Merge pull request tensorflow#21425 from saeta/fix_tpu

Refactor dependencies so keras_support can be imported directly.

tensorflow/contrib/BUILD

@@ -107,7 +107,6 @@ py_library(
         "//tensorflow/contrib/tfprof",
         "//tensorflow/contrib/timeseries",
         "//tensorflow/contrib/tpu",
-        "//tensorflow/contrib/tpu:tpu_py",
         "//tensorflow/contrib/training:training_py",
         "//tensorflow/contrib/util:util_py",
         "//tensorflow/python:util",

tensorflow/contrib/cmake/python_protos.txt

@@ -2,6 +2,7 @@ tensorflow/core
 tensorflow/core/kernels/boosted_trees
 tensorflow/core/profiler
 tensorflow/python
+tensorflow/compiler/xla
 tensorflow/contrib/boosted_trees/proto
 tensorflow/contrib/cloud/kernels
 tensorflow/contrib/decision_trees/proto

tensorflow/contrib/distribute/python/BUILD

@@ -272,8 +272,7 @@ py_library(
     deps = [
         ":one_device_strategy",
         ":values",
-        "//tensorflow/contrib/tpu",
-        "//tensorflow/contrib/tpu:tpu_py",
+        "//tensorflow/contrib/tpu:tpu_lib",
         "//tensorflow/python:constant_op",
         "//tensorflow/python:control_flow_ops",
         "//tensorflow/python:framework_ops",

tensorflow/contrib/tpu/BUILD

@@ -46,7 +46,8 @@ py_library(
     srcs_version = "PY2AND3",
     deps = [
         ":tpu_lib",
-        ":tpu_py",
+        "//tensorflow/compiler/xla/experimental/xla_sharding",
+        "//tensorflow/compiler/xla/python_api:xla_shape",
         "//tensorflow/contrib/training:training_py",
         "//tensorflow/core:protos_all_py",
         "//tensorflow/python:array_ops",
@@ -133,7 +134,7 @@ py_library(
 
 tf_custom_op_py_library(
     name = "tpu_py",
-    srcs = glob(["python/ops/*.py"]) + ["__init__.py"],
+    srcs = glob(["python/ops/*.py"]),
     dso = [":python/ops/_tpu_ops.so"],
     kernels = [
         ":all_ops",
@@ -152,9 +153,13 @@ tf_custom_op_py_library(
 
 py_library(
     name = "tpu",
-    srcs = ["python/tpu/__init__.py"],
+    srcs = [
+        "__init__.py",
+        "python/tpu/__init__.py",
+    ],
     srcs_version = "PY2AND3",
     deps = [
+        ":keras_support",  # split out to avoid cycle with tpu_strategy
         ":tpu_estimator",
         ":tpu_lib",
     ],
@@ -166,11 +171,13 @@ py_library(
         "python/tpu/keras_support.py",
     ],
     srcs_version = "PY2AND3",
+    visibility = [
+        "//tensorflow:__subpackages__",
+    ],
     deps = [
         ":tpu_lib",
-        ":tpu_py",
         "//tensorflow/contrib/cluster_resolver:tpu_cluster_resolver_py",
-        "//tensorflow/contrib/distribute/python:tpu_strategy",
+        "//tensorflow/contrib/distribute",
         "//tensorflow/contrib/framework:framework_py",
         "//tensorflow/contrib/tpu/proto:compilation_result_proto_py",
         "//tensorflow/core:protos_all_py",

tensorflow/contrib/tpu/__init__.py

@@ -47,6 +47,9 @@
 @@TPUConfig
 
 @@bfloat16_scope
+
+@@TPUDistributionStrategy
+@@keras_to_tpu_model
 """
 
 from __future__ import absolute_import
@@ -58,6 +61,8 @@
 from tensorflow.contrib.tpu.python.ops.tpu_ops import *
 from tensorflow.contrib.tpu.python.tpu.bfloat16 import *
 from tensorflow.contrib.tpu.python.tpu.device_assignment import *
+from tensorflow.contrib.tpu.python.tpu.keras_support import tpu_model as keras_to_tpu_model
+from tensorflow.contrib.tpu.python.tpu.keras_support import TPUDistributionStrategy
 from tensorflow.contrib.tpu.python.tpu.topology import *
 from tensorflow.contrib.tpu.python.tpu.tpu import *
 from tensorflow.contrib.tpu.python.tpu.tpu_config import *

tensorflow/contrib/tpu/python/tpu/keras_support.py

@@ -55,7 +55,6 @@
 import numpy as np
 
 from tensorflow.contrib.cluster_resolver.python.training import tpu_cluster_resolver
-from tensorflow.contrib.distribute.python import tpu_strategy
 from tensorflow.contrib.framework.python.framework import experimental
 from tensorflow.contrib.tpu.proto import compilation_result_pb2 as tpu_compilation_result
 from tensorflow.contrib.tpu.python.ops import tpu_ops
@@ -82,7 +81,11 @@
 from tensorflow.python.ops import variable_scope
 from tensorflow.python.platform import tf_logging as logging
 
-TPUDistributionStrategy = tpu_strategy.TPUStrategy  # pylint: disable=invalid-name
+
+# Work-around dependency cycle between DistributionStrategy and TPU lib.
+def TPUDistributionStrategy(*args, **kw):  # pylint: disable=invalid-name
+  from tensorflow.contrib.distribute.python import tpu_strategy  # pylint: disable=g-import-not-at-top
+  return tpu_strategy.TPUStrategy(*args, **kw)
 
 
 class TPUEmbedding(embeddings.Embedding):