Re: Is there a way to insert a short pause?

[Richard Ash]

On Fri, 2009-10-16 at 09:27 +0200, Paolo Bonzini wrote:
> On 10/15/2009 08:29 PM, Ralf Wildenhues wrote:
> > That, on the other hand, sounds like an interesting idea.  We could
> > easily let configure print something like
> >    configure: WARNING: There have been warnings during this configure run.
> >
> > when it has come across a AC_MSG_WARNING.  WDYT?
Definitely useful. Could it come out along with AC_OUTPUT, so that
existing "last thing configure says" output (which is done as you
describe) doesn't get pushed away by warnings?

> Interesting indeed.  I see two things making this non-trivial though.
> 
> The first is that you want to be friendly to warning inside subshells. 
> This means you have to grep config.log for warnings and be careful about 
> false positives (or maybe "grep -F WARNING:" is enough?)
Can we anchor the pattern to it's place on the line, so if the
configure.ac writer puts WARNING somewhere in an info message it doesn't
cause a false positive. I was thinking of ^WARNING except the lines
start with file name and line number, something like

^configure: [0-9].: WARNING: 

might do it (until we find what grep is and isn't capable of on
different platforms).

> The second is how to handle AC_CONFIG_SUBDIRS.

I could live with "don't" or requiring configure.ac-writer intervention,
because this tends to cause spurious warnings if the sub-configure has
fewer options than top level (e.g. configure: WARNING: unrecognized
options: --with-wx-config, because I'm building 3rd-party sub-libraries
that don't need wxWidgets, but top level does, and needs the option to
find it's libraries).

In other words, I can think of significant other things to change round
AC_CONFIG_SUBDIRS, which might make it easier or harder to implement.

Richard