1 files changed, 66 insertions, 0 deletions
diff --git a/20130123/mk/srctop.mk b/20130123/mk/srctop.mk
new file mode 100644
index 0000000..fab090c
--- /dev/null
+++ b/20130123/mk/srctop.mk
@@ -0,0 +1,66 @@
+# $Id: srctop.mk,v 1.3 2012/11/11 23:20:18 sjg Exp $
+#
+#	@(#) Copyright (c) 2012, 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
+#
+
+.if !defined(SRCTOP)
+# if using mk(1) SB will be set.
+.ifdef SB
+.if ${.CURDIR:S,${SB},,} != ${.CURDIR}
+# we are actually within SB
+.ifdef SB_SRC
+SRCTOP:= ${SB_SRC}
+.elif exists(${SB}/src)
+SRCTOP:= ${SB}/src
+.else
+SRCTOP:= ${SB}
+.endif
+.endif
+.endif
+
+.if !defined(SRCTOP)
+.for rd in share/mk build/mk mk
+.if ${_this_mk_dir:M*${rd}} != ""
+.if ${.CURDIR:S,${_this_mk_dir:${rd:C,[^/]+,H,g:S,/, ,g:ts:}},,} != ${.CURDIR}
+SRCTOP:= ${_this_mk_dir:${rd:C,[^/]+,H,g:S,/, ,g:ts:}}
+.endif
+.endif
+.endfor
+.endif
+
+.if !defined(SRCTOP)
+_SRCTOP_TEST_?= [ -f ../.sandbox-env -o -d share/mk ]
+# Linux at least has a bug where attempting to check an automounter
+# directory will hang.  So avoid looking above /a/b
+SRCTOP!= cd ${.CURDIR}; while :; do \
+		here=`pwd`; \
+		${_SRCTOP_TEST_} && { echo $$here; break; }; \
+		case $$here in /*/*/*) cd ..;; *) echo ""; break;; esac; \
+		done 
+.endif
+.if defined(SRCTOP) && exists(${SRCTOP}/.)
+.export SRCTOP
+.endif
+.endif
+
+.if !defined(OBJTOP) && !empty(SRCTOP)
+.if defined(MAKEOBJDIRPREFIX) && exists(${MAKEOBJDIRPREFIX}${SRCTOP})
+OBJTOP= ${MAKEOBJDIRPREFIX}${SRCTOP}
+.elif (exists(${SRCTOP}/Makefile) || exists(${SRCTOP}/makefile))
+OBJTOP!= cd ${SRCTOP} && ${PRINTOBJDIR}
+.endif
+.if empty(OBJTOP)
+OBJTOP= ${SRCTOP}
+.endif
+.export OBJTOP
+.endif