Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: 53682431 by Simon Jakobi at 2026-08-14T11:46:25-04:00 testsuite: Expect length001 failure in nonmoving_thr_sanity length001 relies on an optimization rule to avoid excessive stack use. The nonmoving_thr_sanity way does not enable optimization, so classify its stack overflow as an expected failure, as is already done for the other unoptimized nonmoving ways. Assisted-by: gpt-5.6-sol via Codex CLI - - - - - c08a77ff by Simon Jakobi at 2026-08-14T11:46:25-04:00 testsuite: Omit T22859 in nonmoving threaded ways T22859 checks allocation-limit handlers with output that depends on precise allocation behaviour. The nonmoving threaded ways change where these limits are reached, just as the already-omitted LLVM ways do. Omit these ways instead of treating their incidental output differences as test failures. Assisted-by: gpt-5.6-sol via Codex CLI - - - - - 8c1a9eab by Simon Jakobi at 2026-08-14T11:46:25-04:00 rts/js: Implement eq_thread, and test Eq/Ord ThreadId (#16761) Since d1f3c63701, Eq ThreadId is implemented via the RTS function eq_thread, but the JS RTS never provided it, so comparing ThreadIds for equality on the JS backend crashed with ReferenceError: h$eq_thread is not defined Like the C implementation, h$eq_thread uses pointer equality: The JS RTS has exactly one thread object per thread. Since previously no test exercised eq_thread directly, this commit adds a test covering equality, its stability across GC, and agreement with Ord. Assisted-by: Claude Fable 5 - - - - - 1a2b95ef by Simon Jakobi at 2026-08-14T11:46:25-04:00 testsuite: Make listThreads1 insensitive to the RTS's own threads listThreads1 expected `listThreads` to return exactly [ThreadId 1]. That holds only under a non-threaded RTS. Under a threaded RTS however there are more threads present, so we change the test to simply check that `myThreadId` is present in the list. Assisted-by: Claude Opus 5 - - - - - d22fd7ec by Vladislav Zavialov at 2026-08-14T11:46:27-04:00 Fix tcLookupId panic with RequiredTypeArguments and PatternSynonyms (#27586) The arguments declared on the left-hand side of a pattern synonym are looked up as term variables bound by its right-hand side. Prior to this patch, that lookup panicked with RequiredTypeArguments: data T a where MkT :: forall a -> T a pattern P :: Int -> T Int pattern P x = MkT x On the RHS, `x` looks like a term argument, so the renamer binds it in the term namespace. Only during type checking does it turn out to be a type variable, so the lookup on the LHS finds an ATyVar rather than an ATcId. As the lookup was done with tcLookupId, it resulted in a panic. Now the arguments are looked up with tcLookupPatSynArg, which reports an illegal term-level use of `x`, just as an ordinary function definition `f (MkT x) = x` does. Test cases: T27586a T27586b T27586c Assisted-by: Claude Opus 5 - - - - - 17 changed files: - + changelog.d/T27586 - compiler/GHC/Tc/TyCl/PatSyn.hs - libraries/base/tests/all.T - libraries/base/tests/listThreads1.hs - libraries/base/tests/listThreads1.stdout - rts/js/thread.js - + testsuite/tests/concurrent/should_run/T16761.hs - + testsuite/tests/concurrent/should_run/T16761.stdout - testsuite/tests/concurrent/should_run/all.T - testsuite/tests/rts/all.T - + testsuite/tests/vdq-rta/should_fail/T27586a.hs - + testsuite/tests/vdq-rta/should_fail/T27586a.stderr - + testsuite/tests/vdq-rta/should_fail/T27586b.hs - + testsuite/tests/vdq-rta/should_fail/T27586b.stderr - + testsuite/tests/vdq-rta/should_fail/T27586c.hs - + testsuite/tests/vdq-rta/should_fail/T27586c.stderr - testsuite/tests/vdq-rta/should_fail/all.T Changes: ===================================== changelog.d/T27586 ===================================== @@ -0,0 +1,9 @@ +section: compiler +issues: #27586 +mrs: !16440 +synopsis: + Fix a panic on a required type argument in a pattern synonym RHS +description: + An argument of a pattern synonym that is matched against a required type + argument