Re: AC_ARG_ENABLE and checking for unrecognized switches

[Bob Friesenhahn]

On Fri, 15 Mar 2019, Kip Warner wrote:
> > https://www.gnu.org/software/autoconf/manual/autoconf-2.68/html_node/Option-Checking.html
> >
> > My reading is that there *is* checking by default, but it is turned
> > off if you have a subdir configure, but then can be turned back on
> > again by the user.
>
> Good eye, Tom. The only problem here is my configure.ac doesn't use a
> AC_CONFIG_SUBDIRS because there are no child configure.ac scripts to
> run, so by default that checking should have been enabled. It's
> possible I could be doing something wrong though.

A project can be made subordinate to another project without the 
author of the subordinate project being aware of it.  This is a very 
useful capability.  This capability is used by projects such as GCC.

The Autotools philosophy is to provide as much freedom as possible to 
the end user while working in a consistent way.  This would include 
the case where a project is created which builds several other 
projects.

Bob
--
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
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