makefile: deprecate the legacy Makefile

requires make to be called this way:

	make I_KNOW_MAKEFILE_IS_DEPRECATED=1

diff --git a/Makefile b/Makefile
index 7e29224543a0771dcaec15bf07c16685f9e6f768..5a9252eac8b5c9e37c963cd65ef1e1bf14dae0bf 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,10 @@
+ifeq ($(I_KNOW_MAKEFILE_IS_DEPRECATED),)
+    $(shell printf 'ERROR: Makefile build is deprecated, use CMake instead, see README.md\n\n' >&2)
+    $(error I_KNOW_MAKEFILE_IS_DEPRECATED is not set)
+else
+    $(shell printf 'WARNING: deprecated Makefile build enforced\n\n' >&2)
+endif
+
 MAKEFILE_CONF      ?= Makefile.conf
 -include $(MAKEFILE_CONF)