Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC

Commits:

• 987e5532
  by Rodrigo Mesquita at 2026-07-07T22:27:01-04:00

  ttg: Using ShortText over FastString in the AST
  
  To make the AST independent of GHC, this commit replaces usages of
  `FastString` with `HText` in the AST, killing the last edge from
  Language.Haskell.* to GHC.* modules.
  
  Even though we /do/ want to use FastStrings in general -- critically in
  Names or Ids -- there is no particular reason for the FastStrings that
  occur in the AST proper to be FastStrings. Strings in the AST are
  typically unique and don't benefit particularly from being interned
  FastStrings with Uniques for fast comparison.
  
  `HText` is a type synonym for `ShortText` which uses GHC's Modified
  UTF-8 encoding exclusively.
  
  Modified UTF-8 must be used to represent the Haskell AST because the
  Haskell Report allows surrogate code points. `Data.Text.Text` functions
  use Standard UTF-8 which replace surrogates with a placeholder value,
  thus `Data.Text.Text` is unsuitable for AST strings. See the
  `Language.Haskell.Syntax.Text` module header for more details.
  
  Final progress towards #21592
  
  Closes #21628
  

• 9f0ba364
  by Simon Peyton Jones at 2026-07-07T22:27:07-04:00

  Update equality-type documenation in GHC.Builtin.Types.Prim
  
  Fix #27466
  

• 295fcb33
  by Simon Peyton Jones at 2026-07-07T22:27:07-04:00

  Honour -dsuppress-coercions in GHC.Core.TyCo.pprCo
  
  Fixes #27467
  

• d990626e
  by Facundo Domínguez at 2026-07-07T22:27:11-04:00

  Add item to MR checklist asking to squash fixup commits after approval
  
  The checklist has an item that reads
  
      All commits are either individually buildable or squashed.
  
  This item could be checked immediately after sending the merge request
  though. If reviewers ask for amends later on, and the author amends
  the merge request, there was no item that would remind the contributors
  to squash the fixup commits before landing.
  
  This commit adds a new item
  
      After all approvals and before landing: all fixup commits are squashed with their originating commits.
  
  which should be harder to mark as done before approvals have been given.
  

107 changed files:

