1 ## automake - create Makefile.in from Makefile.am
2 ## Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2003, 2004, 2005
3 ## Free Software Foundation, Inc.
5 ## This program is free software; you can redistribute it and/or modify
6 ## it under the terms of the GNU General Public License as published by
7 ## the Free Software Foundation; either version 2, or (at your option)
10 ## This program is distributed in the hope that it will be useful,
11 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 ## GNU General Public License for more details.
15 ## You should have received a copy of the GNU General Public License
16 ## along with this program; if not, write to the Free Software
17 ## Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 ## Explicitly look in srcdir for benefit of non-GNU makes.
24 ## Recover from removal of CONFIG_HEADER
25 @if test ! -f $@; then \
27 $(MAKE) $(AM_MAKEFLAGS) %STAMP%; \
31 %STAMP%: %CONFIG_H_DEPS% $(top_builddir)/config.status
33 cd $(top_builddir) && $(SHELL) ./config.status %CONFIG_H_PATH%
36 ## Only the first file of AC_CONFIG_HEADERS is assumed to be generated
39 %CONFIG_HIN%: %MAINTAINER-MODE% $(am__configure_deps) %FILES%
40 cd $(top_srcdir) && $(AUTOHEADER)
41 ## Whenever $(AUTOHEADER) has run, we must make sure that
42 ## ./config.status will rebuild config.h. The dependency from %STAMP%
43 ## on %CONFIG_H_DEPS% (which contains config.hin) is not enough to
46 ## There are some tricky cases where this rule will build a
47 ## config.hin which has the same timestamp as %STAMP%, in which case
48 ## ./config.status will not be rerun (meaning that users will use in
49 ## out-of-date config.h without knowing it). One situation where this
50 ## can occurs is the following:
51 ## 1. the user updates some configure dependency (let's say foo.m4)
53 ## 2. the rebuild rules detect that a foo.m4 has changed,
54 ## run aclocal, autoconf, automake, and then run ./config.status.
55 ## (Note that autoheader hasn't been called yet, so ./config.status
56 ## outputs a config.h from an obsolete config.hin.)
57 ## 3. Once Makefile has been regenerated, make continues, and
58 ## discover that config.h is a dependency of the `all' rule.
59 ## Because config.h depends on stamp-h1, stamp-h1 depends on
60 ## config.hin, and config.hin depends on aclocal.m4, make runs
61 ## autoheader to rebuild config.hin.
62 ## Now make ought to call ./config.status once again to rebuild
63 ## config.h from the new config.hin, but if you have a sufficiently
64 ## fast box, steps 2 and 3 will occur within the same second: the
65 ## config.h/stamp-h1 generated from the outdated config.hin will have
66 ## the same mtime as the new config.hin. Hence make will think that
67 ## config.h is up to date.
69 ## A solution is to erase %STAMP% here so that the %STAMP% rule
70 ## is always triggered after the this one.
72 ## Autoheader has the bad habit of not changing the timestamp if
73 ## config.hin is unchanged, which breaks Make targets. Since what
74 ## must not changed gratuitously is config.h, which is already handled
75 ## by config.status, there is no reason to make things complex for