pyo3_macros_backend/
pymethod.rs

1use std::borrow::Cow;
2use std::ffi::CString;
3
4use crate::attributes::{FromPyWithAttribute, NameAttribute, RenamingRule};
5use crate::method::{CallingConvention, ExtractErrorMode, PyArg};
6use crate::params::{impl_regular_arg_param, Holders};
7use crate::pyfunction::WarningFactory;
8use crate::utils::{Ctx, LitCStr};
9use crate::utils::{PythonDoc, TypeExt as _};
10use crate::{
11    method::{FnArg, FnSpec, FnType, SelfType},
12    pyfunction::PyFunctionOptions,
13};
14use crate::{quotes, utils};
15use proc_macro2::{Span, TokenStream};
16use quote::{format_ident, quote, quote_spanned, ToTokens};
17use syn::{ext::IdentExt, spanned::Spanned, Result};
18
19/// Generated code for a single pymethod item.
20pub struct MethodAndMethodDef {
21    /// The implementation of the Python wrapper for the pymethod
22    pub associated_method: TokenStream,
23    /// The method def which will be used to register this pymethod
24    pub method_def: TokenStream,
25}
26
27/// Generated code for a single pymethod item which is registered by a slot.
28pub struct MethodAndSlotDef {
29    /// The implementation of the Python wrapper for the pymethod
30    pub associated_method: TokenStream,
31    /// The slot def which will be used to register this pymethod
32    pub slot_def: TokenStream,
33}
34
35pub enum GeneratedPyMethod {
36    Method(MethodAndMethodDef),
37    Proto(MethodAndSlotDef),
38    SlotTraitImpl(String, TokenStream),
39}
40
41pub struct PyMethod<'a> {
42    kind: PyMethodKind,
43    method_name: String,
44    pub spec: FnSpec<'a>,
45}
46
47enum PyMethodKind {
48    Fn,
49    Proto(PyMethodProtoKind),
50}
51
52impl PyMethodKind {
53    fn from_name(name: &str) -> Self {
54        match name {
55            // Protocol implemented through slots
56            "__str__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__STR__)),
57            "__repr__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__REPR__)),
58            "__hash__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__HASH__)),
59            "__richcmp__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__RICHCMP__)),
60            "__get__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__GET__)),
61            "__iter__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__ITER__)),
62            "__next__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__NEXT__)),
63            "__await__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__AWAIT__)),
64            "__aiter__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__AITER__)),
65            "__anext__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__ANEXT__)),
66            "__len__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__LEN__)),
67            "__contains__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__CONTAINS__)),
68            "__concat__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__CONCAT__)),
69            "__repeat__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__REPEAT__)),
70            "__inplace_concat__" => {
71                PyMethodKind::Proto(PyMethodProtoKind::Slot(&__INPLACE_CONCAT__))
72            }
73            "__inplace_repeat__" => {
74                PyMethodKind::Proto(PyMethodProtoKind::Slot(&__INPLACE_REPEAT__))
75            }
76            "__getitem__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__GETITEM__)),
77            "__pos__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__POS__)),
78            "__neg__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__NEG__)),
79            "__abs__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__ABS__)),
80            "__invert__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__INVERT__)),
81            "__index__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__INDEX__)),
82            "__int__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__INT__)),
83            "__float__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__FLOAT__)),
84            "__bool__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__BOOL__)),
85            "__iadd__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IADD__)),
86            "__isub__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__ISUB__)),
87            "__imul__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IMUL__)),
88            "__imatmul__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IMATMUL__)),
89            "__itruediv__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__ITRUEDIV__)),
90            "__ifloordiv__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IFLOORDIV__)),
91            "__imod__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IMOD__)),
92            "__ipow__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IPOW__)),
93            "__ilshift__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__ILSHIFT__)),
94            "__irshift__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IRSHIFT__)),
95            "__iand__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IAND__)),
96            "__ixor__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IXOR__)),
97            "__ior__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__IOR__)),
98            "__getbuffer__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__GETBUFFER__)),
99            "__releasebuffer__" => PyMethodKind::Proto(PyMethodProtoKind::Slot(&__RELEASEBUFFER__)),
100            // Protocols implemented through traits
101            "__getattribute__" => {
102                PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__GETATTRIBUTE__))
103            }
104            "__getattr__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__GETATTR__)),
105            "__setattr__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__SETATTR__)),
106            "__delattr__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__DELATTR__)),
107            "__set__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__SET__)),
108            "__delete__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__DELETE__)),
109            "__setitem__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__SETITEM__)),
110            "__delitem__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__DELITEM__)),
111            "__add__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__ADD__)),
112            "__radd__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RADD__)),
113            "__sub__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__SUB__)),
114            "__rsub__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RSUB__)),
115            "__mul__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__MUL__)),
116            "__rmul__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RMUL__)),
117            "__matmul__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__MATMUL__)),
118            "__rmatmul__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RMATMUL__)),
119            "__floordiv__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__FLOORDIV__)),
120            "__rfloordiv__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RFLOORDIV__)),
121            "__truediv__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__TRUEDIV__)),
122            "__rtruediv__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RTRUEDIV__)),
123            "__divmod__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__DIVMOD__)),
124            "__rdivmod__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RDIVMOD__)),
125            "__mod__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__MOD__)),
126            "__rmod__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RMOD__)),
127            "__lshift__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__LSHIFT__)),
128            "__rlshift__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RLSHIFT__)),
129            "__rshift__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RSHIFT__)),
130            "__rrshift__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RRSHIFT__)),
131            "__and__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__AND__)),
132            "__rand__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RAND__)),
133            "__xor__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__XOR__)),
134            "__rxor__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RXOR__)),
135            "__or__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__OR__)),
136            "__ror__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__ROR__)),
137            "__pow__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__POW__)),
138            "__rpow__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__RPOW__)),
139            "__lt__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__LT__)),
140            "__le__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__LE__)),
141            "__eq__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__EQ__)),
142            "__ne__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__NE__)),
143            "__gt__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__GT__)),
144            "__ge__" => PyMethodKind::Proto(PyMethodProtoKind::SlotFragment(&__GE__)),
145            // Some tricky protocols which don't fit the pattern of the rest
146            "__call__" => PyMethodKind::Proto(PyMethodProtoKind::Call),
147            "__traverse__" => PyMethodKind::Proto(PyMethodProtoKind::Traverse),
148            "__clear__" => PyMethodKind::Proto(PyMethodProtoKind::Clear),
149            // Not a proto
150            _ => PyMethodKind::Fn,
151        }
152    }
153}
154
155enum PyMethodProtoKind {
156    Slot(&'static SlotDef),
157    Call,
158    Traverse,
159    Clear,
160    SlotFragment(&'static SlotFragmentDef),
161}
162
163impl<'a> PyMethod<'a> {
164    pub fn parse(
165        sig: &'a mut syn::Signature,
166        meth_attrs: &mut Vec<syn::Attribute>,
167        options: PyFunctionOptions,
168    ) -> Result<Self> {
169        check_generic(sig)?;
170        ensure_function_options_valid(&options)?;
171        let spec = FnSpec::parse(sig, meth_attrs, options)?;
172
173        let method_name = spec.python_name.to_string();
174        let kind = PyMethodKind::from_name(&method_name);
175
176        Ok(Self {
177            kind,
178            method_name,
179            spec,
180        })
181    }
182}
183
184pub fn is_proto_method(name: &str) -> bool {
185    match PyMethodKind::from_name(name) {
186        PyMethodKind::Fn => false,
187        PyMethodKind::Proto(_) => true,
188    }
189}
190
191pub fn gen_py_method(
192    cls: &syn::Type,
193    method: PyMethod<'_>,
194    meth_attrs: &[syn::Attribute],
195    ctx: &Ctx,
196) -> Result<GeneratedPyMethod> {
197    let spec = &method.spec;
198    let Ctx { pyo3_path, .. } = ctx;
199
200    if spec.asyncness.is_some() {
201        ensure_spanned!(
202            cfg!(feature = "experimental-async"),
203            spec.asyncness.span() => "async functions are only supported with the `experimental-async` feature"
204        );
205    }
206
207    Ok(match (method.kind, &spec.tp) {
208        // Class attributes go before protos so that class attributes can be used to set proto
209        // method to None.
