Arm backend: Add running manifest to track public API (#18528)

Add a manifest file that tracks the state of the public API. This will
acts as a current snapshot of what the public API looks like. This
manifest file can then be used in future scripts and tests to make sure
that a commit does not break the API without proper deprecation.

For each release of Executorch there will be a static manifest file
generated from the "running" manifest. Those manifest files will be
immutable.

Signed-off-by: Sebastian Larsson <sebastian.larsson@arm.com>

Author: Sebastian-Larsson

backends/arm/__init__.py

@@ -0,0 +1,49 @@
+# Copyright 2026 Arm Limited and/or its affiliates.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+"""Public entry points for the Arm backend.
+
+Public API is defined by explicit module exports (e.g., ``.vgf``, ``.ethosu``,
+``.quantizer``). Selected symbols are re-exported here for convenience.
+
+"""
+
+from __future__ import annotations
+
+import importlib
+from typing import Any
+
+# Public for tooling (manifest generation and API validation).
+LAZY_IMPORTS = {
+    "EthosUBackend": ("executorch.backends.arm.ethosu", "EthosUBackend"),
+    "EthosUCompileSpec": ("executorch.backends.arm.ethosu", "EthosUCompileSpec"),
+    "EthosUPartitioner": ("executorch.backends.arm.ethosu", "EthosUPartitioner"),
+    "VgfBackend": ("executorch.backends.arm.vgf", "VgfBackend"),
+    "VgfCompileSpec": ("executorch.backends.arm.vgf", "VgfCompileSpec"),
+    "VgfPartitioner": ("executorch.backends.arm.vgf", "VgfPartitioner"),
+    "EthosUQuantizer": ("executorch.backends.arm.quantizer", "EthosUQuantizer"),
+    "VgfQuantizer": ("executorch.backends.arm.quantizer", "VgfQuantizer"),
+    ("get_symmetric_quantization_config"): (
+        "executorch.backends.arm.quantizer",
+        "get_symmetric_quantization_config",
+    ),
+    ("get_symmetric_a16w8_quantization_config"): (
+        "executorch.backends.arm.quantizer",
+        "get_symmetric_a16w8_quantization_config",
+    ),
+}
+
+
+def __getattr__(name: str) -> Any:
+    if name in LAZY_IMPORTS:
+        module_name, attr = LAZY_IMPORTS[name]
+        module = importlib.import_module(module_name)
+        value = getattr(module, attr)
+        globals()[name] = value
+        return value
+    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
+
+
+def __dir__() -> list[str]:
+    return sorted(list(globals()) + list(LAZY_IMPORTS))

