Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/compiler-rt/test/tsan/Darwin/gcd-groups-norace.mm

@@ -0,0 +1,53 @@
+// RUN: %clang_tsan %s -o %t -framework Foundation
+// RUN: %run %t 2>&1 | FileCheck %s
+
+#import <Foundation/Foundation.h>
+
+#import "../test.h"
+
+long global;
+
+int main() {
+  NSLog(@"Hello world.");
+  NSLog(@"addr=%p\n", &global);
+
+  dispatch_queue_t q = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
+  global = 42;
+
+  dispatch_group_t g = dispatch_group_create();
+  dispatch_group_async(g, q, ^{
+    global = 43;
+  });
+  dispatch_group_wait(g, DISPATCH_TIME_FOREVER);
+
+  global = 44;
+
+  dispatch_group_enter(g);
+  dispatch_async(q, ^{
+    global = 45;
+    dispatch_group_leave(g);
+  });
+  dispatch_group_wait(g, DISPATCH_TIME_FOREVER);
+
+  global = 46;
+
+  dispatch_group_enter(g);
+  dispatch_async(q, ^{
+    global = 47;
+    dispatch_group_leave(g);
+  });
+  dispatch_group_notify(g, q, ^{
+    global = 48;
+
+    dispatch_sync(dispatch_get_main_queue(), ^{
+      CFRunLoopStop(CFRunLoopGetCurrent());
+    });
+  });
+
+  CFRunLoopRun();
+  NSLog(@"Done.");
+}
+
+// CHECK: Hello world.
+// CHECK: Done.
+// CHECK-NOT: WARNING: ThreadSanitizer