[Mlir-commits] [mlir] 6350bb3 - [mlir][py] Mark all type caster `from_{cpp, python}` methods as noexcept (#143866)
llvmlistbot at llvm.org
llvmlistbot at llvm.org
Tue Jul 15 07:58:14 PDT 2025
Author: Nicholas Junge
Date: 2025-07-15T10:58:10-04:00
New Revision: 6350bb3ed362ef5063ebd07d444d7dd4f5342541
URL: https://github.com/llvm/llvm-project/commit/6350bb3ed362ef5063ebd07d444d7dd4f5342541
DIFF: https://github.com/llvm/llvm-project/commit/6350bb3ed362ef5063ebd07d444d7dd4f5342541.diff
LOG: [mlir][py] Mark all type caster `from_{cpp,python}` methods as noexcept (#143866)
This is mentioned as a "must" in
https://nanobind.readthedocs.io/en/latest/porting.html#type-casters when
implementing type casters.
While most of the existing `from_cpp` methods were already marked
noexcept, many of the `from_python` methods were not. This commit adds
the missing noexcept declarations to all type casters found in
`NanobindAdaptors.h`.
---------
Co-authored-by: Maksim Levental <maksim.levental at gmail.com>
Added:
Modified:
mlir/include/mlir/Bindings/Python/NanobindAdaptors.h
mlir/test/python/dialects/python_test.py
mlir/test/python/lib/PythonTestModuleNanobind.cpp
Removed:
################################################################################
diff --git a/mlir/include/mlir/Bindings/Python/NanobindAdaptors.h b/mlir/include/mlir/Bindings/Python/NanobindAdaptors.h
index 2dd35c097c796..8dcf91e5806bd 100644
--- a/mlir/include/mlir/Bindings/Python/NanobindAdaptors.h
+++ b/mlir/include/mlir/Bindings/Python/NanobindAdaptors.h
@@ -20,6 +20,7 @@
#define MLIR_BINDINGS_PYTHON_NANOBINDADAPTORS_H
#include <cstdint>
+#include <optional>
#include "mlir-c/Diagnostics.h"
#include "mlir-c/IR.h"
@@ -43,18 +44,14 @@ namespace detail {
/// with a raw handle (unowned). The returned object's lifetime may not extend
/// beyond the apiObject handle without explicitly having its refcount increased
/// (i.e. on return).
-static nanobind::object mlirApiObjectToCapsule(nanobind::handle apiObject) {
+static std::optional<nanobind::object>
+mlirApiObjectToCapsule(nanobind::handle apiObject) {
if (PyCapsule_CheckExact(apiObject.ptr()))
return nanobind::borrow<nanobind::object>(apiObject);
nanobind::object api =
nanobind::getattr(apiObject, MLIR_PYTHON_CAPI_PTR_ATTR, nanobind::none());
- if (api.is_none()) {
- std::string repr = nanobind::cast<std::string>(nanobind::repr(apiObject));
- throw nanobind::type_error(
- (llvm::Twine("Expected an MLIR object (got ") + repr + ").")
- .str()
- .c_str());
- }
+ if (api.is_none())
+ return {};
return api;
}
@@ -67,12 +64,9 @@ static nanobind::object mlirApiObjectToCapsule(nanobind::handle apiObject) {
template <>
struct type_caster<MlirAffineMap> {
NB_TYPE_CASTER(MlirAffineMap, const_name("MlirAffineMap"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToAffineMap(capsule.ptr());
- if (mlirAffineMapIsNull(value)) {
- return false;
- }
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToAffineMap(capsule->ptr());
return !mlirAffineMapIsNull(value);
}
static handle from_cpp(MlirAffineMap v, rv_policy,
@@ -90,9 +84,9 @@ struct type_caster<MlirAffineMap> {
template <>
struct type_caster<MlirAttribute> {
NB_TYPE_CASTER(MlirAttribute, const_name("MlirAttribute"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToAttribute(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToAttribute(capsule->ptr());
return !mlirAttributeIsNull(value);
}
static handle from_cpp(MlirAttribute v, rv_policy,
@@ -111,9 +105,9 @@ struct type_caster<MlirAttribute> {
template <>
struct type_caster<MlirBlock> {
NB_TYPE_CASTER(MlirBlock, const_name("MlirBlock"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToBlock(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToBlock(capsule->ptr());
return !mlirBlockIsNull(value);
}
};
@@ -122,7 +116,7 @@ struct type_caster<MlirBlock> {
template <>
struct type_caster<MlirContext> {
NB_TYPE_CASTER(MlirContext, const_name("MlirContext"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
if (src.is_none()) {
// Gets the current thread-bound context.