backends/arm/public_api_manifests/api_manifest_running.toml

@@ -0,0 +1,177 @@
+# Copyright 2026 Arm Limited and/or its affiliates.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+#
+# This file is generated by
+# backends/arm/scripts/generate_public_api_manifest.py
+
+[python]
+
+[python.EthosUBackend]
+kind = "class"
+signature = "EthosUBackend()"
+
+[python.EthosUBackend.preprocess]
+kind = "function"
+signature = "EthosUBackend.preprocess(edge_program: torch.export.exported_program.ExportedProgram, compile_specs: List[executorch.exir.backend.compile_spec_schema.CompileSpec]) -> executorch.exir.backend.backend_details.PreprocessResult"
+
+[python.EthosUCompileSpec]
+kind = "class"
+signature = "EthosUCompileSpec(target: str, system_config: str | None = None, memory_mode: str | None = None, extra_flags: list[str] | None = None, config_ini: str | None = 'Arm/vela.ini')"
+
+[python.EthosUCompileSpec.DebugMode]
+kind = "enum"
+signature = "EthosUCompileSpec.DebugMode(value, names=None, *, module=None, qualname=None, type=None, start=1)"
+
+[python.EthosUCompileSpec.__eq__]
+kind = "function"
+signature = "EthosUCompileSpec.__eq__(self, other)"
+
+[python.EthosUCompileSpec.__repr__]
+kind = "function"
+signature = "EthosUCompileSpec.__repr__(self)"
+
+[python.EthosUCompileSpec.dump_debug_info]
+kind = "function"
+signature = "EthosUCompileSpec.dump_debug_info(self, debug_mode: executorch.backends.arm.common.arm_compile_spec.ArmCompileSpec.DebugMode | None)"
+
+[python.EthosUCompileSpec.dump_intermediate_artifacts_to]
+kind = "function"
+signature = "EthosUCompileSpec.dump_intermediate_artifacts_to(self, output_path: str | None)"
+
+[python.EthosUCompileSpec.set_pass_pipeline_config]
+kind = "function"
+signature = "EthosUCompileSpec.set_pass_pipeline_config(self, config: executorch.backends.arm.common.pipeline_config.ArmPassPipelineConfig) -> None"
+
+[python.EthosUPartitioner]
+kind = "class"
+signature = "EthosUPartitioner(compile_spec: executorch.backends.arm.ethosu.compile_spec.EthosUCompileSpec, additional_checks: Optional[Sequence[torch.fx.passes.operator_support.OperatorSupportBase]] = None) -> None"
+
+[python.EthosUPartitioner.ops_to_not_decompose]
+kind = "function"
+signature = "EthosUPartitioner.ops_to_not_decompose(self, ep: torch.export.exported_program.ExportedProgram) -> Tuple[List[torch._ops.OpOverload], Optional[Callable[[torch.fx.node.Node], bool]]]"
+
+[python.EthosUPartitioner.partition]
+kind = "function"
+signature = "EthosUPartitioner.partition(self, exported_program: torch.export.exported_program.ExportedProgram) -> executorch.exir.backend.partitioner.PartitionResult"
+
+[python.EthosUQuantizer]
+kind = "class"
+signature = "EthosUQuantizer(compile_spec: 'EthosUCompileSpec', use_composable_quantizer: 'bool' = False) -> 'None'"
+
+[python.EthosUQuantizer.annotate]
+kind = "function"
+signature = "EthosUQuantizer.annotate(self, model: 'GraphModule') -> 'GraphModule'"
+
+[python.EthosUQuantizer.set_global]
+kind = "function"
+signature = "EthosUQuantizer.set_global(self, quantization_config: 'Optional[QuantizationConfig]') -> 'TOSAQuantizer'"
+
+[python.EthosUQuantizer.set_io]
+kind = "function"
+signature = "EthosUQuantizer.set_io(self, quantization_config: 'Optional[QuantizationConfig]') -> 'TOSAQuantizer'"
+
+[python.EthosUQuantizer.set_module_name]
+kind = "function"
+signature = "EthosUQuantizer.set_module_name(self, module_name: 'str', quantization_config: 'Optional[QuantizationConfig]') -> 'TOSAQuantizer'"
+
+[python.EthosUQuantizer.set_module_type]
+kind = "function"
+signature = "EthosUQuantizer.set_module_type(self, module_type: 'Callable', quantization_config: 'Optional[QuantizationConfig]') -> 'TOSAQuantizer'"
+
+[python.EthosUQuantizer.transform_for_annotation]
+kind = "function"
+signature = "EthosUQuantizer.transform_for_annotation(self, model: 'GraphModule') -> 'GraphModule'"
+
+[python.EthosUQuantizer.validate]
+kind = "function"
+signature = "EthosUQuantizer.validate(self, model: 'GraphModule') -> 'None'"
+
+[python.VgfBackend]
+kind = "class"
+signature = "VgfBackend()"
+
+[python.VgfBackend.preprocess]
+kind = "function"
