Re: fatal errors for missing include files.

[Ian Dunbar]

Hi Paul,

Thanks for the clarification. I have still some questions though.

> From: "Paul D. Smith" <address@hidden>
>
>   id> It would know that the order of making up to date has to be:
>   id> Makefile, sub.mk, subsub.mk, subsubsub.mk, etc., because if sub.mk
>   id> is out of date, there is no guarentee that the soon to be updated
>   id> version will include the same files as before.
>
> Ah.  There is an even deeper misunderstanding here.
>
> Note that when remaking makefiles, make does _NOT_ proceed like this:

Ok, but I am surprised you don't you see any problem (bug) with the current 
way?

> This doesn't matter though: remaking sub.mk in no way changes the rules,
> variables, etc. that make knows about because the makefile is not
> re-read immediately after it's created.  So, if there were no rules to
> build that target before sub.mk was rebuilt, there cannot be any
> afterwards either.

I don't really understand why does adding the order only-prerequsite like 
this solve the problem, if make truly does not re-read the makefiles between 
remaking them?

subsub.mk: | sub.mk
include subsub.mk

> From my understanding, all that says is that you should build sub.mk before 
subsub.mk. By your rule of rebuilding everything first, make should still 
attempt and fail (fatally because we are past the no-fatal-errors stage 
mentioned previously) to make subsub.mk. However, it gives the same warning 
for "subsub.mk", but this time it's non-fatal.

Original way:
sub.mk:1: subsub.mk: No such file or directory
make: *** No rule to make target `subsub.mk'.  Stop.

With order-only:
sub.mk:2: subsub.mk: No such file or directory
cp sub.prj sub.mk
make: Nothing to be done for `default'.

Why is this? In both ways, sub.mk is out of date, and subsub.mk can't be 
made?

Best regards,
Ian

_________________________________________________________________
Add photos to your messages with MSN 8. Get 2 months FREE*. 
http://join.msn.com/?page=features/featuredemail