[torchgen] Add CI job to cover custom ops registration for Executorch (#91291)

As titled. To register a custom op into Executorch, we need:

* `custom_ops.yaml`, defines the operator schema and the corresponding native function.
* `custom_ops.cpp`, defines the kernel.
* `RegisterDispatchKeyCustomOps.cpp`, a template to register operator into PyTorch.

Added a new test for custom ops. The custom op `custom::add_3.out` takes 3 tensors and add them together. The test makes sure it is registered correctly and then verifies the outcome is correct.

Differential Revision: [D42204263](https://our.internmc.facebook.com/intern/diff/D42204263/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91291
Approved by: https://github.com/ezyang

test/edge/CMakeLists.txt

@@ -14,11 +14,14 @@ set(GEN_COMMAND
         --aten_yaml_path=${TORCH_ROOT}/aten/src/ATen/native/native_functions.yaml
         --use_aten_lib
         --op_selection_yaml_path=${TEST_ROOT}/selected_operators.yaml
+        --custom_ops_yaml_path=${TEST_ROOT}/custom_ops.yaml
         )
 set(GEN_COMMAND_sources
         ${OUTPUT_DIRECTORY}/RegisterCodegenUnboxedKernelsEverything.cpp
+        ${OUTPUT_DIRECTORY}/RegisterCPUCustomOps.cpp
         ${OUTPUT_DIRECTORY}/Functions.h
         ${OUTPUT_DIRECTORY}/NativeFunctions.h
+        ${OUTPUT_DIRECTORY}/CustomOpsNativeFunctions.h
         )
 message(STATUS "Generating sources for unboxing kernels ${GEN_COMMAND}")
 add_custom_command(
@@ -32,6 +35,7 @@ add_custom_command(
         ${TEST_ROOT}/templates/Functions.h
         ${TEST_ROOT}/templates/NativeFunctions.h
         ${TEST_ROOT}/templates/RegisterCodegenUnboxedKernels.cpp
+        ${TEST_ROOT}/templates/RegisterDispatchKeyCustomOps.cpp
         WORKING_DIRECTORY ${TORCH_ROOT}
 )
 add_custom_target(unbox_target DEPENDS ${GEN_COMMAND_sources})
@@ -39,6 +43,7 @@ add_custom_target(unbox_target DEPENDS ${GEN_COMMAND_sources})
 add_library(unbox_lib STATIC
         ${GEN_COMMAND_sources}
         ${TEST_ROOT}/operator_registry.cpp
+        ${TEST_ROOT}/custom_ops.cpp
         )
 target_include_directories(unbox_lib PUBLIC ${TEST_ROOT} ${ATen_CPU_INCLUDE})
 target_link_libraries(unbox_lib PUBLIC torch_cpu)

test/edge/custom_ops.cpp

@@ -0,0 +1,10 @@
+#include <ATen/Tensor.h>
+
+namespace custom {
+namespace native {
+at::Tensor& add_3_out(const at::Tensor& a, const at::Tensor& b, const at::Tensor& c, at::Tensor& out) {
+    out = a.add(b).add(c);
+    return out;
+}
+}
+}

test/edge/custom_ops.yaml

@@ -0,0 +1,3 @@
+- func: custom::add_3.out(Tensor a, Tensor b, Tensor c, *, Tensor(a!) out) -> Tensor(a!)
+  dispatch:
+    CPU: custom::add_3_out

test/edge/selected_operators.yaml

@@ -448,3 +448,9 @@ operators:
     include_all_overloads: false
     is_root_operator: true
     is_used_for_training: true
+  custom::add_3.out:
+    debug_info:
+    - functions.yaml
+    include_all_overloads: false
+    is_root_operator: true
+    is_used_for_training: true

test/edge/templates/RegisterDispatchKeyCustomOps.cpp

@@ -0,0 +1,27 @@
+// clang-format off
+// Generated code for registering custom operators into the dispatcher.
+
+#include <torch/library.h>
+#include <ATen/Tensor.h>
+
+$ops_headers
+
+namespace torch {
+namespace executor {
+namespace function {
+
+
+${dispatch_anonymous_definitions}
+
+// All out variants ops
+${static_init_dispatch_registrations}
+
+namespace ${dispatch_namespace}
+{
+  ${dispatch_namespaced_definitions}
+
+} // namespace ${dispatch_namespace}
+
+} // namespace function
+} // namespace executor
+} // namespace torch

test/edge/templates/RegisterSchema.cpp

@@ -0,0 +1,10 @@
+// ${generated_comment}
+#define TORCH_ASSERT_ONLY_METHOD_OPERATORS
+#include <torch/library.h>
+
+namespace at {
+TORCH_LIBRARY_FRAGMENT(aten, m) {
+    ${aten_schema_registrations};
+}
+$schema_registrations
+} // namespace at

test/edge/test_operator_registration.cpp

@@ -23,6 +23,27 @@ TEST(OperatorRegistrationTest, Add) {
     expected = at::fill(expected, 2);
     ASSERT_TRUE(expected.equal(kernel_values[3]->toTensor()));
 
