Support for ESP32 with ESP-IDF

PiperOrigin-RevId: 277408790
Change-Id: Ie1cc9ab7149db89b93508d21e7bfe7be40422433

tensorflow/lite/experimental/micro/examples/hello_world/README.md

@@ -67,6 +67,65 @@ wave graphically. To view it, go to `Tools -> Serial Plotter`. You will see one
 datapoint being logged for each inference cycle, expressed as a number between 0
 and 255.
 
+## Deploy to ESP32
+
+The following instructions will help you build and deploy this sample
+to [ESP32](https://www.espressif.com/en/products/hardware/esp32/overview)
+devices using the [ESP IDF](https://github.com/espressif/esp-idf).
+
+The sample has been tested on ESP-IDF version 4.0 with the following devices:
+- [ESP32-DevKitC](http://esp-idf.readthedocs.io/en/latest/get-started/get-started-devkitc.html)
+- [ESP-EYE](https://github.com/espressif/esp-who/blob/master/docs/en/get-started/ESP-EYE_Getting_Started_Guide.md)
+
+### Install the ESP IDF
+
+Follow the instructions of the
+[ESP-IDF get started guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html)
+to setup the toolchain and the ESP-IDF itself.
+
+The next steps assume that the
+[IDF environment variables are set](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html#step-4-set-up-the-environment-variables) :
+
+ * The `IDF_PATH` environment variable is set
+ * `idf.py` and Xtensa-esp32 tools (e.g. `xtensa-esp32-elf-gcc`) are in `$PATH`
+
+### Generate the examples
+The example project can be generated with the following command:
+```
+make -f tensorflow/lite/experimental/micro/tools/make/Makefile TARGET=esp generate_hello_world_esp_project
+```
+
+### Building the example
+
+Go the the example project directory
+```
+cd tensorflow/lite/experimental/micro/tools/make/gen/esp_xtensa-esp32/prj/hello_world/esp-idf
+```
+
+Then build with `idf.py`
+```
+idf.py build
+```
+
+### Load and run the example
+
+To flash (replace `/dev/ttyUSB0` with the device serial port):
+```
+idf.py --port /dev/ttyUSB0 flash
+```
+
+Monitor the serial output:
+```
+idf.py --port /dev/ttyUSB0 monitor
+```
+
+Use `Ctrl+]` to exit.
+
+The previous two commands can be combined:
+```
+idf.py --port /dev/ttyUSB0 flash monitor
+```
+
 ## Deploy to SparkFun Edge
 
 The following instructions will help you build and deploy this sample on the

tensorflow/lite/experimental/micro/examples/hello_world/esp/main.cc

@@ -0,0 +1,23 @@
+/* Copyright 2019 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.
+==============================================================================*/
+
+#include "tensorflow/lite/experimental/micro/examples/hello_world/main_functions.h"
+
+extern "C" void app_main(void) {
+  setup();
+  while (true) {
+    loop();
+  }
+}

tensorflow/lite/experimental/micro/tools/make/Makefile

@@ -184,6 +184,12 @@ KEIL_PROJECT_FILES := \
 ARDUINO_PROJECT_FILES := \
   library.properties
 
+ESP_PROJECT_FILES := \
+  README_ESP.md \
+  CMakeLists.txt \
+  main/CMakeLists.txt \
+  components/tfmicro/CMakeLists.txt
+
 ALL_PROJECT_TARGETS :=
 
 ARDUINO_LIBRARY_TARGETS :=

tensorflow/lite/experimental/micro/tools/make/helper_functions.inc

@@ -112,33 +112,38 @@ define generate_arduino_project
 
 $(PRJDIR)$(2)/arduino/examples/%.cpp: tensorflow/lite/experimental/micro/examples/%.cc
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --is_example_source \
         --source_path="$$<" \
         --third_party_headers="$(4)" < $$< > $$@
 
 $(PRJDIR)$(2)/arduino/examples/%.h: tensorflow/lite/experimental/micro/examples/%.h
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --is_example_source \
         --source_path="$$<" \
         --third_party_headers="$(4)" < $$< > $$@
 
 $(PRJDIR)$(2)/arduino/examples/%/main.ino: tensorflow/lite/experimental/micro/examples/%/main_functions.cc
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --is_example_ino \
         --source_path="$$<" \
         --third_party_headers="$(4)" < $$< > $$@
 
 $(PRJDIR)$(2)/arduino/src/%.cpp: %.cc
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --third_party_headers="$(4)" < $$< > $$@
 
 $(PRJDIR)$(2)/arduino/src/%.h: %.h third_party_downloads
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --third_party_headers="$(4)" < $$< > $$@
 
 $(PRJDIR)$(2)/arduino/LICENSE: LICENSE
@@ -147,28 +152,33 @@ $(PRJDIR)$(2)/arduino/LICENSE: LICENSE
 
 $(PRJDIR)$(2)/arduino/src/%: % third_party_downloads
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --third_party_headers="$(4)" < $$< > $$@
 
 $(PRJDIR)$(2)/arduino/src/third_party/%: tensorflow/lite/experimental/micro/tools/make/downloads/% third_party_downloads
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --third_party_headers="$(4)" < $$< > $$@
 
 $(PRJDIR)$(2)/arduino/src/third_party/%.cpp: tensorflow/lite/experimental/micro/tools/make/downloads/%.cc third_party_downloads
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --third_party_headers="$(4)" < $$< > $$@
 
 $(PRJDIR)$(2)/arduino/src/third_party/flatbuffers/include/flatbuffers/base.h: tensorflow/lite/experimental/micro/tools/make/downloads/flatbuffers/include/flatbuffers/base.h third_party_downloads
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --third_party_headers="$(4)" < $$< | \
         sed -E 's/utility\.h/utility/g' > $$@
 
 $(PRJDIR)$(2)/arduino/src/third_party/kissfft/kiss_fft.h: tensorflow/lite/experimental/micro/tools/make/downloads/kissfft/kiss_fft.h third_party_downloads
 	@mkdir -p $$(dir $$@)
-	@python tensorflow/lite/experimental/micro/tools/make/transform_arduino_source.py \
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=arduino \
         --third_party_headers="$(4)" < $$< | \
         sed -E 's@#include <string.h>@//#include <string.h> /* Patched by helper_functions.inc for Arduino compatibility */@g' > $$@
 
@@ -217,6 +227,67 @@ ALL_PROJECT_TARGETS += $(if $(findstring _test,$(2)),,generate_$(2)_arduino_libr
 
