Re: Advanced Auto-Dependency Generation

[Greg Kilfoyle]

All objects and dependency files are in a separate directory hierarchy
which mirrors the source hierarchy.

As I mentioned in my other reply, I'm still not sure if I'll do anything
further to protect against this.

Thanks, Greg.


On Tue, 2005-04-12 at 10:50, Noel Yap wrote:
> IMHO, dependency files, as with other generated files, ought to be built in a 
> directory structure separate from the source directories.  If this were done, 
> one /would/ protect against _accidental_ erasure of the dependency files (no 
> mortal should be 
> meddling in the build directories).
> 
> HTH,
> Noel
> 
> Greg Kilfoyle wrote:
> 
> > Hi,
> > 
> > I have implemented dependency generation based on the information from
> > this web page: http://make.paulandlesley.org/autodep.html
> > 
> > It works great, but my implementation has one serious drawback that I
> > don't see covered ... maybe I just missed something.
> > 
> > Let's say I have just done a complete build and everything is up-to-
> > date. I then manually remove a dependency file for a particular .c file
> > and update a header file that the .c file is dependent on. If I then run
> > make, the .c file is not rebuilt.
> > 
> > I had a depclean target in our environment, which I removed because of
> > this problem. But I can't protect against someone 'accidently' removing
> > a dependency file.
> > 
> > The following is a brief version of our .c->.o rule:
> > 
> > $(objs): $(objdir)/%.o: $(srcdir)/%.c
> >         gcc -c -MP -MD,$(basename $@).d -MT,'$@ $(basename $@).d'
> >             -o $@ $<
> > 
> > ...after this rule there is an include of the dependency file(s) using
> > '-' so it can silently fail.
> > 
> > Is this something I've failed to account for in my implementation or
> > something that is missing from the proposed implementation method?
> > 
> > Cheers, Greg.
-- 
Greg Kilfoyle <address@hidden>