[Git][ghc/ghc][wip/T24464] 17 commits: Remove `GHC.Desugar` from `base`

Simon Peyton Jones pushed to branch wip/T24464 at Glasgow Haskell Compiler / GHC Commits: 607b287b by Wolfgang Jeltsch at 2026-01-28T15:41:53+02:00 Remove `GHC.Desugar` from `base` `GHC.Desugar` was deprecated and should have been removed in GHC 9.14. However, the removal was forgotten, although there was a code block that was intended to trigger a compilation error when the GHC version in use was 9.14 or later. This code sadly didn’t work, because the `__GLASGOW_HASKELL__` macro was misspelled as `__GLASGOW_HASKELL`. - - - - - e8f5a45d by sterni at 2026-01-29T04:19:18-05:00 users_guide: fix runtime error during build with Sphinx 9.1.0 Appears that pathto is stricter about what it accepts now. Tested Sphinx 8.2.3 and 9.1.0 on the ghc-9.10 branch. Resolves #26810. Co-authored-by: Martin Weinelt - - - - - ce2d62fb by Jessica Clarke at 2026-01-29T19:48:51-05:00 PPC NCG: Use libcall for 64-bit cmpxchg on 32-bit PowerPC There is no native instruction for this, and even if there were a register pair version we could use, the implementation here is assuming the values fit in a single register, and we end up only using / defining the low halves of the registers. Fixes: b4d39adbb5 ("PrimOps: Add CAS op for all int sizes") Fixes: #23969 - - - - - 43d97761 by Michael Karcher at 2026-01-29T19:49:43-05:00 NCG for PPC: add pattern for CmmRegOff to iselExpr64 Closes #26828 - - - - - aeeb4a20 by Matthew Pickering at 2026-01-30T11:42:47-05:00 determinism: Use deterministic map for Strings in TyLitMap When generating typeable evidence the types we need evidence for all cached in a TypeMap, the order terms are retrieved from a type map determines the order the bindings appear in the program. A TypeMap is quite diligent to use deterministic maps, apart from in the TyLitMap, which uses a UniqFM for storing strings, whose ordering depends on the Unique of the FastString. This can cause non-deterministic .hi and .o files. An unexpected side-effect is the error message but RecordDotSyntaxFail8 changing. I looked into this with Sam and this change caused the constraints to be solved in a different order which results in a slightly different error message. I have accepted the new test, since the output before was non-deterministic and the new output is consistent with the other messages in that file. Fixes #26846 - - - - - 9e4d70c2 by Andrew Lelechenko at 2026-01-30T11:43:29-05:00 Upgrade text submodule to 2.1.4 - - - - - 631fa5ae by Recursion Ninja at 2026-01-31T22:30:11+00:00 Decouple `L.S.H.Decls` from importing `GHC.Types.Basic` Data-types within `GHC.Types.Basic` which describe components of the AST are migrated to `Language.Haskell.Syntax.Basic`. Related function definitions are also moved. Types moved to L.H.S. because they are part of the AST: * TopLevelFlag * RuleName Types moved from L.H.S. to GHC.Hs. because they are not needed in the AST: * TyConFlavour * TypeOrData * NewOrData Migrated instances: * `Outputable` instances moved to in `GHC.Utils.Outputable` * `Binary` instance of `Boxity` moved to to `GHC.Utils.Binary` * Other `Binary` instances are orphans to be migrated later. The `OverlapMode` data-type is given a TTG extension point. The `OverlapFlag` data-type, which depends on `OverlapMode`, is updated to support `OverlapMode` with a GHC "pass" type paramerter. In order to avoid module import cycles, `OverlapMode` and `OverlapFlag` are migrated to new modules (no way around this). * Migrated `OverlapMode` to new module `Language.Haskell.Syntax.Overlap` * Migrated `OverlapFlag` to new module `GHC.Hs.Decls.Overlap` - - - - - 9769cc03 by Simon Hengel at 2026-02-01T04:21:03-05:00 Update the documentation for MultiWayIf (fixes #25376) (so that it matches the implementation) - - - - - 5fc9442a by Peter Trommler at 2026-02-01T04:21:44-05:00 hadrian: Fix dependency generation for assembler Assembler files allow # for comments unless in column 1. A modern cpp for C treats those a preprocessor directives. We tell gcc that a .S file is assembler with cpp and not C. Fixes #26819 - - - - - 269c4087 by Simon Peyton Jones at 2026-02-01T19:38:10-05:00 Include current phase in the range for rule/unfoldings This MR fixes a bad loop in the compiler: #26826. The fix is to add (WAR2) to Note [What is active in the RHS of a RULE or unfolding?] in GHC.Core.Opt.Simplify.Utils - - - - - ddf1434f by Vladislav Zavialov at 2026-02-01T19:38:52-05:00 Refactor: merge HsMultilineString into HsString (#26860) Before this patch, HsLit defined two separate constructors to represent single-line and multi-line strings: data HsLit x ... | HsString (XHsString x) FastString | HsMultilineString (XHsMultilineString x) FastString I found this to be an unnecessary complication and an obstacle to unifying HsLit with HsTyLit. Now we use HsString for both kinds of literals. One user-facing change here is `ppr (HsString st s)` behaving differently for single-line strings containing newlines: x = "first line \ \asdf\n\ \second line" Previously, the literal was fed to `ftext` with its newlines, producing an ill-formed SDoc. This issue is now addressed by using `split` for both single-line and multi-line strings: vcat $ map text $ split '\n' (unpackFS src) See the parser/should_fail/T26860ppr test. In addition (and unrelatedly to the main payload of this patch), drop the unused pmPprHsLit helper. - - - - - 2b4f463c by Simon Peyton Jones at 2026-02-02T17:32:32+00:00 Remove exprIsCheap from doFloatFromRhs See #26854 and Note [Float when expandable] This patch simplifies the code, by removing an extra unnecessary test. - - - - - 9db7f21f by Brandon Chinn at 2026-02-03T09:15:10-05:00 Refactor: make function patterns exhaustive Also added missing (==) logic for: * HsMultilineString * HsInt{8,16,32} * HsWord{8,16,32} - - - - - aa9c5e2c by Hécate Kleidukos at 2026-02-03T15:58:35-05:00 driver: Hide source paths at verbosity level 1 by default - - - - - c64cca1e by mangoiv at 2026-02-03T15:59:29-05:00 ExplicitLevelImports: check staging for types just like for values Previously, imported types were entirely exempted from staging checks as the implicit stage persistance assumed to be all imported types to be well staged. ExplicitLevelImports' change specification, however, does not do such an exemption. Thus we want to introduce such a check, just like we have for values. ExplicitLevelImports does not, however, talk about local names - from its perspective, we could theoretically keep treating locally introduced types specially - e.g. an ill-staged used in a quote would only emit a warning, not an error. To allow for a potential future migration away from such wrinkles as the staging check in notFound (see Note [Out of scope might be a staging error]) we consistently do the strict staging check that we also do for value if ExplicitLevelImports is on. Closes #26098 - - - - - 5f0dbeb6 by Simon Hengel at 2026-02-03T16:00:12-05:00 Use Haddock formatting in deprecation message of `initNameCache` - - - - - 3f9f6362 by Simon Peyton Jones at 2026-02-03T22:12:42+00:00 Simplify the treatment of static forms This MR implements GHC proposal 732: simplify static forms, https://github.com/ghc-proposals/ghc-proposals/pull/732 thereby addressing #26556. See `Note [Grand plan for static forms]` in GHC.Iface.Tidy.StaticPtrTable The main changes are: * There is a new, simple rule for (static e), namely that the free term variables of `e` must be bound at top level. The check is done in