Create FindQMCKL module

cmake/FindQMCKL.cmake

@@ -0,0 +1,77 @@
+#===========================================
+
+# Try to find the QMCkl library;
+# If found, it will define the following variables (note the plural form):
+#  QMCKL_FOUND - System has libqmckl;
+#  QMCKL_INCLUDE_DIRS - The QMCKL include directories;
+#  QMCKL_LIBRARIES - The libraries needed to use QMCKL;
+
+# If QMCKL has been installed in a non-standard location, one can set an 
+# environment variable $QMCKL_DIR in the current shell:
+# $ export QMCKL_DIR=<custom_path>
+# to indicate the prefix used during the QMCKL installation
+# (typically `./configure prefix=<custom_path> ..` or `cmake -DCMAKE_INSTALL_DIR=<custom_path> ..`)
+
+# This file should be located WITHIN your project source tree.
+# (e.g. in cmake/FindQMCKL.cmake)
+# How to use it in your project CMakeLists.txt:
+
+# This is needed to locate FindQMCKL.cmake file, modify it according to your source tree.
+# list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake/")
+
+# find_package(QMCKL)
+# if (QMCKL_FOUND)
+#   include_directories(${QMCKL_INCLUDE_DIRS})
+#   target_link_libraries(your_target ${QMCKL_LIBRARIES})
+# endif()
+
+#===========================================
+
+# This file is distirbuted under the BSD 3-Clause License.
+# Copyright (c) 2021, TREX Center of Excellence
+
+#===========================================
+
+message("<FindQMCKL.cmake>")
+
+set(QMCKL_SEARCH_PATHS
+	~/Library/Frameworks
+	/Library/Frameworks
+	/usr/local
+	/usr
+	/sw # Fink
+	/opt/local # DarwinPorts
+	/opt/csw # Blastwave
+	/opt
+)
+
+find_path(QMCKL_INCLUDE_DIR 
+	  NAMES qmckl.h 
+	  HINTS $ENV{QMCKL_DIR}
+	  PATH_SUFFIXES include/qmckl include
+	  PATHS ${QMCKL_SEARCH_PATHS}
+	  )
+	        
+
+# No need to specify platform-specific prefix (e.g. libqmckl on Unix) or
+# suffix (e.g. .so on Unix or .dylib on MacOS) in NAMES. CMake takes care of that.
+find_library(QMCKL_LIBRARY
+             NAMES qmckl
+	     HINTS $ENV{QMCKL_DIR}
+	     PATH_SUFFIXES lib64 lib
+	     PATHS ${QMCKL_SEARCH_PATHS}
+	     )
+
+message("<FindQMCKL.cmake>")
+
+# Handle the QUIETLY and REQUIRED arguments and set QMCKL_FOUND to TRUE if
+# all listed variables are TRUE.
+INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(QMCKL DEFAULT_MSG QMCKL_LIBRARY QMCKL_INCLUDE_DIR )
+MARK_AS_ADVANCED(QMCKL_INCLUDE_DIR QMCKL_LIBRARY)
+
+# Mot setting _INCLUDE_DIR and _LIBRARIES is considered a bug, 
+# see https://gitlab.kitware.com/cmake/community/-/wikis/doc/tutorials/How-To-Find-Libraries
+set(QMCKL_LIBRARIES ${QMCKL_LIBRARY})
+set(QMCKL_INCLUDE_DIRS ${QMCKL_INCLUDE_DIR}) 
+