Allowing the option of CUDA memory space only if CUDA is enabled

CMakeLists.txt

@@ -225,7 +225,7 @@ endif()
 
 
 set(ADIOS2_CONFIG_OPTS
-    BP5 DataMan DataSpaces HDF5 HDF5_VOL MHS SST CUDA Fortran MPI Python Blosc Blosc2 BZip2 LIBPRESSIO MGARD PNG SZ ZFP DAOS IME O_DIRECT Sodium Catalyst SysVShMem ZeroMQ Profiling Endian_Reverse
+    BP5 DataMan DataSpaces HDF5 HDF5_VOL MHS SST CUDA Fortran MPI Python Blosc Blosc2 BZip2 LIBPRESSIO MGARD PNG SZ ZFP DAOS IME O_DIRECT Sodium Catalyst SysVShMem ZeroMQ Profiling Endian_Reverse GPU_Support
 )
 
 GenerateADIOSHeaderConfig(${ADIOS2_CONFIG_OPTS})

cmake/DetectOptions.cmake

@@ -193,6 +193,7 @@ endif()
 if(CMAKE_CUDA_COMPILER AND CUDAToolkit_FOUND)
   enable_language(CUDA)
   set(ADIOS2_HAVE_CUDA TRUE)
+  set(ADIOS2_HAVE_GPU_Support TRUE)
 endif()
 
 # Fortran

source/adios2/common/ADIOSTypes.h

@@ -35,9 +35,13 @@ namespace adios2
 /** Memory space for the user provided buffers */
 enum class MemorySpace
 {
+#ifdef ADIOS2_HAVE_GPU_SUPPORT
     Detect, ///< Detect the memory space automatically
-    Host,   ///< Host memory space (default)
-    CUDA    ///< CUDA memory spaces
+#endif
+    Host, ///< Host memory space
+#ifdef ADIOS2_HAVE_CUDA
+    CUDA ///< CUDA memory spaces
+#endif
 };
 
 /** Variable shape type identifier, assigned automatically from the signature of

source/adios2/core/VariableBase.cpp

@@ -50,13 +50,14 @@ size_t VariableBase::TotalSize() const noexcept
 
 MemorySpace VariableBase::DetectMemorySpace(const void *ptr)
 {
+#ifdef ADIOS2_HAVE_GPU_SUPPORT
     if (m_MemSpaceRequested != MemorySpace::Detect)
     {
         m_MemSpaceDetected = m_MemSpaceRequested;
         return m_MemSpaceRequested;
     }
+#endif
 
-    // if the user requested MemorySpace::Detect
 #ifdef ADIOS2_HAVE_CUDA
     cudaPointerAttributes attr;
     cudaPointerGetAttributes(&attr, ptr);
@@ -72,16 +73,21 @@ MemorySpace VariableBase::DetectMemorySpace(const void *ptr)
 
 MemorySpace VariableBase::GetMemorySpace(const void *ptr)
 {
+#ifdef ADIOS2_HAVE_GPU_SUPPORT
     if (m_MemSpaceDetected == MemorySpace::Detect)
         m_MemSpaceDetected = DetectMemorySpace(ptr);
     return m_MemSpaceDetected;
+#endif
+    return MemorySpace::Host;
 }
 
 void VariableBase::SetMemorySpace(const MemorySpace mem)
 {
     m_MemSpaceRequested = mem;
     // reset the detected memory space
+#ifdef ADIOS2_HAVE_GPU_SUPPORT
     m_MemSpaceDetected = MemorySpace::Detect;
+#endif
 }
 
 void VariableBase::SetShape(const adios2::Dims &shape)

source/adios2/core/VariableBase.h

@@ -51,12 +51,13 @@ class VariableBase
      *  VariableStruct -> from constructor sizeof(struct) */
     const size_t m_ElementSize;
     /* User requested memory space and the detected memory space */
-#ifdef ADIOS2_HAVE_CUDA
+#ifdef ADIOS2_HAVE_GPU_SUPPORT
     MemorySpace m_MemSpaceRequested = MemorySpace::Detect;
+    MemorySpace m_MemSpaceDetected = MemorySpace::Detect;
 #else
     MemorySpace m_MemSpaceRequested = MemorySpace::Host;
+    MemorySpace m_MemSpaceDetected = MemorySpace::Host;
 #endif
-    MemorySpace m_MemSpaceDetected = MemorySpace::Detect;
 
     ShapeID m_ShapeID = ShapeID::Unknown; ///< see shape types in ADIOSTypes.h
     size_t m_BlockID = 0; ///< current block ID for local variables, global = 0