From 9591832112cb1fa1553bb6d1057bcc53bf4074cd Mon Sep 17 00:00:00 2001
From: Graydon Hoare <graydon@mozilla.com>
Date: Thu, 27 Jun 2013 17:10:07 -0700
Subject: [PATCH] mk: add mechanisms for triggering clean-llvm builds from
 commits

---
 Makefile.in                          | 11 ++++++++++-
 mk/clean.mk                          |  2 +-
 src/rustllvm/llvm-auto-clean-trigger |  0
 3 files changed, 11 insertions(+), 2 deletions(-)
 create mode 100644 src/rustllvm/llvm-auto-clean-trigger

diff --git a/Makefile.in b/Makefile.in
index 0404e2bdee6..7d1d8c7996d 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -536,10 +536,19 @@ ALL_TARGET_RULES = $(foreach target,$(CFG_TARGET_TRIPLES), \
 	$(foreach host,$(CFG_HOST_TRIPLES), \
  all-target-$(target)-host-$(host)))
 
-all: $(ALL_TARGET_RULES) $(GENERATED) docs
+all: rustllvm/llvm-auto-clean-stamp \
+     $(ALL_TARGET_RULES) $(GENERATED) docs
 
 endif
 
+# This is used to independently force an LLVM clean rebuild
+# when we changed something not otherwise captured by builtin
+# dependencies. In these cases, commit a change that touches
+# the stamp in the source dir.
+rustllvm/llvm-auto-clean-stamp: $(S)src/rustllvm/llvm-auto-clean-trigger
+	$(Q)$(MAKE) clean-llvm
+	touch $@
+
 
 ######################################################################
 # Re-configuration
diff --git a/mk/clean.mk b/mk/clean.mk
index 23efbb3ee15..32dd3902b1f 100644
--- a/mk/clean.mk
+++ b/mk/clean.mk
@@ -23,7 +23,7 @@ CLEAN_LLVM_RULES = 								\
  $(foreach target, $(CFG_TARGET_TRIPLES),		\
   clean-llvm$(target))
 
-.PHONY: clean clean-all clean-misc
+.PHONY: clean clean-all clean-misc clean-llvm
 
 clean-all: clean clean-llvm
 
diff --git a/src/rustllvm/llvm-auto-clean-trigger b/src/rustllvm/llvm-auto-clean-trigger
new file mode 100644
index 00000000000..e69de29bb2d