build HDF5: simplify/improve checks

Author: scivision

scripts/CMakeLists.txt

@@ -1,4 +1,6 @@
 cmake_minimum_required(VERSION 3.20)
+# https://github.com/HDFGroup/hdf5/blob/develop/CMakeLists.txt
+
 project(HDF5_build
 LANGUAGES C Fortran
 )
@@ -7,48 +9,41 @@ option(hdf5_parallel "build HDF5 parallel MPI" on)
 option(zlib_legacy "use legacy zlib 1.x")
 
 # --- system checks
-if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
-  message(FATAL_ERROR "please specify where to install HDF5 under, like
-  cmake -B build -DCMAKE_INSTALL_PREFIX=~/mylibs")
-endif()
+file(MAKE_DIRECTORY ${CMAKE_INSTALL_PREFIX})
 
 list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
 
+if(hdf5_parallel)
+  if(NOT MPI_ROOT AND DEFINED ENV{MPI_ROOT})
+    set(MPI_ROOT $ENV{MPI_ROOT})
+  endif()
+
+  if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND MPI_ROOT)
+    set(ld_path $ENV{LD_LIBRARY_PATH})
+    cmake_path(CONVERT "${ld_path}" TO_CMAKE_PATH_LIST ld_path NORMALIZE)
+    cmake_path(CONVERT "${MPI_ROOT}" TO_CMAKE_PATH_LIST MPI_ROOT NORMALIZE)
 
-if(NOT MPI_ROOT AND DEFINED ENV{MPI_ROOT})
-  set(MPI_ROOT $ENV{MPI_ROOT})
-endif()
+    find_package(MPI COMPONENTS C REQUIRED)
 
-if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND MPI_ROOT)
-  set(ld_path $ENV{LD_LIBRARY_PATH})
-  cmake_path(CONVERT "${ld_path}" TO_CMAKE_PATH_LIST ld_path NORMALIZE)
-  cmake_path(CONVERT "${MPI_ROOT}" TO_CMAKE_PATH_LIST MPI_ROOT NORMALIZE)
+    include(${PROJECT_SOURCE_DIR}/../cmake/check_mpi.cmake)
+    check_mpi_version()
 
-  if(NOT "${ld_path}" MATCHES "${MPI_ROOT}/lib")
-    message(WARNING "${MPI_ROOT}/lib not found in LD_LIBRARY_PATH: $ENV{LD_LIBRARY_PATH}
-    HDF5 build may fail due to bugs in HDF5 package CMake scripts.
-    Fix this by adding to ~/.bashrc or similar:
-      export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:${MPI_ROOT}/lib")
+    list(GET MPI_C_LIBRARIES 0 mpi_lib)
+    cmake_path(GET mpi_lib PARENT_PATH mpi_libdir)
+
+    if(NOT "${ld_path}" MATCHES "${mpi_libdir}")
+      message(WARNING "${mpi_libdir} not found in LD_LIBRARY_PATH: $ENV{LD_LIBRARY_PATH}
+      HDF5 build may fail due to bugs in HDF5 package CMake scripts.
+      Fix this by adding to ~/.bashrc or similar:
+        export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:{mpi_libdir}")
+    endif()
   endif()
-endif()
+endif(hdf5_parallel)
 
 # HDF5 install fails to work (link) if prior HDF5 library is installed there
-find_library(_hdf5_libprior NAMES hdf5 PATHS ${CMAKE_INSTALL_PREFIX} PATH_SUFFIXES lib NO_DEFAULT_PATH NO_CACHE)
-find_path(_hdf5_incprior NAMES hdf5.h PATHS ${CMAKE_INSTALL_PREFIX} PATH_SUFFIXES include NO_DEFAULT_PATH NO_CACHE)
-find_program(_hdf5_binprior NAMES h5cc PATHS ${CMAKE_INSTALL_PREFIX} PATH_SUFFIXES bin NO_DEFAULT_PATH NO_CACHE)
-if(_hdf5_binprior)
-  cmake_path(GET _hdf5_binprior PARENT_PATH _hdf5_binprior)
-else()
-  set(_hdf5_binprior "")
-endif()
-if(_hdf5_libprior)
-  cmake_path(GET _hdf5_libprior PARENT_PATH _hdf5_libprior)
-endif()
-if(_hdf5_libprior OR _hdf5_incprior OR _hdf5_binprior)
-  message(FATAL_ERROR "HDF5 library already installed:
-  ${_hdf5_libprior}
-  ${_hdf5_incprior}
-  ${_hdf5_binprior}
+find_package(HDF5 CONFIG PATHS ${CMAKE_INSTALL_PREFIX} NO_DEFAULT_PATH QUIET)
+if(HDF5_FOUND)
+  message(FATAL_ERROR "HDF5 library already installed: ${HDF5_DIR}
   Please pick a new install location or completely remove the old HDF5 install directory.
   Otherwise, HDF5 will fail to link correctly with prior version and this version mixed.")
 endif()
@@ -58,12 +53,6 @@ file(READ ${CMAKE_CURRENT_SOURCE_DIR}/../cmake/libraries.json json)
 
 set_property(DIRECTORY PROPERTY EP_UPDATE_DISCONNECTED true)
 
-if(hdf5_parallel)
-  find_package(MPI COMPONENTS C REQUIRED)
-  include(${PROJECT_SOURCE_DIR}/../cmake/check_mpi.cmake)
-  check_mpi_version()
-endif()
-
 include(${PROJECT_SOURCE_DIR}/../cmake/hdf5.cmake)
 
 message(STATUS "Build / install HDF5 ${hdf5_tag} to ${CMAKE_INSTALL_PREFIX}")
@@ -74,3 +63,8 @@ include(FeatureSummary)
 add_feature_info(HDF5parallel hdf5_parallel "HDF5 MPI layer")
 
 feature_summary(WHAT ENABLED_FEATURES DISABLED_FEATURES)
+
+# --- auto-ignore build directory
+if(NOT EXISTS ${PROJECT_BINARY_DIR}/.gitignore)
+  file(WRITE ${PROJECT_BINARY_DIR}/.gitignore "*")
+endif()