Re: make dependency question

[Brendan J Simon]

Hi Gert-Jan,

Thanks for the reply.  I have a feeling this will not work, at least for 
my scenario.  I have a top level makefile which includes the 
sub-makefiles which includes submakefiles ..... (and so on). 
Effectively there is only ONE makefile after all the sub-makefiles have 
been 'included'.  I don't think that a VPATH setting can be used to find 
the right sub-makefile.

eg. I need:
build/foo/fred.o : src/foo/fred.c src/foo/module.mk
build/bar/bloggs.o : src/bar/bloggs.c src/bar/module.mk

Using VPATH as you suggest would mean that the one module.mk file would 
always be found before the other, therefore most targets would have a 
dependency on the wrong module.mk file.  Maybe I'm missing something ?

I have found another method to solve the problem but it is not generic 
enough.  It means editiing each module.mk file and explicitly listing it 
as dependency to the object files.  I thought I found a more generic 
solution using a combination of the foreach() and patsubst() functions, 
but unfortunately the foreach() function returns a single string so I 
ended up with something like:
   build/foo/fred.o : src/foo/fred.c src/foo/module.mk 
build/bar/bloggs.o : src/bar/bloggs.c src/bar/module.mk ...
which completely confused make.

Thanks again,
Brendan Simon.



Gert-Jan Paulissen wrote:

> Try
>
>
> build/%.o : src/%.c module.mk
>      $(CC) -o $@ $(CFLAGS) $<
>
> and set VPATH to the module.mk directories. Have a look at the manual for more 
> details.