Drop support for GHC 8.10

Per our support policy, we should now deprecated 8.10. We might not want
to do this immediately, but this PR implements it.

TODO:
- Make sure CI is still all happy
- Simplify a lot of bindings that can now just be re-exports

Author: michaelpj

.github/workflows/bench.yml

@@ -46,7 +46,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ghc: ['8.10.7', '9.2.5']
+        ghc: ['9.2.5', '9.4.3']
         os: [ubuntu-latest]
 
     # This code is fitted to the strategy: assumes Linux is used ... etc,
@@ -104,7 +104,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ghc: ['8.10.7', '9.2.5']
+        ghc: ['9.2.5', '9.4.3']
         os: [ubuntu-latest]
         cabal: ['3.6']
         example: ['cabal', 'lsp-types']

.github/workflows/caching.yml

@@ -87,7 +87,6 @@ jobs:
              , "9.2.5"
              , "9.2.4"
              , "9.0.2"
-             , "8.10.7"
              ]
         os: [ "ubuntu-latest"
             , "macOS-latest"
@@ -113,7 +112,7 @@ jobs:
       # Fetching from github cache is faster than doing it from hackage
       # Sources does not change per ghc and ghc version son only doing it
       # for one matrix job (it is arbitrary)
-      - if: steps.compiled-deps.outputs.cache-hit != 'true' && runner.os == 'Linux' && matrix.ghc == '8.10.7'
+      - if: steps.compiled-deps.outputs.cache-hit != 'true' && runner.os == 'Linux' && matrix.ghc == '9.2.5'
         name: Download sources
         run: |
           cabal $cabalBuild --only-download --enable-benchmarks --enable-tests
@@ -128,7 +127,7 @@ jobs:
       # We build ghcide with benchs and test enabled to include its dependencies in the cache
       # (including shake-bench)
       # Only for the same ghc and os used in the bench workflow, so we save cache space
-      - if: steps.compiled-deps.outputs.cache-hit != 'true' && runner.os == 'Linux' && matrix.ghc == '8.10.7'
+      - if: steps.compiled-deps.outputs.cache-hit != 'true' && runner.os == 'Linux' && matrix.ghc == '9.2.5'
         name: Build ghcide benchmark
         run: |
           cabal $cabalBuild ghcide --enable-benchmarks --enable-tests

.github/workflows/flags.yml

@@ -44,9 +44,9 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        ghc: [ "9.2.5"
+        ghc: [ "9.4.3"
+             , "9.2.5"
              , "9.0.2"
-             , "8.10.7"
              ]
         os: [ "ubuntu-latest"
             ]

.github/workflows/hackage.yml

@@ -40,8 +40,8 @@ jobs:
                   "hls-qualify-imported-names-plugin", "hls-code-range-plugin",
                   "hls-cabal-fmt-plugin",
                   "haskell-language-server"]
-        ghc: [ "9.0.2"
-             , "8.10.7"
+        ghc: [ "9.2.5"
+             , "9.0.2"
              ]
         exclude:
         - ghc: "9.0.2"
@@ -136,7 +136,7 @@ jobs:
           cabal haddock --haddock-for-hackage
 
       - name: "Upload package dist tarball"
-        if: steps.get-hackage-version.outputs.exists != 'true' && matrix.ghc == '8.10.7'
+        if: steps.get-hackage-version.outputs.exists != 'true' && matrix.ghc == '9.2.5'
         uses: actions/upload-artifact@v3
         with:
           name: ${{ matrix.package }}

.github/workflows/test.yml

@@ -66,7 +66,6 @@ jobs:
              , "9.2.4"
              , "9.2.3"
              , "9.0.2"
-             , "8.10.7"
              ]
         os: [ "ubuntu-latest"
             , "macOS-latest"
@@ -94,9 +93,6 @@ jobs:
            - os: ubuntu-latest
              ghc: '9.0.2'
              test: true
-           - os: ubuntu-latest
-             ghc: '8.10.7'
-             test: true
            - os: windows-latest
              ghc: '9.4.2'
              test: true
@@ -108,9 +104,6 @@ jobs:
            - os: windows-latest
              ghc: '9.0.2'
              test: true
-           - os: windows-latest
-             ghc: '8.10.7'
-             test: true
 
     steps:
       - uses: actions/checkout@v3
@@ -270,6 +263,7 @@ jobs:
         run: cabal test hls-explicit-record-fields-plugin --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-explicit-record-fields-plugin --test-options="$TEST_OPTS"
 
       ## version needs to be limited since the tests depend on cabal-fmt which only builds using specific ghc versions
+      ## FIXME: this is unsatisfiable!
       - if: matrix.test && matrix.ghc == '8.10.7'
         name: Test hls-cabal-fmt-plugin test suite
         run: cabal test hls-cabal-fmt-plugin --flag=isolateTests --test-options="$TEST_OPTS" || cabal test hls-cabal-fmt-plugin --flag=isolateTests --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-cabal-fmt-plugin --flag=isolateTests --test-options="$TEST_OPTS"

