1 files changed, 54 insertions, 0 deletions
diff --git a/docs/mk/common.rules.mk b/docs/mk/common.rules.mk
new file mode 100644
index 0000000000..698f43317e
--- /dev/null
+++ b/docs/mk/common.rules.mk
@@ -0,0 +1,54 @@
+##===- docs/mk/common.rules.mk -----------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+
+# Emit an error for any missing variables which are required to be defined
+# before including this makefile-module.
+#
+_DOCS.vars.missing := $(foreach v,$(DOCS.vars.mandatory),$(if $($v),,$v))
+
+ifneq (,$(strip $(_DOCS.vars.missing)))
+$(call fn.DUMP.errorn,undefined variable,$(_DOCS.vars.missing))
+endif
+
+##===----------------------------------------------------------------------===##
+
+# Basic target to build directory of output files.
+# Opaque file lists not visible to target rules need not be added here.
+#
+$(sort $(dir $(DOCS.mkdir.files))):
+	$(Echo) Creating directory $(@:$(PROJ_OBJ_ROOT)/%=%)
+	$(Verb) $(MKDIR) $@
+
+##===----------------------------------------------------------------------===##
+
+# Print help defined by variables added to the help list.
+#
+.PHONY:
+help:
+	$(foreach h,$(HELP.sections),$(info $())$(info $($h)))
+	$(info $())
+
+##===----------------------------------------------------------------------===##
+
+printvars:: $(DOCS.vars.mandatory:%=%.print.var)
+printvars:: $(DOCS.vars.print:%=%.print.var)
+
+.PHONY: %.printvar
+%.print.var:
+	@echo '$($*)' | awk -v name='$*' '{ printf("llvm[$(MAKELEVEL)]: %-13s:  %s\n",name,$$0) }'
+
+##===----------------------------------------------------------------------===##
+
+.PHONY: vars
+vars: $(sort $(foreach n,$(filter-out \
+    .VARIABLES $(HELP.sections) HELP.%,$(.VARIABLES)),$n.print2.var))
+
+.PHONY: %.print2.var
+%.print2.var:
+	@echo "$* = $($*)"