+}
+
+// custom::add_3.out(Tensor a, Tensor b, Tensor c, *, Tensor(a!) out) -> Tensor(a!)
+TEST(OperatorRegistrationTest, CustomAdd3) {
+    EValue values[4];
+    values[0] = EValue(at::ones({2, 3}));
+    values[1] = EValue(at::ones({2, 3}));
+    values[2] = EValue(at::ones({2, 3}));
+    values[3] = EValue(at::zeros({2, 3}));
+    ASSERT_TRUE(hasOpsFn("custom::add_3.out"));
+    auto op = getOpsFn("custom::add_3.out");
+
+    EValue* kernel_values[4];
+    for (size_t i = 0; i < 4; i++) {
+        kernel_values[i] = &values[i];
+    }
+    op(kernel_values);
+    at::Tensor expected = at::ones({2, 3});
+    expected = at::fill(expected, 3);
+    ASSERT_TRUE(expected.equal(kernel_values[3]->toTensor()));
+
 }
 } // namespace executor
 } // namespace torch

tools/test/test_executorch_custom_ops.py

@@ -40,7 +40,7 @@ class TestComputeNativeFunctionStub(expecttest.TestCase):
     def test_function_schema_generates_correct_kernel_tensor_out(self) -> None:
         obj = {"func": "custom::foo.out(Tensor self, *, Tensor(a!) out) -> Tensor(a!)"}
         expected = """
-at::Tensor & wrapper_out_foo_out(const at::Tensor & self, at::Tensor & out) {
+at::Tensor & wrapper_CPU_out_foo_out(const at::Tensor & self, at::Tensor & out) {
     return out;
 }
     """
@@ -49,7 +49,7 @@ at::Tensor & wrapper_out_foo_out(const at::Tensor & self, at::Tensor & out) {
     def test_function_schema_generates_correct_kernel_no_out(self) -> None:
         obj = {"func": "custom::foo.Tensor(Tensor self) -> Tensor"}
         expected = """
-at::Tensor wrapper_Tensor_foo(const at::Tensor & self) {
+at::Tensor wrapper_CPU_Tensor_foo(const at::Tensor & self) {
     return self;
 }
     """
@@ -58,7 +58,7 @@ at::Tensor wrapper_Tensor_foo(const at::Tensor & self) {
     def test_function_schema_generates_correct_kernel_no_return(self) -> None:
         obj = {"func": "custom::foo(Tensor self, *, Tensor(a!)[] out) -> ()"}
         expected = f"""
-void wrapper__foo_out(const at::Tensor & self, at::TensorList out) {{
+void wrapper_CPU__foo_out(const at::Tensor & self, at::TensorList out) {{
 {SPACES}
 }}
     """

torchgen/executorch/api/custom_ops.py

@@ -23,7 +23,7 @@ class ComputeNativeFunctionStub:
             return None
 
         sig = DispatcherSignature.from_schema(
-            f.func, prefix=f"wrapper_{f.func.name.overload_name}_", symint=False
+            f.func, prefix=f"wrapper_CPU_{f.func.name.overload_name}_", symint=False
         )
         assert sig is not None
         if len(f.func.returns) == 0:

torchgen/gen_executorch.py

@@ -46,7 +46,7 @@ from torchgen.utils import (
 
 
 def static_dispatch(
-    sig: ExecutorchCppSignature,
+    sig: Union[CppSignature, ExecutorchCppSignature],
     f: NativeFunction,
     backend_indices: List[BackendIndex],
 ) -> str:
@@ -99,12 +99,16 @@ class ComputeFunction:
             return None
         if Variant.function not in f.variants:
             return None
-
+        sig: Union[CppSignature, ExecutorchCppSignature] = (
-        if self.use_aten_lib:
+            CppSignatureGroup.from_native_function(
-            comma = ", "
-            sig = CppSignatureGroup.from_native_function(
                 f, method=False, fallback_binding=f.manual_cpp_binding
             ).most_faithful_signature()
+            if self.use_aten_lib
+            else ExecutorchCppSignature.from_native_function(f)
+        )
+        if self.use_aten_lib and f.namespace == "aten":
+            comma = ", "
+
             return f"""
 // {f.namespace}::{f.func}
 TORCH_API inline {sig.decl()} {{
@@ -114,7 +118,7 @@ TORCH_API inline {sig.decl()} {{
 