210        (_, FnType::ClassAttribute) => {
211            GeneratedPyMethod::Method(impl_py_class_attribute(cls, spec, ctx)?)
212        }
213        (PyMethodKind::Proto(proto_kind), _) => {
214            ensure_no_forbidden_protocol_attributes(&proto_kind, spec, &method.method_name)?;
215            match proto_kind {
216                PyMethodProtoKind::Slot(slot_def) => {
217                    let slot = slot_def.generate_type_slot(cls, spec, &method.method_name, ctx)?;
218                    GeneratedPyMethod::Proto(slot)
219                }
220                PyMethodProtoKind::Call => {
221                    GeneratedPyMethod::Proto(impl_call_slot(cls, method.spec, ctx)?)
222                }
223                PyMethodProtoKind::Traverse => {
224                    GeneratedPyMethod::Proto(impl_traverse_slot(cls, spec, ctx)?)
225                }
226                PyMethodProtoKind::Clear => {
227                    GeneratedPyMethod::Proto(impl_clear_slot(cls, spec, ctx)?)
228                }
229                PyMethodProtoKind::SlotFragment(slot_fragment_def) => {
230                    let proto = slot_fragment_def.generate_pyproto_fragment(cls, spec, ctx)?;
231                    GeneratedPyMethod::SlotTraitImpl(method.method_name, proto)
232                }
233            }
234        }
235        // ordinary functions (with some specialties)
236        (_, FnType::Fn(_)) => GeneratedPyMethod::Method(impl_py_method_def(
237            cls,
238            spec,
239            &spec.get_doc(meth_attrs, ctx),
240            None,
241            ctx,
242        )?),
243        (_, FnType::FnClass(_)) => GeneratedPyMethod::Method(impl_py_method_def(
244            cls,
245            spec,
246            &spec.get_doc(meth_attrs, ctx),
247            Some(quote!(#pyo3_path::ffi::METH_CLASS)),
248            ctx,
249        )?),
250        (_, FnType::FnStatic) => GeneratedPyMethod::Method(impl_py_method_def(
251            cls,
252            spec,
253            &spec.get_doc(meth_attrs, ctx),
254            Some(quote!(#pyo3_path::ffi::METH_STATIC)),
255            ctx,
256        )?),
257        // special prototypes
258        (_, FnType::FnNew) | (_, FnType::FnNewClass(_)) => {
259            GeneratedPyMethod::Proto(impl_py_method_def_new(cls, spec, ctx)?)
260        }
261
262        (_, FnType::Getter(self_type)) => GeneratedPyMethod::Method(impl_py_getter_def(
263            cls,
264            PropertyType::Function {
265                self_type,
266                spec,
267                doc: spec.get_doc(meth_attrs, ctx),
268            },
269            ctx,
270        )?),
271        (_, FnType::Setter(self_type)) => GeneratedPyMethod::Method(impl_py_setter_def(
272            cls,
273            PropertyType::Function {
274                self_type,
275                spec,
276                doc: spec.get_doc(meth_attrs, ctx),
277            },
278            ctx,
279        )?),
280        (_, FnType::FnModule(_)) => {
281            unreachable!("methods cannot be FnModule")
282        }
283    })
284}
285
286pub fn check_generic(sig: &syn::Signature) -> syn::Result<()> {
287    let err_msg = |typ| format!("Python functions cannot have generic {typ} parameters");
288    for param in &sig.generics.params {
289        match param {
290            syn::GenericParam::Lifetime(_) => {}
291            syn::GenericParam::Type(_) => bail_spanned!(param.span() => err_msg("type")),
292            syn::GenericParam::Const(_) => bail_spanned!(param.span() => err_msg("const")),
293        }
294    }
295    Ok(())
296}
297
298fn ensure_function_options_valid(options: &PyFunctionOptions) -> syn::Result<()> {
299    if let Some(pass_module) = &options.pass_module {
300        bail_spanned!(pass_module.span() => "`pass_module` cannot be used on Python methods");
301    }
302    Ok(())
303}
304
305fn ensure_no_forbidden_protocol_attributes(
306    proto_kind: &PyMethodProtoKind,
307    spec: &FnSpec<'_>,
308    method_name: &str,
309) -> syn::Result<()> {
310    if let Some(signature) = &spec.signature.attribute {
311        // __call__ is allowed to have a signature, but nothing else is.
312        if !matches!(proto_kind, PyMethodProtoKind::Call) {
313            bail_spanned!(signature.kw.span() => format!("`signature` cannot be used with magic method `{}`", method_name));
314        }
315    }
316    if let Some(text_signature) = &spec.text_signature {
317        bail_spanned!(text_signature.kw.span() => format!("`text_signature` cannot be used with magic method `{}`", method_name));
318    }
319    Ok(())
320}
321
322/// Also used by pyfunction.
323pub fn impl_py_method_def(
324    cls: &syn::Type,
325    spec: &FnSpec<'_>,
326    doc: &PythonDoc,
327    flags: Option<TokenStream>,
328    ctx: &Ctx,
329) -> Result<MethodAndMethodDef> {
330    let Ctx { pyo3_path, .. } = ctx;
331    let wrapper_ident = format_ident!("__pymethod_{}__", spec.python_name);
332    let associated_method = spec.get_wrapper_function(&wrapper_ident, Some(cls), ctx)?;
333    let add_flags = flags.map(|flags| quote!(.flags(#flags)));
334    let methoddef_type = match spec.tp {
335        FnType::FnStatic => quote!(Static),
336        FnType::FnClass(_) => quote!(Class),
337        _ => quote!(Method),
338    };
339    let methoddef = spec.get_methoddef(quote! { #cls::#wrapper_ident }, doc, ctx);
340    let method_def = quote! {
341        #pyo3_path::impl_::pyclass::MaybeRuntimePyMethodDef::Static(
342            #pyo3_path::impl_::pymethods::PyMethodDefType::#methoddef_type(#methoddef #add_flags)
343        )
344    };
345    Ok(MethodAndMethodDef {
346        associated_method,
347        method_def,
348    })
349}
350
351/// Also used by pyclass.
352pub fn impl_py_method_def_new(
353    cls: &syn::Type,
354    spec: &FnSpec<'_>,
355    ctx: &Ctx,
356) -> Result<MethodAndSlotDef> {
357    let Ctx { pyo3_path, .. } = ctx;
358    let wrapper_ident = syn::Ident::new("__pymethod___new____", Span::call_site());
359    let associated_method = spec.get_wrapper_function(&wrapper_ident, Some(cls), ctx)?;
360    // Use just the text_signature_call_signature() because the class' Python name
361    // isn't known to `#[pymethods]` - that has to be attached at runtime from the PyClassImpl
362    // trait implementation created by `#[pyclass]`.
363    let text_signature_body = spec.text_signature_call_signature().map_or_else(
364        || quote!(::std::option::Option::None),
365        |text_signature| quote!(::std::option::Option::Some(#text_signature)),
366    );
367    let slot_def = quote! {
368        #pyo3_path::ffi::PyType_Slot {
369            slot: #pyo3_path::ffi::Py_tp_new,
370            pfunc: {
371                unsafe extern "C" fn trampoline(
372                    subtype: *mut #pyo3_path::ffi::PyTypeObject,
373                    args: *mut #pyo3_path::ffi::PyObject,
374                    kwargs: *mut #pyo3_path::ffi::PyObject,
375                ) -> *mut #pyo3_path::ffi::PyObject {
376                    #[allow(unknown_lints, non_local_definitions)]
377                    impl #pyo3_path::impl_::pyclass::PyClassNewTextSignature<#cls> for #pyo3_path::impl_::pyclass::PyClassImplCollector<#cls> {
378                        #[inline]
379                        fn new_text_signature(self) -> ::std::option::Option<&'static str> {
380                            #text_signature_body
381                        }
382                    }
383
384                    #pyo3_path::impl_::trampoline::newfunc(
385                        subtype,
386                        args,
387                        kwargs,
388                        #cls::#wrapper_ident
389                    )
390                }
391                trampoline
392            } as #pyo3_path::ffi::newfunc as _
393        }
394    };
395    Ok(MethodAndSlotDef {
396        associated_method,
397        slot_def,
398    })
399}
400
401fn impl_call_slot(cls: &syn::Type, mut spec: FnSpec<'_>, ctx: &Ctx) -> Result<MethodAndSlotDef> {
402    let Ctx { pyo3_path, .. } = ctx;
403
404    // HACK: __call__ proto slot must always use varargs calling convention, so change the spec.
405    // Probably indicates there's a refactoring opportunity somewhere.
