1 n2 -> nameOccName n1 `compare` nameOccName n2) names --------------------- checkShadowedRdrNames :: [LocatedN RdrName] -> RnM () checkShadowedRdrNames loc_rdr_names = do { envs <- getRdrEnvs ; checkShadowedOccs envs get_loc_occ filtered_rdrs } where filtered_rdrs = filterOut (isExact . unLoc) loc_rdr_names -- See Note [Binders in Template Haskell] in "GHC.ThToHs" get_loc_occ (L loc rdr) = (locA loc,rdrNameOcc rdr) checkDupAndShadowedNames :: (GlobalRdrEnv, LocalRdrEnv) -> [Name] -> RnM () checkDupAndShadowedNames envs names = do { check_dup_names filtered_names ; checkShadowedOccs envs get_loc_occ filtered_names } where filtered_names = filterOut isSystemName names -- See Note [Binders in Template Haskell] in "GHC.ThToHs" get_loc_occ name = (nameSrcSpan name, nameOccName name) ------------------------------------- checkShadowedOccs :: (GlobalRdrEnv, LocalRdrEnv) -> (a -> (SrcSpan, OccName)) -> [a] -> RnM () checkShadowedOccs (global_env,local_env) get_loc_occ ns = whenWOptM Opt_WarnNameShadowing $ do { traceRn "checkShadowedOccs:shadow" (ppr (map get_loc_occ ns)) ; mapM_ check_shadow ns } where check_shadow n | startsWithUnderscore occ = return () -- Do not report shadowing for "_x" -- See #3262 | Just n <- mb_local = complain (ShadowedNameProvenanceLocal (nameSrcLoc n)) | otherwise = do { gres' <- filterM is_shadowed_gre gres ; when (not . null $ gres') $ complain (ShadowedNameProvenanceGlobal gres') } where (loc,occ) = get_loc_occ n mb_local = lookupLocalRdrOcc local_env occ gres = lookupGRE_RdrName (mkRdrUnqual occ) global_env -- Make an Unqualified RdrName and look that up, so that -- we don't find any GREs that are in scope qualified-only complain provenance = addDiagnosticAt loc (TcRnShadowedName occ provenance) is_shadowed_gre :: GlobalRdrElt -> RnM Bool -- Returns False for record selectors that are shadowed, when -- punning or wild-cards are on (cf #2723) is_shadowed_gre gre | isRecFldGRE gre = do { dflags <- getDynFlags ; return $ not (xopt LangExt.NamedFieldPuns dflags || xopt LangExt.RecordWildCards dflags) } is_shadowed_gre _other = return True ------------------------------------- -- | Throw an error message if a user attempts to quantify an inferred type -- variable in a place where specificity cannot be observed. For example, -- @forall {a}. [a] -> [a]@ would be rejected to the inferred type variable -- @{a}@, but @forall a. [a] -> [a]@ would be accepted. -- See @Note [Unobservably inferred type variables]@. checkInferredVars :: HsDocContext -> Maybe SDoc -- ^ The error msg if the signature is not allowed to contain -- manually written inferred variables. -> LHsSigType GhcPs -> RnM () checkInferredVars _ Nothing _ = return () checkInferredVars ctxt (Just msg) ty = let bndrs = sig_ty_bndrs ty in case find ((==) InferredSpec . hsTyVarBndrFlag) bndrs of Nothing -> return () Just _ -> addErr $ TcRnUnknownMessage $ mkPlainError noHints (withHsDocContext ctxt msg) where sig_ty_bndrs :: LHsSigType GhcPs -> [HsTyVarBndr Specificity GhcPs] sig_ty_bndrs (L _ (HsSig{sig_bndrs = outer_bndrs})) = map unLoc (hsOuterExplicitBndrs outer_bndrs) {- Note [Unobservably inferred type variables] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ While GHC's parser allows the use of inferred type variables (e.g., `forall {a}. <...