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[Git][ghc/ghc][wip/T17833] Seed the simplifier's in-scope set for open expressions
by Sebastian Graf (＠sgraf812) 17 Jun '26

17 Jun '26

Sebastian Graf pushed to branch wip/T17833 at Glasgow Haskell Compiler / GHC Commits: aa05778e by Sebastian Graf at 2026-06-16T23:26:35+02:00 Seed the simplifier's in-scope set for open expressions simplifyExpr simplifies expressions typed at the GHCi prompt and the results of Template Haskell splices. Such an expression may be open: at a GHCi debugger breakpoint its free variables include RuntimeUnk skolems standing for as-yet-unknown types. The simplifier began with an in-scope set holding only the wildcard binder, so when it instantiated the unsafeCoerce# wrapper that GHCi builds around a result, it formed a substitution whose range mentioned a free skolem that was not in scope. That breaks the substitution invariant and, in a compiler built with assertions, trips substTy's sanity check. Seed the initial in-scope set with the free variables of the expression. For a closed expression this adds nothing. See Note [Seed the in-scope set for open expressions]. Fixes #17833 and its duplicate #21118. - - - - - 3 changed files: - + changelog.d/T17833 - compiler/GHC/Core/Opt/Simplify.hs - testsuite/tests/ghci.debugger/scripts/all.T Changes: ===================================== changelog.d/T17833 ===================================== @@ -0,0 +1,11 @@ +section: compiler +synopsis: Fix a Simplifier panic on open expressions (e.g. in the GHCi debugger) +issues: #17833 #21118 +mrs: !16187 +description: { + ``simplifyExpr`` now seeds the Simplifier's in-scope set with the free + variables of the expression being simplified, restoring the invariant that the + in-scope set contains all of an expression's free variables. This fixes a panic + (a failed ``substTy`` assertion) when an open expression reaches the Simplifier, + as can happen for expressions entered in the GHCi debugger. +} ===================================== compiler/GHC/Core/Opt/Simplify.hs ===================================== @@ -14,6 +14,7 @@ import GHC.Core.Rules import GHC.Core.Ppr ( pprCoreBindings, pprCoreExpr ) import GHC.Core.Opt.OccurAnal ( occurAnalysePgm, occurAnalyseExpr ) import GHC.Core.Stats ( coreBindsSize, coreBindsStats, exprSize ) +import GHC.Core.FVs ( exprFreeVars ) import GHC.Core.Utils ( mkTicks, stripTicksTop ) import GHC.Core.Lint ( LintPassResultConfig, dumpPassResult, lintPassResult ) import GHC.Core.Opt.Simplify.Iteration ( simplTopBinds, simplExpr, simplImpRules ) @@ -74,7 +75,10 @@ simplifyExpr logger euc opts expr ; let fam_envs = ( eps_fam_inst_env eps , extendFamInstEnvList emptyFamInstEnv $ se_fam_inst opts ) - simpl_env = mkSimplEnv (se_mode opts) fam_envs + -- See Note [Seed the in-scope set for open expressions] + simpl_env = setInScopeSet base_env + (getInScope base_env `extendInScopeSetSet` exprFreeVars expr) + base_env = mkSimplEnv (se_mode opts) fam_envs top_env_cfg = se_top_env_cfg opts read_eps_rules = eps_rule_base <$> eucEPS euc read_ruleenv = updExternalPackageRules emptyRuleEnv <$> read_eps_rules @@ -94,6 +98,49 @@ simplifyExpr logger euc opts expr ; return expr' } +{- Note [Seed the in-scope set for open expressions] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +An invariant of the Simplifier is that the in-scope set contains all the free +variables of the expression being simplified. Why? So that the Simplifier +never invents a "fresh" binder that accidentally captures one of those free +variables. + +'simplifyExpr' establishes that invariant by initialising the in-scope set with +the free variables of the expression it is given. For a closed expression this +adds nothing. + +But how can 'simplifyExpr' be handed an /open/ expression in the first place? +The whole-module pipeline never does so: 'simplifyPgm' only ever simplifies +closed bindings. The one caller that can is 'hscCompileCoreExpr' (in +GHC.Driver.Main.Passes), which compiles a single Core expression, and is itself +reached from just two places: + + * GHCi, for an expression typed at the prompt, and in particular in the + debugger (see below); + * Template Haskell, when running a splice (see GHC.Tc.Gen.Splice). + +So this is never on the critical path for mainstream compilation. + +Here is how the debugger hands us an open expression (test break006). We are +stopped at a breakpoint in + mymap f (x:xs) = f x : ... +where the debugger knows that 'x :: Int' but not yet the result type of 'f'. So +it invents a RuntimeUnk skolem 'a' and gives 'f :: Int -> a'. The user then +types + let y = f x +GHCi type-checks that and, to hand the result back to the interpreter (see +GHC.Tc.Module.tcGhciStmts), wraps it as + returnIO @[Any] [unsafeCoerce# @LiftedRep @LiftedRep @a @Any y] +in which the skolem 'a' is free. + +When the Simplifier instantiates that 'unsafeCoerce#', it builds a substitution +mapping unsafeCoerce#'s quantified type variables to (LiftedRep, LiftedRep, a, +Any), whose range therefore mentions 'a'. The in-scope set of a substitution +must contain the free variables of its range (see Note [The substitution +invariant] in GHC.Core.TyCo.Subst). Without the seeding above that invariant is +broken, and in a compiler built with assertions substTy's sanity check fails +(#17833, and its duplicate #21118). -} + simplExprGently :: SimplEnv -> CoreExpr -> SimplM CoreExpr -- ^ Simplifies an expression by doing occurrence analysis, then simplification, -- and repeating (twice currently), because one pass alone leaves tons of crud. ===================================== testsuite/tests/ghci.debugger/scripts/all.T ===================================== @@ -52,8 +52,7 @@ test('break002', extra_files(['../Test2.hs']), ghci_script, ['break002.script']) test('break003', extra_files(['../Test3.hs']), ghci_script, ['break003.script']) test('break005', extra_files(['../QSort.hs']), ghci_script, ['break005.script']) test('break006', - [ when(compiler_debugged(), expect_broken(17833)), - extra_files(['../Test3.hs'])], + [extra_files(['../Test3.hs'])], ghci_script, ['break006.script']) test('break007', extra_files(['Break007.hs']), ghci_script, ['break007.script']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/aa05778e10156f3b571ce429e3b3c20… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/aa05778e10156f3b571ce429e3b3c20… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T27383] Desugar a `case` scrutinee only once (#27383, #20251)
by Sebastian Graf (＠sgraf812) 17 Jun '26

