[Git][ghc/ghc][wip/teo/allow-newer-ghc-paths] 12 commits: Visible forall in GADTs (#25127)

Teo Camarasu pushed to branch wip/teo/allow-newer-ghc-paths at Glasgow Haskell Compiler / GHC Commits: fbc0b92a by Vladislav Zavialov at 2025-06-22T04:25:16+03:00 Visible forall in GADTs (#25127) Add support for visible dependent quantification `forall a -> t` in types of data constructors, e.g. data KindVal a where K :: forall k. forall (a::k) -> -- now allowed! k -> KindVal a For details, see docs/users_guide/exts/required_type_arguments.rst, which has gained a new subsection. DataCon in compiler/GHC/Core/DataCon.hs --------------------------------------- The main change in this patch is that DataCon, the Core representation of a data constructor, now uses a different type to store user-written type variable binders: - dcUserTyVarBinders :: [InvisTVBinder] + dcUserTyVarBinders :: [TyVarBinder] where type TyVarBinder = VarBndr TyVar ForAllTyFlag type InvisTVBinder = VarBndr TyVar Specificity and data Specificity = InferredSpec | SpecifiedSpec data ForAllTyFlag = Invisible Specificity | Required This change necessitates some boring, mechanical changes scattered throughout the diff: ... is now used in place of ... -----------------+--------------- TyVarBinder | InvisTVBinder IfaceForAllBndr | IfaceForAllSpecBndr Specified | SpecifiedSpec Inferred | InferredSpec mkForAllTys | mkInvisForAllTys additionally, tyVarSpecToBinders -- added or removed calls ifaceForAllSpecToBndrs -- removed calls Visibility casts in mkDataConRep -------------------------------- Type abstractions in Core (/\a. e) always have type (forall a. t) because coreTyLamForAllTyFlag = Specified. This is also true of data constructor workers. So we may be faced with the following: data con worker: (forall a. blah) data con wrapper: (forall a -> blah) In this case the wrapper must use a visibility cast (e |> ForAllCo ...) with appropriately set fco_vis{L,R}. Relevant functions: mkDataConRep in compiler/GHC/Types/Id/Make.hs dataConUserTyVarBindersNeedWrapper in compiler/GHC/Core/DataCon.hs mkForAllVisCos in compiler/GHC/Core/Coercion.hs mkCoreTyLams in compiler/GHC/Core/Make.hs mkWpForAllCast in compiler/GHC/Tc/Types/Evidence.hs More specifically: - dataConUserTyVarBindersNeedWrapper has been updated to answer "yes" if there are visible foralls in the type of the data constructor. - mkDataConRep now uses mkCoreTyLams to generate the big lambda abstractions (/\a b c. e) in the data con wrapper. - mkCoreTyLams is a variant of mkCoreLams that applies visibility casts as needed. It similar in purpose to the pre-existing mkWpForAllCast, so the common bits have been factored out into mkForAllVisCos. ConDecl in compiler/Language/Haskell/Syntax/Decls.hs ---------------------------------------------------- The surface syntax representation of a data constructor declaration is ConDecl. In accordance with the proposal, only GADT syntax is extended with support for visible forall, so we are interested in ConDeclGADT. ConDeclGADT's field con_bndrs has been renamed to con_outer_bndrs and is now accompanied by con_inner_bndrs: con_outer_bndrs :: XRec pass (HsOuterSigTyVarBndrs pass) con_inner_bndrs :: [HsForAllTelescope pass] Visible foralls always end up in con_inner_bndrs. The outer binders are stored and processed separately to support implicit quantification and the forall-or-nothing rule, a design established by HsSigType. A side effect of this change is that even in absence of visible foralls, GHC now permits multiple invisible foralls, e.g. data T a where { MkT :: forall a b. forall c d. ... -> T a } But of course, this is done in service of making at least some of these foralls visible. The entire compiler front-end has been updated to deal with con_inner_bndrs. See the following modified or added functions: Parser: mkGadtDecl in compiler/GHC/Parser/PostProcess.hs splitLHsGadtTy in compiler/GHC/Hs/Type.hs Pretty-printer: pprConDecl in compiler/GHC/Hs/Decls.hs pprHsForAllTelescope in compiler/GHC/Hs/Type.hs Renamer: rnConDecl in compiler/GHC/Rename/Module.hs bindHsForAllTelescopes in compiler/GHC/Rename/HsType.hs extractHsForAllTelescopes in compiler/GHC/Rename/HsType.hs Type checker: tcConDecl in compiler/GHC/Tc/TyCl.hs tcGadtConTyVarBndrs in compiler/GHC/Tc/Gen/HsType.hs Template Haskell ---------------- The TH AST is left unchanged for the moment to avoid breakage. An attempt to quote or reify a data constructor declaration with visible forall in its type will result an error: data ThRejectionReason -- in GHC/HsToCore/Errors/Types.hs = ... | ThDataConVisibleForall -- new error constructor However, as noted in the previous section, GHC now permits multiple invisible foralls, and TH was updated accordingly. Updated code: repC in compiler/GHC/HsToCore/Quote.hs reifyDataCon in compiler/GHC/Tc/Gen/Splice.hs ppr @Con in libraries/ghc-boot-th/GHC/Boot/TH/Ppr.hs Pattern matching ---------------- Everything described above concerns data constructor declarations, but what about their use sites? Now it is trickier to type check a pattern match fn(Con a b c)=... because we can no longer assume that a,b,c are all value arguments. Indeed, some or all of them may very well turn out to be required type arguments. To that end, see the changes to: tcDataConPat in compiler/GHC/Tc/Gen/Pat.hs splitConTyArgs in compiler/GHC/Tc/Gen/Pat.hs and the new helpers split_con_ty_args, zip_pats_bndrs. This is also the reason the TcRnTooManyTyArgsInConPattern error constructor has been removed. The new code emits TcRnArityMismatch or TcRnIllegalInvisibleTypePattern. Summary ------- DataCon, ConDecl, as well as all related functions have been updated to support required type arguments in data constructors. Test cases: HieGadtConSigs GadtConSigs_th_dump1 GadtConSigs_th_pprint1 T25127_data T25127_data_inst T25127_infix T25127_newtype T25127_fail_th_quote T25127_fail_arity TyAppPat_Tricky Co-authored-by: mniip - - - - - ae003a3a by Teo Camarasu at 2025-06-23T05:21:48-04:00 linters: lint-whitespace: bump upper-bound for containers The version of containers was bumped in https://gitlab.haskell.org/ghc/ghc/-/merge_requests/13989 - - - - - 0fb37893 by Matthew Pickering at 2025-06-23T13:55:10-04:00 Move ModuleGraph into UnitEnv The ModuleGraph is a piece of information associated with the ExternalPackageState and HomeUnitGraph. Therefore we should store it inside the HomeUnitEnv. - - - - - 3bf6720e by soulomoon at 2025-06-23T13:55:52-04:00 Remove hptAllFamInstances usage during upsweep Fixes #26118 This change eliminates the use of hptAllFamInstances during the upsweep phase, as it could access non-below modules from the home package table. The following updates were made: * Updated checkFamInstConsistency to accept an explicit ModuleEnv FamInstEnv parameter and removed the call to hptAllFamInstances. * Adjusted hugInstancesBelow so we can construct ModuleEnv FamInstEnv from its result, * hptAllFamInstances and allFamInstances functions are removed. - - - - - 83ee7b78 by Ben Gamari at 2025-06-24T05:02:07-04:00 configure: Don't force value of OTOOL, etc. if not present Previously if `otool` and `install_name_tool` were not present they would be overridden by `fp_settings.m4`. This logic was introduced in 4ff93292243888545da452ea4d4c1987f2343591 without explanation. - - - - - 9329c9e1 by Ben Gamari at 2025-06-24T05:02:07-04:00 ghc-toolchain: Add support for otool, install_name_tool Fixes part of ghc#23675. - - - - - 25f5c998 by Ben Gamari at 2025-06-24T05:02:08-04:00 ghc-toolchain: Add support for llc, opt, llvm-as Fixes #23675. - - - - - 51d150dd by Rodrigo Mesquita at 2025-06-24T05:02:08-04:00 hadrian: Use settings-use-distro-mingw directly The type `ToolchainSetting` only made sense when we had more settings to fetch from the system config file. Even then "settings-use-distro-mingw" is arguably not a toolchain setting. With the fix for #23675, all toolchain tools were moved to the `ghc-toolchain` `Toolchain` format. Therefore, we can inline `settings-use-distro-mingw` accesses and delete `ToolchainSetting`. - - - - - dcf68a83 by Rodrigo Mesquita at 2025-06-24T05:02:08-04:00 configure: Check LlvmTarget exists for LlvmAsFlags If LlvmTarget was empty, LlvmAsFlags would be just "--target=". If it is empty now, simply keep LlvmAsFlags empty. ghc-toolchain already does this right. This fix makes the two configurations match up. - - - - - 580a3353 by Ben Gamari at 2025-06-24T05:02:51-04:00 rts/linker/LoadArchive: Use bool Improve type precision by using `bool` instead of `int` and `StgBool`. - - - - - 76d1041d by Ben Gamari at 2025-06-24T05:02:51-04:00 rts/linker/LoadArchive: Don't rely on file extensions for identification Previously archive members would be identified via their file extension, as described in #13103. We now instead use a more principled approach, relying on the magic number in the member's header. As well, we refactor treatment of archive format detection to improve code clarity and error handling. Closes #13103. - - - - - 878c3888 by Teo Camarasu at 2025-06-24T13:46:32+00:00 