Make detecting of HIP dependencies more user friendly

cmake/cudawrappers-dependencies.cmake

@@ -1,4 +1,53 @@
 if(${CUDAWRAPPERS_BACKEND_HIP})
+  # cmake-format: off
+  # This following code attempts to locate the HIP runtime library's root directory.
+  #
+  # 1. Checks if the ROCM_ROOT and ROCM_PATH variables are defined.
+  #    - Assign them from corresponding environment variables if not defined.
+  # 2. Searches for the HIP runtime header file in the paths specified by ROCM_ROOT and ROCM_PATH.
+  #    - If the path is set but HIP is not found, an error message is generated.
+  # 3. If HIP is still not found, the script searches in the default path.
+  # 4. Adding HIP_ROOT_DIR to CMAKE_PREFIX_PATH and Finding Packages
+  #    - The HIP runtime directory (HIP_ROOT_DIR) is appended to CMAKE_PREFIX_PATH
+  #      to ensure that CMake can find the HIP-related packages.
+  # 
+  # Usage:
+  # Set the ROCM_ROOT or ROCM_PATH environment variables or pass them as CMake options, e.g.:
+  #   cmake -DROCM_ROOT=/path/to/rocm ..
+  #   or
+  #   ROCM_ROOT=/path/to/rocm cmake ..
+  # cmake-format: on
+
+  foreach(var IN ITEMS ROCM_ROOT ROCM_PATH)
+    # Step 1.
+    if(NOT DEFINED ${var})
+      set(${var} $ENV{${var}})
+    endif()
+
+    # Step 2.
+    find_path(
+      HIP_ROOT_DIR
+      NAMES include/hip/hip_runtime.h
+      PATHS ${${var}}
+      NO_DEFAULT_PATH
+    )
+
+    if(NOT HIP_ROOT_DIR AND ${var})
+      message(FATAL_ERROR "HIP not found in " ${${var}})
+    endif()
+  endforeach()
+
+  if(NOT HIP_ROOT_DIR)
+    # Step 3.
+    find_path(
+      HIP_ROOT_DIR
+      NAMES include/hip/hip_runtime.h
+      PATHS /opt/rocm
+    )
+  endif()
+
+  # Step 4.
+  list(APPEND CMAKE_PREFIX_PATH ${HIP_ROOT_DIR})
   find_package(hip REQUIRED)
   find_package(hipfft REQUIRED)
 else()