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[Git][ghc/ghc][wip/T25440] Wibbles
by Simon Peyton Jones (＠simonpj) 18 Apr '25

18 Apr '25

Simon Peyton Jones pushed to branch wip/T25440 at Glasgow Haskell Compiler / GHC Commits: be011dac by Simon Peyton Jones at 2025-04-18T13:12:23+01:00 Wibbles - - - - - 12 changed files: - compiler/GHC/Tc/Errors.hs - compiler/GHC/Tc/Solver/Default.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/Types/Constraint.hs - compiler/GHC/Tc/Utils/TcMType.hs - compiler/GHC/Tc/Zonk/TcType.hs - compiler/GHC/Tc/Zonk/Type.hs - testsuite/tests/indexed-types/should_fail/T3330c.stderr - testsuite/tests/indexed-types/should_fail/T4174.stderr - testsuite/tests/indexed-types/should_fail/T8227.stderr - testsuite/tests/typecheck/should_fail/T18851.stderr Changes: ===================================== compiler/GHC/Tc/Errors.hs ===================================== @@ -466,13 +466,12 @@ mkErrorItem ct = do { let loc = ctLoc ct flav = ctFlavour ct - ; (suppress, m_evdest) <- case ctEvidence ct of - -- For this `suppress` stuff - -- see Note [Wanteds rewrite Wanteds] in GHC.Tc.Types.Constraint - CtGiven {} -> return (False, Nothing) - CtWanted (WantedCt { ctev_rewriters = rewriters, ctev_dest = dest }) - -> do { rewriters' <- zonkRewriterSet rewriters - ; return (not (isEmptyRewriterSet rewriters'), Just dest) } + (suppress, m_evdest) = case ctEvidence ct of + -- For this `suppress` stuff + -- see Note [Wanteds rewrite Wanteds] in GHC.Tc.Types.Constraint + CtGiven {} -> (False, Nothing) + CtWanted (WantedCt { ctev_rewriters = rws, ctev_dest = dest }) + -> (not (isEmptyRewriterSet rws), Just dest) ; let m_reason = case ct of CIrredCan (IrredCt { ir_reason = reason }) -> Just reason @@ -503,7 +502,7 @@ reportWanteds ctxt tc_lvl wc@(WC { wc_simple = simples, wc_impl = implics , text "tidy_errs =" <+> ppr tidy_errs ]) -- Catch an awkward (and probably rare) case in which /all/ errors are - -- suppressed: see Wrinkle (WRW2) in Note [Prioritise Wanteds with empty + -- suppressed: see Wrinkle (PER2) in Note [Prioritise Wanteds with empty -- RewriterSet] in GHC.Tc.Types.Constraint. -- -- Unless we are sure that an error will be reported some other way ===================================== compiler/GHC/Tc/Solver/Default.hs ===================================== @@ -1081,9 +1081,9 @@ disambigProposalSequences orig_wanteds wanteds proposalSequences allConsistent ; successes <- fmap catMaybes $ nestImplicTcS fake_ev_binds_var (pushTcLevel tclvl) $ mapM firstSuccess proposalSequences - ; traceTcS "disambigProposalSequences" (vcat [ ppr wanteds - , ppr proposalSequences - , ppr successes ]) + ; traceTcS "disambigProposalSequences {" (vcat [ ppr wanteds + , ppr proposalSequences + , ppr successes ]) -- Step (4) in Note [How type-class constraints are defaulted] ; case successes of success@(tvs, subst) : rest ===================================== compiler/GHC/Tc/Solver/Equality.hs ===================================== @@ -2077,11 +2077,15 @@ Wrinkles: that `kw`. (EIK2a) We must later indeed unify if/when the kind-level wanted, `kw` gets - solved. This is done in kickOutAfterFillingCoercionHole, which kicks out + solved. This is done in `kickOutAfterFillingCoercionHole`, which kicks out all equalities whose RHS mentions the filled-in coercion hole. Note that it looks for type family equalities, too, because of the use of unifyTest in canEqTyVarFunEq. + To do this, we slightly-hackily use the `ctev_rewriters` field of the inert, + which records that `w` has been rewritten by `kw`. + See (WRW3) in Note [Wanteds reewrite Wanteds] in GHC.Tc.Types.Constraint. + (EIK2b) What if the RHS mentions /other/ coercion holes? How can that happen? The main way is like this. Assume F :: forall k. k -> Type [W] kw : k ~ Type @@ -2615,6 +2619,7 @@ But it's not so simple: error message that we can solve (F a ~ a Int) arising from F a ~ F a Better to hang on to `g1`, in preference to `g2`. + See (WRW1) in Note [Wanteds rewrite Wanteds] in GHC.Tc.Types.Constraint. -} tryInertEqs :: EqCt -> SolverStage () ===================================== compiler/GHC/Tc/Solver/Monad.hs ===================================== @@ -150,7 +150,6 @@ import qualified GHC.Tc.Utils.Env as TcM , topIdLvl ) import GHC.Tc.Zonk.Monad ( ZonkM ) import qualified GHC.Tc.Zonk.TcType as TcM -import qualified GHC.Tc.Zonk.Type as TcM import GHC.Driver.DynFlags @@ -489,7 +488,7 @@ kickOutAfterFillingCoercionHole hole kick_out ics@(IC { inert_irreds = irreds }) = -- We only care about irreds here, because any constraint blocked -- by a coercion hole is an irred. See wrinkle (EIK2a) in - -- Note [Equalities with incompatible kinds] in GHC.Tc.Solver.Canonical + -- Note [Equalities with incompatible kinds] in GHC.Tc.Solver.Equality (irreds_to_kick, ics { inert_irreds = irreds_to_keep }) where (irreds_to_kick, irreds_to_keep) = partitionBag kick_ct irreds @@ -1457,8 +1456,8 @@ emitWork cts -- c1 is rewritten by another, c2. When c2 gets solved, -- c1 has no rewriters, and can be prioritised; see -- Note [Prioritise Wanteds with empty RewriterSet] - -- in GHC.Tc.Types.Constraint wrinkle (WRW1) - ; cts <- wrapTcS $ mapBagM TcM.zonkCtRewriterSet cts + -- in GHC.Tc.Types.Constraint wrinkle (PER1) + ; cts <- liftZonkTcS $ mapBagM TcM.zonkCtRewriterSet cts ; updWorkListTcS (extendWorkListCts cts) } emitImplication :: Implication -> TcS () @@ -2252,7 +2251,7 @@ wrapUnifierX ev role do_unifications ; wrapTcS $ do { defer_ref <- TcM.newTcRef emptyBag ; unified_ref <- TcM.newTcRef [] - ; rewriters <- TcM.zonkRewriterSet (ctEvRewriters ev) + ; rewriters <- TcM.liftZonkM (TcM.zonkRewriterSet (ctEvRewriters ev)) ; let env = UE { u_role = role , u_rewriters = rewriters , u_loc = ctEvLoc ev ===================================== compiler/GHC/Tc/Types/Constraint.hs ===================================== @@ -240,7 +240,7 @@ instance Outputable DictCt where {- Note [Canonical equalities] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ An EqCt is a canonical equality constraint, one that can live in the inert set, -and that can be used to rewrite other constrtaints. It satisfies these invariants: +and that can be used to rewrite other constraints. It satisfies these invariants: * (TyEq:OC) lhs does not occur in rhs (occurs check) Note [EqCt occurs check] * (TyEq:F) rhs has no foralls @@ -2444,19 +2444,29 @@ We thus want Wanteds to rewrite Wanteds in order to accept more programs, but we don't want Wanteds to rewrite Wanteds because doing so can create inscrutable error messages. To solve this dilemma: -* We allow Wanteds to rewrite Wanteds, but... +* We allow Wanteds to rewrite Wanteds, but each Wanted tracks the set of Wanteds + it has been rewritten by, in its RewriterSet, stored in the ctev_rewriters + field of the CtWanted constructor of CtEvidence. (Only Wanteds have + RewriterSets.) -* Each Wanted tracks the set of Wanteds it has been rewritten by, in its - RewriterSet, stored in the ctev_rewriters field of the CtWanted - constructor of CtEvidence. (Only Wanteds have RewriterSets.) +* A RewriterSet is just a set of unfilled CoercionHoles. This is sufficient + because only equalities (evidenced by coercion holes) are used for rewriting; + other (dictionary) constraints cannot ever rewrite. + +* The rewriter (in e.g. GHC.Tc.Solver.Rewrite.rewrite) tracks and returns a RewriterSet, + consisting of the evidence (a CoercionHole) for any Wanted equalities used in + rewriting. + +* Then GHC.Tc.Solver.Solve.rewriteEvidence and GHC.Tc.Solver.Equality.rewriteEqEvidence + add this RewriterSet to the rewritten constraint's rewriter set. * In error reporting, we simply suppress any errors that have been rewritten by /unsolved/ wanteds. This suppression happens in GHC.Tc.Errors.mkErrorItem, - which uses GHC.Tc.Zonk.Type.zonkRewriterSet to look through any filled + which uses `GHC.Tc.Zonk.Type.zonkRewriterSet` to look through any filled coercion holes. The idea is that we wish to report the "root cause" -- the error that rewrote all the others. -* We prioritise Wanteds that have an empty RewriterSet: +* In error reporting, we prioritise Wanteds that have an empty RewriterSet: see Note [Prioritise Wanteds with empty RewriterSet]. Let's continue our first example above: @@ -2471,19 +2481,30 @@ Because Wanteds can rewrite Wanteds, w1 will rewrite w2, yielding The {w1} in the second line of output is the RewriterSet of w1. -A RewriterSet is just a set of unfilled CoercionHoles. This is sufficient -because only equalities (evidenced by coercion holes) are used for rewriting; -other (dictionary) constraints cannot ever rewrite. The rewriter (in -e.g. GHC.Tc.Solver.Rewrite.rewrite) tracks and returns a RewriterSet, -consisting of the evidence (a