// TODO: This raises an error of "No current context" currently.
@@ -132,8 +126,8 @@ struct type_caster<MlirContext> {
.attr("Context")
.attr("current");
}
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToContext(capsule.ptr());
+ std::optional<nanobind::object> capsule = mlirApiObjectToCapsule(src);
+ value = mlirPythonCapsuleToContext(capsule->ptr());
return !mlirContextIsNull(value);
}
};
@@ -142,9 +136,9 @@ struct type_caster<MlirContext> {
template <>
struct type_caster<MlirDialectRegistry> {
NB_TYPE_CASTER(MlirDialectRegistry, const_name("MlirDialectRegistry"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToDialectRegistry(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToDialectRegistry(capsule->ptr());
return !mlirDialectRegistryIsNull(value);
}
static handle from_cpp(MlirDialectRegistry v, rv_policy,
@@ -162,15 +156,15 @@ struct type_caster<MlirDialectRegistry> {
template <>
struct type_caster<MlirLocation> {
NB_TYPE_CASTER(MlirLocation, const_name("MlirLocation"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
if (src.is_none()) {
// Gets the current thread-bound context.
src = nanobind::module_::import_(MAKE_MLIR_PYTHON_QUALNAME("ir"))
.attr("Location")
.attr("current");
}
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToLocation(capsule.ptr());
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToLocation(capsule->ptr());
return !mlirLocationIsNull(value);
}
static handle from_cpp(MlirLocation v, rv_policy,
@@ -188,9 +182,9 @@ struct type_caster<MlirLocation> {
template <>
struct type_caster<MlirModule> {
NB_TYPE_CASTER(MlirModule, const_name("MlirModule"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToModule(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToModule(capsule->ptr());
return !mlirModuleIsNull(value);
}
static handle from_cpp(MlirModule v, rv_policy,
@@ -209,12 +203,13 @@ template <>
struct type_caster<MlirFrozenRewritePatternSet> {
NB_TYPE_CASTER(MlirFrozenRewritePatternSet,
const_name("MlirFrozenRewritePatternSet"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToFrozenRewritePatternSet(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToFrozenRewritePatternSet(capsule->ptr());
return value.ptr != nullptr;
}
- static handle from_cpp(MlirFrozenRewritePatternSet v, rv_policy, handle) {
+ static handle from_cpp(MlirFrozenRewritePatternSet v, rv_policy,
+ handle) noexcept {
nanobind::object capsule = nanobind::steal<nanobind::object>(
mlirPythonFrozenRewritePatternSetToCapsule(v));
return nanobind::module_::import_(MAKE_MLIR_PYTHON_QUALNAME("rewrite"))
@@ -228,9 +223,9 @@ struct type_caster<MlirFrozenRewritePatternSet> {
template <>
struct type_caster<MlirOperation> {
NB_TYPE_CASTER(MlirOperation, const_name("MlirOperation"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToOperation(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToOperation(capsule->ptr());
return !mlirOperationIsNull(value);
}
static handle from_cpp(MlirOperation v, rv_policy,
@@ -250,9 +245,9 @@ struct type_caster<MlirOperation> {
template <>
struct type_caster<MlirValue> {
NB_TYPE_CASTER(MlirValue, const_name("MlirValue"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToValue(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToValue(capsule->ptr());
return !mlirValueIsNull(value);
}
static handle from_cpp(MlirValue v, rv_policy,
@@ -273,9 +268,9 @@ struct type_caster<MlirValue> {
template <>
struct type_caster<MlirPassManager> {
NB_TYPE_CASTER(MlirPassManager, const_name("MlirPassManager"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToPassManager(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToPassManager(capsule->ptr());
return !mlirPassManagerIsNull(value);
}
};
@@ -284,9 +279,9 @@ struct type_caster<MlirPassManager> {
template <>
struct type_caster<MlirTypeID> {
NB_TYPE_CASTER(MlirTypeID, const_name("MlirTypeID"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToTypeID(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToTypeID(capsule->ptr());
return !mlirTypeIDIsNull(value);
}
static handle from_cpp(MlirTypeID v, rv_policy,
