Base Security: fix-up overflow tests

base/security_unittest.cc

Index: base/security_unittest.cc
diff --git a/base/security_unittest.cc b/base/security_unittest.cc
index 2e865bcbcacc618443c1f3b827f454834a77a7aa..aa30f4f9cb86c834c8a9f50305e967af3b905e5e 100644
--- a/base/security_unittest.cc
+++ b/base/security_unittest.cc
@@ -34,6 +34,11 @@ namespace {
 // as something we don't need (see the comment with calloc below).
 template <typename Type>
 Type HideValueFromCompiler(volatile Type value) {
+#if defined(__GNUC__)
+  // In a GCC compatible compiler (GCC or Clang), make this compiler barrier
+  // more robust than merely using "volatile".
+  __asm__ volatile ("" : "+r" (value));
+#endif  // __GNUC__
   return value;
 }
 
@@ -139,10 +144,10 @@ TEST(SecurityTest, TCMALLOC_TEST(MemoryAllocationRestrictionsNewArray)) {
 
 // The tests bellow check for overflows in new[] and calloc().
 
-#if defined(OS_IOS) || defined(OS_WIN)
-  #define DISABLE_ON_IOS_AND_WIN(function) DISABLED_##function
+#if defined(OS_IOS)
+  #define DISABLE_ON_IOS(function) DISABLED_##function
 #else
-  #define DISABLE_ON_IOS_AND_WIN(function) function
+  #define DISABLE_ON_IOS(function) function
 #endif
 
 #if defined(ADDRESS_SANITIZER)
@@ -169,13 +174,9 @@ void OverflowTestsSoftExpectTrue(bool overflow_detected) {
   }
 }
 
-// TODO(jln): crbug.com/174947 This can't even compile on Win64.
-#if !(defined(OS_WIN) && defined(ARCH_CPU_X86_64))
-
 // Test array[TooBig][X] and array[X][TooBig] allocations for int overflows.
 // IOS doesn't honor nothrow, so disable the test there.
-// Disable on Windows, we suspect some are failing because of it.
-TEST(SecurityTest, DISABLE_ON_IOS_AND_WIN(NewOverflow)) {
+TEST(SecurityTest, DISABLE_ON_IOS(NewOverflow)) {
   const size_t kArraySize = 4096;
   // We want something "dynamic" here, so that the compiler doesn't
   // immediately reject crazy arrays.
@@ -191,13 +192,16 @@ TEST(SecurityTest, DISABLE_ON_IOS_AND_WIN(NewOverflow)) {
         char[kDynamicArraySize2][kArraySize]);
     OverflowTestsSoftExpectTrue(!array_pointer);
   }
+  // On windows, the compiler prevents static array sizes of more than
+  // 0x7fffffff (error C2148).
+#if !defined(OS_WIN) || !defined(ARCH_CPU_64_BITS)
   {
     scoped_ptr<char[][kArraySize2]> array_pointer(new (nothrow)
         char[kDynamicArraySize][kArraySize2]);
     OverflowTestsSoftExpectTrue(!array_pointer);
   }
+#endif  // !defined(OS_WIN) || !defined(ARCH_CPU_64_BITS)
 }
-#endif
 
 // Call calloc(), eventually free the memory and return whether or not
 // calloc() did succeed.