17 Jun '26

Sebastian Graf pushed to branch wip/T27383 at Glasgow Haskell Compiler / GHC Commits: 331843b8 by Sebastian Graf at 2026-06-16T23:25:26+02:00 Desugar a `case` scrutinee only once (#27383, #20251) In `dsExpr` for `HsCase` we desugared the scrutinee /twice/: once to build the Core `case` itself, and again inside `matchWrapper`, which re-desugared the source scrutinee (via `addHsScrutTmCs`) purely to record long-distance information for the pattern-match checker. For a single `case` that is merely wasteful. But for nested cases it is catastrophic. Consider case (case (case e of ... ) of ... ) of ... Desugaring the outer scrutinee desugars the middle `case` twice, each of which desugars the inner `case` twice, and so on. The work doubles at every level, so desugaring takes O(2^n) time in the nesting depth. That is the blowup reported in #27383; it is also what makes the machine-generated program in #20251 take an age to compile. The fix is simple. `matchWrapper` is handed the scrutinee anyway, so we give it the Core expression we have /already/ desugared, and record the long-distance term constraint with `addCoreScrutTmCs` instead of re-desugaring from source. This is just what `matchSinglePatVar` already does for single-pattern matches. So: * `matchWrapper` now takes `Maybe [CoreExpr]` rather than `Maybe [LHsExpr GhcTc]`. * The `HsCase` equation of `dsExpr` passes the already-desugared `core_discrim`; the arrow desugarer passes its match variables. * `addHsScrutTmCs` had no other use, so it is gone. Desugaring is now linear in the nesting depth. (The coverage checker still runs `simpleOptExpr` over each scrutinee, which leaves the total at O(n^2); that is ample.) The long-distance information itself is unchanged: the checker sees precisely the Core that backs the generated code. Test: deSugar/should_compile/T27383 - - - - - 8 changed files: - + changelog.d/fix-exponential-case-desugar-27383 - compiler/GHC/HsToCore/Arrows.hs - compiler/GHC/HsToCore/Expr.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Match.hs-boot - compiler/GHC/HsToCore/Pmc.hs - + testsuite/tests/deSugar/should_compile/T27383.hs - testsuite/tests/deSugar/should_compile/all.T Changes: ===================================== changelog.d/fix-exponential-case-desugar-27383 ===================================== @@ -0,0 +1,6 @@ +section: compiler +synopsis: Fix exponential-time desugaring of nested ``case`` expressions. + The scrutinee is no longer desugared a second time when recording + long-distance information for the pattern-match checker. +issues: #27383, #20251 +mrs: !16203 ===================================== compiler/GHC/HsToCore/Arrows.hs ===================================== @@ -553,7 +553,7 @@ dsCmd ids local_vars stack_ty res_ty in_ty = envStackType env_ids stack_ty' discrims = map nlHsVar arg_ids (discrim_vars, matching_code) - <- matchWrapper (ArrowMatchCtxt match_ctxt) (Just discrims) match' + <- matchWrapper (ArrowMatchCtxt match_ctxt) (Just (map Var arg_ids)) match' core_body <- flip (bind_vars discrim_vars) matching_code <$> traverse dsLExpr discrims ===================================== compiler/GHC/HsToCore/Expr.hs ===================================== @@ -421,7 +421,7 @@ dsExpr (HsPragE _ (HsPragSCC _ cc) expr) dsExpr (HsCase ctxt discrim matches) = do { core_discrim <- dsLExpr discrim - ; ([discrim_var], matching_code) <- matchWrapper ctxt (Just [discrim]) matches + ; ([discrim_var], matching_code) <- matchWrapper ctxt (Just [core_discrim]) matches ; return (bindNonRec discrim_var core_discrim matching_code) } -- Pepe: The binds are in scope in the body but NOT in the binding group ===================================== compiler/GHC/HsToCore/Match.hs ===================================== @@ -761,7 +761,7 @@ Call @match@ with all of this information! matchWrapper :: HsMatchContextRn -- ^ For shadowing warning messages - -> Maybe [LHsExpr GhcTc] -- ^ Scrutinee(s) + -> Maybe [CoreExpr] -- ^ Already-desugared scrutinee(s) -- see Note [matchWrapper scrutinees] -> MatchGroup GhcTc (LHsExpr GhcTc) -- ^ Matches being desugared -> DsM ([Id], CoreExpr) -- ^ Results (usually passed to 'match') @@ -818,7 +818,7 @@ matchWrapper ctxt scrs (MG { mg_alts = L _ matches -- pmc for pattern synonyms -- See Note [Long-distance information] in GHC.HsToCore.Pmc - then addHsScrutTmCs (concat scrs) new_vars $ + then addCoreScrutTmCs (concat scrs) new_vars $ pmcMatches origin (DsMatchContext ctxt locn) new_vars matches -- When we're not doing PM checks on the match group, ===================================== compiler/GHC/HsToCore/Match.hs-boot ===================================== @@ -16,7 +16,7 @@ match :: [Id] matchWrapper :: HsMatchContextRn - -> Maybe [LHsExpr GhcTc] + -> Maybe [CoreExpr] -> MatchGroup GhcTc (LHsExpr GhcTc) -> DsM ([Id], CoreExpr) ===================================== compiler/GHC/HsToCore/Pmc.hs ===================================== @@ -34,7 +34,7 @@ module GHC.HsToCore.Pmc ( isMatchContextPmChecked, isMatchContextPmChecked_SinglePat, -- See Note [Long-distance information] - addTyCs, addCoreScrutTmCs, addHsScrutTmCs, getLdiNablas, + addTyCs, addCoreScrutTmCs, getLdiNablas, getNFirstUncovered ) where @@ -59,7 +59,6 @@ import GHC.Utils.Panic import GHC.Types.Var (EvVar, Var (..)) import GHC.Types.Id.Info import GHC.Tc.Utils.TcType (evVarPred) -import {-# SOURCE #-} GHC.HsToCore.Expr (dsLExpr) import GHC.HsToCore.Monad import GHC.Data.Bag import GHC.Data.OrdList @@ -684,12 +683,6 @@ addCoreScrutTmCs (scr:scrs) (x:xs) k addPhiCtsNablas nablas (unitBag (PhiCoreCt x scr)) addCoreScrutTmCs _ _ _ = panic "addCoreScrutTmCs: numbers of scrutinees and match ids differ" --- | 'addCoreScrutTmCs', but desugars the 'LHsExpr's first. -addHsScrutTmCs :: [LHsExpr GhcTc] -> [Id] -> DsM a -> DsM a -addHsScrutTmCs scrs vars k = do - scr_es <- traverse dsLExpr scrs - addCoreScrutTmCs scr_es vars k - {- Note [Long-distance information] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Consider @@ -716,8 +709,8 @@ To achieve similar reasoning in the coverage checker: which the call sites put into place with 'GHC.HsToCore.Monad.updPmNablas'. * Call sites also extend this set with facts from type-constraint dictionaries, - case scrutinees, etc. with the exported functions 'addTyCs', 'addCoreScrutTmCs' - and 'addHsScrutTmCs'. + case scrutinees, etc. with the exported functions 'addTyCs' and + 'addCoreScrutTmCs'. Note [Recovering from unsatisfiable pattern-matching constraints] ===================================== testsuite/tests/deSugar/should_compile/T27383.hs ===================================== @@ -0,0 +1,8 @@ +-- Regression test for #27383 (and #20251): deeply nested cases whose +-- scrutinees are themselves cases must desugar in polynomial (not +-- exponential) time. With the bug, even a few dozen nestings make +-- compilation time out. +module T27383 where + +zero :: Int +zero = (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case (case 0 of x100 -> x100) of x99 -> x99) of x98 -> x98) of x97 -> x97) of x96 -> x96) of x95 -> x95) of x94 -> x94) of x93 -> x93) of x92 -> x92) of x91 -> x91) of x90 -> x90) of x89 -> x89) of x88 -> x88) of x87 -> x87) of x86 -> x86) of x85 -> x85) of x84 -> x84) of x83 -> x83) of x82 -> x82) of x81 -> x81) of x80 -> x80) of x79 -> x79) of x78 -> x78) of x77 -> x77) of x76 -> x76) of x75 -> x75) of x74 -> x74) of x73 -> x73) of x72 -> x72) of x71 -> x71) of x70 -> x70) of x69 -> x69) of x68 -> x68) of x67 -> x67) of x66 -> x66) of x65 -> x65) of x64 -> x64) of x63 -> x63) of x62 -> x62) of x61 -> x61) of x60 -> x60) of x59 -> x59) of x58 -> x58) of x57 -> x57) of x56 -> x56) of x55 -> x55) of x54 -> x54) of x53 -> x53) of x52 -> x52) of x51 -> x51) of x50 -> x50) of x49 -> x49) of x48 -> x48) of x47 -> x47) of x46 -> x46) of x45 -> x45) of x44 -> x44) of x43 -> x43) of x42 -> x42) of x41 -> x41) of x40 -> x40) of x39 -> x39) of x38 -> x38) of x37 -> x37) of x36 -> x36) of x35 -> x35) of x34 -> x34) of x33 -> x33) of x32 -> x32) of x31 -> x31) of x30 -> x30) of x29 -> x29) of x28 -> x28) of x27 -> x27) of x26 -> x26) of x25 -> x25) of x24 -> x24) of x23 -> x23) of x22 -> x22) of x21 -> x21) of x20 -> x20) of x19 -> x19) of x18 -> x18) of x17 -> x17) of x16 -> x16) of x15 -> x15) of x14 -> x14) of x13 -> x13) of x12 -> x12) of x11 -> x11) of x10 -> x10) of x9 -> x9) of x8 -> x8) of x7 -> x7) of x6 -> x6) of x5 -> x5) of x4 -> x4) of x3 -> x3) of x2 -> x2) of x1 -> x1) ===================================== testsuite/tests/deSugar/should_compile/all.T ===================================== @@ -116,3 +116,4 @@ test('T22719', normal, compile, ['-ddump-simpl -dsuppress-uniques -dno-typeable- test('T23550', normal, compile, ['']) test('T24489', normal, compile, ['-O']) test('T25996', normal, compile, ['']) +test('T27383', normal, compile, ['']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/331843b80f79c4ff5df5056a0a2f81a… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/331843b80f79c4ff5df5056a0a2f81a… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T17833] Seed the simplifier's in-scope set for open expressions
by Sebastian Graf (＠sgraf812) 17 Jun '26