406    spec.convention = CallingConvention::Varargs;
407
408    let wrapper_ident = syn::Ident::new("__pymethod___call____", Span::call_site());
409    let associated_method = spec.get_wrapper_function(&wrapper_ident, Some(cls), ctx)?;
410    let slot_def = quote! {
411        #pyo3_path::ffi::PyType_Slot {
412            slot: #pyo3_path::ffi::Py_tp_call,
413            pfunc: {
414                unsafe extern "C" fn trampoline(
415                    slf: *mut #pyo3_path::ffi::PyObject,
416                    args: *mut #pyo3_path::ffi::PyObject,
417                    kwargs: *mut #pyo3_path::ffi::PyObject,
418                ) -> *mut #pyo3_path::ffi::PyObject
419                {
420                    #pyo3_path::impl_::trampoline::ternaryfunc(
421                        slf,
422                        args,
423                        kwargs,
424                        #cls::#wrapper_ident
425                    )
426                }
427                trampoline
428            } as #pyo3_path::ffi::ternaryfunc as _
429        }
430    };
431    Ok(MethodAndSlotDef {
432        associated_method,
433        slot_def,
434    })
435}
436
437fn impl_traverse_slot(
438    cls: &syn::Type,
439    spec: &FnSpec<'_>,
440    ctx: &Ctx,
441) -> syn::Result<MethodAndSlotDef> {
442    let Ctx { pyo3_path, .. } = ctx;
443    if let (Some(py_arg), _) = split_off_python_arg(&spec.signature.arguments) {
444        return Err(syn::Error::new_spanned(py_arg.ty, "__traverse__ may not take `Python`. \
445            Usually, an implementation of `__traverse__(&self, visit: PyVisit<'_>) -> Result<(), PyTraverseError>` \
446            should do nothing but calls to `visit.call`. Most importantly, safe access to the GIL is prohibited \
447            inside implementations of `__traverse__`, i.e. `Python::attach` will panic."));
448    }
449
450    // check that the receiver does not try to smuggle an (implicit) `Python` token into here
451    if let FnType::Fn(SelfType::TryFromBoundRef(span))
452    | FnType::Fn(SelfType::Receiver {
453        mutable: true,
454        span,
455    }) = spec.tp
456    {
457        bail_spanned! { span =>
458            "__traverse__ may not take a receiver other than `&self`. Usually, an implementation of \
459            `__traverse__(&self, visit: PyVisit<'_>) -> Result<(), PyTraverseError>` \
460            should do nothing but calls to `visit.call`. Most importantly, safe access to the GIL is prohibited \
461            inside implementations of `__traverse__`, i.e. `Python::attach` will panic."
462        }
463    }
464
465    ensure_spanned!(
466        spec.warnings.is_empty(),
467        spec.warnings.span() => "__traverse__ cannot be used with #[pyo3(warn)]"
468    );
469
470    let rust_fn_ident = spec.name;
471
472    let associated_method = quote! {
473        pub unsafe extern "C" fn __pymethod_traverse__(
474            slf: *mut #pyo3_path::ffi::PyObject,
475            visit: #pyo3_path::ffi::visitproc,
476            arg: *mut ::std::os::raw::c_void,
477        ) -> ::std::os::raw::c_int {
478            #pyo3_path::impl_::pymethods::_call_traverse::<#cls>(slf, #cls::#rust_fn_ident, visit, arg, #cls::__pymethod_traverse__)
479        }
480    };
481    let slot_def = quote! {
482        #pyo3_path::ffi::PyType_Slot {
483            slot: #pyo3_path::ffi::Py_tp_traverse,
484            pfunc: #cls::__pymethod_traverse__ as #pyo3_path::ffi::traverseproc as _
485        }
486    };
487    Ok(MethodAndSlotDef {
488        associated_method,
489        slot_def,
490    })
491}
492
493fn impl_clear_slot(cls: &syn::Type, spec: &FnSpec<'_>, ctx: &Ctx) -> syn::Result<MethodAndSlotDef> {
494    let Ctx { pyo3_path, .. } = ctx;
495    let (py_arg, args) = split_off_python_arg(&spec.signature.arguments);
496    let self_type = match &spec.tp {
497        FnType::Fn(self_type) => self_type,
498        _ => bail_spanned!(spec.name.span() => "expected instance method for `__clear__` function"),
499    };
500    let mut holders = Holders::new();
501    let slf = self_type.receiver(cls, ExtractErrorMode::Raise, &mut holders, ctx);
502
503    if let [arg, ..] = args {
504        bail_spanned!(arg.ty().span() => "`__clear__` function expected to have no arguments");
505    }
506
507    let name = &spec.name;
508    let holders = holders.init_holders(ctx);
509    let fncall = if py_arg.is_some() {
510        quote!(#cls::#name(#slf, py))
511    } else {
512        quote!(#cls::#name(#slf))
513    };
514
515    let associated_method = quote! {
516        pub unsafe extern "C" fn __pymethod___clear____(
517            _slf: *mut #pyo3_path::ffi::PyObject,
518        ) -> ::std::os::raw::c_int {
519            #pyo3_path::impl_::pymethods::_call_clear(_slf, |py, _slf| {
520                #holders
521                let result = #fncall;
522                let result = #pyo3_path::impl_::wrap::converter(&result).wrap(result)?;
523                ::std::result::Result::Ok(result)
524            }, #cls::__pymethod___clear____)
525        }
526    };
527    let slot_def = quote! {
528        #pyo3_path::ffi::PyType_Slot {
529            slot: #pyo3_path::ffi::Py_tp_clear,
530            pfunc: #cls::__pymethod___clear____ as #pyo3_path::ffi::inquiry as _
531        }
532    };
533    Ok(MethodAndSlotDef {
534        associated_method,
535        slot_def,
536    })
537}
538
539pub(crate) fn impl_py_class_attribute(
540    cls: &syn::Type,
541    spec: &FnSpec<'_>,
542    ctx: &Ctx,
543) -> syn::Result<MethodAndMethodDef> {
544    let Ctx { pyo3_path, .. } = ctx;
545    let (py_arg, args) = split_off_python_arg(&spec.signature.arguments);
546    ensure_spanned!(
547        args.is_empty(),
548        args[0].ty().span() => "#[classattr] can only have one argument (of type pyo3::Python)"
549    );
550
551    ensure_spanned!(
552        spec.warnings.is_empty(),
553        spec.warnings.span()
554        => "#[classattr] cannot be used with #[pyo3(warn)]"
555    );
556
557    let name = &spec.name;
558    let fncall = if py_arg.is_some() {
559        quote!(function(py))
560    } else {
561        quote!(function())
562    };
563
564    let wrapper_ident = format_ident!("__pymethod_{}__", name);
565    let python_name = spec.null_terminated_python_name(ctx);
566    let body = quotes::ok_wrap(fncall, ctx);
567
568    let associated_method = quote! {
569        fn #wrapper_ident(py: #pyo3_path::Python<'_>) -> #pyo3_path::PyResult<#pyo3_path::PyObject> {
570            let function = #cls::#name; // Shadow the method name to avoid #3017
571            let result = #body;
572            #pyo3_path::impl_::wrap::converter(&result).map_into_pyobject(py, result)
573        }
574    };
575
576    let method_def = quote! {
577        #pyo3_path::impl_::pyclass::MaybeRuntimePyMethodDef::Static(
578            #pyo3_path::impl_::pymethods::PyMethodDefType::ClassAttribute({
579                #pyo3_path::impl_::pymethods::PyClassAttributeDef::new(
580                    #python_name,
581                    #cls::#wrapper_ident
582                )
583            })
584        )
585    };
586
587    Ok(MethodAndMethodDef {
588        associated_method,
589        method_def,
590    })
591}
592
593fn impl_call_setter(
594    cls: &syn::Type,
595    spec: &FnSpec<'_>,
596    self_type: &SelfType,
597    holders: &mut Holders,
598    ctx: &Ctx,
599) -> syn::Result<TokenStream> {
600    let (py_arg, args) = split_off_python_arg(&spec.signature.arguments);
601    let slf = self_type.receiver(cls, ExtractErrorMode::Raise, holders, ctx);
602
603    if args.is_empty() {
604        bail_spanned!(spec.name.span() => "setter function expected to have one argument");
605    } else if args.len() > 1 {
606        bail_spanned!(
607            args[1].ty().span() =>
608            "setter function can have at most two arguments ([pyo3::Python,] and value)"
609        );
610    }
611
612    let name = &spec.name;
613    let fncall = if py_arg.is_some() {
614        quote!(#cls::#name(#slf, py, _val))
615    } else {
616        quote!(#cls::#name(#slf, _val))
617    };
618
619    Ok(fncall)
620}
621
622// Used here for PropertyType::Function, used in pyclass for descriptors.
623pub fn impl_py_setter_def(
624    cls: &syn::Type,
625    property_type: PropertyType<'_>,
626    ctx: &Ctx,
627) -> Result<MethodAndMethodDef> {
628    let Ctx { pyo3_path, .. } = ctx;
629    let python_name = property_type.null_terminated_python_name(ctx)?;
630    let doc = property_type.doc(ctx);
631    let mut holders = Holders::new();
632    let setter_impl = match property_type {
633        PropertyType::Descriptor {
634            field_index, field, ..
635        } => {
636            let slf = SelfType::Receiver {
637                mutable: true,
638                span: Span::call_site(),
639            }
640            .receiver(cls, ExtractErrorMode::Raise, &mut holders, ctx);
641            if let Some(ident) = &field.ident {
642                // named struct field
643                quote!({ #slf.#ident = _val; })
644            } else {
645                // tuple struct field
646                let index = syn::Index::from(field_index);
647                quote!({ #slf.#index = _val; })
648            }
649        }
650        PropertyType::Function {
651            spec, self_type, ..
