Re: creating directories through dependency

[John Graham-Cumming]

Michal Nowikowski wrote:
> I have a problem of chicken-and-egg type. Makefile:
> ---
> BUILDDIR=build
>
> $(BUILDDIR):
>   mkdir -p $(BUILDDIR)
>
> $(objs):%.o:%.c $(BUILDDIR)
>   $(CC) -c $< -o $(BUILDDIR)/$@
> ---
>
> In this situation BUILDDIR is created before sources are compiled.
> But when everything is compiled and I re-run make it tries to recompile
> some source files because make claims that BUILDDIR is newer then
> some object files. It is like that because BUILDDIR had been changing when
> new object file were generated and put into it.
>
> How to solve this problem i.e. avoid recompiling files during subsequent
> make run?

I wrote an article for CM Crossroads all about directory creation in GNU 
Make.  You can read it here:

http://www.cmcrossroads.com/content/view/6936/120/

John.