CoercionHole) for any Wanted equalities used in -rewriting. Then GHC.Tc.Solver.Solve.rewriteEvidence and -GHC.Tc.Solver.Equality.rewriteEqEvidence add this RewriterSet to the rewritten -constraint's rewriter set. +Wrinkles: + +(WRW1) When we find a constraint identical to one already in the inert set, + we solve one from the other. Other things being equal, keep the one + that has fewer (better still no) rewriters. + See (CE4) in Note [Combining equalities] in GHC.Tc.Solver.Equality. + + To this accurately we should use `zonkRewriterSet` during canonicalisation, + to eliminate rewriters that have now been solved. Currently we only do so + during error reporting; but perhaps we should change that. + +(WRW2) When zonk a constraint (with `zonkCt` and `zonkCtEvidence`) we take + the opportunity to zonk its `RewriterSet, which eliminates solved ones`. + This doesn't guarantee that rewriter sets are always up to date -- see + (WRW1) -- but it helps, and it de-clutters debug output. + +(WRW3) We use the rewriter set for a slightly different purpose, in (EIK2) + of Note [Equalities with incompatible kinds] in GHC.Tc.Solver.Equality. + This is a bit of a hack. Note [Prioritise Wanteds with empty RewriterSet] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When extending the WorkList, in GHC.Tc.Solver.InertSet.extendWorkListEq, -we priorities constraints that have no rewriters. Here's why. +we prioritise constraints that have no rewriters. Here's why. Consider this, which came up in T22793: inert: {} @@ -2527,11 +2548,11 @@ GHC.Tc.Solver.InertSet.extendWorkListEq, and extendWorkListEqs. Wrinkles -(WRW1) Before checking for an empty RewriterSet, we zonk the RewriterSet, +(PER1) Before checking for an empty RewriterSet, we zonk the RewriterSet, because some of those CoercionHoles may have been filled in since we last looked: see GHC.Tc.Solver.Monad.emitWork. -(WRW2) Despite the prioritisation, it is hard to be /certain/ that we can't end up +(PER2) Despite the prioritisation, it is hard to be /certain/ that we can't end up in a situation where all of the Wanteds have rewritten each other. In order to report /some/ error in this case, we simply report all the Wanteds. The user will get a perhaps-confusing error message, but they've ===================================== compiler/GHC/Tc/Utils/TcMType.hs ===================================== @@ -49,7 +49,6 @@ module GHC.Tc.Utils.TcMType ( newCoercionHole, newCoercionHoleO, newVanillaCoercionHole, fillCoercionHole, isFilledCoercionHole, - unpackCoercionHole, unpackCoercionHole_maybe, checkCoercionHole, newImplication, @@ -115,7 +114,6 @@ import GHC.Tc.Types.CtLoc( CtLoc, ctLocOrigin ) import GHC.Tc.Utils.Monad -- TcType, amongst others import GHC.Tc.Utils.TcType import GHC.Tc.Errors.Types -import GHC.Tc.Zonk.Type import GHC.Tc.Zonk.TcType import GHC.Builtin.Names @@ -1583,7 +1581,7 @@ collect_cand_qtvs_co orig_ty cur_lvl bound = go_co go_co dv (SubCo co) = go_co dv co go_co dv (HoleCo hole) - = do m_co <- unpackCoercionHole_maybe hole + = do m_co <- liftZonkM (unpackCoercionHole_maybe hole) case m_co of Just co -> go_co dv co Nothing -> go_cv dv (coHoleCoVar hole) ===================================== compiler/GHC/Tc/Zonk/TcType.hs ===================================== @@ -1,3 +1,5 @@ +{-# LANGUAGE DuplicateRecordFields #-} + {- (c) The University of Glasgow 2006 (c) The AQUA Project, Glasgow University, 1996-1998 @@ -36,6 +38,13 @@ module GHC.Tc.Zonk.TcType -- ** Zonking constraints , zonkCt, zonkWC, zonkSimples, zonkImplication + -- * Rewriter sets + , zonkRewriterSet, zonkCtRewriterSet, zonkCtEvRewriterSet + + -- * Coercion holes + , isFilledCoercionHole, unpackCoercionHole, unpackCoercionHole_maybe + + -- * Tidying , tcInitTidyEnv, tcInitOpenTidyEnv , tidyCt, tidyEvVar, tidyDelayedError @@ -81,7 +90,7 @@ import GHC.Core.Coercion import GHC.Core.Predicate import GHC.Utils.Constants -import GHC.Utils.Outputable +import GHC.Utils.Outputable as Outputable import GHC.Utils.Misc import GHC.Utils.Monad ( mapAccumLM ) import GHC.Utils.Panic @@ -89,6 +98,9 @@ import GHC.Utils.Panic import GHC.Data.Bag import GHC.Data.Pair +import Data.Semigroup +import Data.Maybe + {- ********************************************************************* * * Writing to metavariables @@ -366,8 +378,8 @@ checkCoercionHole cv co ; return $ assertPpr (ok cv_ty) (text "Bad coercion hole" <+> - ppr cv <> colon <+> vcat [ ppr t1, ppr t2, ppr role - , ppr cv_ty ]) + ppr cv Outputable.<> colon + <+> vcat [ ppr t1, ppr t2, ppr role, ppr cv_ty ]) co } | otherwise = return co @@ -494,9 +506,15 @@ zonkCt ct ; return (mkNonCanonical fl') } zonkCtEvidence :: CtEvidence -> ZonkM CtEvidence -zonkCtEvidence ctev - = do { pred' <- zonkTcType (ctEvPred ctev) - ; return (setCtEvPredType ctev pred') } +-- Zonks the ctev_pred and the ctev_rewriters; but not ctev_evar +-- For ctev_rewriters, see (WRW2) in Note [Wanteds rewrite Wanteds] +zonkCtEvidence (CtGiven (GivenCt { ctev_pred = pred, ctev_evar = var, ctev_loc = loc })) + = do { pred' <- zonkTcType pred + ; return (CtGiven (GivenCt { ctev_pred = pred', ctev_evar = var, ctev_loc = loc })) } +zonkCtEvidence (CtWanted wanted@(WantedCt { ctev_pred = pred, ctev_rewriters = rws })) + = do { pred' <- zonkTcType pred + ; rws' <- zonkRewriterSet rws + ; return (CtWanted (wanted { ctev_pred = pred', ctev_rewriters = rws' })) } zonkSkolemInfo :: SkolemInfo -> ZonkM SkolemInfo zonkSkolemInfo (SkolemInfo u sk) = SkolemInfo u <$> zonkSkolemInfoAnon sk @@ -530,6 +548,103 @@ win. But c.f Note [Sharing when zonking to Type] in GHC.Tc.Zonk.Type. +%************************************************************************ +%* * + Zonking rewriter sets +* * +************************************************************************ +-} + +zonkCtRewriterSet :: Ct -> ZonkM Ct +zonkCtRewriterSet ct + | isGivenCt ct + = return ct + | otherwise + = case ct of + CEqCan eq@(EqCt { eq_ev = ev }) -> do { ev' <- zonkCtEvRewriterSet ev + ; return (CEqCan (eq { eq_ev = ev' })) } + CIrredCan ir@(IrredCt { ir_ev = ev }) -> do { ev' <- zonkCtEvRewriterSet ev + ; return (CIrredCan (ir { ir_ev = ev' })) } + CDictCan di@(DictCt { di_ev = ev }) -> do { ev' <- zonkCtEvRewriterSet ev + ; return (CDictCan (di { di_ev = ev' })) } + CQuantCan {} -> return ct + CNonCanonical ev -> do { ev' <- zonkCtEvRewriterSet ev + ; return (CNonCanonical ev') } + +zonkCtEvRewriterSet :: CtEvidence -> ZonkM CtEvidence +zonkCtEvRewriterSet ev@(CtGiven {}) + = return ev +zonkCtEvRewriterSet ev@(CtWanted wtd) + = do { rewriters' <- zonkRewriterSet (ctEvRewriters ev) + ; return (CtWanted $ setWantedCtEvRewriters wtd rewriters') } + +-- | Check whether any coercion hole in a RewriterSet is still unsolved. +-- Does this by recursively looking through filled coercion holes until +-- one is found that is not yet filled in, at which point this aborts. +zonkRewriterSet :: RewriterSet -> ZonkM RewriterSet +zonkRewriterSet (RewriterSet set) + = nonDetStrictFoldUniqSet go (return emptyRewriterSet) set + -- this does not introduce non-determinism, because the only + -- monadic action is to read, and the combining function is + -- commutative + where + go :: CoercionHole -> ZonkM RewriterSet -> ZonkM RewriterSet + go hole m_acc = unionRewriterSet <$> check_hole hole <*> m_acc + + check_hole :: CoercionHole -> ZonkM RewriterSet + check_hole hole = do { m_co <- unpackCoercionHole_maybe hole + ; case m_co of + Nothing -> return (unitRewriterSet hole) + Just co -> unUCHM (check_co co) } + + check_ty :: Type -> UnfilledCoercionHoleMonoid + check_co :: Coercion -> UnfilledCoercionHoleMonoid + (check_ty, _, check_co, _) = foldTyCo folder () + + folder :: TyCoFolder () UnfilledCoercionHoleMonoid + folder = TyCoFolder { tcf_view = noView + , tcf_tyvar = \ _ tv -> check_ty (tyVarKind tv) + , tcf_covar = \ _ cv -> check_ty (varType cv) + , tcf_hole = \ _ -> UCHM . check_hole + , tcf_tycobinder = \ _ _ _ -> () } + +newtype UnfilledCoercionHoleMonoid = UCHM { unUCHM :: ZonkM RewriterSet } + +instance Semigroup UnfilledCoercionHoleMonoid where + UCHM l <> UCHM r = UCHM (unionRewriterSet <$> l <*> r) + +instance Monoid UnfilledCoercionHoleMonoid where + mempty = UCHM (return emptyRewriterSet) + + +{- +************************************************************************ +* * + Checking for coercion holes +* * +************************************************************************ +-} + +-- | Is a coercion hole filled in? +isFilledCoercionHole :: CoercionHole -> ZonkM Bool +isFilledCoercionHole (CoercionHole { ch_ref = ref }) + = isJust <$> readTcRef ref + +-- | Retrieve the contents of a coercion hole. Panics if the hole +-- is unfilled +unpackCoercionHole :: CoercionHole -> ZonkM Coercion +unpackCoercionHole