# $Id: auto.obj.mk,v 1.12 2015/12/16 01:57:06 sjg Exp $
#
#	@(#) Copyright (c) 2004, Simon J. Gerraty
#
#	This file is provided in the hope that it will
#	be of use.  There is absolutely NO WARRANTY.
#	Permission to copy, redistribute or otherwise
#	use this file is hereby granted provided that 
#	the above copyright notice and this notice are
#	left intact. 
#      
#	Please send copies of changes and bug-fixes to:
#	sjg@crufty.net
#

ECHO_TRACE ?= echo

.ifndef Mkdirs
# A race condition in some versions of mkdir, means that it can bail 
# if another process made a dir that mkdir expected to.
# We repeat the mkdir -p a number of times to try and work around this.
# We stop looping as soon as the dir exists.
# If we get to the end of the loop, a plain mkdir will issue an error.
Mkdirs= Mkdirs() { \
	for d in $$*; do \
		for i in 1 2 3 4 5 6; do \
			mkdir -p $$d; \
			test -d $$d && return 0; \
		done > /dev/null 2>&1; \
		mkdir $$d || exit $$?; \
	done; }
.endif

# if MKOBJDIRS is set to auto (and NOOBJ isn't defined) do some magic...
# This will automatically create objdirs as needed.
# Skip it if we are just doing 'clean'.
.if ${MK_AUTO_OBJ:Uno} == "yes"
MKOBJDIRS= auto
.endif
.if !defined(NOOBJ) && !defined(NO_OBJ) && ${MKOBJDIRS:Uno} == auto
# Use __objdir here so it is easier to tweak without impacting
# the logic.
.if !empty(MAKEOBJDIRPREFIX)
.if ${.CURDIR:M${MAKEOBJDIRPREFIX}/*} != ""
# we are already in obj tree!
__objdir?= ${.CURDIR}
.endif
__objdir?= ${MAKEOBJDIRPREFIX}${.CURDIR}
.endif
__objdir?= ${MAKEOBJDIR:Uobj}
__objdir:= ${__objdir}
.if ${.OBJDIR:tA} != ${__objdir:tA}
# We need to chdir, make the directory if needed
.if !exists(${__objdir}/) && \
	(${.TARGETS} == "" || ${.TARGETS:Nclean*:N*clean:Ndestroy*} != "")
# This will actually make it... 
__objdir_made != echo ${__objdir}/; umask ${OBJDIR_UMASK:U002}; \
        ${ECHO_TRACE} "[Creating objdir ${__objdir}...]" >&2; \
        ${Mkdirs}; Mkdirs ${__objdir}
.endif
# This causes make to use the specified directory as .OBJDIR
.OBJDIR: ${__objdir}
.if ${.OBJDIR:tA} != ${__objdir:tA}
# we did not get what we want - do we care?
.if ${__objdir_made:Uno:M${__objdir}/*} != ""
# watch out for __objdir being relative path
.if !(${__objdir:M/*} == "" && ${.OBJDIR:tA} == ${${.CURDIR}/${__objdir}:L:tA})
.error could not use ${__objdir}: .OBJDIR=${.OBJDIR}
.endif
.endif
# apparently we can live with it
# make sure we know what we have
.OBJDIR: ${.CURDIR}
.endif
.endif
.endif
