tsan: add a test that used to crash, fixed by r180180.

llvm-svn: 180251

compiler-rt/lib/tsan/lit_tests/oob_race.cc

@@ -0,0 +1,24 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %t 2>&1 | FileCheck %s
+#include <pthread.h>
+#include <stdio.h>
+
+const long kOffset = 64*1024;
+
+void *Thread(void *p) {
+  ((char*)p)[-kOffset] = 43;
+  return 0;
+}
+
+int main() {
+  char *volatile p0 = new char[16];
+  delete[] p0;
+  char *p = new char[32];
+  pthread_t th;
+  pthread_create(&th, 0, Thread, p);
+  p[-kOffset] = 42;
+  pthread_join(th, 0);
+}
+
+// Used to crash with CHECK failed.
+// CHECK: WARNING: ThreadSanitizer: data race
+