Teo Camarasu pushed to branch wip/abstract-q at Glasgow Haskell Compiler / GHC Commits: 44cc53fe by Teo Camarasu at 2026-05-06T09:24:24+01:00 Make Q abstract This patch aims to clearly demarcate the internal and external interface of Q. In the past the `Quasi` typeclass was both part of the external, public-facing interface, and was used to give the implementation of `Q`. Now we separate out these two distinct roles. `Quasi` continues to exist in the public interface, but we introduce a new `MetaHandlers` type, which is equivalent to `Dict Quasi`. `Q a` is now defined to be `MetaHandlers IO -> IO a`, and, crucially, the constructor and the new `MetaHandlers` type are not exposed from the public interface. This gives us the ability to vary the interface on the GHC side without forcing a breaking change on the `template-haskell` side. Similarly `template-haskell` has more freedom to change the `Quasi` typeclass without needing any changes in `lib:ghc`. Implements https://github.com/ghc-proposals/ghc-proposals/pull/70 - - - - - 9 changed files: - + changelog.d/AbstractQ - compiler/GHC/Data/IOEnv.hs - compiler/GHC/Tc/Gen/Splice.hs - compiler/GHC/Tc/Gen/Splice.hs-boot - libraries/ghc-internal/src/GHC/Internal/TH/Lib.hs - libraries/ghc-internal/src/GHC/Internal/TH/Monad.hs - libraries/ghci/GHCi/TH.hs - libraries/template-haskell/Language/Haskell/TH/Syntax.hs - testsuite/tests/interface-stability/template-haskell-exports.stdout Changes: ===================================== changelog.d/AbstractQ ===================================== @@ -0,0 +1,7 @@ +section: template-haskell +synopsis: Hide the implementation of Q +description: The constructor of Q is now hidden. + This is done to improve the stability of ``template-haskell``. + To minimize breakage, we have added a new ``qRunQ`` operation to ``Quasi``. +mrs: !15696 +issues: TODO ===================================== compiler/GHC/Data/IOEnv.hs ===================================== @@ -29,7 +29,7 @@ module GHC.Data.IOEnv ( -- I/O operations IORef, newMutVar, readMutVar, writeMutVar, updMutVar, - atomicUpdMutVar, atomicUpdMutVar' + atomicUpdMutVar, atomicUpdMutVar', unliftIOEnv ) where import GHC.Prelude @@ -258,3 +258,10 @@ updEnv upd (IOEnv m) = IOEnv (\ env -> m (upd env)) updEnvIO :: (env -> IO env') -> IOEnv env' a -> IOEnv env a {-# INLINE updEnvIO #-} updEnvIO upd (IOEnv m) = IOEnv (\ env -> m =<< upd env) + +unliftIOEnv :: forall env b. ((forall a. IOEnv env a -> IO a) -> IO b) -> IOEnv env b +unliftIOEnv k = IOEnv $ \env -> + let + unlift :: forall a. IOEnv env a -> IO a + unlift (IOEnv m) = m env + in k unlift ===================================== compiler/GHC/Tc/Gen/Splice.hs ===================================== @@ -25,7 +25,7 @@ module GHC.Tc.Gen.Splice( tcTypedSplice, tcTypedBracket, tcUntypedBracket, runAnnotation, getUntypedSpliceBody, - runMetaE, runMetaP, runMetaT, runMetaD, runQuasi, + runMetaE, runMetaP, runMetaT, runMetaD, runQinTcM, tcTopSpliceExpr, lookupThName_maybe, defaultRunMeta, runMeta', runRemoteModFinalizers, finishTH, runTopSplice @@ -138,6 +138,7 @@ import qualified GHC.LanguageExtensions as LangExt -- THSyntax gives access to internal functions and data types import qualified GHC.Boot.TH.Syntax as TH import qualified GHC.Boot.TH.Monad as TH +import GHC.Boot.TH.Monad (MetaHandlers(..)) import qualified GHC.Boot.TH.Ppr as TH #if defined(HAVE_INTERNAL_INTERPRETER) @@ -1138,8 +1139,8 @@ convertAnnotationWrapper fhv = do ************************************************************************ -} -runQuasi :: TH.Q a -> TcM a -runQuasi act = TH.runQ act +runQinTcM :: TH.Q a -> TcM a +runQinTcM (TH.Q act) = unliftIOEnv $ \runInIO -> liftIO $ act (metaHandlersTcM runInIO) runRemoteModFinalizers :: ThModFinalizers -> TcM () runRemoteModFinalizers (ThModFinalizers finRefs) = do @@ -1152,7 +1153,7 @@ runRemoteModFinalizers (ThModFinalizers finRefs) = do #if defined(HAVE_INTERNAL_INTERPRETER) InternalInterp -> do qs <- liftIO (withForeignRefs finRefs $ mapM localRef) - runQuasi $ sequence_ qs + runQinTcM $ sequence_ qs #endif ExternalInterp ext -> withExtInterp ext $ \inst -> do @@ -1466,70 +1467,14 @@ when showing an error message. To call runQ in the Tc monad, we need to make TcM an instance of Quasi: -} -instance TH.Quasi TcM where - qNewName s = do { u <- newUnique - ; let i = toInteger (getKey u) - ; return (TH.mkNameU s i) } +-- 'msg' is forced to ensure exceptions don't escape, +-- see Note [Exceptions in TH] +report :: Bool -> [Char] -> TcM () +report True msg = seqList msg $ addErr $ TcRnTHError $ ReportCustomQuasiError True msg +report False msg = seqList msg $ addDiagnostic $ TcRnTHError $ ReportCustomQuasiError False msg - -- 'msg' is forced to ensure exceptions don't escape, - -- see Note [Exceptions in TH] - qReport True msg = seqList msg $ addErr $ TcRnTHError $ ReportCustomQuasiError True msg - qReport False msg = seqList msg $ addDiagnostic $ TcRnTHError $ ReportCustomQuasiError False msg - - qLocation :: TcM TH.Loc - qLocation = do { m <- getModule - ; l <- getSrcSpanM - ; r <- case l of - RealSrcSpan s _ -> return s - GeneratedSrcSpan{} -> pprPanic "qLocation: generatedSrcSpan" - (pprGeneratedSrcSpanDetails) - UnhelpfulSpan _ -> pprPanic "qLocation: Unhelpful location" - (ppr l) - ; return (TH.Loc { TH.loc_filename = unpackFS (srcSpanFile r) - , TH.loc_module = moduleNameString (moduleName m) - , TH.loc_package = unitString (moduleUnit m) - , TH.loc_start = (srcSpanStartLine r, srcSpanStartCol r) - , TH.loc_end = (srcSpanEndLine r, srcSpanEndCol r) }) } - - qLookupName = lookupName - qReify = reify - qReifyFixity nm = lookupThName nm >>= reifyFixity - qReifyType = reifyTypeOfThing - qReifyInstances = reifyInstances - qReifyRoles = reifyRoles - qReifyAnnotations = reifyAnnotations - qReifyModule = reifyModule - qReifyConStrictness nm = do { nm' <- lookupThName nm - ; dc <- tcLookupDataCon nm' - ; let bangs = dataConImplBangs dc - ; return (map reifyDecidedStrictness bangs) } - - -- For qRecover, discard error messages if - -- the recovery action is chosen. Otherwise - -- we'll only fail higher up. - qRecover recover main = tryTcDiscardingErrs recover main - - qGetPackageRoot = do - dflags <- getDynFlags - return $ fromMaybe "." (workingDirectory dflags) - - qAddDependentFile fp = do - ref <- fmap tcg_dependent_files getGblEnv - dep_files <- readTcRef ref - writeTcRef ref (fp:dep_files) - - qAddDependentDirectory dp = do - ref <- fmap tcg_dependent_dirs getGblEnv - dep_dirs <- readTcRef ref - writeTcRef ref (dp:dep_dirs) - - qAddTempFile suffix = do - dflags <- getDynFlags - logger <- getLogger - tmpfs <- hsc_tmpfs <$> getTopEnv - liftIO $ newTempName logger tmpfs (tmpDir dflags) TFL_GhcSession suffix - - qAddTopDecls thds = do +addTopDecls :: [TH.Dec] -> TcM () +addTopDecls thds = do exts <- fmap extensionFlags getDynFlags l <- getSrcSpanM th_origin <- getThSpliceOrigin @@ -1557,52 +1502,13 @@ instance TH.Quasi TcM where bindName :: RdrName -> TcM () bindName (Exact n) = do { th_topnames_var <- fmap tcg_th_topnames getGblEnv - ; updTcRef th_topnames_var (\ns -> extendNameSet ns n) - } + ; updTcRef th_topnames_var (\ns -> extendNameSet ns n) + } bindName name = addErr $ TcRnTHError $ THNameError $ NonExactName name - qAddForeignFilePath lang fp = do - var <- fmap tcg_th_foreign_files getGblEnv - updTcRef var ((lang, fp) :) - - qAddModFinalizer fin = do - r <- liftIO $ mkRemoteRef fin - fref <- liftIO $ mkForeignRef r (freeRemoteRef r) - addModFinalizerRef fref - - qAddCorePlugin plugin = do - hsc_env <- getTopEnv - let fc = hsc_FC hsc_env - let home_unit = hsc_home_unit hsc_env - let dflags = hsc_dflags hsc_env - let fopts = initFinderOpts dflags - r <- liftIO $ findHomeModule fc fopts home_unit (mkModuleName plugin) - let err = TcRnTHError $ AddInvalidCorePlugin plugin - case r of - Found {} -> addErr err - FoundMultiple {} -> addErr