remove buck2 from custom operator registration (#4233) (#4244)

Summary:
Pull Request resolved: #4233

For alpha+, we need to remove all buck2 commands and buck2 dependencies from static doc and github readmes.
This diff gets rid of the buck2 from  custom operator registration examples.

Reviewed By: larryliu0820

Differential Revision: D59661023

fbshipit-source-id: 25b4fec3f5ff71e615bc52b4b465d31a8e4c6c87
(cherry picked from commit 17ae009)

Co-authored-by: Songhao Jia <[email protected]>

Author: pytorchbot

examples/portable/custom_ops/README.md

@@ -1,4 +1,4 @@
-# Custom Operator Registration Examples (WIP)
+# Custom Operator Registration Examples
 This folder contains examples to register custom operators into PyTorch as well as register its kernels into ExecuTorch runtime.
 
 ## How to run
@@ -9,7 +9,7 @@ Run:
 
 ```bash
 cd executorch
-bash examples/portable/custom_ops/test_custom_ops.sh [cmake|buck2]
+bash examples/portable/custom_ops/test_custom_ops.sh
 ```
 
 ## AOT registration
@@ -37,24 +37,11 @@ After the model is exported by EXIR, we need C++ implementations of these custom
 ```
 For how to write these YAML entries, please refer to [`kernels/portable/README.md`](https://github.com/pytorch/executorch/blob/main/kernels/portable/README.md).
 
-Currently we provide 2 build systems that links `my_ops::mul3.out` kernel (written in `custom_ops_1.cpp`) to Executor runtime: buck2 and CMake. Both instructions are listed in `examples/portable/custom_ops/test_custom_ops.sh`(test_buck2_custom_op_1 and test_cmake_custom_op_1).
+Currently we use Cmake as the build system to link the `my_ops::mul3.out` kernel (written in `custom_ops_1.cpp`) to the ExecuTorch runtime. See instructions in: `examples/portable/custom_ops/test_custom_ops.sh` (test_cmake_custom_op_1).
 
 ## Selective build
 
-Note that we have defined a custom op for both `my_ops::mul3.out` and `my_ops::mul4.out` in `custom_ops.yaml`. Below is a demonstration of how to only register the operator from the model we are running into the runtime.
-
-In CMake, this is done by passing in a list of operators to `gen_oplist` custom rule: `--root_ops="my_ops::mul4.out"`.
-
-In Buck2, this is done by a rule called `et_operator_library`:
-```python
-et_operator_library(
-    name = "select_custom_ops_2",
-    ops = [
-        "my_ops::mul4.out",
-    ],
-...
-)
-```
+Note that we have defined a custom op for both `my_ops::mul3.out` and `my_ops::mul4.out` in `custom_ops.yaml`. To reduce binary size, we can choose to only register the operators used in the model. This is done by passing in a list of operators to the `gen_oplist` custom rule, for example: `--root_ops="my_ops::mul4.out"`.
 
 We then let the custom ops library depend on this target, to only register the ops we want.
 

examples/portable/custom_ops/test_custom_ops.sh

@@ -14,21 +14,6 @@ set -e
 # shellcheck source=/dev/null
 source "$(dirname "${BASH_SOURCE[0]}")/../../../.ci/scripts/utils.sh"
 
-test_buck2_custom_op_1() {
-  local model_name='custom_ops_1'
-  echo "Exporting ${model_name}.pte"
-  ${PYTHON_EXECUTABLE} -m "examples.portable.custom_ops.${model_name}"
-  # should save file custom_ops_1.pte
-
-  echo 'Running executor_runner'
-  $BUCK run //examples/portable/executor_runner:executor_runner \
-      --config=executorch.register_custom_op=1 -- --model_path="./${model_name}.pte"
-  # should give correct result
-
-  echo "Removing ${model_name}.pte"
-  rm "./${model_name}.pte"
-}
-
 test_cmake_custom_op_1() {
   local model_name='custom_ops_1'
   echo "Exporting ${model_name}.pte"
@@ -51,23 +36,6 @@ test_cmake_custom_op_1() {
   ${build_dir}/custom_ops_executor_runner --model_path="./${model_name}.pte"
 }
 
-test_buck2_custom_op_2() {
-  local model_name='custom_ops_2'
-
-  echo 'Building custom ops shared library'
-  SO_LIB=$($BUCK build //examples/portable/custom_ops:custom_ops_aot_lib_2 --show-output | grep "buck-out" | cut -d" " -f2)
-
-  echo "Exporting ${model_name}.pte"
-  ${PYTHON_EXECUTABLE} -m "examples.portable.custom_ops.${model_name}" --so_library="$SO_LIB"
-  # should save file custom_ops_2.pte
-
-  $BUCK run //examples/portable/executor_runner:executor_runner \
-      --config=executorch.register_custom_op=2 -- --model_path="./${model_name}.pte"
-  # should give correct result
-  echo "Removing ${model_name}.pte"
-  rm "./${model_name}.pte"
-}
-
 get_shared_lib_ext() {
   UNAME=$(uname)
   if [[ $UNAME == "Darwin" ]];
@@ -115,24 +83,6 @@ then
   PYTHON_EXECUTABLE=python3
 fi
 
-if [[ -z $BUCK ]];
-then
-  BUCK=buck2
-fi
-
-if [[ $1 == "cmake" ]];
-then
-  cmake_install_executorch_lib
-  test_cmake_custom_op_1
-  test_cmake_custom_op_2
-elif [[ $1 == "buck2" ]];
-then
-  test_buck2_custom_op_1
-  test_buck2_custom_op_2
-else
-  cmake_install_executorch_lib
-  test_cmake_custom_op_1
-  test_cmake_custom_op_2
-  test_buck2_custom_op_1
-  test_buck2_custom_op_2
-fi
+cmake_install_executorch_lib
+test_cmake_custom_op_1
+test_cmake_custom_op_2