652        } => impl_call_setter(cls, spec, self_type, &mut holders, ctx)?,
653    };
654
655    let wrapper_ident = match property_type {
656        PropertyType::Descriptor {
657            field: syn::Field {
658                ident: Some(ident), ..
659            },
660            ..
661        } => {
662            format_ident!("__pymethod_set_{}__", ident)
663        }
664        PropertyType::Descriptor { field_index, .. } => {
665            format_ident!("__pymethod_set_field_{}__", field_index)
666        }
667        PropertyType::Function { spec, .. } => {
668            format_ident!("__pymethod_set_{}__", spec.name)
669        }
670    };
671
672    let extract = match &property_type {
673        PropertyType::Function { spec, .. } => {
674            let (_, args) = split_off_python_arg(&spec.signature.arguments);
675            let value_arg = &args[0];
676            let (from_py_with, ident) =
677                if let Some(from_py_with) = &value_arg.from_py_with().as_ref().map(|f| &f.value) {
678                    let ident = syn::Ident::new("from_py_with", from_py_with.span());
679                    (
680                        quote_spanned! { from_py_with.span() =>
681                            let #ident = #from_py_with;
682                        },
683                        ident,
684                    )
685                } else {
686                    (quote!(), syn::Ident::new("dummy", Span::call_site()))
687                };
688
689            let arg = if let FnArg::Regular(arg) = &value_arg {
690                arg
691            } else {
692                bail_spanned!(value_arg.name().span() => "The #[setter] value argument can't be *args, **kwargs or `cancel_handle`.");
693            };
694
695            let extract = impl_regular_arg_param(
696                arg,
697                ident,
698                quote!(::std::option::Option::Some(_value.into())),
699                &mut holders,
700                ctx,
701            );
702
703            quote! {
704                #from_py_with
705                let _val = #extract;
706            }
707        }
708        PropertyType::Descriptor { field, .. } => {
709            let span = field.ty.span();
710            let name = field
711                .ident
712                .as_ref()
713                .map(|i| i.to_string())
714                .unwrap_or_default();
715
716            let holder = holders.push_holder(span);
717            let ty = field.ty.clone().elide_lifetimes();
718            quote! {
719                #[allow(unused_imports)]
720                use #pyo3_path::impl_::pyclass::Probe as _;
721                let _val = #pyo3_path::impl_::extract_argument::extract_argument::<
722                    _,
723                    { #pyo3_path::impl_::pyclass::IsOption::<#ty>::VALUE }
724                >(_value.into(), &mut #holder, #name)?;
725            }
726        }
727    };
728
729    let mut cfg_attrs = TokenStream::new();
730    if let PropertyType::Descriptor { field, .. } = &property_type {
731        for attr in field
732            .attrs
733            .iter()
734            .filter(|attr| attr.path().is_ident("cfg"))
735        {
736            attr.to_tokens(&mut cfg_attrs);
737        }
738    }
739
740    let warnings = if let PropertyType::Function { spec, .. } = &property_type {
741        spec.warnings.build_py_warning(ctx)
742    } else {
743        quote!()
744    };
745
746    let init_holders = holders.init_holders(ctx);
747    let associated_method = quote! {
748        #cfg_attrs
749        unsafe fn #wrapper_ident(
750            py: #pyo3_path::Python<'_>,
751            _slf: *mut #pyo3_path::ffi::PyObject,
752            _value: *mut #pyo3_path::ffi::PyObject,
753        ) -> #pyo3_path::PyResult<::std::os::raw::c_int> {
754            use ::std::convert::Into;
755            let _value = #pyo3_path::impl_::pymethods::BoundRef::ref_from_ptr_or_opt(py, &_value)
756                .ok_or_else(|| {
757                    #pyo3_path::exceptions::PyAttributeError::new_err("can't delete attribute")
758                })?;
759            #init_holders
760            #extract
761            #warnings
762            let result = #setter_impl;
763            #pyo3_path::impl_::callback::convert(py, result)
764        }
765    };
766
767    let method_def = quote! {
768        #cfg_attrs
769        #pyo3_path::impl_::pyclass::MaybeRuntimePyMethodDef::Static(
770            #pyo3_path::impl_::pymethods::PyMethodDefType::Setter(
771                #pyo3_path::impl_::pymethods::PySetterDef::new(
772                    #python_name,
773                    #cls::#wrapper_ident,
774                    #doc
775                )
776            )
777        )
778    };
779
780    Ok(MethodAndMethodDef {
781        associated_method,
782        method_def,
783    })
784}
785
786fn impl_call_getter(
787    cls: &syn::Type,
788    spec: &FnSpec<'_>,
789    self_type: &SelfType,
790    holders: &mut Holders,
791    ctx: &Ctx,
792) -> syn::Result<TokenStream> {
793    let (py_arg, args) = split_off_python_arg(&spec.signature.arguments);
794    let slf = self_type.receiver(cls, ExtractErrorMode::Raise, holders, ctx);
795    ensure_spanned!(
796        args.is_empty(),
797        args[0].ty().span() => "getter function can only have one argument (of type pyo3::Python)"
798    );
799
800    let name = &spec.name;
801    let fncall = if py_arg.is_some() {
802        quote!(#cls::#name(#slf, py))
803    } else {
804        quote!(#cls::#name(#slf))
805    };
806
807    Ok(fncall)
808}
809
810// Used here for PropertyType::Function, used in pyclass for descriptors.
811pub fn impl_py_getter_def(
812    cls: &syn::Type,
813    property_type: PropertyType<'_>,
814    ctx: &Ctx,
815) -> Result<MethodAndMethodDef> {
816    let Ctx { pyo3_path, .. } = ctx;
817    let python_name = property_type.null_terminated_python_name(ctx)?;
818    let doc = property_type.doc(ctx);
819
820    let mut cfg_attrs = TokenStream::new();
821    if let PropertyType::Descriptor { field, .. } = &property_type {
822        for attr in field
823            .attrs
824            .iter()
825            .filter(|attr| attr.path().is_ident("cfg"))
826        {
827            attr.to_tokens(&mut cfg_attrs);
828        }
829    }
830
831    let mut holders = Holders::new();
832    match property_type {
833        PropertyType::Descriptor {
834            field_index, field, ..
835        } => {
836            let ty = &field.ty;
837            let field = if let Some(ident) = &field.ident {
838                ident.to_token_stream()
839            } else {
840                syn::Index::from(field_index).to_token_stream()
841            };
842
843            // TODO: on MSRV 1.77+, we can use `::std::mem::offset_of!` here, and it should
844            // make it possible for the `MaybeRuntimePyMethodDef` to be a `Static` variant.
845            let generator = quote_spanned! { ty.span() =>
846                #pyo3_path::impl_::pyclass::MaybeRuntimePyMethodDef::Runtime(
847                    || GENERATOR.generate(#python_name, #doc)
848                )
849            };
850            // This is separate so that the unsafe below does not inherit the span and thus does not
851            // trigger the `unsafe_code` lint
852            let method_def = quote! {
853                #cfg_attrs
854                {
855                    #[allow(unused_imports)]  // might not be used if all probes are positve
856                    use #pyo3_path::impl_::pyclass::Probe;
857
858                    struct Offset;
859                    unsafe impl #pyo3_path::impl_::pyclass::OffsetCalculator<#cls, #ty> for Offset {
860                        fn offset() -> usize {
861                            #pyo3_path::impl_::pyclass::class_offset::<#cls>() +
862                            #pyo3_path::impl_::pyclass::offset_of!(#cls, #field)
863                        }
864                    }
865
866                    const GENERATOR: #pyo3_path::impl_::pyclass::PyClassGetterGenerator::<
867                        #cls,
868                        #ty,
869                        Offset,
870                        { #pyo3_path::impl_::pyclass::IsPyT::<#ty>::VALUE },
871                        { #pyo3_path::impl_::pyclass::IsIntoPyObjectRef::<#ty>::VALUE },
872                        { #pyo3_path::impl_::pyclass::IsIntoPyObject::<#ty>::VALUE },
873                    > = unsafe { #pyo3_path::impl_::pyclass::PyClassGetterGenerator::new() };
874                    #generator
875                }
876            };
877
878            Ok(MethodAndMethodDef {
879                associated_method: quote! {},
880                method_def,
881            })
882        }
883        // Forward to `IntoPyCallbackOutput`, to handle `#[getter]`s returning results.
884        PropertyType::Function {
885            spec, self_type, ..