17 Jun '26

Sebastian Graf pushed to branch wip/T17833 at Glasgow Haskell Compiler / GHC Commits: 0cf50721 by Sebastian Graf at 2026-06-16T23:12:08+02:00 Seed the simplifier's in-scope set for open expressions simplifyExpr simplifies expressions typed at the GHCi prompt and the results of Template Haskell splices. Such an expression may be open: at a GHCi debugger breakpoint its free variables include RuntimeUnk skolems standing for as-yet-unknown types. The simplifier began with an in-scope set holding only the wildcard binder, so when it instantiated the unsafeCoerce# wrapper that GHCi builds around a result, it formed a substitution whose range mentioned a free skolem that was not in scope. That breaks the substitution invariant and, in a compiler built with assertions, trips substTy's sanity check. Seed the initial in-scope set with the free variables of the expression. For a closed expression this adds nothing. See Note [Seed the in-scope set for open expressions]. Fixes #17833 and its duplicate #21118. - - - - - 2 changed files: - compiler/GHC/Core/Opt/Simplify.hs - testsuite/tests/ghci.debugger/scripts/all.T Changes: ===================================== compiler/GHC/Core/Opt/Simplify.hs ===================================== @@ -14,6 +14,7 @@ import GHC.Core.Rules import GHC.Core.Ppr ( pprCoreBindings, pprCoreExpr ) import GHC.Core.Opt.OccurAnal ( occurAnalysePgm, occurAnalyseExpr ) import GHC.Core.Stats ( coreBindsSize, coreBindsStats, exprSize ) +import GHC.Core.FVs ( exprFreeVars ) import GHC.Core.Utils ( mkTicks, stripTicksTop ) import GHC.Core.Lint ( LintPassResultConfig, dumpPassResult, lintPassResult ) import GHC.Core.Opt.Simplify.Iteration ( simplTopBinds, simplExpr, simplImpRules ) @@ -74,7 +75,10 @@ simplifyExpr logger euc opts expr ; let fam_envs = ( eps_fam_inst_env eps , extendFamInstEnvList emptyFamInstEnv $ se_fam_inst opts ) - simpl_env = mkSimplEnv (se_mode opts) fam_envs + -- See Note [Seed the in-scope set for open expressions] + simpl_env = setInScopeSet base_env + (getInScope base_env `extendInScopeSetSet` exprFreeVars expr) + base_env = mkSimplEnv (se_mode opts) fam_envs top_env_cfg = se_top_env_cfg opts read_eps_rules = eps_rule_base <$> eucEPS euc read_ruleenv = updExternalPackageRules emptyRuleEnv <$> read_eps_rules @@ -94,6 +98,49 @@ simplifyExpr logger euc opts expr ; return expr' } +{- Note [Seed the in-scope set for open expressions] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +An invariant of the Simplifier is that the in-scope set contains all the free +variables of the expression being simplified. Why? So that the Simplifier +never invents a "fresh" binder that accidentally captures one of those free +variables. + +'simplifyExpr' establishes that invariant by initialising the in-scope set with +the free variables of the expression it is given. For a closed expression this +adds nothing. + +But how can 'simplifyExpr' be handed an /open/ expression in the first place? +The whole-module pipeline never does so: 'simplifyPgm' only ever simplifies +closed bindings. The one caller that can is 'hscCompileCoreExpr' (in +GHC.Driver.Main.Passes), which compiles a single Core expression, and is itself +reached from just two places: + + * GHCi, for an expression typed at the prompt, and in particular in the + debugger (see below); + * Template Haskell, when running a splice (see GHC.Tc.Gen.Splice). + +So this is never on the critical path for mainstream compilation. + +Here is how the debugger hands us an open expression (test break006). We are +stopped at a breakpoint in + mymap f (x:xs) = f x : ... +where the debugger knows that 'x :: Int' but not yet the result type of 'f'. So +it invents a RuntimeUnk skolem 'a' and gives 'f :: Int -> a'. The user then +types + let y = f x +GHCi type-checks that and, to hand the result back to the interpreter (see +GHC.Tc.Module.tcGhciStmts), wraps it as + returnIO @[Any] [unsafeCoerce# @LiftedRep @LiftedRep @a @Any y] +in which the skolem 'a' is free. + +When the Simplifier instantiates that 'unsafeCoerce#', it builds a substitution +mapping unsafeCoerce#'s quantified type variables to (LiftedRep, LiftedRep, a, +Any), whose range therefore mentions 'a'. The in-scope set of a substitution +must contain the free variables of its range (see Note [The substitution +invariant] in GHC.Core.TyCo.Subst). Without the seeding above that invariant is +broken, and in a compiler built with assertions substTy's sanity check fails +(#17833, and its duplicate #21118). -} + simplExprGently :: SimplEnv -> CoreExpr -> SimplM CoreExpr -- ^ Simplifies an expression by doing occurrence analysis, then simplification, -- and repeating (twice currently), because one pass alone leaves tons of crud. ===================================== testsuite/tests/ghci.debugger/scripts/all.T ===================================== @@ -52,8 +52,7 @@ test('break002', extra_files(['../Test2.hs']), ghci_script, ['break002.script']) test('break003', extra_files(['../Test3.hs']), ghci_script, ['break003.script']) test('break005', extra_files(['../QSort.hs']), ghci_script, ['break005.script']) test('break006', - [ when(compiler_debugged(), expect_broken(17833)), - extra_files(['../Test3.hs'])], + [extra_files(['../Test3.hs'])], ghci_script, ['break006.script']) test('break007', extra_files(['Break007.hs']), ghci_script, ['break007.script']) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/0cf50721a9c5fc4e67234b66bb6de39… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/0cf50721a9c5fc4e67234b66bb6de39… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/az/exactprint-annotation-rationalisation] 19 commits: Implement CLC proposal #378
by Alan Zimmerman (＠alanz) 17 Jun '26

