docs: document m4_define_default

* doc/autoconf.texi (Conditional constructs) <m4_define_default>:
Document it, since gnulib wants to use it.
* NEWS: Mention this.

Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/ChangeLog b/ChangeLog
index 0be58095e0df69f6392dda3007d901c38eadf290..92132b32d607e939a8ae082fd9bca965a0ca8d7c 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2010-08-26  Eric Blake  <eblake@redhat.com>
 
+       docs: document m4_define_default
+       * doc/autoconf.texi (Conditional constructs) <m4_define_default>:
+       Document it, since gnulib wants to use it.
+       * NEWS: Mention this.
+
        autoconf: warn if AC_*_IFELSE lacks complete program
        * lib/autoconf/lang.m4 (AC_LANG_DEFINES_PROVIDED): New macro.
        (AC_LANG_SOURCE): Call it.

diff --git a/NEWS b/NEWS
index 9998ab7c5450d315bad6582d63f11a767a8d9fe8..6010e7bc7b53bd81236a2f022811f2222c6f68ee 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -15,6 +15,8 @@ GNU Autoconf NEWS - User visible changes.
    a compelling reason why you cannot use AC_LANG_SOURCE but must
    avoid the warning.
 
+** The macro m4_define_default is now documented.
+
 
 * Major changes in Autoconf 2.67 (2010-07-21) [stable]
   Released by Eric Blake, based on git versions 2.66.*.

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index cf0c0a1041e6979e7521546cdbfad8fbc0053691..996525acddf5752765f98e89a9382db2972d0855 100644 (file)
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -11786,6 +11786,12 @@ demo4([empty], [text])
 @end example
 @end defmac
 
+@defmac m4_define_default (@var{macro}, @ovar{default-definition})
+@msindex{define_default}
+If @var{macro} does not already have a definition, then define it to
+@var{default-definition}.
+@end defmac
+
 @defmac m4_ifblank (@var{cond}, @ovar{if-blank}, @ovar{if-text})
 @defmacx m4_ifnblank (@var{cond}, @ovar{if-text}, @ovar{if-blank})
 @msindex{ifblank}