Re: [PATCH v8 0/6] xen: systemd support

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 29/07/14 09:54, Ian Campbell wrote:
> On Mon, 2014-07-28 at 20:33 +0200, Luis R. Rodriguez wrote:
>>> Did you run autogen.sh?
>> Actually you should not need to, odd.
> Indeed, I did this on commit.
>
>> mcgrof@ergon ~/devel/xen (git::staging)$ rm -f config/Paths.mk
>> mcgrof@ergon ~/devel/xen (git::staging)$ ./configure | grep Paths
>> config.status: creating config/Paths.mk
>>
>> What do you see?
> Perhaps Andrew is running "cd tools ; ./configure"?
>
> In http://lists.xen.org/archives/html/xen-devel/2014-07/msg03156.html I
> posited that nobody would be doing that (even going so far to doubt that
> it worked) but if Andrew is doing it then clearly I was wrong and we
> will need to rethink the approach.

Oh - indeed I am; It certainly did use to work.  At some point in the
past, the outer ./configure was a small shell script which cd'd into
tools and ran ./configure, and I got into the habit of only ever running
./configure from the tools subdir.

>
> If we need to support direct invocation of "sub" configure then the only
> approach which comes to my mind is to generate per-subsystem Paths.mk,
> e.g. in each of the sub-configures do:
>         AC_CONFIG_FILES("../config/Tools-Paths.mk:../config/Paths.mk.in")
> along with the other stuff[0] and adjusting the Makefile to use it,
> substituting Tools as needed for other subsystems of course.

Hmm - I have mixed opinions about this.  On the one hand, it would be
nice for sub configures to work, but splitting Paths.mk like this seems
like a recipe for subtle issues.  Would it be possible for a sub
configure to detect its dependencies and request that the outer
./configure gets run?

~Andrew

>
> I think you will also need to -include rather than include so that make
> clean et al work on an unconfigured tree. There is existing logic in the
> all the (I think) right places to deal with non-clean targets needing
> configure to have been run.
>
> BTW, I noticed the opposite problem to Andrew, which is that Paths.mk is
> not removed by "make clean".
>
> Ian.
>
> [0]
> https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.69/html_node/Configuration-Files.html says that the : syntax lets you override the input.
>