 endef
 
+# Creates a set of rules to build a standalone ESP-IDF project for an
+# executable, including all of the source and header files required in a
+# separate folder.
+# Arguments are:
+# 1 - Project file template names.
+# 2 - Name of executable.
+# 3 - List of C/C++ source files needed to build the TF Micro component.
+# 4 - List of C/C++ header files needed to build the TF Micro component.
+# 5 - List of C/C++ source files needed to build this particular project.
+# 6 - List of C/C++ header files needed to build this particular project.
+# 7 - Linker flags required.
+# 8 - C++ compilation flags needed.
+# 9 - C compilation flags needed.
+# 10 - List of includes.
+define generate_esp_project
+$(PRJDIR)$(2)/esp-idf/LICENSE: LICENSE
+	@mkdir -p $$(dir $$@)
+	@cp $$< $$@
+
+$(PRJDIR)$(2)/esp-idf/main/%.cc: tensorflow/lite/experimental/micro/examples/$(2)/%.cc
+	@mkdir -p $$(dir $$@)
+	@python tensorflow/lite/experimental/micro/tools/make/transform_source.py \
+        --platform=esp \
+        --is_example_source \
+        --source_path="$$<" \
+        < $$< > $$@
+
+$(PRJDIR)$(2)/esp-idf/main/%: tensorflow/lite/experimental/micro/examples/$(2)/%
+	@mkdir -p $$(dir $$@)
+	@cp $$< $$@
+
+$(PRJDIR)$(2)/esp-idf/components/tfmicro/%: % third_party_downloads
+	@mkdir -p $$(dir $$@)
+	@cp $$< $$@
+
+$(PRJDIR)$(2)/esp-idf/components/tfmicro/third_party/%: tensorflow/lite/experimental/micro/tools/make/downloads/% third_party_downloads
+	@mkdir -p $$(dir $$@)
+	@cp $$< $$@
+
+$(PRJDIR)$(2)/esp-idf/%: tensorflow/lite/experimental/micro/tools/make/templates/esp/%.tpl
+	$(eval MAIN_SRCS_RELATIVE := $(patsubst tensorflow/lite/experimental/micro/examples/$(2)/%,%,$(5)))
+
+	@mkdir -p $$(dir $$@)
+	@sed -E 's#\%\{COMPONENT_SRCS\}\%#$(3)#g' $$< | \
+	sed -E 's#\%\{MAIN_SRCS\}\%#$(MAIN_SRCS_RELATIVE)#g' | \
+	sed -E 's#\%\{EXECUTABLE\}\%#$(2)#g' | \
+	sed -E 's#\%\{COMPONENT_INCLUDES\}\%#$(10)#g' | \
+	sed -E 's#\%\{LINKER_FLAGS\}\%#$(7)#g' | \
+	sed -E 's#\%\{CXX_FLAGS\}\%#$(8)#g' | \
+	sed -E 's#\%\{CC_FLAGS\}\%#$(9)#g' > $$@
+
+generate_$(2)_esp_project: \
+$(addprefix $(PRJDIR)$(2)/esp-idf/,\
+$(patsubst tensorflow/%,components/tfmicro/tensorflow/%,\
+$(patsubst third_party/%,components/tfmicro/third_party/%,\
+$(patsubst tensorflow/lite/experimental/micro/examples/$(2)/%,main/%,$(3) $(4) $(5) $(6))))) \
+$(addprefix $(PRJDIR)$(2)/esp-idf/,$(1))
+
+ALL_PROJECT_TARGETS += generate_$(2)_esp_project
+endef
+
 # Specialized version of generate_project for TF Lite Micro test targets that
 # automatically includes standard library files, so you just need to pass the
 # test name and any extra source files required.
@@ -231,6 +302,7 @@ $(call generate_project,make,$(MAKE_PROJECT_FILES),$(1),$(MICROLITE_CC_SRCS) $(T
 $(call generate_project,mbed,$(MBED_PROJECT_FILES),$(1),$(MICROLITE_CC_SRCS) $(THIRD_PARTY_CC_SRCS) $(2),$(MICROLITE_CC_HDRS) $(THIRD_PARTY_CC_HDRS) $(MICROLITE_TEST_HDRS) $(3),$(MICROLITE_LIBS),$(CXXFLAGS),$(CCFLAGS))
 $(call generate_project,keil,$(KEIL_PROJECT_FILES),$(1),$(MICROLITE_CC_SRCS) $(THIRD_PARTY_CC_SRCS) $(2),$(MICROLITE_CC_HDRS) $(THIRD_PARTY_CC_HDRS) $(MICROLITE_TEST_HDRS) $(3),$(MICROLITE_LIBS),$(CXXFLAGS),$(CCFLAGS))
 $(call generate_arduino_project,$(ARDUINO_PROJECT_FILES),$(1),$(MICROLITE_CC_SRCS) $(THIRD_PARTY_CC_SRCS) $(2),$(MICROLITE_CC_HDRS) $(THIRD_PARTY_CC_HDRS) $(MICROLITE_TEST_HDRS) $(3),$(MICROLITE_LIBS),$(CXXFLAGS),$(CCFLAGS))
+$(call generate_esp_project,$(ESP_PROJECT_FILES),$(1),$(MICROLITE_CC_SRCS) $(THIRD_PARTY_CC_SRCS),$(MICROLITE_CC_HDRS) $(THIRD_PARTY_CC_HDRS) $(MICROLITE_TEST_HDRS),$(2),$(3),$(MICROLITE_LIBS),$(CXXFLAGS),$(CCFLAGS),$(PROJECT_INCLUDES))
 endef
 