886        } => {
887            let wrapper_ident = format_ident!("__pymethod_get_{}__", spec.name);
888            let call = impl_call_getter(cls, spec, self_type, &mut holders, ctx)?;
889            let body = quote! {
890                #pyo3_path::impl_::callback::convert(py, #call)
891            };
892
893            let init_holders = holders.init_holders(ctx);
894            let warnings = spec.warnings.build_py_warning(ctx);
895
896            let associated_method = quote! {
897                #cfg_attrs
898                unsafe fn #wrapper_ident(
899                    py: #pyo3_path::Python<'_>,
900                    _slf: *mut #pyo3_path::ffi::PyObject
901                ) -> #pyo3_path::PyResult<*mut #pyo3_path::ffi::PyObject> {
902                    #init_holders
903                    #warnings
904                    let result = #body;
905                    result
906                }
907            };
908
909            let method_def = quote! {
910                #cfg_attrs
911                #pyo3_path::impl_::pyclass::MaybeRuntimePyMethodDef::Static(
912                    #pyo3_path::impl_::pymethods::PyMethodDefType::Getter(
913                        #pyo3_path::impl_::pymethods::PyGetterDef::new(
914                            #python_name,
915                            #cls::#wrapper_ident,
916                            #doc
917                        )
918                    )
919                )
920            };
921
922            Ok(MethodAndMethodDef {
923                associated_method,
924                method_def,
925            })
926        }
927    }
928}
929
930/// Split an argument of pyo3::Python from the front of the arg list, if present
931fn split_off_python_arg<'a, 'b>(args: &'a [FnArg<'b>]) -> (Option<&'a PyArg<'b>>, &'a [FnArg<'b>]) {
932    match args {
933        [FnArg::Py(py), args @ ..] => (Some(py), args),
934        args => (None, args),
935    }
936}
937
938pub enum PropertyType<'a> {
939    Descriptor {
940        field_index: usize,
941        field: &'a syn::Field,
942        python_name: Option<&'a NameAttribute>,
943        renaming_rule: Option<RenamingRule>,
944    },
945    Function {
946        self_type: &'a SelfType,
947        spec: &'a FnSpec<'a>,
948        doc: PythonDoc,
949    },
950}
951
952impl PropertyType<'_> {
953    fn null_terminated_python_name(&self, ctx: &Ctx) -> Result<LitCStr> {
954        match self {
955            PropertyType::Descriptor {
956                field,
957                python_name,
958                renaming_rule,
959                ..
960            } => {
961                let name = match (python_name, &field.ident) {
962                    (Some(name), _) => name.value.0.to_string(),
963                    (None, Some(field_name)) => {
964                        let mut name = field_name.unraw().to_string();
965                        if let Some(rule) = renaming_rule {
966                            name = utils::apply_renaming_rule(*rule, &name);
967                        }
968                        name
969                    }
970                    (None, None) => {
971                        bail_spanned!(field.span() => "`get` and `set` with tuple struct fields require `name`");
972                    }
973                };
974                let name = CString::new(name).unwrap();
975                Ok(LitCStr::new(name, field.span(), ctx))
976            }
977            PropertyType::Function { spec, .. } => Ok(spec.null_terminated_python_name(ctx)),
978        }
979    }
980
981    fn doc(&self, ctx: &Ctx) -> Cow<'_, PythonDoc> {
982        match self {
983            PropertyType::Descriptor { field, .. } => {
984                Cow::Owned(utils::get_doc(&field.attrs, None, ctx))
985            }
986            PropertyType::Function { doc, .. } => Cow::Borrowed(doc),
987        }
988    }
989}
990
991pub const __STR__: SlotDef = SlotDef::new("Py_tp_str", "reprfunc");
992pub const __REPR__: SlotDef = SlotDef::new("Py_tp_repr", "reprfunc");
993pub const __HASH__: SlotDef = SlotDef::new("Py_tp_hash", "hashfunc")
994    .ret_ty(Ty::PyHashT)
995    .return_conversion(TokenGenerator(
996        |Ctx { pyo3_path, .. }: &Ctx| quote! { #pyo3_path::impl_::callback::HashCallbackOutput },
997    ));
998pub const __RICHCMP__: SlotDef = SlotDef::new("Py_tp_richcompare", "richcmpfunc")
999    .extract_error_mode(ExtractErrorMode::NotImplemented)
1000    .arguments(&[Ty::Object, Ty::CompareOp]);
1001const __GET__: SlotDef = SlotDef::new("Py_tp_descr_get", "descrgetfunc")
1002    .arguments(&[Ty::MaybeNullObject, Ty::MaybeNullObject]);
1003const __ITER__: SlotDef = SlotDef::new("Py_tp_iter", "getiterfunc");
1004const __NEXT__: SlotDef = SlotDef::new("Py_tp_iternext", "iternextfunc")
1005    .return_specialized_conversion(
1006        TokenGenerator(|_| quote! { IterBaseKind, IterOptionKind, IterResultOptionKind }),
1007        TokenGenerator(|_| quote! { iter_tag }),
1008    );
1009const __AWAIT__: SlotDef = SlotDef::new("Py_am_await", "unaryfunc");
1010const __AITER__: SlotDef = SlotDef::new("Py_am_aiter", "unaryfunc");
1011const __ANEXT__: SlotDef = SlotDef::new("Py_am_anext", "unaryfunc").return_specialized_conversion(
1012    TokenGenerator(
1013        |_| quote! { AsyncIterBaseKind, AsyncIterOptionKind, AsyncIterResultOptionKind },
1014    ),
1015    TokenGenerator(|_| quote! { async_iter_tag }),
1016);
1017pub const __LEN__: SlotDef = SlotDef::new("Py_mp_length", "lenfunc").ret_ty(Ty::PySsizeT);
1018const __CONTAINS__: SlotDef = SlotDef::new("Py_sq_contains", "objobjproc")
1019    .arguments(&[Ty::Object])
1020    .ret_ty(Ty::Int);
1021const __CONCAT__: SlotDef = SlotDef::new("Py_sq_concat", "binaryfunc").arguments(&[Ty::Object]);
1022const __REPEAT__: SlotDef = SlotDef::new("Py_sq_repeat", "ssizeargfunc").arguments(&[Ty::PySsizeT]);
1023const __INPLACE_CONCAT__: SlotDef =
1024    SlotDef::new("Py_sq_concat", "binaryfunc").arguments(&[Ty::Object]);
1025const __INPLACE_REPEAT__: SlotDef =
1026    SlotDef::new("Py_sq_repeat", "ssizeargfunc").arguments(&[Ty::PySsizeT]);
1027pub const __GETITEM__: SlotDef =
1028    SlotDef::new("Py_mp_subscript", "binaryfunc").arguments(&[Ty::Object]);
1029
1030const __POS__: SlotDef = SlotDef::new("Py_nb_positive", "unaryfunc");
1031const __NEG__: SlotDef = SlotDef::new("Py_nb_negative", "unaryfunc");
1032const __ABS__: SlotDef = SlotDef::new("Py_nb_absolute", "unaryfunc");
1033const __INVERT__: SlotDef = SlotDef::new("Py_nb_invert", "unaryfunc");
1034const __INDEX__: SlotDef = SlotDef::new("Py_nb_index", "unaryfunc");
1035pub const __INT__: SlotDef = SlotDef::new("Py_nb_int", "unaryfunc");
1036const __FLOAT__: SlotDef = SlotDef::new("Py_nb_float", "unaryfunc");
1037const __BOOL__: SlotDef = SlotDef::new("Py_nb_bool", "inquiry").ret_ty(Ty::Int);
1038
1039const __IADD__: SlotDef = SlotDef::new("Py_nb_inplace_add", "binaryfunc")
1040    .arguments(&[Ty::Object])
1041    .extract_error_mode(ExtractErrorMode::NotImplemented)
1042    .return_self();
1043const __ISUB__: SlotDef = SlotDef::new("Py_nb_inplace_subtract", "binaryfunc")
1044    .arguments(&[Ty::Object])
1045    .extract_error_mode(ExtractErrorMode::NotImplemented)
1046    .return_self();
1047const __IMUL__: SlotDef = SlotDef::new("Py_nb_inplace_multiply", "binaryfunc")
1048    .arguments(&[Ty::Object])
1049    .extract_error_mode(ExtractErrorMode::NotImplemented)
1050    .return_self();
1051const __IMATMUL__: SlotDef = SlotDef::new("Py_nb_inplace_matrix_multiply", "binaryfunc")
1052    .arguments(&[Ty::Object])
1053    .extract_error_mode(ExtractErrorMode::NotImplemented)
1054    .return_self();
1055const __ITRUEDIV__: SlotDef = SlotDef::new("Py_nb_inplace_true_divide", "binaryfunc")
1056    .arguments(&[Ty::Object])
1057    .extract_error_mode(ExtractErrorMode::NotImplemented)
1058    .return_self();
1059const __IFLOORDIV__: SlotDef = SlotDef::new("Py_nb_inplace_floor_divide", "binaryfunc")
1060    .arguments(&[Ty::Object])
1061    .extract_error_mode(ExtractErrorMode::NotImplemented)
1062    .return_self();
1063const __IMOD__: SlotDef = SlotDef::new("Py_nb_inplace_remainder", "binaryfunc")
1064    .arguments(&[Ty::Object])
1065    .extract_error_mode(ExtractErrorMode::NotImplemented)
1066    .return_self();
1067const __IPOW__: SlotDef = SlotDef::new("Py_nb_inplace_power", "ipowfunc")
1068    .arguments(&[Ty::Object, Ty::IPowModulo])
1069    .extract_error_mode(ExtractErrorMode::NotImplemented)
1070    .return_self();
1071const __ILSHIFT__: SlotDef = SlotDef::new("Py_nb_inplace_lshift", "binaryfunc")
1072    .arguments(&[Ty::Object])
1073    .extract_error_mode(ExtractErrorMode::NotImplemented)
1074    .return_self();
1075const __IRSHIFT__: SlotDef = SlotDef::new("Py_nb_inplace_rshift", "binaryfunc")
1076    .arguments(&[Ty::Object])
1077    .extract_error_mode(ExtractErrorMode::NotImplemented)
1078    .return_self();
1079const __IAND__: SlotDef = SlotDef::new("Py_nb_inplace_and", "binaryfunc")
1080    .arguments(&[Ty::Object])
1081    .extract_error_mode(ExtractErrorMode::NotImplemented)
1082    .return_self();
1083const __IXOR__: SlotDef = SlotDef::new("Py_nb_inplace_xor", "binaryfunc")
1084    .arguments(&[Ty::Object])
1085    .extract_error_mode(ExtractErrorMode::NotImplemented)
1086    .return_self();
1087const __IOR__: SlotDef = SlotDef::new("Py_nb_inplace_or", "binaryfunc")
1088    .arguments(&[Ty::Object])
1089    .extract_error_mode(ExtractErrorMode::NotImplemented)
1090    .return_self();
1091const __GETBUFFER__: SlotDef = SlotDef::new("Py_bf_getbuffer", "getbufferproc")
1092    .arguments(&[Ty::PyBuffer, Ty::Int])
1093    .ret_ty(Ty::Int)
1094    .require_unsafe();
1095const __RELEASEBUFFER__: SlotDef = SlotDef::new("Py_bf_releasebuffer", "releasebufferproc")
1096    .arguments(&[Ty::PyBuffer])
1097    .ret_ty(Ty::Void)
1098    .require_unsafe();
1099const __CLEAR__: SlotDef = SlotDef::new("Py_tp_clear", "inquiry")
1100    .arguments(&[])
1101    .ret_ty(Ty::Int);
1102
1103#[derive(Clone, Copy)]
1104enum Ty {
1105    Object,
1106    MaybeNullObject,
1107    NonNullObject,
1108    IPowModulo,
1109    CompareOp,
1110    Int,
1111    PyHashT,
1112    PySsizeT,
1113    Void,
1114    PyBuffer,
1115}
1116
1117impl Ty {
1118    fn ffi_type(self, ctx: &Ctx) -> TokenStream {
1119        let Ctx {
1120            pyo3_path,
1121            output_span,
1122        } = ctx;
1123        let pyo3_path = pyo3_path.to_tokens_spanned(*output_span);
1124        match self {
1125            Ty::Object | Ty::MaybeNullObject => quote! { *mut #pyo3_path::ffi::PyObject },
1126            Ty::NonNullObject => quote! { ::std::ptr::NonNull<#pyo3_path::ffi::PyObject> },
1127            Ty::IPowModulo => quote! { #pyo3_path::impl_::pymethods::IPowModulo },
1128            Ty::Int | Ty::CompareOp => quote! { ::std::os::raw::c_int },
1129            Ty::PyHashT => quote! { #pyo3_path::ffi::Py_hash_t },
1130            Ty::PySsizeT => quote! { #pyo3_path::ffi::Py_ssize_t },
1131            Ty::Void => quote! { () },
1132            Ty::PyBuffer => quote! { *mut #pyo3_path::ffi::Py_buffer },
1133        }
1134    }
1135
1136    fn extract(
1137        self,
1138        ident: &syn::Ident,
1139        arg: &FnArg<'_>,
1140        extract_error_mode: ExtractErrorMode,
1141        holders: &mut Holders,
1142        ctx: &Ctx,
1143    ) -> TokenStream {
1144        let Ctx { pyo3_path, .. } = ctx;
1145        match self {
1146            Ty::Object => extract_object(
1147                extract_error_mode,
1148                holders,
1149                arg,
1150                quote! { #ident },
1151                ctx
1152            ),
1153            Ty::MaybeNullObject => extract_object(
1154                extract_error_mode,
1155                holders,
1156                arg,
1157                quote! {
1158                    if #ident.is_null() {
1159                        #pyo3_path::ffi::Py_None()
1160                    } else {
1161                        #ident
1162                    }
1163                },
1164                ctx
1165            ),
1166            Ty::NonNullObject => extract_object(
1167                extract_error_mode,
1168                holders,
1169                arg,
1170                quote! { #ident.as_ptr() },
1171                ctx
1172            ),
1173            Ty::IPowModulo => extract_object(
1174                extract_error_mode,
1175                holders,
1176                arg,
1177                quote! { #ident.as_ptr() },
1178                ctx
1179            ),
1180            Ty::CompareOp => extract_error_mode.handle_error(
1181                quote! {
1182                    #pyo3_path::class::basic::CompareOp::from_raw(#ident)
1183                        .ok_or_else(|| #pyo3_path::exceptions::PyValueError::new_err("invalid comparison operator"))
1184                },
1185                ctx
1186            ),
1187            Ty::PySsizeT => {
1188                let ty = arg.ty();
1189                extract_error_mode.handle_error(
1190                    quote! {
1191                            ::std::convert::TryInto::<#ty>::try_into(#ident).map_err(|e| #pyo3_path::exceptions::PyValueError::new_err(e.to_string()))
1192                    },
1193                    ctx
1194                )
1195            }
1196            // Just pass other types through unmodified
1197            Ty::PyBuffer | Ty::Int | Ty::PyHashT | Ty::Void => quote! { #ident },
1198        }
1199    }
1200}
1201
1202fn extract_object(
1203    extract_error_mode: ExtractErrorMode,
1204    holders: &mut Holders,
1205    arg: &FnArg<'_>,
1206    source_ptr: TokenStream,
1207    ctx: &Ctx,
1208) -> TokenStream {
1209    let Ctx { pyo3_path, .. } = ctx;
1210    let name = arg.name().unraw().to_string();
1211
1212    let extract = if let Some(FromPyWithAttribute {
1213        kw,
1214        value: extractor,
1215    }) = arg.from_py_with()
1216    {
1217        let extractor = quote_spanned! { kw.span =>
1218            { let from_py_with: fn(_) -> _ = #extractor; from_py_with }
1219        };
1220
1221        quote! {
1222            #pyo3_path::impl_::extract_argument::from_py_with(
1223                unsafe { #pyo3_path::impl_::pymethods::BoundRef::ref_from_ptr(py, &#source_ptr).0 },
1224                #name,
1225                #extractor,
1226            )
1227        }
1228    } else {
1229        let holder = holders.push_holder(Span::call_site());
1230        let ty = arg.ty().clone().elide_lifetimes();
1231        quote! {{
1232            #[allow(unused_imports)]
1233            use #pyo3_path::impl_::pyclass::Probe as _;
1234            #pyo3_path::impl_::extract_argument::extract_argument::<
1235                _,
1236                { #pyo3_path::impl_::pyclass::IsOption::<#ty>::VALUE }
1237            >(
1238                unsafe { #pyo3_path::impl_::pymethods::BoundRef::ref_from_ptr(py, &#source_ptr).0 },
1239                &mut #holder,
1240                #name
1241            )
1242        }}
1243    };
1244
1245    let extracted = extract_error_mode.handle_error(extract, ctx);
1246    quote!(#extracted)
1247}
1248
1249enum ReturnMode {
1250    ReturnSelf,
1251    Conversion(TokenGenerator),
1252    SpecializedConversion(TokenGenerator, TokenGenerator),
1253}
1254
1255impl ReturnMode {
1256    fn return_call_output(&self, call: TokenStream, ctx: &Ctx) -> TokenStream {
1257        let Ctx { pyo3_path, .. } = ctx;
1258        match self {
1259            ReturnMode::Conversion(conversion) => {
1260                let conversion = TokenGeneratorCtx(*conversion, ctx);
1261                quote! {
1262                    let _result: #pyo3_path::PyResult<#conversion> = #pyo3_path::impl_::callback::convert(py, #call);
1263                    #pyo3_path::impl_::callback::convert(py, _result)
