Re: Process target only if prerequisite was processed?

[Ken Smith]

On Thu, Nov 11, 2004 at 06:07:25PM -0800, Matt Perry wrote:
> Is there a way to tell make to only process a target if one or more of its 
> prerequisites was processed?  Let's say I have a make file like this fake 
> one here:
> 
> all: prereq1 prereq2
>       do something
> prereq1:
>       ...
> prereq2:
>       ...
> 
> In this case an action needs to be taken if either one of the 
> prerequisites were processed.  The "all" target doesn't generate a file.  
> It just runs a program.
> 
> -- 
> Matt Perry | matt at primefactor dot com

Hi Matt,

If prereq1 and prereq2 are files, then make will already do the right
thing for you.  Since you say "all" does not generate a file, you should
declare it phony as follows.

.PHONY: all

  Ken Smith