the `HsStatic` case of `GHC.Rename.Expr.rnExpr` * That in turn substantially simplifies the info that the typechecker carries around in its type environment. Hooray. * The desugarer emits static bindings to top level directly; see the `HsStatic` case of `dsExpr`. * There is no longer any special static-related magic in the FloatOut pass. And the main Simplifier pipeline no longer needs a special case to run FloatOut even with -O0. Hooray. All this forced an unexpected change to the pattern match checker. It recursively invokes the main Hs desugarer when it wants to take a look at a term to spot some special cases (notably constructor applications). We don't want to emit any nested (static e) bindings to top level a second time! Yikes. That forced a modest refactor in GHC.HsToCore.Pmc: * The `dsl_nablas` field of `DsLclEnv` now has a `NoPmc` case, which says "I'm desugaring just for pattern-match checking purposes". * When that flag is set we don't emit static binds. That in turn forces a cascade of refactoring, but the net effect is an improvement; less risk of duplicated (even exponential?) work. 10% metric decrease, on some architectures, of compile-time max-bytes-used on T15304. Metric Decrease: T15304 - - - - - 165 changed files: - compiler/GHC/CmmToAsm/PPC/CodeGen.hs - compiler/GHC/Core/InstEnv.hs - compiler/GHC/Core/Lint.hs - compiler/GHC/Core/Map/Type.hs - compiler/GHC/Core/Opt/OccurAnal.hs - compiler/GHC/Core/Opt/Pipeline.hs - compiler/GHC/Core/Opt/SetLevels.hs - compiler/GHC/Core/Opt/Simplify/Env.hs - compiler/GHC/Core/Opt/Simplify/Utils.hs - compiler/GHC/Core/Opt/WorkWrap.hs - compiler/GHC/CoreToStg/AddImplicitBinds.hs - compiler/GHC/Driver/Config/Core/Lint.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/Decls.hs - + compiler/GHC/Hs/Decls/Overlap.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Hs/Lit.hs - compiler/GHC/Hs/Syn/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/HsToCore/Errors/Types.hs - compiler/GHC/HsToCore/Expr.hs - compiler/GHC/HsToCore/GuardedRHSs.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Match/Literal.hs - compiler/GHC/HsToCore/Monad.hs - compiler/GHC/HsToCore/Pmc.hs - compiler/GHC/HsToCore/Pmc/Desugar.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/HsToCore/Ticks.hs - compiler/GHC/HsToCore/Types.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Iface/Tidy.hs - compiler/GHC/Iface/Tidy/StaticPtrTable.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/String.hs - compiler/GHC/Rename/Bind.hs - compiler/GHC/Rename/Env.hs - compiler/GHC/Rename/Expr.hs - compiler/GHC/Rename/HsType.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Rename/Names.hs - compiler/GHC/Rename/Splice.hs - compiler/GHC/Rename/Splice.hs-boot - compiler/GHC/Tc/Deriv.hs - compiler/GHC/Tc/Deriv/Utils.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/Bind.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/Gen/Sig.hs - compiler/GHC/Tc/Module.hs - compiler/GHC/Tc/Solver.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/TyCl/Instance.hs - compiler/GHC/Tc/TyCl/Utils.hs - compiler/GHC/Tc/Types.hs - compiler/GHC/Tc/Types/BasicTypes.hs - compiler/GHC/Tc/Types/Constraint.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Utils/Env.hs - compiler/GHC/Tc/Utils/Instantiate.hs - compiler/GHC/Tc/Utils/Monad.hs - − compiler/GHC/Tc/Utils/TcMType.hs-boot - compiler/GHC/Tc/Zonk/TcType.hs - compiler/GHC/Tc/Zonk/Type.hs - compiler/GHC/ThToHs.hs - compiler/GHC/Types/Basic.hs - compiler/GHC/Types/Id/Make.hs - compiler/GHC/Types/InlinePragma.hs - compiler/GHC/Types/Name.hs - compiler/GHC/Types/Name/Cache.hs - compiler/GHC/Unit/Types.hs - compiler/GHC/Utils/Binary.hs - compiler/GHC/Utils/Outputable.hs - compiler/Language/Haskell/Syntax/Basic.hs - compiler/Language/Haskell/Syntax/Decls.hs - + compiler/Language/Haskell/Syntax/Decls/Overlap.