Enable strict aliasing warnings

CMakeLists.txt

@@ -40,15 +40,16 @@ add_cxx_compiler_flag(-pedantic-errors)
 add_cxx_compiler_flag(-Wshorten-64-to-32)
 add_cxx_compiler_flag(-Wfloat-equal)
 add_cxx_compiler_flag(-Wzero-as-null-pointer-constant)
+add_cxx_compiler_flag(-fstrict-aliasing)
+if (HAVE_CXX_FLAG_FSTRICT_ALIASING)
+  add_cxx_compiler_flag(-Wstrict-aliasing)
+endif()
 add_cxx_compiler_flag(-Wthread-safety)
 if (HAVE_WTHREAD_SAFETY)
   add_definitions(-DHAVE_WTHREAD_SAFETY)
   cxx_feature_check(THREAD_SAFETY_ATTRIBUTES)
 endif()
 
-# Release flags
-add_cxx_compiler_flag(-fno-strict-aliasing RELEASE)
-
 # Link time optimisation
 if (BENCHMARK_ENABLE_LTO)
   add_cxx_compiler_flag(-flto)