+signature = "VgfBackend.preprocess(edge_program: torch.export.exported_program.ExportedProgram, compile_specs: List[executorch.exir.backend.compile_spec_schema.CompileSpec]) -> executorch.exir.backend.backend_details.PreprocessResult"
+
+[python.VgfCompileSpec]
+kind = "class"
+signature = "VgfCompileSpec(tosa_spec: executorch.backends.arm.tosa.specification.TosaSpecification | str | None = None, compiler_flags: list[str] | None = None)"
+
+[python.VgfCompileSpec.DebugMode]
+kind = "enum"
+signature = "VgfCompileSpec.DebugMode(value, names=None, *, module=None, qualname=None, type=None, start=1)"
+
+[python.VgfCompileSpec.__eq__]
+kind = "function"
+signature = "VgfCompileSpec.__eq__(self, other)"
+
+[python.VgfCompileSpec.__repr__]
+kind = "function"
+signature = "VgfCompileSpec.__repr__(self)"
+
+[python.VgfCompileSpec.dump_debug_info]
+kind = "function"
+signature = "VgfCompileSpec.dump_debug_info(self, debug_mode: executorch.backends.arm.common.arm_compile_spec.ArmCompileSpec.DebugMode | None)"
+
+[python.VgfCompileSpec.dump_intermediate_artifacts_to]
+kind = "function"
+signature = "VgfCompileSpec.dump_intermediate_artifacts_to(self, output_path: str | None)"
+
+[python.VgfCompileSpec.set_pass_pipeline_config]
+kind = "function"
+signature = "VgfCompileSpec.set_pass_pipeline_config(self, config: executorch.backends.arm.common.pipeline_config.ArmPassPipelineConfig) -> None"
+
+[python.VgfPartitioner]
+kind = "class"
+signature = "VgfPartitioner(compile_spec: executorch.backends.arm.vgf.compile_spec.VgfCompileSpec, additional_checks: Optional[Sequence[torch.fx.passes.operator_support.OperatorSupportBase]] = None) -> None"
+
+[python.VgfPartitioner.ops_to_not_decompose]
+kind = "function"
+signature = "VgfPartitioner.ops_to_not_decompose(self, ep: torch.export.exported_program.ExportedProgram) -> Tuple[List[torch._ops.OpOverload], Optional[Callable[[torch.fx.node.Node], bool]]]"
+
+[python.VgfPartitioner.partition]
+kind = "function"
+signature = "VgfPartitioner.partition(self, exported_program: torch.export.exported_program.ExportedProgram) -> executorch.exir.backend.partitioner.PartitionResult"
+
+[python.VgfQuantizer]
+kind = "class"
+signature = "VgfQuantizer(compile_spec: 'VgfCompileSpec', use_composable_quantizer: 'bool' = False) -> 'None'"
+
+[python.VgfQuantizer.annotate]
+kind = "function"
+signature = "VgfQuantizer.annotate(self, model: 'GraphModule') -> 'GraphModule'"
+
+[python.VgfQuantizer.set_global]
+kind = "function"
+signature = "VgfQuantizer.set_global(self, quantization_config: 'Optional[QuantizationConfig]') -> 'TOSAQuantizer'"
+
+[python.VgfQuantizer.set_io]
+kind = "function"
+signature = "VgfQuantizer.set_io(self, quantization_config: 'Optional[QuantizationConfig]') -> 'TOSAQuantizer'"
+
+[python.VgfQuantizer.set_module_name]
+kind = "function"
+signature = "VgfQuantizer.set_module_name(self, module_name: 'str', quantization_config: 'Optional[QuantizationConfig]') -> 'TOSAQuantizer'"
+
+[python.VgfQuantizer.set_module_type]
+kind = "function"
+signature = "VgfQuantizer.set_module_type(self, module_type: 'Callable', quantization_config: 'Optional[QuantizationConfig]') -> 'TOSAQuantizer'"
+
+[python.VgfQuantizer.transform_for_annotation]
+kind = "function"
+signature = "VgfQuantizer.transform_for_annotation(self, model: 'GraphModule') -> 'GraphModule'"
+
+[python.VgfQuantizer.validate]
+kind = "function"
+signature = "VgfQuantizer.validate(self, model: 'GraphModule') -> 'None'"
+
+[python.get_symmetric_a16w8_quantization_config]
+kind = "function"
+signature = "get_symmetric_a16w8_quantization_config(is_per_channel: 'bool' = True, is_qat: 'bool' = False, is_dynamic: 'bool' = False, weight_qmin: 'int' = -127, weight_qmax: 'int' = 127, epsilon: 'float' = 0.000244140625) -> 'QuantizationConfig'"
+
+[python.get_symmetric_quantization_config]
+kind = "function"
+signature = "get_symmetric_quantization_config(is_per_channel: 'bool' = True, is_qat: 'bool' = False, is_dynamic: 'bool' = False, act_qmin: 'int' = -128, act_qmax: 'int' = 127, weight_qmin: 'int' = -127, weight_qmax: 'int' = 127, eps: 'float' = 1.52587890625e-05) -> 'QuantizationConfig'"

