+# Get settings from the output of configure by running it to generate
+# Makefile.config if it doesn't exist yet.
+
+# If Makefile.config doesn't exist, then srcdir won't be
+# set. Conditionally set it (assuming a plain srcdir build) so that
+# the rule to generate Makefile.config can actually work.
+srcdir ?= .
+
+include Makefile.config
+Makefile.config: $(srcdir)/configure
+ifeq ($(configure_options),)
+ @echo ""
+ @echo "Note: Calling ./configure with no command-line arguments. This is often fine,"
+ @echo " but if you want to specify any arguments (such as an alternate prefix"
+ @echo " into which to install), call ./configure explicitly and then make again."
+ @echo " See \"./configure --help\" for more details."
+ @echo ""
+endif
+ $(srcdir)/configure $(configure_options)
+