Index: configure/cmake.mk
===================================================================
RCS file: /cvsroot/pkgsrc/mk/configure/cmake.mk,v
retrieving revision 1.14
diff -u -r1.14 cmake.mk
--- configure/cmake.mk	21 Oct 2016 11:13:35 -0000	1.14
+++ configure/cmake.mk	28 Jul 2017 06:19:15 -0000
@@ -30,11 +30,17 @@
 # CMAKE_INSTALL_PREFIX
 #	Destination directory to install software. The default is ${PREFIX}.
 #
+# CMAKE_OUTSOURCE_BUILD
+#	If set to yes, build out-of-source in ${WRKDIR}/.cmake_build
+#	directory. The default is no.
+#
 
 _CMAKE_DIR=	${BUILDLINK_DIR}/cmake-Modules
 
 CMAKE_USE_GNU_INSTALL_DIRS?=	yes
 
+CMAKE_OUTSOURCE_BUILD?=		no
+
 CMAKE_INSTALL_PREFIX?=	${PREFIX}
 
 CMAKE_ARGS+=	-DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_INSTALL_PREFIX}
Index: configure/configure.mk
===================================================================
RCS file: /cvsroot/pkgsrc/mk/configure/configure.mk,v
retrieving revision 1.25
diff -u -r1.25 configure.mk
--- configure/configure.mk	1 Jun 2012 12:52:37 -0000	1.25
+++ configure/configure.mk	28 Jul 2017 06:19:15 -0000
@@ -236,9 +236,18 @@
 _CONFIGURE_CMAKE_ENV+=	BUILDLINK_DIR=${BUILDLINK_DIR}
 _CONFIGURE_CMAKE_ENV+=	${CONFIGURE_ENV}
 
+.if defined(CMAKE_OUTSOURCE_BUILD) && !empty(CMAKE_OUTSOURCE_BUILD:M[Yy][Ee][Ss])
+_DO_CONFIGURE_CMAKE_TARGET=	do-configure-cmake-outsource
+BUILD_DIRS= 			# flush
+.else
+_DO_CONFIGURE_CMAKE_TARGET=	do-configure-cmake-insource
+.endif
 
 .PHONY: do-configure-cmake
-do-configure-cmake:
+do-configure-cmake: ${_DO_CONFIGURE_CMAKE_TARGET}
+
+.PHONY: do-configure-cmake-insource
+do-configure-cmake-insource:
 .for _dir_ in ${CONFIGURE_DIRS}
 	${RUN}${_ULIMIT_CMD}						\
 	cd ${WRKSRC} && cd ${_dir_} &&					\
@@ -246,6 +255,30 @@
 		cmake ${CMAKE_ARGS} ${CMAKE_ARG_PATH}
 .endfor
 
+.if defined(CMAKE_OUTSOURCE_BUILD) && !empty(CMAKE_OUTSOURCE_BUILD:M[Yy][Ee][Ss])
+.  for _src_ in ${CONFIGURE_DIRS}
+.    if ${_src_} == ${WRKSRC}
+_suff=_build
+.    elif ${_src_:S,^${WRKSRC},,} != ${_src_}
+_suff=_build_${_src_:S,^${WRKSRC},,:S,^/,,:S,/,_,g}
+.    else
+_suff=_build_${_src_:S,/,_,g}
+.    endif
+_bin_=${WRKDIR}/.cmake${_suff}
+_CMAKE_SRCBIN_DIRS+=${_src_} ${_bin_}
+BUILD_DIRS+=${_bin_}
+.  endfor
+.endif
+
+.PHONY: do-configure-cmake-outsource
+do-configure-cmake-outsource:
+.for _src_ _bin_ in ${_CMAKE_SRCBIN_DIRS}
+	${RUN}${_ULIMIT_CMD}						\
+	${MKDIR} ${_bin_} && cd ${_bin_} &&			\
+	${PKGSRC_SETENV} ${_CONFIGURE_CMAKE_ENV}			\
+		cmake ${CMAKE_ARGS} ${CMAKE_ARG_PATH} ${_src_}
+.endfor
+
 ######################################################################
 ### pre-configure, do-configure, post-configure (PUBLIC, override)
 ######################################################################