Re: Append dependencies through variables

[Paul Smith]

On Sun, 2013-05-26 at 19:49 +0200, Riccardo Manfrin wrote:
> You are absolutely right, I actually had my includes *after* the "all:" 
> target, in order to have the make process find the "all" target before 
> the others.

If you're just doing this to ensure that "all:" is the first target
defined, there are other ways to do this.

> > Rule targets and prerequisites are expanded immediately when the
> > makefile is parsed, so changes to variables after they appear in targets
> > and prerequisites are not reflected there.
> Ok, so is there a way to force a prerequisite to be expanded *after* the 
> variable it is made of has been evaluated throughout the whole makefile?

No, not via standard make operations.

> I've been reading the documentation and aldready tried with 
> ".SECONDEXPANSION" but could not find the proper way to use it.

You can do it with secondexpansion, like this:

  .SECONDEXPANSION:
  all: $$(MAKE_DEPS_ALL)

Note that enabling SECONDEXPANSION inflicts a performance penalty on
make.  It's probably not overly noticeable, unless you have a very large
build system.