no_std clippy#7043

youknowone

Summary by CodeRabbit

Release Notes

Refactor
- Reduced reliance on the standard library to improve compatibility with restricted/no-std environments and broaden platform support.
- Multiple internal imports and memory/pointer handling paths migrated to core/alloc equivalents with no behavioral changes.
Chores
- Enabled additional Clippy lints (including suspicious and correctness) and clarified lint annotations for cross-platform code.
Compatibility
- Small, targeted public type adjustments to threading/module state to align with the allocator/core changes.

coderabbitai

📝 Walkthrough

Walkthrough

This PR enables additional Clippy lints and systematically replaces many std:: usages with core:: and alloc:: equivalents across the codebase (memory, pointers, atomics, collections, FFI and threading types) to align with no-std/no-std-like constraints.

Changes

Cohort / File(s)	Summary
Clippy Configuration `Cargo.toml`	Uncommented/enabled clippy lints: `alloc_instead_of_core`, `std_instead_of_alloc`, `std_instead_of_core`; added `suspicious` and `correctness` lint groups set to `warn`.
Memory & Pointer core:: Migration `crates/.../codegen/src/compile.rs`, `crates/common/src/crt_fd.rs`, `crates/common/src/fileutils.rs`, `crates/stdlib/src/mmap.rs`, `crates/vm/src/stdlib/nt.rs`, `crates/vm/src/stdlib/sys.rs`, `crates/vm/src/windows.rs`, `crates/vm/src/stdlib/winapi.rs`, `crates/vm/src/stdlib/winreg.rs`	Replaced `std::mem::`, `std::ptr::`, `std::mem::MaybeUninit`, `std::mem::zeroed`, and `std::mem::size_of*` usages with `core::` equivalents for initialization, sizing, and null pointers.
Slices / Iterators / Formatting Migration `crates/stdlib/src/_sqlite3.rs`, `crates/stdlib/src/math.rs`, `crates/stdlib/src/socket.rs`, `crates/stdlib/src/ssl.rs`, `crates/vm/src/stdlib/io.rs`, `crates/vm/src/stdlib/msvcrt.rs`	Swapped `std::slice`, `std::iter`, `std::fmt` and related calls with `core::slice`, `core::iter`, `core::fmt` equivalents (including Debug impl updates).
Atomic Types Migration `crates/stdlib/src/_asyncio.rs`, `crates/stdlib/src/posixsubprocess.rs`, `crates/vm/src/builtins/template.rs`, `crates/vm/src/stdlib/_abc.rs`, `crates/vm/src/stdlib/signal.rs`, `crates/vm/src/vm/interpreter.rs`, `crates/vm/src/vm/mod.rs`	Replaced `std::sync::atomic::{...}` imports and usages with `core::sync::atomic` counterparts; updated struct fields/initializers and Ordering references (notably `PyTemplateIter` fields).
Arc/Weak & Collections Migration `crates/stdlib/src/multiprocessing.rs`, `crates/stdlib/src/overlapped.rs`, `crates/stdlib/src/thread.rs`, `crates/vm/src/vm/thread.rs`, `crates/vm/src/vm/interpreter.rs`, `crates/vm/src/vm/mod.rs`	Replaced `std::sync::Arc`/`Weak` with `alloc::sync::{Arc, Weak}` and moved `std::collections::BTreeMap` uses to `alloc::collections::BTreeMap`/local imports; several public struct fields/types updated accordingly (thread-related types).
FFI / CString / c_void Migration `crates/common/src/fileutils.rs`, `crates/stdlib/src/multiprocessing.rs`, `crates/stdlib/src/os.rs`, `crates/vm/src/stdlib/ctypes.rs`	Replaced `std::ffi::CString` with `alloc::ffi::CString` in allocation contexts; switched `std::ffi::c_void` to `core::ffi::c_void` in function-pointer signatures.
Duration / Time types Migration `crates/stdlib/src/ssl.rs`, `crates/vm/src/stdlib/time.rs`	Replaced `std::time::Duration` with `core::time::Duration` in function parameters/usage and corresponding duration computations.
Clippy allow attributes & minor annotations `crates/vm/src/stdlib/ctypes/base.rs`, `crates/vm/src/stdlib/ctypes/function.rs`, `crates/vm/src/stdlib/ctypes/pointer.rs`, `crates/vm/src/stdlib/ctypes/simple.rs`, `crates/vm/src/stdlib/io.rs`	Added/expanded clippy allow attributes (e.g., `clippy::useless_conversion`, `clippy::unnecessary_cast`) with reason strings for platform-specific wchar_t conversions and added small comment/lint tweaks.
Small std→core/alloc swaps in VM internals `crates/vm/src/builtins/function.rs`, `crates/vm/src/builtins/tuple.rs`, `crates/vm/src/frame.rs`, `crates/vm/src/signal.rs`, `crates/vm/src/builtins/template.rs`, `crates/vm/src/stdlib/ctypes/*`, `crates/vm/src/stdlib/io.rs`, `crates/vm/src/stdlib/msvcrt.rs`	Replaced scattered `std::` usages (e.g., `mem::take`, `mem::replace`, `hint::unreachable_unchecked`, `cell::Cell`, `ptr::null_mut`) with `core::` equivalents; atomic and field signature adjustments where applicable.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~75 minutes

