Applying the whole RPATH treatment

CMakeLists.txt

@@ -25,8 +25,35 @@ if(NOT CMAKE_CXX_STANDARD MATCHES "14|17")
   message(FATAL_ERROR "Unsupported C++ standard: ${CMAKE_CXX_STANDARD}")
 endif()
 
-# Setting RPATH ------------------------------------------------
-set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
+#---RPATH options-------------------------------------------------------------------------------
+option(K4FWCORE_SET_RPATH         "Link libraries with built-in RPATH (run-time search path)" ON)
+
+#  When building, don't use the install RPATH already (but later on when installing)
+set(CMAKE_SKIP_BUILD_RPATH FALSE)           # don't skip the full RPATH for the build tree
+set(CMAKE_BUILD_WITH_INSTALL_RPATH FALSE)   # use always the build RPATH for the build tree
+set(CMAKE_MACOSX_RPATH TRUE)                # use RPATH for MacOSX
+set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE) # point to directories outside the build tree to the install RPATH
+
+# Check whether to add RPATH to the installation (the build tree always has the RPATH enabled)
+if(APPLE)
+  set(CMAKE_INSTALL_NAME_DIR "@rpath")
+  set(CMAKE_INSTALL_RPATH "@loader_path/../lib")    # self relative LIBDIR
+  # the RPATH to be used when installing, but only if it's not a system directory
+  list(FIND CMAKE_PLATFORM_IMPLICIT_LINK_DIRECTORIES "${CMAKE_INSTALL_PREFIX}/lib" isSystemDir)
+  if("${isSystemDir}" STREQUAL "-1")
+    set(CMAKE_INSTALL_RPATH "@loader_path/../lib")
+  endif("${isSystemDir}" STREQUAL "-1")
+elseif(K4FWCORE_SET_RPATH)
+  set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib") # install LIBDIR
+  # the RPATH to be used when installing, but only if it's not a system directory
+  list(FIND CMAKE_PLATFORM_IMPLICIT_LINK_DIRECTORIES "${CMAKE_INSTALL_PREFIX}/lib" isSystemDir)
+  if("${isSystemDir}" STREQUAL "-1")
+    set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")
+  endif("${isSystemDir}" STREQUAL "-1")
+else()
+  set(CMAKE_SKIP_INSTALL_RPATH TRUE)           # skip the full RPATH for the install tree
+endif()
+
 
 add_subdirectory(k4FWCore)
 add_subdirectory(k4Interface)