• .gitlab/merge_request_templates/Default.md
• + changelog.d/T21628
• compiler/GHC/Builtin/Types/Prim.hs
• compiler/GHC/Builtin/Utils.hs
• compiler/GHC/Cmm/CLabel.hs
• compiler/GHC/Core/Ppr.hs
• compiler/GHC/Core/TyCo/Ppr.hs
• compiler/GHC/Core/TyCo/Rep.hs
• compiler/GHC/Core/TyCon.hs
• compiler/GHC/Data/FastString.hs
• compiler/GHC/Data/StringBuffer.hs
• compiler/GHC/Driver/Errors/Ppr.hs
• compiler/GHC/Driver/Session.hs
• compiler/GHC/Hs/Decls.hs
• compiler/GHC/Hs/Dump.hs
• compiler/GHC/Hs/Expr.hs
• compiler/GHC/Hs/Lit.hs
• compiler/GHC/Hs/Type.hs
• compiler/GHC/Hs/Utils.hs
• compiler/GHC/HsToCore.hs
• compiler/GHC/HsToCore/Errors/Types.hs
• compiler/GHC/HsToCore/Expr.hs
• compiler/GHC/HsToCore/Foreign/C.hs
• compiler/GHC/HsToCore/Foreign/JavaScript.hs
• compiler/GHC/HsToCore/Foreign/Wasm.hs
• compiler/GHC/HsToCore/Match.hs
• compiler/GHC/HsToCore/Match/Literal.hs
• compiler/GHC/HsToCore/Pmc/Desugar.hs
• compiler/GHC/HsToCore/Pmc/Solver/Types.hs
• compiler/GHC/HsToCore/Quote.hs
• compiler/GHC/Iface/Syntax.hs
• compiler/GHC/Parser.y
• compiler/GHC/Parser/Errors/Ppr.hs
• compiler/GHC/Parser/HaddockLex.x
• compiler/GHC/Parser/Lexer.x
• compiler/GHC/Parser/PostProcess.hs
• compiler/GHC/Rename/Bind.hs
• compiler/GHC/Rename/Env.hs
• compiler/GHC/Rename/HsType.hs
• compiler/GHC/Rename/Module.hs
• compiler/GHC/Rename/Splice.hs
• compiler/GHC/Rename/Utils.hs
• compiler/GHC/StgToByteCode.hs
• compiler/GHC/StgToCmm/Foreign.hs
• compiler/GHC/StgToCmm/Prim.hs
• compiler/GHC/StgToJS/FFI.hs
• compiler/GHC/Tc/Deriv/Generate.hs
• compiler/GHC/Tc/Deriv/Generics.hs
• compiler/GHC/Tc/Errors.hs
• compiler/GHC/Tc/Errors/Ppr.hs
• compiler/GHC/Tc/Gen/Bind.hs
• compiler/GHC/Tc/Gen/Expr.hs
• compiler/GHC/Tc/Gen/HsType.hs
• compiler/GHC/Tc/Gen/Pat.hs
• compiler/GHC/Tc/Gen/Sig.hs
• compiler/GHC/Tc/Gen/Splice.hs
• compiler/GHC/Tc/Instance/Class.hs
• compiler/GHC/Tc/Solver/Dict.hs
• compiler/GHC/Tc/TyCl.hs
• compiler/GHC/Tc/TyCl/Utils.hs
• compiler/GHC/Tc/Types/Origin.hs
• compiler/GHC/Tc/Validity.hs
• compiler/GHC/ThToHs.hs
• compiler/GHC/Types/Basic.hs
• compiler/GHC/Types/Error.hs
• compiler/GHC/Types/FieldLabel.hs
• compiler/GHC/Types/ForeignCall.hs
• compiler/GHC/Types/Literal.hs
• compiler/GHC/Unit/Module/Warnings.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/Foreign.hs
• compiler/Language/Haskell/Syntax/Expr.hs
• compiler/Language/Haskell/Syntax/Lit.hs
• compiler/Language/Haskell/Syntax/Module/Name.hs
• + compiler/Language/Haskell/Syntax/Text.hs
• compiler/Language/Haskell/Syntax/Type.hs
• compiler/ghc.cabal.in
• libraries/ghc-boot/GHC/Data/ShortText.hs
• testsuite/tests/codeGen/should_compile/T25177.stderr
• testsuite/tests/count-deps/CountDepsAst.stdout
• testsuite/tests/count-deps/CountDepsParser.stdout
• testsuite/tests/ghc-api/annotations-literals/parsed.hs
• testsuite/tests/numeric/should_compile/T15547.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/DumpTypecheckedAst.stderr
• + testsuite/tests/parser/should_run/StringStartsWithNull.hs
• + testsuite/tests/parser/should_run/StringStartsWithNull.stdout
• testsuite/tests/parser/should_run/all.T
• testsuite/tests/perf/compiler/hard_hole_fits.stderr
• testsuite/tests/simplCore/should_compile/DataToTagFamilyScrut.stderr
• testsuite/tests/simplCore/should_compile/T14978.stdout
• testsuite/tests/simplCore/should_compile/T18013.stderr
• testsuite/tests/simplCore/should_compile/T24229a.stderr
• testsuite/tests/simplCore/should_compile/T24229b.stderr
• utils/check-exact/ExactPrint.hs
• utils/check-exact/check-exact.cabal
• utils/haddock/haddock-api/haddock-api.cabal
• utils/haddock/haddock-api/src/Haddock/Backends/Hyperlinker/Parser.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/Interface/Create.hs

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