CODEWITHSUNDEEP
makefile
Camarada
Camarada

Reputation: 107

Makefile check existence of variable from list

I have a Makefile:

#Build Configurations
CONFIGS = Debug Release Profile

#Config flags
Debug_Flags=dasd
Release_Flags=

.SECONDEXPANSION:

#Debug_safety_check Release_safety_check Profile_safety_check targets
$(addsuffix _safety_check,$(CONFIGS)):
#Check existence of variable
ifeq '$(origin $(subst safety_check,FLAGS,$@))' 'undefined'
    $(error $(subst safety_check,FLAGS,$@) variable undefined)
endif 

#How to make our configurations (do corresponding safety_checks)
$(CONFIGS): $$@_safety_check

This line is incorrect:

ifeq '$(origin $(subst safety_check,FLAGS,$@))' 'undefined'

I think, It is because $@ expansion occurs, when calling corresponding safety check. But ifeq expansion occurs "immediately", so, in fact, we get such line:

ifeq '$(origin ' ') 'undefined'

Does some method of check variables definition from list exist?

Upvotes: 2

Views: 2075

Answers (1)

Camarada
Camarada

Reputation: 107

Ufff, gotcha.

#Build Configurations
CONFIGS = Debug Release Profile

#Config flags
Debug_Flags=dasd
Release_Flags=
#Profile_Flags=

#Adds _flags suffix for each variable, 
#get it's origin ('undefined' for undefined variables).
#If $(findstring) a lookup for the word 'undefined' succeeds, 
#adds to the result variable
undef_flags = $(foreach c, $(CONFIGS), \
                $(if $(findstring undefined, $(origin $c_Flags)), $c))

#Count words for undefined configs, must be not '0'
ifneq ($(words $(undef_flags)),0)
#strip because if flag is undefined we'll get the trash spaces
$(error Flags ($(strip $(undef_flags))) must be defined)
endif

Upvotes: 1

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