Re: AC_DEFUN_ONCE semantics

[Eric Blake]

Eric Blake <ebb9 <at> byu.net> writes:

> I've trimmed my original proposal down to two smaller patches; I'm inclined 
to 
> submit the first one today, but hold off on the second for another 72 hours 
in 
> case anyone can find a reason why AC_PROG_INSTALL or AC_PROG_MKDIR_P should 
be 
> expanded more than once.
> 
> $ git pull git://repo.or.cz/autoconf/ericb.git m4-require

I'm interpreting silence as consent, and pushing this:


From: Eric Blake <address@hidden>
Date: Wed, 28 Jan 2009 09:11:43 -0700
Subject: [PATCH] Use AC_DEFUN_ONCE for some one-shot AC_PROG macros.

* lib/autoconf/programs.m4 (AC_PROG_MKDIR_P): Switch to
AC_DEFUN_ONCE, since this is a one-shot macro.
(AC_PROG_INSTALL): Likewise.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog                |    7 +++++++
 lib/autoconf/programs.m4 |    7 ++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 3d1cea4..67b207c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2009-02-03  Eric Blake  <address@hidden>
 
+       Use AC_DEFUN_ONCE for some one-shot AC_PROG macros.
+       * lib/autoconf/programs.m4 (AC_PROG_MKDIR_P): Switch to
+       AC_DEFUN_ONCE, since this is a one-shot macro.
+       (AC_PROG_INSTALL): Likewise.
+
+2009-02-03  Eric Blake  <address@hidden>
+
        Mention that packagers should not pre-set CFLAGS.
        * doc/autoconf.texi (Preset Output Variables) <CFLAGS>: Copy
        advice given by automake on handling variables reserved by GNU
diff --git a/lib/autoconf/programs.m4 b/lib/autoconf/programs.m4
index 3f66ae3..d12c0ae 100644
--- a/lib/autoconf/programs.m4
+++ b/lib/autoconf/programs.m4
@@ -2,7 +2,8 @@
 # Checking for programs.
 
 # Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
-# 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+# 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software
+# Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -544,7 +545,7 @@ m4_ifval([$3],
 # ---------------
 AN_MAKEVAR([INSTALL], [AC_PROG_INSTALL])
 AN_PROGRAM([install], [AC_PROG_INSTALL])
-AC_DEFUN([AC_PROG_INSTALL],
+AC_DEFUN_ONCE([AC_PROG_INSTALL],
 [AC_REQUIRE([AC_CONFIG_AUX_DIR_DEFAULT])dnl
 AC_REQUIRE_AUX_FILE([install-sh])dnl
 # Find a good install program.  We prefer a C program (faster),
@@ -682,7 +683,7 @@ AC_SUBST(INSTALL_DATA)dnl
 # recognize any option.  It will interpret all options as
 # directories to create.
 AN_MAKEVAR([MKDIR_P], [AC_PROG_MKDIR_P])
-AC_DEFUN([AC_PROG_MKDIR_P],
+AC_DEFUN_ONCE([AC_PROG_MKDIR_P],
 [AC_REQUIRE([AC_CONFIG_AUX_DIR_DEFAULT])dnl
 AC_REQUIRE_AUX_FILE([install-sh])dnl
 AC_MSG_CHECKING([for a thread-safe mkdir -p])
-- 
1.6.0.4