bugfix: Fix axom's MSVC with OpenMP build

include/RAJA/internal/ThreadUtils_CPU.hpp

@@ -24,7 +24,9 @@
 #include "RAJA/config.hpp"
 
 #include "RAJA/pattern/thread.hpp"
+#if defined(RAJA_ENABLE_OPENMP)
 #include "RAJA/policy/openmp/thread.hpp"
+#endif
 #include "RAJA/policy/sequential/thread.hpp"
 
 namespace RAJA

include/RAJA/policy/openmp/forall.hpp

@@ -82,6 +82,12 @@ forall_impl(resources::Host host_res,
   }
   else
   {
+// This branch handles the case of an OpenMP reduction through the RAJA::kernel
+// abstraction. MSVC is not supported in this case.
+#if defined(RAJA_COMPILER_MSVC)
+    static_assert(false, "MSVC does not support an OpenMP reduction through "
+                         "the RAJA::kernel abstraction");
+#else
     auto reducers_tuple = loop_body.data.param_tuple;
 
     using EXEC_POL = camp::decay<InnerPolicy>;
@@ -110,6 +116,7 @@ forall_impl(resources::Host host_res,
       }
     }
     RAJA::expt::detail::resolve_params<EXEC_POL>(reducers_tuple);
+#endif
   }
   return resources::EventProxy<resources::Host>(host_res);
 }

include/RAJA/policy/thread_auto.hpp

@@ -25,6 +25,7 @@
 #include "RAJA/util/macros.hpp"
 
 #ifdef RAJA_OPENMP_ACTIVE
+#include <omp.h>
 #include "RAJA/policy/openmp/policy.hpp"
 #endif