17 Jun '26

Alan Zimmerman pushed to branch wip/az/exactprint-annotation-rationalisation at Glasgow Haskell Compiler / GHC Commits: bab37cc6 by konsumlamm at 2026-06-13T19:10:21+02:00 Implement CLC proposal #378 Add `Data.Double` and `Data.Float` modules Document that GHC uses IEEE 754 - - - - - fb5246ad by fendor at 2026-06-15T18:07:23-04:00 Drop `preloadClosure` from `UnitState` It is always hard-coded to the same value. Backpack Unit instantiation isn't using it any more. Allows us to simplify the API and get rid of `improveUnit`. - - - - - 291ce3aa by ARATA Mizuki at 2026-06-15T18:08:26-04:00 RISC-V NCG: Zero-extend the result of castFloatToWord32 According to the ISA manual, FMV.X.W sign-extends the result. We need to truncate the result to avoid creating an exotic Word32 value. Fixes #27300 - - - - - 011be91f by ARATA Mizuki at 2026-06-15T18:08:26-04:00 RISC-V NCG: Treat d28-d31 (ft8-ft11) as caller-saved According to the calling convention, the registers d28-d31 (ft8-ft11) are caller-saved. Fixes #27306 - - - - - e8a54713 by ARATA Mizuki at 2026-06-15T18:08:26-04:00 RISC-V NCG: Set rounding mode when emitting `truncate` If we omit the rounding mode for `fcvt`, `dyn` will be used. We do not want that for `truncate`, so we set `rtz`. In other places, we set `rne` because we do not use the dynamic rounding mode. Fixes #27303 - - - - - 9438bec7 by Zubin Duggal at 2026-06-15T18:09:11-04:00 rts: fix validate build with gcc 16. `__attribute__((regparm(1)))` is ignored on x86_64 and now gcc warns that it is ignored: rts/sm/Evac.h:35:1: error: error: ‘regparm’ attribute ignored [-Werror=attributes] See https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ccead81bbc39668376eb5cf47066a… Fixes #27366 - - - - - 893e6133 by Andrew Lelechenko at 2026-06-15T23:55:36+01:00 base: more NonEmpty zips CLC proposal: https://github.com/haskell/core-libraries-committee/issues/409 - - - - - 1314f2fd by David Eichmann at 2026-06-16T05:46:52-04:00 Hadrian: fix ghc-internal .def file name - - - - - 7f72bcb3 by mangoiv at 2026-06-16T05:47:39-04:00 compiler: ignore camelCase and Eta reduce hlint hints These do not cohere with the style used in GHC. After disabling them, hlint lints are much less noisy again. - - - - - 842bef9f by Alan Zimmerman at 2026-06-16T05:48:25-04:00 EPA: Use standard type family declaration for Anno - - - - - b6d7b3dd by Alan Zimmerman at 2026-06-16T20:13:36+01:00 TTG: Add extension points to HsConDetails Extend HsConDetails as data HsConDetails p arg rec = PrefixCon !(XPrefixCon p) [arg] -- C @t1 @t2 p1 p2 p3 | RecCon !(XRecCon p) rec -- C { x = p1, y = p2 } | InfixCon !(XInfixCon p) arg arg -- p1 `C` p2 | XHsConDetails !(XXHsConDetails p) type family XPrefixCon p type family XRecCon p type family XInfixCon p type family XXHsConDetails p - - - - - 3cb48ae7 by Alan Zimmerman at 2026-06-16T20:15:17+01:00 EPA: remove LocatedLI / SrcSpanAnnLI These were used for module export lists, and import decl lists. Replace them with direct capture of the relevant EP Annotations in HsModule and ImportDecl annotation extension points. Also use the HsConDetails RecCon extension point to capture the braces in a record constructor - - - - - c91d8993 by Alan Zimmerman at 2026-06-16T20:15:17+01:00 EPA: Remove LocatedC / SrcSpanAnnC Used for contexts - - - - - 3e87ac98 by Alan Zimmerman at 2026-06-16T20:15:17+01:00 EPA: Harmonise HsQual/HsQualTy TTG extension annotations - - - - - d0b778c7 by Alan Zimmerman at 2026-06-16T20:15:17+01:00 EPA Remove LocatedLC / LocatedLS LocatedLC/LocatedLS were unused - - - - - efa5ed6a by Alan Zimmerman at 2026-06-16T20:15:17+01:00 EPA: Remove LocatedLW from LStmtLR - - - - - 29c665a0 by Alan Zimmerman at 2026-06-16T20:15:17+01:00 EPA: Remove LocatedLW from MatchGroup This is the last usage of LocatedLW / SrcSpanAnnLW - - - - - 8d7a6cc6 by Alan Zimmerman at 2026-06-16T20:15:17+01:00 EPA: Move the 'where' annotation for PatSynBind This allows us to move it out of the MatchGroup exact print annotation too - - - - - 140d9655 by Alan Zimmerman at 2026-06-16T22:09:52+01:00 EPA: Replace AnnListItem with simply [TrailingAnn] Remove the unnecessary wrapper around a single field. - - - - - 133 changed files: - + changelog.d/T27308 - compiler/.hlint.yaml - compiler/GHC/CmmToAsm/RV64/CodeGen.hs - compiler/GHC/CmmToAsm/RV64/Instr.hs - compiler/GHC/CmmToAsm/RV64/Ppr.hs - compiler/GHC/CmmToAsm/RV64/Regs.hs - compiler/GHC/Data/BooleanFormula.hs - compiler/GHC/Data/List/NonEmpty.hs - compiler/GHC/Driver/Backpack.hs - compiler/GHC/Hs.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Dump.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/ImpExp.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Pat.hs - compiler/GHC/Hs/Stats.hs - compiler/GHC/Hs/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Match/Constructor.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/HsToCore/Ticks.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Load.hs - compiler/GHC/Iface/Recomp.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Annotation.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Parser/PostProcess/Haddock.hs - compiler/GHC/Parser/Types.hs - compiler/GHC/Rename/Bind.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/Utils.hs - compiler/GHC/Tc/Deriv.hs - compiler/GHC/Tc/Deriv/Generate.hs - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/Arrow.hs - compiler/GHC/Tc/Gen/Do.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/Sig.hs - compiler/GHC/Tc/Module.hs - compiler/GHC/Tc/TyCl.hs - compiler/GHC/Tc/TyCl/PatSyn.hs - compiler/GHC/Tc/TyCl/Utils.hs - compiler/GHC/Tc/Utils/Backpack.hs - compiler/GHC/Tc/Zonk/Type.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Unit.hs - compiler/GHC/Unit/State.hs - compiler/GHC/Unit/Types.hs - compiler/Language/Haskell/Syntax.hs - compiler/Language/Haskell/Syntax/Binds.hs - compiler/Language/Haskell/Syntax/Decls.hs - compiler/Language/Haskell/Syntax/Expr.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/ImpExp.hs - compiler/Language/Haskell/Syntax/Pat.hs - compiler/Language/Haskell/Syntax/Type.hs - docs/users_guide/bugs.rst - ghc/GHCi/UI.hs - hadrian/src/Rules/Rts.hs - libraries/base/base.cabal.in - libraries/base/changelog.md - + libraries/base/src/Data/Double.hs - + libraries/base/src/Data/Float.hs - libraries/base/src/Data/List/NonEmpty.hs - libraries/ghc-internal/src/GHC/Internal/Float.hs - rts/sm/Evac.h - testsuite/tests/codeGen/should_run/T16617.hs - testsuite/tests/codeGen/should_run/T16617.stdout - testsuite/tests/ghc-api/T25121_status.stdout - testsuite/tests/ghc-api/exactprint/T22919.stderr - testsuite/tests/ghc-api/exactprint/Test20239.stderr - testsuite/tests/ghc-api/exactprint/ZeroWidthSemi.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T17544.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T17544_kw.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T24221.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/module/mod185.stderr - testsuite/tests/parser/should_compile/DumpParsedAst.stderr - testsuite/tests/parser/should_compile/DumpParsedAstComments.stderr - testsuite/tests/parser/should_compile/DumpRenamedAst.stderr - testsuite/tests/parser/should_compile/DumpSemis.stderr - testsuite/tests/parser/should_compile/DumpTypecheckedAst.stderr - testsuite/tests/parser/should_compile/KindSigs.stderr - testsuite/tests/parser/should_compile/T14189.stderr - testsuite/tests/parser/should_compile/T15279.stderr - testsuite/tests/parser/should_compile/T15323.stderr - testsuite/tests/parser/should_compile/T20452.stderr - testsuite/tests/parser/should_compile/T20718.stderr - testsuite/tests/parser/should_compile/T20718b.stderr - testsuite/tests/parser/should_compile/T20846.stderr - testsuite/tests/parser/should_compile/T23315/T23315.stderr - testsuite/tests/parser/should_compile/all.T - testsuite/tests/printer/AnnotationNoListTuplePuns.stdout - testsuite/tests/printer/Makefile - testsuite/tests/printer/T18791.stderr - testsuite/tests/printer/Test20297.stdout - testsuite/tests/printer/Test24533.stdout - testsuite/tests/typecheck/should_compile/T15242.stderr - testsuite/tests/typecheck/should_compile/all.T - utils/check-exact/ExactPrint.hs - utils/check-exact/Main.hs - utils/check-exact/Transform.hs - utils/check-exact/Utils.hs - utils/haddock/haddock-api/src/Haddock/Backends/Hoogle.hs - utils/haddock/haddock-api/src/Haddock/Backends/LaTeX.hs - utils/haddock/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs - utils/haddock/haddock-api/src/Haddock/Convert.hs - utils/haddock/haddock-api/src/Haddock/GhcUtils.hs - utils/haddock/haddock-api/src/Haddock/Interface/Create.hs - utils/haddock/haddock-api/src/Haddock/Interface/LexParseRn.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 - utils/haddock/html-test/ref/Hash.html - utils/haddock/html-test/ref/Test.html - utils/haddock/html-test/ref/TypeFamilies3.html The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/79c8e7d059e35a1aad102e997b91ad… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/79c8e7d059e35a1aad102e997b91ad… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/T27383
by Sebastian Graf (＠sgraf812) 17 Jun '26

