Walkthrough

Two new compile flags, PY_CF_OPTIMIZED_AST and PY_CF_TYPE_COMMENTS, were introduced and integrated into both the Rust and Python layers of the AST module. The compile flags mask was updated to include these flags. Additionally, a minor wording change was made to an error message in the constant literal handling.

Changes

Poem

Two flags hop in, with numbers so bright,
Now Python and Rust share compile-time delight.
Error words polished, a message anew—
The AST garden grows with something fresh too.
🐇✨ Flags and constants, all in a row,
CodeRabbit’s burrow continues to grow!

Configuration used: .coderabbit.yml
Review profile: CHILL
Plan: Pro

Reviewing files that changed from the base of the PR and between 4e0c1aa and 3dc2c9d.

• Lib/ast.py is excluded by !Lib/**
• Lib/test/test_ast.py is excluded by !Lib/**
• Lib/test/test_ast/__init__.py is excluded by !Lib/**
• Lib/test/test_ast/snippets.py is excluded by !Lib/**
• Lib/test/test_ast/test_ast.py is excluded by !Lib/**
• Lib/test/test_ast/utils.py is excluded by !Lib/**

• vm/src/stdlib/ast.rs (2 hunks)
• vm/src/stdlib/ast/constant.rs (1 hunks)
• vm/src/stdlib/ast/python.rs (2 hunks)

Instructions used from:

Sources:
📄 CodeRabbit Inference Engine

• .github/copilot-instructions.md

Learnt from: moreal
PR: RustPython/RustPython#5847
File: vm/src/stdlib/stat.rs:547-567
Timestamp: 2025-06-27T14:47:28.810Z
Learning: In RustPython's stat module implementation, platform-specific constants like SF_SUPPORTED and SF_SYNTHETIC should be conditionally declared only for the platforms where they're available (e.g., macOS), following CPython's approach of optional declaration using #ifdef checks rather than providing fallback values for other platforms.

Learnt from: moreal
PR: RustPython/RustPython#5847
File: vm/src/stdlib/stat.rs:547-567
Timestamp: 2025-06-27T14:47:28.810Z
Learning: In RustPython's stat module implementation, platform-specific constants like SF_SUPPORTED and SF_SYNTHETIC should be conditionally declared only for the platforms where they're available (e.g., macOS), following CPython's approach of optional declaration rather than providing fallback values for other platforms.

Learnt from: CR
PR: RustPython/RustPython#0
File: .github/copilot-instructions.md:0-0
Timestamp: 2025-07-19T03:16:56.511Z
Learning: Applies to Lib/test/**/*.py : When tests fail due to unsupported syntax, keep the test as `@unittest.expectedFailure`, document that it requires PEP 695 support, and focus on tests that can be fixed through Rust code changes only

Learnt from: moreal
PR: RustPython/RustPython#5847
File: vm/src/stdlib/stat.rs:547-567
Timestamp: 2025-06-27T14:47:28.810Z
Learning: In RustPython's stat module implementation, platform-specific constants like SF_SUPPORTED and SF_SYNTHETIC should be conditionally declared only for the platforms where they're available (e.g., macOS), following CPython's approach of optional declaration using #ifdef checks rather than providing fallback values for other platforms.

Learnt from: moreal
PR: RustPython/RustPython#5847
File: vm/src/stdlib/stat.rs:547-567
Timestamp: 2025-06-27T14:47:28.810Z
Learning: In RustPython's stat module implementation, platform-specific constants like SF_SUPPORTED and SF_SYNTHETIC should be conditionally declared only for the platforms where they're available (e.g., macOS), following CPython's approach of optional declaration rather than providing fallback values for other platforms.

Learnt from: CR
PR: RustPython/RustPython#0
File: .github/copilot-instructions.md:0-0
Timestamp: 2025-07-19T03:16:56.511Z
Learning: Applies to **/*.rs : Use the macro system (`pyclass`, `pymodule`, `pyfunction`, etc.) when implementing Python functionality in Rust

Learnt from: CR
PR: RustPython/RustPython#0
File: .github/copilot-instructions.md:0-0
Timestamp: 2025-07-19T03:16:56.511Z
Learning: Applies to Lib/**/*.py : Minimize modifications to CPython standard library files in `Lib/`

Learnt from: CR
PR: RustPython/RustPython#0
File: .github/copilot-instructions.md:0-0
Timestamp: 2025-07-19T03:16:56.511Z
Learning: Applies to Lib/test/**/*.py : When tests fail due to unsupported syntax, keep the test as `@unittest.expectedFailure`, document that it requires PEP 695 support, and focus on tests that can be fixed through Rust code changes only

Learnt from: moreal
PR: RustPython/RustPython#5847
File: vm/src/stdlib/stat.rs:547-567
Timestamp: 2025-06-27T14:47:28.810Z
Learning: In RustPython's stat module implementation, platform-specific constants like SF_SUPPORTED and SF_SYNTHETIC should be conditionally declared only for the platforms where they're available (e.g., macOS), following CPython's approach of optional declaration using #ifdef checks rather than providing fallback values for other platforms.

Learnt from: moreal
PR: RustPython/RustPython#5847
File: vm/src/stdlib/stat.rs:547-567
Timestamp: 2025-06-27T14:47:28.810Z
Learning: In RustPython's stat module implementation, platform-specific constants like SF_SUPPORTED and SF_SYNTHETIC should be conditionally declared only for the platforms where they're available (e.g., macOS), following CPython's approach of optional declaration rather than providing fallback values for other platforms.

Learnt from: CR
PR: RustPython/RustPython#0
File: .github/copilot-instructions.md:0-0
Timestamp: 2025-07-19T03:16:56.511Z
Learning: Applies to **/*.rs : Use the macro system (`pyclass`, `pymodule`, `pyfunction`, etc.) when implementing Python functionality in Rust

Learnt from: CR
PR: RustPython/RustPython#0
File: .github/copilot-instructions.md:0-0
Timestamp: 2025-07-19T03:16:56.511Z
Learning: Applies to Lib/test/**/*.py : When tests fail due to unsupported syntax, keep the test as `@unittest.expectedFailure`, document that it requires PEP 695 support, and focus on tests that can be fixed through Rust code changes only

vm/src/stdlib/ast.rs (2)

301-302: LGTM! New compile flags correctly defined.

The new compile flags PY_CF_OPTIMIZED_AST and PY_CF_TYPE_COMMENTS are properly defined with correct values that match CPython 3.13.5. The combination of 0x8000 | PY_COMPILE_FLAG_AST_ONLY for optimized AST is correct.

---

324-325: LGTM! Compile flags mask properly updated.

The new compile flags are correctly included in the PY_COMPILE_FLAGS_MASK, ensuring they are recognized by the compilation system.

vm/src/stdlib/ast/python.rs (2)

1-1: LGTM! Import statement correctly updated.

The new compile flag constants are properly imported from the parent module.

---

58-62: LGTM! Python module attributes properly exposed.

The new compile flags are correctly exposed as Python module attributes using the pyattr macro, following the same pattern as the existing PyCF_ONLY_AST attribute. This ensures the flags are accessible from Python code.

vm/src/stdlib/ast/constant.rs (1)

238-238: LGTM! Error message wording improved.

The change from "invalid type in Constant" to "got an invalid type in Constant" makes the error message more natural and readable, aligning with typical Python error message patterns.

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