hole + = do { contents <- unpackCoercionHole_maybe hole + ; case contents of + Just co -> return co + Nothing -> pprPanic "Unfilled coercion hole" (ppr hole) } + +-- | Retrieve the contents of a coercion hole, if it is filled +unpackCoercionHole_maybe :: CoercionHole -> ZonkM (Maybe Coercion) +unpackCoercionHole_maybe (CoercionHole { ch_ref = ref }) = readTcRef ref + + +{- %************************************************************************ %* * Tidying ===================================== compiler/GHC/Tc/Zonk/Type.hs ===================================== @@ -28,12 +28,6 @@ module GHC.Tc.Zonk.Type ( -- ** 'ZonkEnv', and the 'ZonkT' and 'ZonkBndrT' monad transformers module GHC.Tc.Zonk.Env, - -- * Coercion holes - isFilledCoercionHole, unpackCoercionHole, unpackCoercionHole_maybe, - - -- * Rewriter sets - zonkRewriterSet, zonkCtRewriterSet, zonkCtEvRewriterSet, - -- * Tidying tcInitTidyEnv, tcInitOpenTidyEnv, @@ -55,7 +49,6 @@ import GHC.Tc.TyCl.Build ( TcMethInfo, MethInfo ) import GHC.Tc.Utils.Env ( tcLookupGlobalOnly ) import GHC.Tc.Utils.TcType import GHC.Tc.Utils.Monad ( newZonkAnyType, setSrcSpanA, liftZonkM, traceTc, addErr ) -import GHC.Tc.Types.Constraint import GHC.Tc.Types.Evidence import GHC.Tc.Errors.Types import GHC.Tc.Zonk.Env @@ -88,7 +81,6 @@ import GHC.Types.Id import GHC.Types.TypeEnv import GHC.Types.Basic import GHC.Types.SrcLoc -import GHC.Types.Unique.Set import GHC.Types.Unique.FM import GHC.Types.TyThing @@ -99,7 +91,6 @@ import GHC.Data.Bag import Control.Monad import Control.Monad.Trans.Class ( lift ) -import Data.Semigroup import Data.List.NonEmpty ( NonEmpty ) import Data.Foldable ( toList ) @@ -1956,89 +1947,3 @@ finding the free type vars of an expression is necessarily monadic operation. (consider /\a -> f @ b, where b is side-effected to a) -} -{- -************************************************************************ -* * - Checking for coercion holes -* * -************************************************************************ --} - --- | Is a coercion hole filled in? -isFilledCoercionHole :: CoercionHole -> TcM Bool -isFilledCoercionHole (CoercionHole { ch_ref = ref }) - = isJust <$> readTcRef ref - --- | Retrieve the contents of a coercion hole. Panics if the hole --- is unfilled -unpackCoercionHole :: CoercionHole -> TcM Coercion -unpackCoercionHole hole - = do { contents <- unpackCoercionHole_maybe hole - ; case contents of - Just co -> return co - Nothing -> pprPanic "Unfilled coercion hole" (ppr hole) } - --- | Retrieve the contents of a coercion hole, if it is filled -unpackCoercionHole_maybe :: CoercionHole -> TcM (Maybe Coercion) -unpackCoercionHole_maybe (CoercionHole { ch_ref = ref }) = readTcRef ref - -zonkCtRewriterSet :: Ct -> TcM Ct -zonkCtRewriterSet ct - | isGivenCt ct - = return ct - | otherwise - = case ct of - CEqCan eq@(EqCt { eq_ev = ev }) -> do { ev' <- zonkCtEvRewriterSet ev - ; return (CEqCan (eq { eq_ev = ev' })) } - CIrredCan ir@(IrredCt { ir_ev = ev }) -> do { ev' <- zonkCtEvRewriterSet ev - ; return (CIrredCan (ir { ir_ev = ev' })) } - CDictCan di@(DictCt { di_ev = ev }) -> do { ev' <- zonkCtEvRewriterSet ev - ; return (CDictCan (di { di_ev = ev' })) } - CQuantCan {} -> return ct - CNonCanonical ev -> do { ev' <- zonkCtEvRewriterSet ev - ; return (CNonCanonical ev') } - -zonkCtEvRewriterSet :: CtEvidence -> TcM CtEvidence -zonkCtEvRewriterSet ev@(CtGiven {}) - = return ev -zonkCtEvRewriterSet ev@(CtWanted wtd) - = do { rewriters' <- zonkRewriterSet (ctEvRewriters ev) - ; return (CtWanted $ setWantedCtEvRewriters wtd rewriters') } - --- | Check whether any coercion hole in a RewriterSet is still unsolved. --- Does this by recursively looking through filled coercion holes until --- one is found that is not yet filled in, at which point this aborts. -zonkRewriterSet :: RewriterSet -> TcM RewriterSet -zonkRewriterSet (RewriterSet set) - = nonDetStrictFoldUniqSet go (return emptyRewriterSet) set - -- this does not introduce non-determinism, because the only - -- monadic action is to read, and the combining function is - -- commutative - where - go :: CoercionHole -> TcM RewriterSet -> TcM RewriterSet - go hole m_acc = unionRewriterSet <$> check_hole hole <*> m_acc - - check_hole :: CoercionHole -> TcM RewriterSet - check_hole hole = do { m_co <- unpackCoercionHole_maybe hole - ; case m_co of - Nothing -> return (unitRewriterSet hole) - Just co -> unUCHM (check_co co) } - - check_ty :: Type -> UnfilledCoercionHoleMonoid - check_co :: Coercion -> UnfilledCoercionHoleMonoid - (check_ty, _, check_co, _) = foldTyCo folder () - - folder :: TyCoFolder () UnfilledCoercionHoleMonoid - folder = TyCoFolder { tcf_view = noView - , tcf_tyvar = \ _ tv -> check_ty (tyVarKind tv) - , tcf_covar = \ _ cv -> check_ty (varType cv) - , tcf_hole = \ _ -> UCHM . check_hole - , tcf_tycobinder = \ _ _ _ -> () } - -newtype UnfilledCoercionHoleMonoid = UCHM { unUCHM :: TcM RewriterSet } - -instance Semigroup UnfilledCoercionHoleMonoid where - UCHM l <> UCHM r = UCHM (unionRewriterSet <$> l <*> r) - -instance Monoid UnfilledCoercionHoleMonoid where - mempty = UCHM (return emptyRewriterSet) ===================================== testsuite/tests/indexed-types/should_fail/T3330c.stderr ===================================== @@ -1,16 +1,24 @@ - -T3330c.hs:25:43: error: [GHC-18872] - • Couldn't match kind ‘* -> *’ with ‘*’ - When matching types - f1 :: * -> * - f1 x :: * - Expected: Der ((->) x) (Der f1 x) - Actual: R f1 - • In the first argument of ‘plug’, namely ‘rf’ +T3330c.hs:25:38: error: [GHC-25897] + • Could not deduce ‘Der f1 ~ f1’ + from the context: f ~ (f1 :+: g) + bound by a pattern with constructor: + RSum :: forall (f :: * -> *) (g :: * -> *). + R f -> R g -> R (f :+: g), + in an equation for ‘plug'’ + at T3330c.hs:25:8-17 + Expected: x -> f1 x + Actual: x -> Der f1 x + ‘f1’ is a rigid type variable bound by + a pattern with constructor: + RSum :: forall (f :: * -> *) (g :: * -> *). + R f -> R g -> R (f :+: g), + in an equation for ‘plug'’ + at T3330c.hs:25:8-17 + • The function ‘plug’ is applied to three visible arguments, + but its type ‘Rep f => Der f x -> x -> f x’ has only two In the first argument of ‘Inl’, namely ‘(plug rf df x)’ In the expression: Inl (plug rf df x) • Relevant bindings include - x :: x (bound at T3330c.hs:25:29) df :: Der f1 x (bound at T3330c.hs:25:25) rf :: R f1 (bound at T3330c.hs:25:13) - plug' :: R f -> Der f x -> x -> f x (bound at T3330c.hs:25:1) + ===================================== testsuite/tests/indexed-types/should_fail/T4174.stderr ===================================== @@ -1,6 +1,16 @@ - -T4174.hs:45:12: error: [GHC-18872] - • Couldn't match type ‘False’ with ‘True’ - arising from a use of ‘sync_large_objects’ +T4174.hs:45:12: error: [GHC-25897] + • Couldn't match type ‘a’ with ‘SmStep’ + Expected: m (Field (Way (GHC6'8 minor) n t p) a b) + Actual: m (Field (WayOf m) SmStep RtsSpinLock) + ‘a’ is a rigid type variable bound by + the type signature for: + testcase :: forall (m :: * -> *) minor n t p a b. + Monad m => + m (Field (Way (GHC6'8 minor) n t p) a b) + at T4174.hs:44:1-63 • In the expression: sync_large_objects In an equation for ‘testcase’: testcase = sync_large_objects + • Relevant bindings include + testcase :: m (Field (Way (GHC6'8 minor) n t p) a b) + (bound at T4174.hs:45:1) + ===================================== testsuite/tests/indexed-types/should_fail/T8227.stderr ===================================== @@ -13,12 +13,3 @@ T8227.hs:24:27: error: [GHC-83865] absoluteToParam :: Scalar (V a) -> a -> Scalar (V a) (bound at T8227.hs:24:1) -T8227.hs:24:48: error: [GHC-27958] - • Couldn't match type ‘p0’ with ‘Scalar (V p0)’ - arising from a type equality Scalar (V a) ~ Scalar (V p0) -> p0 - The type variable ‘p0’ is ambiguous - • In the second argument of ‘arcLengthToParam’, namely ‘eps’ - In the expression: arcLengthToParam eps eps - In an equation for ‘absoluteToParam’: - absoluteToParam eps seg = arcLengthToParam eps eps - ===================================== testsuite/tests/typecheck/should_fail/T18851.stderr ===================================== @@ -1,7 +1,7 @@ - T18851.hs:35:5: error: [GHC-18872] - • Couldn't match type ‘B’ with ‘A’ - arising from a superclass required to satisfy ‘C int0 A’, + • Couldn't match type ‘Bool’ with ‘B’ + arising from a superclass required to satisfy ‘C Int B’, arising from a use of ‘f’ • In the expression: f @A @B In an equation for ‘g’: g = f @A @B + View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/be011dacff5ef7a07d59ecd52ef5c6e… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/be011dacff5ef7a07d59ecd52ef5c6e… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/T25974
by Serge S. Gulin (＠gulin.serge) 18 Apr '25

