Will cmake compiled TFLite work on android?

Question

I'm making a project with 2 variations, a desktop version and an android version. Both of them are using the same c++ code base. I want to use TFLite without getting into any android configuration like gradle or an aar file. I just want a pure .so file that my c++ can use thus android can through ndk. I know there are some complications like ndk using clang and requiring arm64 architecture, but I think it should be possible. Note that my project requires ndk version 22 and above.

Here is how I configured tflite for my desktop/debian project:

1. On ~/Desktop/ I ran git clone https://github.com/tensorflow/tensorflow.git tensorflow_src
2. mkdir tflite_build & cd ~/Desktop/tflite_build
3. cmake ../tensorflow_src/tensorflow/lite
4. cmake --build . I've removed the -J flag regardless of what the docs says because it causes my pc to freeze.
5. mkdir ~/Desktop/tf_test & cd ~/Desktop/tf_test
6. Create a CMakeLists.txt and a main.cpp file inside tf_testdirectory.
7. Put the main code from the minimal example on the github repo provided above then this code in CMake:

cmake_minimum_required(VERSION 3.16)
project(minimal C CXX)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DTFLITE_DISABLE_TELEMETRY=1")

set(TENSORFLOW_SOURCE_DIR "" CACHE PATH
  "Directory that contains the TensorFlow project" )
if(NOT TENSORFLOW_SOURCE_DIR)
  get_filename_component(TENSORFLOW_SOURCE_DIR
    "/home/user/Desktop/tensorflow_src" ABSOLUTE)
endif()

add_subdirectory(
  "${TENSORFLOW_SOURCE_DIR}/tensorflow/lite"
  "${CMAKE_CURRENT_BINARY_DIR}/tensorflow-lite" EXCLUDE_FROM_ALL)

add_executable(minimal minimal.cc)
target_link_libraries(minimal tensorflow-lite)

8. Created the folder tf_Test/build and ran cmake .. inside it.
9. After cmake is completed I run make inside the build directory

This works just fine on debian. However when I try to add this to my cmake on my android ndk project, connect my tablet and run the project I get all these errors:

...
- Looking for strtoull_l - found
-- Using toolchain file: /home/user/Android/Sdk/ndk/25.0.8775105/build/cmake/android.toolchain.cmake.
-- CMAKE_CXX_FLAGS: -g -DANDROID -fdata-sections -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security  -frtti -fexceptions -fvisibility=hidden -std=c++17 -O0 -Wall -Wextra -Wshadow -Wnon-virtual-dtor -pthread -frtti -fexceptions
-- Found Python3: /usr/bin/python3.9 (found suitable version "3.9.2", minimum required is "3.5") found components: Interpreter 
-- Downloading pthreadpool to /home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/pthreadpool-source (define PTHREADPOOL_SOURCE_DIR to avoid it)
-- Configuring incomplete, errors occurred!
See also "/home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/pthreadpool-download/CMakeFiles/CMakeOutput.log".
-- The ASM compiler identification is Clang with GNU-like command-line
-- Found assembler: /home/user/Android/Sdk/ndk/25.0.8775105/toolchains/llvm/prebuilt/linux-x86_64/bin/clang
-- Downloading FP16 to /home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/FP16-source (define FP16_SOURCE_DIR to avoid it)
-- Configuring incomplete, errors occurred!
See also "/home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/FP16-download/CMakeFiles/CMakeOutput.log".
-- Downloading FXdiv to /home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/FXdiv-source (define FXDIV_SOURCE_DIR to avoid it)
-- Configuring incomplete, errors occurred!
See also "/home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/FXdiv-download/CMakeFiles/CMakeOutput.log".
-- RUY is enabled.
-- Configuring incomplete, errors occurred!
See also "/home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/CMakeFiles/CMakeOutput.log".
See also "/home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/CMakeFiles/CMakeError.log".

CMake Warning at /home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/abseil-cpp/CMakeLists.txt:70 (message):
  A future Abseil release will default ABSL_PROPAGATE_CXX_STD to ON for CMake
  3.8 and up.  We recommend enabling this option to ensure your project still
  builds correctly.


CMake Error: CMake was unable to find a build program corresponding to "Ninja".  CMAKE_MAKE_PROGRAM is not set.  You probably need to select a different build tool.
No such file or directory
CMake Error: Generator: execution of make failed. Make command was:  && 
CMake Error at /home/user/Desktop/official_stuff/tensorflow_src/tensorflow/lite/CMakeLists.txt:167 (add_subdirectory):
  add_subdirectory given source
  "/home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/pthreadpool-source"
  which is not an existing directory.


