Re: directory search fails!

[Paul Smith]

On Wed, 2010-09-22 at 13:41 +0200, Eli Zaretskii wrote:
> > From: Paul Smith <address@hidden>
> > Cc: ali hagigat <address@hidden>, address@hidden
> > Date: Wed, 22 Sep 2010 07:06:12 -0400
> > 
> > > This means that if the Makefile uses a target named "target1", which
> > > is found by directory search at /foo/bar/baz/target1, then Make will
> > > use "/foo/bar/baz/target1" in all places where the Makefile mentions
> > > "target1".  At least this is my understanding of the manual's text.
> > 
> > No, not "in all places where the Makefile mentions" it.
> > 
> > Only in places where make supplies the name; in particular expansions of
> > automatic variables like $< etc.
> > 
> > Make does not go through the recipes, etc. and replace "target1" with
> > "/foo/bar/baz/target1".
> 
> But, since the same directory search will find "target1" in the same
> place over and over again, the net effect is indistinguishable, right?

I don't follow you.  A simple example will show what I mean:

        vpath xyzzy somedir

        all: xyzzy
                @echo $<
                @echo xyzzy

Assuming that ./xyzzy does not exist and ./somedir/xyzzy does exist,
then this will print:

        somedir/xyzzy
        xyzzy

It will NOT print:

        somedir/xyzzy
        somedir/xyzzy

Make remembers the vpath-found name internally and uses that name
wherever it is asked what the name is (for example when expanding
automatic variables like $<).

It will NOT do some textual search/replace on the contents of the recipe
and change every string matching the original target name to the new
name.

-- 
-------------------------------------------------------------------------------
 Paul D. Smith <address@hidden>          Find some GNU make tips at:
 http://www.gnu.org                      http://make.mad-scientist.net
 "Please remain calm...I may be mad, but I am a professional." --Mad Scientist