18 Apr '25

Serge S. Gulin pushed new branch wip/T25974 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/T25974 You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Deleted branch wip/25974
by Serge S. Gulin (＠gulin.serge) 18 Apr '25

18 Apr '25

Serge S. Gulin deleted branch wip/25974 at Glasgow Haskell Compiler / GHC -- You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/25974
by Serge S. Gulin (＠gulin.serge) 18 Apr '25

18 Apr '25

Serge S. Gulin pushed new branch wip/25974 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/25974 You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Deleted branch wip/T24603-wine
by Serge S. Gulin (＠gulin.serge) 18 Apr '25

18 Apr '25

Serge S. Gulin deleted branch wip/T24603-wine at Glasgow Haskell Compiler / GHC -- You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/T24603-wine
by Serge S. Gulin (＠gulin.serge) 18 Apr '25

18 Apr '25

Serge S. Gulin pushed new branch wip/T24603-wine at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/T24603-wine You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T24603] 8 commits: Register EpToken in Parser.PostProcess.Haddock (#22558)
by Serge S. Gulin (＠gulin.serge) 18 Apr '25

18 Apr '25

Serge S. Gulin pushed to branch wip/T24603 at Glasgow Haskell Compiler / GHC Commits: 05eb50df by Vladislav Zavialov at 2025-04-13T19:16:38-04:00 Register EpToken in Parser.PostProcess.Haddock (#22558) This change allows us to reject more badly placed Haddock comments. Examples: module -- | Bad comment for the module T17544_kw where data Foo -- | Bad comment for MkFoo where MkFoo :: Foo newtype Bar -- | Bad comment for MkBar where MkBar :: () -> Bar class Cls a -- | Bad comment for clsmethod where clsmethod :: a - - - - - 01944e5e by Vladislav Zavialov at 2025-04-13T19:17:21-04:00 Reject puns in T2T (#24153) This patch implements pun detection in T2T. Consider: x = 42 f, g :: forall a -> ... f (type x) = g x In accordance with the specification, the `g x` function call is renamed as a term, so `x` refers to the top-level binding `x = 42`, not to the type variable binding `type x` as one might expect. This is somewhat counterintuitive because `g` expects a type argument. Forbidding puns in T2T allows us to produce a helpful error message: Test.hs:5:16: error: [GHC-09591] Illegal punned variable occurrence in a required type argument. The name ‘x’ could refer to: ‘x’ defined at Test.hs:3:1 ‘x’ bound at Test.hs:5:9 This commit is a follow up to 0dfb1fa799af254c8a1e1045fc3996af2d57a613 where checking for puns was left as future work. - - - - - cc580552 by Vladislav Zavialov at 2025-04-13T19:18:02-04:00 Additional test cases for #12088, #13790 Extract more test cases from ticket discussions, including multi-module examples. Follow up to 5712e0d646f611dfbfedfd7ef6dff3a18c016edb - - - - - d47bf776 by Matthew Pickering at 2025-04-14T16:44:41+01:00 driver: Use ModuleGraph for oneshot and --make mode This patch uses the `hsc_mod_graph` field for both oneshot and --make mode. Therefore, if part of the compiler requires usage of the module graph, you do so in a uniform way for the two different modes. The `ModuleGraph` describes the relationship between the modules in the home package and units in external packages. The `ModuleGraph` can be queried when information about the transitive closure of a package is needed. For example, the primary use of the ModuleGraph from within the compiler is in the loader, which needs to know the transitive closure of a module so it can load all the relevant objects for evaluation. In --make mode, downsweep computes the ModuleGraph before any compilation starts. In oneshot mode, a thunk is created at the start of compilation, which when forced will compute the module graph beneath the current module. The thunk is only forced at the moment when the user uses Template Haskell. Finally, there are some situations where we need to discover what dependencies to load but haven't loaded a module graph at all. In this case, there is a fallback which computes the transitive closure on the fly and doesn't cache the result. Presumably if you are going to call getLinkDeps a lot, you would compute the right ModuleGraph before you started. Importantly, this removes the ExternalModuleGraph abstraction. This was quite awkward to work with since it stored information about the home package inside the EPS. This patch will also be very useful when implementing explicit level imports, which requires more significant use of the module graph in order to determine which level instances are available at. Towards #25795 ------------------------- Metric Decrease: MultiLayerModulesTH_Make MultiLayerModulesTH_OneShot ------------------------- - - - - - 395e0ad1 by sheaf at 2025-04-16T12:33:26-04:00 base: remove .Internal modules (e.g. GHC.TypeLits) This commit removes the following internal modules from base, as per CLC proposal 217: - GHC.TypeNats.Internal - GHC.TypeLits.Internal - GHC.ExecutionStack.Internal Fixes #25007 - - - - - e0f3ff11 by Patrick at 2025-04-17T04:31:12-04:00 Refactor Handling of Multiple Default Declarations Fixes: #25912, #25914, #25934 Previously, GHC discarded all loaded defaults (tcg_default) when local defaults were encountered during typechecking. According to the exportable-named-default proposal (sections 2.4.2 and 2.4.3), local defaults should be merged into tcg_default, retaining any defaults already present while overriding where necessary. Key Changes: * Introduce DefaultProvenance to track the origin of default declarations (local, imported, or built-in), replacing the original cd_module in ClassDefaults with cd_provenance :: DefaultProvenance. * Rename tcDefaults to tcDefaultDecls, limiting its responsibility to only converting renamed class defaults into ClassDefaults. * Add extendDefaultEnvWithLocalDefaults to merge local defaults into the environment, with proper duplication checks: - Duplicate local defaults for a class trigger an error. - Local defaults override imported or built-in defaults. * Update and add related notes: Note [Builtin class defaults], Note [DefaultProvenance]. * Add regression tests: T25912, T25914, T25934. Thanks sam and simon for the help on this patch. Co-authored-by: sheaf <sam.derbyshire(a)gmail.com> - - - - - 386f1854 by Teo Camarasu at 2025-04-17T04:31:55-04:00 template-haskell: Remove `addrToByteArrayName` and `addrToByteArray` These were part of the implementation of the `Lift ByteArray` instance and were errornously exported because this module lacked an explicit export list. They have no usages on Hackage. Resolves #24782 - - - - - aca81c37 by Serge S. Gulin at 2025-04-18T13:10:12+03:00 Support for ARM64 Windows (LLVM-enabled) (fixes #24603) submodule Co-authored-by: Cheng Shao <terrorjack(a)type.dance> Co-authored-by: Dmitrii Egorov <egorov.d.i(a)icloud.com> Co-authored-by: Andrei Borzenkov <root(a)sandwitch.dev> - - - - - 108 changed files: - .gitlab-ci.yml - .gitlab/ci.sh - .gitlab/generate-ci/gen_ci.hs - .gitlab/hello.hs - .gitlab/jobs.yaml - compiler/CodeGen.Platform.h - compiler/GHC/CmmToAsm/AArch64/CodeGen.hs - compiler/GHC/CmmToAsm/AArch64/Instr.hs - compiler/GHC/CmmToAsm/AArch64/Ppr.hs - compiler/GHC/CmmToAsm/Reg/Linear/AArch64.hs - compiler/GHC/Driver/Downsweep.hs - compiler/GHC/Driver/Env.hs - compiler/GHC/Driver/Env/Types.hs - compiler/GHC/Driver/Errors/Ppr.hs - compiler/GHC/Driver/Errors/Types.hs - compiler/GHC/Driver/Main.hs - compiler/GHC/Driver/Make.hs - compiler/GHC/Driver/MakeAction.hs - + compiler/GHC/Driver/Messager.hs - compiler/GHC/Driver/Pipeline.hs-boot - compiler/GHC/Driver/Pipeline/Execute.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Iface/Load.hs - compiler/GHC/Iface/Recomp.hs - compiler/GHC/IfaceToCore.hs - compiler/GHC/Linker/Deps.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Parser/Annotation.hs - compiler/GHC/Parser/PostProcess/Haddock.hs - compiler/GHC/Platform/Regs.hs - compiler/GHC/Runtime/Loader.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/Default.hs - compiler/GHC/Tc/Gen/Export.hs - compiler/GHC/Tc/Module.hs - compiler/GHC/Tc/Utils/Env.hs - compiler/GHC/Types/DefaultEnv.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Unit/External.hs - compiler/GHC/Unit/Finder.hs - − compiler/GHC/Unit/Module/External/Graph.hs - compiler/GHC/Unit/Module/Graph.hs - compiler/GHC/Unit/Module/ModNodeKey.hs - compiler/ghc.cabal.in - hadrian/src/Oracles/Setting.hs - hadrian/src/Rules/BinaryDist.hs - libraries/Cabal - libraries/Win32 - libraries/base/base.cabal.in - libraries/base/changelog.md - − libraries/base/src/GHC/ExecutionStack/Internal.hs - − libraries/base/src/GHC/TypeLits/Internal.hs - − libraries/base/src/GHC/TypeNats/Internal.hs - libraries/base/src/System/CPUTime/Windows.hsc - libraries/base/tests/perf/encodingAllocations.hs - libraries/directory - libraries/haskeline - libraries/process - libraries/template-haskell/Language/Haskell/TH/Syntax.hs - libraries/template-haskell/changelog.md - libraries/unix - llvm-targets - m4/fp_cc_supports_target.m4 - m4/fptools_set_platform_vars.m4 - m4/ghc_tables_next_to_code.m4 - rts/StgCRun.c - rts/linker/PEi386.c - rts/win32/veh_excn.c - + testsuite/tests/default/T25912.hs - + testsuite/tests/default/T25912.stdout - + testsuite/tests/default/T25912_helper.hs - + testsuite/tests/default/T25914.hs - + testsuite/tests/default/T25934.hs - testsuite/tests/default/all.T - testsuite/tests/default/default-fail03.stderr - + testsuite/tests/dependent/should_compile/T12088f.hs - + testsuite/tests/dependent/should_compile/T12088g.hs - + testsuite/tests/dependent/should_compile/T12088i.hs - + testsuite/tests/dependent/should_compile/T12088j.hs - + testsuite/tests/dependent/should_compile/T12088mm1.hs - + testsuite/tests/dependent/should_compile/T12088mm1_helper.hs - + testsuite/tests/dependent/should_compile/T12088mm2.hs - + testsuite/tests/dependent/should_compile/T12088mm2_helper.hs - + testsuite/tests/dependent/should_compile/T12088mm3.hs - + testsuite/tests/dependent/should_compile/T12088mm3_helper.hs - + testsuite/tests/dependent/should_compile/T13790.hs - testsuite/tests/dependent/should_compile/all.T - + testsuite/tests/ghc-api/fixed-nodes/InterfaceModuleGraph.hs - + testsuite/tests/ghc-api/fixed-nodes/InterfaceModuleGraph.stdout - testsuite/tests/ghc-api/fixed-nodes/all.T - testsuite/tests/haddock/should_compile_flag_haddock/T17544_kw.hs - testsuite/tests/haddock/should_compile_flag_haddock/T17544_kw.stderr - testsuite/tests/interface-stability/base-exports.stdout - testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs - testsuite/tests/interface-stability/base-exports.stdout-mingw32 - testsuite/tests/interface-stability/base-exports.stdout-ws-32 - testsuite/tests/interface-stability/template-haskell-exports.stdout - testsuite/tests/linters/notes.stdout - testsuite/tests/module/mod58.stderr - testsuite/tests/plugins/defaulting-plugin/DefaultLifted.hs - + testsuite/tests/vdq-rta/should_fail/T23738_fail_pun.hs - + testsuite/tests/vdq-rta/should_fail/T23738_fail_pun.stderr - testsuite/tests/vdq-rta/should_fail/all.T - utils/ghc-toolchain/exe/Main.hs - utils/hsc2hs - utils/llvm-targets/gen-data-layout.sh The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/3e4129c22be4ba48c7312612c4719f… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/3e4129c22be4ba48c7312612c4719f… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T25888] Test the Interaction of -XExtendedDefaultRules and -XNamedDefaults
by Patrick (＠soulomoon) 18 Apr '25

18 Apr '25

Patrick pushed to branch wip/T25888 at Glasgow Haskell Compiler / GHC Commits: b24033cc by Patrick at 2025-04-18T14:47:51+08:00 Test the Interaction of -XExtendedDefaultRules and -XNamedDefaults Add Testcases T25888v1-2 Fix #25888 - - - - - 5 changed files: - + testsuite/tests/default/T25888v1.hs - + testsuite/tests/default/T25888v1.stdout - + testsuite/tests/default/T25888v2.hs - + testsuite/tests/default/T25888v2.stdout - testsuite/tests/default/all.T Changes: ===================================== testsuite/tests/default/T25888v1.hs ===================================== @@ -0,0 +1,52 @@ +{-# LANGUAGE ExtendedDefaultRules #-} +{-# LANGUAGE NamedDefaults #-} +{-# LANGUAGE RequiredTypeArguments #-} + +module Main where +import Data.Foldable (Foldable(..)) +import Data.Functor.Identity (Identity(..)) + +default Foldable (Maybe) +default Num (Double) +default Show () +-- This is ensured we cleanup defaults for Show, +-- we do not want Show to effect the defaulting of `Num, Foldable`. +-- since we are using Show to print out the result. + +class (Foldable t) => Build t where + polyFold :: forall a -> t a + +instance Build Maybe where + polyFold x = Nothing + +instance Build [] where + polyFold x = [] + + +-- This test demonstrates the functionality of ExtendedDefaultRules and NamedDefaults. +-- +-- By default, ExtendedDefaultRules implicitly provides: +-- default Foldable ([]) +-- default Num (Integer, Double) +-- +-- However, we override these with our explicit declarations: +-- default Foldable (Maybe) +-- default Num (Double) +-- +-- This test verifies that our overrides work correctly: +-- 1. For an unresolved type variable 't' with a 'Foldable t' constraint, +-- 't' defaults to 'Maybe' (not '[]') +-- 2. For an unresolved type variable 'a' with a 'Num a' constraint, +-- 'a' defaults to 'Double' (not 'Integer') +-- +-- Expected outcomes: +-- * 'polyFold Int' evaluates to 'Nothing' (not '[]') +-- * '1' is a 'Double' (1.0) (not an 'Integer') +-- +-- See also T25888v2.hs for a companion test without overriding the defaults + +main :: IO () +main = do + print $ polyFold Int + print $ 1 + ===================================== testsuite/tests/default/T25888v1.stdout ===================================== @@ -0,0 +1,2 @@ +Nothing +1.0 ===================================== testsuite/tests/default/T25888v2.hs ===================================== @@ -0,0 +1,40 @@ +{-# LANGUAGE ExtendedDefaultRules #-} +{-# LANGUAGE NamedDefaults #-} +{-# LANGUAGE RequiredTypeArguments #-} + +module Main where +import Data.Foldable (Foldable(..)) +import Data.Functor.Identity (Identity(..)) + +default Show () +-- This is ensured we cleanup defaults for Show, +-- we do not want Show to effect the defaulting of `Num, Foldable`. +-- since we are using Show to print out the result. + +class (Foldable t) => Build t where + polyFold :: forall a -> t a + +instance Build Maybe where + polyFold x = Nothing + +instance Build [] where + polyFold x = [] + +-- With ExtendedDefaultRules enabled, we implicitly have the following defaults: +-- default Foldable ([]), Num (Integer, Double) +-- These defaults are not overridden in this module. + +-- According to the defaulting rules: +-- 1. For an unresolved type variable 't' with constraint 'Foldable t', 't' defaults to [] +-- 2. For an unresolved type variable 'a' with constraint 'Num a', 'a' defaults to Integer + +-- Therefore: +-- * polyFold Int should evaluate to [] (empty list) +-- * The literal 1 should be of type Integer + +-- See also T25888v1.hs for the same test with overridden defaults +main :: IO () +main = do + print $ polyFold Int + print $ 1 + ===================================== testsuite/tests/default/T25888v2.stdout ===================================== @@ -0,0 +1,2 @@ +[] +1 ===================================== testsuite/tests/default/all.T ===================================== @@ -42,3 +42,5 @@ test('T25882', normal, compile, ['']) test('T25912', [extra_files(['T25912_helper.hs'])], multimod_compile_and_run, ['T25912', '']) test('T25914', normal, compile, ['']) test('T25934', normal, compile, ['']) +test('T25888v1', normal, compile_and_run, ['']) +test('T25888v2', normal, compile_and_run, ['']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b24033cc8613f98c153e7928db43870… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b24033cc8613f98c153e7928db43870… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T25888] Test the Interaction of -XExtendedDefaultRules and -XNamedDefaults
by Patrick (＠soulomoon) 18 Apr '25

18 Apr '25

Patrick pushed to branch wip/T25888 at Glasgow Haskell Compiler / GHC Commits: f8db9375 by Patrick at 2025-04-18T14:46:27+08:00 Test the Interaction of -XExtendedDefaultRules and -XNamedDefaults Add Testcases T25888v1-2 Add comment in tcGetDefaultTys pointing to the Note [Typechecking default declarations] Fix duplication error that happens between different h2010_dflt_clss Fix #25888 - - - - - 6 changed files: - compiler/GHC/Tc/Utils/Env.hs - + testsuite/tests/default/T25888v1.hs - + testsuite/tests/default/T25888v1.stdout - + testsuite/tests/default/T25888v2.hs - + testsuite/tests/default/T25888v2.stdout - testsuite/tests/default/all.T Changes: ===================================== compiler/GHC/Tc/Utils/Env.hs ===================================== @@ -1042,7 +1042,7 @@ tcGetDefaultTys ; numClass <- tcLookupClass numClassName ; pure $ unitDefaultEnv $ builtinDefaults numClass [integer_ty, doubleTy] } - -- The Num class is already user-defaulted, no need to construct the builtin default + -- The Num class is already user-defaulted, no need to construct the builtin default, _ -> pure emptyDefaultEnv -- Supply the built-in defaults, but make the user-supplied defaults -- override them. ===================================== testsuite/tests/default/T25888v1.hs ===================================== @@ -0,0 +1,52 @@ +{-# LANGUAGE ExtendedDefaultRules #-} +{-# LANGUAGE NamedDefaults #-} +{-# LANGUAGE RequiredTypeArguments #-} + +module Main where +import Data.Foldable (Foldable(..)) +import Data.Functor.Identity (Identity(..)) + +default Foldable (Maybe) +default Num (Double) +default Show () +-- This is ensured we cleanup defaults for Show, +-- we do not want Show to effect the defaulting of `Num, Foldable`. +-- since we are using Show to print out the result. + +class (Foldable t) => Build t where + polyFold :: forall a -> t a + +instance Build Maybe where + polyFold x = Nothing + +instance Build [] where + polyFold x = [] + + +-- This test demonstrates the functionality of ExtendedDefaultRules and NamedDefaults. +-- +-- By default, ExtendedDefaultRules implicitly provides: +-- default Foldable ([]) +-- default Num (Integer, Double) +-- +-- However, we override these with our explicit declarations: +-- default Foldable (Maybe) +-- default Num (Double) +-- +-- This test verifies that our overrides work correctly: +-- 1. For an unresolved type variable 't' with a 'Foldable t' constraint, +-- 't' defaults to 'Maybe' (not '[]') +-- 2. For an unresolved type variable 'a' with a 'Num a' constraint, +-- 'a' defaults to 'Double' (not 'Integer') +-- +-- Expected outcomes: +-- * 'polyFold Int' evaluates to 'Nothing' (not '[]') +-- * '1' is a 'Double' (1.0) (not an 'Integer') +-- +-- See also T25888v2.hs for a companion test without overriding the defaults + +main :: IO () +main = do + print $ polyFold Int + print $ 1 + ===================================== testsuite/tests/default/T25888v1.stdout ===================================== @@ -0,0 +1,2 @@ +Nothing +1.0 ===================================== testsuite/tests/default/T25888v2.hs ===================================== @@ -0,0 +1,40 @@ +{-# LANGUAGE ExtendedDefaultRules #-} +{-# LANGUAGE NamedDefaults #-} +{-# LANGUAGE RequiredTypeArguments #-} + +module Main where +import Data.Foldable (Foldable(..)) +import Data.Functor.Identity (Identity(..)) + +default Show () +-- This is ensured we cleanup defaults for Show, +-- we do not want Show to effect the defaulting of `Num, Foldable`. +-- since we are using Show to print out the result. + +class (Foldable t) => Build t where + polyFold :: forall a -> t a + +instance Build Maybe where + polyFold x = Nothing + +instance Build [] where + polyFold x = [] + +-- With ExtendedDefaultRules enabled, we implicitly have the following defaults: +-- default Foldable ([]), Num (Integer, Double) +-- These defaults are not overridden in this module. + +-- According to the defaulting rules: +-- 1. For an unresolved type variable 't' with constraint 'Foldable t', 't' defaults to [] +-- 2. For an unresolved type variable 'a' with constraint 'Num a', 'a' defaults to Integer + +-- Therefore: +-- * polyFold Int should evaluate to [] (empty list) +-- * The literal 1 should be of type Integer + +-- See also T25888v1.hs for the same test with overridden defaults +main :: IO () +main = do + print $ polyFold Int + print $ 1 + ===================================== testsuite/tests/default/T25888v2.stdout ===================================== @@ -0,0 +1,2 @@ +[] +1 ===================================== testsuite/tests/default/all.T ===================================== @@ -42,3 +42,5 @@ test('T25882', normal, compile, ['']) test('T25912', [extra_files(['T25912_helper.hs'])], multimod_compile_and_run, ['T25912', '']) test('T25914', normal, compile, ['']) test('T25934', normal, compile, ['']) +test('T25888v1', normal, compile_and_run, ['']) +test('T25888v2', normal, compile_and_run, ['']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f8db9375e3e5860837ee795f569efad… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f8db9375e3e5860837ee795f569efad… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T25888] 40 commits: Parametrize default logger action with Handles
by Patrick (＠soulomoon) 18 Apr '25

