Re: configuring sub directories optional

[Eric Siegerman]

On Mon, Oct 28, 2002 at 01:04:44PM -0500, Jeff Squyres wrote:
> When you us AC_CONFIG_SUBDIRS, foo/configure is run *after* the main
> configure script completes (I don't know the exact mojo, but its
> definitely run either after or at the end of my top-level configure.ac's
> AC_OUTPUT). [...]
> 
> So there's no chance for the top-level configure.ac to analyze and react
> if foo/configure fails.

I guess the ideal solution would be something like
        AC_CONFIG_SUBDIRS(dirs [, is_optional_flag])
which somehow provides status to the caller if is_optional_flag
is set.

Hmm, how about this, which is also the usual Autoconf approach:
        AC_CONFIG_SUBDIRS(dirs, [action-if-succeeds], [action-if-fails])
with the default actions being the current behaviour:
  - action-if-succeeds defaults to "do nothing"
  - action-if-fails defaults to "abort"
Or any other wrinkles necessary to stay backward compatible.

Of course, this would require moving the "CONFIG_SUBDIRS section"
to an earlier point in the configure script, to give the parent
configure.ac a chance to do something useful with the returned
status.

Actually, just moving the CONFIG_SUBDIRS section, without any API
changes, would permit a kludgy solution:
  - an optional subpackage could use a configure.gnu shell-script
    wrapper to lie about the sub-configure's exit status:
        #! /bin/sh
        $CONFIG_SHELL ./configure ${1+"$@"}
        exit 0

  - the parent configure.ac could check for the existence of some
    generated file in the subdirectory, as someone else suggested

--

|  | /\
|-_|/  >   Eric Siegerman, Toronto, Ont.        address@hidden
|  |  /
The acronym for "the powers that be" differs by only one letter
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