Re: AC_CONFIG_SUBDIRS and subdirs

[Akim Demaille]

>>>>> "Ralf" == Ralf Corsepius <address@hidden> writes:

Ralf> Hmm. It is just inconsistent with handling of CONFIG_SUBDIRS at
Ralf> all other places I am aware about.

Ralf> autoreconf treats them conditionally, 

Of course: it has no enough choice.  Dynamic vs Static, Runtime
vs. Compile time.   Similarly you could say autoconf considers them
conditionally.

Ralf> _AC_OUTPUT_SUBDIRS does so, 

Nope, it does not, as it loops over the shell variable that
AC_CONFIG_SUBDIRS sets at runtime.

Ralf> the documentation does so, 

Arg, that is true :(

Ralf> it's just AC_CONFIG_SUBDIRS which doesn't.



Ralf> Well, I agree wrt. the restrictions which have been set upon
Ralf> AC_CONFIG_FILES with autoconf-2.5x, but it is not _consistent_
Ralf> with regard to handling of config-subdirs at other places of
Ralf> autoconf.

Ralf> But, config-subdirs have been documented to be
Ralf> optional. Therefore, I do not understand why AC_CONFIG_SUBDIRS
Ralf> should not treat them optional.

Agreed, one of them is bogus.  But the documentation is in a worse
situation as it is not self consistent:

    @defmac AC_CONFIG_SUBDIRS (@var{dir} @dots{})
    @acindex CONFIG_SUBDIRS
    @ovindex subdirs
    Make @code{AC_OUTPUT} run @command{configure} in each subdirectory
    @var{dir} in the given whitespace-separated list.  Each @var{dir} should
    be a literal, i.e., please do not use:
    
    @example
    if test "$package_foo_enabled" = yes; then
      $my_subdirs="$my_subdirs foo"
    fi
    AC_CONFIG_SUBDIRS($my_subdirs)
    @end example
    
    @noindent
    because this prevents @samp{./configure --help=recursive} from
    displaying the options of the package @code{foo}.  Rather, you should
    write:
    
    @example
    if test "$package_foo_enabled" = yes; then
      AC_CONFIG_SUBDIRS(foo)
    fi
    @end example
    

The last example emphasizes my point.



Ralf> Or to put it the other way round: Why should _AC_CONFIG_SUBDIRS,
Ralf> autoreconf etc. treat them optional if AC_CONFIG_SUBDIRS
Ralf> doesn't?

See above.