18 Apr '25

Patrick pushed to branch wip/T25888 at Glasgow Haskell Compiler / GHC Commits: f827c4c6 by Rodrigo Mesquita at 2025-04-07T11:22:10-04:00 Parametrize default logger action with Handles Introduce `defaultLogActionWithHandles` to allow GHC applications to use GHC's formatting but using custom handles. `defaultLogAction` is then trivially reimplemented as ``` defaultLogActionWithHandles stdout stderr ``` - - - - - 5dade5fd by sheaf at 2025-04-07T11:23:02-04:00 Finer-grained recompilation checking for exports This commit refines the recompilation checking logic, to avoid recompiling modules with an explicit import list when the modules they import start exporting new items. More specifically, when: 1. module N imports module M, 2. M is changed, but in a way that: a. preserves the exports that N imports b. does not introduce anything that forces recompilation downstream, such as orphan instances then we no longer require recompilation of N. Note that there is more to (2a) as initially meets the eye: - if N includes a whole module or "import hiding" import of M, then we require that the export list of M does not change, - if N only includes explicit imports, we check that the imported items don't change, e.g. - if we have @import M(T(K, f), g)@, we must check that N continues to export all these identifiers, with the same Avail structure (i.e. we should error if N stops bundling K or f with T) - if we have @import M(T(..))@, we must check that the children of T have not changed See Note [When to recompile when export lists change?] in GHC.Iface.Recomp. This is all tested in the new tests RecompExports{1,2,3,4,5} Fixes #25881 - - - - - f32d6c2b by Andreas Klebinger at 2025-04-07T22:01:25-04:00 NCG: AArch64 - Add -finter-module-far-jumps. When enabled the arm backend will assume jumps to targets outside of the current module are further than 128MB away. This will allow for code to work if: * The current module results in less than 128MB of code. * The whole program is loaded within a 4GB memory region. We have seen a few reports of broken linkers (#24648) where this flag might allow a program to compile/run successfully at a very small performance cost. ------------------------- Metric Increase: T783 ------------------------- - - - - - 553c280b by Andreas Klebinger at 2025-04-07T22:02:11-04:00 Revert "rts: fix small argument passing on big-endian arch (fix #23387)" Based on analysis documented in #25791 this doesn't fully fix the big while introducing new bugs on little endian architectures. A more complete fix will have to be implemented to fix #23387 This reverts commit 4f02d3c1a7b707e609bb3aea1dc6324fa19a5c39. - - - - - b0dc6599 by Andreas Klebinger at 2025-04-07T22:02:11-04:00 Interpreter: Fixes to handling of subword value reads/writes. Load subword values as full words from the stack truncating/expanding as neccesary when dealing with subwords. This way byte order is implicitly correct. This commit also fixes the order in which we are pushing literals onto the stack on big endian archs. Last but not least we enable a test for ghci which actually tests these subword operations. - - - - - ed38c09b by Cheng Shao at 2025-04-07T22:02:53-04:00 testsuite: don't test WasmControlFlow stdout This patch solves a potential test flakiness in `WasmControlFlow` by removing `WasmControlFlow.stdout` which is not so portable/stable as it seems. See added `Note [WasmControlFlow]` for more detailed explanation. - - - - - f807c590 by Rodrigo Mesquita at 2025-04-08T17:41:51-04:00 debugger: Add docs to obtainTermFromId - - - - - 5dba052d by Rodrigo Mesquita at 2025-04-08T17:41:51-04:00 Move logic to find and set Breakpoint to GHC Breakpoints are uniquely identified by a module and an index unique within that module. `ModBreaks` of a Module contains arrays mapping from this unique breakpoint index to information about each breakpoint. For instance, `modBreaks_locs` stores the `SrcSpan` for each breakpoint. To find a breakpoint using the line number you need to go through all breakpoints in the array for a given module and look at the line and column stored in the `SrcSpan`s. Similarly for columns and finding breakpoints by name. This logic previously lived within the `GHCi` application sources, however, it is common to any GHC applications wanting to set breakpoints, like the upcoming `ghc-debugger`. This commit moves this logic for finding and setting breakpoints to the GHC library so it can be used by both `ghci` and `ghc-debugger`. - - - - - bc0b9f73 by Rodrigo Mesquita at 2025-04-08T17:41:51-04:00 Refactor and move logic for identifier breakpoints Breakpoints can be set on functions using syntax of the form `[Module.]function`. The parsing, resolution (e.g. inferring implicit module), and validation of this syntax for referring to functions was tightly coupled with its GHCi use. This commit extracts the general purpose bits of resolving this syntax into `GHC.Runtime.Debugger.Breakpoints` so it can be further used by other GHC applications and to improve the code structure of GHCi. Moreover, a few utilities that do splitting and joining of identifiers as strings were moved to `GHC.Runtime.Eval.Utils`, which also can be used in the future to clean up `GHC.Runtime.Eval` a bit. - - - - - 4f728d21 by Rodrigo Mesquita at 2025-04-08T17:41:51-04:00 debugger: derive Ord for BreakpointIds - - - - - 5528771c by Rodrigo Mesquita at 2025-04-08T17:41:51-04:00 debugger: Move context utils from GHCi to GHC Moves `enclosingTickSpan`, `getCurrentBreakSpan`, and `getCurrentBreakModule`, general utilities on the internal debugger state, into the GHC library. - - - - - 4871f543 by sheaf at 2025-04-08T17:42:43-04:00 Implicit quantification in type synonyms: add test This adds a test for ticket #24090, which involves implicit quantification in type synonyms. The underlying issue was fixed in 0d4ee209dfe53e5074d786487f531dabc36d561c. - - - - - 48917d3c by sheaf at 2025-04-08T17:42:44-04:00 Turn on implicit-rhs-quantification by default This flag was added to GHC 9.8, and will be removed in a future GHC release. In preparation, this commit adds it to the default warning flags. - - - - - 629be068 by Rodrigo Mesquita at 2025-04-08T17:43:26-04:00 debugger: Add breakpoints to every Stmt While single-stepping through a Haskell program we stop at every breakpoint. However, we don't introduce breakpoints at every single expression (e.g. single variables) because they would be too many and uninteresting. That said, in a do-block, it is expected that stepping over would break at every line, even if it isn't particularly interesting (e.g. a single arg like getArgs). Moreover, let-statements in do-blocks, despite only being evaluated once needed, lead to surprising jumps while stepping through because some have outermost (outside the let) breakpoints while others don't. This commit makes every statement in a do-block have a breakpoint. This leads to predictable stepping through in a do-block. Duplicate breakpoints in the same location are avoided using the existing blacklist mechanism, which was missing a check in one relevant place. Fixes #25932 - - - - - 99a3affd by Matthew Pickering at 2025-04-08T17:44:08-04:00 driver: refactor: Split downsweep and MakeAction into separate modules. This will facilitate using the downsweep functions in other parts of the compiler than just --make mode. Also, the GHC.Driver.Make module was huge. Now it's still huge but slightly smaller! - - - - - ecfec4df by sheaf at 2025-04-09T14:13:12-04:00 Store user-written qualification in the GhcRn AST This commit ensures we store the original user-written module qualification in the renamed AST. This allows us to take into account the user-written qualification in error messages. Fixes #25877 - - - - - 97c884e2 by sheaf at 2025-04-09T14:13:12-04:00 TcRnIllegalTermLevelUse: simpler error when possible This commit makes GHC emit a simple error message in the case of an illegal term-level use of a data constructor: we will try to report an out-of-scope error instead of a "Illegal term level use" error, as the latter might be a bit overwhelming for newcomers. We do this when we have a data constructor import suggestion to provide to the user. For example: module M where { data A = A } module N where import M(A) x = Bool -- Illegal term-level use of Bool y = A -- Data constructor not in scope: A. -- Perhaps add 'A' to the import list of 'M'. This commit also revamps the "similar names" suggestion mechanism, and in particular its treatment of name spaces. Now, which name spaces we suggest is based solely on what we are looking for, and no longer on the NameSpace of the Name we have. This is because, for illegal term-level use errors, it doesn't make much sense to change the suggestions based on the fact that we resolved to e.g. a type constructor/class; what matters is what we were expecting to see in this position. See GHC.Rename.Unbound.