Update libc to `0.2.182`#7247

ShaharNaveh

Summary by CodeRabbit

Chores
- Bumped libc dependency to 0.2.182.
- Expanded platform-specific POSIX constant coverage across many OS targets.
New Features
- Replaced ad-hoc constant extraction with a data-driven generation pipeline that derives libc version at runtime, fetches upstream sources, and formats output.
Stability
- Improved error reporting and output formatting for the platform-constant generation process.

coderabbitai

📝 Walkthrough

Walkthrough

Bumps the libc dependency, reorganizes and expands per-target libc symbol imports and cfg gating in the POSIX module, and replaces the hardcoded const-generation script with a TOML-driven, multi-target extraction pipeline that fetches upstream docs and formats generated Rust.

Changes

Cohort / File(s)	Summary
Dependency Update `Cargo.toml`	Bumped `libc` from `0.2.180` → `0.2.182`.
POSIX libc imports & cfgs `crates/vm/src/stdlib/posix.rs`	Reorganized and split libc symbol imports into finer-grained `#[cfg(...)]` blocks, added/relocated many OS-specific constants (scheduling, file flags, spawn items), introduced FreeBSD `SF_*` exposures. No public API signatures changed.
Const-generation script `scripts/libc_posix.py`	Replaced ad-hoc extraction with a data-driven pipeline: reads `Cargo.toml` for libc version, fetches upstream docs per-target, extracts constants, groups by cfgs, integrates extras, formats output with `rustfmt`. Added dataclasses `Cfg`, `Target`, helper functions (`rustfmt`, `extract_consts`, `consts_from_url`) and TARGETS configuration.

Sequence Diagram(s)

sequenceDiagram
    participant Dev as Developer / CI
    participant Script as scripts/libc_posix.py
    participant Cargo as Cargo.toml
    participant Remote as Upstream Docs
    participant Rustfmt as rustfmt
    participant Out as Generated Rust (posix.rs)

    Dev->>Script: invoke generation
    Script->>Cargo: read libc version from Cargo.toml
    Script->>Remote: fetch source pages for each TARGET
    Remote-->>Script: return HTML/text
    Script->>Script: extract constants, group by Cfg/Target, attach extras
    Script->>Rustfmt: format generated Rust code
    Rustfmt-->>Script: return formatted code
    Script->>Out: write cfg-tagged Rust blocks into posix.rs
    Script-->>Dev: exit (success or error)

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Possibly related PRs

Attempt to automate posix consts #6117: Directly touches scripts/libc_posix.py and crates/vm/src/stdlib/posix.rs for libc constant generation automation and posix import generation.
Update libc to 0.2.177 #6300: Overlaps updates to Cargo.toml, posix import rearrangements, and generation tooling for libc constants.
Update os constant to libc 0.2.180 & target cpython 3.14 #6917: Modifies scheduling-constant handling (e.g., SCHED_DEADLINE / SCHED_NORMAL) and libc exposure logic in posix-related code.

Suggested reviewers

youknowone

Poem

🐇 I nibble TOML, hop to fetch,
constants gathered, matched to each fetch.
Rustfmt tidies every cfg line,
flags aligned, platforms fine.
A joyful hop — generation's fresh! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'Update libc to `0.2.182`' directly aligns with the main change—a dependency version bump of libc from 0.2.180 to 0.2.182. While the PR includes substantial refactoring of the posix.rs file and the libc_posix.py script, the title focuses on the primary motivating change (the version update), which is appropriate for a concise PR title.

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Code has been automatically formatted

The code in this PR has been formatted using:

ruff format
Please pull the latest changes before pushing again:

git pull origin update-libc-0-2-182

coderabbitai

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@crates/vm/src/stdlib/posix.rs`:
- Around line 64-66: The cfg currently gating SCHED_DEADLINE and SCHED_NORMAL is
too narrow (only Android); change the attribute on the use/import of
SCHED_DEADLINE and SCHED_NORMAL in posix.rs from #[cfg(target_os = "android")]
to #[cfg(any(target_os = "android", target_os = "linux"))] so these constants
are available on Linux as well (match the pattern used for
SCHED_BATCH/SCHED_IDLE/SCHED_RESET_ON_FORK); update the cfg on the import that
references SCHED_DEADLINE and SCHED_NORMAL accordingly.

ℹ️ Review info

Configuration used: Path: .coderabbit.yml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 123b629 and 5248d83.

⛔ Files ignored due to path filters (1)

Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (2)

Cargo.toml
crates/vm/src/stdlib/posix.rs

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

Cargo.toml

coderabbitai

Actionable comments posted: 1

🧹 Nitpick comments (1)

scripts/libc_posix.py (1)

20-20: Use explicit UTF-8 when reading Cargo.toml.

Line 20 currently relies on platform default encoding; specifying UTF-8 avoids locale-dependent failures.

