--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/make/SourceRevision.gmk	Mon Nov 28 09:20:13 2016 +0100
@@ -0,0 +1,132 @@
+#
+# Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+#
+# This code is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License version 2 only, as
+# published by the Free Software Foundation.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# This code 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 General Public License
+# version 2 for more details (a copy is included in the LICENSE file that
+# accompanied this code).
+#
+# You should have received a copy of the GNU General Public License version
+# 2 along with this work; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+# or visit www.oracle.com if you need additional information or have any
+# questions.
+#
+
+default: all
+
+include $(SPEC)
+include MakeBase.gmk
+
+################################################################################
+# Keep track of what source revision is used to create the build, by creating
+# a tracker file in the output directory. This tracker file is included in the
+# image, and can be used to recreate the source revision used.
+#
+# We're either building directly from a mercurial forest, and if so, use the
+# current revision from mercurial. Otherwise, we are building from a source
+# bundle. As a part of creating this source bundle, the current mercurial
+# revisions of all repos will be stored in a file in the top dir, which is then
+# used when creating the tracker file.
+
+STORED_SOURCE_REVISION := $(TOPDIR)/.src-rev
+
+# Are we using mercurial?
+ifneq ($(and $(HG), $(wildcard $(TOPDIR)/.hg)), )
+
+  # Verify that the entire forest is consistent
+  $(foreach repo, $(call FindAllReposRel), \
+    $(if $(wildcard $(TOPDIR)/$(repo)/.hg),, \
+        $(error Inconsistent revision control: $(repo) is missing .hg directory)) \
+  )
+
+  # Replace "." with "_top" and "/" with "-"
+  MakeFilenameFromRepo = \
+      $(strip $(subst .,top, $(subst /,-, $1)))
+
+  ################################################################################
+  # SetupGetRevisionForRepo defines a make rule for creating a file containing
+  # the name of the repository and the output of "hg id" for that repository.
+  # Argument 1 is the relative path to the repository from the top dir.
+  #
+  SetupGetRevisionForRepo = $(NamedParamsMacroTemplate)
+  define SetupGetRevisionForRepoBody
+    $1_REPO_PATH :=  $$(TOPDIR)/$$(strip $1)
+    $1_FILENAME := $$(call MakeFilenameFromRepo, $1)
+
+    $$(SUPPORT_OUTPUTDIR)/src-rev/$$($1_FILENAME): FRC
+	$(call MakeDir $$(@D))
+	$(ECHO) $$(strip $1):`$(HG) id -i --repository $$($1_REPO_PATH)` > $$@
+
+    REPO_REVISIONS += $$(SUPPORT_OUTPUTDIR)/src-rev/$$($1_FILENAME)
+  endef
+
+  # Setup rules for all repos. This makes sure all the "hg id" calls are made
+  # in parallel.
+  $(foreach repo, $(call FindAllReposRel), \
+    $(eval $(call SetupGetRevisionForRepo, $(repo))) \
+  )
+
+  # Create a complete source revision output file from all repos
+  # Param 1: The output file
+  define CreateSourceRevisionFile
+    $1: $$(REPO_REVISIONS)
+	$(call MakeDir $$(@D))
+	$$(ECHO) `$$(CAT) $$(REPO_REVISIONS)` > $$@.tmp
+	if [ ! -f $$@ ] || [ "`$$(CAT) $$@`" != "`$$(CAT) $$@.tmp`" ]; then \
+	  $$(MV) $$@.tmp $$@ ; \
+	else \
+	  $$(RM) $$@.tmp ; \
+	fi
+  endef
+
+  $(eval $(call CreateSourceRevisionFile, $(STORED_SOURCE_REVISION)))
+
+  store-source-revision: $(STORED_SOURCE_REVISION)
+
+  $(eval $(call CreateSourceRevisionFile, $(SOURCE_REVISION_TRACKER)))
+
+  create-source-revision-tracker: $(SOURCE_REVISION_TRACKER)
+
+else
+  # Not using HG
+
+  ifneq ($(wildcard $(STORED_SOURCE_REVISION)), )
+    # We have a stored source revision (.src-rev)
+
+    store-source-revision:
+	$(call LogWarn, Warning: No mercurial configuration present, not updating .src-rev)
+
+    $(SOURCE_REVISION_TRACKER): $(STORED_SOURCE_REVISION)
+	$(install-file)
+
+    create-source-revision-tracker: $(SOURCE_REVISION_TRACKER)
+  else
+    # We don't have a stored source revision. Can't do anything, really.
+
+    store-source-revision:
+	$(call LogWarn, Error: No mercurial configuration present, cannot create .src-rev)
+	exit 2
+
+    create-source-revision-tracker:
+	$(call LogWarn, Error: No mercurial configuration present and no .src-rev)
+	exit 2
+  endif
+
+endif
+
+all: store-source-revision create-source-revision-tracker
+
+FRC: # Force target
+
+.PHONY: all store-source-revision create-source-revision-tracker