Advanced options concatenation in buildroot package .mk file

Question

I'm creating a buildroot package for xmms2 which uses waf build system. For the configuration step I need to pass the parameters based on the config selection. Actually it's one parameter which has comma separated values. It should look like this:

--with-optionals medialib-updater,s4

I don't see the way to generate that value. Here is what tried:

################################################################################
#
# xmms2
#
################################################################################

XMMS2_VERSION = c081011ddc280908678709d1e80f7ec57efa7b82
XMMS2_SITE = https://github.com/Gamadril/xmms2-devel
XMMS2_SITE_METHOD = git
XMMS2_GIT_SUBMODULES = YES

XMMS2_LICENSE = LGPL-2.1
XMMS2_LICENSE_FILES = COPYING

XMMS2_INSTALL_STAGING = YES

XMMS2_CONF_OPTS = --with-optionals medialib-updater 

ifeq ($(BR2_PACKAGE_XMMS2_DB_S4),y)
XMMS2_CONF_OPTS += ,s4 
endif

$(eval $(waf-package))

The result is: --with-optionals medialib-updater ,s4 - with a space between. How to get rid of that space? So actually how to concatenate some strings with a separator?

Luca Ceresoli · Accepted Answer · 2020-02-20T09:36:36.580

2

In make, the += operator always adds a space. You can append without space by using expansion:

XMMS2_CONF_OPTS := "$(XMMS2_CONF_OPTS),s4"

edited Feb 20 '20 at 09:36

answered Feb 20 '20 at 08:27

Luca Ceresoli

1,591
8
19

Thanks, tried it but got an error: `*** Recursive variable 'XMMS2_CONF_OPTS' references itself (eventually). Stop.` – Gamadril Feb 20 '20 at 08:45
I guess it should be `XMMS2_CONF_OPTS := $(XMMS2_CONF_OPTS),s4` – Gamadril Feb 20 '20 at 08:47
You're right, it should be `=` or `:=`. Fixed that in the answer. Thanks. – Luca Ceresoli Feb 20 '20 at 08:52
with `=` I get the same self-reference-error, with `:=` it works – Gamadril Feb 20 '20 at 09:02

Advanced options concatenation in buildroot package .mk file

1 Answers1