>`) just about anywhere that type variable binders can appear, there are some situations where the distinction between inferred and specified type variables cannot be observed. For example, consider this instance declaration: instance forall {a}. Eq (T a) where ... Making {a} inferred is pointless, as there is no way for user code to "apply" an instance declaration in a way where the inferred/specified distinction would make a difference. (Notably, there is no opportunity for visible type application of an instance declaration.) Anyone who writes such code is likely confused, so in an attempt to be helpful, we emit an error message if a user writes code like this. The checkInferredVars function is responsible for implementing this restriction. It turns out to be somewhat cumbersome to enforce this restriction in certain cases. Specifically: * Quantified constraints. In the type `f :: (forall {a}. C a) => Proxy Int`, there is no way to observe that {a} is inferred. Nevertheless, actually rejecting this code would be tricky, as we would need to reject `forall {a}. <...>` as a constraint but *accept* other uses of `forall {a}. <...>` as a type (e.g., `g :: (forall {a}. a -> a) -> b -> b`). This is quite tedious to do in practice, so we don't bother. * Default method type signatures (#18432). These are tricky because inferred type variables can appear nested, e.g., class C a where m :: forall b. a -> b -> forall c. c -> c default m :: forall b. a -> b -> forall {c}. c -> c m _ _ = id Robustly checking for nested, inferred type variables ends up being a pain, so we don't try to do this. For now, we simply allow inferred quantifiers to be specified here, even though doing so is pointless. All we lose is a warning. Aside from the places where we already use checkInferredVars, most of the other places where inferred vars don't make sense are in any case already prohibited from having foralls /at all/. For example: instance forall a. forall {b}. Eq (Either a b) where ... Here the nested `forall {b}` is already prohibited. (See Note [No nested foralls or contexts in instance types] in GHC.Hs.Type). -} -- | Examines a non-outermost type for @forall@s or contexts, which are assumed -- to be nested. For example, in the following declaration: -- -- @ -- instance forall a. forall b. C (Either a b) -- @ -- -- The outermost @forall a@ is fine, but the nested @forall b@ is not. We -- invoke 'noNestedForallsContextsErr' on the type @forall b. C (Either a b)@ -- to catch the nested @forall@ and create a suitable error message. -- 'noNestedForallsContextsErr' returns @'Just' err_msg@ if such a @forall@ or -- context is found, and returns @Nothing@ otherwise. -- -- This is currently used in the following places: -- -- * In GADT constructor types (in 'rnConDecl'). -- See @Note [GADT abstract syntax] (Wrinkle: No nested foralls or contexts)@ -- in "GHC.Hs.Type". -- -- * In instance declaration types (in 'rnClsIntDecl' and 'rnSrcDerivDecl' in -- "GHC.Rename.Module" and 'renameSig' in "GHC.Rename.Bind"). -- See @Note [No nested foralls or contexts in instance types]@ in -- "GHC.Hs.Type". noNestedForallsContextsErr :: SDoc -> LHsType GhcRn -> Maybe (SrcSpan, SDoc) noNestedForallsContextsErr what lty = case ignoreParens lty of L l (HsForAllTy { hst_tele = tele }) | HsForAllVis{} <- tele -- The only two places where this function is called correspond to -- types of terms, so we give a slightly more descriptive error -- message in the event that they contain visible dependent -- quantification (currently only allowed in kinds). -> Just (locA l, vcat [ text "Illegal visible, dependent quantification" <+> text "in the type of a term" , text "(GHC does not yet support this)" ]) | HsForAllInvis{} <- tele -> Just (locA l, nested_foralls_contexts_err) L l (HsQualTy {}) -> Just (locA l, nested_foralls_contexts_err) _ -> Nothing where nested_foralls_contexts_err = what <+> text "cannot contain nested" <+> quotes forAllLit <> text "s or contexts" -- | A common way to invoke 'noNestedForallsContextsErr'. addNoNestedForallsContextsErr :: HsDocContext -> SDoc -> LHsType GhcRn -> RnM () addNoNestedForallsContextsErr ctxt what lty = whenIsJust (noNestedForallsContextsErr what lty) $ \(l, err_msg) -> addErrAt l $ TcRnUnknownMessage $ mkPlainError noHints (withHsDocContext ctxt err_msg) {- ************************************************************************ * * \subsection{Free variable manipulation} * * ************************************************************************ -} -- A useful utility addFvRn :: FreeVars -> RnM (thing, FreeVars) -> RnM (thing, FreeVars) addFvRn fvs1 thing_inside = do { (res, fvs2) <- thing_inside ; return (res, fvs1 `plusFV` fvs2) } mapFvRn :: (a -> RnM (b, FreeVars)) -> [a] -> RnM ([b], FreeVars) mapFvRn f xs = do stuff <- mapM f xs case unzip stuff of (ys, fvs_s) -> return (ys, plusFVs fvs_s) mapMaybeFvRn :: (a -> RnM (b, FreeVars)) -> Maybe a -> RnM (Maybe b, FreeVars) mapMaybeFvRn _ Nothing = return (Nothing, emptyFVs) mapMaybeFvRn f (Just x) = do { (y, fvs) <- f x; return (Just y, fvs) } {- ************************************************************************ * * \subsection{Envt utility functions} * * ************************************************************************ -} warnUnusedTopBinds :: [GlobalRdrElt] -> RnM () warnUnusedTopBinds gres = whenWOptM Opt_WarnUnusedTopBinds $ do env <- getGblEnv let isBoot = tcg_src env == HsBootFile let noParent gre = case gre_par gre of NoParent -> True _ -> False -- Don't warn about unused bindings with parents in -- .hs-boot files, as you are sometimes required to give -- unused bindings (trac #3449). -- HOWEVER, in a signature file, you are never obligated to put a -- definition in the main text. Thus, if you define something -- and forget to export it, we really DO want to warn. gres' = if isBoot then filter noParent gres else gres warnUnusedGREs gres' -- | Checks to see if we need to warn for -Wunused-record-wildcards or -- -Wredundant-record-wildcards checkUnusedRecordWildcard :: SrcSpan -> FreeVars -> Maybe [Name] -> RnM () checkUnusedRecordWildcard _ _ Nothing = return () checkUnusedRecordWildcard loc _ (Just []) = -- Add a new warning if the .. pattern binds no variables setSrcSpan loc $ warnRedundantRecordWildcard checkUnusedRecordWildcard loc fvs (Just dotdot_names) = setSrcSpan loc $ warnUnusedRecordWildcard dotdot_names fvs -- | Produce a warning when the `..` pattern binds no new -- variables. -- -- @ -- data P = P { x :: Int } -- -- foo (P{x, ..}) = x -- @ -- -- The `..` here doesn't bind any variables as `x` is already bound. warnRedundantRecordWildcard :: RnM () warnRedundantRecordWildcard = whenWOptM Opt_WarnRedundantRecordWildcards $ let msg = TcRnUnknownMessage $ mkPlainDiagnostic (WarningWithFlag Opt_WarnRedundantRecordWildcards) noHints redundantWildcardWarning in addDiagnostic msg -- | Produce a warning when no variables bound by a `..` pattern are used. -- -- @ -- data P = P { x :: Int } -- -- foo (P{..