use of AC_DEFUN_ONCE

[Bruno Haible]

Hi Eric,

After your introduction of AC_DEFUN_ONCE in autoconf, the documentation says:

  either the macro must be declared with AC_DEFUN_ONCE (although
  this only helps in Autoconf 2.64 or newer), or all
  uses of that macro should be through AC_REQUIRE

We have the backported AC_DEFUN_ONCE also in 00gnulib.m4.

It looks like it would be possible to simplify your commit from 2009-01-21
now, like this. What do think?


--- m4/errno_h.m4.orig  2009-05-04 00:38:17.000000000 +0200
+++ m4/errno_h.m4       2009-05-04 00:29:42.000000000 +0200
@@ -4,7 +4,6 @@
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
 
-dnl This macro must pass through AC_REQUIRE (never directly invoke it).
 AC_DEFUN_ONCE([gl_HEADER_ERRNO_H],
 [
   AC_REQUIRE([AC_PROG_CC])
--- m4/multiarch.m4.orig        2009-05-04 00:38:17.000000000 +0200
+++ m4/multiarch.m4     2009-05-04 00:29:42.000000000 +0200
@@ -19,7 +19,6 @@
 # Detect this situation and set the macro AA_APPLE_UNIVERSAL_BUILD at the
 # beginning of config.h and set APPLE_UNIVERSAL_BUILD accordingly.
 
-dnl This macro must pass through AC_REQUIRE (never directly invoke it).
 AC_DEFUN_ONCE([gl_MULTIARCH],
 [
   dnl Code similar to autoconf-2.63 AC_C_BIGENDIAN.
--- modules/errno.orig  2009-05-04 00:38:17.000000000 +0200
+++ modules/errno       2009-05-04 00:29:42.000000000 +0200
@@ -9,7 +9,7 @@
 include_next
 
 configure.ac:
-AC_REQUIRE([gl_HEADER_ERRNO_H])
+gl_HEADER_ERRNO_H
 
 Makefile.am:
 BUILT_SOURCES += $(ERRNO_H)
--- modules/multiarch.orig      2009-05-04 00:38:17.000000000 +0200
+++ modules/multiarch   2009-05-04 00:29:42.000000000 +0200
@@ -7,7 +7,7 @@
 Depends-on:
 
 configure.ac:
-AC_REQUIRE([gl_MULTIARCH])
+gl_MULTIARCH
 
 Makefile.am: