Add bazel support to build nGraph (#434)

* Added bazel scripts for building libngraph_bridge.so and the INTERPRETER backend
* Added support for using the proper CXX ABI based on what is used to buld TensorFlow. Also upgraded the JSON library and fixed the interpreter build
* Fixed the example so that it works on CentOS. Also added the NDEBUG flag to ensure that the graph mods work.
* Fixed a makefile bug and updated the documentation
* Cleaned up and added a README for the bazel build setup
* Update README.md
* Update examples/tf_cpp_examples/README.md
* Added SDL flags and also updated based on PR comments

.gitignore

@@ -7,6 +7,9 @@ cpu_codegen/
 
 *.pbtxt
 *.dot
+*.whl
+*.bzl
+.bazelrc
 
 .*.swp
 .nfs*

README.md

@@ -53,7 +53,7 @@ TensorFlow model scripts and running them the usual way:
 
 Note: The version of the ngraph-tensorflow-bridge is not going to be exactly the same as when you build from source. This is due to delay in the source release and publishing the corresponding Python wheel. 
 
-### Option 2: Build nGraph bridge from source using TensorFlow source
+### Option 2: Build nGraph bridge from source
 
 To use the latest version, or to run unit tests, or if you are planning to contribute, install the nGraph 
 bridge using the TensorFlow source tree as follows: 

bazel/BUILD

@@ -0,0 +1,88 @@
+# ==============================================================================
+#  Copyright 2019 Intel Corporation
+#
+#  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.
+# ==============================================================================
+load("//:cxx_abi_option.bzl", "CXX_ABI")
+
+cc_binary(
+    name = 'libngraph_bridge.so',
+    srcs = [
+        "src/ngraph_api.cc",
+        "src/ngraph_api.h",
+        "src/ngraph_assign_clusters.cc",
+        "src/ngraph_assign_clusters.h",
+        "src/ngraph_builder.cc",
+        "src/ngraph_builder.h",
+        "src/ngraph_backend_manager.h",
+        "src/ngraph_backend_manager.cc",
+        "src/ngraph_capture_variables.cc",
+        "src/ngraph_capture_variables.h",
+        "src/ngraph_cluster_manager.cc",
+        "src/ngraph_cluster_manager.h",
+        "src/ngraph_conversions.h",
+        "src/ngraph_deassign_clusters.cc",
+        "src/ngraph_deassign_clusters.h",
+        "src/ngraph_encapsulate_clusters.cc",
+        "src/ngraph_encapsulate_clusters.h",
+        "src/ngraph_encapsulate_op.cc",
+        "src/ngraph_freshness_tracker.cc",
+        "src/ngraph_freshness_tracker.h",
+        "src/ngraph_mark_for_clustering.cc",
+        "src/ngraph_mark_for_clustering.h",
+        "src/ngraph_rewrite_for_tracking.cc",
+        "src/ngraph_rewrite_for_tracking.h",
+        "src/ngraph_rewrite_pass.cc",
+        "src/ngraph_tracked_variable.cc",
+        "src/ngraph_utils.cc",
+        "src/ngraph_utils.h",
+        "src/ngraph_version_utils.h",
+        "src/tf_deadness_analysis.cc",
+        "src/tf_deadness_analysis.h",
+        "src/tf_graphcycles.cc",
+        "src/tf_graphcycles.h",
+        "src/version.h",
+        "src/version.cc",
+        "logging/ngraph_log.h",
+        "logging/ngraph_log.cc",
+        "logging/tf_graph_writer.h",
+        "logging/tf_graph_writer.cc",
+    ],
+    linkshared = 1,
+    deps = [
+        "@local_config_tf//:libtensorflow_framework",
+        "@local_config_tf//:tf_header_lib",
+        "@ngraph//:ngraph_headers",
+        "@ngraph//:ngraph_core",
+    ],
+    copts = [
+        "-pthread", 
+        "-std=c++11", 
+        "-D_FORTIFY_SOURCE=2",
+        "-Wformat",
+        "-Wformat-security",
+        "-Wformat",
+        "-fstack-protector-strong",
+        "-D NDEBUG",
+        '-D SHARED_LIB_PREFIX=\\"lib\\"',
+        '-D SHARED_LIB_SUFFIX=\\".so\\"',
+        "-I logging",
+        "-I external/ngraph/src",
+    ] + CXX_ABI,
+    linkopts = [
+        "-Wl,-z,noexecstack",
+        "-Wl,-z,relro",
+        "-Wl,-z,now",
+    ],
+    visibility = ["//visibility:public"],
+)