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/Lit.hs - compiler/ghc.cabal.in - docs/users_guide/9.16.1-notes.rst - docs/users_guide/exts/multiway_if.rst - docs/users_guide/rtd-theme/layout.html - hadrian/src/Builder.hs - hadrian/src/Rules/Compile.hs - hadrian/src/Settings/Builders/Cc.hs - hadrian/src/Settings/Builders/RunTest.hs - hadrian/src/Settings/Packages.hs - libraries/base/base.cabal.in - − libraries/base/src/GHC/Desugar.hs - libraries/text - testsuite/mk/test.mk - testsuite/tests/backpack/cabal/bkpcabal08/bkpcabal08.stdout - testsuite/tests/codeGen/should_run/CgStaticPointers.hs - testsuite/tests/codeGen/should_run/CgStaticPointersNoFullLazyness.hs - testsuite/tests/count-deps/CountDepsAst.stdout - testsuite/tests/count-deps/CountDepsParser.stdout - testsuite/tests/driver/T20030/test1/all.T - testsuite/tests/driver/T20030/test2/all.T - testsuite/tests/driver/T20030/test3/all.T - testsuite/tests/driver/T20030/test4/all.T - testsuite/tests/driver/T20030/test5/all.T - testsuite/tests/driver/T20030/test6/all.T - testsuite/tests/driver/T8526/T8526.script - testsuite/tests/driver/bytecode-object/Makefile - testsuite/tests/driver/bytecode-object/bytecode_object19.stdout - testsuite/tests/driver/dynamicToo/dynamicToo001/Makefile - testsuite/tests/driver/fat-iface/fat014.script - testsuite/tests/driver/implicit-dyn-too/Makefile - testsuite/tests/driver/multipleHomeUnits/all.T - testsuite/tests/driver/multipleHomeUnits/multipleHomeUnits_recomp_th.stdout - + testsuite/tests/ghc-api/TypeMapStringLiteral.hs - testsuite/tests/ghc-api/all.T - − testsuite/tests/ghci/linking/T11531.stderr - testsuite/tests/ghci/prog018/prog018.script - testsuite/tests/ghci/scripts/T13869.script - testsuite/tests/ghci/scripts/T13997.script - testsuite/tests/ghci/scripts/T17669.script - testsuite/tests/ghci/scripts/T18330.script - testsuite/tests/ghci/scripts/T18330.stdout - testsuite/tests/ghci/scripts/T1914.script - testsuite/tests/ghci/scripts/T20150.stdout - testsuite/tests/ghci/scripts/T20217.script - testsuite/tests/ghci/scripts/T6105.script - testsuite/tests/ghci/scripts/T8042.script - testsuite/tests/ghci/scripts/T8042recomp.script - testsuite/tests/ghci/should_run/Makefile - 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/interface-stability/base-exports.stdout-ws-32 - testsuite/tests/parser/should_compile/DumpRenamedAst.stderr - testsuite/tests/parser/should_compile/T14189.stderr - testsuite/tests/parser/should_fail/RecordDotSyntaxFail8.stderr - + testsuite/tests/parser/should_fail/T26860ppr.hs - + testsuite/tests/parser/should_fail/T26860ppr.stderr - testsuite/tests/parser/should_fail/all.T - testsuite/tests/rename/should_fail/RnStaticPointersFail01.stderr - testsuite/tests/rename/should_fail/RnStaticPointersFail03.stderr - testsuite/tests/rts/T13676.script - + testsuite/tests/simplCore/should_compile/T26826.hs - testsuite/tests/simplCore/should_compile/all.T - + testsuite/tests/th/T26098A_quote.hs - + testsuite/tests/th/T26098A_splice.hs - + testsuite/tests/th/T26098_local.hs - + testsuite/tests/th/T26098_local.stderr - + testsuite/tests/th/T26098_quote.hs - + testsuite/tests/th/T26098_quote.stderr - + testsuite/tests/th/T26098_splice.hs - + testsuite/tests/th/T26098_splice.stderr - testsuite/tests/th/all.T - testsuite/tests/warnings/should_fail/CaretDiagnostics1.stderr - utils/check-exact/ExactPrint.hs - utils/haddock/haddock-api/src/Haddock/Backends/Hoogle.hs - utils/haddock/haddock-api/src/Haddock/Convert.hs - utils/haddock/haddock-api/src/Haddock/Interface/Rename.hs - utils/haddock/haddock-api/src/Haddock/Types.hs The diff was not included because it is too large. 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