17 Jun '26

Sebastian Graf pushed new branch wip/T27383 at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/T27383 You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 6 commits: Fix two issues in the documentation of pipeline interruption
by Marge Bot (＠marge-bot) 17 Jun '26

17 Jun '26

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: f6d30767 by Wolfgang Jeltsch at 2026-06-16T15:32:34-04:00 Fix two issues in the documentation of pipeline interruption One issue is a typo (“interreuptible”), the other one the lack of an end of a sentence, which has been reconstructed from the message of 633bbc1fd4762a2bb73ba1c5b9e0c279f1dd3c40, the commit that introduced said documentation. - - - - - a3fa10e0 by Christian Georgii at 2026-06-16T15:33:26-04:00 Find plugins in sibling home units in multiple-home-unit sessions In a multiple-home-unit session (e.g. `cabal repl --enable-multi-repl` or HLS), enabling a plugin with -fplugin that is defined in (or reexported by) another home unit failed with a "hidden package" error. The plugin module finder only searched the current home unit and the registered external packages, never the sibling home units. findPluginModuleNoHsc now searches the home units that the current home unit depends on, following module reexports and respecting hidden modules, exactly as ordinary import resolution does in findImportedModuleNoHsc. To avoid two divergent copies of this logic, the shared home-unit search (the current home unit first, then its dependencies in priority order, with the accompanying ordering invariant) is extracted into findHomeModuleAmongDeps, which both findImportedModuleNoHsc and findPluginModuleNoHsc now call. Add testsuite/tests/driver/multipleHomeUnits/plugin01, which loads a plugin as byte-code from a sibling home unit, and plugin02, in which the consumer enables a plugin reexported by a sibling home unit without depending on the plugin's own home unit directly. Fixes #27349 - - - - - d6b2183f by Ian-Woo Kim at 2026-06-16T16:05:29-04:00 Make the order of usages deterministic It has been observed that the ordering of usages can be non-determinstic in parallel builds. Therefore, this contribution introduces sorting of usages based on a platform- and race-independent sorting criterion. Resolves #26877. Co-authored-by: Wolfgang Jeltsch <wolfgang(a)well-typed.com> - - - - - 47db80e5 by Wolfgang Jeltsch at 2026-06-16T16:05:29-04:00 Change the descriptions of two existing changelog entries The descriptions now describe the changes in a user-friendly manner, as opposed to describing the contributions that led to these changes in a developer-friendly manner. - - - - - 7575a005 by Ian Duncan at 2026-06-16T16:05:34-04:00 AArch64: use SXTH, not SXTW, for W32 signExtendReg signExtendReg was using SXTH (sign-extend halfword, 16-bit) for W32-to-W64 sign extension. This should be SXTW (sign-extend word, 32-bit). SXTH only sign-extends the lower 16 bits, producing wrong results for 32-bit values whose bit 15 differs from bit 31. Other fixes: - At sub-W64, code gen for MO_S_Mul2 should use W32 registers for SMULL source operands as per the ARM spec (SMULL Xd, Wn, Wm), and not W64. - Ensure signExtendReg uses the source width for the source operand in SXTW/SXTH/SXTB instructions. GNU as requires sxtw Xd,Wn (not sxtw Xd,Xn), while LLVM's integrated assembler on macOS is lenient. - Fix overflow flag computation for `MO_S_Mul2`. The overflow bit was exactly inverted for sub-W64 operands. Fixes #26978 and #27047 - - - - - 798b1ee0 by Igor Ranieri at 2026-06-16T16:05:35-04:00 haddock: Update CONTRIBUTING with missing step, add missing test dependency - - - - - 36 changed files: - .gitlab-ci.yml - + changelog.d/T26978 - + changelog.d/T27047 - + changelog.d/deterministic-usage-order - + changelog.d/fix-plugin-finder-multi-home-unit.md - changelog.d/module-graph-reuse-in-downsweep - changelog.d/more-efficient-home-unit-imports-finding - compiler/GHC/CmmToAsm/AArch64/CodeGen.hs - compiler/GHC/CmmToAsm/AArch64/Instr.hs - compiler/GHC/CmmToAsm/AArch64/Ppr.hs - compiler/GHC/HsToCore/Usage.hs - compiler/GHC/Unit/Finder.hs - compiler/GHC/Unit/Module/Deps.hs - + testsuite/tests/codeGen/should_gen_asm/aarch64-sxth-mul2.asm - + testsuite/tests/codeGen/should_gen_asm/aarch64-sxth-mul2.cmm - + testsuite/tests/codeGen/should_gen_asm/aarch64-sxtw.asm - + testsuite/tests/codeGen/should_gen_asm/aarch64-sxtw.cmm - testsuite/tests/codeGen/should_gen_asm/all.T - + testsuite/tests/codeGen/should_run/aarch64-sxtw-cmm.cmm - + testsuite/tests/codeGen/should_run/aarch64-sxtw-run.hs - + testsuite/tests/codeGen/should_run/aarch64-sxtw-run.stdout - testsuite/tests/codeGen/should_run/all.T - + testsuite/tests/driver/multipleHomeUnits/plugin01/all.T - + testsuite/tests/driver/multipleHomeUnits/plugin01/appunit - + testsuite/tests/driver/multipleHomeUnits/plugin01/p/MyPlugin.hs - + testsuite/tests/driver/multipleHomeUnits/plugin01/pluginunit - + testsuite/tests/driver/multipleHomeUnits/plugin01/q/App.hs - + testsuite/tests/driver/multipleHomeUnits/plugin02/all.T - + testsuite/tests/driver/multipleHomeUnits/plugin02/appunit - + testsuite/tests/driver/multipleHomeUnits/plugin02/p/MyPlugin.hs - + testsuite/tests/driver/multipleHomeUnits/plugin02/pluginunit - + testsuite/tests/driver/multipleHomeUnits/plugin02/q/App.hs - + testsuite/tests/driver/multipleHomeUnits/plugin02/r/RexLib.hs - + testsuite/tests/driver/multipleHomeUnits/plugin02/reexportunit - utils/haddock/CONTRIBUTING.md - utils/haddock/haddock-test/haddock-test.cabal The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/678ee3559c958e9e720ba48df4bcc2… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/678ee3559c958e9e720ba48df4bcc2… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] Find plugins in sibling home units in multiple-home-unit sessions
by Marge Bot (＠marge-bot) 17 Jun '26