bazel/README.md

@@ -0,0 +1,45 @@
+# Build nGraph TensorFlow bridge using bazel
+
+This directory contains scripts necessary to build the nGraph TensorFlow bridge using `bazel`. 
+
+:warning: This is experimental and will change over time. 
+
+## Prerequisites
+
+Please ensure that bazel and Python is installed on your system and you are able to build TensorFlow from source (though not needed for building the bridge). Please see the [build preperation] for details.
+
+## Build C++ library
+
+Go to the ngraph-tf directory and execute these commands to build the C++ library for nGraph-TensorFlow bridge:
+
+        ./configure_bazel.sh
+        bazel build libngraph_bridge.so
+        bazel build @ngraph//:libinterpreter_backend.so   
+
+This will produce the following binary files:
+
+```
+    bazel-bin/libngraph_bridge.so
+    bazel-bin/external/ngraph/libinterpreter_backend.so
+```
+
+### How to use the C++ library
+
+The C++ library `libngraph_bridge.so` can be used with a TensorFlow C++ application as described in the examples/tf_cpp_examples ([TensorFlow C++ example]) directory. Basic steps are the following:
+
+1. Get a copy of the TensorFlow C++ library by building one. Use [Option 2] to build all the necessary libraries as described in the [TensorFlow C++ example]  
+
+2. Replace the `libngraph_bridge.so` built by this bazel script in the `build/artifacts/lib<64>` directory.
+
+3. Run `make` to relink and run the example as described in the [TensorFlow C++ example] document.
+
+**Note** Currently only the INTERPRETER backend may be built using bazel. However other backends built using cmake system is fully binary compatible with the bridge built with bazel based build system as described here.
+
+## Build the Python wheel
+
+Coming up soon. For now please use the cmake based build system described in the [main README]
+
+[build preperation]: ../README.md#prepare-the-build-environment
+[Option 2]: ../README.md#option-2-build-ngraph-bridge-from-source
+[TensorFlow C++ example]: ../examples/tf_cpp_examples/README.md
+[main README]: ../README.md

bazel/WORKSPACE

@@ -0,0 +1,44 @@
+# ==============================================================================
+#  Copyright 2019 Intel Corporation
+#
+#  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.
+# ==============================================================================
+
+workspace(name = "ngraph_bridge")
+load("//tf_configure:tf_configure.bzl", "tf_configure")
+
+tf_configure(
+    name = "local_config_tf",
+)
+
+new_http_archive(
+    name = "ngraph",
+    build_file = "bazel/ngraph.BUILD",
+    sha256 = "1efd0cae2bc8febe40863727fcadf7eecbf7724073c5ddd2c95c6db00dd70985",
+    strip_prefix = "ngraph-0.14.0-rc.1",
+    urls = [
+        "https://mirror.bazel.build/github.com/NervanaSystems/ngraph/archive/v0.14.0-rc.1.tar.gz",
+        "https://github.com/NervanaSystems/ngraph/archive/v0.14.0-rc.1.tar.gz",
+    ],
+)
+
+new_http_archive(
+    name = "nlohmann_json_lib",
+    build_file = "bazel/nlohmann_json.BUILD",
+    sha256 = "e0b1fc6cc6ca05706cce99118a87aca5248bd9db3113e703023d23f044995c1d",
+    strip_prefix = "json-3.5.0",
+    urls = [
+        "https://mirror.bazel.build/github.com/nlohmann/json/archive/v3.5.0.tar.gz",
+        "https://github.com/nlohmann/json/archive/v3.5.0.tar.gz",
+    ],
+)

