recursion: support user-defined recursive targets

The user can now define his own recursive targets that recurse
in the directories specified in $(SUBDIRS).  That can be done by
specifying the name of such targets in invocations of the new
'AM_EXTRA_RECURSIVE_TARGETS' m4 macro.

The API goes like this:

    $ cat configure.ac
    AC_INIT([pkg-name], [1.0]
    AM_INIT_AUTOMAKE
    AM_EXTRA_RECURSIVE_TARGETS([foo])
    AC_CONFIG_FILES([Makefile sub/Makefile])
    AC_OUTPUT

    $ cat Makefile.am
    SUBDIRS = sub
    foo-local:
        @echo This will be run by "make foo".

    $ cat sub/Makefile.am
    foo-local:
        @echo This too will be run by a "make foo" issued either in
        @echo the 'sub/' directory or in the top-level directory.

Like for the "default" recursive targets (e.g., 'all' and 'check'),
the user-defined recursive targets descend in the $(SUBDIRS) in a
depth-first fashion, and process '.' last (unless that is explicitly
specified in $(SUBDIRS)).

* NEWS, doc/automake.texi: Document the new feature.
* automake.in (@extra_recursive_targets): New global variable.
(scan_autoconf_traces): Trace macro '_AM_EXTRA_RECURSIVE_TARGETS'.
(handle_user_recursion): New subroutine; among other things, it defines
the new internal '$(am__extra_recursive_targets)' make variable, and
the '*-am', '*-local' and '*-recursive' targets associated with the
user-specified user recursive targets.
(generate_makefile): Call the new subroutine.
* lib/am/subdirs.am (am__recursive_targets): New internal make variable,
listing all of '$(RECURSIVE_TARGETS)', '$(RECURSIVE_CLEAN_TARGETS)' and
'$(am__extra_recursive_targets)' together.
(AM_RECURSIVE_TARGETS): Adjust the definition of this variable ...
(.PHONY, .MAKE): ... and the list of dependencies of these special targets
to take advantage of the new '$(am__recursive_targets)' variable.
($(am__recursive_targets)): New targets, superseding ...
($(RECURSIVE_TARGETS), $(RECURSIVE_CLEAN_TARGETS)): ... these, and
inheriting their rules.  This way, the rules to handle recursion for
built-in recursive targets (e.g., 'all', 'dvi', 'clean') and for user
defined recursive targets are the same.
* m4/extra-recurs.m4: New file, contain definition of new macro
'AM_EXTRA_RECURSIVE_TARGETS' and '_AM_EXTRA_RECURSIVE_TARGETS'.
These macros are basically dummy, only used for tracing by automake.
* m4/Makefile.am (dist_automake_ac_DATA): Update.
* t/recurs-user.sh: New test.
* t/recurs-user2.sh: Likewise.
* t/recurs-user-deeply-nested.sh: Likewise.
* t/recurs-user-indir.sh: Likewise.
* t/recurs-user-keep-going.sh: Likewise.
* t/recurs-user-many.sh: Likewise.
* t/recurs-user-no-subdirs.sh: Likewise.
* t/recurs-user-no-top-level.sh: Likewise.
* t/recurs-user-override.sh: Likewise.
* t/recurs-user-phony.sh: Likewise.
* t/recurs-user-wrap.sh: Likewise.
* t/remake-recurs-user.sh: Likewise.
* t/list-of-tests.mk: Update.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/t/recurs-user-no-subdirs.sh b/t/recurs-user-no-subdirs.sh
new file mode 100755
index 000000000..ed56d07f7
--- /dev/null
+++ b/t/recurs-user-no-subdirs.sh
@@ -0,0 +1,52 @@
+#! /bin/sh
+# Copyright (C) 2012 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
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Check that user recursion can be made to work even when $(SUBDIRS)
+# is empty or undefined.
+
+. ./defs || exit 1
+
+cat >> configure.ac <<'END'
+AM_EXTRA_RECURSIVE_TARGETS([foo])
+AC_OUTPUT
+END
+
+$ACLOCAL
+$AUTOCONF
+
+# First try with undefined $(SUBDIRS).
+cat > Makefile.am <<'END'
+all-local: foo
+foo-local:
+	: > bar
+MOSTLYCLEANFILES = bar
+END
+$AUTOMAKE
+./configure
+$MAKE foo
+test -f bar
+
+$MAKE distclean
+test ! -r bar # Sanity check.
+
+# Now try with empty but defined $(SUBDIRS).
+echo SUBDIRS = >> Makefile.am
+$AUTOMAKE
+./configure
+$MAKE foo
+test -f bar
+
+: