Re: deferred evaulation of function calls

[Noel Yap]

I think there's still a difference.  With the ':=', the wildcard function is 
called only once at the point of assignment.  With the '=', it's called once 
per use although the call will be cheap, but not free, due to the cache.

Noel

Robert P. J. Day wrote:

> On Thu, 27 May 2004, Paul D. Smith wrote:
>
>
> > You are running into the directory cache.
> >
> > If you modify the contents of a directory "behind make's back" then
> > things like wildcard, etc. may not work properly since they operate on
> > the cached version not the real directory contents.
>
>
> ah, so what this tells me is that, if i want to match a wildcard pattern
> and i use the wildcard() function, there really is no effective difference
> if i do that at the top of my makefile with either of:
>
> files = $(wildcard *.o)
> files := $(wildcard *.o)
>
> if, as you say, it's the cached version that is used to evaluate these,
> then in that respect they really are equivalent for what i was doing with
> them.
>
> rday