# 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
# DOXYGEN          .. if non-empty, generated headers includes Doxygen's @file
# 		      command, so it is possible to document config
# 		      variables.

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

$(addprefix $(1)/,$(notdir $(addsuffix .stamp,$(2)))) : $(CONFIG_FILES)
	@$(QUIET_CMD_ECHO) "  CONFGEN $$(@:%.stamp=%)"
	@if [ ! -d `dirname $(2).tmp` ] ; then \
		mkdir -p `dirname $(2).tmp` ; fi
	@echo "/* Automatically generated from */" > "$(2).tmp"
	@echo "/* config files: $$(^:$(OUTPUT_DIR)/%=%) */" >> "$(2).tmp"
	$(if $(DOXYGEN),@echo "/** @file */" >> "$(2).tmp")
	@echo "#ifndef $(4)" >> "$(2).tmp"
	@echo "#define $(4)" >> "$(2).tmp"
	@( $(foreach x, $(shell echo '$($(3))' | tr 'x\t ' 'x\n\n' | sed -e 's/^\([^ =]*\)\(=[^ ]\+\|\)$$/\1/' ), \
		echo '$(x).$($(x))' ; ) echo ; ) | \
		sed -e '/^[^.]*\.n$$$$/d' -e '/^[^.]*\.$$$$/d' -e 's/^\([^.]*\)\.[ym]$$$$/\1.1/' | \
		sed -n -e 's/^\([^.]*\)\.\(.*\)$$$$/#define \1 \2/p' \
		  >> "$(2).tmp"
	@echo "#endif /*$(4)*/" >> "$(2).tmp"
	@touch "$$@"
	@if cmp --quiet "$(2).tmp" "$(2)" ; then rm "$(2).tmp"; \
	else mv "$(2).tmp" "$(2)" ; \
	echo "Updated configuration $(2)" ; fi

endef

ifdef LOCAL_CONFIG_H

# This must be declared after the default cflags are assigned!
# Override is used to override command line assignemnt.
override CFLAGS += -I.
$(eval $(call BUILD_CONFIG_H_template,$(USER_OBJS_DIR),$(USER_OBJS_DIR)/$(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 $(call BUILD_CONFIG_H_template,$(USER_OBJS_DIR),$(addprefix $(USER_INCLUDE_DIR)/,$(confh)),$(basename $(notdir $(confh)))_DEFINES,\
_$(basename $(notdir $(confh)))_H \
)))

config_h_stamp_files = $(addprefix $(USER_OBJS_DIR)/,$(notdir $(addsuffix .stamp,$(config_include_HEADERS) $(LOCAL_CONFIG_H))))

# Add some hooks to standard passes
include-pass-local: $(config_h_stamp_files)

ifneq ($(KERN_CONFIG_HEADERS_REQUIRED),)

ifdef LOCAL_CONFIG_H
$(eval $(call BUILD_CONFIG_H_template,$(KERN_OBJS_DIR),$(KERN_OBJS_DIR)/$(LOCAL_CONFIG_H),default_CONFIG,_LOCAL_CONFIG_H) )
endif

$(foreach confh,$(config_include_HEADERS),$(eval $(call BUILD_CONFIG_H_template,$(KERN_OBJS_DIR),$(addprefix $(KERN_INCLUDE_DIR)/,$(confh)),$(basename $(notdir $(confh)))_DEFINES,\
_$(basename $(notdir $(confh)))_H \
)))

kern_config_h_stamp_files = $(addprefix $(KERN_OBJS_DIR)/,$(notdir $(addsuffix .stamp,$(config_include_HEADERS) $(LOCAL_CONFIG_H))))

# Add some hooks to standard passes
include-pass-local: $(kern_config_h_stamp_files)

endif

clean-local: clean-local-config-h

clean-local-config-h:
	@$(foreach confh,$(config_h_stamp_files) $(kern_config_h_stamp_files),\
	    if [ -e $(confh) ] ; then rm $(confh) ; fi ; \
	)


# Local Variables:
# mode:makefile
# End: