[logging] Avoid logging cancellation as warnings/errors

Sources/SourceKitD/SourceKitD.swift

@@ -73,13 +73,12 @@ extension SourceKitD {
 
     let resp = SKDResponse(api.send_request_sync(req.dict), sourcekitd: self)
 
+    logResponse(resp)
+
     guard let dict = resp.value else {
-      log(resp.description, level: .error)
       throw resp.error!
     }
 
-    logAsync(level: .debug) { _ in dict.description }
-
     return dict
   }
 
@@ -98,16 +97,15 @@ extension SourceKitD {
 
       let resp = SKDResponse(_resp, sourcekitd: self)
 
+      logResponse(resp)
+
       guard let dict = resp.value else {
-        log(resp.description, level: .error)
         queue.async {
          reply(.failure(resp.error!))
         }
         return
       }
 
-      logAsync(level: .debug) { _ in dict.description }
-
       queue.async {
         reply(.success(dict))
       }
@@ -117,6 +115,16 @@ extension SourceKitD {
   }
 }
 
+private func logResponse(_ response: SKDResponse) {
+  if let value = response.value {
+    logAsync(level: .debug) { _ in value.description }
+  } else if case .requestCancelled = response.error! {
+    log(response.description, level: .debug)
+  } else {
+    log(response.description, level: .error)
+  }
+}
+
 /// A sourcekitd notification handler in a class to allow it to be uniquely referenced.
 public protocol SKDNotificationHandler: AnyObject {
   func notification(_: SKDResponse) -> Void

Sources/SourceKitLSP/Swift/CursorInfo.swift

@@ -45,7 +45,7 @@ struct CursorInfo {
 }
 
 /// An error from a cursor info request.
-enum CursorInfoError: Error {
+enum CursorInfoError: Error, Equatable {
 
   /// The given URL is not a known document.
   case unknownDocument(DocumentURI)

Sources/SourceKitLSP/Swift/SwiftLanguageServer.swift

@@ -414,7 +414,7 @@ extension SwiftLanguageServer {
     let position = req.params.position
     cursorInfo(uri, position..<position) { result in
       guard let cursorInfo: CursorInfo = result.success ?? nil else {
-        if let error = result.failure {
+        if let error = result.failure, error != .responseError(.cancelled) {
           log("cursor info failed \(uri):\(position): \(error)", level: .warning)
         }
         return req.reply(nil)