Move Development.IDE.Session into ghcide itself

Sublibraries do not seem to play well. Hide this behind the ghc-lib flag
so that the Haskell specific hie-bios stuff can be disabled

Note that we need to put the template-haskell part of this module into a
separate module because of an access exception when compiling with
Stack, GHC 8.10.1 and Windows.

.hlint.yaml

@@ -84,6 +84,8 @@
     - Development.IDE.GHC.Util
     - Development.IDE.Import.FindImports
     - Development.IDE.LSP.Outline
+    - Development.IDE.Session
+    - Development.IDE.Session.VersionCheck
     - Development.IDE.Spans.Calculate
     - Development.IDE.Spans.Documentation
     - Development.IDE.Spans.Common

ghcide.cabal

@@ -1,4 +1,4 @@
-cabal-version:      3.0
+cabal-version:      1.20
 build-type:         Simple
 category:           Development
 name:               ghcide
@@ -79,7 +79,14 @@ library
       build-depends:
         ghc-boot-th,
         ghc-boot,
-        ghc >= 8.4
+        ghc >= 8.4,
+        -- These dependencies are used by Development.IDE.Session and are
+        -- Haskell specific. So don't use them when building with -fghc-lib!
+        ghc-check,
+        ghc-paths,
+        cryptohash-sha1 >=0.11.100 && <0.12,
+        hie-bios == 0.6.*,
+        base16-bytestring >=0.1.1 && <0.2
     if os(windows)
       build-depends:
         Win32
@@ -135,6 +142,16 @@ library
         Development.IDE.Plugin
         Development.IDE.Plugin.Completions
         Development.IDE.Plugin.CodeAction
+
+    -- Unfortunately, we cannot use loadSession with ghc-lib since hie-bios uses
+    -- the real GHC library and the types are incompatible. Furthermore, when
+    -- building with ghc-lib we need to make this Haskell agnostic, so no
+    -- hie-bios!
+    if !flag(ghc-lib)
+      exposed-modules:
+        Development.IDE.Session
+      other-modules:
+        Development.IDE.Session.VersionCheck
     other-modules:
         Development.IDE.Core.Compile
         Development.IDE.Core.Preprocessor
@@ -174,41 +191,10 @@ library
         Development.IDE.GHC.HieAst
         Development.IDE.GHC.HieBin
     ghc-options: -Wall -Wno-name-shadowing
-
-library ghcide-session-loader
-    visibility: public
-    default-language: Haskell2010
-    hs-source-dirs: session-loader
-    exposed-modules:
-        Development.IDE.Session
-    ghc-options: -Wall -Wno-name-shadowing
-    build-depends:
-        base == 4.*,
-        aeson,
-        async,
-        base16-bytestring >=0.1.1 && <0.2,
-        bytestring,
-        containers,
-        cryptohash-sha1 >=0.11.100 && <0.12,
-        directory,
-        extra,
-        filepath,
-        ghc,
-        ghc-check,
-        ghc-paths,
-        ghcide,
-        haskell-lsp,
-        haskell-lsp-types,
-        hie-bios >= 0.6.0 && < 0.7,
-        safe-exceptions,
-        shake,
-        text,
-        time,
-        unordered-containers
-    -- We can't build this with ghc-lib since it interfaces with hie-bios which
-    -- uses plain ghc types
-    if flag(ghc-lib)
-        buildable: False
+    -- This is needed to prevent a GHC crash when building
+    -- Development.IDE.Session with stack on 8.10.1 on Windows
+    if (impl(ghc > 8.9) && os(windows))
+      ghc-options: -fexternal-interpreter
 
 executable ghcide-test-preprocessor
     default-language: Haskell2010
@@ -277,7 +263,6 @@ executable ghcide
         directory,
         extra,
         filepath,
-        ghcide-session-loader,
         gitrev,
         hashable,
         haskell-lsp,

hie.yaml

@@ -10,8 +10,6 @@ cradle:
               component: "ghcide:lib:ghcide"
             - path: "./exe"
               component: "ghcide:exe:ghcide"
-            - path: "./session-loader"
-              component: "ghcide:lib:ghcide-session-loader"
             - path: "./test"
               component: "ghcide:test:ghcide-tests"
             - path: "./bench"

session-loader/Development/IDE/Session.hs → src/Development/IDE/Session.hs

@@ -1,16 +1,19 @@
-{-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE NamedFieldPuns #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TemplateHaskell #-}
-{-# LANGUAGE TupleSections #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE CPP #-}
 
