Allow HDF5 to be build in serial or parallel mode

source/ADIOS.cpp

@@ -36,12 +36,10 @@
 #include "engine/adios1/ADIOS1Writer.h"
 #endif
 
-#ifdef ADIOS_HAVE_PHDF5 // external dependencies
-#ifdef ADIOS_HAVE_MPI
+#ifdef ADIOS_HAVE_HDF5 // external dependencies
 #include "engine/hdf5/HDF5ReaderP.h"
 #include "engine/hdf5/HDF5WriterP.h"
 #endif
-#endif
 namespace adios
 {
 
@@ -194,7 +192,7 @@ std::shared_ptr<Engine> ADIOS::Open(const std::string &name,
     }
     else if (type == "HDF5Writer") // -junmin
     {
-#if defined(ADIOS_HAVE_PHDF5) && defined(ADIOS_HAVE_MPI)
+#ifdef ADIOS_HAVE_HDF5
         return std::make_shared<HDF5Writer>(*this, name, accessMode, mpiComm,
                                             method);
 #else

source/CMakeLists.txt

@@ -90,8 +90,10 @@ endif()
 
 if(ADIOS_USE_HDF5)
   find_package(HDF5 REQUIRED)
-  if(ADIOS_USE_MPI AND NOT HDF5_IS_PARALLEL)
-    message(FATAL_ERROR "A sequential version of HDF5 was detected but the parallel version of ADIOS requires a parallel HDF5.")
+  if(ADIOS_USE_MPI AND (NOT HDF5_IS_PARALLEL))
+    message(FATAL_ERROR "A sequential version of HDF5 was detected but the parallel version of ADIOS is being built, which requires a parallel HDF5.")
+  elseif((NOT ADIOS_USE_MPI) AND HDF5_IS_PARALLEL)
+    message(FATAL_ERROR "A parallel version of HDF5 was detected but the sequential version of ADIOS is being built, which requires a sequential HDF5.")
   endif()
 
   target_include_directories(adios2 PRIVATE ${HDF5_INCLUDE_DIRS})

source/engine/hdf5/HDF5WriterP.cpp

@@ -78,7 +78,9 @@ void HDF5Writer::Init()
 
     _plist_id = H5Pcreate(H5P_FILE_ACCESS);
 
+#ifdef ADIOS_HAVE_MPI
     H5Pset_fapl_mpio(_plist_id, m_MPIComm, MPI_INFO_NULL);
+#endif
 
     /*
      * Create a new file collectively and release property list identifier.
@@ -340,8 +342,9 @@ void HDF5Writer::UseHDFWrite(Variable<T> &variable, const T *values,
     //  Create property list for collective dataset write.
 
     _plist_id = H5Pcreate(H5P_DATASET_XFER);
+#ifdef ADIOS_HAVE_MPI
     H5Pset_dxpl_mpio(_plist_id, H5FD_MPIO_COLLECTIVE);
-
+#endif
     herr_t status;
 
     status =