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

@@ -47,8 +47,8 @@ jobs:
       fail-fast: false
       matrix:
         ghc:
-          - '8.10'
           - '9.2'
+          - '9.4'
         os:
           - ubuntu-latest
 
@@ -115,7 +115,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ghc: ['8.10', '9.2']
+        ghc: ['9.2', '9.4']
         os: [ubuntu-latest]
         cabal: ['3.10']
         example: ['cabal', 'lsp-types']

.github/workflows/caching.yml

@@ -102,7 +102,7 @@ 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'
+      - if: steps.compiled-deps.outputs.cache-hit != 'true' && runner.os == 'Linux' && matrix.ghc == '9.2'
         name: Download sources
         run: |
           cabal $cabalBuild --only-download --enable-benchmarks --enable-tests
@@ -117,7 +117,7 @@ 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'
+      - if: steps.compiled-deps.outputs.cache-hit != 'true' && runner.os == 'Linux' && matrix.ghc == '9.2'
         name: Build ghcide benchmark
         run: |
           cabal $cabalBuild ghcide --enable-benchmarks --enable-tests

.github/workflows/supported-ghc-versions.json

@@ -1 +1 @@
-[ "9.6", "9.4" , "9.2" , "9.0" , "8.10" ]
+[ "9.6", "9.4" , "9.2" , "9.0" ]

.github/workflows/test.yml

@@ -220,7 +220,7 @@ jobs:
         run: cabal test hls-explicit-record-fields-plugin --test-options="$TEST_OPTS" || cabal test hls-explicit-record-fields-plugin --test-options="$TEST_OPTS"
 
       ## version needs to be limited since the tests depend on cabal-fmt which only builds using specific ghc versions
-      - if: matrix.test && matrix.ghc == '8.10'
+      - if: matrix.test && matrix.ghc == '9.2'
         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"
 
@@ -232,7 +232,7 @@ jobs:
         name: Test hls-retrie-plugin test suite
         run: cabal test hls-retrie-plugin --test-options="$TEST_OPTS" || cabal test hls-retrie-plugin --test-options="$TEST_OPTS"
 
-      - if: matrix.test && matrix.ghc != '8.10' && matrix.ghc != '9.0'
+      - if: matrix.test && matrix.ghc != '9.0'
         name: Test hls-overloaded-record-dot-plugin test suite
         run: cabal test hls-overloaded-record-dot-plugin --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-overloaded-record-dot-plugin --test-options="$TEST_OPTS"
 

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

@@ -31,7 +31,7 @@ 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       | [2.2.0.0](https://github.com/haskell/haskell-language-server/releases/tag/2.2.0.0)   | full support                                                                |
 | 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                                                                  |
@@ -42,7 +42,6 @@ Support status (see the support policy below for more details):
 | 8.6.5        | [1.8.0.0](https://github.com/haskell/haskell-language-server/releases/tag/1.8.0.0)   | deprecated                                                                  |
 | 8.6.4        | [1.4.0](https://github.com/haskell/haskell-language-server/releases/tag/1.4.0)       | deprecated                                                                  |
 
-
 GHC versions not in the list have never been supported by HLS.
 LTS stands for [Stackage](https://www.stackage.org/) Long Term Support.
 

docs/troubleshooting.md

@@ -189,7 +189,7 @@ 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
@@ -44,7 +44,6 @@ library
     default-language:   Haskell2010
     build-depends:
         aeson,
-        aeson-pretty,
         array,
         async,
         base == 4.*,
@@ -104,7 +103,7 @@ 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,
@@ -228,6 +227,7 @@ library
                 -Wall
                 -Wincomplete-uni-patterns
                 -Wno-unticked-promoted-constructors
+                -Wunused-packages
                 -fno-ignore-asserts
 
     if flag(ghc-patched-unboxed-bytecode)
@@ -254,9 +254,6 @@ library
     if impl(ghc >= 9.2) && flag(pedantic)
         ghc-options: -Wwarn=ambiguous-fields
 