err - _ -> return () - th_coreplugins_var <- tcg_th_coreplugins <$> getGblEnv - updTcRef th_coreplugins_var (plugin:) - - qGetQ :: forall a. Typeable a => TcM (Maybe a) - qGetQ = do - th_state_var <- fmap tcg_th_state getGblEnv - th_state <- readTcRef th_state_var - -- See #10596 for why we use a scoped type variable here. - return (Map.lookup (typeRep (Proxy :: Proxy a)) th_state >>= fromDynamic) - - qPutQ x = do - th_state_var <- fmap tcg_th_state getGblEnv - updTcRef th_state_var (\m -> Map.insert (typeOf x) (toDyn x) m) - - qIsExtEnabled = xoptM - - qExtsEnabled = - EnumSet.toList . extensionFlags . hsc_dflags <$> getTopEnv - - qPutDoc doc_loc s = do +putDoc :: TH.DocLoc -> String -> TcM () +putDoc doc_loc s = do th_doc_var <- tcg_th_docs <$> getGblEnv resolved_doc_loc <- resolve_loc doc_loc is_local <- checkLocalName resolved_doc_loc @@ -1624,15 +1530,133 @@ instance TH.Quasi TcM where checkLocalName (InstDoc n) = nameIsLocalOrFrom <$> getModule <*> pure n checkLocalName ModuleDoc = pure True - - qGetDoc (TH.DeclDoc n) = lookupThName n >>= lookupDeclDoc - qGetDoc (TH.InstDoc t) = lookupThInstName t >>= lookupDeclDoc - qGetDoc (TH.ArgDoc n i) = lookupThName n >>= lookupArgDoc i - qGetDoc TH.ModuleDoc = do +getDoc :: TH.DocLoc -> TcM (Maybe String) +getDoc (TH.DeclDoc n) = lookupThName n >>= lookupDeclDoc +getDoc (TH.InstDoc t) = lookupThInstName t >>= lookupDeclDoc +getDoc (TH.ArgDoc n i) = lookupThName n >>= lookupArgDoc i +getDoc TH.ModuleDoc = do df <- getDynFlags docs <- getGblEnv >>= extractDocs df return (renderHsDocString . hsDocString <$> (docs_mod_hdr =<< docs)) +getQ :: forall a. Typeable a => TcM (Maybe a) +getQ = do + th_state_var <- fmap tcg_th_state getGblEnv + th_state <- readTcRef th_state_var + -- See #10596 for why we use a scoped type variable here. + return (Map.lookup (typeRep (Proxy :: Proxy a)) th_state >>= fromDynamic) + +location :: TcM TH.Loc +location = do { m <- getModule + ; l <- getSrcSpanM + ; r <- case l of + RealSrcSpan s _ -> return s + GeneratedSrcSpan{} -> pprPanic "qLocation: generatedSrcSpan" + (pprGeneratedSrcSpanDetails) + UnhelpfulSpan _ -> pprPanic "qLocation: Unhelpful location" + (ppr l) + ; return (TH.Loc { TH.loc_filename = unpackFS (srcSpanFile r) + , TH.loc_module = moduleNameString (moduleName m) + , TH.loc_package = unitString (moduleUnit m) + , TH.loc_start = (srcSpanStartLine r, srcSpanStartCol r) + , TH.loc_end = (srcSpanEndLine r, srcSpanEndCol r) }) } + +metaHandlersTcM :: (forall x. TcM x -> IO x) -> TH.MetaHandlers IO +metaHandlersTcM runInIO = TH.MetaHandlers { + mLiftIO = id + -- We are careful to use the TcM instance not the one for IO, since that would lead to a different error. + , mFail = \s -> runInIO $ fail @TcM s + , mNewName = \s -> runInIO $ do { u <- newUnique + ; let i = toInteger (getKey u) + ; return (TH.mkNameU s i) } + + , mReport = fmap runInIO . report + + , mLocation = runInIO location + + , mLookupName = fmap runInIO . lookupName + , mReify = runInIO . reify + , mReifyFixity = \nm -> runInIO $ lookupThName nm >>= reifyFixity + , mReifyType = runInIO . reifyTypeOfThing + , mReifyInstances = fmap runInIO . reifyInstances + , mReifyRoles = runInIO . reifyRoles + , mReifyAnnotations = runInIO . reifyAnnotations + , mReifyModule = runInIO . reifyModule + , mReifyConStrictness = \nm -> runInIO $ do + { nm' <- lookupThName nm + ; dc <- tcLookupDataCon nm' + ; let bangs = dataConImplBangs dc + ; return (map reifyDecidedStrictness bangs) } + + -- For qRecover, discard error messages if + -- the recovery action is chosen. Otherwise + -- we'll only fail higher up. + -- NB: extremely subtle!!! TODO: write up note + -- tryTcDiscardingErrs manipulates the reader env so we need to be careful we don't sneak in the outside env + , mRecover = \recover main -> runInIO $ tryTcDiscardingErrs (runQinTcM recover) (runQinTcM main) + + , mGetPackageRoot = runInIO $ do + dflags <- getDynFlags + return $ fromMaybe "." (workingDirectory dflags) + + , mAddDependentFile = \fp -> runInIO $ do + ref <- fmap tcg_dependent_files getGblEnv + dep_files <- readTcRef ref + writeTcRef ref (fp:dep_files) + + , mAddDependentDirectory = \dp -> runInIO $ do + ref <- fmap tcg_dependent_dirs getGblEnv + dep_dirs <- readTcRef ref + writeTcRef ref (dp:dep_dirs) + + , mAddTempFile = \suffix -> runInIO $ do + dflags <- getDynFlags + logger <- getLogger + tmpfs <- hsc_tmpfs <$> getTopEnv + liftIO $ newTempName logger tmpfs (tmpDir dflags) TFL_GhcSession suffix + + , mAddTopDecls = runInIO . addTopDecls + + , mAddForeignFilePath = \lang fp -> runInIO $ do + var <- fmap tcg_th_foreign_files getGblEnv + updTcRef var ((lang, fp) :) + + , mAddModFinalizer = \fin -> runInIO $ do + r <- liftIO $ mkRemoteRef fin + fref <- liftIO $ mkForeignRef r (freeRemoteRef r) + addModFinalizerRef fref + + , mAddCorePlugin = \plugin -> runInIO $ do + hsc_env <- getTopEnv + let fc = hsc_FC hsc_env + let home_unit = hsc_home_unit hsc_env + let dflags = hsc_dflags hsc_env + let fopts = initFinderOpts dflags + r <- liftIO $ findHomeModule fc fopts home_unit (mkModuleName plugin) + let err = TcRnTHError $ AddInvalidCorePlugin plugin + case r of + Found {} -> addErr err + FoundMultiple {} -> addErr err + _ -> return () + th_coreplugins_var <- tcg_th_coreplugins <$> getGblEnv + updTcRef th_coreplugins_var (plugin:) + + , mGetQ = runInIO getQ + + , mPutQ = \x -> runInIO $ do + th_state_var <- fmap tcg_th_state getGblEnv + updTcRef th_state_var (\m -> Map.insert (typeOf x) (toDyn x) m) + + , mIsExtEnabled = runInIO . xoptM + + , mExtsEnabled = runInIO $ + EnumSet.toList . extensionFlags . hsc_dflags <$> getTopEnv + + , mPutDoc = fmap runInIO . putDoc + + , mGetDoc = runInIO . getDoc + } + -- | Looks up documentation for a declaration in first the current module, -- otherwise tries to find it in another module via 'hscGetModuleInterface'. lookupDeclDoc :: Name -> TcM (Maybe String) @@ -1788,7 +1812,7 @@ runTH ty fhv = do InternalInterp -> do -- Run it in the local TcM hv <- liftIO $ wormhole interp fhv - r <- runQuasi (unsafeCoerce hv :: TH.Q a) + r <- runQinTcM (unsafeCoerce hv :: TH.Q a) return r #endif @@ -1797,7 +1821,7 @@ runTH ty fhv = do -- Remote GHCi, see Note [Remote Template Haskell] in -- libraries/ghci/GHCi/TH.hs. rstate <- getTHState inst - loc <- TH.qLocation + loc <- location -- run a remote TH request r <- liftIO $ withForeignRef rstate $ \state_hv -> @@ -1913,32 +1937,32 @@ wrapTHResult tcm = do handleTHMessage :: THMessage a -> TcM a handleTHMessage msg = case msg of - NewName a -> wrapTHResult $ TH.qNewName a - Report b str -> wrapTHResult $ TH.qReport b str - LookupName b str -> wrapTHResult $ TH.qLookupName b str - Reify n -> wrapTHResult $ TH.qReify n - ReifyFixity n -> wrapTHResult $ TH.qReifyFixity n - ReifyType n -> wrapTHResult $ TH.qReifyType n - ReifyInstances n ts -> wrapTHResult $ TH.qReifyInstances n ts - ReifyRoles n -> wrapTHResult $ TH.qReifyRoles n + NewName a -> wrapTHResult $ runQinTcM $ TH.newName a + Report b str -> wrapTHResult $ runQinTcM $ TH.report b str + LookupName b str -> wrapTHResult $ runQinTcM $ TH.lookupName b str + Reify n -> wrapTHResult $ runQinTcM $ TH.reify n + ReifyFixity n -> wrapTHResult $ runQinTcM $ TH.reifyFixity n + ReifyType n -> wrapTHResult $ runQinTcM $ TH.reifyType n + ReifyInstances n ts -> wrapTHResult $ runQinTcM $ TH.reifyInstances n ts + ReifyRoles n -> wrapTHResult $ runQinTcM $ TH.reifyRoles n ReifyAnnotations lookup tyrep -> wrapTHResult $ (map B.pack <$> getAnnotationsByTypeRep lookup tyrep) - ReifyModule m -> wrapTHResult $ TH.qReifyModule m - ReifyConStrictness nm -> wrapTHResult $ TH.qReifyConStrictness nm - GetPackageRoot -> wrapTHResult $ TH.qGetPackageRoot - AddDependentFile f -> wrapTHResult $ TH.qAddDependentFile f - AddDependentDirectory d -> wrapTHResult $ TH.qAddDependentDirectory d - AddTempFile s -> wrapTHResult $ TH.qAddTempFile s + ReifyModule m -> wrapTHResult $ runQinTcM $ TH.reifyModule m + ReifyConStrictness nm -> wrapTHResult $ runQinTcM $ TH.reifyConStrictness nm + GetPackageRoot -> wrapTHResult $ runQinTcM $ TH.getPackageRoot + AddDependentFile f -> wrapTHResult $ runQinTcM $ TH.addDependentFile f + AddDependentDirectory d -> wrapTHResult $ runQinTcM $ TH.addDependentDirectory d + AddTempFile s -> wrapTHResult $ runQinTcM $ TH.addTempFile s AddModFinalizer r -> do interp <- hscInterp <$> getTopEnv wrapTHResult $ liftIO (mkFinalizedHValue interp r) >>= addModFinalizerRef - AddCorePlugin str -> wrapTHResult $ TH.qAddCorePlugin str - AddTopDecls decs -> wrapTHResult $ TH.qAddTopDecls decs - AddForeignFilePath lang str -> wrapTHResult $ TH.qAddForeignFilePath lang str - IsExtEnabled ext -> wrapTHResult $ TH.qIsExtEnabled ext - ExtsEnabled -> wrapTHResult $ TH.qExtsEnabled - PutDoc l s -> wrapTHResult $ TH.qPutDoc l s - GetDoc l -> wrapTHResult $ TH.qGetDoc l + AddCorePlugin str -> wrapTHResult $ runQinTcM $ TH.addCorePlugin str + AddTopDecls decs -> wrapTHResult $ runQinTcM $ TH.addTopDecls decs + AddForeignFilePath lang str -> wrapTHResult $ runQinTcM $ TH.addForeignFilePath lang str + IsExtEnabled ext -> wrapTHResult $ runQinTcM $ TH.isExtEnabled ext + ExtsEnabled -> wrapTHResult $ runQinTcM $ TH.extsEnabled + PutDoc l s -> wrapTHResult $ runQinTcM $ TH.putDoc l s + GetDoc l -> wrapTHResult $ runQinTcM $ TH.getDoc l FailIfErrs -> wrapTHResult failIfErrsM _ -> panic ("handleTHMessage: unexpected message " ++ show msg) ===================================== compiler/GHC/Tc/Gen/Splice.hs-boot ===================================== @@ -42,6 +42,6 @@ runMetaT :: LHsExpr GhcTc -> TcM (LHsType GhcPs) runMetaD :: LHsExpr GhcTc -> TcM [LHsDecl GhcPs] lookupThName_maybe :: TH.Name -> TcM (Maybe Name) -runQuasi :: TH.Q a -> TcM a +runQinTcM :: TH.Q a -> TcM a runRemoteModFinalizers :: ThModFinalizers -> TcM () finishTH :: TcM () ===================================== libraries/ghc-internal/src/GHC/Internal/TH/Lib.hs ===================================== @@ -1079,7 +1079,7 @@ withDecDoc :: String -> Q Dec -> Q Dec withDecDoc doc dec = do dec' <- dec case doc_loc dec' of - Just loc -> qAddModFinalizer $ qPutDoc loc doc + Just loc -> addModFinalizer $ putDoc loc doc Nothing -> pure () pure dec' where @@ -1128,7 +1128,7 @@ funD_doc :: Name -> [Q Clause] -> [Maybe String] -- ^ Documentation to attach to arguments -> Q Dec funD_doc nm cs mfun_doc arg_docs = do - qAddModFinalizer $ sequence_ + addModFinalizer $ sequence_ [putDoc (ArgDoc nm i) s | (i, Just s) <- zip [0..] arg_docs] let dec = funD nm cs case mfun_doc of @@ -1145,7 +1145,7 @@ dataD_doc :: Q Cxt -> Name -> [Q (TyVarBndr BndrVis)] -> Maybe (Q Kind) -- ^ Documentation to attach to the data declaration -> Q Dec dataD_doc ctxt tc tvs ksig cons_with_docs derivs mdoc = do - qAddModFinalizer $ mapM_ docCons cons_with_docs + addModFinalizer $ mapM_ docCons cons_with_docs let dec = dataD ctxt tc tvs ksig (map (\(con, _, _) -> con) cons_with_docs) derivs maybe dec (flip withDecDoc dec) mdoc @@ -1159,7 +1159,7 @@ newtypeD_doc :: Q Cxt -> Name -> [Q (TyVarBndr BndrVis)] -> Maybe (Q Kind) -- ^ Documentation to attach to the newtype declaration -> Q Dec newtypeD_doc ctxt tc tvs ksig con_with_docs@(con, _, _) derivs mdoc = do - qAddModFinalizer $ docCons con_with_docs + addModFinalizer $ docCons con_with_docs let dec = newtypeD ctxt tc tvs ksig con derivs maybe dec (flip withDecDoc dec) mdoc @@ -1172,7 +1172,7 @@ typeDataD_doc :: Name -> [Q (TyVarBndr BndrVis)] -> Maybe (Q Kind) -- ^ Documentation to attach to the data declaration -> Q Dec typeDataD_doc tc tvs ksig cons_with_docs mdoc = do - qAddModFinalizer $ mapM_ docCons cons_with_docs + addModFinalizer $ mapM_ docCons cons_with_docs let dec = typeDataD tc tvs ksig (map (\(con, _, _) -> con) cons_with_docs) maybe dec (flip withDecDoc dec) mdoc @@ -1186,7 +1186,7 @@ dataInstD_doc :: Q Cxt -> (Maybe [Q (TyVarBndr ())]) -> Q Type -> Maybe (Q Kind) -- ^ Documentation to attach to the instance declaration -> Q Dec dataInstD_doc ctxt mb_bndrs ty ksig cons_with_docs derivs mdoc = do - qAddModFinalizer $ mapM_ docCons cons_with_docs + addModFinalizer $ mapM_ docCons cons_with_docs let dec = dataInstD ctxt mb_bndrs ty ksig (map (\(con, _, _) -> con) cons_with_docs) derivs maybe dec (flip withDecDoc dec) mdoc @@ -1202,7 +1202,7 @@ newtypeInstD_doc :: Q Cxt -> (Maybe [Q (TyVarBndr ())]) -> Q Type -- ^ Documentation to attach to the instance declaration -> Q Dec newtypeInstD_doc ctxt mb_bndrs ty ksig con_with_docs@(con, _, _) derivs mdoc = do - qAddModFinalizer $ docCons con_with_docs + addModFinalizer $ docCons con_with_docs let dec = newtypeInstD ctxt mb_bndrs ty ksig con derivs maybe dec (flip withDecDoc dec) mdoc @@ -1212,7 +1212,7 @@ patSynD_doc :: Name -> Q PatSynArgs -> Q PatSynDir -> Q Pat -> [Maybe String] -- ^ Documentation to attach to the pattern arguments -> Q Dec patSynD_doc name args dir pat mdoc arg_docs = do - qAddModFinalizer $ sequence_ + addModFinalizer $ sequence_ [putDoc (ArgDoc name i) s | (i, Just s) <- zip [0..] arg_docs] let dec = patSynD name args dir pat maybe dec (flip withDecDoc dec) mdoc ===================================== libraries/ghc-internal/src/GHC/Internal/TH/Monad.hs ===================================== @@ -35,7 +35,7 @@ import GHC.Types (TYPE, RuntimeRep(..)) #else import GHC.Internal.Base ( Applicative(..), Functor(..), Monad(..), Monoid(..), Semigroup(..), String, - flip, id, (.), (++), + flip, id, (.), (++), ($), ) import GHC.Internal.Classes (not) import GHC.Internal.Data.Data hiding (Fixity(..)) @@ -59,145 +59,137 @@ import GHC.Internal.ForeignSrcLang import GHC.Internal.LanguageExtensions import GHC.Internal.TH.Syntax ------------------------------------------------------ --- --- The Quasi class --- ------------------------------------------------------ - -class (MonadIO m, MonadFail m) => Quasi m where - -- | Fresh names. See 'newName'. - qNewName :: String -> m Name - - ------- Error reporting and recovery ------- - -- | Report an error (True) or warning (False) - -- ...but carry on; use 'fail' to stop. See 'report'. - qReport :: Bool -> String -> m () - - -- | See 'recover'. - qRecover :: m a -- ^ the error handler - -> m a -- ^ action which may fail - -> m a -- ^ Recover from the monadic 'fail' - - ------- Inspect the type-checker's environment ------- - -- | True <=> type namespace, False <=> value namespace. See 'lookupName'. - qLookupName :: Bool -> String -> m (Maybe Name) - -- | See 'reify'. - qReify :: Name -> m Info - -- | See 'reifyFixity'. - qReifyFixity :: Name -> m (Maybe Fixity) - -- | See 'reifyType'. - qReifyType :: Name -> m Type - -- | Is (n tys) an instance? Returns list of matching instance Decs (with - -- empty sub-Decs) Works for classes and type functions. See 'reifyInstances'. - qReifyInstances :: Name -> [Type] -> m [Dec] - -- | See 'reifyRoles'. - qReifyRoles :: Name -> m [Role] - -- | See 'reifyAnnotations'. - qReifyAnnotations :: Data a => AnnLookup -> m [a] - -- | See 'reifyModule'. - qReifyModule :: Module -> m ModuleInfo - -- | See 'reifyConStrictness'. - qReifyConStrictness :: Name -> m [DecidedStrictness] - - -- | See 'location'. - qLocation :: m Loc - - -- | Input/output (dangerous). See 'runIO'. - qRunIO :: IO a -> m a - qRunIO = liftIO - -- | See 'getPackageRoot'. - qGetPackageRoot :: m FilePath - - -- | See 'addDependentFile'. - qAddDependentFile :: FilePath -> m () - - -- | See 'addDependentDirectory'. - qAddDependentDirectory :: FilePath -> m () - - -- | See 'addTempFile'. - qAddTempFile :: String -> m FilePath - - -- | See 'addTopDecls'. - qAddTopDecls :: [Dec] -> m () - - -- | See 'addForeignFilePath'. - qAddForeignFilePath :: ForeignSrcLang -> String -> m () - - -- | See 'addModFinalizer'. - qAddModFinalizer :: Q () -> m () - - -- | See 'addCorePlugin'. - qAddCorePlugin :: String -> m () - - -- | See 'getQ'. - qGetQ :: Typeable a => m (Maybe a) - - -- | See 'putQ'. - qPutQ :: Typeable a => a -> m () - - -- | See 'isExtEnabled'. - qIsExtEnabled :: Extension -> m Bool - -- | See 'extsEnabled'. - qExtsEnabled :: m [Extension] - - -- | See 'putDoc'. - qPutDoc :: DocLoc -> String -> m () - -- | See 'getDoc'. - qGetDoc :: DocLoc -> m (Maybe String) +data MetaHandlers m = MetaHandlers { + mLiftIO :: forall a. IO a -> m a + , mFail :: forall a. String -> m a + -- | Fresh names. See 'newName'. + , mNewName :: String -> m Name + + ------- Error reporting and recovery ------- + -- | Report an error (True) or warning (False) + -- ...but carry on; use 'fail' to stop. See 'report'. + , mReport :: Bool -> String -> m () + + -- | See 'recover'. + , mRecover :: forall a. Q a -- ^ the error handler + -> Q a -- ^ action which may fail + -> m a -- ^ Recover from the monadic 'fail' + + ------- Inspect the type-checker's environment ------- + -- | True <=> type namespace, False <=> value namespace. See 'lookupName'. + , mLookupName :: Bool -> String -> m (Maybe Name) + -- | See 'reify'. + , mReify :: Name -> m Info + -- | See 'reifyFixity'. + , mReifyFixity :: Name -> m (Maybe Fixity) + -- | See 'reifyType'. + , mReifyType :: Name -> m Type + -- | Is (n tys) an instance? Returns list of matching instance Decs (with + -- empty sub-Decs) Works for classes and type functions. See 'reifyInstances'. + , mReifyInstances :: Name -> [Type] -> m [Dec] + -- | See 'reifyRoles'. + , mReifyRoles :: Name -> m [Role] + -- | See 'reifyAnnotations'. + , mReifyAnnotations :: forall a. Data a => AnnLookup -> m [a] + -- | See 'reifyModule'. + , mReifyModule :: Module -> m ModuleInfo + -- | See 'reifyConStrictness'. + , mReifyConStrictness :: Name -> m [DecidedStrictness] + + -- | See 'location'. + , mLocation :: m Loc + + -- | See 'getPackageRoot'. + , mGetPackageRoot :: m FilePath + + -- | See 'addDependentFile'. + , mAddDependentFile :: FilePath -> m () + + -- | See 'addDependentDirectory'. + , mAddDependentDirectory :: FilePath -> m () + + -- | See 'addTempFile'. + , mAddTempFile :: String -> m FilePath + + -- | See 'addTopDecls'. + , mAddTopDecls :: [Dec] -> m () + + -- | See 'addForeignFilePath'. + , mAddForeignFilePath :: ForeignSrcLang -> String -> m () + + -- | See 'addModFinalizer'. + , mAddModFinalizer :: Q () -> m () + + -- | See 'addCorePlugin'. + , mAddCorePlugin :: String -> m () + + -- | See 'getQ'. + , mGetQ :: forall a. Typeable a => m (Maybe a) + + -- | See 'putQ'. + , mPutQ :: forall a. Typeable a => a -> m () + + -- | See 'isExtEnabled'. + , mIsExtEnabled :: Extension -> m Bool + -- | See 'extsEnabled'. + , mExtsEnabled :: m [Extension] + + -- | See 'putDoc'. + , mPutDoc :: DocLoc -> String -> m () + -- | See 'getDoc'. + , mGetDoc :: DocLoc -> m (Maybe String) + } ------------------------------------------------------ --- The IO instance of Quasi ------------------------------------------------------ +badIO :: String -> IO a +badIO op = do { hPutStrLn stderr ("Can't do `" ++ op ++ "' in the IO monad") + ; fail "Template Haskell failure" } --- | This instance is used only when running a Q --- computation in the IO monad, usually just to --- print the result. There is no interesting --- type environment, so reification isn't going to --- work. -instance Quasi IO where - qNewName = newNameIO - - qReport True msg = hPutStrLn stderr ("Template Haskell error: " ++ msg) - qReport False msg = hPutStrLn stderr ("Template Haskell error: " ++ msg) - - qLookupName _ _ = badIO "lookupName" - qReify _ = badIO "reify" - qReifyFixity _ = badIO "reifyFixity" - qReifyType _ = badIO "reifyFixity" - qReifyInstances _ _ = badIO "reifyInstances" - qReifyRoles _ = badIO "reifyRoles" - qReifyAnnotations _ = badIO "reifyAnnotations" - qReifyModule _ = badIO "reifyModule" - qReifyConStrictness _ = badIO "reifyConStrictness" - qLocation = badIO "currentLocation" - qRecover _ _ = badIO "recover" -- Maybe we could fix this? - qGetPackageRoot = badIO "getProjectRoot" - qAddDependentFile _ = badIO "addDependentFile" - qAddTempFile _ = badIO "addTempFile" - qAddTopDecls _ = badIO "addTopDecls" - qAddForeignFilePath _ _ = badIO "addForeignFilePath" - qAddModFinalizer _ = badIO "addModFinalizer" - qAddCorePlugin _ = badIO "addCorePlugin" - qGetQ = badIO "getQ" - qPutQ _ = badIO "putQ" - qIsExtEnabled _ = badIO "isExtEnabled" - qExtsEnabled = badIO "extsEnabled" - qPutDoc _ _ = badIO "putDoc" - qGetDoc _ = badIO "getDoc" - qAddDependentDirectory _ = badIO "AddDependentDirectory" +metaHandlersIO :: MetaHandlers IO +metaHandlersIO = MetaHandlers { + mLiftIO = id + , mFail = fail + , mNewName = newNameIO + , mReport = \b msg -> + if b then + hPutStrLn stderr ("Template Haskell error: " ++ msg) + else + hPutStrLn stderr ("Template Haskell error: " ++ msg) -- TODO: should this be different from above? + , mLookupName = \ _ _ -> badIO "lookupName" + , mReify = \_ -> badIO "reify" + , mReifyFixity = \_ -> badIO "reifyFixity" + , mReifyType = \_ -> badIO "reifyFixity" + , mReifyInstances = \_ _ -> badIO "reifyInstances" + , mReifyRoles = \_ -> badIO "reifyRoles" + , mReifyAnnotations = \_ -> badIO "reifyAnnotations" + , mReifyModule = \_ -> badIO "reifyModule" + , mReifyConStrictness = \_ -> badIO "reifyConStrictness" + , mLocation = badIO "currentLocation" + , mRecover = \_ _ -> badIO "recover" -- Maybe we could fix this? + , mGetPackageRoot = badIO "getProjectRoot" + , mAddDependentFile = \_ -> badIO "addDependentFile" + , mAddTempFile = \_ -> badIO "addTempFile" + , mAddTopDecls = \_ -> badIO "addTopDecls" + , mAddForeignFilePath = \_ _ -> badIO "addForeignFilePath" + , mAddModFinalizer = \_ -> badIO "addModFinalizer" + , mAddCorePlugin = \_ -> badIO "addCorePlugin" + , mGetQ = badIO "getQ" + , mPutQ = \_ -> badIO "putQ" + , mIsExtEnabled = \_ -> badIO "isExtEnabled" + , mExtsEnabled = badIO "extsEnabled" + , mPutDoc = \_ _ -> badIO "putDoc" + , mGetDoc = \_ -> badIO "getDoc" + , mAddDependentDirectory = \_ -> badIO "AddDependentDirectory" + } instance Quote IO where newName = newNameIO + + newNameIO :: String -> IO Name newNameIO s = do { n <- atomicModifyIORef' counter (\x -> (x + 1, x)) ; pure (mkNameU s n) } -badIO :: String -> IO a -badIO op = do { qReport True ("Can't do `" ++ op ++ "' in the IO monad") - ; fail "Template Haskell failure" } - -- Global variable to generate unique symbols counter :: IORef Uniq {-# NOINLINE counter #-} @@ -220,36 +212,22 @@ counter = unsafePerformIO (newIORef 0) -- inversion](https://en.wikipedia.org/wiki/Dependency_inversion_principle), -- providing an abstract interface for the user which is later concretely -- fufilled by an concrete 'Quasi' instance, internal to GHC. -newtype Q a = Q { unQ :: forall m. Quasi m => m a } - --- | \"Runs\" the 'Q' monad. Normal users of Template Haskell --- should not need this function, as the splice brackets @$( ... )@ --- are the usual way of running a 'Q' computation. --- --- This function is primarily used in GHC internals, and for debugging --- splices by running them in 'IO'. --- --- Note that many functions in 'Q', such as 'reify' and other compiler --- queries, are not supported when running 'Q' in 'IO'; these operations --- simply fail at runtime. Indeed, the only operations guaranteed to succeed --- are 'newName', 'runIO', 'reportError' and 'reportWarning'. -runQ :: Quasi m => Q a -> m a -runQ (Q m) = m +newtype Q a = Q { unQ :: MetaHandlers IO -> IO a } instance Monad Q where - Q m >>= k = Q (m >>= \x -> unQ (k x)) + Q m >>= k = Q $ \h -> (m h >>= \x -> unQ (k x) h) (>>) = (*>) instance MonadFail Q where - fail s = report True s >> Q (fail "Q monad failure") + fail s = report True s >> Q (\h -> mFail h "Q monad failure") instance Functor Q where - fmap f (Q x) = Q (fmap f x) + fmap f (Q x) = Q $ \h -> fmap f (x h) instance Applicative