in the right-hand side no longer causes a panic; it is reported as + an illegal term-level use of a type variable. ===================================== compiler/GHC/Tc/TyCl/PatSyn.hs ===================================== @@ -137,7 +137,7 @@ tcInferPatSynDecl (PSB { psb_id = lname@(L _ name), psb_args = details ; (tclvl, wanted, ((lpat', args), pat_ty)) <- pushLevelAndCaptureConstraints $ tcInferPat FRRPatSynArg PatSynCtx lpat $ - mapM tcLookupId arg_names + mapM tcLookupPatSynArg arg_names ; let (ex_tvs, prov_dicts) = tcCollectEx lpat' @@ -472,7 +472,7 @@ tcCheckPatSynDecl psb@PSB{ psb_id = lname@(L _ name), psb_args = details -- location to x's binding site in lpat, namely the 'x' in Just (x,True). -- Else the error message location is wherever tcCheckPat finished, -- namely the right-hand corner of the pattern - do { arg_id <- tcLookupId arg_name + do { arg_id <- tcLookupPatSynArg arg_name ; wrap <- tcSubTypeSigma (OccurrenceOf (idName arg_id)) GenSigCtxt (idType arg_id) @@ -645,6 +645,19 @@ collectPatSynArgInfo details = InfixCon _ name1 name2 -> (map unLoc [name1, name2], True) RecCon _ names -> (map (unLoc . recordPatSynPatVar) names, False) +-- | Look up the 'Id' bound by the pattern for a declared argument of a pattern +-- synonym. With @RequiredTypeArguments@ the argument may turn out to be a type +-- variable, e.g. @pattern P x = MkT x@ where the argument of @MkT@ is a required +-- type argument; then we report an illegal term-level use of @x@ (#27586). +tcLookupPatSynArg :: Name -> TcM Id +tcLookupPatSynArg arg_name + = do { thing <- tcLookup arg_name + ; case thing of + ATcId { tct_id = id } -> return id + AGlobal (AnId id) -> return id + ATyVar {} -> failIllegalTyVar (noUserRdr arg_name) + _ -> pprPanic "tcLookupPatSynArg" (ppr arg_name) } + wrongNumberOfParmsErr :: Name -> Arity -> Arity -> TcM a wrongNumberOfParmsErr name decl_arity missing = failWithTc $ TcRnPatSynArityMismatch name decl_arity missing ===================================== libraries/base/tests/all.T ===================================== @@ -80,7 +80,7 @@ test('length001', # excessive amounts of stack space. So we specifically set a low # stack limit and mark it as failing under a few conditions. [extra_run_opts('+RTS -K8m -RTS'), - expect_fail_for(['normal', 'threaded1', 'llvm', 'nonmoving', 'nonmoving_thr', 'nonmoving_thr_ghc', 'ext-interp']), + expect_fail_for(['normal', 'threaded1', 'llvm', 'nonmoving', 'nonmoving_thr', 'nonmoving_thr_sanity', 'nonmoving_thr_ghc', 'ext-interp']), # JS doesn't support stack limit so the test sometimes passes just fine. Therefore the test is # marked as fragile. when(js_arch(), fragile(22921))], ===================================== libraries/base/tests/listThreads1.hs ===================================== @@ -2,5 +2,10 @@ module Main where import GHC.Conc.Sync +-- Regression test for the JS backend's ListThreadsOp, which used to omit the +-- running thread. Whatever other threads the RTS has is irrelevant here. main :: IO () -main = listThreads >>= print +main = do + tid <- myThreadId + ts <- listThreads + print (tid `elem` ts) ===================================== libraries/base/tests/listThreads1.stdout ===================================== @@ -1 +1 @@ -[ThreadId 1] +True ===================================== rts/js/thread.js ===================================== @@ -110,6 +110,10 @@ function h$rts_getThreadId(t) { // returns a CULLong RETURN_UBX_TUP2((t.tid / Math.pow(2,32))>>>0, (t.tid & 0xFFFFFFFF)>>>0); } +function h$eq_thread(t1,t2) { + return t1 === t2 ? 