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Teo Camarasu pushed to branch wip/T26226 at Glasgow Haskell Compiler / GHC

Commits:

81fc5795

by Teo Camarasu at 2025-07-25T20:05:15+01:00

ghci: always enable the internal-interpreter flag

Building iserv requires the modules hidden behind the ghci
internal-interpreter flag.

This flag exists because these modules depend on parts of the
TemplateHaskell interface, and historically we couldn't distinguish
between the boot and the in-tree TH interface. This meant that these
modules could only be built in stage0 if we've ensured that the boot TH
interface matches the in-tree one.

This restriction no longer holds as of
https://gitlab.haskell.org/ghc/ghc/-/merge_requests/12306.

Removing this flag simplifies our logic, and is a step towards enabling
using TH in bootstrapping (https://gitlab.haskell.org/ghc/ghc/-/issues/24624).

3 changed files:

hadrian/src/Settings/Packages.hs
libraries/ghci/GHCi/Run.hs
libraries/ghci/ghci.cabal.in

Changes:

hadrian/src/Settings/Packages.hs

@@ -25,10 +25,6 @@ packageArgs = do
          -- See: https://gitlab.haskell.org/ghc/ghc/issues/16809.
          cross = flag CrossCompiling
 -        -- Check if the bootstrap compiler has the same version as the one we
 -        -- are building. This is used to build cross-compilers
 -        bootCross = (==) <$> ghcVersionStage (stage0InTree) <*> ghcVersionStage Stage1
+-
          compilerStageOption f = buildingCompilerStage' . f =<< expr flavour
      cursesIncludeDir <- getSetting CursesIncludeDir
@@ -128,39 +124,9 @@ packageArgs = do
          --------------------------------- ghci ---------------------------------
          , package ghci ? mconcat
 -          [
 -          -- The use case here is that we want to build @iserv-proxy@ for the
 -          -- cross compiler. That one needs to be compiled by the bootstrap
 -          -- compiler as it needs to run on the host. Hence @iserv@ needs
 -          -- @GHCi.TH@, @GHCi.Message@, @GHCi.Run@, and @GHCi.Server@ from
 -          -- @ghci@. And those are behind the @-finternal-interpreter@ flag.
 -          --
 -          -- But it may not build if we have made some changes to ghci's
 -          -- dependencies (see #16051).
 -          --
 -          -- To fix this properly Hadrian would need to:
 -          --   * first build a compiler for the build platform (stage1 is enough)
 -          --   * use it as a bootstrap compiler to build the stage1 cross-compiler
 -          --
 -          -- The issue is that "configure" would have to be executed twice (for
 -          -- the build platform and for the cross-platform) and Hadrian would
 -          -- need to be fixed to support two different stage1 compilers.
 -          --
 -          -- The workaround we use is to check if the bootstrap compiler has
 -          -- the same version as the one we are building. In this case we can
 -          -- avoid the first step above and directly build with
 -          -- `-finternal-interpreter`.
 -          --
 -          -- TODO: Note that in that case we also do not need to build most of
 -          -- the Stage1 libraries, as we already know that the bootstrap
 -          -- compiler comes with the same versions as the one we are building.
 -          --
 -            builder (Cabal Setup) ? cabalExtraDirs ffiIncludeDir ffiLibraryDir
 +          [ builder (Cabal Setup) ? cabalExtraDirs ffiIncludeDir ffiLibraryDir
            , builder (Cabal Flags) ? mconcat
 -            [ ifM stage0
 -                (andM [cross, bootCross] `cabalFlag` "internal-interpreter")
 -                (arg "internal-interpreter")
 -            , stage0 `cabalFlag` "bootstrap"
 +            [ stage0 `cabalFlag` "bootstrap"
+             ]
+           ]

libraries/ghci/GHCi/Run.hs

@@ -260,7 +260,11 @@ sandboxIO opts io = do
  --
  rethrow :: EvalOpts -> IO a -> IO a
  rethrow EvalOpts{..} io =
 +#if MIN_VERSION_base(4,20,0)
    catchNoPropagate io $ \(ExceptionWithContext cx se) -> do
 +#else
 +  catch io $ \se -> do
 +#endif
      -- If -fbreak-on-error, we break unconditionally,
      --  but with care of not breaking twice
      if breakOnError && not breakOnException
@@ -271,7 +275,11 @@ rethrow EvalOpts{..} io =
                 Just UserInterrupt -> return ()
                 -- In any other case, we don't want to break
                 _ -> poke exceptionFlag 0
 +#if MIN_VERSION_base(4,20,0)
      rethrowIO (ExceptionWithContext cx se)
 +#else
 +    throwIO se
 +#endif
  --
  -- While we're waiting for the sandbox thread to return a result, if

libraries/ghci/ghci.cabal.in

@@ -17,11 +17,6 @@ cabal-version:  >=1.10
  build-type:     Simple
  extra-source-files: changelog.md
 -Flag internal-interpreter
 -    Description: Build with internal interpreter support.
 -    Default: False
 -    Manual: True
+-
  Flag bootstrap
          Description:
            Enabled when building the stage1 compiler in order to vendor the in-tree
@@ -56,23 +51,19 @@ library
          TupleSections
          UnboxedTuples
 -    if flag(internal-interpreter)
 -        CPP-Options: -DHAVE_INTERNAL_INTERPRETER
 +    if !arch(javascript)
          exposed-modules:
 -            GHCi.Run
 -            GHCi.Debugger
 -            GHCi.CreateBCO
 -            GHCi.ObjLink
 -            GHCi.Signals
 -            GHCi.StaticPtrTable
 -            GHCi.TH
 -            GHCi.Server
+-
 -        if !arch(javascript)
 -          exposed-modules:
 -            GHCi.InfoTable
 +          GHCi.InfoTable
      exposed-modules:
 +        GHCi.Run
 +        GHCi.Debugger
 +        GHCi.CreateBCO
 +        GHCi.ObjLink
 +        GHCi.Signals
 +        GHCi.StaticPtrTable
 +        GHCi.TH
 +        GHCi.Server
          GHCi.BreakArray
          GHCi.BinaryArray
          GHCi.Message