Q where - pure x = Q (pure x) - Q f <*> Q x = Q (f <*> x) - Q m *> Q n = Q (m *> n) + pure x = Q $ \_ -> pure x + Q f <*> Q x = Q $ \h -> (f h <*> x h) + Q m *> Q n = Q $ \h -> (m h *> n h) -- | @since 2.17.0.0 instance Semigroup a => Semigroup (Q a) where @@ -319,7 +297,7 @@ class Monad m => Quote m where newName :: String -> m Name instance Quote Q where - newName s = Q (qNewName s) + newName s = Q $ \h -> mNewName h s ----------------------------------------------------- -- @@ -517,7 +495,7 @@ joinCode = flip bindCode id -- | Report an error (True) or warning (False), -- but carry on; use 'fail' to stop. report :: Bool -> String -> Q () -report b s = Q (qReport b s) +report b s = Q $ \h -> mReport h b s {-# DEPRECATED report "Use reportError or reportWarning instead" #-} -- deprecated in 7.6 -- | Report an error to the user, but allow the current splice's computation to carry on. To abort the computation, use 'fail'. @@ -532,20 +510,20 @@ reportWarning = report False recover :: Q a -- ^ handler to invoke on failure -> Q a -- ^ computation to run -> Q a -recover (Q r) (Q m) = Q (qRecover r m) +recover rec main = Q $ \h -> mRecover h rec main -- We don't export lookupName; the Bool isn't a great API -- Instead we export lookupTypeName, lookupValueName lookupName :: Bool -> String -> Q (Maybe Name) -lookupName ns s = Q (qLookupName ns s) +lookupName ns s = Q $ \h -> mLookupName h ns s -- | Look up the given name in the (type namespace of the) current splice's scope. See "Language.Haskell.TH.Syntax#namelookup" for more details. lookupTypeName :: String -> Q (Maybe Name) -lookupTypeName s = Q (qLookupName True s) +lookupTypeName s = Q $ \h -> mLookupName h True s -- | Look up the given name in the (value namespace of the) current splice's scope. See "Language.Haskell.TH.Syntax#namelookup" for more details. lookupValueName :: String -> Q (Maybe Name) -lookupValueName s = Q (qLookupName False s) +lookupValueName s = Q $ \h -> mLookupName h False s {- Note [Name lookup] @@ -620,7 +598,7 @@ To ensure we get information about @D@-the-value, use 'lookupValueName': and to get information about @D@-the-type, use 'lookupTypeName'. -} reify :: Name -> Q Info -reify v = Q (qReify v) +reify v = Q $ \h -> mReify h v {- | @reifyFixity nm@ attempts to find a fixity declaration for @nm@. For example, if the function @foo@ has the fixity declaration @infixr 7 foo@, then @@ -629,7 +607,7 @@ example, if the function @foo@ has the fixity declaration @infixr 7 foo@, then 'Nothing', so you may assume @bar@ has 'defaultFixity'. -} reifyFixity :: Name -> Q (Maybe Fixity) -reifyFixity nm = Q (qReifyFixity nm) +reifyFixity nm = Q $ \h -> mReifyFixity h nm {- | @reifyType nm@ attempts to find the type or kind of @nm@. For example, @reifyType 'not@ returns @Bool -> Bool@, and @@ -637,7 +615,7 @@ reifyFixity nm = Q (qReifyFixity nm) This works even if there's no explicit signature and the type or kind is inferred. -} reifyType :: Name -> Q Type -reifyType nm = Q (qReifyType nm) +reifyType nm = Q $ \h -> mReifyType h nm {- | Template Haskell is capable of reifying information about types and terms defined in previous declaration groups. Top-level declaration splices break up @@ -729,7 +707,7 @@ has some discussion around this. -} reifyInstances :: Name -> [Type] -> Q [InstanceDec] -reifyInstances cls tys = Q (qReifyInstances cls tys) +reifyInstances cls tys = Q $ \h -> mReifyInstances h cls tys {- | @reifyRoles nm@ returns the list of roles associated with the parameters (both visible and invisible) of @@ -748,20 +726,20 @@ and @reifyRoles Proxy@, we will get @['NominalR', 'PhantomR']@. The 'NominalR' i the role of the invisible @k@ parameter. Kind parameters are always nominal. -} reifyRoles :: Name -> Q [Role] -reifyRoles nm = Q (qReifyRoles nm) +reifyRoles nm = Q $ \h -> mReifyRoles h nm -- | @reifyAnnotations target@ returns the list of annotations -- associated with @target@. Only the annotations that are -- appropriately typed is returned. So if you have @Int@ and @String@ -- annotations for the same target, you have to call this function twice. reifyAnnotations :: Data a => AnnLookup -> Q [a] -reifyAnnotations an = Q (qReifyAnnotations an) +reifyAnnotations an = Q $ \h -> mReifyAnnotations h an -- | @reifyModule mod@ looks up information about module @mod@. To -- look up the current module, call this function with the return -- value of 'Language.Haskell.TH.Lib.thisModule'. reifyModule :: Module -> Q ModuleInfo -reifyModule m = Q (qReifyModule m) +reifyModule m = Q $ \h -> mReifyModule h m -- | @reifyConStrictness nm@ looks up the strictness information for the fields -- of the constructor with the name @nm@. Note that the strictness information @@ -776,7 +754,7 @@ reifyModule m = Q (qReifyModule m) -- circumstances, but it would return @['DecidedStrict', DecidedStrict]@ if the -- @-XStrictData@ language extension was enabled. reifyConStrictness :: Name -> Q [DecidedStrictness] -reifyConStrictness n = Q (qReifyConStrictness n) +reifyConStrictness n = Q $ \h -> mReifyConStrictness h n -- | Is the list of instances returned by 'reifyInstances' nonempty? -- @@ -789,7 +767,7 @@ isInstance nm tys = do { decs <- reifyInstances nm tys -- | The location at which this computation is spliced. location :: Q Loc -location = Q qLocation +location = Q mLocation -- |The 'runIO' function lets you run an I\/O computation in the 'Q' monad. -- Take care: you are guaranteed the ordering of calls to 'runIO' within @@ -799,7 +777,7 @@ location = Q qLocation -- necessarily flushed when the compiler finishes running, so you should -- flush them yourself. runIO :: IO a -> Q a -runIO m = Q (qRunIO m) +runIO m = Q $ \h -> mLiftIO h m -- | Get the package root for the current package which is being compiled. -- This can be set explicitly with the -package-root flag but is normally @@ -811,7 +789,7 @@ runIO m = Q (qRunIO m) -- change directory when compiling files but instead set the -package-root flag -- appropriately. getPackageRoot :: Q FilePath -getPackageRoot = Q qGetPackageRoot +getPackageRoot = Q mGetPackageRoot -- | Record external directories that runIO is using (dependent upon). -- The compiler can then recognize that it should re-compile the Haskell file @@ -830,7 +808,7 @@ getPackageRoot = Q qGetPackageRoot -- * The state of the directory is read at the interface generation time, -- not at the time of the function call. addDependentDirectory :: FilePath -> Q () -addDependentDirectory dp = Q (qAddDependentDirectory dp) +addDependentDirectory dp = Q $ \h -> mAddDependentDirectory h dp -- | Record external files that runIO is using (dependent upon). -- The compiler can then recognize that it should re-compile the Haskell file @@ -844,17 +822,17 @@ addDependentDirectory dp = Q (qAddDependentDirectory dp) -- -- * The dependency is based on file content, not a modification time addDependentFile :: FilePath -> Q () -addDependentFile fp = Q (qAddDependentFile fp) +addDependentFile fp = Q $ \h -> mAddDependentFile h fp -- | Obtain a temporary file path with the given suffix. The compiler will -- delete this file after compilation. addTempFile :: String -> Q FilePath -addTempFile suffix = Q (qAddTempFile suffix) +addTempFile suffix = Q $ \h -> mAddTempFile h suffix -- | Add additional top-level declarations. The added declarations will be type -- checked along with the current declaration group. addTopDecls :: [Dec] -> Q () -addTopDecls ds = Q (qAddTopDecls ds) +addTopDecls ds = Q $ \h -> mAddTopDecls h ds -- | Same as 'addForeignSource', but expects to receive a path pointing to the -- foreign file instead of a 'String' of its contents. Consider using this in @@ -863,7 +841,7 @@ addTopDecls ds = Q (qAddTopDecls ds) -- This is a good alternative to 'addForeignSource' when you are trying to -- directly link in an object file. addForeignFilePath :: ForeignSrcLang -> FilePath -> Q () -addForeignFilePath lang fp = Q (qAddForeignFilePath lang fp) +addForeignFilePath lang fp = Q $ \h -> mAddForeignFilePath h lang fp -- | Add a finalizer that will run in the Q monad after the current module has -- been type checked. This only makes sense when run within a top-level splice. @@ -872,7 +850,7 @@ addForeignFilePath lang fp = Q (qAddForeignFilePath lang fp) -- 'reify' is able to find the local definitions when executed inside the -- finalizer. addModFinalizer :: Q () -> Q () -addModFinalizer act = Q (qAddModFinalizer (unQ act)) +addModFinalizer act = Q $ \h -> mAddModFinalizer h act -- | Adds a core plugin to the compilation pipeline. -- @@ -882,7 +860,7 @@ addModFinalizer act = Q (qAddModFinalizer (unQ act)) -- to tell the compiler that we needed to compile first a plugin module in the -- current package. addCorePlugin :: String -> Q () -addCorePlugin plugin = Q (qAddCorePlugin plugin) +addCorePlugin plugin = Q $ \h -> mAddCorePlugin h plugin -- | Get state from the 'Q' monad. The state maintained by 'Q' is isomorphic to -- a type-indexed finite map. That is, @@ -896,20 +874,20 @@ addCorePlugin plugin = Q (qAddCorePlugin plugin) -- Note that the state is local to the Haskell module in which the Template -- Haskell expression is executed. getQ :: Typeable a => Q (Maybe a) -getQ = Q qGetQ +getQ = Q mGetQ -- | Replace the state in the 'Q' monad. Note that the state is local to the -- Haskell module in which the Template Haskell expression is executed. putQ :: Typeable a => a -> Q () -putQ x = Q (qPutQ x) +putQ x = Q $ \h -> mPutQ h x -- | Determine whether the given language extension is enabled in the 'Q' monad. isExtEnabled :: Extension -> Q Bool -isExtEnabled ext = Q (qIsExtEnabled ext) +isExtEnabled ext = Q $ \h -> mIsExtEnabled h ext -- | List all enabled language extensions. extsEnabled :: Q [Extension] -extsEnabled = Q qExtsEnabled +extsEnabled = Q mExtsEnabled -- | Add Haddock documentation to the specified location. This will overwrite -- any documentation at the location if it already exists. This will reify the @@ -928,48 +906,18 @@ extsEnabled = Q qExtsEnabled -- Adding documentation to anything outside of the current module will cause an -- error. putDoc :: DocLoc -> String -> Q () -putDoc t s = Q (qPutDoc t s) +putDoc t s = Q $ \h -> mPutDoc h t s -- | Retrieves the Haddock documentation at the specified location, if one -- exists. -- It can be used to read documentation on things defined outside of the current -- module, provided that those modules were compiled with the @-haddock@ flag. getDoc :: DocLoc -> Q (Maybe String) -getDoc n = Q (qGetDoc n) +getDoc n = Q $ \h -> mGetDoc h n instance MonadIO Q where liftIO = runIO -instance Quasi Q where - qNewName = newName - qReport = report - qRecover = recover - qReify = reify - qReifyFixity = reifyFixity - qReifyType = reifyType - qReifyInstances = reifyInstances - qReifyRoles = reifyRoles - qReifyAnnotations = reifyAnnotations - qReifyModule = reifyModule - qReifyConStrictness = reifyConStrictness - qLookupName = lookupName - qLocation = location - qGetPackageRoot = getPackageRoot - qAddDependentFile = addDependentFile - qAddDependentDirectory = addDependentDirectory - qAddTempFile = addTempFile - qAddTopDecls = addTopDecls - qAddForeignFilePath = addForeignFilePath - qAddModFinalizer = addModFinalizer - qAddCorePlugin = addCorePlugin - qGetQ = getQ - qPutQ = putQ - qIsExtEnabled = isExtEnabled - qExtsEnabled = extsEnabled - qPutDoc = putDoc - qGetDoc = getDoc - - ---------------------------------------------------- -- The following operations are used solely in GHC.HsToCore.Quote when -- desugaring brackets. They are not necessary for the user, who can use ===================================== libraries/ghci/GHCi/TH.hs ===================================== @@ -1,5 +1,5 @@ {-# LANGUAGE ScopedTypeVariables, StandaloneDeriving, DeriveGeneric, - TupleSections, RecordWildCards, InstanceSigs, CPP #-} + TupleSections, RecordWildCards, InstanceSigs, CPP, RankNTypes #-} {-# OPTIONS_GHC -fno-warn-name-shadowing #-} -- | @@ -164,58 +164,70 @@ ghcCmd m = GHCiQ $ \sRef -> do instance MonadIO GHCiQ where liftIO m = GHCiQ $ \_ -> m -instance TH.Quasi GHCiQ where - qNewName str = ghcCmd (NewName str) - qReport isError msg = ghcCmd (Report isError msg) - - -- See Note [TH recover with -fexternal-interpreter] in GHC.Tc.Gen.Splice - qRecover (GHCiQ h) a = GHCiQ $ \sRef -> mask $ \unmask -> do - s <- readIORef sRef - remoteTHCall (qsPipe s) StartRecover - e <- try $ unmask $ runGHCiQ (a <* ghcCmd FailIfErrs) sRef - remoteTHCall (qsPipe s) (EndRecover (isLeft e)) - case e of - Left GHCiQException{} -> h sRef - Right r -> return r - qLookupName isType occ = ghcCmd (LookupName isType occ) - qReify name = ghcCmd (Reify name) - qReifyFixity name = ghcCmd (ReifyFixity name) - qReifyType name = ghcCmd (ReifyType name) - qReifyInstances name tys = ghcCmd (ReifyInstances name tys) - qReifyRoles name = ghcCmd (ReifyRoles name) - -- To reify annotations, we send GHC the AnnLookup and also the -- TypeRep of the thing we're looking for, to avoid needing to -- serialize irrelevant annotations. - qReifyAnnotations :: forall a . Data a => TH.AnnLookup -> GHCiQ [a] - qReifyAnnotations lookup = +reifyAnnotations :: forall a . Data a => TH.AnnLookup -> GHCiQ [a] +reifyAnnotations lookup = map (deserializeWithData . B.unpack) <$> ghcCmd (ReifyAnnotations lookup typerep) where typerep = typeOf (undefined :: a) - qReifyModule m = ghcCmd (ReifyModule m) - qReifyConStrictness name = ghcCmd (ReifyConStrictness name) - qLocation = fromMaybe noLoc . qsLocation <$> getState - qGetPackageRoot = ghcCmd GetPackageRoot - qAddDependentFile file = ghcCmd (AddDependentFile file) - qAddDependentDirectory dir = ghcCmd (AddDependentDirectory dir) - qAddTempFile suffix = ghcCmd (AddTempFile suffix) - qAddTopDecls decls = ghcCmd (AddTopDecls decls) - qAddForeignFilePath lang fp = ghcCmd (AddForeignFilePath lang fp) - qAddModFinalizer fin = GHCiQ (\_ -> mkRemoteRef fin) >>= +runQinGHCiQ :: TH.Q a -> GHCiQ a +runQinGHCiQ (TH.Q m) = GHCiQ $ \sRef -> m (metaHandlersGHCiQ (runInIO sRef)) + where + runInIO :: IORef QState -> GHCiQ a -> IO a + runInIO sRef (GHCiQ m) = m sRef + +metaHandlersGHCiQ :: (forall x. GHCiQ x -> IO x) -> TH.MetaHandlers IO +metaHandlersGHCiQ runInIO = TH.MetaHandlers { + mLiftIO = id + , mFail = runInIO . fail + , mNewName = \str -> runInIO $ ghcCmd (NewName str) + , mReport = \isError msg -> runInIO $ ghcCmd (Report isError msg) + + -- See Note [TH recover with -fexternal-interpreter] in GHC.Tc.Gen.Splice + , mRecover = \h a -> runInIO $ GHCiQ $ \sRef -> mask $ \unmask -> do + s <- readIORef sRef + remoteTHCall (qsPipe s) StartRecover + e <- try $ unmask $ runGHCiQ (runQinGHCiQ a <* ghcCmd FailIfErrs) sRef + remoteTHCall (qsPipe s) (EndRecover (isLeft e)) + case e of + Left GHCiQException{} -> + runGHCiQ (runQinGHCiQ h) sRef + Right r -> return r + , mLookupName = \isType occ -> runInIO $ ghcCmd (LookupName isType occ) + , mReify = \name ->runInIO $ ghcCmd (Reify name) + , mReifyFixity = \name ->runInIO $ ghcCmd (ReifyFixity name) + , mReifyType = \name -> runInIO $ ghcCmd (ReifyType name) + , mReifyInstances = \name tys -> runInIO $ ghcCmd (ReifyInstances name tys) + , mReifyRoles = \name -> runInIO $ ghcCmd (ReifyRoles name) + + , mReifyAnnotations = runInIO . reifyAnnotations + , mReifyModule = \m -> runInIO $ ghcCmd (ReifyModule m) + , mReifyConStrictness = \name -> runInIO $ ghcCmd (ReifyConStrictness name) + , mLocation = runInIO $ fromMaybe noLoc . qsLocation <$> getState + , mGetPackageRoot = runInIO $ ghcCmd GetPackageRoot + , mAddDependentFile = \file -> runInIO $ ghcCmd (AddDependentFile file) + , mAddDependentDirectory = \dir -> runInIO $ ghcCmd (AddDependentDirectory dir) + , mAddTempFile = \suffix -> runInIO $ ghcCmd (AddTempFile