17 Jun '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: a3fa10e0 by Christian Georgii at 2026-06-16T15:33:26-04:00 Find plugins in sibling home units in multiple-home-unit sessions In a multiple-home-unit session (e.g. `cabal repl --enable-multi-repl` or HLS), enabling a plugin with -fplugin that is defined in (or reexported by) another home unit failed with a "hidden package" error. The plugin module finder only searched the current home unit and the registered external packages, never the sibling home units. findPluginModuleNoHsc now searches the home units that the current home unit depends on, following module reexports and respecting hidden modules, exactly as ordinary import resolution does in findImportedModuleNoHsc. To avoid two divergent copies of this logic, the shared home-unit search (the current home unit first, then its dependencies in priority order, with the accompanying ordering invariant) is extracted into findHomeModuleAmongDeps, which both findImportedModuleNoHsc and findPluginModuleNoHsc now call. Add testsuite/tests/driver/multipleHomeUnits/plugin01, which loads a plugin as byte-code from a sibling home unit, and plugin02, in which the consumer enables a plugin reexported by a sibling home unit without depending on the plugin's own home unit directly. Fixes #27349 - - - - - 14 changed files: - + changelog.d/fix-plugin-finder-multi-home-unit.md - compiler/GHC/Unit/Finder.hs - + testsuite/tests/driver/multipleHomeUnits/plugin01/all.T - + testsuite/tests/driver/multipleHomeUnits/plugin01/appunit - + testsuite/tests/driver/multipleHomeUnits/plugin01/p/MyPlugin.hs - + testsuite/tests/driver/multipleHomeUnits/plugin01/pluginunit - + testsuite/tests/driver/multipleHomeUnits/plugin01/q/App.hs - + testsuite/tests/driver/multipleHomeUnits/plugin02/all.T - + testsuite/tests/driver/multipleHomeUnits/plugin02/appunit - + testsuite/tests/driver/multipleHomeUnits/plugin02/p/MyPlugin.hs - + testsuite/tests/driver/multipleHomeUnits/plugin02/pluginunit - + testsuite/tests/driver/multipleHomeUnits/plugin02/q/App.hs - + testsuite/tests/driver/multipleHomeUnits/plugin02/r/RexLib.hs - + testsuite/tests/driver/multipleHomeUnits/plugin02/reexportunit Changes: ===================================== changelog.d/fix-plugin-finder-multi-home-unit.md ===================================== @@ -0,0 +1,7 @@ +section: compiler +synopsis: Find plugins defined in sibling home units in multiple-home-unit sessions +issues: #27349 +mrs: !16156 +description: { + In a multiple-home-unit session (e.g. ``cabal repl --enable-multi-repl`` or HLS), the plugin finder now also searches the home units that the current home unit depends on, following module reexports along the way, so a ``-fplugin`` defined in (or reexported by) a sibling home unit is found and loaded instead of failing as a hidden package. +} ===================================== compiler/GHC/Unit/Finder.hs ===================================== @@ -231,36 +231,14 @@ findImportedModuleNoHsc fc fopts ue home_module_name_providers_map mb_home_unit NoPackage (panic "findImportedModule: no home-unit") home_pkg_import :: (UnitId, FinderOpts) -> IO FindResult - home_pkg_import (uid, opts) - -- If the module is reexported, then look for it as if it was from the - -- perspective of that package which reexports it. - | Just real_mod_name - <- lookupUniqMap (finder_reexportedModules opts) mod_name - = findImportedModuleNoHsc fc opts ue home_module_name_providers_map - (Just $ DefiniteHomeUnit uid Nothing) - real_mod_name - NoPkgQual - | elementOfUniqSet mod_name (finder_hiddenModules opts) - = return (mkHomeHidden uid) - | otherwise - = findHomePackageModule fc opts uid mod_name - - any_home_import :: IO FindResult - any_home_import = foldr1 orIfNotFound $ - home_import :| map home_pkg_import other_fopts - -- Do not try to be smart and change this to `foldr orIfNotFound home_import - -- (map home_pkg_import other_fopts)`, as that would not be the same. - -- `home_import` is first because we need to first look within the current - -- unit before looking at the other units in order. + home_pkg_import = findHomeUnitDepModule fc ue home_module_name_providers_map mod_name pkg_import :: IO FindResult pkg_import = findExposedPackageModule fc fopts unit_state mod_name mb_pkg unqual_import :: IO FindResult - unqual_import - = any_home_import - `orIfNotFound` - findExposedPackageModule fc fopts unit_state mod_name NoPkgQual + unqual_import = findHomeOrRegularPackageModule fc fopts ue + home_module_name_providers_map mb_home_unit mod_name unit_state :: UnitState unit_state = case mb_home_unit_id of @@ -268,22 +246,44 @@ findImportedModuleNoHsc fc fopts ue home_module_name_providers_map mb_home_unit Just home_unit_id -> HUG.homeUnitEnv_units $ ue_findHomeUnitEnv home_unit_id ue - home_unit_deps :: Set UnitId - home_unit_deps = homeUnitDepends unit_state + other_fopts :: [(UnitId, FinderOpts)] + other_fopts = homeUnitDepsFinderOpts ue home_module_name_providers_map + unit_state mod_name + +-- | Locate a plugin module requested by the user, for a compiler +-- plugin. This consults the same set of exposed packages as +-- 'findImportedModule', unless @-hide-all-plugin-packages@ or +-- @-plugin-package@ are specified. +findPluginModuleNoHsc + :: FinderCache + -> FinderOpts + -> UnitEnv + -> HomeModuleNameProvidersMap + -> Maybe HomeUnit + -> ModuleName + -> IO FindResult +findPluginModuleNoHsc fc fopts ue home_module_name_providers_map mb_home_unit@(Just home_unit) mod_name = + findHomeModuleAmongDeps fc fopts ue home_module_name_providers_map + mb_home_unit mod_name + `orIfNotFound` + findExposedPluginPackageModule fc fopts unit_state mod_name + where + unit_state = HUG.homeUnitEnv_units $ + ue_findHomeUnitEnv (homeUnitId home_unit) ue +findPluginModuleNoHsc fc fopts ue _ Nothing mod_name = + findExposedPluginPackageModule fc fopts (ue_homeUnitState ue) mod_name - ranked_home_unit_deps :: [UnitId] - ranked_home_unit_deps = rankedHomeUnitDeps home_module_name_providers_map - mod_name - home_unit_deps +findPluginModule :: HscEnv -> ModuleName -> IO FindResult +findPluginModule hsc_env mod_name = do + let fc = hsc_FC hsc_env + mb_home_unit = hsc_home_unit_maybe hsc_env + home_module_name_providers_map = + mgHomeModuleNameProvidersMap (hsc_mod_graph hsc_env) + findPluginModuleNoHsc fc (initFinderOpts (hsc_dflags hsc_env)) + (hsc_unit_env hsc_env) home_module_name_providers_map mb_home_unit mod_name - other_fopts :: [(UnitId, FinderOpts)] - other_fopts - = [ - (uid, opts) | - uid <- ranked_home_unit_deps, - let opts = initFinderOpts $ - homeUnitEnv_dflags (ue_findHomeUnitEnv uid ue) - ] +-- ----------------------------------------------------------------------------- +-- Home Module Finder Helpers -- | Yields the unit IDs from the given set as a list with those that refer to -- providers of the given home module name coming first. This is to prioritize @@ -323,24 +323,93 @@ rankedHomeUnitDeps home_module_name_providers_map mod_name home_unit_deps uncached_deps :: Set UnitId uncached_deps = Set.difference home_unit_deps cached_providers --- | Locate a plugin module requested by the user, for a compiler --- plugin. This consults the same set of exposed packages as --- 'findImportedModule', unless @-hide-all-plugin-packages@ or --- @-plugin-package@ are specified. -findPluginModuleNoHsc :: FinderCache -> FinderOpts -> UnitState -> Maybe HomeUnit -> ModuleName -> IO FindResult -findPluginModuleNoHsc fc fopts units (Just home_unit) mod_name = - findHomeModule fc fopts home_unit mod_name - `orIfNotFound` - findExposedPluginPackageModule fc fopts units mod_name -findPluginModuleNoHsc fc fopts units Nothing mod_name = - findExposedPluginPackageModule fc fopts units mod_name +-- | The 'FinderOpts' of the home units that should be searched, sorted by +-- priority order specified by 'rankedHomeUnitDeps'. +homeUnitDepsFinderOpts + :: UnitEnv + -> HomeModuleNameProvidersMap + -> UnitState -- ^ unit state of the requesting home unit + -> ModuleName + -> [(UnitId, FinderOpts)] +homeUnitDepsFinderOpts ue home_module_name_providers_map unit_state mod_name = + [ (uid, initFinderOpts (ue_unitFlags uid ue)) + | uid <- rankedHomeUnitDeps home_module_name_providers_map mod_name + (homeUnitDepends unit_state) + ] + +-- | Search for @mod_name@ in the given home unit. +findHomeUnitDepModule + :: FinderCache + -> UnitEnv + -> HomeModuleNameProvidersMap + -> ModuleName + -> (UnitId, FinderOpts) + -> IO FindResult +findHomeUnitDepModule fc ue home_module_name_providers_map mod_name (uid, opts) + -- If the module is reexported, then look for it as if it was from the + -- perspective of the package which reexports it. + | Just real_mod_name + <- lookupUniqMap (finder_reexportedModules opts) mod_name + = findHomeOrRegularPackageModule fc opts ue home_module_name_providers_map + (Just $ DefiniteHomeUnit uid Nothing) + real_mod_name + | elementOfUniqSet mod_name (finder_hiddenModules opts) + = return (mkHomeHidden uid) + | otherwise + = findHomePackageModule fc opts uid mod_name + +-- | Search for @mod_name@ among the home units: first the current home unit, +-- then the home units it depends on, in priority order, following module +-- reexports along the way (see 'findHomeUnitDepModule'). Yields the first +-- successful result. +findHomeModuleAmongDeps + :: FinderCache + -> FinderOpts + -> UnitEnv + -> HomeModuleNameProvidersMap + -> Maybe HomeUnit + -> ModuleName + -> IO FindResult +findHomeModuleAmongDeps fc fopts ue home_module_name_providers_map mb_home_unit mod_name = + foldr1 orIfNotFound (home_import :| map home_pkg_import other_fopts) + -- Do not try to be smart and change this to `foldr orIfNotFound home_import + -- (map home_pkg_import other_fopts)`, as that would not be the same. + -- `home_import` is first because we need to first look within the current + -- unit before looking at the other units in order. + where + home_import = case mb_home_unit of + Just home_unit -> findHomeModule fc fopts home_unit mod_name + Nothing -> pure $ + NoPackage (panic "findHomeModuleAmongDeps: no home-unit") + home_pkg_import = findHomeUnitDepModule fc ue home_module_name_providers_map mod_name -findPluginModule :: HscEnv -> ModuleName -> IO FindResult -findPluginModule hsc_env mod_name = do - let fc = hsc_FC hsc_env - let units = hsc_units hsc_env - let mb_home_unit = hsc_home_unit_maybe hsc_env - findPluginModuleNoHsc fc (initFinderOpts (hsc_dflags hsc_env)) units mb_home_unit mod_name + unit_state = case homeUnitId <$> mb_home_unit of + Nothing -> ue_homeUnitState ue + Just home_unit_id -> HUG.homeUnitEnv_units $ + ue_findHomeUnitEnv home_unit_id ue + other_fopts = homeUnitDepsFinderOpts ue home_module_name_providers_map + unit_state mod_name + +-- | Search the home-unit graph and otherwise the regular exposed package +-- database. +findHomeOrRegularPackageModule + :: FinderCache + -> FinderOpts + -> UnitEnv + -> HomeModuleNameProvidersMap + -> Maybe HomeUnit + -> ModuleName + -> IO FindResult +findHomeOrRegularPackageModule fc fopts ue home_module_name_providers_map mb_home_unit mod_name = + findHomeModuleAmongDeps fc fopts ue home_module_name_providers_map + mb_home_unit mod_name + `orIfNotFound` + findExposedPackageModule fc fopts unit_state mod_name NoPkgQual + where + unit_state = case homeUnitId <$> mb_home_unit of + Nothing -> ue_homeUnitState ue + Just home_unit_id -> HUG.homeUnitEnv_units $ + ue_findHomeUnitEnv home_unit_id ue -- | A version of findExactModule which takes the exact parts of the HscEnv it needs ===================================== testsuite/tests/driver/multipleHomeUnits/plugin01/all.T ===================================== @@ -0,0 +1,14 @@ +# A plugin (MyPlugin, in home unit plugin-0) is enabled by a module (App, in +# home unit app-0) belonging to a *different* home unit in the same session. +# Resolving -fplugin must search sibling home units; previously the plugin +# finder only looked at the current home unit and registered external packages, +# so this failed with "Could not load module 'MyPlugin' ... hidden package". +# +# -fbyte-code-and-object-code -fprefer-byte-code makes the plugin load as +# byte-code from its (interpreted) home unit, mirroring how a multiple-home-unit +# session is driven by 'cabal repl --enable-multi-repl' and HLS. +test('multipleHomeUnits_plugin01', + [req_plugins, extra_files(['p/', 'q/', 'pluginunit', 'appunit'])], + multiunit_compile, + [['pluginunit', 'appunit'], + '-v0 -fbyte-code-and-object-code -fprefer-byte-code']) ===================================== testsuite/tests/driver/multipleHomeUnits/plugin01/appunit ===================================== @@ -0,0 +1 @@ +-working-dir q App -this-unit-id app-0 -this-package-name app -package-id plugin-0 ===================================== testsuite/tests/driver/multipleHomeUnits/plugin01/p/MyPlugin.hs ===================================== @@ -0,0 +1,8 @@ +module MyPlugin (plugin) where + +import GHC.Plugins + +-- A no-op plugin: it makes no changes to the program but, to run at all, it +-- must be found and loaded by the consumer module's compilation. +plugin :: Plugin +plugin = defaultPlugin { pluginRecompile = purePlugin } ===================================== testsuite/tests/driver/multipleHomeUnits/plugin01/pluginunit ===================================== @@ -0,0 +1 @@ +-working-dir p MyPlugin -this-unit-id plugin-0 -this-package-name plugin -package ghc ===================================== testsuite/tests/driver/multipleHomeUnits/plugin01/q/App.hs ===================================== @@ -0,0 +1,8 @@ +{-# OPTIONS_GHC -fplugin=MyPlugin #-} +module App where + +-- The plugin 'MyPlugin' lives in a *sibling* home unit (plugin-0), not in a +-- registered package. Resolving -fplugin must therefore search sibling home +-- units, just like an ordinary import does. +app :: () +app = () ===================================== testsuite/tests/driver/multipleHomeUnits/plugin02/all.T ===================================== @@ -0,0 +1,16 @@ +# A plugin (MyPlugin) lives in home unit plugin-0 and is *reexported* by a +# second home unit, reexport-0 (via -reexported-module). The consumer module +# App, in home unit app-0, enables it with -fplugin=MyPlugin but depends only on +# reexport-0, not on plugin-0 directly. Resolving -fplugin must therefore follow +# the reexport through the sibling home unit, exactly as an ordinary import +# does. A home-unit search that ignores reexported-modules fails with +# "Could not load module 'MyPlugin' ... hidden package". +# +# -fbyte-code-and-object-code -fprefer-byte-code makes the plugin load as +# byte-code from its (interpreted) home unit, mirroring how a multiple-home-unit +# session is driven by 'cabal repl --enable-multi-repl' and HLS. +test('multipleHomeUnits_plugin02', + [req_plugins, extra_files(['p/', 'q/', 'r/', 'pluginunit', 'reexportunit', 'appunit'])], + multiunit_compile, + [['pluginunit', 'reexportunit', 'appunit'], + '-v0 -fbyte-code-and-object-code -fprefer-byte-code']) ===================================== testsuite/tests/driver/multipleHomeUnits/plugin02/appunit ===================================== @@ -0,0 +1 @@ +-working-dir q App -this-unit-id app-0 -this-package-name app -package-id reexport-0 ===================================== testsuite/tests/driver/multipleHomeUnits/plugin02/p/MyPlugin.hs ===================================== @@ -0,0 +1,8 @@ +module MyPlugin (plugin) where + +import GHC.Plugins + +-- A no-op plugin: it makes no changes to the program but, to run at all, it +-- must be found and loaded by the consumer module's compilation. +plugin :: Plugin +plugin = defaultPlugin { pluginRecompile = purePlugin } ===================================== testsuite/tests/driver/multipleHomeUnits/plugin02/pluginunit ===================================== @@ -0,0 +1 @@ +-working-dir p MyPlugin -this-unit-id plugin-0 -this-package-name plugin -package ghc ===================================== testsuite/tests/driver/multipleHomeUnits/plugin02/q/App.hs ===================================== @@ -0,0 +1,9 @@ +{-# OPTIONS_GHC -fplugin=MyPlugin #-} +module App where + +-- The plugin 'MyPlugin' lives in home unit plugin-0, but this unit (app-0) +-- depends only on reexport-0, which *reexports* MyPlugin (it does not contain +-- MyPlugin itself). Resolving -fplugin must therefore follow the reexport into +-- the sibling home unit, exactly as an ordinary import does. +app :: () +app = () ===================================== testsuite/tests/driver/multipleHomeUnits/plugin02/r/RexLib.hs ===================================== @@ -0,0 +1,8 @@ +module RexLib where + +-- Home unit reexport-0 re-exports MyPlugin (from plugin-0) via the +-- -reexported-module flag; see the 'reexportunit' arguments. This module exists +-- only to make reexport-0 a non-empty home unit, mirroring a real library +-- package that reexports a module from one of its dependencies. +rexLib :: () +rexLib = () ===================================== testsuite/tests/driver/multipleHomeUnits/plugin02/reexportunit ===================================== @@ -0,0 +1 @@ +-working-dir r RexLib -this-unit-id reexport-0 -this-package-name reexport -package-id plugin-0 -reexported-module MyPlugin View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/a3fa10e0c93a58f46815c4fab7522f4… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/a3fa10e0c93a58f46815c4fab7522f4… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] Fix two issues in the documentation of pipeline interruption
by Marge Bot (＠marge-bot) 17 Jun '26