-    if impl(ghc >= 9)
-        ghc-options: -Wunused-packages
-
     if flag(ekg)
         build-depends:
             ekg-wai,
@@ -397,10 +394,8 @@ test-suite ghcide-tests
           record-hasfield
     if impl(ghc < 9.3)
        build-depends:  ghc-typelits-knownnat
-    if impl(ghc >= 9)
-        ghc-options: -Wunused-packages
     hs-source-dirs: test/cabal test/exe test/src
-    ghc-options: -threaded -Wall -Wno-name-shadowing -O0 -Wno-unticked-promoted-constructors
+    ghc-options: -threaded -Wall -Wno-name-shadowing -O0 -Wno-unticked-promoted-constructors -Wunused-packages
     main-is: Main.hs
     other-modules:
         Development.IDE.Test.Runfiles

ghcide/session-loader/Development/IDE/Session.hs

@@ -768,7 +768,6 @@ emptyHscEnv :: IORef NameCache -> FilePath -> IO HscEnv
 #endif
 emptyHscEnv nc libDir = do
     env <- runGhc (Just libDir) getSession
-    initDynLinker env
     pure $ setNameCache nc (hscSetFlags ((hsc_dflags env){useUnicode = True }) env)
 
 data TargetDetails = TargetDetails

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

@@ -108,16 +108,9 @@ import           System.IO.Extra                   (fixIO, newTempFileWithin)
 
 -- See Note [Guidelines For Using CPP In GHCIDE Import Statements]
 
-#if !MIN_VERSION_ghc(9,0,1)
-import           HscTypes
-import           TcSplice
-#endif
-
-#if MIN_VERSION_ghc(9,0,1)
 import           GHC.Tc.Gen.Splice
-#endif
 
-#if MIN_VERSION_ghc(9,0,1) && !MIN_VERSION_ghc(9,2,1)
+#if !MIN_VERSION_ghc(9,2,1)
 import           GHC.Driver.Types
 #endif
 
@@ -525,7 +518,6 @@ mkHiFileResultCompile se session' tcm simplified_guts = catchErrs $ do
         (guts, details) <- tidyProgram tidy_opts simplified_guts
         pure (details, guts)
 
-#if MIN_VERSION_ghc(9,0,1)
   let !partial_iface = force $ mkPartialIface session
 #if MIN_VERSION_ghc(9,5,0)
                                               (cg_binds guts)
@@ -540,11 +532,6 @@ mkHiFileResultCompile se session' tcm simplified_guts = catchErrs $ do
 #if MIN_VERSION_ghc(9,4,2)
                     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, mi_usages = filterUsages (mi_usages final_iface')} -- See Note [Clearing mi_globals after generating an iface]
 
   -- Write the core file now
@@ -693,10 +680,8 @@ 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
@@ -839,7 +824,6 @@ 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]
@@ -851,19 +835,14 @@ 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 = -- ts is only used in GHC 9.2
 #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{..} =
@@ -1258,10 +1237,8 @@ parseHeader
        -> Util.StringBuffer -- ^ Haskell module source text (full Unicode is supported)
 #if MIN_VERSION_ghc(9,5,0)
        -> ExceptT [FileDiagnostic] m ([FileDiagnostic], Located(HsModule GhcPs))
-#elif MIN_VERSION_ghc(9,0,1)
-       -> ExceptT [FileDiagnostic] m ([FileDiagnostic], Located(HsModule))
 #else
-       -> ExceptT [FileDiagnostic] m ([FileDiagnostic], Located(HsModule GhcPs))
+       -> ExceptT [FileDiagnostic] m ([FileDiagnostic], Located(HsModule))
 #endif
 parseHeader dflags filename contents = do
    let loc  = mkRealSrcLoc (Util.mkFastString filename) 1 1
@@ -1774,4 +1751,4 @@ pathToModuleName = mkModuleName . map rep
   GHC numbers is identical, with the only preference being to use what is
   already there. (i.e. (`MIN_VERSION_GHC(9,2,0)` and `MIN_VERSION_GHC(9,1,0)` 
   are functionally equivalent)
--}
+-}

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

@@ -21,16 +21,9 @@ import           GHC
 
 -- See Note [Guidelines For Using CPP In GHCIDE Import Statements]
 
-#if MIN_VERSION_ghc (8,10,0) && !MIN_VERSION_ghc(9,0,0)
-import qualified DriverPipeline                  as Pipeline
-import           ToolSettings
-#endif
-
-#if MIN_VERSION_ghc(9,0,0)
 import           GHC.Settings
-#endif
 
-#if MIN_VERSION_ghc(9,0,0) && !MIN_VERSION_ghc(9,3,0)
+#if !MIN_VERSION_ghc(9,3,0)
 import qualified GHC.Driver.Pipeline             as Pipeline
 #endif