@@ -306,9 +301,9 @@ struct type_caster<MlirTypeID> {
template <>
struct type_caster<MlirType> {
NB_TYPE_CASTER(MlirType, const_name("MlirType"))
- bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) {
- nanobind::object capsule = mlirApiObjectToCapsule(src);
- value = mlirPythonCapsuleToType(capsule.ptr());
+ bool from_python(handle src, uint8_t flags, cleanup_list *cleanup) noexcept {
+ if (auto capsule = mlirApiObjectToCapsule(src))
+ value = mlirPythonCapsuleToType(capsule->ptr());
return !mlirTypeIsNull(value);
}
static handle from_cpp(MlirType t, rv_policy,
@@ -462,9 +457,10 @@ class mlir_attribute_subclass : public pure_subclass {
nanobind::object newCf = nanobind::cpp_function(
[superCls, isaFunction, captureTypeName](
nanobind::object cls, nanobind::object otherAttribute) {
- MlirAttribute rawAttribute =
- nanobind::cast<MlirAttribute>(otherAttribute);
- if (!isaFunction(rawAttribute)) {
+ MlirAttribute rawAttribute;
+ if (!nanobind::try_cast<MlirAttribute>(otherAttribute,
+ rawAttribute) ||
+ !isaFunction(rawAttribute)) {
auto origRepr =
nanobind::cast<std::string>(nanobind::repr(otherAttribute));
throw std::invalid_argument(
@@ -543,8 +539,9 @@ class mlir_type_subclass : public pure_subclass {
nanobind::object newCf = nanobind::cpp_function(
[superCls, isaFunction, captureTypeName](nanobind::object cls,
nanobind::object otherType) {
- MlirType rawType = nanobind::cast<MlirType>(otherType);
- if (!isaFunction(rawType)) {
+ MlirType rawType;
+ if (!nanobind::try_cast<MlirType>(otherType, rawType) ||
+ !isaFunction(rawType)) {
auto origRepr =
nanobind::cast<std::string>(nanobind::repr(otherType));
throw std::invalid_argument((llvm::Twine("Cannot cast type to ") +
@@ -625,8 +622,9 @@ class mlir_value_subclass : public pure_subclass {
nanobind::object newCf = nanobind::cpp_function(
[superCls, isaFunction, captureValueName](nanobind::object cls,
nanobind::object otherValue) {
- MlirValue rawValue = nanobind::cast<MlirValue>(otherValue);
- if (!isaFunction(rawValue)) {
+ MlirValue rawValue;
+ if (!nanobind::try_cast<MlirValue>(otherValue, rawValue) ||
+ !isaFunction(rawValue)) {
auto origRepr =
nanobind::cast<std::string>(nanobind::repr(otherValue));
throw std::invalid_argument((llvm::Twine("Cannot cast value to ") +
diff --git a/mlir/test/python/dialects/python_test.py b/mlir/test/python/dialects/python_test.py
index fd678f8321fd9..694616696a9e2 100644
--- a/mlir/test/python/dialects/python_test.py
+++ b/mlir/test/python/dialects/python_test.py
@@ -361,7 +361,9 @@ def testCustomAttribute():
try:
TestAttr(42)
except TypeError as e:
- assert "Expected an MLIR object" in str(e)
+ assert "Expected an MLIR object (got 42)" in str(e)
+ except ValueError as e:
+ assert "Cannot cast attribute to TestAttr (from 42)" in str(e)
else:
raise
@@ -406,7 +408,9 @@ def testCustomType():
try:
TestType(42)
except TypeError as e:
- assert "Expected an MLIR object" in str(e)
+ assert "Expected an MLIR object (got 42)" in str(e)
+ except ValueError as e:
+ assert "Cannot cast type to TestType (from 42)" in str(e)
else:
raise
diff --git a/mlir/test/python/lib/PythonTestModuleNanobind.cpp b/mlir/test/python/lib/PythonTestModuleNanobind.cpp
index dd0a9f2b66ea6..108df8da86a7e 100644
--- a/mlir/test/python/lib/PythonTestModuleNanobind.cpp
+++ b/mlir/test/python/lib/PythonTestModuleNanobind.cpp
@@ -113,8 +113,10 @@ NB_MODULE(_mlirPythonTestNanobind, m) {
.attr(MLIR_PYTHON_CAPI_VALUE_CASTER_REGISTER_ATTR)(
mlirRankedTensorTypeID)(
nanobind::cpp_function([valueCls](const nb::object &valueObj) {
- nb::object capsule = mlirApiObjectToCapsule(valueObj);
- MlirValue v = mlirPythonCapsuleToValue(capsule.ptr());
+ std::optional<nb::object> capsule =
+ mlirApiObjectToCapsule(valueObj);
+ assert(capsule.has_value() && "capsule is not null");
+ MlirValue v = mlirPythonCapsuleToValue(capsule.value().ptr());
MlirType t = mlirValueGetType(v);
// This is hyper-specific in order to exercise/test registering a
// value caster from cpp (but only for a single test case; see
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