Package Cross_Reference Attributes

Default_Switches: list, indexed, case-insensitive index
Index is a language name. Value is a list of switches to be used when invoking gnatxref for a source of the language, if there is no applicable attribute Switches.
^Switches^Switches^: list, optional index, indexed, case-insensitive index, others allowed
Index is a source file name. Value is the list of switches to be used when invoking gnatxref for the source.