backends/arm/scripts/generate_public_api_manifest.py

@@ -0,0 +1,137 @@
+# Copyright 2026 Arm Limited and/or its affiliates.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+"""Generate the Arm backend public API manifest."""
+
+from __future__ import annotations
+
+import enum
+import inspect
+from datetime import datetime
+from pathlib import Path
+from typing import Any, cast
+
+import executorch.backends.arm as arm
+from executorch.backends.arm import LAZY_IMPORTS
+
+ARM_PREFIX = "executorch.backends.arm"
+COPYRIGHT_START_YEAR = 2026
+HEADER = """# Copyright {years} Arm Limited and/or its affiliates.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+#
+# This file is generated by
+# backends/arm/scripts/generate_public_api_manifest.py
+"""
+MANIFEST_PATH = (
+    Path(__file__).resolve().parents[1]
+    / "public_api_manifests"
+    / "api_manifest_running.toml"
+)
+
+
+def _copyright_year_range() -> str:
+    current_year = datetime.now().year
+    if current_year <= COPYRIGHT_START_YEAR:
+        return str(COPYRIGHT_START_YEAR)
+    return f"{COPYRIGHT_START_YEAR}-{current_year}"
+
+
+def _is_public(name: str) -> bool:
+    return not name.startswith("_") or (name.startswith("__") and name.endswith("__"))
+
+
+def _is_init(name: str) -> bool:
+    # Skip constructors so semantically equivalent classes with an implicit
+    # default __init__ do not produce different manifest entries.
+    return name != "__init__"
+
+
+def _is_backend(obj: object) -> bool:
+    return getattr(obj, "__module__", "").startswith(ARM_PREFIX)
+
+
+def _api_kind(obj: object) -> str:
+    if inspect.isclass(obj):
+        return "enum" if issubclass(obj, enum.Enum) else "class"
+    return "function"
+
+
+def _api_signature(path: str, obj: object) -> str:
+    try:
+        return f"{path}{inspect.signature(cast(Any, obj))}"
+    except (TypeError, ValueError):
+        return f"{path}()"
+
+
+def _owner(cls: type, name: str) -> type | None:
+    for base in cls.__mro__:
+        if name in vars(base):
+            return base
+    return None
+
+
+def _is_unstable_api(obj: object) -> bool:
+    return getattr(obj, "__deprecated__", None) is not None
+
+
+def _collect_entry(
+    path: str,
+    obj: object,
+    entries: dict[str, dict[str, str]],
+) -> None:
+    if _is_unstable_api(obj):
+        return
+    entries[path] = {"kind": _api_kind(obj), "signature": _api_signature(path, obj)}
+    if not inspect.isclass(obj):
+        return
+
+    for name in sorted(dir(obj)):
+        if not _is_public(name) or not _is_init(name):
+            continue
+        base = _owner(obj, name)
+        if base is None or not _is_backend(base):
+            continue
+        member = getattr(obj, name)
+        if inspect.isclass(member) or callable(member):
+            _collect_entry(f"{path}.{name}", member, entries)
+
+
+def _collect_public_api() -> dict[str, dict[str, str]]:
+    entries: dict[str, dict[str, str]] = {}
+    for name in sorted(LAZY_IMPORTS):
+        _collect_entry(name, getattr(arm, name), entries)
+    return entries
+
+
+def _render_manifest(entries: dict[str, dict[str, str]]) -> str:
+    lines = [HEADER.format(years=_copyright_year_range()).rstrip(), "", "[python]", ""]
+    for path in sorted(entries):
+        entry = entries[path]
+        lines.extend(
+            [
+                f"[python.{path}]",
+                f'kind = "{entry["kind"]}"',
+                f'signature = "{entry["signature"]}"',
+                "",
+            ]
+        )
+    return "\n".join(lines)
+
+
+def generate_manifest_from_init(
+    *,
+    repo_path: Path | None = None,
+) -> str:
+    del repo_path
+    return _render_manifest(_collect_public_api())
+
+
+def main() -> None:
+    MANIFEST_PATH.write_text(generate_manifest_from_init(), encoding="utf-8")
+
+
+if __name__ == "__main__":
+    main()