Hi Stefano,
> 'AM_IGNORE_UNDEFINED_CONDITIONALS' can accept two
> arguments, "yes" and "no" (defaulting to "yes" if no argument is given).
> The idea is that an usage like:
>
> AM_CONDITIONAL([FOO], [:])
> AM_IGNORE_UNDEFINED_CONDITIONALS([yes])
> if test -n "$user_flag"; then
> AM_CONDITIONAL([BAR], [test $user_flag = yes])
> fi
> AM_IGNORE_UNDEFINED_CONDITIONALS([no])
> if test 1 = 1; then
> AM_CONDITIONAL([BAZ], [:])
> fi
>
> will cause the generated configure to check that the FOO and BAZ
> conditionals are defined, but not to check that the BAR conditional
> is defined.
This would fit gnulib's use-case. Thank you.
Actually this pair of AM_IGNORE_UNDEFINED_CONDITIONALS invocations looks
like something that should be nestable:
AM_IGNORE_UNDEFINED_CONDITIONALS([yes])
if test $enable_foo; then
AM_CONDITIONAL([FOO], [:])
fi
AM_IGNORE_UNDEFINED_CONDITIONALS([yes])
if test -n "$user_flag"; then
AM_CONDITIONAL([BAR], [test $user_flag = yes])
fi
AM_IGNORE_UNDEFINED_CONDITIONALS([no])
if test 0 = 1; then
AM_CONDITIONAL([BAZ], [:])
fi
AM_IGNORE_UNDEFINED_CONDITIONALS([no])
should cause the generated configure to not check about FOO, BAR, BAZ.
Since the usual way to implement nestable behaviour in Autoconf is
m4_pushdef / m4_popdef, maybe it is sufficient to document a single
m4_define'd macro, say, AM_CHECK_CONDITIONALS_DEFINED, so that the
snippet above can be written as:
m4_pushdef([AM_CHECK_CONDITIONALS_DEFINED], [])
if test $enable_foo; then
AM_CONDITIONAL([FOO], [:])
fi
m4_pushdef([AM_CHECK_CONDITIONALS_DEFINED], [])
if test -n "$user_flag"; then
AM_CONDITIONAL([BAR], [test $user_flag = yes])
fi
m4_popdef([AM_CHECK_CONDITIONALS_DEFINED])
if test 0 = 1; then
AM_CONDITIONAL([BAZ], [:])
fi
m4_popdef([AM_CHECK_CONDITIONALS_DEFINED])
Bruno
--
In memoriam Lamana Ould Bou <http://fr.wikipedia.org/wiki/Lamana_Ould_Bou>