.gitlab/tar.sh

@@ -10,7 +10,7 @@ source "$CI_PROJECT_DIR/.gitlab/setup.sh"
 case "${TARBALL_EXT}" in
     zip)
     TARBALL_PREFIX="haskell-language-server"
-		HLS_VERSION="$("$CI_PROJECT_DIR/out/haskell-language-server-8.10.7" --numeric-version)"
+		HLS_VERSION="$("$CI_PROJECT_DIR/out/haskell-language-server-9.2.5" --numeric-version)"
 		cd out/
         zip "${TARBALL_PREFIX}-${HLS_VERSION}-${TARBALL_ARCHIVE_SUFFIX}.zip" haskell-language-server-*
 		find . -type f ! -name '*.zip' -delete

docs/contributing/plugin-tutorial.md

@@ -34,7 +34,7 @@ And here is the gist of the algorithm:
 
 ## Setup
 
-To get started, let’s fetch the HLS repo and build it. You need at least GHC 8.10 for this:
+To get started, let’s fetch the HLS repo and build it. You need at least GHC 9.0 for this:
 
 ```
 git clone --recursive http://github.com/haskell/haskell-language-server hls

docs/support/ghc-version-support.md

@@ -26,7 +26,7 @@ Support status (see the support policy below for more details):
 | 9.2.(1,2)    | [1.7.0.0](https://github.com/haskell/haskell-language-server/releases/tag/1.7.0.0) | deprecated                                                                  |
 | 9.0.2        | [latest](https://github.com/haskell/haskell-language-server/releases/latest)       | full support                                                                |
 | 9.0.1        | [1.6.1.0](https://github.com/haskell/haskell-language-server/releases/tag/1.6.1.0) | deprecated                                                                  |
-| 8.10.7       | [latest](https://github.com/haskell/haskell-language-server/releases/latest)       | full support                                                                |
+| 8.10.7       | [1.9.0.0](https://github.com/haskell/haskell-language-server/releases/tag/1.9.0.0) | deprecated |
 | 8.10.6       | [1.6.1.0](https://github.com/haskell/haskell-language-server/releases/tag/1.6.1.0) | deprecated                                                                  |
 | 8.10.5       | [1.5.1](https://github.com/haskell/haskell-language-server/releases/tag/1.5.1)     | deprecated                                                                  |
 | 8.10.(4,3,2) | [1.4.0](https://github.com/haskell/haskell-language-server/releases/tag/1.4.0)     | deprecated                                                                  |

docs/troubleshooting.md

@@ -185,7 +185,7 @@ stack install haskell-language-server
 You also can leverage `ghcup compile hls`:
 
