On Thu, 2011-01-13 at 12:50 -0600, Bob Friesenhahn wrote: > FYI, ClearCase's clearmake is actually based on GNU make source code. > At least it was back when I was using it.
Not that it matters but this is not _quite_ true... otherwise clearmake would fall under the GPL. What clearmake used to do was ship with a patched version of GNU make that added a -E flag, when that flag was given then GNU make would read the makefiles but instead of actually building anything it would output an "elaborated" makefile with much of the extra functionality of GNU make already expanded; for example ifdef etc. would be processed already, etc. Clearmake in GNU make mode would exec that patched version of GNU make with the -E flag, then read the output to get a more vanilla makefile. This gave some limited support for GNU make syntax. However, that model was ditched back in the 1990's sometime. The last time I used ClearCase (over 4 years ago now), clearmake simply implemented some set of GNU make features natively without using any GNU make preprocessor. However, the set of features implemented was pretty weak; something like GNU make 3.76 or so; not much beyond that. And, even some 3.76 features there were missing, like auto re-exec capabilities etc.