Align symtable flag names with CPython by ShaharNaveh · Pull Request #8184 · RustPython/RustPython

ShaharNaveh · 2026-06-27T12:01:08Z

Closes #xxxx
This PR follows our AI policy

Summary

Summary by CodeRabbit

Bug Fixes
- Improved symbol tracking so imported names, parameters, globals, nonlocals, and comprehension variables are recognized more reliably.
- Fixed several scope-related cases, including free-class handling and nested comprehension behavior.
- Updated the Python symbol table API so flags and symbol properties report more consistent results.

coderabbitai · 2026-06-27T12:01:22Z

📝 Walkthrough

Walkthrough

This PR renames symbol-table flags to the new DEF_*/USE scheme across codegen, symbol analysis, and Python symtable bindings. It updates comprehension, free-class, global/nonlocal, parameter, and annotation handling, plus matching tests and exported constants.

Changes

Symbol flag migration across analyzer, codegen, and symtable API

Layer / File(s)	Summary
Flag contract and exported predicates `crates/codegen/src/symboltable.rs`, `crates/vm/src/stdlib/_symtable.rs`	`SymbolFlags` constants and `Symbol` predicates now use the new `DEF_*`/`USE` bits, and `DEF_BOUND` is derived from those updated flags.
Synthesized symbols and closures `crates/codegen/src/symboltable.rs`	`.format` symbols, comprehension inlining, free-class propagation, and related tests now use `DEF_PARAM`, `DEF_COMP_CELL`, `USE`, and `DEF_FREE_CLASS`.
Global and nonlocal registration `crates/codegen/src/symboltable.rs`	`analyze_symbol()`, `extend_namedexpr_scope()`, and `register_name()` now validate and assign `DEF_GLOBAL`, `DEF_NONLOCAL`, `DEF_LOCAL`, `DEF_PARAM`, and `DEF_TYPE_PARAM`.
Compile-time flag consumers `crates/codegen/src/compile.rs`	Compile-time symbol checks now read `DEF_IMPORT`, `DEF_FREE_CLASS`, `DEF_COMP_CELL`, `DEF_GLOBAL`, `DEF_PARAM`, and `DEF_LOCAL` in import, scope, and local-slot logic.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~60 minutes

Possibly related PRs

RustPython/RustPython#7631: Overlaps on comprehension inlining and COMP_CELL/free-variable handling in crates/codegen/src/symboltable.rs.

Suggested reviewers

youknowone

Poem

🐇 I hopped through bits from old to new,
DEF_flags sparkled in the dew.
Comprehensions twitched, then ran quite free,
And globals bowed with symmetry.
A soft nose-nudge: hop, hop, hooray!

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 76.92% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: renaming symtable flags to CPython-aligned names.
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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github-actions · 2026-06-27T12:01:59Z

📦 Library Dependencies

The following Lib/ modules were modified. Here are their dependencies:

[x] lib: cpython/Lib/symtable.py
[x] test: cpython/Lib/test/test_symtable.py (TODO: 11)

dependencies:

symtable

dependent tests: (2 tests)

symtable: test_inspect test_symtable

Legend:

[+] path exists in CPython
[x] up-to-date, [ ] outdated

coderabbitai

Actionable comments posted: 1

🤖 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/codegen/src/symboltable.rs`:
- Around line 311-317: `SymbolFlags::DEF_BOUND` is currently mixing in the
RustPython-only `ITER` bit, which leaks into the public `_symtable.DEF_BOUND`
export and breaks CPython compatibility. Update the `DEF_BOUND` definition in
`symboltable.rs` to include only the CPython-aligned flags, and keep `ITER`
restricted to internal bound-check logic elsewhere in the symbol table handling.

🪄 Autofix (Beta)

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

⚙️ Run configuration

Configuration used: Path: .coderabbit.yml

Review profile: CHILL

Plan: Pro

Run ID: 4c981d47-0be7-4e02-802a-f6f0517ef402

📥 Commits

Reviewing files that changed from the base of the PR and between 0009dd6 and 560b9cb.