suffix) + , mAddTopDecls = \decls -> runInIO $ ghcCmd (AddTopDecls decls) + , mAddForeignFilePath = \lang fp -> runInIO $ ghcCmd (AddForeignFilePath lang fp) + , mAddModFinalizer = \fin -> runInIO $ GHCiQ (\_ -> mkRemoteRef fin) >>= ghcCmd . AddModFinalizer - qAddCorePlugin str = ghcCmd (AddCorePlugin str) - qGetQ = do + , mAddCorePlugin = \str -> runInIO $ ghcCmd (AddCorePlugin str) + , mGetQ = runInIO $ do s <- getState let lookup :: forall a. Typeable a => Map TypeRep Dynamic -> Maybe a lookup m = fromDynamic =<< M.lookup (typeOf (undefined::a)) m return $ lookup (qsMap s) - qPutQ k = GHCiQ $ \sRef -> - modifyIORef' sRef (\s -> s { qsMap = M.insert (typeOf k) (toDyn k) (qsMap s) }) - qIsExtEnabled x = ghcCmd (IsExtEnabled x) - qExtsEnabled = ghcCmd ExtsEnabled - qPutDoc l s = ghcCmd (PutDoc l s) - qGetDoc l = ghcCmd (GetDoc l) + , mPutQ = \k -> runInIO $ GHCiQ $ \sRef -> + modifyIORef' sRef (\s -> s { qsMap = M.insert (typeOf k) (toDyn k) (qsMap s) }) + , mIsExtEnabled = \x -> runInIO $ ghcCmd (IsExtEnabled x) + , mExtsEnabled = runInIO $ ghcCmd ExtsEnabled + , mPutDoc = \l s -> runInIO $ ghcCmd (PutDoc l s) + , mGetDoc = \l -> runInIO $ ghcCmd (GetDoc l) +} -- | The implementation of the 'StartTH' message: create -- a new IORef QState, and return a RemoteRef to it. @@ -235,7 +247,7 @@ runModFinalizerRefs pipe rstate qrefs = do qstateref <- localRef rstate qstate <- readIORef qstateref qstate' <- newIORef $ qstate { qsPipe = pipe } - _ <- runGHCiQ (TH.runQ $ sequence_ qs) qstate' + _ <- runGHCiQ (runQinGHCiQ $ sequence_ qs) qstate' return () -- | The implementation of the 'RunTH' message @@ -272,5 +284,5 @@ runTHQ runTHQ pipe rstate mb_loc ghciq = do qstateref <- localRef rstate modifyIORef' qstateref (\qstate -> qstate { qsLocation = mb_loc, qsPipe = pipe }) - r <- runGHCiQ (TH.runQ ghciq) qstateref + r <- runGHCiQ (runQinGHCiQ ghciq) qstateref return $! LB.toStrict (runPut (put r)) ===================================== libraries/template-haskell/Language/Haskell/TH/Syntax.hs ===================================== @@ -11,7 +11,9 @@ module Language.Haskell.TH.Syntax ( Exp (..), Match (..), Clause (..), - Q (..), + Q, + -- backwards compatibility + Language.Haskell.TH.Syntax.unQ, Pat (..), Stmt (..), Con (..), @@ -207,6 +209,8 @@ import System.FilePath import Data.Data hiding (Fixity(..)) import Data.List.NonEmpty (NonEmpty(..)) import GHC.Lexeme ( startsVarSym, startsVarId ) +import Control.Monad.IO.Class (MonadIO, liftIO) +import System.IO (hPutStrLn, stderr) -- This module completely re-exports 'GHC.Boot.TH.Syntax', -- and exports additionally functions that depend on @filepath@ or @System.IO@. @@ -499,3 +503,180 @@ reassociate the tree as necessary. -- Subsumed by the more general 'SpecialiseEP' constructor. pattern SpecialiseP :: Name -> Type -> (Maybe Inline) -> Phases -> Pragma pattern SpecialiseP nm ty inl phases = SpecialiseEP Nothing [] (SigE (VarE nm) ty) inl phases + +unQ :: Q a -> (forall m. Quasi m => m a) +unQ m = runQ m + +----------------------------------------------------- +-- +-- The Quasi class +-- +----------------------------------------------------- + +class (MonadIO m, MonadFail m) => Quasi m where + qRunQ :: Q a -> m a + -- | Fresh names. See 'newName'. + qNewName :: String -> m Name + + ------- Error reporting and recovery ------- + -- | Report an error (True) or warning (False) + -- ...but carry on; use 'fail' to stop. See 'report'. + qReport :: Bool -> String -> m () + + -- | See 'recover'. + qRecover :: m a -- ^ the error handler + -> m a -- ^ action which may fail + -> m a -- ^ Recover from the monadic 'fail' + + ------- Inspect the type-checker's environment ------- + -- | True <=> type namespace, False <=> value namespace. See 'lookupName'. + qLookupName :: Bool -> String -> m (Maybe Name) + -- | See 'reify'. + qReify :: Name -> m Info + -- | See 'reifyFixity'. + qReifyFixity :: Name -> m (Maybe Fixity) + -- | See 'reifyType'. + qReifyType :: Name -> m Type + -- | Is (n tys) an instance? Returns list of matching instance Decs (with + -- empty sub-Decs) Works for classes and type functions. See 'reifyInstances'. + qReifyInstances :: Name -> [Type] -> m [Dec] + -- | See 'reifyRoles'. + qReifyRoles :: Name -> m [Role] + -- | See 'reifyAnnotations'. + qReifyAnnotations :: Data a => AnnLookup -> m [a] + -- | See 'reifyModule'. + qReifyModule :: Module -> m ModuleInfo + -- | See 'reifyConStrictness'. + qReifyConStrictness :: Name -> m [DecidedStrictness] + + -- | See 'location'. + qLocation :: m Loc + + -- | Input/output (dangerous). See 'runIO'. + qRunIO :: IO a -> m a + qRunIO = liftIO + -- | See 'getPackageRoot'. + qGetPackageRoot :: m FilePath + + -- | See 'addDependentFile'. + qAddDependentFile :: FilePath -> m () + + -- | See 'addDependentDirectory'. + qAddDependentDirectory :: FilePath -> m () + + -- | See 'addTempFile'. + qAddTempFile :: String -> m FilePath + + -- | See 'addTopDecls'. + qAddTopDecls :: [Dec] -> m () + + -- | See 'addForeignFilePath'. + qAddForeignFilePath :: ForeignSrcLang -> String -> m () + + -- | See 'addModFinalizer'. + qAddModFinalizer :: Q () -> m () + + -- | See 'addCorePlugin'. + qAddCorePlugin :: String -> m () + + -- | See 'getQ'. + qGetQ :: Typeable a => m (Maybe a) + + -- | See 'putQ'. + qPutQ :: Typeable a => a -> m () + + -- | See 'isExtEnabled'. + qIsExtEnabled :: Extension -> m Bool + -- | See 'extsEnabled'. + qExtsEnabled :: m [Extension] + + -- | See 'putDoc'. + qPutDoc :: DocLoc -> String -> m () + -- | See 'getDoc'. + qGetDoc :: DocLoc -> m (Maybe String) + +-- | \"Runs\" the 'Q' monad. Normal users of Template Haskell +-- should not need this function, as the splice brackets @$( ... )@ +-- are the usual way of running a 'Q' computation. +-- +-- This function is primarily used in GHC internals, and for debugging +-- splices by running them in 'IO'. +-- +-- Note that many functions in 'Q', such as 'reify' and other compiler +-- queries, are not supported when running 'Q' in 'IO'; these operations +-- simply fail at runtime. Indeed, the only operations guaranteed to succeed +-- are 'newName', 'runIO', 'reportError' and 'reportWarning'. +runQ :: Quasi m => Q a -> m a +runQ = qRunQ + +----------------------------------------------------- +-- The IO instance of Quasi +----------------------------------------------------- + +-- | This instance is used only when running a Q +-- computation in the IO monad, usually just to +-- print the result. There is no interesting +-- type environment, so reification isn't going to +-- work. +instance Quasi IO where + qRunQ (Q m) = m metaHandlersIO + qNewName = newNameIO + + qReport True msg = hPutStrLn stderr ("Template Haskell error: " ++ msg) + qReport False msg = hPutStrLn stderr ("Template Haskell error: " ++ msg) + + qLookupName _ _ = badIO "lookupName" + qReify _ = badIO "reify" + qReifyFixity _ = badIO "reifyFixity" + qReifyType _ = badIO "reifyFixity" + qReifyInstances _ _ = badIO "reifyInstances" + qReifyRoles _ = badIO "reifyRoles" + qReifyAnnotations _ = badIO "reifyAnnotations" + qReifyModule _ = badIO "reifyModule" + qReifyConStrictness _ = badIO "reifyConStrictness" + qLocation = badIO "currentLocation" + qRecover _ _ = badIO "recover" -- Maybe we could fix this? + qGetPackageRoot = badIO "getProjectRoot" + qAddDependentFile _ = badIO "addDependentFile" + qAddTempFile _ = badIO "addTempFile" + qAddTopDecls _ = badIO "addTopDecls" + qAddForeignFilePath _ _ = badIO "addForeignFilePath" + qAddModFinalizer _ = badIO "addModFinalizer" + qAddCorePlugin _ = badIO "addCorePlugin" + qGetQ = badIO "getQ" + qPutQ _ = badIO "putQ" + qIsExtEnabled _ = badIO "isExtEnabled" + qExtsEnabled = badIO "extsEnabled" + qPutDoc _ _ = badIO "putDoc" + qGetDoc _ = badIO "getDoc" + qAddDependentDirectory _ = badIO "AddDependentDirectory" + +instance Quasi Q where + qRunQ = id + qNewName = newName + qReport = report + qRecover = recover + qReify = reify + qReifyFixity = reifyFixity + qReifyType = reifyType + qReifyInstances = reifyInstances + qReifyRoles = reifyRoles + qReifyAnnotations = reifyAnnotations + qReifyModule = reifyModule + qReifyConStrictness = reifyConStrictness + qLookupName = lookupName + qLocation = location + qGetPackageRoot = getPackageRoot + qAddDependentFile = addDependentFile + qAddDependentDirectory = addDependentDirectory + qAddTempFile = addTempFile + qAddTopDecls = addTopDecls + qAddForeignFilePath = addForeignFilePath + qAddModFinalizer = addModFinalizer + qAddCorePlugin = addCorePlugin + qGetQ = getQ + qPutQ = putQ + qIsExtEnabled = isExtEnabled + qExtsEnabled = extsEnabled + qPutDoc = putDoc + qGetDoc = getDoc ===================================== testsuite/tests/interface-stability/template-haskell-exports.stdout ===================================== @@ -354,7 +354,6 @@ module Language.Haskell.TH where type Pred = Type type PredQ :: * type PredQ = Q Pred - type role Q nominal type Q :: * -> * newtype Q a = ... type Quote :: (* -> *) -> Constraint @@ -655,7 +654,7 @@ module Language.Haskell.TH where roleAnnotD :: forall (m :: * -> *). Quote m => Name -> [GHC.Internal.TH.Lib.Role] -> m Dec ruleVar :: forall (m :: * -> *). Quote m => Name -> m RuleBndr runIO :: forall a. GHC.Internal.Types.IO a -> Q a - runQ :: forall (m :: * -> *) a. GHC.Internal.TH.Monad.Quasi m => Q a -> m a + runQ :: forall (m :: * -> *) a. Language.Haskell.TH.Syntax.Quasi m => Q a -> m a safe :: Safety sectionL :: forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp sectionR :: forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp @@ -1703,11 +1702,11 @@ module Language.Haskell.TH.Syntax where data Pragma = InlineP Name Inline RuleMatch Phases | OpaqueP Name | SpecialiseEP (GHC.Internal.Maybe.Maybe [TyVarBndr ()]) [RuleBndr] Exp (GHC.Internal.Maybe.Maybe Inline) Phases | SpecialiseInstP Type | RuleP GHC.Internal.Base.String (GHC.Internal.Maybe.Maybe [TyVarBndr ()]) [RuleBndr] Exp Exp Phases | AnnP AnnTarget Exp | LineP GHC.Internal.Types.Int GHC.Internal.Base.String | CompleteP [Name] (GHC.Internal.Maybe.Maybe Name) | SCCP Name (GHC.Internal.Maybe.Maybe GHC.Internal.Base.String) type Pred :: * type Pred = Type - type role Q nominal type Q :: * -> * - newtype Q a = Q {unQ :: forall (m :: * -> *). Quasi m => m a} + newtype Q a = ... type Quasi :: (* -> *) -> Constraint class (GHC.Internal.Control.Monad.IO.Class.MonadIO m, GHC.Internal.Control.Monad.Fail.MonadFail m) => Quasi m where + qRunQ :: forall a. Q a -> m a qNewName :: GHC.Internal.Base.String -> m Name qReport :: GHC.Internal.Types.Bool -> GHC.Internal.Base.String -> m () qRecover :: forall a. m a -> m a -> m a @@ -1730,13 +1729,13 @@ module Language.Haskell.TH.Syntax where qAddForeignFilePath :: ForeignSrcLang -> GHC.Internal.Base.String -> m () qAddModFinalizer :: Q () -> m () qAddCorePlugin :: GHC.Internal.Base.String -> m () - qGetQ :: forall a. ghc-internal-9.1500.0:GHC.Internal.Data.Typeable.Internal.Typeable a => m (GHC.Internal.Maybe.Maybe a) - qPutQ :: forall a. ghc-internal-9.1500.0:GHC.Internal.Data.Typeable.Internal.Typeable a => a -> m () + qGetQ :: forall a. ghc-internal-10.100.0:GHC.Internal.Data.Typeable.Internal.Typeable a => m (GHC.Internal.Maybe.Maybe a) + qPutQ :: forall a. ghc-internal-10.100.0:GHC.Internal.Data.Typeable.Internal.Typeable a => a -> m () qIsExtEnabled :: Extension -> m GHC.Internal.Types.Bool qExtsEnabled :: m [Extension] qPutDoc :: DocLoc -> GHC.Internal.Base.String -> m () qGetDoc :: DocLoc -> m (GHC.Internal.Maybe.Maybe GHC.Internal.Base.String) - {-# MINIMAL qNewName, qReport, qRecover, qLookupName, qReify, qReifyFixity, qReifyType, qReifyInstances, qReifyRoles, qReifyAnnotations, qReifyModule, qReifyConStrictness, qLocation, qGetPackageRoot, qAddDependentFile, qAddDependentDirectory, qAddTempFile, qAddTopDecls, qAddForeignFilePath, qAddModFinalizer, qAddCorePlugin, qGetQ, qPutQ, qIsExtEnabled, qExtsEnabled, qPutDoc, qGetDoc #-} + {-# MINIMAL qRunQ, qNewName, qReport, qRecover, qLookupName, qReify, qReifyFixity, qReifyType, qReifyInstances, qReifyRoles, qReifyAnnotations, qReifyModule, qReifyConStrictness, qLocation, qGetPackageRoot, qAddDependentFile, qAddDependentDirectory, qAddTempFile, qAddTopDecls, qAddForeignFilePath, qAddModFinalizer, qAddCorePlugin, qGetQ, qPutQ, qIsExtEnabled, qExtsEnabled, qPutDoc, qGetDoc #-} type Quote :: (* -> *) -> Constraint class GHC.Internal.Base.Monad m => Quote m where newName :: GHC.Internal.Base.String -> m Name @@ -1814,7 +1813,7 @@ module Language.Haskell.TH.Syntax where falseName :: Name getDoc :: DocLoc -> Q (GHC.Internal.Maybe.Maybe GHC.Internal.Base.String) getPackageRoot :: Q GHC.Internal.IO.FilePath - getQ :: forall a. ghc-internal-9.1500.0:GHC.Internal.Data.Typeable.Internal.Typeable a => Q (GHC.Internal.Maybe.Maybe a) + getQ :: forall a. ghc-internal-10.100.0:GHC.Internal.Data.Typeable.Internal.Typeable a => Q (GHC.Internal.Maybe.Maybe a) get_cons_names :: Con -> [Name] hoistCode :: forall (m :: * -> *) (n :: * -> *) (r :: GHC.Internal.Types.RuntimeRep) (a :: TYPE r). GHC.Internal.Base.Monad m => (forall x. m x -> n x) -> Code m a -> Code n a isExtEnabled :: Extension -> Q GHC.Internal.Types.Bool @@ -1861,7 +1860,7 @@ module Language.Haskell.TH.Syntax where oneName :: Name pkgString :: PkgName -> GHC.Internal.Base.String putDoc :: DocLoc -> GHC.Internal.Base.String -> Q () - putQ :: forall a. ghc-internal-9.1500.0:GHC.Internal.Data.Typeable.Internal.Typeable a => a -> Q () + putQ :: forall a. ghc-internal-10.100.0:GHC.Internal.Data.Typeable.Internal.Typeable a => a -> Q () recover :: forall a. Q a -> Q a -> Q a reify :: Name -> Q Info reifyAnnotations :: forall a. GHC.Internal.Data.Data.Data a => AnnLookup -> Q [a] @@ -1884,6 +1883,7 @@ module Language.Haskell.TH.Syntax where trueName :: Name tupleDataName :: GHC.Internal.Types.Int -> Name tupleTypeName :: GHC.Internal.Types.Int -> Name + unQ :: forall a. Q a -> forall (m :: * -> *). Quasi m => m a unTypeCode :: forall (r :: GHC.Internal.Types.RuntimeRep) (a :: TYPE r) (m :: * -> *). Quote m => Code m a -> m Exp unTypeQ :: forall (r :: GHC.Internal.Types.RuntimeRep) (a :: TYPE r) (m :: * -> *). Quote m => m (TExp a) -> m Exp unboxedSumDataName :: SumAlt -> SumArity -> Name @@ -2289,10 +2289,10 @@ instance forall a b c d e f g. (GHC.Internal.TH.Lift.Lift a, GHC.Internal.TH.Lif instance GHC.Internal.TH.Lift.Lift (# #) -- Defined in ‘GHC.Internal.TH.Lift’ instance GHC.Internal.TH.Lift.Lift GHC.Internal.Prim.Char# -- Defined in ‘GHC.Internal.TH.Lift’ instance GHC.Internal.TH.Lift.Lift GHC.Internal.Prim.Word# -- Defined in ‘GHC.Internal.TH.Lift’ -instance GHC.Internal.TH.Monad.Quasi GHC.Internal.Types.IO -- Defined in ‘GHC.Internal.TH.Monad’ -instance GHC.Internal.TH.Monad.Quasi GHC.Internal.TH.Monad.Q -- Defined in ‘GHC.Internal.TH.Monad’ instance GHC.Internal.TH.Monad.Quote GHC.Internal.Types.IO -- Defined in ‘GHC.Internal.TH.Monad’ instance GHC.Internal.TH.Monad.Quote GHC.Internal.TH.Monad.Q -- Defined in ‘GHC.Internal.TH.Monad’ instance [safe] Language.Haskell.TH.Lib.DefaultBndrFlag GHC.Internal.TH.Syntax.BndrVis -- Defined in ‘Language.Haskell.TH.Lib’ instance [safe] Language.Haskell.TH.Lib.DefaultBndrFlag GHC.Internal.TH.Syntax.Specificity -- Defined in ‘Language.Haskell.TH.Lib’ instance [safe] Language.Haskell.TH.Lib.DefaultBndrFlag () -- Defined in ‘Language.Haskell.TH.Lib’ +instance Language.Haskell.TH.Syntax.Quasi GHC.Internal.Types.IO -- Defined in ‘Language.Haskell.TH.Syntax’ +instance Language.Haskell.TH.Syntax.Quasi GHC.Internal.TH.Monad.Q -- Defined in ‘Language.Haskell.TH.Syntax’ View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/44cc53feef363e4beeb5f3d70e008a62... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/44cc53feef363e4beeb5f3d70e008a62... 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