 ```bash
-ghcup compile hls -v 1.6.1.0 --ghc 8.10.7
+ghcup compile hls -v 1.9.0.0 --ghc 9.2.5
 ```
 
 ### Preprocessors

ghcide-bench/ghcide-bench.cabal

@@ -12,7 +12,7 @@ synopsis:           An LSP client for running performance experiments on HLS
 description:        An LSP client for running performance experiments on HLS
 homepage:           https://github.com/haskell/haskell-language-server/tree/master/ghcide#readme
 bug-reports:        https://github.com/haskell/haskell-language-server/issues
-tested-with:        GHC == 8.10.7 || == 9.0.2 || == 9.2.5
+tested-with:        GHC == 9.0.2 || == 9.2.5
 
 source-repository head
     type:     git

ghcide/ghcide.cabal

@@ -13,7 +13,7 @@ description:
     A library for building Haskell IDE's on top of the GHC API.
 homepage:           https://github.com/haskell/haskell-language-server/tree/master/ghcide#readme
 bug-reports:        https://github.com/haskell/haskell-language-server/issues
-tested-with:        GHC == 8.10.7 || == 9.0.2 || == 9.2.5
+tested-with:        GHC == 9.0.2 || == 9.2.5
 extra-source-files: README.md CHANGELOG.md
                     test/data/**/*.project
                     test/data/**/*.cabal
@@ -99,7 +99,7 @@ library
         unliftio-core,
         ghc-boot-th,
         ghc-boot,
-        ghc >= 8.10,
+        ghc >= 9.0,
         ghc-check >=0.5.0.8,
         ghc-paths,
         cryptohash-sha1 >=0.11.100 && <0.12,

ghcide/src/Development/IDE/Core/Compile.hs

@@ -104,7 +104,6 @@ import           System.FilePath
 import           System.IO.Extra                   (fixIO, newTempFileWithin)
 import           Unsafe.Coerce
 
-#if MIN_VERSION_ghc(9,0,1)
 import           GHC.Tc.Gen.Splice
 
 #if MIN_VERSION_ghc(9,2,1)
@@ -115,11 +114,6 @@ import           GHC.Types.TypeEnv
 import           GHC.Driver.Types
 #endif
 
-#else
-import           HscTypes
-import           TcSplice
-#endif
-
 #if MIN_VERSION_ghc(9,2,0)
 import           GHC                               (Anchor (anchor),
                                                     EpaComment (EpaComment),
@@ -470,7 +464,6 @@ mkHiFileResultCompile se session' tcm simplified_guts = catchErrs $ do
         (guts, details) <- tidyProgram tidy_opts simplified_guts
         pure (details, Just guts)
 
-#if MIN_VERSION_ghc(9,0,1)
   let !partial_iface = force $ mkPartialIface session details
 #if MIN_VERSION_ghc(9,3,0)
                                               ms
@@ -482,10 +475,6 @@ mkHiFileResultCompile se session' tcm simplified_guts = catchErrs $ do
                     Nothing
 #endif
 
-#else
-  let !partial_iface = force (mkPartialIface session details simplified_guts)
-  final_iface' <- mkFullIface session partial_iface
-#endif
   let final_iface = final_iface' {mi_globals = Nothing} -- See Note [Clearing mi_globals after generating an iface]
 
   -- Write the core file now
@@ -626,10 +615,8 @@ generateObjectCode session summary guts = do
                           session' = hscSetFlags newFlags session
 #if MIN_VERSION_ghc(9,4,2)
                       (outputFilename, _mStub, _foreign_files, _cinfos, _stgcinfos) <- hscGenHardCode session' guts
-#elif MIN_VERSION_ghc(9,0,1)
-                      (outputFilename, _mStub, _foreign_files, _cinfos) <- hscGenHardCode session' guts
 #else
-                      (outputFilename, _mStub, _foreign_files) <- hscGenHardCode session' guts
+                      (outputFilename, _mStub, _foreign_files, _cinfos) <- hscGenHardCode session' guts
 #endif
                                 (ms_location summary)
                                 fp
@@ -775,7 +762,6 @@ generateHieAsts hscEnv tcm =
     -- don't export an interface which allows for additional information to be added to hie files.
     let fake_splice_binds = Util.listToBag (map (mkVarBind unitDataConId) (spliceExpressions $ tmrTopLevelSplices tcm))
         real_binds = tcg_binds $ tmrTypechecked tcm
-#if MIN_VERSION_ghc(9,0,1)
         ts = tmrTypechecked tcm :: TcGblEnv
         top_ev_binds = tcg_ev_binds ts :: Util.Bag EvBind
         insts = tcg_insts ts :: [ClsInst]
@@ -787,19 +773,14 @@ generateHieAsts hscEnv tcm =
       Just <$>
 #endif
           GHC.enrichHie (fake_splice_binds `Util.unionBags` real_binds) (tmrRenamed tcm) top_ev_binds insts tcs
-#else
-    Just <$> GHC.enrichHie (fake_splice_binds `Util.unionBags` real_binds) (tmrRenamed tcm)
-#endif
   where
     dflags = hsc_dflags hscEnv
-#if MIN_VERSION_ghc(9,0,0)
     run ts =
 #if MIN_VERSION_ghc(9,2,0) && !MIN_VERSION_ghc(9,3,0)
         fmap (join . snd) . liftIO . initDs hscEnv ts
 #else
         id
 #endif
-#endif
 
 spliceExpressions :: Splices -> [LHsExpr GhcTc]
 spliceExpressions Splices{..} =
@@ -1218,11 +1199,7 @@ parseHeader
        => DynFlags -- ^ flags to use
        -> FilePath  -- ^ the filename (for source locations)
        -> Util.StringBuffer -- ^ Haskell module source text (full Unicode is supported)
-#if MIN_VERSION_ghc(9,0,1)
        -> ExceptT [FileDiagnostic] m ([FileDiagnostic], Located(HsModule))
-#else
-       -> ExceptT [FileDiagnostic] m ([FileDiagnostic], Located(HsModule GhcPs))
-#endif
 parseHeader dflags filename contents = do
    let loc  = mkRealSrcLoc (Util.mkFastString filename) 1 1
    case unP Compat.parseHeader (initParserState (initParserOpts dflags) contents loc) of

ghcide/src/Development/IDE/GHC/CPP.hs

@@ -19,13 +19,8 @@ import           Development.IDE.GHC.Compat      as Compat
 import           Development.IDE.GHC.Compat.Util
 import           GHC
 
-#if MIN_VERSION_ghc(9,0,0)
 import qualified GHC.Driver.Pipeline             as Pipeline
 import           GHC.Settings
-#elif MIN_VERSION_ghc (8,10,0)
-import qualified DriverPipeline                  as Pipeline
-import           ToolSettings
-#endif
 #if MIN_VERSION_ghc(9,3,0)
 import qualified GHC.Driver.Pipeline.Execute     as Pipeline
 #endif