Use standard GNU installation paths

Author: aradi

CMakeLists.txt

@@ -6,18 +6,8 @@ option(BUILD_SHARED_LIBS "Whether the library should be a shared one" FALSE)
 
 option(INSTALL_INCLUDE_FILES "Whether include / module files should be installed" TRUE)
 
-set(INSTALL_BIN_DIR "${CMAKE_INSTALL_PREFIX}/bin" CACHE PATH
-  "Installation directory for executables")
-
-set(INSTALL_LIB_DIR "${CMAKE_INSTALL_PREFIX}/lib" CACHE PATH
-  "Installation directory for libraries")
-
-set(INSTALL_MOD_DIR "${CMAKE_INSTALL_PREFIX}/include/dftd3" CACHE PATH
-  "Installation directory for Fortran module files")
-
-set(INSTALL_CMAKE_DIR "${CMAKE_INSTALL_PREFIX}/lib/cmake" CACHE PATH
-  "Installation directory for CMake package export files")
-
+set(INSTALL_MODDIR "dftd3/modfiles" CACHE PATH
+  "Installation directory for Fortran module files (within standard include folder)")
 
 add_subdirectory(lib)
 if(NOT LIBRARY_ONLY)

lib/CMakeLists.txt

@@ -13,14 +13,14 @@ set_target_properties(dftd3 PROPERTIES Fortran_MODULE_DIRECTORY ${includedir})
 
 target_include_directories(dftd3 PUBLIC
   $<BUILD_INTERFACE:${includedir}>
-  $<INSTALL_INTERFACE:${INSTALL_MOD_DIR}>)
+  $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}/${INSTALL_MODDIR}>)
 
 install(TARGETS dftd3
   EXPORT ${INSTALL_EXPORT_NAME}
-  ARCHIVE DESTINATION ${INSTALL_LIB_DIR}
-  LIBRARY DESTINATION ${INSTALL_LIB_DIR})
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
 if(INSTALL_INCLUDE_FILES)
-  install(DIRECTORY ${includedir}/ DESTINATION ${INSTALL_MOD_DIR})
+  install(DIRECTORY ${includedir}/ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${INSTALL_MODDIR})
 endif()
 

prg/CMakeLists.txt

@@ -9,4 +9,4 @@ target_link_libraries(dftd3_standalone dftd3)
 set_target_properties(dftd3_standalone PROPERTIES OUTPUT_NAME "dftd3")
 
 install(TARGETS dftd3_standalone
-  RUNTIME DESTINATION ${INSTALL_BIN_DIR})
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})