 # Handles the details of generating a binary target, including specializing

tensorflow/lite/experimental/micro/tools/make/targets/esp32_makefile.inc

@@ -0,0 +1,5 @@
+# Settings for Espressif ESP32
+
+ifeq ($(TARGET), esp)
+  TARGET_ARCH := xtensa-esp32
+endif

tensorflow/lite/experimental/micro/tools/make/templates/esp/CMakeLists.txt.tpl

@@ -0,0 +1,3 @@
+cmake_minimum_required(VERSION 3.5)
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(%{EXECUTABLE}%)

tensorflow/lite/experimental/micro/tools/make/templates/esp/README_ESP.md.tpl

@@ -0,0 +1,58 @@
+# TensorFlow Lite Micro ESP-IDF Project
+
+This folder has been autogenerated by TensorFlow, and contains source, header,
+and project files needed to build a single TensorFlow Lite Micro target using
+Espressif's [ESP-IDF](https://docs.espressif.com/projects/esp-idf/en/latest/).
+
+## Usage
+
+### Install the ESP IDF
+
+Follow the instructions of the
+[ESP-IDF get started guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html)
+to setup the toolchain and the ESP-IDF itself.
+
+The next steps assume that the
+[IDF environment variables are set](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html#step-4-set-up-the-environment-variables) :
+ * The `IDF_PATH` environment variable is set.
+ * `idf.py` and Xtensa-esp32 tools (e.g., `xtensa-esp32-elf-gcc`) are in `$PATH`.
+
+## Build the example
+
+To build this, run:
+
+```
+idf.py build
+```
+
+### Load and run the example
+
+To flash (replace `/dev/ttyUSB0` with the device serial port):
+```
+idf.py --port /dev/ttyUSB0 flash
+```
+
+Monitor the serial output:
+```
+idf.py --port /dev/ttyUSB0 monitor
+```
+
+Use `Ctrl+]` to exit.
+
+The previous two commands can be combined:
+```
+idf.py --port /dev/ttyUSB0 flash monitor
+```
+
+## Project Generation
+
+See
+[tensorflow/lite/experimental/micro](https://github.com/tensorflow/tensorflow/tree/master/tensorflow/lite/experimental/micro)
+for details on how projects like this can be generated from the main source
+tree.
+
+## License
+
+TensorFlow's code is covered by the Apache2 License included in the repository,
+and third party dependencies are covered by their respective licenses, in the
+third_party folder of this package.

tensorflow/lite/experimental/micro/tools/make/templates/esp/components/tfmicro/CMakeLists.txt.tpl

@@ -0,0 +1,38 @@
+
+# Copyright 2019 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.
+
+#
+# This component was generated for the '%{EXECUTABLE}%' TF Micro example.
+#
+
+# Make sure that the IDF Path environment variable is defined
+if(NOT DEFINED ENV{IDF_PATH})
+  message(FATAL_ERROR "The IDF_PATH environment variable must point to the location of the ESP-IDF.")
+endif()
+
+idf_component_register(
+  SRCS %{COMPONENT_SRCS}%
+  INCLUDE_DIRS %{COMPONENT_INCLUDES}%)
+
+# Reduce the level of paranoia to be able to compile TF sources
+target_compile_options(${COMPONENT_LIB} PRIVATE
+  -Wno-maybe-uninitialized
+  -Wno-missing-field-initializers
+  -Wno-pointer-sign
+  -Wno-type-limits)
+
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} %{CC_FLAGS}%")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} %{CXX_FLAGS}%")
+set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} %{LINKER_FLAGS}%")

tensorflow/lite/experimental/micro/tools/make/templates/esp/main/CMakeLists.txt.tpl

@@ -0,0 +1,8 @@
+
+#
+# Main component of TF Micro project '%{EXECUTABLE}%'.
+#
+
+idf_component_register(
+    SRCS %{MAIN_SRCS}%
+    INCLUDE_DIRS "")

tensorflow/lite/experimental/micro/tools/make/transform_arduino_source_test.sh

@@ -37,7 +37,8 @@ EOF
 OUTPUT_REGULAR_FILE=${TEST_TMPDIR}/output_regular.cc
 THIRD_PARTY_HEADERS="subdir/foo.h subdir_2/include/bar/fish.h subdir_3/something.h"
 
-${TEST_SRCDIR}/tensorflow/lite/experimental/micro/tools/make/transform_arduino_source \
+${TEST_SRCDIR}/tensorflow/lite/experimental/micro/tools/make/transform_source \
+  --platform=arduino \
   --third_party_headers="${THIRD_PARTY_HEADERS}" \
   < ${INPUT_REGULAR_FILE} \
   > ${OUTPUT_REGULAR_FILE}
@@ -89,7 +90,8 @@ EOF
 
 OUTPUT_EXAMPLE_INO_FILE=${TEST_TMPDIR}/output_regular.cc
 
-${TEST_SRCDIR}/tensorflow/lite/experimental/micro/tools/make/transform_arduino_source \
+${TEST_SRCDIR}/tensorflow/lite/experimental/micro/tools/make/transform_source \
+  --platform=arduino \
   --third_party_headers="${THIRD_PARTY_HEADERS}" \
   --is_example_ino \
   < ${INPUT_EXAMPLE_INO_FILE} \
@@ -129,7 +131,8 @@ EOF
 
 OUTPUT_EXAMPLE_SOURCE_FILE=${TEST_TMPDIR}/output_example_source.h
 
-${TEST_SRCDIR}/tensorflow/lite/experimental/micro/tools/make/transform_arduino_source \
+${TEST_SRCDIR}/tensorflow/lite/experimental/micro/tools/make/transform_source \
+  --platform=arduino \
   --third_party_headers="${THIRD_PARTY_HEADERS}" \
   --is_example_source \
   --source_path="foo/input_example_source.h" \

tensorflow/lite/experimental/micro/tools/make/transform_esp_source_test.sh

@@ -0,0 +1,108 @@
+#!/bin/bash
+# Copyright 2019 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.
+# ==============================================================================
+#
+# Bash unit tests for the TensorFlow Lite Micro project generator.
+
+set -e
+
+INPUT_EXAMPLE_FILE=${TEST_TMPDIR}/input_example.cc
+cat << EOF > ${INPUT_EXAMPLE_FILE}
+#include <stdio.h>
+#include "baz.h"
+#include "tensorflow/lite/experimental/micro/examples/something/foo/fish.h"
+
+main() {
+  fprintf(stderr, "Hello World!\n");
+  return 0;
+}
+EOF
+
+OUTPUT_EXAMPLE_FILE=${TEST_TMPDIR}/output_example.cc
+
+${TEST_SRCDIR}/tensorflow/lite/experimental/micro/tools/make/transform_source \
+  --platform=esp \
+  --is_example_source \
+  --source_path="tensorflow/lite/experimental/micro/examples/something/input_example.cc" \
+  < ${INPUT_EXAMPLE_FILE} \
+  > ${OUTPUT_EXAMPLE_FILE}
+
+if ! grep -q '#include <stdio.h>' ${OUTPUT_EXAMPLE_FILE}; then
+  echo "ERROR: No stdio.h include found in output '${OUTPUT_EXAMPLE_FILE}'"
+  exit 1
+fi
+
+if ! grep -q '#include "baz.h"' ${OUTPUT_EXAMPLE_FILE}; then
+  echo "ERROR: No baz.h include found in output '${OUTPUT_EXAMPLE_FILE}'"
+  exit 1
+fi
+
+if ! grep -q '#include "foo/fish.h"' ${OUTPUT_EXAMPLE_FILE}; then
+  echo "ERROR: No foo/fish.h include found in output '${OUTPUT_EXAMPLE_FILE}'"
+  exit 1
+fi
+
+
+#
+# Example file in a sub directory.
+#
+
+mkdir -p "${TEST_TMPDIR}/subdir"
+INPUT_EXAMPLE_SUBDIR_FILE=${TEST_TMPDIR}/subdir/input_example.cc
+cat << EOF > ${INPUT_EXAMPLE_SUBDIR_FILE}
+#include <stdio.h>
+#include "baz.h"
+#include "tensorflow/lite/experimental/micro/examples/something/subdir/input_example.h"
+#include "tensorflow/lite/experimental/micro/examples/something/bleh.h"
+#include "tensorflow/lite/experimental/micro/examples/something/foo/fish.h"
+EOF
+
+OUTPUT_EXAMPLE_SUBDIR_FILE=${TEST_TMPDIR}/output_example.cc
+
+${TEST_SRCDIR}/tensorflow/lite/experimental/micro/tools/make/transform_source \
+  --platform=esp \
+  --is_example_source \
+  --source_path="tensorflow/lite/experimental/micro/examples/something/subdir/input_example.cc" \
+  < ${INPUT_EXAMPLE_SUBDIR_FILE} \
+  > ${OUTPUT_EXAMPLE_SUBDIR_FILE}
+
+if ! grep -q '#include <stdio.h>' ${OUTPUT_EXAMPLE_SUBDIR_FILE}; then
+  echo "ERROR: No stdio.h include found in output '${OUTPUT_EXAMPLE_SUBDIR_FILE}'"
+  exit 1
+fi
+
+if ! grep -q '#include "baz.h"' ${OUTPUT_EXAMPLE_SUBDIR_FILE}; then
+  echo "ERROR: No baz.h include found in output '${OUTPUT_EXAMPLE_SUBDIR_FILE}'"
+  exit 1
+fi
+
+if ! grep -q '#include "input_example.h"' ${OUTPUT_EXAMPLE_SUBDIR_FILE}; then
+  echo "ERROR: No input_example.h include found in output '${OUTPUT_EXAMPLE_SUBDIR_FILE}'"
+  cat ${OUTPUT_EXAMPLE_SUBDIR_FILE}
+  exit 1
+fi
+
+if ! grep -q '#include "../bleh.h"' ${OUTPUT_EXAMPLE_SUBDIR_FILE}; then
+  echo "ERROR: No ../bleh.h include found in output '${OUTPUT_EXAMPLE_SUBDIR_FILE}'"
+  exit 1
+fi
+
+if ! grep -q '#include "../foo/fish.h"' ${OUTPUT_EXAMPLE_SUBDIR_FILE}; then
+  echo "ERROR: No ../foo/fish.h include found in output '${OUTPUT_EXAMPLE_SUBDIR_FILE}'"
+  exit 1
+fi
+
+echo
+echo "SUCCESS: transform_esp_source test PASSED"

