[Plplot-devel] automatic dependencies

[<fu...@ga...>]

I've fixed the auto deps support for Linux + old GCC strains.  Sorry
about the flase start.

At this point, it is my belief that:

1) Platforms other than Linux should see no change to prior behavior.
   ie, stale deps stored in objs.in are used, provide the appearance
   of dependency support, but mask out of date dependencies, resulting
   in trouble for developers on those platforms.

2) Linux with old GCC should see substantially improved behavior.
   Dependencies are now maintained along with the .o's, so are always
   up to date.

3) Linux with GCC 3+ sees best in class automatic dependency support,
   with a single GCC invocation producing both the .o and the .d
   files. 

All core and driver C files are covered.  x??c.c demos are covered.
tutor.c is not covered, and all f77 and C++ files are not covered.  

demos.in should be reformulated to use GNU pattern rules more
aggressively, and search for a way to fold tutor into the mix.

Shouldn't be too hard to support C++ source files for gcc 2/3, but I
won't be satisfied unless the soln handles KCC too.

Need to decide how to deal with non-Linux systems.  The old objs.in
thing is so much inferior to automorphing deps that I'd be personally
tempted to just toss objs.in, but I don't know how to implement
autodeps for every platform supported by PLplot at this time.  What do
other developers think about dropping objs.in, and just taking the
position that if someone wants deps for <their favorite platform>
then they should contribute code to define the dependency generation
step in the new compilation paradigm for their os/compiler choice, and
we'll integrate it.   ???

-- 
Geoffrey Furnish         fu...@ga...