CMake Error: CMake was unable to find a build program corresponding to "Ninja".  CMAKE_MAKE_PROGRAM is not set.  You probably need to select a different build tool.
No such file or directory
CMake Error: Generator: execution of make failed. Make command was:  && 
CMake Error: CMake was unable to find a build program corresponding to "Ninja".  CMAKE_MAKE_PROGRAM is not set.  You probably need to select a different build tool.
No such file or directory
CMake Error: Generator: execution of make failed. Make command was:  && 
CMake Error at /home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/xnnpack/CMakeLists.txt:844 (ADD_SUBDIRECTORY):
  ADD_SUBDIRECTORY given source
  "/home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/pthreadpool-source"
  which is not an existing directory.


CMake Error at /home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/xnnpack/CMakeLists.txt:884 (ADD_SUBDIRECTORY):
  ADD_SUBDIRECTORY given source
  "/home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/FXdiv-source"
  which is not an existing directory.


CMake Error at /home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/xnnpack/CMakeLists.txt:908 (ADD_SUBDIRECTORY):
  ADD_SUBDIRECTORY given source
  "/home/user/Desktop/native/examples/android/app/.cxx/Debug/5c1w1z3w/arm64-v8a/FP16-source"
  which is not an existing directory.

What's the right way to approach this? Following the android build documentation on tflite's website causes a lot of problems.

Update: Installing ninja fixed almost all my problems, the only error I have now is:

In file included from /home/user/Desktop/official_stuff/tensorflow_src/tensorflow/lite/python/interpreter_wrapper/python_error_reporter.cc:16:
/home/user/Desktop/official_stuff/tensorflow_src/tensorflow/lite/python/interpreter_wrapper/python_error_reporter.h:19:10: fatal error: 'Python.h' file not found

python3 is in fact installed on my system, I used it on a c code before.

Update: Adding this to top of my cmake solved the python issue:

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -I/usr/include/python3.9 -I/usr/include/python3.9  -Wno-unused-result -Wsign-compare -g -ffile-prefix-map=/build/python3.9-RNBry6/python3.9-3.9.2=. -specs=/usr/share/dpkg/no-pie-compile.specs -fstack-protector -Wformat -Werror=format-security  -DNDEBUG -g -fwrapv -Wall")

Update: Now I get:

In file included from /home/user/Desktop/SmartAlpha/official_stuff/tensorflow_src/tensorflow/lite/python/interpreter_wrapper/numpy.cc:17:
In file included from /home/user/Desktop/SmartAlpha/official_stuff/tensorflow_src/tensorflow/lite/python/interpreter_wrapper/numpy.h:49:
In file included from /usr/include/python3.9/Python.h:8:
/usr/include/python3.9/pyconfig.h:9:12: fatal error: 'aarch64-linux-gnu/python3.9/pyconfig.h' file not found

Answer 1

LAST EDIT: You seem to completely overlook what I'm trying to explain you the whole time about different architectures. Your phone is not running on the same cpu architecture as your desktop. Your desktop machine is most likely running on amd64, while your phone is most likely arm64 which is also known as Aarch64 (do you now see what the latest error means? - It can't find the appropriate packages for the correct architecture - you can see that from the path in the error message).

You installed the amd64 package by issuing sudo apt-get install python-dev not the arm64 package. Check this official debian wiki on how to use MultiArch packages

You need to:

• Update your system so that it can download the packages for different architectures
• And sudo apt-get install python-dev:arm64

---

EDIT: Regarding the error in the updated question, you are most likely missing python development packages. Since you are on Debian I've looked for a possible package of interested and this might be it: python-dev, try to apt-get it for the correct architecture that you need and maybe it will resolve your issues.

---

1. Make sure that Ninja is installed. CMake is trying to use it - this confuses a lot of users as they most commonly use Makefiles and don't know that an alternative exists. I don't see you explicitly stating that you use CMake + Ninja and hence I mention it.

2. If you have Ninja installed then the issue is most likely caused by the fact that it can't resolve the path via just the executable name. Take a look at CMAKE_MAKE_PROGRAM to better understand what I mean.

If 2. is your issue then you can try and set the whole path to this CMAKE_MAKE_PROGRAM variable, i.e. set(CMAKE_MAKE_PROGRAM /absolute/path/to/bin/ninja) and see if resolves the issue.