Move CheckedIndex to a new SemanticIndex module

Author: ahoppen

Package.swift

@@ -168,6 +168,18 @@ let package = Package(
       ]
     ),
 
+    // MARK: SemanticIndex
+
+    .target(
+      name: "SemanticIndex",
+      dependencies: [
+        "LSPLogging",
+        "SKCore",
+        .product(name: "IndexStoreDB", package: "indexstore-db"),
+      ],
+      exclude: ["CMakeLists.txt"]
+    ),
+
     // MARK: SKCore
     // Data structures and algorithms useful across the project, but not necessarily
     // suitable for use in other packages.
@@ -303,6 +315,7 @@ let package = Package(
         "LanguageServerProtocol",
         "LanguageServerProtocolJSONRPC",
         "LSPLogging",
+        "SemanticIndex",
         "SKCore",
         "SKSupport",
         "SKSwiftPMWorkspace",

Sources/SemanticIndex/CMakeLists.txt

@@ -0,0 +1,11 @@
+
+add_library(SemanticIndex STATIC
+  CheckedIndex.swift
+)
+set_target_properties(SemanticIndex PROPERTIES
+  INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_Swift_MODULE_DIRECTORY})
+target_link_libraries(SKSupport PRIVATE
+  LSPLogging
+  SKCore
+  IndexStoreDB
+  $<$<NOT:$<PLATFORM_ID:Darwin>>:Foundation>)

Sources/SourceKitLSP/CheckedIndex.swift renamed to Sources/SemanticIndex/CheckedIndex.swift

@@ -15,6 +15,15 @@ import IndexStoreDB
 import LSPLogging
 import LanguageServerProtocol
 
+/// Essentially a `DocumentManager` from the `SourceKitLSP` module.
+///
+/// Protocol is needed because the `SemanticIndex` module is lower-level than the `SourceKitLSP` module.
+public protocol InMemoryDocumentManager {
+  /// Returns true if the file at the given URL has a different content in the document manager than on-disk. This is
+  /// the case if the user made edits to the file but didn't save them yet.
+  func fileHasInMemoryModifications(_ url: URL) -> Bool
+}
+
 public enum IndexCheckLevel {
   /// Consider the index out-of-date only if the source file has been deleted on disk.
   ///
@@ -31,7 +40,7 @@ public enum IndexCheckLevel {
 
   /// Consider the index out-of-date if the source file has been deleted or modified on disk or if there are
   /// in-memory modifications in the given `DocumentManager`.
-  case inMemoryModifiedFiles(DocumentManager)
+  case inMemoryModifiedFiles(InMemoryDocumentManager)
 }
 
 /// A wrapper around `IndexStoreDB` that checks if returned symbol occurrences are up-to-date with regard to a
@@ -250,7 +259,7 @@ private struct IndexOutOfDateChecker {
   /// `documentManager` must always be the same between calls to `hasFileInMemoryModifications` since it is not part of
   /// the cache key. This is fine because we always assume the `documentManager` to come from the associated value of
   /// `CheckLevel.imMemoryModifiedFiles`, which is constant.
-  private mutating func fileHasInMemoryModifications(_ url: URL, documentManager: DocumentManager) -> Bool {
+  private mutating func fileHasInMemoryModifications(_ url: URL, documentManager: InMemoryDocumentManager) -> Bool {
     if let cached = fileHasInMemoryModificationsCache[url] {
       return cached
     }
@@ -305,19 +314,3 @@ private struct IndexOutOfDateChecker {
     return fileExists
   }
 }
-
-extension DocumentManager {
-  /// Returns true if the file at the given URL has a different content in the document manager than on-disk. This is
-  /// the case if the user made edits to the file but didn't save them yet.
-  func fileHasInMemoryModifications(_ url: URL) -> Bool {
-    guard let document = try? latestSnapshot(DocumentURI(url)) else {
-      return false
-    }
-
-    guard let onDiskFileContents = try? String(contentsOf: url, encoding: .utf8) else {
-      // If we can't read the file on disk, it can't match any on-disk state, so it's in-memory state
-      return true
-    }
-    return onDiskFileContents != document.lineTable.content
-  }
-}

Sources/SourceKitLSP/CMakeLists.txt

@@ -62,6 +62,7 @@ target_link_libraries(SourceKitLSP PUBLIC
   LanguageServerProtocol
   LanguageServerProtocolJSONRPC
   LSPLogging
+  SemanticIndex
   SKCore
   SKSupport
   SKSwiftPMWorkspace

Sources/SourceKitLSP/DocumentManager.swift

@@ -14,6 +14,7 @@ import Dispatch
 import LSPLogging
 import LanguageServerProtocol
 import SKSupport
+import SemanticIndex
 import SwiftSyntax
 
 /// An immutable snapshot of a document at a given time.
@@ -83,7 +84,7 @@ public final class Document {
   }
 }
 
-public final class DocumentManager {
+public final class DocumentManager: InMemoryDocumentManager {
 
   public enum Error: Swift.Error {
     case alreadyOpen(DocumentURI)
@@ -187,6 +188,18 @@ public final class DocumentManager {
       return document.latestSnapshot
     }
   }
+
+  public func fileHasInMemoryModifications(_ url: URL) -> Bool {
+    guard let document = try? latestSnapshot(DocumentURI(url)) else {
+      return false
+    }
+
+    guard let onDiskFileContents = try? String(contentsOf: url, encoding: .utf8) else {
+      // If we can't read the file on disk, it can't match any on-disk state, so it's in-memory state
+      return true
+    }
+    return onDiskFileContents != document.lineTable.content
+  }
 }
 
 extension DocumentManager {

Sources/SourceKitLSP/IndexStoreDB+MainFilesProvider.swift

@@ -14,6 +14,7 @@ import Foundation
 import LSPLogging
 import LanguageServerProtocol
 import SKCore
+import SemanticIndex
 
 extension UncheckedIndex {
   public func mainFilesContainingFile(_ uri: DocumentURI) -> Set<DocumentURI> {

Sources/SourceKitLSP/Rename.swift

@@ -14,6 +14,7 @@ import IndexStoreDB
 import LSPLogging
 import LanguageServerProtocol
 import SKSupport
+import SemanticIndex
 import SourceKitD
 import SwiftSyntax
 

Sources/SourceKitLSP/SourceKitLSPServer.swift

@@ -20,6 +20,7 @@ import PackageLoading
 import SKCore
 import SKSupport
 import SKSwiftPMWorkspace
+import SemanticIndex
 import SourceKitD
 
 import struct PackageModel.BuildFlags

Sources/SourceKitLSP/Workspace.swift

@@ -16,6 +16,7 @@ import LanguageServerProtocol
 import SKCore
 import SKSupport
 import SKSwiftPMWorkspace
+import SemanticIndex
 
 import struct TSCBasic.AbsolutePath
 import struct TSCBasic.RelativePath