BUILD: makefile: add a function to collect all options' CFLAGS/LDFLAGS
The new function collect_opts_flags now scans all USE_* options defined
in use_opts and appends the corresponding *_CFLAGS and *_LDFLAGS to
OPTIONS_{C,LD}FLAGS respectively. This will be useful to get rid of all
the individual concatenations to these variables.
diff --git a/include/make/options.mk b/include/make/options.mk
index f439be3..9e96f87 100644
--- a/include/make/options.mk
+++ b/include/make/options.mk
@@ -37,3 +37,16 @@
# preset all variables for all supported build options among use_opts
reset_opts_vars = $(foreach opt,$(patsubst USE_%,%,$(use_opts)) SSL WOLFSSL,$(call reset_opt_vars,$(opt)))
+
+# append $(1)_{C,LD}FLAGS into OPTIONS_{C,LD}FLAGS if not empty
+define collect_opt_flags =
+ ifneq ($$($(1)_CFLAGS),)
+ OPTIONS_CFLAGS += $$($(1)_CFLAGS)
+ endif
+ ifneq ($$($(1)_LDFLAGS),)
+ OPTIONS_LDFLAGS += $$($(1)_LDFLAGS)
+ endif
+endef
+
+# collect all known USE_foo's foo_{C,LD}FLAGS into OPTIONS_{C,LD}FLAGS
+collect_opts_flags = $(foreach opt,$(patsubst USE_%,%,$(use_opts)) SSL,$(eval $(call collect_opt_flags,$(opt))))