1264                }
1265            }
1266            ReturnMode::SpecializedConversion(traits, tag) => {
1267                let traits = TokenGeneratorCtx(*traits, ctx);
1268                let tag = TokenGeneratorCtx(*tag, ctx);
1269                quote! {
1270                    let _result = #call;
1271                    use #pyo3_path::impl_::pymethods::{#traits};
1272                    (&_result).#tag().convert(py, _result)
1273                }
1274            }
1275            ReturnMode::ReturnSelf => quote! {
1276                let _result: #pyo3_path::PyResult<()> = #pyo3_path::impl_::callback::convert(py, #call);
1277                _result?;
1278                #pyo3_path::ffi::Py_XINCREF(_raw_slf);
1279                ::std::result::Result::Ok(_raw_slf)
1280            },
1281        }
1282    }
1283}
1284
1285pub struct SlotDef {
1286    slot: StaticIdent,
1287    func_ty: StaticIdent,
1288    arguments: &'static [Ty],
1289    ret_ty: Ty,
1290    extract_error_mode: ExtractErrorMode,
1291    return_mode: Option<ReturnMode>,
1292    require_unsafe: bool,
1293}
1294
1295const NO_ARGUMENTS: &[Ty] = &[];
1296
1297impl SlotDef {
1298    const fn new(slot: &'static str, func_ty: &'static str) -> Self {
1299        SlotDef {
1300            slot: StaticIdent(slot),
1301            func_ty: StaticIdent(func_ty),
1302            arguments: NO_ARGUMENTS,
1303            ret_ty: Ty::Object,
1304            extract_error_mode: ExtractErrorMode::Raise,
1305            return_mode: None,
1306            require_unsafe: false,
1307        }
1308    }
1309
1310    const fn arguments(mut self, arguments: &'static [Ty]) -> Self {
1311        self.arguments = arguments;
1312        self
1313    }
1314
1315    const fn ret_ty(mut self, ret_ty: Ty) -> Self {
1316        self.ret_ty = ret_ty;
1317        self
1318    }
1319
1320    const fn return_conversion(mut self, return_conversion: TokenGenerator) -> Self {
1321        self.return_mode = Some(ReturnMode::Conversion(return_conversion));
1322        self
1323    }
1324
1325    const fn return_specialized_conversion(
1326        mut self,
1327        traits: TokenGenerator,
1328        tag: TokenGenerator,
1329    ) -> Self {
1330        self.return_mode = Some(ReturnMode::SpecializedConversion(traits, tag));
1331        self
1332    }
1333
1334    const fn extract_error_mode(mut self, extract_error_mode: ExtractErrorMode) -> Self {
1335        self.extract_error_mode = extract_error_mode;
1336        self
1337    }
1338
1339    const fn return_self(mut self) -> Self {
1340        self.return_mode = Some(ReturnMode::ReturnSelf);
1341        self
1342    }
1343
1344    const fn require_unsafe(mut self) -> Self {
1345        self.require_unsafe = true;
1346        self
1347    }
1348
1349    pub fn generate_type_slot(
1350        &self,
1351        cls: &syn::Type,
1352        spec: &FnSpec<'_>,
1353        method_name: &str,
1354        ctx: &Ctx,
1355    ) -> Result<MethodAndSlotDef> {
1356        let Ctx { pyo3_path, .. } = ctx;
1357        let SlotDef {
1358            slot,
1359            func_ty,
1360            arguments,
1361            extract_error_mode,
1362            ret_ty,
1363            return_mode,
1364            require_unsafe,
1365        } = self;
1366        if *require_unsafe {
1367            ensure_spanned!(
1368                spec.unsafety.is_some(),
1369                spec.name.span() => format!("`{}` must be `unsafe fn`", method_name)
1370            );
1371        }
1372        let arg_types: &Vec<_> = &arguments.iter().map(|arg| arg.ffi_type(ctx)).collect();
1373        let arg_idents: &Vec<_> = &(0..arguments.len())
1374            .map(|i| format_ident!("arg{}", i))
1375            .collect();
1376        let wrapper_ident = format_ident!("__pymethod_{}__", method_name);
1377        let ret_ty = ret_ty.ffi_type(ctx);
1378        let mut holders = Holders::new();
1379        let body = generate_method_body(
1380            cls,
1381            spec,
1382            arguments,
1383            *extract_error_mode,
1384            &mut holders,
1385            return_mode.as_ref(),
1386            ctx,
1387        )?;
1388        let name = spec.name;
1389        let holders = holders.init_holders(ctx);
1390        let associated_method = quote! {
1391            #[allow(non_snake_case)]
1392            unsafe fn #wrapper_ident(
1393                py: #pyo3_path::Python<'_>,
1394                _raw_slf: *mut #pyo3_path::ffi::PyObject,
1395                #(#arg_idents: #arg_types),*
1396            ) -> #pyo3_path::PyResult<#ret_ty> {
1397                let function = #cls::#name; // Shadow the method name to avoid #3017
1398                let _slf = _raw_slf;
1399                #holders
1400                #body
1401            }
1402        };
1403        let slot_def = quote! {{
1404            unsafe extern "C" fn trampoline(
1405                _slf: *mut #pyo3_path::ffi::PyObject,
1406                #(#arg_idents: #arg_types),*
1407            ) -> #ret_ty
1408            {
1409                #pyo3_path::impl_::trampoline:: #func_ty (
1410                    _slf,
1411                    #(#arg_idents,)*
1412                    #cls::#wrapper_ident
1413                )
1414            }
1415
1416            #pyo3_path::ffi::PyType_Slot {
1417                slot: #pyo3_path::ffi::#slot,
1418                pfunc: trampoline as #pyo3_path::ffi::#func_ty as _
1419            }
1420        }};
1421        Ok(MethodAndSlotDef {
1422            associated_method,
1423            slot_def,
1424        })
1425    }
1426}
1427
1428fn generate_method_body(
1429    cls: &syn::Type,
1430    spec: &FnSpec<'_>,
1431    arguments: &[Ty],
1432    extract_error_mode: ExtractErrorMode,
1433    holders: &mut Holders,
1434    return_mode: Option<&ReturnMode>,
1435    ctx: &Ctx,
1436) -> Result<TokenStream> {
1437    let Ctx { pyo3_path, .. } = ctx;
1438    let self_arg = spec
1439        .tp
1440        .self_arg(Some(cls), extract_error_mode, holders, ctx);
1441    let rust_name = spec.name;
1442    let args = extract_proto_arguments(spec, arguments, extract_error_mode, holders, ctx)?;
1443    let call = quote! { #cls::#rust_name(#self_arg #(#args),*) };
1444    let body = if let Some(return_mode) = return_mode {
1445        return_mode.return_call_output(call, ctx)
1446    } else {
1447        quote! {
1448            let result = #call;
1449            #pyo3_path::impl_::callback::convert(py, result)
1450        }
1451    };
1452    let warnings = spec.warnings.build_py_warning(ctx);
1453
1454    Ok(quote! {
1455        #warnings
1456        #body
1457    })
1458}
1459
1460struct SlotFragmentDef {
1461    fragment: &'static str,
1462    arguments: &'static [Ty],
1463    extract_error_mode: ExtractErrorMode,
1464    ret_ty: Ty,
1465}
1466
1467impl SlotFragmentDef {
1468    const fn new(fragment: &'static str, arguments: &'static [Ty]) -> Self {
1469        SlotFragmentDef {
1470            fragment,
1471            arguments,
1472            extract_error_mode: ExtractErrorMode::Raise,
1473            ret_ty: Ty::Void,
1474        }
1475    }
1476
1477    const fn extract_error_mode(mut self, extract_error_mode: ExtractErrorMode) -> Self {
1478        self.extract_error_mode = extract_error_mode;
1479        self
1480    }
1481
1482    const fn ret_ty(mut self, ret_ty: Ty) -> Self {
1483        self.ret_ty = ret_ty;
1484        self
1485    }
1486
1487    fn generate_pyproto_fragment(
1488        &self,
1489        cls: &syn::Type,
1490        spec: &FnSpec<'_>,
1491        ctx: &Ctx,
1492    ) -> Result<TokenStream> {
1493        let Ctx { pyo3_path, .. } = ctx;
1494        let SlotFragmentDef {
1495            fragment,
1496            arguments,
1497            extract_error_mode,
1498            ret_ty,
1499        } = self;
1500        let fragment_trait = format_ident!("PyClass{}SlotFragment", fragment);
1501        let method = syn::Ident::new(fragment, Span::call_site());
1502        let wrapper_ident = format_ident!("__pymethod_{}__", fragment);
1503        let arg_types: &Vec<_> = &arguments.iter().map(|arg| arg.ffi_type(ctx)).collect();
1504        let arg_idents: &Vec<_> = &(0..arguments.len())
1505            .map(|i| format_ident!("arg{}", i))
1506            .collect();
1507        let mut holders = Holders::new();
1508        let body = generate_method_body(
1509            cls,
1510            spec,
1511            arguments,
1512            *extract_error_mode,
1513            &mut holders,
1514            None,
1515            ctx,
1516        )?;
1517        let ret_ty = ret_ty.ffi_type(ctx);
1518        let holders = holders.init_holders(ctx);
1519        Ok(quote! {
1520            impl #cls {
1521                #[allow(non_snake_case)]
1522                unsafe fn #wrapper_ident(
1523                    py: #pyo3_path::Python,
1524                    _raw_slf: *mut #pyo3_path::ffi::PyObject,
1525                    #(#arg_idents: #arg_types),*
1526                ) -> #pyo3_path::PyResult<#ret_ty> {
1527                    let _slf = _raw_slf;
1528                    #holders
1529                    #body
1530                }
1531            }
1532
1533            impl #pyo3_path::impl_::pyclass::#fragment_trait<#cls> for #pyo3_path::impl_::pyclass::PyClassImplCollector<#cls> {
1534
1535                #[inline]
1536                unsafe fn #method(
1537                    self,
1538                    py: #pyo3_path::Python,
1539                    _raw_slf: *mut #pyo3_path::ffi::PyObject,
1540                    #(#arg_idents: #arg_types),*
1541                ) -> #pyo3_path::PyResult<#ret_ty> {
1542                    #cls::#wrapper_ident(py, _raw_slf, #(#arg_idents),*)
1543                }
1544            }
1545        })
1546    }
1547}
1548
1549const __GETATTRIBUTE__: SlotFragmentDef =
1550    SlotFragmentDef::new("__getattribute__", &[Ty::Object]).ret_ty(Ty::Object);
1551const __GETATTR__: SlotFragmentDef =
1552    SlotFragmentDef::new("__getattr__", &[Ty::Object]).ret_ty(Ty::Object);
1553const __SETATTR__: SlotFragmentDef =
1554    SlotFragmentDef::new("__setattr__", &[Ty::Object, Ty::NonNullObject]);
1555const __DELATTR__: SlotFragmentDef = SlotFragmentDef::new("__delattr__", &[Ty::Object]);
1556const __SET__: SlotFragmentDef = SlotFragmentDef::new("__set__", &[Ty::Object, Ty::NonNullObject]);
1557const __DELETE__: SlotFragmentDef = SlotFragmentDef::new("__delete__", &[Ty::Object]);
1558const __SETITEM__: SlotFragmentDef =
1559    SlotFragmentDef::new("__setitem__", &[Ty::Object, Ty::NonNullObject]);
1560const __DELITEM__: SlotFragmentDef = SlotFragmentDef::new("__delitem__", &[Ty::Object]);
1561
1562macro_rules! binary_num_slot_fragment_def {
1563    ($ident:ident, $name:literal) => {
1564        const $ident: SlotFragmentDef = SlotFragmentDef::new($name, &[Ty::Object])
1565            .extract_error_mode(ExtractErrorMode::NotImplemented)
1566            .ret_ty(Ty::Object);
1567    };
1568}
1569
1570binary_num_slot_fragment_def!(__ADD__, "__add__");
1571binary_num_slot_fragment_def!(__RADD__, "__radd__");
1572binary_num_slot_fragment_def!(__SUB__, "__sub__");
1573binary_num_slot_fragment_def!(__RSUB__, "__rsub__");
1574binary_num_slot_fragment_def!(__MUL__, "__mul__");
1575binary_num_slot_fragment_def!(__RMUL__, "__rmul__");
1576binary_num_slot_fragment_def!(__MATMUL__, "__matmul__");
1577binary_num_slot_fragment_def!(__RMATMUL__, "__rmatmul__");
1578binary_num_slot_fragment_def!(__FLOORDIV__, "__floordiv__");
1579binary_num_slot_fragment_def!(__RFLOORDIV__, "__rfloordiv__");
1580binary_num_slot_fragment_def!(__TRUEDIV__, "__truediv__");
1581binary_num_slot_fragment_def!(__RTRUEDIV__, "__rtruediv__");
1582binary_num_slot_fragment_def!(__DIVMOD__, "__divmod__");
1583binary_num_slot_fragment_def!(__RDIVMOD__, "__rdivmod__");
1584binary_num_slot_fragment_def!(__MOD__, "__mod__");
1585binary_num_slot_fragment_def!(__RMOD__, "__rmod__");
1586binary_num_slot_fragment_def!(__LSHIFT__, "__lshift__");
1587binary_num_slot_fragment_def!(__RLSHIFT__, "__rlshift__");
1588binary_num_slot_fragment_def!(__RSHIFT__, "__rshift__");
1589binary_num_slot_fragment_def!(__RRSHIFT__, "__rrshift__");
1590binary_num_slot_fragment_def!(__AND__, "__and__");
1591binary_num_slot_fragment_def!(__RAND__, "__rand__");
1592binary_num_slot_fragment_def!(__XOR__, "__xor__");
1593binary_num_slot_fragment_def!(__RXOR__, "__rxor__");
1594binary_num_slot_fragment_def!(__OR__, "__or__");
1595binary_num_slot_fragment_def!(__ROR__, "__ror__");
1596
1597const __POW__: SlotFragmentDef = SlotFragmentDef::new("__pow__", &[Ty::Object, Ty::Object])
1598    .extract_error_mode(ExtractErrorMode::NotImplemented)
1599    .ret_ty(Ty::Object);
1600const __RPOW__: SlotFragmentDef = SlotFragmentDef::new("__rpow__", &[Ty::Object, Ty::Object])
1601    .extract_error_mode(ExtractErrorMode::NotImplemented)
1602    .ret_ty(Ty::Object);
1603
1604const __LT__: SlotFragmentDef = SlotFragmentDef::new("__lt__", &[Ty::Object])
1605    .extract_error_mode(ExtractErrorMode::NotImplemented)
1606    .ret_ty(Ty::Object);
1607const __LE__: SlotFragmentDef = SlotFragmentDef::new("__le__", &[Ty::Object])
1608    .extract_error_mode(ExtractErrorMode::NotImplemented)
1609    .ret_ty(Ty::Object);
1610const __EQ__: SlotFragmentDef = SlotFragmentDef::new("__eq__", &[Ty::Object])
1611    .extract_error_mode(ExtractErrorMode::NotImplemented)
1612    .ret_ty(Ty::Object);
1613const __NE__: SlotFragmentDef = SlotFragmentDef::new("__ne__", &[Ty::Object])
1614    .extract_error_mode(ExtractErrorMode::NotImplemented)
1615    .ret_ty(Ty::Object);
1616const __GT__: SlotFragmentDef = SlotFragmentDef::new("__gt__", &[Ty::Object])
1617    .extract_error_mode(ExtractErrorMode::NotImplemented)
1618    .ret_ty(Ty::Object);
1619const __GE__: SlotFragmentDef = SlotFragmentDef::new("__ge__", &[Ty::Object])
1620    .extract_error_mode(ExtractErrorMode::NotImplemented)
1621    .ret_ty(Ty::Object);
1622
1623fn extract_proto_arguments(
1624    spec: &FnSpec<'_>,
1625    proto_args: &[Ty],
1626    extract_error_mode: ExtractErrorMode,
1627    holders: &mut Holders,
1628    ctx: &Ctx,
1629) -> Result<Vec<TokenStream>> {
1630    let mut args = Vec::with_capacity(spec.signature.arguments.len());
1631    let mut non_python_args = 0;
1632
1633    for arg in &spec.signature.arguments {
1634        if let FnArg::Py(..) = arg {
1635            args.push(quote! { py });
1636        } else {
1637            let ident = syn::Ident::new(&format!("arg{non_python_args}"), Span::call_site());
1638            let conversions = proto_args.get(non_python_args)
1639                .ok_or_else(|| err_spanned!(arg.ty().span() => format!("Expected at most {} non-python arguments", proto_args.len())))?
1640                .extract(&ident, arg, extract_error_mode, holders, ctx);
1641            non_python_args += 1;
1642            args.push(conversions);
1643        }
1644    }
1645
1646    if non_python_args != proto_args.len() {
1647        bail_spanned!(spec.name.span() => format!("Expected {} arguments, got {}", proto_args.len(), non_python_args));
1648    }
1649    Ok(args)
1650}
1651
1652struct StaticIdent(&'static str);
1653
1654impl ToTokens for StaticIdent {
1655    fn to_tokens(&self, tokens: &mut TokenStream) {
1656        syn::Ident::new(self.0, Span::call_site()).to_tokens(tokens)
1657    }
1658}
1659
1660#[derive(Clone, Copy)]
1661struct TokenGenerator(fn(&Ctx) -> TokenStream);
1662
1663struct TokenGeneratorCtx<'ctx>(TokenGenerator, &'ctx Ctx);
1664
1665impl ToTokens for TokenGeneratorCtx<'_> {
1666    fn to_tokens(&self, tokens: &mut TokenStream) {
1667        let Self(TokenGenerator(gen), ctx) = self;
1668        (gen)(ctx).to_tokens(tokens)
1669    }
1670}
pyo3_macros_backend/pymethod.rs

pyo3_macros_backend/
pymethod.rs
