Re: "unparallelizing" a recursive make

[Mike Shal]

On 6/12/05, Darin Johnson <address@hidden> wrote:
> Which may be true.  But on cygwin and a fast computer, there is
> a noticeable start-up delay on one sub-directory where I used the
> non-recursive method.  If the entire project was done this way I
> could imagine a startup delay of a minute.  Maybe that's not so
> important, but I think it's nicer to the users to not have the delay.
> 
> (The sub-projects are pretty much independent of each other as well,
> and everything is layed out to be easy to convert to non-recursive
> approach if I needed to)

What size delay are you talking about for the single directory? Are
you using a/any/several $(shell) commands to get build parameters?
I've found that's one of the biggest slowdowns for a make - recursive
or non. (Though I have limited experience with Cygwin, if that's any
different)

Also, you seem to imply that by using a non-recursive make, that you
must always do a top-level build. This is not necessarily true - I
generally use a wrapper script that searches up the tree for where to
start the build, and passes in the directory of where the script was
launched. The non-recursive make can then build everything from the
top level, but only load the rules from the execution level (and its
subdirectories).

Of course, if you skip loading any information in this way you might
have an incomplete build. But, if your directories are as independent
as you say, you wouldn't lose any flexibility by using a non-recursive
make.

-Mike