1 files changed, 40 insertions, 0 deletions
diff --git a/lib/tsan/lit_tests/memcpy_race.cc b/lib/tsan/lit_tests/memcpy_race.cc
new file mode 100644
index 000000000000..806740dda241
--- /dev/null
+++ b/lib/tsan/lit_tests/memcpy_race.cc
@@ -0,0 +1,40 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %t 2>&1 | FileCheck %s
+#include <pthread.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+char *data = new char[10];
+char *data1 = new char[10];
+char *data2 = new char[10];
+
+void *Thread1(void *x) {
+  memcpy(data+5, data1, 1);
+  return NULL;
+}
+
+void *Thread2(void *x) {
+  sleep(1);
+  memcpy(data+3, data2, 4);
+  return NULL;
+}
+
+int main() {
+  fprintf(stderr, "addr=%p\n", &data[5]);
+  pthread_t t[2];
+  pthread_create(&t[0], NULL, Thread1, NULL);
+  pthread_create(&t[1], NULL, Thread2, NULL);
+  pthread_join(t[0], NULL);
+  pthread_join(t[1], NULL);
+  return 0;
+}
+
+// CHECK: addr=[[ADDR:0x[0-9,a-f]+]]
+// CHECK: WARNING: ThreadSanitizer: data race
+// CHECK:   Write of size 1 at [[ADDR]] by thread T2:
+// CHECK:     #0 memcpy
+// CHECK:     #1 Thread2
+// CHECK:   Previous write of size 1 at [[ADDR]] by thread T1:
+// CHECK:     #0 memcpy
+// CHECK:     #1 Thread1