         else:
             return static_dispatch(
-                ExecutorchCppSignature.from_native_function(f),
+                sig,
                 f,
                 backend_indices=self.static_dispatch_backend_indices,
             )
@@ -280,9 +284,12 @@ def gen_headers(
     cpu_fm.write(
         "Functions.h",
         lambda: {
-            "static_dispatch_extra_headers": "#include <ATen/Functions.h>"
+            "static_dispatch_extra_headers": [
+                '#include "CustomOpsNativeFunctions.h"',
+                "#include <ATen/Functions.h>",
+            ]
             if use_aten_lib
-            else '#include "NativeFunctions.h"',
+            else ['#include "NativeFunctions.h"'],
             "Functions_declarations": gen_functions_declarations(
                 native_functions=native_functions,
                 static_dispatch_idx=static_dispatch_idx,
@@ -314,7 +321,6 @@ def gen_custom_ops(
     cpu_fm: FileManager,
     rocm: bool,
 ) -> None:
-
     dispatch_key = DispatchKey.CPU
     backend_index = backend_indices[dispatch_key]
     (
@@ -326,11 +332,22 @@ def gen_custom_ops(
         backend_index=backend_index,
         rocm=rocm,
     )
+    cpu_fm.write_with_template(
+        "CustomOpsNativeFunctions.h",
+        "NativeFunctions.h",
+        lambda: {
+            "nativeFunctions_declarations": get_native_function_declarations(
+                grouped_native_functions=native_functions,
+                backend_indices=backend_indices,
+                native_function_decl_gen=dest.compute_native_function_declaration,
+            ),
+        },
+    )
     cpu_fm.write_with_template(
         f"Register{dispatch_key}CustomOps.cpp",
         "RegisterDispatchKeyCustomOps.cpp",
         lambda: {
-            "ops_headers": '#include "NativeFunctions.h"',
+            "ops_headers": '#include "CustomOpsNativeFunctions.h"',
             "DispatchKey": dispatch_key,
             "dispatch_namespace": dispatch_key.lower(),
             "dispatch_namespaced_definitions": "",
@@ -482,35 +499,35 @@ def parse_yaml_files(
             native_yaml_path = os.path.join(tmpdirname, "functions.yaml")
             with open(native_yaml_path, "w"):
                 pass
-
+        # Translate native_yaml_path to the same format of native_functions.yaml
-        # If custom_ops_yaml_path exists, combine both files.
-        if custom_ops_yaml_path and os.path.exists(custom_ops_yaml_path):
-            combined_yaml_path = os.path.join(tmpdirname, "combined.yaml")
-            with open(combined_yaml_path, "w") as tmp:
-                with open(native_yaml_path, "r") as native:
-                    for line in native:
-                        tmp.write(line)
-                with open(custom_ops_yaml_path, "r") as custom:
-                    for line in custom:
-                        tmp.write(line)
-            custom_ops_parsed_yaml = parse_native_yaml(
-                custom_ops_yaml_path, tags_yaml_path, None, skip_native_fns_gen=True
-            )
-        else:
-            # No custom_ops; just parse native_yaml_path.
-            custom_ops_parsed_yaml = None
-            combined_yaml_path = native_yaml_path
         translated_yaml_path = os.path.join(tmpdirname, "translated.yaml")
         with open(translated_yaml_path, "w") as translated:
             translate_native_yaml(
                 tags_yaml_path,
                 aten_yaml_path,
-                combined_yaml_path,
+                native_yaml_path,
                 use_aten_lib,
                 translated,
             )
+        # If custom_ops_yaml_path doesn't exist, point to an empty file.
+        if not custom_ops_yaml_path or not os.path.exists(custom_ops_yaml_path):
+            custom_ops_yaml_path = os.path.join(tmpdirname, "custom_ops.yaml")
+            with open(custom_ops_yaml_path, "w"):
+                pass
+        combined_yaml_path = os.path.join(tmpdirname, "combined.yaml")
+        with open(combined_yaml_path, "w") as tmp, open(
+            translated_yaml_path, "r"
+        ) as native, open(custom_ops_yaml_path, "r") as custom:
+            for line in native.readlines():
+                tmp.write(line)
+            for line in custom.readlines():
+                tmp.write(line)
+        custom_ops_parsed_yaml = parse_native_yaml(
+            custom_ops_yaml_path, tags_yaml_path, None, skip_native_fns_gen=True
+        )
+
         parsed_yaml = parse_native_yaml(
-            translated_yaml_path,
+            combined_yaml_path,
             tags_yaml_path,
             None,
             skip_native_fns_gen=(not gen_native_fns),