Andreas Klebinger pushed to branch wip/andreask/build-opt at Glasgow Haskell Compiler / GHC

Commits:

• 74e4e745
  by Andreas Klebinger at 2026-04-20T20:04:26+00:00

  SOURCE-import HsInstances inside ghc.
  
  Fixes #27198 by SOURCE importing HsInstances unlocking
  more build paralleism.
  

• 2bfb4ced
  by Andreas Klebinger at 2026-04-20T20:04:48+00:00

  SOURCE import GHC.Types.Error in some places for build parallelism.
  
  Performance for these interfaces is not very relevant since it's only used for error handling.
  This means we can use SOURCE imports to shorten the critical build path
  by a non trivial amount.
  

• 0be2e78a
  by Andreas Klebinger at 2026-04-20T20:04:48+00:00

  Split GHC.Driver.Main.hs up into multiple components.
  
  This module was getting far too large to reason about, it split it
  into components that all are re-exported from GHC.Driver.Main
  
  I mostly did this for clarity but it also helps (slightly) with build
  times.
  

• b4b25892
  by Andreas Klebinger at 2026-04-20T20:04:48+00:00

  Add a few boot files and SOURCE import them to improve build parallelism.
  
  See the Note [hs-boot files as "header" files] for details.
  
  Modules with new SOURCE exports:
  
  * GHC.HsToCore (deSugar)
  * GHC.Tc.Deriv.hs-boot
  * GHC.Driver.Main.Compile/Passes
  

24 changed files:

• compiler/GHC/Core/Opt/Stats.hs
• compiler/GHC/Driver/Backpack.hs
• compiler/GHC/Driver/Env/Types.hs
• compiler/GHC/Driver/Errors/Types.hs
• compiler/GHC/Driver/Main.hs
• + compiler/GHC/Driver/Main/Compile.hs
• compiler/GHC/Driver/Main.hs-boot → compiler/GHC/Driver/Main/Compile.hs-boot
• + compiler/GHC/Driver/Main/Hsc.hs
• + compiler/GHC/Driver/Main/Interactive.hs
• + compiler/GHC/Driver/Main/Passes.hs
• + compiler/GHC/Driver/Main/Passes.hs-boot
• compiler/GHC/Driver/Session.hs
• compiler/GHC/Hs.hs
• compiler/GHC/Hs/Instances.hs
• + compiler/GHC/Hs/Instances.hs-boot
• + compiler/GHC/HsToCore.hs-boot
• compiler/GHC/Iface/Load.hs
• + compiler/GHC/Tc/Deriv.hs-boot
• compiler/GHC/Tc/TyCl.hs
• compiler/GHC/Tc/TyCl/Instance.hs
• compiler/GHC/Tc/TyCl/Instance.hs-boot
• compiler/GHC/Types/Error.hs
• compiler/GHC/Types/Error.hs-boot
• compiler/ghc.cabal.in

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