Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: db9c95ac by Wolfgang Jeltsch at 2026-09-24T15:51:34-04:00 Correct the documentation of `explicitUnits` Resolves #27787. - - - - - a6b642b6 by Simon Jakobi at 2026-09-24T15:51:35-04:00 Remove stale specHeader bullet from Note [Don't make fillers for constraint types] The Note said that Specialise.specHeader also calls mkAbsentFiller. abfc224a27c removed that call: the specialiser no longer drops dead arguments at all, see Note [Do not drop dead args from specialisations] in GHC.Core.Opt.Specialise. Assisted-by: Claude Fable 5.1 - - - - - 2 changed files: - compiler/GHC/Core/Opt/WorkWrap/Utils.hs - compiler/GHC/Unit/State.hs Changes: ===================================== compiler/GHC/Core/Opt/WorkWrap/Utils.hs ===================================== @@ -1367,13 +1367,8 @@ It's surprisingly subtle. application; see test `T27627f`. TL;DR: we play safe: we never make an absent filler for any /constraint-kinded/ type, -using `isPredTy` to decide. - - * `mkAbsentFiller` returns `Nothing` for any constraint type, so worker/wrapper - keeps the real argument. - - * `Specialise.specHeader` calls `mkAbsentFiller` too, so it likewise keeps the - dead dictionary argument rather than dropping it for a filler. +using `isPredTy` to decide: `mkAbsentFiller` returns `Nothing` for any constraint +type, so worker/wrapper keeps the real argument. Prior failed approaches ===================================== compiler/GHC/Unit/State.hs ===================================== @@ -369,10 +369,15 @@ data UnitState = UnitState { -- is always mentioned before the units it depends on. preloadUnits :: [UnitId], - -- | Units which we explicitly depend on (from a command line flag). - -- We'll use this to generate version macros and the unused packages warning. The - -- original flag which was used to bring the unit into scope is recorded for the - -- -Wunused-packages warning. + -- | The units that can be used by the respective home unit. Despite the + -- identifier, this does not just cover units that are enabled explicitly + -- using flags but also units from the package database that are enabled + -- implicitly in case @-hide-all-packages@ is absent. The former are paired + -- with 'Just' applied to the respective flags, the latter are paired with + -- 'Nothing'. + -- + -- This field is used for generating version macros and “unused packages” + -- warnings. explicitUnits :: [(Unit, Maybe PackageArg)], homeUnitDepends :: Set UnitId, @@ -907,7 +912,7 @@ mkUnitState logger unit_index cfg = do let pkgname_map = listToUFM [ (unitPackageName p, unitInstanceOf p) | p <- pkgs2 ] - -- The explicitUnits accurately reflects the set of units we have turned + -- The explicitUnits accurately reflects the set of units that are turned -- on; as such, it also is the only way one can come up with requirements. -- The requirement context is directly based off of this: we simply -- look for nested unit IDs that are directly fed holes: the requirements View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/f08bae90b4359fde91eb2493f9bd49d... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/f08bae90b4359fde91eb2493f9bd49d... 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