Proposed fix

-CARGO_TOML = tomllib.loads(CARGO_TOML_FILE.read_text())
+CARGO_TOML = tomllib.loads(CARGO_TOML_FILE.read_text(encoding="utf-8"))

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@scripts/libc_posix.py` at line 20, The code reads Cargo.toml using
CARGO_TOML_FILE.read_text() which uses the platform default encoding; change the
read to explicitly use UTF-8 so parsing is deterministic by calling read_text
with encoding="utf-8" (or open the file with encoding="utf-8" and pass the
content to tomllib.loads) and assign the result back to CARGO_TOML; update the
CARGO_TOML assignment that references CARGO_TOML_FILE to use the UTF-8-decoded
text.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@scripts/libc_posix.py`:
- Around line 163-165: The return type annotation of consts_from_url is
incorrect (currently "str") — update its annotation to match the actual returned
type from extract_consts, e.g. change the function signature to return
frozenset[str] (or typing.FrozenSet[str] if using typing imports) so it aligns
with CONSTS_PATTERN, EXCLUDE, and the extract_consts(...) return value used in
the implementation.

---

Nitpick comments:
In `@scripts/libc_posix.py`:
- Line 20: The code reads Cargo.toml using CARGO_TOML_FILE.read_text() which
uses the platform default encoding; change the read to explicitly use UTF-8 so
parsing is deterministic by calling read_text with encoding="utf-8" (or open the
file with encoding="utf-8" and pass the content to tomllib.loads) and assign the
result back to CARGO_TOML; update the CARGO_TOML assignment that references
CARGO_TOML_FILE to use the UTF-8-decoded text.

ℹ️ Review info

Configuration used: Path: .coderabbit.yml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 5248d83 and 2979d36.

⛔ Files ignored due to path filters (1)

Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (3)

Cargo.toml
crates/vm/src/stdlib/posix.rs
scripts/libc_posix.py

coderabbitai

Actionable comments posted: 1

🧹 Nitpick comments (1)

scripts/libc_posix.py (1)
235-235: Make import rendering deterministic before formatting.

Line 235 joins a set directly. Sorting here avoids nondeterministic intermediate output and avoids relying on formatter behavior for stable ordering.
Proposed fix
-        imports = ",".join(consts)
+        imports = ",".join(sorted(consts))
🤖 Prompt for AI Agents
Verify each finding against the current code and only fix it if needed.

In `@scripts/libc_posix.py` at line 235, The current code constructs imports by
joining consts directly which can be nondeterministic if consts is a set; make
the output deterministic by sorting before joining — replace the join over
consts with a join over sorted(consts) so the variable imports is produced in
stable, alphabetical order (referencing the consts collection and the imports
variable).

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@scripts/libc_posix.py`:
- Around line 179-184: The Python helper libc_posix.py calls
urllib.request.urlopen(url) without a timeout; since Python code should remain
unchanged, enforce a request timeout in the Rust caller that invokes this
script: locate the Rust code that spawns or invokes libc_posix.py (the
Command/process that passes the `url` to libc_posix.py) and wrap the child
process execution with a timeout (e.g., use std::process::Child + wait_timeout
crate or tokio::time::timeout for async) so the Python helper is killed if it
hangs, return a clear error to the caller; ensure the timeout value is
configurable or documented and that the child process is terminated (kill) on
timeout and proper errors are propagated to the calling code.

---

Nitpick comments:
In `@scripts/libc_posix.py`:
- Line 235: The current code constructs imports by joining consts directly which
can be nondeterministic if consts is a set; make the output deterministic by
sorting before joining — replace the join over consts with a join over
sorted(consts) so the variable imports is produced in stable, alphabetical order
(referencing the consts collection and the imports variable).

ℹ️ Review info

Configuration used: Path: .coderabbit.yml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 2979d36 and 7fe87cf.

📒 Files selected for processing (1)

scripts/libc_posix.py

* Update to libc 0.2.182, refactor update script * Fix typing

ShaharNaveh marked this pull request as ready for review February 28, 2026 14:34

ShaharNaveh force-pushed the update-libc-0-2-182 branch from 123b629 to 5248d83 Compare February 28, 2026 18:14

coderabbitai Bot reviewed Feb 28, 2026

View reviewed changes

Update to libc 0.2.182, refactor update script

2979d36

ShaharNaveh force-pushed the update-libc-0-2-182 branch from 8f895d3 to 2979d36 Compare March 3, 2026 15:38

coderabbitai Bot reviewed Mar 3, 2026

View reviewed changes

Fix typing

7fe87cf

coderabbitai Bot reviewed Mar 3, 2026

View reviewed changes

ShaharNaveh requested a review from youknowone March 4, 2026 06:39

youknowone approved these changes Mar 4, 2026

View reviewed changes

coderabbitai Bot mentioned this pull request Mar 12, 2026

Upgrade libc to 0.2.183 #7406

Merged

youknowone pushed a commit to youknowone/RustPython that referenced this pull request Mar 22, 2026

Update libc to 0.2.182 (RustPython#7247) …

ffce85a

* Update to libc 0.2.182, refactor update script * Fix typing

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Update libc to `0.2.182`#7247