Generic Glean-based LSP server

Author: simonmar

.github/workflows/ci.yml

@@ -190,6 +190,9 @@ jobs:
       - name: Run tests
         run: make test
 
+      - name: Build glean-lsp
+        run: make glean-lsp
+
   # check the vscode extension builds
   vscode:
     runs-on: ubuntu-latest

Makefile

@@ -325,6 +325,10 @@ glean-clang:: gen-schema glean glean.cabal cxx-libraries glean/schema/cpp/schema
 glean-hie:: glean.cabal cxx-libraries
 	$(CABAL) build hie-indexer
 
+.PHONY: glean-lsp
+glean-lsp:: glean.cabal
+	$(CABAL) build glean-lsp
+
 define bash_macros
 call_cabal() {
 	$(CABAL) "$$@"

cabal.project

@@ -11,6 +11,7 @@ packages:
     hsthrift/http/thrift-http.cabal
     glean.cabal
     glean/lang/clang/glean-clang.cabal
+    glean/lsp
 
 optional-packages:
     hsthrift/folly-clib/folly-clib.cabal
@@ -23,6 +24,8 @@ allow-newer: haskeline:base
 -- develop with -Werror on, for consistency with internal Meta CI.
 program-options
     ghc-options: -Werror
+package glean-lsp
+    ghc-options: -Werror
 
 package fb-util
     flags: +folly

glean/lsp/CHANGELOG.md

@@ -0,0 +1,5 @@
+# Revision history for glean-lsp
+
+## 0.1.0.0
+
+* First version. Released on an unsuspecting world.

glean/lsp/Data/Path.hs

@@ -0,0 +1,110 @@
+{-
+  Copyright (c) 2023 Joseph Sumabat
+
+  See glean/lsp/LICENSE
+-}
+
+module Data.Path (
+  Path (path, Path, UncheckedPath),
+  KnownPathKind (sPathKind),
+  AbsPath,
+  PathKind (..),
+  RelPath,
+  filePathToAbs,
+  unsafeFilePathToAbs,
+  filePathToRel,
+  toFilePath,
+  (</>),
+  makeRelative,
+  absToRel,
+  (<.>),
+  (-<.>),
+  filePathToAbsThrow,
+  uncheckedCoercePath,
+  relToAbsThrow,
+)
+where
+
+import Control.Monad.Catch
+import Control.Monad.IO.Class
+import Data.Aeson qualified as Aeson
+import Data.Coerce (coerce)
+import Data.Hashable (Hashable)
+import Data.String (IsString (..))
+import GHC.Stack (HasCallStack)
+import System.Directory qualified as Dir
+import System.FilePath qualified as FilePath
+import UnliftIO (stringException)
+
+-- | Rel means may be relative or absolute, absolute means must be absolute
+data PathKind = Rel | Abs
+
+data SPathKind p where
+  SRel :: SPathKind Rel
+  SAbs :: SPathKind Abs
+
+class KnownPathKind p where
+  sPathKind :: SPathKind p
+
+instance KnownPathKind Abs where
+  sPathKind = SAbs
+
+instance KnownPathKind Rel where
+  sPathKind = SRel
+
+newtype Path (p :: PathKind) = UncheckedPath {path :: FilePath}
+  deriving (Show, Eq, Ord, Hashable, Aeson.FromJSON, Aeson.ToJSON)
+
+uncheckedCoercePath :: Path p -> Path q
+uncheckedCoercePath = coerce
+
+instance IsString (Path Rel) where
+  fromString = UncheckedPath
+
+pattern Path :: FilePath -> Path p
+pattern Path p <- UncheckedPath p
+
+type AbsPath = Path Abs
+
+type RelPath = Path Rel
+
+toFilePath :: (HasCallStack) => Path p -> FilePath
+toFilePath = (.path)
+
+filePathToRel :: (HasCallStack) => FilePath -> RelPath
+filePathToRel = UncheckedPath
+
+filePathToAbs :: (HasCallStack, MonadIO m) => FilePath -> m AbsPath
+filePathToAbs p = do
+  absPath <- liftIO $ Dir.makeAbsolute p
+  pure $ UncheckedPath absPath
+
+unsafeFilePathToAbs :: (HasCallStack) => FilePath -> AbsPath
+unsafeFilePathToAbs p
+  | FilePath.isAbsolute p = UncheckedPath p
+  | otherwise = error "unsafeOsPathToAbs: path is not absolute"
+
+relToAbsThrow :: (MonadThrow m, HasCallStack) => RelPath -> m AbsPath
+relToAbsThrow (UncheckedPath p) = filePathToAbsThrow p
+
+filePathToAbsThrow :: (MonadThrow m, HasCallStack) => FilePath -> m AbsPath
+filePathToAbsThrow p
+  | FilePath.isAbsolute p = pure $ UncheckedPath p
+  | otherwise = throwM (stringException $ "filepath was not absolute: " ++ p)
+
+(</>) :: Path p -> Path Rel -> Path p
+(UncheckedPath p) </> (UncheckedPath p') = UncheckedPath (p FilePath.</> p')
+
+infixr 5 </>
+
+(<.>) :: Path p -> String -> Path p
+(UncheckedPath p) <.> ext = UncheckedPath (p FilePath.<.> ext)
+
+(-<.>) :: Path p -> String -> Path p
+(UncheckedPath p) -<.> ext = UncheckedPath (p FilePath.-<.> ext)
+
+absToRel :: AbsPath -> RelPath
+absToRel (UncheckedPath p) = UncheckedPath p
+
+makeRelative :: Path p -> Path q -> Path Rel
+makeRelative (UncheckedPath p) (UncheckedPath q) = UncheckedPath (FilePath.makeRelative p q)