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authorLuke Shumaker <lukeshu@lukeshu.com>2017-08-20 16:54:15 -0400
committerLuke Shumaker <lukeshu@lukeshu.com>2017-08-20 16:54:15 -0400
commitdbd9fa35e5dd40d33d8be9c899f3d56918aba34f (patch)
tree8c6f5beaecdad99caa724516643e33c2070fedc9 /build-aux/Makefile.once.head/00-var.mk
parente4b0a9391be1d21ca15d9610b977f989ccee833a (diff)
parenteaf336a9265399520e3cf71d4979446b98bdf48d (diff)
Merge remote-tracking branch 'r-autothing/v3/master'
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+# Copyright (C) 2016-2017 Luke Shumaker
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+mod.var.description = Depend on the values of variables
+define mod.var.doc
+# Inputs:
+# (user-defined)
+# Outputs:
+# Target : `$(outdir)/.var.%`
+# Directory variable: `at.targets`
+# Directory variable: `var.`
+#
+# It's a well-known secret that many files generated by a Makefile vary with
+# the values of particular variables, but that GNU Make can't track these
+# dependencies. Well, with some cleverness, it actually can!
+#
+# With this module, to depend on the value of a variable, depend on
+# `$(outdir)/.var.VARNAME`, or `$(var.)VARNAME` for short.
+endef
+mod.var.doc := $(value mod.var.doc)
+
+var. = $(patsubst ./%,%,$(outdir)/.var.)
+
+.PHONY: _var.FORCE