⛔ Files ignored due to path filters (1)

Lib/test/test_symtable.py is excluded by !Lib/**

📒 Files selected for processing (3)

crates/codegen/src/compile.rs
crates/codegen/src/symboltable.rs
crates/vm/src/stdlib/_symtable.rs

coderabbitai · 2026-06-27T12:06:50Z

+        const DEF_BOUND = (
+            Self::DEF_LOCAL.bits()
+            | Self::DEF_PARAM.bits()
+            | Self::DEF_IMPORT.bits()
+            | Self::ITER.bits()
+            | Self::DEF_TYPE_PARAM.bits()
+        );


🗄️ Data Integrity & Integration | 🟠 Major | ⚡ Quick win

Keep RustPython-only ITER out of the CPython DEF_BOUND mask.

Line 315 folds the internal ITER bit into DEF_BOUND, and _symtable now exports SymbolFlags::DEF_BOUND.bits() directly. That makes the public _symtable.DEF_BOUND value include a RustPython-specific flag, breaking the CPython-aligned flag contract. Keep DEF_BOUND CPython-compatible and include ITER only in internal bound checks.

Suggested fix

const DEF_BOUND = ( Self::DEF_LOCAL.bits() | Self::DEF_PARAM.bits() | Self::DEF_IMPORT.bits() - | Self::ITER.bits() | Self::DEF_TYPE_PARAM.bits() );

pub const fn is_bound(&self) -> bool { - self.flags.intersects(SymbolFlags::DEF_BOUND) + self.flags + .intersects(SymbolFlags::DEF_BOUND | SymbolFlags::ITER) }

📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change

const DEF_BOUND = (

Self::DEF_LOCAL.bits()

| Self::DEF_PARAM.bits()

| Self::DEF_IMPORT.bits()

| Self::ITER.bits()

| Self::DEF_TYPE_PARAM.bits()

);

const DEF_BOUND = (

Self::DEF_LOCAL.bits()

| Self::DEF_PARAM.bits()

| Self::DEF_IMPORT.bits()

| Self::DEF_TYPE_PARAM.bits()

);

🤖 Prompt for 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. In `@crates/codegen/src/symboltable.rs` around lines 311 - 317, `SymbolFlags::DEF_BOUND` is currently mixing in the RustPython-only `ITER` bit, which leaks into the public `_symtable.DEF_BOUND` export and breaks CPython compatibility. Update the `DEF_BOUND` definition in `symboltable.rs` to include only the CPython-aligned flags, and keep `ITER` restricted to internal bound-check logic elsewhere in the symbol table handling.

youknowone · 2026-06-30T14:37:17Z

+        const DEF_GLOBAL   = 1;
+        const DEF_LOCAL    = 2;
+        const DEF_PARAM    = 2 << 1;
+        const DEF_NONLOCAL = 2 << 2;
+        const USE          = 2 << 3;


Suggested change

const DEF_GLOBAL = 1;

const DEF_LOCAL = 2;

const DEF_PARAM = 2 << 1;

const DEF_NONLOCAL = 2 << 2;

const USE = 2 << 3;

const DEF_GLOBAL = 1 << 0;

const DEF_LOCAL = 1 << 1;

const DEF_PARAM = 1 << 2;

const DEF_NONLOCAL = 1 << 3;

const USE = 1 << 4;

if 2 << n better than this?

I've matched those values to be 1:1 like they're defined over at CPython for it to not be confusing. I'd rather keep it like this if you're okay with it

ShaharNaveh added 12 commits June 27, 2026 14:09

ASSIGNED -> DEF_LOCAL

7a53285

GLOBAL -> DEF_GLOBAL

d84717a

REFERENCED -> USE

a75c55b

PARAMETER -> DEF_PARAM

70e834c

expose symbol flags directly as a pyattr

fd2a934

FREE_CLASS -> DEF_FREE_CLASS

5d36d38

IMPORTED -> DEF_IMPORT

c3b424c

ANNOTATED -> DEF_ANNOT

3c2480b

DEF_COMP_ITER DEF_COMP_CELL DEF_TYPE_PARAM

d25ca85

DEF_NONLOCAL DEF_BOUND

037f05e

Align flag values

6678195

unmark passing tests

560b9cb

coderabbitai Bot reviewed Jun 27, 2026

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youknowone reviewed Jun 30, 2026

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Align symtable flag names with CPython#8184

Align symtable flag names with CPython#8184
ShaharNaveh wants to merge 12 commits into
RustPython:mainfrom
ShaharNaveh:symtable-symbolflag-names

ShaharNaveh commented Jun 27, 2026 •

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Summary

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github-actions Bot commented Jun 27, 2026

📦 Library Dependencies

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ShaharNaveh commented Jun 27, 2026 •

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