17 Jun '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: f6d30767 by Wolfgang Jeltsch at 2026-06-16T15:32:34-04:00 Fix two issues in the documentation of pipeline interruption One issue is a typo (“interreuptible”), the other one the lack of an end of a sentence, which has been reconstructed from the message of 633bbc1fd4762a2bb73ba1c5b9e0c279f1dd3c40, the commit that introduced said documentation. - - - - - 1 changed file: - .gitlab-ci.yml Changes: ===================================== .gitlab-ci.yml ===================================== @@ -194,8 +194,9 @@ workflow: # https://gitlab.com/gitlab-org/gitlab/-/issues/32837) This leads to the # hack in this MR where by default all jobs are `interruptible: True`, but # for pipelines we definitely want to run, there is a dummy job which -# happens first, which is `interreuptible: False`. This has the effect of -# dirtying the whole pipeline and +# happens first, which is `interruptible: False`. This has the effect of +# dirtying the whole pipeline and preventing another push to master from +# cancelling it. # # For now, this patch solves the immediate problem of making sure nightly # jobs are not cancelled. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f6d3076790dc4306d06080f4c42a8c4… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f6d3076790dc4306d06080f4c42a8c4… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/az/ttg-hscondetails
by Alan Zimmerman (＠alanz) 17 Jun '26

