Merge pull request swiftlang#270 from benlangmuir/tsan-fix

[test] Fix data race in build system test

Author: benlangmuir

Tests/SKCoreTests/BuildSystemManagerTests.swift

@@ -380,7 +380,12 @@ final class BuildSystemManagerTests: XCTestCase {
 
 /// A simple `MainFilesProvider` that wraps a dictionary, for testing.
 private final class ManualMainFilesProvider: MainFilesProvider {
-  var mainFiles: [DocumentURI: Set<DocumentURI>] = [:]
+  let lock: DispatchQueue = DispatchQueue(label: "\(ManualMainFilesProvider.self)-lock")
+  private var _mainFiles: [DocumentURI: Set<DocumentURI>] = [:]
+  var mainFiles: [DocumentURI: Set<DocumentURI>] {
+    get { lock.sync { _mainFiles } }
+    set { lock.sync { _mainFiles = newValue } }
+  }
 
   func mainFilesContainingFile(_ file: DocumentURI) -> Set<DocumentURI> {
     if let result = mainFiles[file] {

Utilities/build-script-helper.py

@@ -114,7 +114,8 @@ def handle_invocation(swift_exec, args):
   if args.sanitize and 'undefined' in args.sanitize:
     supp = os.path.join(args.package_path, 'Utilities', 'ubsan_supressions.supp')
     env['UBSAN_OPTIONS'] = 'halt_on_error=true,suppressions=%s' % supp
-
+  if args.sanitize and 'thread' in args.sanitize:
+    env['TSAN_OPTIONS'] = 'halt_on_error=true'
 
   if args.action == 'build':
     swiftpm('build', swift_exec, swiftpm_args, env)