{suggestionIsRelevant,relevantNameSpace} as well as the new constructors to GHC.Tc.Errors.Types.WhatLooking. Fixes #23982 - - - - - bff645ab by Rodrigo Mesquita at 2025-04-09T14:13:57-04:00 driver: Split Session functions out of Main This commit moves out functions that help in creating and validating a GHC multi session from Main into the ghc library where they can be used by other GHC applications. Moreover, `Mode` processing and `checkOptions` linting were moved to separate modules within the ghc-bin executable package. In particular: - Move `Mode` types and functions (referring to the mode GHC is running on) to `ghc-bin:GHC.Driver.Session.Mode` - Move `checkOptions` and aux functions, which validates GHC DynFlags based on the mode, to `ghc-bin:GHC.Driver.Session.Lint` - Moves `initMulti`, `initMake`, and aux functions, which initializes a make/multi-unit session, into `ghc:GHC.Driver.Session.Units`. - - - - - 501b015e by Rodrigo Mesquita at 2025-04-09T14:13:57-04:00 docs: Improve haddock of ExecComplete - - - - - dea98988 by Andreas Klebinger at 2025-04-09T19:23:57-04:00 Avoid oversaturing constructor workers. Constructor applications always need to take the exact number of arguments. If we can't ensure that instead apply the constructor worker like a regular function. Fixes #23865 - - - - - f1acdd2c by sheaf at 2025-04-09T19:25:41-04:00 NamedDefaults: require the class to be standard We now only default type variables if they only appear in constraints of the form `C v`, where `C` is either a standard class or a class with an in-scope default declaration. This rectifies an oversight in the original implementation of the NamedDefault extensions that was remarked in #25775; that implementation allowed type variables to appear in unary constraints which had arbitrary classes at the head. See the rewritten Note [How type-class constraints are defaulted] for details of the implementation. Fixes #25775 Fixes #25778 - - - - - 5712e0d6 by Vladislav Zavialov at 2025-04-10T05:17:38+00:00 Retry type/class declarations and instances (#12088) Retry type/class declarations and instances to account for non-lexical dependencies arising from type/data family instances. This patch improves the kind checker's ability to use type instances in kind checking of other declarations in the same module. * Key change: tcTyAndClassDecls now does multiple passes over the TyClGroups, as long as it is able to make progress. See the new Note [Retrying TyClGroups] in GHC.Tc.TyCl * Supporting change: FVs of a TyClGroup are now recorded in its extension field, namely XCTyClGroup. See the new Note [Prepare TyClGroup FVs] in GHC.Rename.Module * Instances are no longer inserted at the earliest positions where their FVs are bound. This is a simplification. See the new Note [Put instances at the end] in GHC.Rename.Module * Automatic unpacking is now more predictable, but fewer fields get unpacked by default. Use explicit {-# UNPACK #-} pragmas instead. See the new Note [Flaky -funbox-strict-fields with type/data families] For the wide range of newly accepted programs, consult the added test cases. Fixed tickets: #12088, #12239, #14668, #15561, #16410, #16448, #16693, #19611, #20875, #21172, #22257, #25238, #25834 Metric Decrease: T8095 - - - - - bc73a78d by sheaf at 2025-04-10T15:07:24-04:00 checkFamApp: don't be so eager to cycle break As remarked in #25933, a pure refactoring of checkTyEqRhs in ab77fc8c7adebd610aa0bd99d653f9a6cc78a374 inadvertently changed behaviour, as it caused GHC to introduce cycle-breaker variables in some unnecessary circumstances. This commit refactors 'GHC.Tc.Utils.Unify.checkFamApp' in a way that should restore the old behaviour, so that, when possible, we first recur into the arguments and only introduce a cycle breaker if this recursion fails (e.g. due to an occurs check failure). Fixes #25933 - - - - - 3acd8182 by Andreas Klebinger at 2025-04-10T22:32:12-04:00 Expand docs for RTS flag `-M`. The behaviour of how/when exceptions are raised was not really covered in the docs. - - - - - 026c1a39 by Adam Sandberg Ericsson at 2025-04-10T22:32:56-04:00 add cases for more SchedulerStatus codes in rts_checkSchedStatus - - - - - 5977c6a1 by sheaf at 2025-04-10T22:33:46-04:00 Squash warnings in GHC.Runtime.Heap.Inspect There were incomplete record selector warnings in GHC.Runtime.Heap.Inspect due to the use of the partial 'dataArgs' record selector. This is fixed by passing the fields to the 'extractSubTerms' function directly, rather than passing a value of the parent data type. - - - - - 6a3e38f5 by Andreas Klebinger at 2025-04-11T15:13:53-04:00 hadrian: Make ghcWithInterpreter the universal source of truth about availability of the interpreter We were doing some ad-hoc checks in different places in hadrian to determine whether we supported the interprter or not. Now this check if confined to one function, `ghcWithInterpreter`, and all the places which use this information consult `ghcWithInterpreter` to determine what to do. Fixes #25533. - - - - - 207de6f1 by Matthew Pickering at 2025-04-11T15:14:37-04:00 testsuite: Fix running TH tests with profiled dynamic compiler Previously, I had failed to update the ghc_th_way_flags logic for the profiled dynamic compiler. In addition to this `ghc_dynamic` was incorrectly set for profiled dynamic compiler. I also updated MultiLayerModulesTH_OneShot test to work for any compiler linkage rather than just dynamic. Fixes #25947 ------------------------- Metric Decrease: MultiLayerModulesTH_Make ------------------------- - - - - - 5455f2b9 by Matthew Pickering at 2025-04-12T08:31:36-04:00 driver: Add support for "Fixed" nodes in the ModuleGraph A fixed node in the module graph is one which we presume is already built. It's therefore up to the user to make sure that the interface file and any relevant artifacts are available for a fixed node. Fixed/Compile nodes are represented by the ModuleNodeInfo type, which abstracts the common parts of Fixed/Compile nodes with accessor functions of type `ModuleNodeInfo -> ...`. Fixed nodes can only depend on other fixed nodes. This invariant can be checked by the function `checkModuleGraph` or `mkModuleGraphChecked`. --make mode is modified to work with fixed mode. In order to "compile" a fixed node, the artifacts are just loaded into the HomePackageTable. Currently nothing in the compiler will produce Fixed nodes but this is tested with the FixedNodes GHC API test. In subsequent patches we are going to remove the ExternalModuleGraph and use Fixed nodes for modules in the module graph in oneshot mode. Fixes #25920 - - - - - ad64d5c2 by Cheng Shao at 2025-04-12T08:32:19-04:00 ci: remove manual case of ghc-wasm-meta downstream testing jobs This patch removes the manual case of ghc-wasm-meta downstream testing jobs; now the only way of including them in the pipeline and running them is via the test-wasm label. The reason of the removal is it proves to be problematic for MRs with only the wasm label; the wasm job would succeed, then the pipeline status would be waiting for manual action instead of succeeding. There needs to be separate jobs for the label-triggered and manual-triggered cases, but I don't think it's worth that extra complexity, the label-triggered case is already sufficient. - - - - - b34890c7 by Vladislav Zavialov at 2025-04-13T01:08:21+03:00 Fix EmptyCase panic in tcMatches (#25960) Due to faulty reasoning in Note [Pattern types for EmptyCase], tcMatches was too keen to panic. * Old (incorrect) assumption: pat_tys is a singleton list. This does not hold when \case{} is checked against a function type preceded by invisible forall. See the new T25960 test case. * New (hopefully correct) assumption: vis_pat_tys is a singleton list. This should follow from: checkArgCounts :: MatchGroup GhcRn ... -> TcM VisArity checkArgCounts (MG { mg_alts = L _ [] }) = return 1 ... - - - - - 84806ebc by Vladislav Zavialov at 2025-04-13T11:40:08-04:00 Remove unused type: TokenLocation - - - - - 05eb50df by Vladislav Zavialov at 2025-04-13T19:16:38-04:00 Register EpToken in Parser.PostProcess.Haddock (#22558) This change allows us to reject more badly placed Haddock comments. Examples: module -- | Bad comment for the module T17544_kw where data Foo -- | Bad comment for MkFoo where MkFoo :: Foo newtype Bar -- | Bad comment for MkBar where MkBar :: () -> Bar class Cls a -- | Bad comment for clsmethod where clsmethod :: a - - - - - 01944e5e by Vladislav Zavialov at 2025-04-13T19:17:21-04:00 Reject puns in T2T (#24153) This patch implements pun detection in T2T. Consider: x = 42 f, g :: forall a -> ... f (type x) = g x In accordance with the specification, the `g x` function call is renamed as a term, so `x` refers to the top-level binding `x = 42`, not to the type variable binding `type x` as one might expect. This is somewhat counterintuitive because `g` expects a type argument. Forbidding puns in T2T allows us to produce a helpful error message: Test.hs:5:16: error: [GHC-09591] Illegal punned variable occurrence in a required type argument. The name ‘x’ could refer to: ‘x’ defined at Test.hs:3:1 ‘x’ bound at Test.hs:5:9 This commit is a follow up to 0dfb1fa799af254c8a1e1045fc3996af2d57a613 where checking for puns was left as future work. - - - - - cc580552 by Vladislav Zavialov at 2025-04-13T19:18:02-04:00 Additional test cases for #12088, #13790 Extract more test cases from ticket discussions, including multi-module examples. Follow up to 5712e0d646f611dfbfedfd7ef6dff3a18c016edb - - - - - d47bf776 by Matthew Pickering at 2025-04-14T16:44:41+01:00 driver: Use ModuleGraph for oneshot and --make mode This patch uses the `hsc_mod_graph` field for both oneshot and --make mode. Therefore, if part of the compiler requires usage of the module graph, you do so in a uniform way for the two different modes. The `ModuleGraph` describes the relationship between the modules in the home package and units in external packages. The `ModuleGraph` can be queried when information about the transitive closure of a package is needed. For example, the primary use of the ModuleGraph from within the compiler is in the loader, which needs to know the transitive closure of a module so it can load all the relevant objects for evaluation. In --make mode, downsweep computes the ModuleGraph before any compilation starts. In oneshot mode, a thunk is created at the start of compilation, which when forced will compute the module graph beneath the current module. The thunk is only forced at the moment when the user uses Template Haskell. Finally, there are some situations where we need to discover what dependencies to load but haven't loaded a module graph at all. In this case, there is a fallback which computes the transitive closure on the fly and doesn't cache the result. Presumably if you are going to call getLinkDeps a lot, you would compute the right ModuleGraph before you started. Importantly, this removes the ExternalModuleGraph abstraction. This was quite awkward to work with since it stored information about the home package inside the EPS. This patch will