}) = () -- @ -- -- The `..` pattern binds `x` but it is not used in the RHS so we issue -- a warning. warnUnusedRecordWildcard :: [Name] -> FreeVars -> RnM () warnUnusedRecordWildcard ns used_names = do let used = filter (`elemNameSet` used_names) ns traceRn "warnUnused" (ppr ns $$ ppr used_names $$ ppr used) warnIf (null used) unusedRecordWildcardWarning warnUnusedLocalBinds, warnUnusedMatches, warnUnusedTypePatterns :: [Name] -> FreeVars -> RnM () warnUnusedLocalBinds = check_unused Opt_WarnUnusedLocalBinds warnUnusedMatches = check_unused Opt_WarnUnusedMatches warnUnusedTypePatterns = check_unused Opt_WarnUnusedTypePatterns check_unused :: WarningFlag -> [Name] -> FreeVars -> RnM () check_unused flag bound_names used_names = whenWOptM flag (warnUnused flag (filterOut (`elemNameSet` used_names) bound_names)) warnForallIdentifier :: LocatedN RdrName -> RnM () warnForallIdentifier (L l rdr_name@(Unqual occ)) | isKw (fsLit "forall") || isKw (fsLit "∀") = addDiagnosticAt (locA l) (TcRnForallIdentifier rdr_name) where isKw = (occNameFS occ ==) warnForallIdentifier _ = return () ------------------------- -- Helpers warnUnusedGREs :: [GlobalRdrElt] -> RnM () warnUnusedGREs gres = mapM_ warnUnusedGRE gres -- NB the Names must not be the names of record fields! warnUnused :: WarningFlag -> [Name] -> RnM () warnUnused flag names = mapM_ (warnUnused1 flag . NormalGreName) names warnUnused1 :: WarningFlag -> GreName -> RnM () warnUnused1 flag child = when (reportable child) $ addUnusedWarning flag (occName child) (greNameSrcSpan child) (text $ "Defined but not used" ++ opt_str) where opt_str = case flag of Opt_WarnUnusedTypePatterns -> " on the right hand side" _ -> "" warnUnusedGRE :: GlobalRdrElt -> RnM () warnUnusedGRE gre@(GRE { gre_lcl = lcl, gre_imp = is }) | lcl = warnUnused1 Opt_WarnUnusedTopBinds (gre_name gre) | otherwise = when (reportable (gre_name gre)) (mapM_ warn is) where occ = greOccName gre warn spec = addUnusedWarning Opt_WarnUnusedTopBinds occ span msg where span = importSpecLoc spec pp_mod = quotes (ppr (importSpecModule spec)) msg = text "Imported from" <+> pp_mod <+> text "but not used" -- | Make a map from selector names to field labels and parent tycon -- names, to be used when reporting unused record fields. mkFieldEnv :: GlobalRdrEnv -> NameEnv (FieldLabelString, Parent) mkFieldEnv rdr_env = mkNameEnv [ (greMangledName gre, (flLabel fl, gre_par gre)) | gres <- nonDetOccEnvElts rdr_env , gre <- gres , Just fl <- [greFieldLabel gre] ] -- | Should we report the fact that this 'Name' is unused? The -- 'OccName' may differ from 'nameOccName' due to -- DuplicateRecordFields. reportable :: GreName -> Bool reportable child | NormalGreName name <- child , isWiredInName name = False -- Don't report unused wired-in names -- Otherwise we get a zillion warnings -- from Data.Tuple | otherwise = not (startsWithUnderscore (occName child)) addUnusedWarning :: WarningFlag -> OccName -> SrcSpan -> SDoc -> RnM () addUnusedWarning flag occ span msg = do let diag = TcRnUnknownMessage $ mkPlainDiagnostic (WarningWithFlag flag) noHints $ sep [msg <> colon, nest 2 $ pprNonVarNameSpace (occNameSpace occ) <+> quotes (ppr occ)] addDiagnosticAt span diag unusedRecordWildcardWarning :: TcRnMessage unusedRecordWildcardWarning = TcRnUnknownMessage $ mkPlainDiagnostic (WarningWithFlag Opt_WarnUnusedRecordWildcards) noHints $ wildcardDoc $ text "No variables bound in the record wildcard