# LOCAL_CONFIG_H   .. name of local config.h file generated from values
#                     of options defined in the current directory
# config_include_HEADERS .. names of global config files (possibly
#                     with subdirectories)
# xxx_DEFINES      .. list of config directives to be included in
#                     config header file of the name <somedir>/xxx.h

# Syntax: $(call BUILD_CONFIG_H_template,<header_file_path>,<list_of_options_to_export>,<header_barrier>)
define BUILD_CONFIG_H_template

$(1) : $(wildcard $(CONFIG_FILE)) $(wildcard $(CONFIG_FILE)-default)
	@$(QUIET_CMD_ECHO) "  CONFGEN $$(@:$(MAKERULES_DIR)/%=%)"
	@if [ ! -d `dirname $(1).tmp` ] ; then \
		mkdir `dirname $(1).tmp` ; fi
	@echo "/* Automatically generated from */" > "$(1).tmp"
	@echo "/* config file: $$< */" >> "$(1).tmp"
	@echo "#ifndef $(3)" >> "$(1).tmp"
	@echo "#define $(3)" >> "$(1).tmp"
	@( $(foreach x, $(shell echo '$($(2))' | sed -e 's/\<\([^ =]*\)\(=[^ ]\+\|\)\>/\1/g' ), \
		echo '$(x).$($(x))' ; ) echo ; ) | \
		sed -e '/^[^.]*\.n$$$$/d' -e '/^[^.]*\.$$$$/d' -e 's/^\([^.]*\)\.[ym]$$$$/\1.1/' | \
		sed -n -e 's/^\([^.]*\)\.\(.*\)$$$$/#define \1 \2/p' \
		  >> "$(1).tmp"
	@echo "#endif /*$(3)*/" >> "$(1).tmp"
	@if cmp --quiet "$(1).tmp" "$(1)" ; then rm "$(1).tmp" ; \
	else mv "$(1).tmp" "$(1)" ; \
	echo Updated configuration "$(1)" ; fi

endef

ifdef LOCAL_CONFIG_H

CFLAGS += -I.
$(eval $(call BUILD_CONFIG_H_template,$(LOCAL_CONFIG_H),default_CONFIG,_LOCAL_CONFIG_H) )

endif

# Special rules for configuration exported headers

#FIXME: The directory for headers should not be specified here.
$(foreach confh,$(config_include_HEADERS),$(eval $(call BUILD_CONFIG_H_template,$(addprefix $(USER_INCLUDE_DIR)/,$(confh)),$(basename $(notdir $(confh)))_DEFINES,\
_$(basename $(notdir $(confh)))_H \
)))

# Add some hooks to standard passes
include-pass-local: $(addprefix $(USER_INCLUDE_DIR)/,$(config_include_HEADERS))

clean-local: clean-local-config-h

clean-local-config-h:
	@$(foreach confh,$(addprefix $(USER_INCLUDE_DIR)/,$(config_include_HEADERS)),\
	    if [ -e $(confh) ] ; then touch -t 200001010101 $(confh) ; fi ; \
	)


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# mode:makefile
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