1 : 0; +} + function h$cmp_thread(t1,t2) { if(t1.tid < t2.tid) return -1; if(t1.tid > t2.tid) return 1; ===================================== testsuite/tests/concurrent/should_run/T16761.hs ===================================== @@ -0,0 +1,25 @@ +-- Test that Eq ThreadId is based on thread identity (eq_thread), +-- not on the numeric thread id, which may wrap around (#16761). +module Main (main) where + +import Control.Concurrent +import System.Mem (performGC) + +main :: IO () +main = do + t0 <- myThreadId + print (t0 == t0) + + mv <- newEmptyMVar + _ <- forkIO (myThreadId >>= putMVar mv) + tChild <- takeMVar mv + print (t0 == tChild) + print (tChild == tChild) + + -- Equality must be stable even after the GC moves the TSOs. + performGC + print (t0 == t0) + + -- Ord must agree with Eq. + print (compare t0 tChild /= EQ) + print (compare t0 t0 == EQ) ===================================== testsuite/tests/concurrent/should_run/T16761.stdout ===================================== @@ -0,0 +1,6 @@ +True +False +True +True +True +True ===================================== testsuite/tests/concurrent/should_run/all.T ===================================== @@ -310,6 +310,8 @@ test('hs_try_putmvar003', # Check forkIO exception determinism under optimization test('T13330', normal, compile_and_run, ['-O']) +test('T16761', normal, compile_and_run, ['']) + test('T26341', normal, compile_and_run, ['']) # Test EINTR for async I/O interrupted by an exception (#26341) ===================================== testsuite/tests/rts/all.T ===================================== @@ -679,7 +679,7 @@ test('T22859', [js_skip, # This test is vulnerable to changes in allocation behaviour, so we disable it in some ways when(arch('wasm32'), skip), - omit_ways(llvm_ways)], + omit_ways(llvm_ways + ['nonmoving_thr', 'nonmoving_thr_sanity'])], compile_and_run, ['-with-rtsopts -A8K']) # These tests need access to the internal RTS headers. ===================================== testsuite/tests/vdq-rta/should_fail/T27586a.hs ===================================== @@ -0,0 +1,9 @@ +{-# LANGUAGE GADTs, RequiredTypeArguments, PatternSynonyms #-} + +module T27586a where + +data T a where + MkT :: forall a -> T a + +pattern P :: Int -> T Int +pattern P x = MkT x ===================================== testsuite/tests/vdq-rta/should_fail/T27586a.stderr ===================================== @@ -0,0 +1,5 @@ +T27586a.hs:9:19: error: [GHC-01928] + • Illegal term-level use of the type variable ‘x’ + • bound at T27586a.hs:9:19 + • In the declaration for pattern synonym ‘P’ + ===================================== testsuite/tests/vdq-rta/should_fail/T27586b.hs ===================================== @@ -0,0 +1,8 @@ +{-# LANGUAGE GADTs, RequiredTypeArguments, PatternSynonyms #-} + +module T27586b where + +data T a where + MkT :: forall a -> T a + +pattern P x = MkT x ===================================== testsuite/tests/vdq-rta/should_fail/T27586b.stderr ===================================== @@ -0,0 +1,5 @@ +T27586b.hs:8:15: error: [GHC-01928] + • Illegal term-level use of the type variable ‘x’ + • bound at T27586b.hs:8:19 + • In the declaration for pattern synonym ‘P’ + ===================================== testsuite/tests/vdq-rta/should_fail/T27586c.hs ===================================== @@ -0,0 +1,9 @@ +{-# LANGUAGE GADTs, RequiredTypeArguments, PatternSynonyms #-} + +module T27586c where + +data T a where + MkT :: forall a -> T a + +pattern P :: Int -> T Int +pattern P x <- MkT x ===================================== testsuite/tests/vdq-rta/should_fail/T27586c.stderr ===================================== @@ -0,0 +1,5 @@ +T27586c.hs:9:20: error: [GHC-01928] + • Illegal term-level use of the type variable ‘x’ + • bound at T27586c.hs:9:20 + • In the declaration for pattern synonym ‘P’ + ===================================== testsuite/tests/vdq-rta/should_fail/all.T ===================================== @@ -35,3 +35,6 @@ test('T25127_fail_arity', normal, compile_fail, ['']) test('T27440e', normal, compile_fail, ['']) test('T27583f', normal, compile_fail, ['']) +test('T27586a', normal, compile_fail, ['']) +test('T27586b', normal, compile_fail, ['']) +test('T27586c', normal, compile_fail, ['']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/418e821bc2c9e4287c6495abd9856a7... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/418e821bc2c9e4287c6495abd9856a7... You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help