"Deleted header file" problem: aclocal.m4 deps

[Ralf Wildenhues]

The "deleted header file" problem that was solved for object file
dependency generation a long time ago also affects aclocal.m4
generation.  For a long time, this wasn't a problem, since the
list of local *.m4 files in a project was rather stable.  The
dynamics of gnulib changed this, and by gnulib's popularity,
| make: *** No rule to make target `../foo/m4/foobar.m4', needed by 
`../foo/Makefile.in'.  Stop.

followed by an explicit
  ./config.status --recheck && ./config.status && make

has become somewhat more common.

The patch below takes a very simple-minded approach at a fix.  Do you
think that is too broad?  If we can find a better criterion, maybe we
can factor $(am__configure_deps) based on that?  Or do you think this
is anyway too dangerous?

Cheers,
Ralf

        * lib/am/configure.am (%?REGEN-ACLOCAL-M4%): New target
        $(am__aclocal_m4_deps) without any dependencies, to avoid the
        "deleted .m4 file" problem.
        * tests/acloca22.test: New test.
        * tests/Makefile.am: Update.

Index: lib/am/configure.am
===================================================================
RCS file: /cvs/automake/automake/lib/am/configure.am,v
retrieving revision 1.31
diff -u -r1.31 configure.am
--- lib/am/configure.am 14 May 2005 20:28:52 -0000      1.31
+++ lib/am/configure.am 17 Sep 2006 18:10:56 -0000
@@ -113,7 +113,10 @@
 ## aclocal.m4 too.  Changing configure.ac, or any file included by
 ## aclocal.m4 might require adding more files to aclocal.m4.  Hence
 ## the $(am__configure_deps) dependency.
+##
+## Avoid the "deleted header file" problem for the dependencies.
 if %?REGEN-ACLOCAL-M4%
+$(am__aclocal_m4_deps):
 $(ACLOCAL_M4): %MAINTAINER-MODE% $(am__aclocal_m4_deps)
 ?TOPDIR_P?     cd $(srcdir) && $(ACLOCAL) $(ACLOCAL_AMFLAGS)
 ?!TOPDIR_P?    cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh
Index: tests/Makefile.am
===================================================================
RCS file: /cvs/automake/automake/tests/Makefile.am,v
retrieving revision 1.609
diff -u -r1.609 Makefile.am
--- tests/Makefile.am   30 Aug 2006 20:35:56 -0000      1.609
+++ tests/Makefile.am   17 Sep 2006 18:10:57 -0000
@@ -24,6 +24,7 @@
 acloca19.test \
 acloca20.test \
 acloca21.test \
+acloca22.test \
 acoutnoq.test \
 acoutpt.test \
 acoutpt2.test \
--- /dev/null   2006-09-17 19:23:11.320383500 +0200
+++ tests/acloca22.test 2006-09-17 19:59:41.000000000 +0200
@@ -0,0 +1,44 @@
+#! /bin/sh
+# Copyright (C) 2006  Free Software Foundation, Inc.
+#
+# This file is part of GNU Automake.
+#
+# GNU Automake is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# GNU Automake is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Automake; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+# Boston, MA 02110-1301, USA.
+
+# Make sure the "deleted header file" issue is fixed wrt. aclocal.m4
+# dependencies.
+
+. ./defs || exit 1
+
+set -e
+
+cat >>configure.in <<EOF
+FOO
+AC_OUTPUT
+EOF
+cat >foo.m4 <<EOF
+AC_DEFUN([FOO], [:])
+EOF
+: >Makefile.am
+$ACLOCAL -I .
+$AUTOMAKE
+$AUTOCONF
+./configure
+$MAKE
+sed '/FOO/d' < configure.in > t
+mv -f t configure.in
+rm -f foo.m4
+$MAKE