Introduce a helper for registering all TF dialects (NFC)

This is part of a series of patches intended to make MLIR Dialects explictly
registered and remove the "always_link" global-constructor based registration.
The registration is mainly for tools that need to parse a "TF" MLIR input.

PiperOrigin-RevId: 328161577
Change-Id: I533930a804d2a22b76d0ef36b5970b80500542ea

tensorflow/compiler/mlir/tensorflow/BUILD

@@ -513,6 +513,7 @@ cc_library(
         "ir/tf_saved_model.cc",
     ],
     hdrs = [
+        "dialect_registration.h",
         "ir/tf_device.h",
         "ir/tf_executor.h",
         "ir/tf_ops.h",
@@ -1088,6 +1089,7 @@ cc_library(
     srcs = ["translate/translate_tf_dialect_op.cc"],
     deps = [
         ":export_tf_dialect_op",
+        ":tensorflow",
         "@llvm-project//llvm:Support",
         "@llvm-project//mlir:IR",
         "@llvm-project//mlir:Support",
@@ -1408,6 +1410,7 @@ cc_library(
     deps = [
         ":convert_graphdef",
         ":mlir_roundtrip_flags",
+        ":tensorflow",
         ":translate_cl_options",
         ":translate_lib",
         "//tensorflow/core:protos_all_cc",

tensorflow/compiler/mlir/tensorflow/dialect_registration.h

+/* Copyright 2020 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#ifndef TENSORFLOW_COMPILER_MLIR_TENSORFLOW_DIALECT_REGISTRATION_H_
+#define TENSORFLOW_COMPILER_MLIR_TENSORFLOW_DIALECT_REGISTRATION_H_
+
+#include "mlir/Dialect/StandardOps/IR/Ops.h"  // from @llvm-project
+#include "mlir/IR/Dialect.h"  // from @llvm-project
+#include "tensorflow/compiler/mlir/tensorflow/ir/tf_device.h"
+#include "tensorflow/compiler/mlir/tensorflow/ir/tf_executor.h"
+#include "tensorflow/compiler/mlir/tensorflow/ir/tf_ops.h"
+#include "tensorflow/compiler/mlir/tensorflow/ir/tf_saved_model.h"
+
+namespace mlir {
+// Inserts all the TensorFlow dialects in the provided registry. This is
+// intended for tools that need to register dialects before parsing .mlir files.
+inline void RegisterAllTensorFlowDialects(DialectRegistry &registry) {
+  registry.insert<mlir::StandardOpsDialect, mlir::TF::TensorFlowDialect,
+                  mlir::tf_device::TensorFlowDeviceDialect,
+                  mlir::tf_executor::TensorFlowExecutorDialect,
+                  mlir::tf_saved_model::TensorFlowSavedModelDialect>();
+}
+}  // namespace mlir
+
+#endif  // TENSORFLOW_COMPILER_MLIR_TENSORFLOW_DIALECT_REGISTRATION_H_