match are used" redundantWildcardWarning :: SDoc redundantWildcardWarning = wildcardDoc $ text "Record wildcard does not bind any new variables" wildcardDoc :: SDoc -> SDoc wildcardDoc herald = herald $$ nest 2 (text "Possible fix" <> colon <+> text "omit the" <+> quotes (text "..")) {- Note [Skipping ambiguity errors at use sites of local declarations] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In general, we do not report ambiguous occurrences at use sites where all the clashing names are defined locally, because the error will have been reported at the definition site, and we want to avoid an error cascade. However, when DuplicateRecordFields is enabled, it is possible to define the same field name multiple times, so we *do* need to report an error at the use site when there is ambiguity between multiple fields. Moreover, when NoFieldSelectors is enabled, it is possible to define a field with the same name as a non-field, so again we need to report ambiguity at the use site. We can skip reporting an ambiguity error whenever defining the GREs must have yielded a duplicate declarations error. More precisely, we can skip if: * there are at least two non-fields amongst the GREs; or * there are at least two fields amongst the GREs, and DuplicateRecordFields is *disabled*; or * there is at least one non-field, at least one field, and NoFieldSelectors is *disabled*. These conditions ensure that a duplicate local declaration will have been reported. See also Note [Reporting duplicate local declarations] in GHC.Rename.Names). -} addNameClashErrRn :: RdrName -> NE.NonEmpty GlobalRdrElt -> RnM () addNameClashErrRn rdr_name gres | all isLocalGRE gres && can_skip -- If there are two or more *local* defns, we'll usually have reported that -- already, and we don't want an error cascade. = return () | otherwise = addErr $ TcRnUnknownMessage $ mkPlainError noHints $ (vcat [ text "Ambiguous occurrence" <+> quotes (ppr rdr_name) , text "It could refer to" , nest 3 (vcat (msg1 : msgs)) ]) where np1 NE.:| nps = gres msg1 = text "either" <+> ppr_gre np1 msgs = [text " or" <+> ppr_gre np | np <- nps] ppr_gre gre = sep [ pp_greMangledName gre <> comma , pprNameProvenance gre] -- When printing the name, take care to qualify it in the same -- way as the provenance reported by pprNameProvenance, namely -- the head of 'gre_imp'. Otherwise we get confusing reports like -- Ambiguous occurrence ‘null’ -- It could refer to either ‘T15487a.null’, -- imported from ‘Prelude’ at T15487.hs:1:8-13 -- or ... -- See #15487 pp_greMangledName gre@(GRE { gre_name = child, gre_par = par , gre_lcl = lcl, gre_imp = iss }) = case child of FieldGreName fl -> text "the field" <+> quotes (ppr fl) <+> parent_info NormalGreName name -> quotes (pp_qual name <> dot <> ppr (nameOccName name)) where parent_info = case par of NoParent -> empty ParentIs { par_is = par_name } -> text "of record" <+> quotes (ppr par_name) pp_qual name | lcl = ppr (nameModule name) | Just imp <- headMaybe iss -- This 'imp' is the one that -- pprNameProvenance chooses , ImpDeclSpec { is_as = mod } <- is_decl imp = ppr mod | otherwise = pprPanic "addNameClassErrRn" (ppr gre $$ ppr iss) -- Invariant: either 'lcl' is True or 'iss' is non-empty -- If all the GREs are defined locally, can we skip reporting an ambiguity -- error at use sites, because it will have been reported already? See -- Note [Skipping ambiguity errors at use sites