Prevent clang from optimizing away 2 variables.

base/tools_sanity_unittest.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/atomicops.h"
 #include "base/message_loop.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "base/threading/thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 66 matching lines @@
   MakeSomeErrors(foo, 10);
   free(foo);
   foo[5] = 0;  // Use after free. This won't break anything under Valgrind.
 }
 
 TEST(ToolsSanityTest, ArrayDeletedWithoutBraces) {
   // This test may corrupt memory if not run under Valgrind.
   if (!RunningOnValgrind())
     return;
 
-  int *foo = new int[10];
+  // Without the |volatile|, clang optimizes away the next two lines.
+  int* volatile foo = new int[10];
   delete foo;
 }
 
 TEST(ToolsSanityTest, SingleElementDeletedWithBraces) {
   // This test may corrupt memory if not run under Valgrind.
   if (!RunningOnValgrind())
     return;
 
-  int *foo = new int;
+  // Without the |volatile|, clang optimizes away the next two lines.
+  int* volatile foo = new int;
   delete [] foo;
 }
 
 
 namespace {
 
 // We use caps here just to ensure that the method name doesn't interfere with
 // the wildcarded suppressions.
 class TOOLS_SANITY_TEST_CONCURRENT_THREAD : public PlatformThread::Delegate {
  public:
@@ skipping 69 matching lines @@
 
 TEST(ToolsSanityTest, AtomicsAreIgnored) {
   base::subtle::Atomic32 shared = 0;
   ReleaseStoreThread thread1(&shared);
   AcquireLoadThread thread2(&shared);
   RunInParallel(&thread1, &thread2);
   EXPECT_EQ(kMagicValue, shared);
 }
 
 }  // namespace base