[NFC][sanitizer] Add basic hash test

Differential Revision: https://reviews.llvm.org/D111176

Author: vitalybuka

compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt

@@ -18,6 +18,7 @@ set(SANITIZER_UNITTESTS
   sanitizer_deadlock_detector_test.cpp
   sanitizer_flags_test.cpp
   sanitizer_format_interceptor_test.cpp
+  sanitizer_hash_test.cpp
   sanitizer_ioctl_test.cpp
   sanitizer_libc_test.cpp
   sanitizer_linux_test.cpp

compiler-rt/lib/sanitizer_common/tests/sanitizer_hash_test.cpp

@@ -0,0 +1,34 @@
+//===-- sanitizer_hash_test.cpp -------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of Sanitizers.
+//
+//===----------------------------------------------------------------------===//
+#include "sanitizer_common/sanitizer_hash.h"
+
+#include "gtest/gtest.h"
+
+namespace __sanitizer {
+
+// Tests matche a few hashes generated by https://github.com/aappleby/smhasher.
+
+TEST(SanitizerCommon, Hash32Seed) {
+  EXPECT_EQ(MurMur2HashBuilder(0).get(), 275646681u);
+  EXPECT_EQ(MurMur2HashBuilder(1).get(), 3030210376u);
+  EXPECT_EQ(MurMur2HashBuilder(3).get(), 1816185114u);
+}
+
+TEST(SanitizerCommon, Hash32Add) {
+  MurMur2HashBuilder h(123 * sizeof(u32));
+  for (u32 i = 0; i < 123; ++i) h.add(i);
+  EXPECT_EQ(h.get(), 351963665u);
+  for (u32 i = 0; i < 123; ++i) h.add(-i);
+  EXPECT_EQ(h.get(), 2640061027u);
+}
+
+}  // namespace __sanitizer