[Buildroot] [PATCH 10/29 v2] package/boost: prepare for a configurable host variant

[Yann E. MORIN]

Even though we do not envision a host boost with nothing disabled
(i.e. with everything enabled), we still model the _WITHOUT_FLAGS
variable after the similar variable for the target variant.

Signed-off-by: Yann E. MORIN <yann.morin.1998 at free.fr>
Cc: Michael Nosthoff <buildroot at heine.tech>
Cc: Yegor Yefremov <yegorslists at googlemail.com>
---
 package/boost/boost.mk | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/package/boost/boost.mk b/package/boost/boost.mk
index 1dcc4a4b3a..6af76e1302 100644
--- a/package/boost/boost.mk
+++ b/package/boost/boost.mk
@@ -35,10 +35,13 @@ BOOST_TARGET_CXXFLAGS += -I$(STAGING_DIR)/usr/include/python$(PYTHON3_VERSION_MA
 BOOST_DEPENDENCIES += python3
 endif
 
+HOST_BOOST_FLAGS = \
+	--without-icu \
+	--with-toolset=gcc
+
 # keep host variant as minimal as possible
 # regex & system are needed by host-riscv-isa-sim
-HOST_BOOST_FLAGS = --without-icu --with-toolset=gcc \
-	--without-libraries=$(subst $(space),$(comma),\
+HOST_BOOST_WITHOUT_FLAGS = \
 	atomic \
 	chrono \
 	container \
@@ -68,8 +71,10 @@ HOST_BOOST_FLAGS = --without-icu --with-toolset=gcc \
 	timer \
 	type_erasure \
 	url \
-	wave\
-	)
+	wave
+
+HOST_BOOST_WITHOUT_FLAGS_COMMASEPARATED = $(subst $(space),$(comma),$(strip $(HOST_BOOST_WITHOUT_FLAGS)))
+HOST_BOOST_FLAGS += $(if $(HOST_BOOST_WITHOUT_FLAGS_COMMASEPARATED), --without-libraries=$(HOST_BOOST_WITHOUT_FLAGS_COMMASEPARATED))
 
 HOST_BOOST_OPTS += toolset=gcc threading=multi \
 	variant=release link=shared runtime-link=shared -j$(PARALLEL_JOBS) -q \
-- 
2.47.0