tensorflow/lite/experimental/micro/tools/make/transform_source.py

@@ -0,0 +1,204 @@
+# Lint as: python2, python3
+# Copyright 2019 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.
+# ==============================================================================
+"""Resolves non-system C/C++ includes to their full paths.
+
+Used to generate Arduino and ESP-IDF examples.
+"""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import argparse
+import os
+import re
+import sys
+import six
+
+
+EXAMPLE_DIR_PATH = 'tensorflow/lite/experimental/micro/examples/'
+
+
+def replace_arduino_includes(line, supplied_headers_list):
+  """Updates any includes to reference the new Arduino library paths."""
+  include_match = re.match(r'(.*#include.*")(.*)(")', line)
+  if include_match:
+    path = include_match.group(2)
+    for supplied_header in supplied_headers_list:
+      if six.ensure_str(supplied_header).endswith(path):
+        path = supplied_header
+        break
+    line = include_match.group(1) + six.ensure_str(path) + include_match.group(
+        3)
+  return line
+
+
+def replace_arduino_main(line):
+  """Updates any occurences of a bare main definition to the Arduino equivalent."""
+  main_match = re.match(r'(.*int )(main)(\(.*)', line)
+  if main_match:
+    line = main_match.group(1) + 'tflite_micro_main' + main_match.group(3)
+  return line
+
+
+def check_ino_functions(input_text):
+  """Ensures the required functions exist."""
+  # We're moving to an Arduino-friendly structure for all our examples, so they
+  # have to have a setup() and loop() function, just like their IDE expects.
+  if not re.search(r'void setup\(\) \{', input_text):
+    raise Exception(
+        'All examples must have a setup() function for Arduino compatiblity\n' +
+        input_text)
+  if not re.search(r'void loop\(\) \{', input_text):
+    raise Exception(
+        'All examples must have a loop() function for Arduino compatiblity')
+  return input_text
+
+
+def add_example_ino_library_include(input_text):
+  """Makes sure the example includes the header that loads the library."""
+  return re.sub(r'#include ', '#include <TensorFlowLite.h>\n\n#include ',
+                input_text, 1)
+
+
+def replace_ardunio_example_includes(line, _):
+  """Updates any includes for local example files."""
+  # Because the export process moves the example source and header files out of
+  # their default locations into the top-level 'examples' folder in the Arduino
+  # library, we have to update any include references to match.
+  dir_path = 'tensorflow/lite/experimental/micro/examples/'
+  include_match = re.match(
+      r'(.*#include.*")' + six.ensure_str(dir_path) + r'([^/]+)/(.*")', line)
+  if include_match:
+    flattened_name = re.sub(r'/', '_', include_match.group(3))
+    line = include_match.group(1) + flattened_name
+  return line
+
+
+def replace_esp_example_includes(line, source_path):
+  """Updates any includes for local example files."""
+  # Because the export process moves the example source and header files out of
+  # their default locations into the top-level 'main' folder in the ESP-IDF
+  # project, we have to update any include references to match.
+  include_match = re.match(r'.*#include.*"(' + EXAMPLE_DIR_PATH + r'.*)"', line)
