Introduce hook to BazelWorkspaceStatusModule that calls external

script(controled by workspace_status_command option, default to
tools/buildstamp/get_workspace_status) to emit addtional workspace
information to stable-status.txt.

This should address #216.

--
Change-Id: Iffb06482489f0d55393e27b0764e6e127fedbc20
Reviewed-on: https://bazel-review.git.corp.google.com/#/c/1550
MOS_MIGRATED_REVID=97678871

2 files changed, 37 insertions, 0 deletions

diff --git a/tools/buildstamp/BUILD b/tools/buildstamp/BUILD
new file mode 100644
index 0000000000..6ad7e59454
--- /dev/null
+++ b/tools/buildstamp/BUILD
@@ -0,0 +1,8 @@
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "all",
+    srcs = [
+        "get_workspace_status",
+    ],
+)
diff --git a/tools/buildstamp/get_workspace_status b/tools/buildstamp/get_workspace_status
new file mode 100644
index 0000000000..1c358f7fe2
--- /dev/null
+++ b/tools/buildstamp/get_workspace_status
@@ -0,0 +1,29 @@
+#!/bin/bash
+
+# This script will be run bazel when building process starts to
+# generate key-value information that represents the status of the
+# workspace. The output should be like
+#
+# KEY1 VALUE1
+# KEY2 VALUE2
+#
+# If the script exits with non-zero code, it's considered as a failure
+# and the output will be discarded.
+
+# The code below presents an implementation that works for git repository
+git_rev=$(git rev-parse HEAD)
+if [[ $? != 0 ]];
+then
+    exit 1
+fi
+echo "BUILD_SCM_REVISION ${git_rev}"
+
+# Check whether there are any uncommited changes
+git diff-index --quiet HEAD --
+if [[ $? == 0 ]];
+then
+    tree_status="Clean"
+else
+    tree_status="Modified"
+fi
+echo "BUILD_SCM_STATUS ${tree_status}"