of local declarations] can_skip = num_non_flds >= 2 || (num_flds >= 2 && not (isDuplicateRecFldGRE (head flds))) || (num_non_flds >= 1 && num_flds >= 1 && not (isNoFieldSelectorGRE (head flds))) (flds, non_flds) = NE.partition isRecFldGRE gres num_flds = length flds num_non_flds = length non_flds dupNamesErr :: Outputable n => (n -> SrcSpan) -> NE.NonEmpty n -> RnM () dupNamesErr get_loc names = addErrAt big_loc $ TcRnUnknownMessage $ mkPlainError noHints $ vcat [text "Conflicting definitions for" <+> quotes (ppr (NE.head names)), locations] where locs = map get_loc (NE.toList names) big_loc = foldr1 combineSrcSpans locs locations = text "Bound at:" <+> vcat (map ppr (sortBy SrcLoc.leftmost_smallest locs)) badQualBndrErr :: RdrName -> TcRnMessage badQualBndrErr rdr_name = TcRnUnknownMessage $ mkPlainError noHints $ text "Qualified name in binding position:" <+> ppr rdr_name typeAppErr :: String -> LHsType GhcPs -> TcRnMessage typeAppErr what (L _ k) = TcRnUnknownMessage $ mkPlainError noHints $ hang (text "Illegal visible" <+> text what <+> text "application" <+> quotes (char '@' <> ppr k)) 2 (text "Perhaps you intended to use TypeApplications") badFieldConErr :: Name -> FieldLabelString -> TcRnMessage badFieldConErr con field = TcRnUnknownMessage $ mkPlainError noHints $ hsep [text "Constructor" <+> quotes (ppr con), text "does not have field", quotes (ppr field)] -- | Ensure that a boxed or unboxed tuple has arity no larger than -- 'mAX_TUPLE_SIZE'. checkTupSize :: Int -> TcM () checkTupSize tup_size | tup_size <= mAX_TUPLE_SIZE = return () | otherwise = addErr $ TcRnUnknownMessage $ mkPlainError noHints $ sep [text "A" <+> int tup_size <> text "-tuple is too large for GHC", nest 2 (parens (text "max size is" <+> int mAX_TUPLE_SIZE)), nest 2 (text "Workaround: use nested tuples or define a data type")] -- | Ensure that a constraint tuple has arity no larger than 'mAX_CTUPLE_SIZE'. checkCTupSize :: Int -> TcM () checkCTupSize tup_size | tup_size <= mAX_CTUPLE_SIZE = return () | otherwise = addErr $ TcRnUnknownMessage $ mkPlainError noHints $ hang (text "Constraint tuple arity too large:" <+> int tup_size <+> parens (text "max arity =" <+> int mAX_CTUPLE_SIZE)) 2 (text "Instead, use a nested tuple") {- ********************************************************************* * * Generating code for HsExpanded See Note [Handling overloaded and rebindable constructs] * * ********************************************************************* -} wrapGenSpan :: a -> LocatedAn an a -- Wrap something in a "generatedSrcSpan" -- See Note [Rebindable syntax and HsExpansion] wrapGenSpan x = L (noAnnSrcSpan generatedSrcSpan) x genHsApps :: Name -> [LHsExpr GhcRn] -> HsExpr GhcRn genHsApps fun args = foldl genHsApp (genHsVar fun) args genHsApp :: HsExpr GhcRn -> LHsExpr GhcRn -> HsExpr GhcRn genHsApp fun arg = HsApp noAnn (wrapGenSpan fun) arg genLHsVar :: Name -> LHsExpr GhcRn genLHsVar nm = wrapGenSpan $ genHsVar nm genHsVar :: Name -> HsExpr GhcRn genHsVar nm = HsVar noExtField $ wrapGenSpan nm genAppType :: HsExpr GhcRn -> HsType (NoGhcTc GhcRn) -> HsExpr GhcRn genAppType expr = HsAppType noExtField (wrapGenSpan expr) . mkEmptyWildCardBndrs . wrapGenSpan genHsIntegralLit :: IntegralLit -> LocatedAn an (HsExpr GhcRn) genHsIntegralLit lit = wrapGenSpan $ HsLit noAnn (HsInt noExtField lit) genHsTyLit :: FastString -> HsType GhcRn genHsTyLit = HsTyLit noExtField . HsStrTy NoSourceText