On Thu, 01 Nov 2012, Alan Barrett wrote:
I generalised that idea. The appended patch adds a "params" file in the top-level obj directory, containing all the setting that might affect the build, defines the variable _NETBSD_VERSION_DEPENDENT in <bsd.own.mk>, and uses ${_NETBSD_VERSION_DEPENDENT} as a dependency for a few files that must be re-generated when the NetBSD version changes, and that should possibly be re-generated when certain build settings are changed.
I have committed this change, with _NETBSD_VERSION_DEPENDENT renamed to _NETBSD_VERSION_DEPENDS. --apb (Alan Barrett)