+ifneq ($(CONFIG_DEBUG),y)
+CFLAGS += $(call cc-option,-Os,$(call cc-option,-O2,))
+else
+CFLAGS += $(call cc-option,-g,)
+#CFLAGS += "-D_FORTIFY_SOURCE=2"
+ifeq ($(CONFIG_DEBUG_PESSIMIZE),y)
+CFLAGS += $(call cc-option,-O0,)
+else
+CFLAGS += $(call cc-option,-Os,$(call cc-option,-O2,))
+endif
+endif
+
+# If arch/$(ARCH)/Makefile did not override it (with, say, -fPIC)...
+ARCH_FPIC ?= -fpic
+ARCH_FPIE ?= -fpie
+ARCH_PIE ?= -pie
+
+# Usage: $(eval $(call pkg_check_modules,VARIABLE-PREFIX,MODULES))
+define pkg_check_modules
+$(1)_CFLAGS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --cflags $(2))
+$(1)_LIBS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --libs $(2))
+endef
+
+ifeq ($(CONFIG_BUILD_LIBBUSYBOX),y)
+# on i386: 14% smaller libbusybox.so
+# (code itself is 9% bigger, we save on relocs/PLT/GOT)
+CFLAGS += $(ARCH_FPIC)
+# and another 4% reduction of libbusybox.so:
+# (external entry points must be marked EXTERNALLY_VISIBLE)
+CFLAGS += $(call cc-option,-fvisibility=hidden)