1 files changed, 48 insertions, 0 deletions
diff --git a/tensorflow/version_check.bzl b/tensorflow/version_check.bzl
new file mode 100644
index 0000000000..79e721dab4
--- /dev/null
+++ b/tensorflow/version_check.bzl
@@ -0,0 +1,48 @@
+""" Helpers to check minimum version of bazel."""
+
+def _extract_version_number(bazel_version):
+  """Extracts the semantic version number from a version string
+
+  Args:
+    bazel_version: the version string that begins with the semantic version
+      e.g. "1.2.3rc1 abc1234" where "abc1234" is a commit hash.
+
+  Returns:
+    The semantic version string, like "1.2.3".
+  """
+  for i in range(len(bazel_version)):
+    c = bazel_version[i]
+    if not (c.isdigit() or c == "."):
+      return bazel_version[:i]
+  return bazel_version
+
+# Parse the bazel version string from `native.bazel_version`.
+# e.g.
+# "0.10.0rc1 abc123d" => (0, 10, 0)
+# "0.3.0" => (0, 3, 0)
+def _parse_bazel_version(bazel_version):
+  """Parses a version string into a 3-tuple of ints
+
+  int tuples can be compared directly using binary operators (<, >).
+
+  Args:
+    bazel_version: the Bazel version string
+
+  Returns:
+    An int 3-tuple of a (major, minor, patch) version.
+  """
+
+  version = _extract_version_number(bazel_version)
+  return tuple([int(n) for n in version.split(".")])
+
+def check_bazel_version_at_least(minimum_bazel_version):
+  if "bazel_version" not in dir(native):
+    fail("\nCurrent Bazel version is lower than 0.2.1, expected at least %s\n" % minimum_bazel_version)
+  elif not native.bazel_version:
+    print("\nCurrent Bazel is not a release version, cannot check for compatibility.")
+    print("Make sure that you are running at least Bazel %s.\n" % minimum_bazel_version)
+    return
+
+  if _parse_bazel_version(native.bazel_version) < _parse_bazel_version(minimum_bazel_version):
+    fail("\nCurrent Bazel version is {}, expected at least {}\n".format(
+        native.bazel_version, minimum_bazel_version))