Add more object functions to c-api by bschoenmaeckers · Pull Request #8042 · RustPython/RustPython

bschoenmaeckers · 2026-06-04T09:41:52Z

Summary by CodeRabbit

New Features
- Expanded C-API for object introspection and operations: attribute access, type/module info, callable checks, rich comparisons, directory listing, weak-ref clearing, and generic dict get/set for objects.
Chores
- Previously internal object helpers made public via the builtins surface for broader reuse and a new public method to clear object weak references.

coderabbitai · 2026-06-04T09:42:06Z

No actionable comments were generated in the recent review. 🎉

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📥 Commits

Reviewing files that changed from the base of the PR and between 0597510 and 9331963.

📒 Files selected for processing (1)

crates/capi/src/object.rs

🚧 Files skipped from review as they are similar to previous changes (1)

crates/capi/src/object.rs

📝 Walkthrough

Walkthrough

Adds multiple C-API object/type helpers (type module-name, optional/generic attr access, rich compare, callable/dir, generic dict get/set, weakref clearing) and makes VM object dict utilities and a weakref-clear method public and re-exported.

Changes

C-API Object Introspection and Manipulation Functions

Layer / File(s)	Summary
VM object utilities public API `crates/vm/src/builtins/object.rs`, `crates/vm/src/builtins/mod.rs`, `crates/vm/src/object/core.rs`	`object_get_dict` and `object_generic_set_dict` changed from `pub(crate)` to `pub` and are re-exported; `PyObject::clear_weak_refs()` added to clear an object's weakref list.
C-API object and type introspection functions `crates/capi/src/object.rs`	Adds `PyType_GetModuleName`, `PyObject_GetOptionalAttr`, `PyObject_HasAttrWithError`, `PyObject_GenericGetAttr`, `PyObject_RichCompare`, `PyCallable_Check`, `PyObject_ClearWeakRefs`, `PyObject_Dir`, `PyObject_GenericGetDict`, and `PyObject_GenericSetDict`; updates FFI imports and includes a disabled test module.

Sequence Diagram(s)

sequenceDiagram
  participant CCaller
  participant CApiLayer
  participant VMBuiltins
  participant VMCore
  CCaller->>CApiLayer: PyObject_GetOptionalAttr(obj, name, out)
  CApiLayer->>VMCore: generic_getattr / has_attr
  VMCore-->>CApiLayer: attribute pointer / NULL
  CCaller->>CApiLayer: PyObject_GenericSetDict(obj, value, ctx)
  CApiLayer->>VMBuiltins: object_generic_set_dict(obj, value, vm)
  VMBuiltins-->>CApiLayer: status (0/1)
  CCaller->>CApiLayer: PyObject_ClearWeakRefs(obj)
  CApiLayer->>VMCore: PyObject::clear_weak_refs()
  VMCore-->>CApiLayer: cleared

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

RustPython/RustPython#7872: Overlapping C-API object/attribute helper extensions and placement of PyObject_IsTrue.
RustPython/RustPython#7925: Related type-introspection C-API additions (type name/module helpers).
RustPython/RustPython#7871: Additional PyType_* C-API entry point changes related to type introspection.

Suggested reviewers

youknowone
ShaharNaveh

Poem

🐰 I hopped through code with nimble paws,

Exposed some attrs and cleared weak laws,
Dicts now open, comparisons sing,
C callers knock at every ring,
A rabbit cheers — the API claws!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding multiple new object functions to the C-API export surface in crates/capi/src/object.rs.
Docstring Coverage	✅ Passed	Docstring coverage is 84.21% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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coderabbitai

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@crates/capi/src/object.rs`:
- Around line 273-279: PyObject_Dir currently dereferences obj unconditionally;
add a fast-path at the start of PyObject_Dir to check if obj.is_null() and
immediately return std::ptr::null_mut() (matching CPython semantics of returning
NULL without setting an exception) before calling with_vm or dereferencing; keep
the existing with_vm(... unsafe { &*obj }.to_owned().dir(vm).map(|list|
list.into_ref(&vm.ctx)) logic for the non-null path so behavior of to_owned(),
dir(), and into_ref() is unchanged.
- Around line 302-311: The function PyObject_GenericSetDict currently
unconditionally dereferences value causing UB when the descriptor protocol
passes NULL to signal deletion; change the code to check value with
NonNull::new(value) and map to PySetterValue::Delete when NULL (or
PySetterValue::Assign(non_null.to_owned()) when non-null) before calling
object_generic_set_dict so deletion flows through correctly and avoids
dereferencing a NULL pointer.

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Fix all unresolved CodeRabbit comments on this PR:

Push a commit to this branch (recommended)
Create a new PR with the fixes

ℹ️ Review info

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Configuration used: Path: .coderabbit.yml

Review profile: CHILL

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Run ID: a7337516-4056-43f8-814e-250e06407d98

📥 Commits

Reviewing files that changed from the base of the PR and between 51c97b9 and 998109f.

📒 Files selected for processing (4)

crates/capi/src/object.rs
crates/vm/src/builtins/mod.rs
crates/vm/src/builtins/object.rs
crates/vm/src/object/core.rs

Add more object functions to c-api

998109f

coderabbitai Bot reviewed Jun 4, 2026

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Comment thread crates/capi/src/object.rs

Comment thread crates/capi/src/object.rs

Review

0597510

bschoenmaeckers force-pushed the c-api-object branch from df865b4 to 0597510 Compare June 4, 2026 10:09

Add PyObject_HasAttrWithError

9331963

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Add more object functions to c-api#8042

Add more object functions to c-api#8042
bschoenmaeckers wants to merge 3 commits into
RustPython:mainfrom
bschoenmaeckers:c-api-object

bschoenmaeckers commented Jun 4, 2026 •

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