From 45f473304f1a13b9909a3236d8d154316fe7eddf Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <bonzini@gnu.org>
Date: Fri, 10 Oct 2008 09:02:36 +0200
Subject: [PATCH] Add and document AS_INIT_GENERATED.

* lib/m4sugar/m4sh.m4 (AS_INIT_GENERATED): New.
* lib/autoconf/status.m4 (_AC_OUTPUT_CONFIG_STATUS): Use it.
* doc/autoconf.texi (Initialization macros): Document it.
---
 ChangeLog              |  7 +++++++
 doc/autoconf.texi      | 35 +++++++++++++++++++++++++++++++++++
 lib/autoconf/status.m4 |  6 +-----
 lib/m4sugar/m4sh.m4    | 11 +++++++++++
 4 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 418aff61..bd108add 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2008-10-13  Paolo Bonzini  <bonzini@gnu.org>
+
+	Add and document AS_INIT_GENERATED.
+	* lib/m4sugar/m4sh.m4 (AS_INIT_GENERATED): New.
+	* lib/autoconf/status.m4 (_AC_OUTPUT_CONFIG_STATUS): Use it.
+	* doc/autoconf.texi (Initialization macros): Document it.
+
 2008-10-13  Eric Blake  <ebb9@byu.net>
 
 	Use consistent shell function style.
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index d9d82aa7..ff81c2ec 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -11943,6 +11943,41 @@ generated from, and code to sanitize the environment for the rest of the
 script.  Finally, it changes the current diversion to @code{BODY}.
 @end defmac
 
+@defmac AS_INIT_GENERATED
+@asindex{INIT_GENERATED}
+Initialize the M4sh environment.  This macro emits again all the
+code that is generated by @code{AS_INIT}, including the expansion of
+@code{AS_BOURNE_COMPATIBLE} and @code{AS_SHELL_SANITIZE}.  It is meant
+to be used in a quoted here document when generating other shell scripts.
+
+Note that @code{AS_INIT_GENERATED} does not emit the entire prolog.
+In particular, a line containing @code{#!$SHELL} must have already been
+emitted to the child script; you should not use @code{#!/bin/sh}, or the
+child script will not use the more modern shell that the parent script
+might have detected.  Currently, the suggested idiom for writing a M4sh
+shell script from within another script is:
+
+@example
+m4_rename([AS_MESSAGE_LOG_FD], [save_AS_MESSAGE_LOG_FD])dnl
+cat > "@var{file}" <<__EOF__
+#! $SHELL
+# Generated by $as_me.
+# ...
+
+SHELL=\$@{CONFIG_SHELL-$SHELL@}
+__EOF__
+
+cat >>"@var{file}" <<\__EOF__
+AS_INIT_GENERATED
+# ...
+__EOF__
+m4_rename([save_AS_MESSAGE_LOG_FD], [AS_MESSAGE_LOG_FD])dnl
+@end example
+
+This, however, may change in the future as the M4sh interface is
+stabilized further.
+@end defmac
+
 @defmac AS_LINENO_PREPARE
 @asindex{LINENO_PREPARE}
 @evindex LINENO
diff --git a/lib/autoconf/status.m4 b/lib/autoconf/status.m4
index ddc5f47f..6d622b9e 100644
--- a/lib/autoconf/status.m4
+++ b/lib/autoconf/status.m4
@@ -1332,11 +1332,7 @@ SHELL=\${CONFIG_SHELL-$SHELL}
 _ACEOF
 
 cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
-AS_SHELL_SANITIZE
-dnl Watch out, this is directly the initializations, do not use
-dnl AS_PREPARE, otherwise you'd get it output in the initialization
-dnl of configure, not config.status.
-_AS_PREPARE
+AS_INIT_GENERATED
 exec AS_MESSAGE_FD>&1
 
 # Save the log message, to keep $[0] and so on meaningful, and to
diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4
index 2e6b2f2c..9c09dc01 100644
--- a/lib/m4sugar/m4sh.m4
+++ b/lib/m4sugar/m4sh.m4
@@ -1695,6 +1695,17 @@ m4_define([AS_VAR_POPDEF],
 ## ----------------- ##
 
 
+# AS_INIT_GENERATED
+# -----------------
+# Emit m4sh initialization code in a suitable form for a quoted
+# here document.  Does not emit the `#!' sequence, which should be
+# generated with `#! $SHELL'; see the manual or autoconf/status.m4
+# for more detail.
+m4_defun([AS_INIT_GENERATED],
+[m4_require([AS_PREPARE])dnl
+AS_SHELL_SANITIZE
+_AS_PREPARE])
+
 # AS_INIT
 # -------
 # Initialize m4sh.
-- 
2.11.4.GIT