also be very useful when implementing explicit level imports, which requires more significant use of the module graph in order to determine which level instances are available at. Towards #25795 ------------------------- Metric Decrease: MultiLayerModulesTH_Make MultiLayerModulesTH_OneShot ------------------------- - - - - - 395e0ad1 by sheaf at 2025-04-16T12:33:26-04:00 base: remove .Internal modules (e.g. GHC.TypeLits) This commit removes the following internal modules from base, as per CLC proposal 217: - GHC.TypeNats.Internal - GHC.TypeLits.Internal - GHC.ExecutionStack.Internal Fixes #25007 - - - - - e0f3ff11 by Patrick at 2025-04-17T04:31:12-04:00 Refactor Handling of Multiple Default Declarations Fixes: #25912, #25914, #25934 Previously, GHC discarded all loaded defaults (tcg_default) when local defaults were encountered during typechecking. According to the exportable-named-default proposal (sections 2.4.2 and 2.4.3), local defaults should be merged into tcg_default, retaining any defaults already present while overriding where necessary. Key Changes: * Introduce DefaultProvenance to track the origin of default declarations (local, imported, or built-in), replacing the original cd_module in ClassDefaults with cd_provenance :: DefaultProvenance. * Rename tcDefaults to tcDefaultDecls, limiting its responsibility to only converting renamed class defaults into ClassDefaults. * Add extendDefaultEnvWithLocalDefaults to merge local defaults into the environment, with proper duplication checks: - Duplicate local defaults for a class trigger an error. - Local defaults override imported or built-in defaults. * Update and add related notes: Note [Builtin class defaults], Note [DefaultProvenance]. * Add regression tests: T25912, T25914, T25934. Thanks sam and simon for the help on this patch. Co-authored-by: sheaf <sam.derbyshire(a)gmail.com> - - - - - 386f1854 by Teo Camarasu at 2025-04-17T04:31:55-04:00 template-haskell: Remove `addrToByteArrayName` and `addrToByteArray` These were part of the implementation of the `Lift ByteArray` instance and were errornously exported because this module lacked an explicit export list. They have no usages on Hackage. Resolves #24782 - - - - - c41e910e by Patrick at 2025-04-18T14:44:57+08:00 Test the Interaction of -XExtendedDefaultRules and -XNamedDefaults Add Testcases T25888v1-2 Add comment in tcGetDefaultTys pointing to the Note [Typechecking default declarations] Fix duplication error that happens between different h2010_dflt_clss Fix #25888 - - - - - 342 changed files: - .gitlab-ci.yml - compiler/GHC.hs - compiler/GHC/CmmToAsm/AArch64/CodeGen.hs - compiler/GHC/CmmToAsm/Config.hs - compiler/GHC/CoreToStg.hs - compiler/GHC/Driver/Backpack.hs - compiler/GHC/Driver/Config/CmmToAsm.hs - + compiler/GHC/Driver/Downsweep.hs - compiler/GHC/Driver/DynFlags.hs - compiler/GHC/Driver/Env.hs - compiler/GHC/Driver/Env/Types.hs - compiler/GHC/Driver/Errors/Ppr.hs - compiler/GHC/Driver/Errors/Types.hs - compiler/GHC/Driver/Flags.hs - compiler/GHC/Driver/Main.hs - compiler/GHC/Driver/Make.hs - + compiler/GHC/Driver/MakeAction.hs - compiler/GHC/Driver/MakeFile.hs - + compiler/GHC/Driver/Messager.hs - compiler/GHC/Driver/Pipeline.hs-boot - compiler/GHC/Driver/Pipeline/Execute.hs - compiler/GHC/Driver/Session.hs - + compiler/GHC/Driver/Session/Units.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Extension.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Pat.hs - compiler/GHC/Hs/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/HsToCore/Ticks.hs - compiler/GHC/HsToCore/Usage.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Load.hs - compiler/GHC/Iface/Make.hs - compiler/GHC/Iface/Recomp.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/IfaceToCore.hs - compiler/GHC/Linker/Deps.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Parser/Annotation.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Parser/PostProcess/Haddock.hs - compiler/GHC/Rename/Bind.hs - compiler/GHC/Rename/Env.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Rename/HsType.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Rename/Names.hs - compiler/GHC/Rename/Pat.hs - compiler/GHC/Rename/Splice.hs - compiler/GHC/Rename/Unbound.hs - compiler/GHC/Rename/Utils.hs - + compiler/GHC/Runtime/Debugger/Breakpoints.hs - compiler/GHC/Runtime/Eval.hs - compiler/GHC/Runtime/Eval/Types.hs - + compiler/GHC/Runtime/Eval/Utils.hs - compiler/GHC/Runtime/Heap/Inspect.hs - compiler/GHC/Runtime/Loader.hs - compiler/GHC/StgToByteCode.hs - compiler/GHC/Tc/Errors.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/Default.hs - compiler/GHC/Tc/Gen/Export.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Gen/Match.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/Gen/Splice.hs - compiler/GHC/Tc/Module.hs - compiler/GHC/Tc/Solver/Default.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/TyCl.hs - compiler/GHC/Tc/TyCl/Instance.hs - compiler/GHC/Tc/TyCl/PatSyn.hs - compiler/GHC/Tc/TyCl/Utils.hs - compiler/GHC/Tc/Types.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Utils/Env.hs - compiler/GHC/Tc/Utils/Instantiate.hs - compiler/GHC/Tc/Utils/Monad.hs - compiler/GHC/Tc/Utils/TcMType.hs - compiler/GHC/Tc/Utils/TcType.hs - compiler/GHC/Tc/Utils/Unify.hs - compiler/GHC/Tc/Validity.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/Avail.hs - compiler/GHC/Types/Breakpoint.hs - compiler/GHC/Types/DefaultEnv.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Types/GREInfo.hs - compiler/GHC/Types/Name.hs - compiler/GHC/Types/Name/Occurrence.hs - compiler/GHC/Types/Name/Ppr.hs - compiler/GHC/Types/Name/Reader.hs - compiler/GHC/Types/TyThing/Ppr.hs - compiler/GHC/Unit/External.hs - compiler/GHC/Unit/Finder.hs - compiler/GHC/Unit/Module/Deps.hs - − compiler/GHC/Unit/Module/External/Graph.hs - compiler/GHC/Unit/Module/Graph.hs - compiler/GHC/Unit/Module/ModIface.hs - compiler/GHC/Unit/Module/ModNodeKey.hs - compiler/GHC/Utils/Logger.hs - compiler/GHC/Utils/Outputable.hs - compiler/Language/Haskell/Syntax/Decls.hs - compiler/Language/Haskell/Syntax/Expr.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/Type.hs - compiler/ghc.cabal.in - docs/users_guide/9.14.1-notes.rst - docs/users_guide/runtime_control.rst - docs/users_guide/using-optimisation.rst - docs/users_guide/using-warnings.rst - + ghc/GHC/Driver/Session/Lint.hs - + ghc/GHC/Driver/Session/Mode.hs - ghc/GHCi/UI.hs - ghc/GHCi/UI/Monad.hs - ghc/Main.hs - ghc/ghc-bin.cabal.in - hadrian/src/Oracles/Flag.hs - hadrian/src/Oracles/Setting.hs - hadrian/src/Rules/Generate.hs - hadrian/src/Settings/Builders/Cabal.hs - hadrian/src/Settings/Builders/RunTest.hs - hadrian/src/Settings/Packages.hs - libraries/base/base.cabal.in - libraries/base/changelog.md - − libraries/base/src/GHC/ExecutionStack/Internal.hs - − libraries/base/src/GHC/TypeLits/Internal.hs - − libraries/base/src/GHC/TypeNats/Internal.hs - libraries/ghci/GHCi/ResolvedBCO.hs - libraries/template-haskell/Language/Haskell/TH/Syntax.hs - libraries/template-haskell/changelog.md - rts/Interpreter.c - 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+ testsuite/tests/ghc-api/fixed-nodes/Makefile - + testsuite/tests/ghc-api/fixed-nodes/ModuleGraphInvariants.hs - + testsuite/tests/ghc-api/fixed-nodes/ModuleGraphInvariants.stdout - + testsuite/tests/ghc-api/fixed-nodes/T1.hs - + testsuite/tests/ghc-api/fixed-nodes/T1A.hs - + testsuite/tests/ghc-api/fixed-nodes/T1B.hs - + testsuite/tests/ghc-api/fixed-nodes/T1C.hs - + testsuite/tests/ghc-api/fixed-nodes/all.T - testsuite/tests/ghc-e/should_fail/T9930fail.stderr - + testsuite/tests/ghci.debugger/scripts/T25932.hs - + testsuite/tests/ghci.debugger/scripts/T25932.script - + testsuite/tests/ghci.debugger/scripts/T25932.stdout - testsuite/tests/ghci.debugger/scripts/T8487.script - testsuite/tests/ghci.debugger/scripts/all.T - testsuite/tests/ghci.debugger/scripts/break018.script - testsuite/tests/ghci.debugger/scripts/break018.stdout - testsuite/tests/ghci.debugger/scripts/dynbrk004.stdout - testsuite/tests/ghci.debugger/scripts/dynbrk007.script - testsuite/tests/ghci.debugger/scripts/dynbrk007.stdout - 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testsuite/tests/typecheck/should_fail/T12729.stderr - testsuite/tests/typecheck/should_fail/T12921.stderr - testsuite/tests/typecheck/should_fail/T19978.stderr - + testsuite/tests/typecheck/should_fail/T24090a.hs - + testsuite/tests/typecheck/should_fail/T24090a.stderr - + testsuite/tests/typecheck/should_fail/T24090b.hs - testsuite/tests/wcompat-warnings/WCompatWarningsOn.stderr → testsuite/tests/typecheck/should_fail/T24090b.stderr - + testsuite/tests/typecheck/should_fail/T25004k.hs - + testsuite/tests/typecheck/should_fail/T25004k.stderr - testsuite/tests/typecheck/should_fail/T6018fail.stderr - testsuite/tests/typecheck/should_fail/all.T - + testsuite/tests/vdq-rta/should_fail/T23738_fail_pun.hs - + testsuite/tests/vdq-rta/should_fail/T23738_fail_pun.stderr - testsuite/tests/vdq-rta/should_fail/all.T - testsuite/tests/warnings/should_compile/WarnNoncanonical.stderr - testsuite/tests/wasm/should_run/control-flow/README.md - − testsuite/tests/wasm/should_run/control-flow/WasmControlFlow.stdout - testsuite/tests/wasm/should_run/control-flow/all.T - testsuite/tests/wcompat-warnings/Template.hs - utils/haddock/haddock-api/src/Haddock/Backends/Hoogle.hs - utils/haddock/haddock-api/src/Haddock/Convert.hs - utils/haddock/haddock-api/src/Haddock/GhcUtils.hs - utils/haddock/haddock-api/src/Haddock/Interface.hs - utils/haddock/haddock-api/src/Haddock/Interface/Create.hs - utils/haddock/haddock-api/src/Haddock/Interface/Rename.hs - utils/haddock/haddock-api/src/Haddock/Interface/RenameType.hs - utils/haddock/haddock-api/src/Haddock/Types.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/173d25cda2ea2fc95468cb19927a3c… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/173d25cda2ea2fc95468cb19927a3c… You're receiving this email because of your account on gitlab.haskell.org.

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