chore: remove trivial macro from CMakeLists

CMakeLists.txt

@@ -198,29 +198,15 @@ if (EXISTS "${CMAKE_SOURCE_DIR}/.git")
     endif ()
 endif ()
 
-# Helper macros for install settings
-macro (ppic_convert_to_relative_path _var)
-    # Make sure _var is a relative path
-    if (IS_ABSOLUTE "${${_var}}")
-        file (RELATIVE_PATH ${_var} "${CMAKE_INSTALL_PREFIX}" "${${_var}}")
-    endif ()
-endmacro ()
-
 # Install settings
 if (WIN32)
-    # FIXME: try to avoid install to a "bin" subfolder under windows...
-    #        when fixed, don't forget to update the CI config file...
-    set (BIN_INSTALL_DIR "") # seems useless, don't know why...
+    # TODO: try to avoid install to a "bin" subfolder under windows...
+    #       when fixed, don't forget to update the CI config file...
 elseif (UNIX)
     if (CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
         set(CMAKE_INSTALL_PREFIX /usr)
     endif ()
 
-    set (BIN_INSTALL_DIR "${CMAKE_INSTALL_BINDIR}") # relative, usually "bin"
-    ppic_convert_to_relative_path(BIN_INSTALL_DIR)
-    set (LIB_INSTALL_DIR "${CMAKE_INSTALL_LIBDIR}") # "lib" or "lib64"
-    ppic_convert_to_relative_path(LIB_INSTALL_DIR)
-
     # install icon
     install (
         FILES assets/icons/app-icon.svg
@@ -242,9 +228,9 @@ elseif (UNIX)
 endif()
 
 set (INSTALL_TARGETS_DEFAULT_ARGS
-    RUNTIME DESTINATION ${BIN_INSTALL_DIR}
-    LIBRARY DESTINATION ${LIB_INSTALL_DIR}
-    ARCHIVE DESTINATION ${LIB_INSTALL_DIR} COMPONENT Devel
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT Devel
 )
 
 install (