Re: How to refer to the first target?

[Eli Zaretskii]

> Date: Thu, 26 Nov 2009 07:42:33 -0600
> From: Peng Yu <address@hidden>
> 
> >        a: command.sh
> >                ./command.sh
> >        b: command.sh
> >                ./command.sh
> >
> > So, in this case, there is only one target file each time command.sh is
> > invoked, and the name of that target will be stored in address@hidden  So 
> > the first
> > time command.sh is invoked, $@ will be set to "a" and the second time it
> > will be set to "b".
> 
> I don't understand the following case. If there are two rules, why
> command.sh is only executed once.
> 
> $ touch command.sh
> $ make
> ./command.sh

Because by default, Make only builds the first target in the Makefile,
in this case a.  Try this, and you should see 2 invocations of
command.sh:

 $ touch command.sh
 $ make a b

> If there are multiple files that are generated by command.sh, are you
> suggesting to write a single rule for an arbitrarily chosen single
> file? But if I only have a rule for 'a' but not for 'b', when the file
> 'b' is deleted, 'command.sh' will not called by make. But I do want
> make to updated 'b'. How do you deal with this case?

The only way AFAIK is to use static pattern rules, and come up with a
pattern that will catch both a and b, but nothing else.