1# $Id: auto.obj.mk,v 1.8 2011/08/08 17:35:20 sjg Exp $
2#
3#	@(#) Copyright (c) 2004, Simon J. Gerraty
4#
5#	This file is provided in the hope that it will
6#	be of use.  There is absolutely NO WARRANTY.
7#	Permission to copy, redistribute or otherwise
8#	use this file is hereby granted provided that 
9#	the above copyright notice and this notice are
10#	left intact. 
11#      
12#	Please send copies of changes and bug-fixes to:
13#	sjg@crufty.net
14#
15
16ECHO_TRACE ?= echo
17
18.ifndef Mkdirs
19# A race condition in some versions of mkdir, means that it can bail 
20# if another process made a dir that mkdir expected to.
21# We repeat the mkdir -p a number of times to try and work around this.
22# We stop looping as soon as the dir exists.
23# If we get to the end of the loop, a plain mkdir will issue an error.
24Mkdirs= Mkdirs() { \
25	for d in $$*; do \
26		for i in 1 2 3 4 5 6; do \
27			mkdir -p $$d; \
28			test -d $$d && return 0; \
29		done > /dev/null 2>&1; \
30		mkdir $$d || exit $$?; \
31	done; }
32.endif
33
34# if MKOBJDIRS is set to auto (and NOOBJ isn't defined) do some magic...
35# This will automatically create objdirs as needed.
36# Skip it if we are just doing 'clean'.
37.if !defined(NOOBJ) && !defined(NO_OBJ) && ${MKOBJDIRS:Uno} == auto
38# Use __objdir here so it is easier to tweak without impacting
39# the logic.
40__objdir?= ${MAKEOBJDIR}
41.if ${.OBJDIR} != ${__objdir}
42# We need to chdir, make the directory if needed
43.if !exists(${__objdir}/) && \
44	(${.TARGETS} == "" || ${.TARGETS:Nclean*:N*clean:Ndestroy*} != "")
45# This will actually make it... 
46__objdir_made != echo ${__objdir}/; umask ${OBJDIR_UMASK:U002}; \
47        ${ECHO_TRACE} "[Creating objdir ${__objdir}...]" >&2; \
48        ${Mkdirs}; Mkdirs ${__objdir}
49.endif
50# This causes make to use the specified directory as .OBJDIR
51.OBJDIR: ${__objdir}
52.if ${.OBJDIR} != ${__objdir} && ${__objdir_made:Uno:M${__objdir}/*} != ""
53.error could not use ${__objdir}
54.endif
55.endif
56.endif
57