# Generate/check/update a .h file to reflect the values of Makefile
# variables
#
# Example usage (by default, check-conf-h will consider all CFG_*
# and _CFG_* variables):
#
# path/to/conf.h: FORCE
# $(call check-conf-h)
#
# Or, to include only the variables with the given prefix(es):
#
# path/to/crypto_config.h: FORCE
# $(call check-conf-h,CFG_CRYPTO_ CRYPTO_)
define check-conf-h
$(q)set -e; \
echo ' CHK $@'; \
cnf="$(strip $(foreach var, \
$(call cfg-vars-by-prefix,$1), \
$(call cfg-make-define,$(var))))"; \
guard="_`echo $@ | tr -- -/. ___`_"; \
mkdir -p $(dir $@); \
echo "#ifndef $${guard}" >$@.tmp; \
echo "#define $${guard}" >>$@.tmp; \
echo -n "$${cnf}" | sed 's/_nl_ */\n/g' >>$@.tmp; \
echo "#endif" >>$@.tmp; \
if [ -r $@ ] && cmp -s $@ $@.tmp; then \
rm -f $@.tmp; \
else \
echo ' UPD $@'; \
mv $@.tmp $@; \
fi
endef
define cfg-vars-by-prefix
$(strip $(if $(1),$(call _cfg-vars-by-prefix,$(1)),
$(call _cfg-vars-by-prefix,CFG_ _CFG_)))
endef
define _cfg-vars-by-prefix
$(sort $(foreach prefix,$(1),$(filter $(prefix)%,$(.VARIABLES))))
endef
# Convert a makefile variable to a #define
# <undefined>, n => <undefined>
# y => 1
# <other value> => <other value>
define cfg-make-define
$(strip $(if $(filter y,$($1)),
#define $1 1 /* '$($1)' */_nl_,
$(if $(filter xn x,x$($1)),
/* $1 is not set ('$($1)') */_nl_,
#define $1 $($1) /* '$($1)' */_nl_)))
endef
# Returns 'y' if at least one variable is 'y', empty otherwise
# Example:
# FOO_OR_BAR := $(call cfg-one-enabled, FOO BAR)
cfg-one-enabled = $(if $(filter y, $(foreach var,$(1),$($(var)))),y,)
# Returns 'y' if all variables are 'y', empty otherwise
# Example:
# FOO_AND_BAR := $(call cfg-all-enabled, FOO BAR)
cfg-all-enabled = \
$(strip \
$(if $(1), \
$(if $(filter y,$($(firstword $(1)))), \
$(call cfg-all-enabled,$(filter-out $(firstword $(1)),$(1))), \
), \
y \
) \
)
# Disable a configuration variable if some dependency is disabled
# Example:
# $(eval $(call cfg-depends-all,FOO,BAR BAZ))
# Will clear FOO if it is initially 'y' and BAR or BAZ are not 'y'
cfg-depends-all = \
$(strip \
$(if $(filter y, $($(1))), \
$(if $(call cfg-all-enabled,$(2)), \
, \
$(warning Warning: Disabling $(1) [requires $(strip $(2))]) \
override $(1) := \
) \
) \
)
# Disable a configuration variable if all dependencies are disabled
# Example:
# $(eval $(call cfg-depends-one,FOO,BAR BAZ))
# Will clear FOO if it is initially 'y' and both BAR and BAZ are not 'y'
cfg-depends-one = \
$(strip \
$(if $(filter y, $($(1))), \
$(if $(call cfg-one-enabled,$(2)), \
, \
$(warning Warning: Disabling $(1) [requires (one of) $(strip $(2))]) \
override $(1) := \
) \
) \
)