Merge pull request swiftlang#242 from DavidGoldman/dependencyhandling

Improve handling/testing of `filesDependenciesUpdated` for clangd

Author: benlangmuir

Sources/LanguageServerProtocol/Notifications/TextSynchronizationNotifications.swift

@@ -74,12 +74,19 @@ public struct DidChangeTextDocumentNotification: NotificationType, Hashable {
   /// Edits to the document.
   public var contentChanges: [TextDocumentContentChangeEvent]
 
+  /// Force the LSP to rebuild its AST for the given file. This is useful for clangd to workaround clangd's assumption that
+  /// missing header files will stay missing.
+  /// **LSP Extension from clangd**.
+  public var forceRebuild: Bool? = nil
+
   public init(
     textDocument: VersionedTextDocumentIdentifier,
-    contentChanges: [TextDocumentContentChangeEvent])
+    contentChanges: [TextDocumentContentChangeEvent],
+    forceRebuild: Bool? = nil)
   {
     self.textDocument = textDocument
     self.contentChanges = contentChanges
+    self.forceRebuild = forceRebuild
   }
 }
 

Sources/SourceKit/clangd/ClangLanguageServer.swift

@@ -129,11 +129,13 @@ extension ClangLanguageServerShim {
   }
 
   public func documentDependenciesUpdated(_ uri: DocumentURI, language: Language) {
-    // In order to tell clangd to reload an AST, we send it an empty `didChangeTextDocument`. This
-    // works well for us as the moment since clangd ignores the document version.
+    // In order to tell clangd to reload an AST, we send it an empty `didChangeTextDocument`
+    // with `forceRebuild` set in case any missing header files have been added.
+    // This works well for us as the moment since clangd ignores the document version.
     let note = DidChangeTextDocumentNotification(
       textDocument: VersionedTextDocumentIdentifier(uri, version: nil),
-      contentChanges: [])
+      contentChanges: [],
+      forceRebuild: true)
     clangd.send(note)
   }
 

Tests/INPUTS/GeneratedHeader/lib.c

@@ -0,0 +1,3 @@
+int /*libX:def*/libX(int value) {
+  return value ? 22 : 0;
+}

Tests/INPUTS/GeneratedHeader/main.c

@@ -0,0 +1,5 @@
+#include "lib-generated.h"
+
+int main(int argc, const char *argv[]) {
+  return /*libX:call:main*/libX(argc);
+}

Tests/INPUTS/GeneratedHeader/project.json

@@ -0,0 +1 @@
+{ "sources": ["main.c", "lib.c"] }

Tests/SourceKitTests/SourceKitTests.swift

@@ -235,4 +235,52 @@ final class SKTests: XCTestCase {
       fatalError("error \(finished) waiting for post-build diagnostics notification")
     }
   }
+
+  func testDependenciesUpdatedCXXTibs() throws {
+    guard let ws = try mutableSourceKitTibsTestWorkspace(name: "GeneratedHeader") else { return }
+    guard let server = ws.testServer.server else {
+      XCTFail("Unable to fetch SourceKitServer to notify for build system events.")
+      return
+    }
+
+    let moduleRef = ws.testLoc("libX:call:main")
+    let startExpectation = XCTestExpectation(description: "initial diagnostics")
+    ws.sk.handleNextNotification { (note: Notification<PublishDiagnosticsNotification>) in
+      // Expect one error:
+      // - Implicit declaration of function invalid
+      XCTAssertEqual(note.params.diagnostics.count, 1)
+      startExpectation.fulfill()
+    }
+
+    let generatedHeaderURL = moduleRef.url.deletingLastPathComponent()
+        .appendingPathComponent("lib-generated.h", isDirectory: false)
+
+    // Write an empty header file first since clangd doesn't handle missing header
+    // files without a recently upstreamed extension.
+    try "".write(to: generatedHeaderURL, atomically: true, encoding: .utf8)
+    try ws.openDocument(moduleRef.url, language: .c)
+    let started = XCTWaiter.wait(for: [startExpectation], timeout: 3)
+    if started != .completed {
+      fatalError("error \(started) waiting for initial diagnostics notification")
+    }
+
+    // Update the header file to have the proper contents for our code to build.
+    let contents = "int libX(int value);"
+    try contents.write(to: generatedHeaderURL, atomically: true, encoding: .utf8)
+    try ws.buildAndIndex()
+
+    let finishExpectation = XCTestExpectation(description: "post-build diagnostics")
+    ws.sk.handleNextNotification { (note: Notification<PublishDiagnosticsNotification>) in
+      // No more errors expected, import should resolve since we the generated header file
+      // now has the proper contents.
+      XCTAssertEqual(note.params.diagnostics.count, 0)
+      finishExpectation.fulfill()
+    }
+    server.filesDependenciesUpdated([DocumentURI(moduleRef.url)])
+
+    let finished = XCTWaiter.wait(for: [finishExpectation], timeout: 3)
+    if finished != .completed {
+      fatalError("error \(finished) waiting for post-build diagnostics notification")
+    }
+  }
 }

Tests/SourceKitTests/XCTestManifests.swift

@@ -140,6 +140,7 @@ extension SKTests {
     // to regenerate.
     static let __allTests__SKTests = [
         ("testCodeCompleteSwiftTibs", testCodeCompleteSwiftTibs),
+        ("testDependenciesUpdatedCXXTibs", testDependenciesUpdatedCXXTibs),
         ("testDependenciesUpdatedSwiftTibs", testDependenciesUpdatedSwiftTibs),
         ("testIndexShutdown", testIndexShutdown),
         ("testIndexSwiftModules", testIndexSwiftModules),