Provide an extra arg to install_requirements to optionally build pybindings. (#2396)

Summary:
Pull Request resolved: #2396

bypass-github-export-checks

Reviewed By: kirklandsign

Differential Revision: D54840034

fbshipit-source-id: dc4b0e416ae7f093ff80bb336576b463eafd2b44

Author: shoumikhin

build/test_ios.sh

@@ -70,7 +70,7 @@ curl -LO "https://github.com/facebook/buck2/releases/download/$BUCK2_RELEASE_DAT
 zstd -cdq "$BUCK2_ARCHIVE" > "$BUCK2" && chmod +x "$BUCK2"
 rm "$BUCK2_ARCHIVE"
 
-./install_requirements.sh
+./install_requirements.sh --pybind coreml mps xnnpack
 export PATH="$(realpath third-party/flatbuffers/cmake-out):$PATH"
 ./build/install_flatc.sh
 
@@ -82,14 +82,6 @@ say "Installing MPS Backend Requirements"
 
 ./backends/apple/mps/install_requirements.sh
 
-say "Installing Python Bindings"
-
-EXECUTORCH_BUILD_PYBIND=ON \
-BUCK="$(pwd)/$BUCK2" \
-CMAKE_ARGS="-DEXECUTORCH_BUILD_COREML=ON -DEXECUTORCH_BUILD_MPS=ON -DEXECUTORCH_BUILD_XNNPACK=ON" \
-CMAKE_BUILD_PARALLEL_LEVEL=9 \
-pip install . --no-build-isolation -v
-
 say "Exporting Models"
 
 python3 -m examples.portable.scripts.export --model_name="$MODEL_NAME"

extension/pybindings/README.md

@@ -2,7 +2,30 @@
 This Python module, named `portable_lib`, provides a set of functions and classes for loading and executing bundled programs. To install it, run the fullowing command:
 
 ```bash
-EXECUTORCH_BUILD_PYBIND=ON pip install . --no-build-isolation
+EXECUTORCH_BUILD_PYBIND=ON \
+pip install . --no-build-isolation
+```
+
+Or when installing the rest of dependencies:
+
+```bash
+install_requirements.sh --pybind
+```
+
+# Link Backends
+
+You can link the runtime against some backends to make sure a delegated or partitioned model can still run by Python module successfully:
+
+```bash
+EXECUTORCH_BUILD_PYBIND=ON \
+CMAKE_ARGS="-DEXECUTORCH_BUILD_COREML=ON -DEXECUTORCH_BUILD_MPS=ON -DEXECUTORCH_BUILD_XNNPACK=ON" \
+pip install . --no-build-isolation
+```
+
+Similarly, when installing the rest of dependencies:
+
+```bash
+install_requirements.sh --pybind coreml mps xnnpack
 ```
 
 ## Functions

install_requirements.sh

@@ -17,6 +17,30 @@ then
   PYTHON_EXECUTABLE=python3
 fi
 
+# Parse options.
+EXECUTORCH_BUILD_PYBIND=OFF
+CMAKE_ARGS=""
+
+for arg in "$@"; do
+  case $arg in
+    --pybind)
+      EXECUTORCH_BUILD_PYBIND=ON
+      ;;
+    coreml|mps|xnnpack)
+      if [[ "$EXECUTORCH_BUILD_PYBIND" == "ON" ]]; then
+        CMAKE_ARGS="$CMAKE_ARGS -DEXECUTORCH_BUILD_${arg^^}=ON"
+      else
+        echo "Error: $arg must follow --pybind"
+        exit 1
+      fi
+      ;;
+    *)
+      echo "Error: Unknown option $arg"
+      exit 1
+      ;;
+  esac
+done
+
 # Install pytorch dependencies
 #
 # Note:
@@ -46,7 +70,10 @@ TORCHSR_VERSION=1.0.4
 pip install --pre torchsr==${TORCHSR_VERSION}
 
 # Install ExecuTorch after dependencies are installed.
-pip install . --no-build-isolation
+EXECUTORCH_BUILD_PYBIND="$EXECUTORCH_BUILD_PYBIND" \
+CMAKE_ARGS="$CMAKE_ARGS" \
+CMAKE_BUILD_PARALLEL_LEVEL=9 \
+pip install . --no-build-isolation -v
 
 # Install flatc dependency
 bash build/install_flatc.sh