bazel/ngraph.BUILD

@@ -0,0 +1,115 @@
+# ==============================================================================
+#  Copyright 2019 Intel Corporation
+#
+#  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.
+# ==============================================================================
+licenses(["notice"])  
+exports_files(["LICENSE"])
+
+load("@ngraph_bridge//:cxx_abi_option.bzl", "CXX_ABI")
+
+cc_library(
+    name = "ngraph_headers",
+    hdrs = glob(["src/ngraph/**/*.hpp"]),
+    visibility = ["//visibility:public"],
+)
+
+cc_library(
+    name = "ngraph_core",
+    srcs = glob([
+        "src/ngraph/*.cpp",
+        "src/ngraph/autodiff/*.cpp",
+        "src/ngraph/builder/*.cpp",
+        "src/ngraph/descriptor/*.cpp",
+        "src/ngraph/descriptor/layout/*.cpp",
+        "src/ngraph/op/*.cpp",
+        "src/ngraph/op/experimental/generate_mask.cpp",
+        "src/ngraph/op/experimental/quantized_avg_pool.cpp",
+        "src/ngraph/op/experimental/quantized_conv.cpp",
+        "src/ngraph/op/experimental/quantized_conv_bias.cpp",
+        "src/ngraph/op/experimental/quantized_conv_relu.cpp",
+        "src/ngraph/op/experimental/quantized_max_pool.cpp",
+        "src/ngraph/op/experimental/shape_of.cpp",
+        "src/ngraph/op/util/*.cpp",
+        "src/ngraph/pattern/*.cpp",
+        "src/ngraph/pattern/*.hpp",
+        "src/ngraph/pass/*.cpp",
+        "src/ngraph/pass/*.hpp",
+        "src/ngraph/runtime/*.cpp",
+        "src/ngraph/type/*.cpp",
+        ],
+        exclude = [
+        "src/ngraph/ngraph.cpp",
+    ]),
+    deps = [
+        ":ngraph_headers",
+        "@nlohmann_json_lib",
+    ],
+    copts = [
+        "-I external/ngraph/src",
+        "-I external/nlohmann_json_lib/include/",
+        "-D_FORTIFY_SOURCE=2",
+        "-Wformat",
+        "-Wformat-security",
+        "-Wformat",
+        "-fstack-protector-strong",
+        '-D SHARED_LIB_PREFIX=\\"lib\\"',
+        '-D SHARED_LIB_SUFFIX=\\".so\\"',
+        '-D NGRAPH_VERSION=\\"0.14.0-rc.1\\"',
+        "-D NGRAPH_DEX_ONLY",
+        '-D PROJECT_ROOT_DIR=\\"\\"',
+    ] + CXX_ABI,
+    linkopts = [
+        "-Wl,-z,noexecstack",
+        "-Wl,-z,relro",
+        "-Wl,-z,now",
+    ],
+    visibility = ["//visibility:public"],
+    alwayslink = 1,
+)
+
+cc_binary(
+    name = 'libinterpreter_backend.so',
+    srcs = glob([
+        "src/ngraph/except.hpp",
+        "src/ngraph/runtime/interpreter/*.cpp",
+        "src/ngraph/state/rng_state.cpp",
+    ]),
+    deps = [
+        ":ngraph_headers",
+        ":ngraph_core",
+    ],
+    copts = [
+        "-I external/ngraph/src",
+        "-I external/ngraph/src/ngraph",
+        "-I external/nlohmann_json_lib/include/",
+        "-D_FORTIFY_SOURCE=2",
+        "-Wformat",
+        "-Wformat-security",
+        "-Wformat",
+        "-fstack-protector-strong",
+        '-D SHARED_LIB_PREFIX=\\"lib\\"',
+        '-D SHARED_LIB_SUFFIX=\\".so\\"',
+        '-D NGRAPH_VERSION=\\"0.14.0-rc.1\\"',
+        "-D NGRAPH_DEX_ONLY",
+        '-D PROJECT_ROOT_DIR=\\"\\"',
+    ] + CXX_ABI,
+    linkopts = [
+        "-Wl,-z,noexecstack",
+        "-Wl,-z,relro",
+        "-Wl,-z,now",
+    ],
+    linkshared = 1,
+    visibility = ["//visibility:public"],
+)
+

bazel/nlohmann_json.BUILD

@@ -0,0 +1,31 @@
+# ==============================================================================
+#  Copyright 2019 Intel Corporation
+#
+#  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.
+# ==============================================================================
+licenses(["notice"]) 
+
+exports_files(["LICENSE.MIT"])
+load("@ngraph_bridge//:cxx_abi_option.bzl", "CXX_ABI")
+
+cc_library(
+    name = "nlohmann_json_lib",
+    hdrs = glob([
+        "include/nlohmann/**/*.hpp",
+    ]),
+    copts = [
+        "-I external/nlohmann_json_lib",
+    ]+ CXX_ABI,
+    visibility = ["//visibility:public"],
+    alwayslink = 1,
+)

bazel/tf_configure/BUILD.tpl

@@ -0,0 +1,18 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "tf_header_lib",
+    hdrs = [":tf_header_include"],
+    includes = ["include"],
+    visibility = ["//visibility:public"],
+)
+
+cc_library(
+    name = "libtensorflow_framework",
+    srcs = [":libtensorflow_framework.so"],
+    #data = ["lib/libtensorflow_framework.so"],
+    visibility = ["//visibility:public"],
+)
+
+%{TF_HEADER_GENRULE}
+%{TF_SHARED_LIBRARY_GENRULE}