Bodigrim pushed to branch wip/warning-for-last-and-init at Glasgow Haskell Compiler / GHC

Commits:

• 94b62aa7
  by Simon Peyton Jones at 2025-09-08T03:37:14-04:00

  Refactor ForAllCo
  
  This is a pure refactor, addressing #26389.
  
  It arranges that the kind coercion in a ForAllCo is a MCoercion, rather
  than a plain Coercion, thus removing redundancy in the common case.
  See (FC8) in Note [ForAllCo]
  
  It's a nice cleanup.
  

• 624afa4a
  by sheaf at 2025-09-08T03:38:05-04:00

  Use tcMkScaledFunTys in matchExpectedFunTys
  
  We should use tcMkScaledFunTys rather than mkScaledFunTys in
  GHC.Tc.Utils.Unify.matchExpectedFunTys, as the latter crashes
  when the kind of the result type is a bare metavariable.
  We know the result is always Type-like, so we don't need scaledFunTys
  to try to rediscover that from the kind.
  
  Fixes #26277
  

• 0975d2b6
  by sheaf at 2025-09-08T03:38:54-04:00

  Revert "Remove hptAllFamInstances usage during upsweep"
  
  This reverts commit 3bf6720eff5e86e673568e756161e6d6150eb440.
  

• 0cf34176
  by soulomoon at 2025-09-08T03:38:54-04:00

  Family consistency checks: add test for #26154
  
  This commit adds the test T26154, to make sure that GHC doesn't crash
  when performing type family consistency checks. This test case
  was extracted from Agda.
  
  Fixes #26154
  

• 846d48a2
  by Mike Pilgrem at 2025-09-08T22:55:43+01:00

  Re CLC issue 292 Warn GHC.Internal.List.{init,last} are partial
  
  Also corrects the warning for `tail` to refer to `Data.List.uncons` (like the existing warning for `head`).
  
  In module `Settings.Warnings`, applies `-Wno-x-partial` to the `filepath`, and `parsec` packages (outside GHC's repository).
  
  Also bumps submodules.
  

60 changed files:

• compiler/GHC/Core/Coercion.hs
• compiler/GHC/Core/Coercion.hs-boot
• compiler/GHC/Core/Coercion/Opt.hs
• compiler/GHC/Core/Lint.hs
• compiler/GHC/Core/Opt/Arity.hs
• compiler/GHC/Core/Reduction.hs
• compiler/GHC/Core/TyCo/FVs.hs
• compiler/GHC/Core/TyCo/Rep.hs
• compiler/GHC/Core/TyCo/Subst.hs
• compiler/GHC/Core/TyCo/Tidy.hs
• compiler/GHC/Core/Type.hs
• compiler/GHC/Core/Unify.hs
• compiler/GHC/Core/Utils.hs
• compiler/GHC/CoreToIface.hs
• compiler/GHC/Driver/Env.hs
• compiler/GHC/Driver/Session/Units.hs
• compiler/GHC/Iface/Rename.hs
• compiler/GHC/Iface/Syntax.hs
• compiler/GHC/Iface/Type.hs
• compiler/GHC/IfaceToCore.hs
• compiler/GHC/Prelude/Basic.hs
• compiler/GHC/Tc/Instance/Family.hs
• compiler/GHC/Tc/Module.hs
• compiler/GHC/Tc/TyCl/Utils.hs
• compiler/GHC/Tc/Utils/TcMType.hs
• compiler/GHC/Tc/Utils/TcType.hs
• compiler/GHC/Tc/Utils/Unify.hs
• compiler/GHC/Types/Id/Make.hs
• compiler/GHC/Unit/Home/Graph.hs
• compiler/GHC/Unit/Home/PackageTable.hs
• ghc/GHCi/UI.hs
• ghc/Main.hs
• hadrian/src/Settings/Warnings.hs
• libraries/base/changelog.md
• libraries/ghc-boot-th/GHC/Boot/TH/Ppr.hs
• libraries/ghc-internal/src/GHC/Internal/Float.hs
• libraries/ghc-internal/src/GHC/Internal/List.hs
• libraries/ghc-internal/src/GHC/Internal/System/IO.hs
• libraries/ghc-internal/src/GHC/Internal/TH/Syntax.hs
• libraries/template-haskell/vendored-filepath/System/FilePath/Posix.hs
• libraries/template-haskell/vendored-filepath/System/FilePath/Windows.hs
• testsuite/tests/driver/j-space/jspace.hs
• testsuite/tests/rts/KeepCafsBase.hs
• testsuite/tests/simplCore/should_compile/OpaqueNoCastWW.stderr
• + testsuite/tests/typecheck/should_compile/T26154.hs
• + testsuite/tests/typecheck/should_compile/T26154_A.hs
• + testsuite/tests/typecheck/should_compile/T26154_B.hs
• + testsuite/tests/typecheck/should_compile/T26154_B.hs-boot
• + testsuite/tests/typecheck/should_compile/T26154_Other.hs
• + testsuite/tests/typecheck/should_compile/T26277.hs
• testsuite/tests/typecheck/should_compile/all.T
• utils/check-exact/Main.hs
• utils/check-exact/Transform.hs
• utils/check-exact/Utils.hs
• utils/ghc-pkg/Main.hs
• utils/ghc-toolchain/src/GHC/Toolchain/CheckArm.hs
• utils/haddock/haddock-api/src/Haddock/Backends/Xhtml.hs
• utils/haddock/haddock-library/src/Documentation/Haddock/Parser.hs
• utils/hpc
• utils/hsc2hs

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