executorch-sys

For a general description of the project, see the the executorch crate.

Build

To build the library, you need to build the C++ library first. The C++ library allow for great flexibility with many flags, customizing which modules, kernels, and extensions are built. Multiple static libraries are built, and the Rust library links to them. In the following example we build the C++ library with the necessary flags to run example hello_world_add:

# Clone the C++ library
cd ${TEMP_DIR}
git clone --depth 1 --branch v0.4.0 https://github.com/pytorch/executorch.git
cd executorch
git submodule sync --recursive
git submodule update --init --recursive

# Install requirements
./install_requirements.sh

# Build C++ library
mkdir cmake-out && cd cmake-out
cmake \
    -DDEXECUTORCH_SELECT_OPS_LIST=aten::add.out \
    -DEXECUTORCH_BUILD_EXECUTOR_RUNNER=OFF \
    -DEXECUTORCH_BUILD_EXTENSION_RUNNER_UTIL=OFF \
    -DBUILD_EXECUTORCH_PORTABLE_OPS=ON \
    -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON \
    -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON \
    -DEXECUTORCH_ENABLE_PROGRAM_VERIFICATION=ON \
    -DEXECUTORCH_ENABLE_LOGGING=ON \
    ..
make -j

# Static libraries are in cmake-out/
# core:
#   cmake-out/libexecutorch.a
#   cmake-out/libexecutorch_no_prim_ops.a
# kernels implementations:
#   cmake-out/kernels/portable/libportable_ops_lib.a
#   cmake-out/kernels/portable/libportable_kernels.a
# extension data loader, enabled with EXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON:
#   cmake-out/extension/data_loader/libextension_data_loader.a
# extension module, enabled with EXECUTORCH_BUILD_EXTENSION_MODULE=ON:
#   cmake-out/extension/module/libextension_module_static.a

# Run example
# We set EXECUTORCH_RS_EXECUTORCH_LIB_DIR to the path of the C++ build output
cd ${EXECUTORCH_RS_DIR}/examples/hello_world_add
python export_model.py
EXECUTORCH_RS_EXECUTORCH_LIB_DIR=${TEMP_DIR}/executorch/cmake-out cargo run

The executorch crate will always look for the following static libraries:

• libexecutorch.a
• libexecutorch_no_prim_ops.a

Additional libs are required if feature flags are enabled (see next section):

• libextension_data_loader.a
• libextension_module_static.a

The static libraries of the kernels implementations are required only if your model uses them, and they should be linked manually by the binary that uses the executorch crate. For example, the hello_world_add example uses a model with a single addition operation, so it compile the C++ library with DEXECUTORCH_SELECT_OPS_LIST=aten::add.out and contain the following lines in its build.rs:

println!("cargo::rustc-link-lib=static:+whole-archive=portable_kernels");
println!("cargo::rustc-link-lib=static:+whole-archive=portable_ops_lib");

let libs_dir = std::env::var("EXECUTORCH_RS_EXECUTORCH_LIB_DIR").unwrap();
println!("cargo::rustc-link-search={}/kernels/portable/", libs_dir);

Note that the ops and kernels libs are linked with +whole-archive to ensure that all symbols are included in the binary.

Cargo Features

• data-loader

  Includes the FileDataLoader and MmapDataLoader structs. Without this feature the only available data loader is BufferDataLoader. The libextension_data_loader.a static library is required, compile C++ executorch with EXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON.

• module

  Includes the Module struct. The libextension_module_static.a static library is required, compile C++ executorch with EXECUTORCH_BUILD_EXTENSION_MODULE=ON. Also includes the std feature.

• std

  Enable the standard library. This feature is enabled by default, but can be disabled to build executorch in a no_std environment. NOTE: no_std is still WIP, see https://github.com/pytorch/executorch/issues/4561

By default the std feature is enabled.