+
+  if include_match:
+    # Compute the target path relative from the source's directory
+    target_path = include_match.group(1)
+    source_dirname = os.path.dirname(source_path)
+    rel_to_target = os.path.relpath(target_path, start=source_dirname)
+
+    line = '#include "%s"' % rel_to_target
+  return line
+
+
+def transform_arduino_sources(input_lines, flags):
+  """Transform sources for the Arduino platform.
+
+  Args:
+    input_lines: A sequence of lines from the input file to process.
+    flags: Flags indicating which transformation(s) to apply.
+
+  Returns:
+    The transformed output as a string.
+  """
+  supplied_headers_list = six.ensure_str(flags.third_party_headers).split(' ')
+
+  output_lines = []
+  for line in input_lines:
+    line = replace_arduino_includes(line, supplied_headers_list)
+    if flags.is_example_ino or flags.is_example_source:
+      line = replace_ardunio_example_includes(line, flags.source_path)
+    else:
+      line = replace_arduino_main(line)
+    output_lines.append(line)
+  output_text = '\n'.join(output_lines)
+
+  if flags.is_example_ino:
+    output_text = check_ino_functions(output_text)
+    output_text = add_example_ino_library_include(output_text)
+
+  return output_text
+
+
+def transform_esp_sources(input_lines, flags):
+  """Transform sources for the ESP-IDF platform.
+
+  Args:
+    input_lines: A sequence of lines from the input file to process.
+    flags: Flags indicating which transformation(s) to apply.
+
+  Returns:
+    The transformed output as a string.
+  """
+  output_lines = []
+  for line in input_lines:
+    if flags.is_example_source:
+      line = replace_esp_example_includes(line, flags.source_path)
+    output_lines.append(line)
+
+  output_text = '\n'.join(output_lines)
+  return output_text
+
+
+def main(unused_args, flags):
+  """Transforms the input source file to work when exported as example."""
+  input_file_lines = sys.stdin.read().split('\n')
+
+  output_text = ''
+  if flags.platform == 'arduino':
+    output_text = transform_arduino_sources(input_file_lines, flags)
+  elif flags.platform == 'esp':
+    output_text = transform_esp_sources(input_file_lines, flags)
+
+  sys.stdout.write(output_text)
+
+
+def parse_args():
+  """Converts the raw arguments into accessible flags."""
+  parser = argparse.ArgumentParser()
+  parser.add_argument(
+      '--platform',
+      choices=['arduino', 'esp'],
+      required=True,
+      help='Target platform.')
+  parser.add_argument(
+      '--third_party_headers',
+      type=str,
+      default='',
+      help='Space-separated list of headers to resolve.')
+  parser.add_argument(
+      '--is_example_ino',
+      dest='is_example_ino',
+      action='store_true',
+      help='Whether the destination is an example main ino.')
+  parser.add_argument(
+      '--is_example_source',
+      dest='is_example_source',
+      action='store_true',
+      help='Whether the destination is an example cpp or header file.')
+  parser.add_argument(
+      '--source_path',
+      type=str,
+      default='',
+      help='The relative path of the source code file.')
+  flags, unparsed = parser.parse_known_args()
+
+  main(unparsed, flags)
+
+
+if __name__ == '__main__':
+  parse_args()