+define RequireHeader
+ define Require/$(1)
+ [ -e "$(1)" ]
+ endef
+
+ $$(eval $$(call Require,$(1),$(2)))
+endef
+
+define QuoteHostCommand
+'$(subst ','"'"',$(strip $(1)))'
+endef
+
+# 1: display name
+# 2: failure message
+# 3: test
+define TestHostCommand
+ define Require/$(1)
+ ($(3)) >/dev/null 2>/dev/null
+ endef
+
+ $$(eval $$(call Require,$(1),$(2)))
+endef
+
+# 1: canonical name
+# 2: failure message
+# 3+: candidates
+define SetupHostCommand
+ define Require/$(1)
+ [ -f "$(STAGING_DIR_HOST)/bin/$(strip $(1))" ] && exit 0; \
+ for cmd in $(call QuoteHostCommand,$(3)) $(call QuoteHostCommand,$(4)) \
+ $(call QuoteHostCommand,$(5)) $(call QuoteHostCommand,$(6)) \
+ $(call QuoteHostCommand,$(7)) $(call QuoteHostCommand,$(8)) \
+ $(call QuoteHostCommand,$(9)); do \
+ if [ -n "$$$$$$$$cmd" ]; then \
+ bin="$$$$$$$$(PATH="$(subst $(space),:,$(filter-out $(STAGING_DIR_HOST)/%,$(subst :,$(space),$(PATH))))" \
+ which "$$$$$$$${cmd%% *}")"; \
+ if [ -x "$$$$$$$$bin" ] && eval "$$$$$$$$cmd" >/dev/null 2>/dev/null; then \
+ mkdir -p "$(STAGING_DIR_HOST)/bin"; \
+ ln -sf "$$$$$$$$bin" "$(STAGING_DIR_HOST)/bin/$(strip $(1))"; \
+ exit 0; \
+ fi; \
+ fi; \
+ done; \
+ exit 1
+ endef
+
+ $$(eval $$(call Require,$(1),$(if $(2),$(2),Missing $(1) command)))
+endef