Re: non-recursive build question

[Noel Yap]

Paul D. Smith wrote:
> %% Noel Yap <address@hidden> writes:
>
>   ny> OTOH, you can have a different definition of "updated".  Order
>   ny> rules consider something "updated" iff that something exists.
>
> I'm not sure that this is quite true... maybe we're just have a
> terminology problem.
>
> Order-only rules don't care about "updated-ness" in any way.  All they
> do is enforce an order in which make will perform steps, without making
> any statement about dependencies.  If A has an order-only prerequisite
> B, then _IF_ B needs to be updated it will always be updated before A.
> Furthermore, the decision on whether to update A will not take any
> account of whether B had to be updated or not.

Yeah, I think we're saying the same thing but with different POV's.

From my POV, GNU make now has two ways to specify the conditions in which 
something is built due to one of its dependencies:
1. Normal dependencies: the LHS is built if the RHS's timestamp changes
2. Order dependencies: the LHS is built if the RHS didn't exist

IMHO, it'd be great (although I wouldn't know what type of syntax one could 
use) if one could define customized conditions (eg MD5 hash changes, version 
changes, ...).

Noel