Possibly related PRs

finish no_std clippy #6587: Similar no-std/core+alloc migration across many stdlib modules (strong overlap in approach and affected files).
Fix asyncio related compiler/library issues #6837: Touches crates/codegen/src/compile.rs and may conflict with changes around t-string/template handling.
Upgrade threading to 3.13.11; sys.setprofile & impl more threading #6691: Changes threading types/APIs (ThreadHandle/ShutdownEntry/Arc/Weak) similar to the thread-related type migrations here.

Suggested reviewers

ShaharNaveh
arihant2math

"🐰 I hopped through code at break of dawn,
Swapped std for core before the lawn,
Pointers neat and atomics bright,
Clippy nods as I take flight —
A tiny hop, a cleaner night."

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Title check	❓ Inconclusive	The title 'no_std clippy' is vague and generic, using non-descriptive terms that don't clearly convey the changeset's main objective despite referencing a related initiative.	Revise the title to be more specific and descriptive of the primary changes, such as 'Replace std library imports with core/alloc equivalents for no_std compatibility' or reference the issue more explicitly.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	Docstring coverage is 96.75% which is sufficient. The required threshold is 80.00%.

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github-actions

Code has been automatically formatted

The code in this PR has been formatted using:

cargo fmt --all
Please pull the latest changes before pushing again:

git pull origin no_std

coderabbitai

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@crates/vm/src/stdlib/thread.rs`:
- Around line 20-23: The import is pulling fmt from alloc which triggers the
alloc_instead_of_core lint; change the use to import fmt from core (so types
like fmt::Debug, fmt::Formatter, fmt::Result come from core::fmt) while keeping
sync::{Arc, Weak} from alloc; update the use statement that currently reads use
alloc::{ fmt, sync::{Arc, Weak}, }; to import core::fmt instead and leave Arc
and Weak unchanged, and ensure any references to fmt types (Debug, Formatter,
Result) remain correct.

🧹 Nitpick comments (1)

crates/vm/src/stdlib/signal.rs (1)
31-31: Nit: use the existing atomic alias for brevity.

Line 15 already imports core::sync::atomic::{self, Ordering}, so the fully qualified core::sync::atomic::AtomicBool can be simplified.
♻️ Suggested simplification
-            static WAKEUP_IS_SOCKET: core::sync::atomic::AtomicBool = core::sync::atomic::AtomicBool::new(false);
+            static WAKEUP_IS_SOCKET: atomic::AtomicBool = atomic::AtomicBool::new(false);

ShaharNaveh

Great!

youknowone force-pushed the no_std branch from 1c50a3e to 987295c Compare February 8, 2026 03:43

youknowone force-pushed the no_std branch 5 times, most recently from 44bf6bf to da9ad35 Compare February 8, 2026 06:21

ShaharNaveh reviewed Feb 8, 2026

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youknowone force-pushed the no_std branch from da9ad35 to b351f28 Compare February 8, 2026 07:17

youknowone marked this pull request as ready for review February 8, 2026 07:18

youknowone requested a review from ShaharNaveh February 8, 2026 07:18

youknowone enabled auto-merge (squash) February 8, 2026 07:18

ShaharNaveh requested changes Feb 8, 2026

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coderabbitai Bot reviewed Feb 8, 2026

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youknowone requested a review from ShaharNaveh February 8, 2026 07:32

no_std clippy

360fb1f

youknowone force-pushed the no_std branch from b351f28 to 360fb1f Compare February 8, 2026 07:36

Auto-format: cargo fmt --all

4e8cf97

ShaharNaveh approved these changes Feb 8, 2026

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youknowone disabled auto-merge February 8, 2026 07:49

youknowone deleted the no_std branch February 8, 2026 07:49

This was referenced Feb 8, 2026

no_std for wtf8, sre_engine, compiler-core, literal #7051

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no_std for common, pylib, codegen #7056

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no_std clippy#7043