Experimental Physics and
Industrial Control System

Michael Davidsaver <[email protected]> · Thu, 28 Feb 2013 10:51:51 -0500

On 02/28/2013 09:57 AM, Benjamin Franksen wrote:

On Thursday, February 28, 2013 09:41:14 Michael Davidsaver wrote:

Makefiles are so much fun...

If you don't like creating marker files (which must be cleaned) you can

also do:

one two three: create_some_files.pl

     ./create_some_files.pl

three: two
two: one

This creates a dependency chain forcing sequential execution.

Yes, but...

(1) The script can be called more often than necessary:

I don't think this is the case as long as the command

'./create_some_files.pl' creates all three files (which I assume it what

you intended).

It is my understanding that the existence and timestamp of the target

file are checked immediately after all dependent rules have run, and not

when the dependency tree is computed. This is why these rules work when

with '-j1'.

(2) Getting the additional sequentializing dependencies right is harder and
the result less obvious.

I certainly can't argue with this.

Again, think of a generated list of many, many files
(in our case the script creates 692 targets).

Wow. I agree that what I describe would not scale to this. I've

typically used this for code generators which produce two or three

output files.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System