build: add Makefile variable easy access

This adds 2 helper targets for use in scripts to easily get at Makefile
variables without parsing the Makefile or config.status.

Signed-off-by: David Lamparter <equinox@diac24.net>
This commit is contained in:
David Lamparter 2018-08-25 07:35:31 +02:00
parent 0fca9cee36
commit b8dd5f9d9b

View file

@ -8,6 +8,20 @@ AM_CPPFLAGS += -I$(top_srcdir) -I$(top_srcdir)/include -I$(top_srcdir)/lib \
DEFS = @DEFS@ -DSYSCONFDIR=\"$(sysconfdir)/\" -DCONFDATE=$(CONFDATE)
LIBCAP = @LIBCAP@
# these two targets are provided to easily grab autoconf/Makefile variables
# you can use either:
# eval `make VARFD=3 shvar-CFLAGS 3>&1 1>&2`
# CFLAGS="`make VARFD=3 var-CFLAGS 3>&1 1>&2`"
# where the former can be used to set several variables at once. Note the
# fd redirections -- this is to prevent garbage from make rebuilding other
# targets from causing issues.
.PHONY: shvar-% var-%
VARFD ?= 1
shvar-%:
@echo "$*=\"$($*)\"" >&$(VARFD)
var-%:
@echo "$($*)" >&$(VARFD)
# overwriting these vars breaks cross-compilation. let's be helpful and warn.
#
# note: "#AUTODERP# " will be removed from Makefile by configure. These are