cabal.project-reinstall: allow newer ghc-paths:Cabal This upper bound will be wrong whenever we are using a development version of Cabal in-tree, so let's just add an allow-newer here - - - - - 112 changed files: - cabal.project-reinstall - compiler/GHC.hs - compiler/GHC/Builtin/Types.hs - compiler/GHC/Core/Coercion.hs - compiler/GHC/Core/ConLike.hs - compiler/GHC/Core/DataCon.hs - compiler/GHC/Core/DataCon.hs-boot - compiler/GHC/Core/Make.hs - compiler/GHC/Core/Opt/Pipeline.hs - compiler/GHC/Core/PatSyn.hs - compiler/GHC/Core/TyCo/Ppr.hs - compiler/GHC/Core/TyCo/Rep.hs - compiler/GHC/Driver/Backpack.hs - compiler/GHC/Driver/Env.hs - compiler/GHC/Driver/Env/Types.hs - compiler/GHC/Driver/Main.hs - compiler/GHC/Driver/Make.hs - compiler/GHC/Driver/Pipeline/Execute.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Pat.hs - compiler/GHC/Hs/Type.hs - compiler/GHC/HsToCore/Errors/Ppr.hs - compiler/GHC/HsToCore/Errors/Types.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/Iface/Decl.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Load.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Parser/PostProcess/Haddock.hs - compiler/GHC/Rename/HsType.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.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/Instance/Family.hs - compiler/GHC/Tc/Module.hs - compiler/GHC/Tc/TyCl.hs - compiler/GHC/Tc/TyCl/Build.hs - compiler/GHC/Tc/TyCl/Utils.hs - compiler/GHC/Tc/Types/Evidence.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Types/Id/Make.hs - compiler/GHC/Types/Var.hs-boot - compiler/GHC/Unit/Env.hs - compiler/GHC/Unit/Home/Graph.hs - compiler/GHC/Unit/Home/PackageTable.hs - compiler/Language/Haskell/Syntax/Decls.hs - compiler/Language/Haskell/Syntax/Pat.hs - distrib/configure.ac.in - docs/users_guide/9.14.1-notes.rst - docs/users_guide/exts/gadt_syntax.rst - docs/users_guide/exts/required_type_arguments.rst - ghc/GHCi/UI.hs - hadrian/cfg/default.host.target.in - hadrian/cfg/default.target.in - hadrian/cfg/system.config.in - hadrian/src/Builder.hs - hadrian/src/Oracles/Setting.hs - hadrian/src/Rules/Generate.hs - hadrian/src/Settings/Builders/RunTest.hs - libraries/ghc-boot-th/GHC/Boot/TH/Ppr.hs - linters/lint-whitespace/lint-whitespace.cabal - m4/fp_settings.m4 - m4/ghc_toolchain.m4 - m4/prep_target_file.m4 - rts/linker/LoadArchive.c - testsuite/tests/dependent/should_fail/T16326_Fail6.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T17544.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T17544_kw.stderr - + testsuite/tests/hiefile/should_run/HieGadtConSigs.hs - + testsuite/tests/hiefile/should_run/HieGadtConSigs.stdout - testsuite/tests/hiefile/should_run/all.T - testsuite/tests/parser/should_compile/DumpParsedAst.stderr - testsuite/tests/parser/should_compile/DumpRenamedAst.stderr - testsuite/tests/parser/should_compile/T15323.stderr - testsuite/tests/printer/T18791.stderr - + testsuite/tests/th/GadtConSigs_th_dump1.hs - + testsuite/tests/th/GadtConSigs_th_dump1.stderr - + testsuite/tests/th/GadtConSigs_th_pprint1.hs - + testsuite/tests/th/GadtConSigs_th_pprint1.stderr - testsuite/tests/th/T20868.stdout - testsuite/tests/th/all.T - testsuite/tests/typecheck/should_compile/T23739a.hs - + testsuite/tests/typecheck/should_compile/TyAppPat_Tricky.hs - testsuite/tests/typecheck/should_compile/all.T - testsuite/tests/typecheck/should_fail/T20443b.stderr - testsuite/tests/typecheck/should_fail/TyAppPat_TooMany.stderr - + testsuite/tests/vdq-rta/should_compile/T25127_data.hs - + testsuite/tests/vdq-rta/should_compile/T25127_data_inst.hs - + testsuite/tests/vdq-rta/should_compile/T25127_infix.hs - + testsuite/tests/vdq-rta/should_compile/T25127_newtype.hs - testsuite/tests/vdq-rta/should_compile/all.T - testsuite/tests/vdq-rta/should_fail/T24159_type_syntax_th_fail.script - + testsuite/tests/vdq-rta/should_fail/T25127_fail_arity.hs - + testsuite/tests/vdq-rta/should_fail/T25127_fail_arity.stderr - + testsuite/tests/vdq-rta/should_fail/T25127_fail_th_quote.hs - + testsuite/tests/vdq-rta/should_fail/T25127_fail_th_quote.stderr - testsuite/tests/vdq-rta/should_fail/all.T - utils/check-exact/ExactPrint.hs - utils/ghc-toolchain/exe/Main.hs - utils/ghc-toolchain/src/GHC/Toolchain/Target.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/Rename.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/bec4067da0a7a8a00cf26d468a87107... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/bec4067da0a7a8a00cf26d468a87107... You're receiving this email because of your account on gitlab.haskell.org.