message: Attempts to initialize AXOM_DATA_DIR from submodule path when not provided by user
diff: # other Axom Project Developers. See the top-level COPYRIGHT file for details.
  #
  # SPDX-License-Identifier: (BSD-3-Clause)
  +#------------------------------------------------------------------------------
  +# Axom project
  +#------------------------------------------------------------------------------
  if (ENABLE_CUDA)
  cmake_minimum_required(VERSION 3.9)
  @@ -11,18 +14,16 @@ endif()
  message(STATUS "Using CMake version ${CMAKE_VERSION}")
  -################################
  -# Axom project
  -################################
  +
  project(axom LANGUAGES C CXX)
  if (ENABLE_FORTRAN)
  enable_language(Fortran)
  endif()
  -################################
  -# BLT
  -################################
  +#------------------------------------------------------------------------------
  +# Initialize BLT build system
  +#------------------------------------------------------------------------------
  if (DEFINED BLT_SOURCE_DIR)
  # Support having a shared BLT outside of the repository if given a BLT_SOURCE_DIR
  @@ -30,11 +31,11 @@ if (DEFINED BLT_SOURCE_DIR)
  message(FATAL_ERROR "Given BLT_SOURCE_DIR does not contain SetupBLT.cmake")
  endif()
  else()
  - # Use internal BLT if no BLT_SOURCE_DIR is given
  + # Use internal 'blt' submodule path if BLT_SOURCE_DIR not provided
  set(BLT_SOURCE_DIR "${PROJECT_SOURCE_DIR}/cmake/blt" CACHE PATH "")
  if (NOT EXISTS ${BLT_SOURCE_DIR}/SetupBLT.cmake)
  message(FATAL_ERROR
  - "The BLT is not present. "
  + "Cannot locate BLT. "
  "Either run the following two commands in your git repository: \n"
  " git submodule init\n"
  " git submodule update\n"
  @@ -48,53 +49,45 @@ endif()
  include(${BLT_SOURCE_DIR}/SetupBLT.cmake)
  -################################
  -# built-in cmake modules
  -################################
  -include(CMakeDependentOption)
  +#------------------------------------------------------------------------------
  +# Attempt to set Axom's data directory (used for Axom's tests and examples)
  +#------------------------------------------------------------------------------
  +if(NOT AXOM_DATA_DIR)
  + # Use internal 'axom_dir' submodule path if AXOM_DATA_DIR not provided
  + get_filename_component(_data_dir "${PROJECT_SOURCE_DIR}/../data" ABSOLUTE)
  + if(EXISTS ${_data_dir})
  + set(AXOM_DATA_DIR ${_data_dir} CACHE PATH "")
  + endif()
  +endif()
  -################################
  -# Include standard build system logic and options
  -################################
  +#------------------------------------------------------------------------------
  +# Include build system logic and options
  +#------------------------------------------------------------------------------
  +include(CMakeDependentOption)
  include(cmake/CMakeBasics.cmake)
  -################################
  +#------------------------------------------------------------------------------
  # Global includes for the Axom projects (restrict these as much as possible)
  -################################
  +#------------------------------------------------------------------------------
  include_directories(${CMAKE_BINARY_DIR}/include)
  include_directories(${PROJECT_SOURCE_DIR})
  -################################
  -# Add Thirdparty Builtin Libs
  -################################
  +#------------------------------------------------------------------------------
  +# Add source directories
  +#------------------------------------------------------------------------------
  add_subdirectory(thirdparty)
  -################################
  -# Add Axom source
  -################################
  include(cmake/AxomVersion.cmake)
  add_subdirectory(axom)
  -################################
  -# Adds directory for tools code
  -# that uses axom
  -################################
  add_subdirectory(tools)
  -
  -################################
  -# Adds directory for building
  -# examples
  -################################
  add_subdirectory(examples)
  -################################
  -# Add docs
  -################################
  if (AXOM_ENABLE_DOCS)
  add_subdirectory(docs)
  endif()
  -################################
  -# Create header of configuration options
  -################################s
  +#------------------------------------------------------------------------------
  +# Generate header file with configuration options
  +#------------------------------------------------------------------------------
  include(cmake/AxomConfig.cmake)
  