 {-|
 The logic for setting up a ghcide session by tapping into hie-bios.
 -}
-module Development.IDE.Session (loadSession) where
+module Development.IDE.Session
+#ifndef GHC_LIB
+(loadSession)
+#endif
+where
+
+-- Unfortunately, we cannot use loadSession with ghc-lib since hie-bios uses
+-- the real GHC library and the types are incompatible. Furthermore, when
+-- building with ghc-lib we need to make this Haskell agnostic, so no hie-bios!
+#ifndef GHC_LIB
 
 import Control.Concurrent.Async
 import Control.Concurrent.Extra
@@ -36,24 +39,20 @@ import Data.Version
 import Development.IDE.Core.OfInterest
 import Development.IDE.Core.Shake
 import Development.IDE.GHC.Util
+import Development.IDE.Session.VersionCheck
 import Development.IDE.Types.Diagnostics
 import Development.IDE.Types.Location
 import Development.IDE.Types.Logger
 import Development.IDE.Types.Options
 import Development.Shake (Action)
 import GHC.Check
--- Only use this for checking against the compile time GHC libDir!
--- Use getRuntimeGhcLibDir from hie-bios instead for everything else
--- otherwise binaries will not be distributable since paths will be baked into them
-import qualified GHC.Paths
 import HIE.Bios
 import HIE.Bios.Environment hiding (getCacheDir)
 import HIE.Bios.Types
 import Language.Haskell.LSP.Core
 import Language.Haskell.LSP.Messages
 import Language.Haskell.LSP.Types
 import System.Directory
-import System.Environment
 import System.FilePath
 import System.Info
 import System.IO
@@ -66,10 +65,11 @@ import Module
 import NameCache
 import Packages
 
--- | Given a directory, return a Shake 'Action' which setups an 'IdeGhcSession'.
+-- | Given a root directory, return a Shake 'Action' which setups an
+-- 'IdeGhcSession' given a file.
 -- Some of the many things this does:
 --
--- * Find the cradle for the directory
+-- * Find the cradle for the file
 -- * Get the session options,
 -- * Get the GHC lib directory
 -- * Make sure the GHC compiletime and runtime versions match
@@ -452,13 +452,13 @@ data ComponentInfo = ComponentInfo
   -- | Internal units, such as local libraries, that this component
   -- is loaded with. These have been extracted from the original
   -- ComponentOptions.
-  , componentInternalUnits :: [InstalledUnitId]
+  , _componentInternalUnits :: [InstalledUnitId]
   -- | All targets of this components.
   , componentTargets :: [Target]
   -- | Filepath which caused the creation of this component
   , componentFP :: NormalizedFilePath
   -- | Component Options used to load the component.
-  , componentCOptions :: ComponentOptions
+  , _componentCOptions :: ComponentOptions
   -- | Maps cradle dependencies, such as `stack.yaml`, or `.cabal` file
   -- to last modification time. See Note [Multi Cradle Dependency Info]
   , componentDependencyInfo :: DependencyInfo
@@ -589,13 +589,8 @@ notifyCradleLoaded fp =
 cradleLoadedMethod :: T.Text
 cradleLoadedMethod = "ghcide/cradle/loaded"
 
-
-
 ----------------------------------------------------------------------------------------------------
 
-ghcVersionChecker :: GhcVersionChecker
-ghcVersionChecker = $$(makeGhcVersionChecker (fromMaybe GHC.Paths.libdir <$> lookupEnv "NIX_GHC_LIBDIR"))
-
 data PackageSetupException
     = PackageSetupException
         { message     :: !String
@@ -643,3 +638,5 @@ showPackageSetupException (PackageCheckFailed BasePackageAbiMismatch{..}) = unwo
 renderPackageSetupException :: FilePath -> PackageSetupException -> (NormalizedFilePath, ShowDiagnostic, Diagnostic)
 renderPackageSetupException fp e =
     ideErrorWithSource (Just "cradle") (Just DsError) (toNormalizedFilePath' fp) (T.pack $ showPackageSetupException e)
+
+#endif

src/Development/IDE/Session/VersionCheck.hs

@@ -0,0 +1,27 @@
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE CPP #-}
+
+-- | This module exists to circumvent a compile time exception on Windows with
+-- Stack and GHC 8.10.1. It's just been pulled out from Development.IDE.Session.
+-- See https://github.com/digital-asset/ghcide/pull/697
+module Development.IDE.Session.VersionCheck
+#ifndef GHC_LIB
+(ghcVersionChecker)
+#endif
+
+where
+
+#ifndef GHC_LIB
+
+import Data.Maybe
+import GHC.Check
+-- Only use this for checking against the compile time GHC libDir!
+-- Use getRuntimeGhcLibDir from hie-bios instead for everything else
+-- otherwise binaries will not be distributable since paths will be baked into them
+import qualified GHC.Paths
+import System.Environment
+
+ghcVersionChecker :: GhcVersionChecker
+ghcVersionChecker = $$(makeGhcVersionChecker (fromMaybe GHC.Paths.libdir <$> lookupEnv "NIX_GHC_LIBDIR"))
+
+#endif