17 Jun '26

Alan Zimmerman pushed new branch wip/az/ttg-hscondetails at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/az/ttg-hscondetails You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/az/exactprint-annotation-rationalisation] 5 commits: EPA: Harmonise HsQual/HsQualTy TTG extension annotations
by Alan Zimmerman (＠alanz) 17 Jun '26

17 Jun '26

Alan Zimmerman pushed to branch wip/az/exactprint-annotation-rationalisation at Glasgow Haskell Compiler / GHC Commits: d034595f by Alan Zimmerman at 2026-06-16T18:12:33+01:00 EPA: Harmonise HsQual/HsQualTy TTG extension annotations - - - - - 6444ba68 by Alan Zimmerman at 2026-06-16T18:12:33+01:00 EPA Remove LocatedLC / LocatedLS LocatedLC/LocatedLS were unused - - - - - d21dc757 by Alan Zimmerman at 2026-06-16T18:33:42+01:00 EPA: Remove LocatedLW from LStmtLR - - - - - a73050b5 by Alan Zimmerman at 2026-06-16T18:33:42+01:00 EPA: Remove LocatedLW from MatchGroup This is the last usage of LocatedLW / SrcSpanAnnLW - - - - - 79c8e7d0 by Alan Zimmerman at 2026-06-16T18:33:42+01:00 EPA: Move the 'where' annotation for PatSynBind This allows us to move it out of the MatchGroup exact print annotation too - - - - - 38 changed files: - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/Dump.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Annotation.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Parser/Types.hs - compiler/GHC/Rename/Bind.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Rename/Utils.hs - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/Arrow.hs - compiler/GHC/Tc/Gen/Do.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Match.hs - compiler/GHC/Tc/TyCl/PatSyn.hs - compiler/GHC/ThToHs.hs - compiler/Language/Haskell/Syntax/Expr.hs - testsuite/tests/ghc-api/T25121_status.stdout - testsuite/tests/ghc-api/exactprint/T22919.stderr - testsuite/tests/ghc-api/exactprint/ZeroWidthSemi.stderr - testsuite/tests/module/mod185.stderr - testsuite/tests/parser/should_compile/DumpParsedAst.stderr - testsuite/tests/parser/should_compile/DumpParsedAstComments.stderr - testsuite/tests/parser/should_compile/DumpRenamedAst.stderr - testsuite/tests/parser/should_compile/DumpSemis.stderr - testsuite/tests/parser/should_compile/DumpTypecheckedAst.stderr - testsuite/tests/parser/should_compile/KindSigs.stderr - testsuite/tests/parser/should_compile/T15279.stderr - testsuite/tests/parser/should_compile/T20718.stderr - testsuite/tests/parser/should_compile/T20846.stderr - testsuite/tests/parser/should_compile/all.T - testsuite/tests/printer/Test20297.stdout - testsuite/tests/printer/Test24533.stdout - utils/check-exact/ExactPrint.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/01db143ebe9d4a1a53f18f86fc1e90… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/01db143ebe9d4a1a53f18f86fc1e90… You're receiving this email because of your account on gitlab.haskell.org.

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