Create comma-separated lists in GNU Make
I have a Makefile with a set of booleans which must be used to control the flags for an external application. The problem is that the flag must be passed as a comma-separated string.
Something like this (non-working pseudo code):
WITH_LIST = ""
WITHOUT_LIST = ""
ifeq ($(BOOL_A),y)
# Append A 开发者_JS百科to list "WITH_LIST"
else
# Append A to list "WITHOUT_LIST"
endif
ifeq ($(BOOL_B),y)
# Append B to list "WITH_LIST"
else
# Append B to list "WITHOUT_LIST"
endif
ifeq ($(BOOL_C),y)
# Append C to list "WITH_LIST"
else
# Append C to list "WITHOUT_LIST"
endif
Now assuming BOOL_A == y, BOOL_B == n and BOOL_C == y, I need to run the following command:
./app --with=A,C --with-out=B
How can I generate these string using Gnu Make?
First you create the two white-space separated lists, either using your method, or thiton's.
Then you use the little trick from the end of section 6.2 of the GNU make manual to create a variable holding a single space, and one holding a comma. You can then use these in $(subst ...)
to change the two lists to comma-separated.
PARTS := A B C BOOL_A := y BOOL_B := n BOOL_C := y WITH_LIST := $(foreach part, $(PARTS), $(if $(filter y, $(BOOL_$(part))), $(part))) WITHOUT_LIST := $(filter-out $(WITH_LIST), $(PARTS)) null := space := $(null) # comma := , WITH_LIST := $(subst $(space),$(comma),$(strip $(WITH_LIST))) WITHOUT_LIST := $(subst $(space),$(comma),$(strip $(WITHOUT_LIST))) all: ./app --with=$(WITH_LIST) --with-out=$(WITHOUT_LIST)
A construct like
OPTIONS+=$(if $(filter y,$(BOOL_A)),--with=A,--with-out=A)
should work.
Edit: Sorry, overlooked the necessary collation.
PARTS=A B C
YESSES=$(foreach i,$(PARTS),$(if $(filter y,$(BOOL_$(i))),$(i)))
all:
echo with=$(shell echo $(YESSES) | tr ' ' ',')
The idea is to check for each possible part X whether it's set to yes and insert it into a list if it is yes. This list is whitespace-separated and hard to comma-separate with make, but easy to do this in shell.
Or just use sed
: ugly (and untested) but straightforward
WITH_LIST = $(shell echo A$(BOOL_A) B$(BOOL_B) C$(BOOL_C) | sed -e 's/[ABC][^yABC]*//g' -e 's/y//g' -e 's/ /,/g')
WITHOUT_LIST = $(shell echo A$(BOOL_A) B$(BOOL_B) C$(BOOL_C) | sed -e 's/[ABC]y[^ABC]*//g' -e 's/[^ABC ]//g' -e 's/ /,/g')
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