rust/kernel/std_vendor.rs

Source file repositories/reference/linux-study-clean/rust/kernel/std_vendor.rs

File Facts

System
Linux kernel
Corpus path
rust/kernel/std_vendor.rs
Extension
.rs
Size
5274 bytes
Lines
165
Domain
Rust Kernel Layer
Bucket
Rust API Membrane
Inferred role
Rust Kernel Layer: implementation source
Status
source implementation candidate

Why This File Exists

Rust-side wrappers and abstractions around kernel C APIs, ownership contracts, allocation, synchronization, and module integration.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: Apache-2.0 OR MIT

//! Rust standard library vendored code.
//!
//! The contents of this file come from the Rust standard library, hosted in
//! the <https://github.com/rust-lang/rust> repository, licensed under
//! "Apache-2.0 OR MIT" and adapted for kernel use. For copyright details,
//! see <https://github.com/rust-lang/rust/blob/master/COPYRIGHT>.

/// [`std::dbg`], but using [`pr_info`] instead of [`eprintln`].
///
/// Prints and returns the value of a given expression for quick and dirty
/// debugging.
///
/// An example:
///
/// ```rust
/// let a = 2;
/// # #[expect(clippy::disallowed_macros)]
/// let b = dbg!(a * 2) + 1;
/// //      ^-- prints: [src/main.rs:3:9] a * 2 = 4
/// assert_eq!(b, 5);
/// ```
///
/// The macro works by using the `Debug` implementation of the type of
/// the given expression to print the value with [`printk`] along with the
/// source location of the macro invocation as well as the source code
/// of the expression.
///
/// Invoking the macro on an expression moves and takes ownership of it
/// before returning the evaluated expression unchanged. If the type
/// of the expression does not implement `Copy` and you don't want
/// to give up ownership, you can instead borrow with `dbg!(&expr)`
/// for some expression `expr`.
///
/// The `dbg!` macro works exactly the same in release builds.
/// This is useful when debugging issues that only occur in release
/// builds or when debugging in release mode is significantly faster.
///
/// Note that the macro is intended as a temporary debugging tool to be
/// used during development. Therefore, avoid committing `dbg!` macro
/// invocations into the kernel tree.
///
/// For debug output that is intended to be kept in the kernel tree,
/// use [`pr_debug`] and similar facilities instead.
///
/// # Stability
///
/// The exact output printed by this macro should not be relied upon
/// and is subject to future changes.
///
/// # Further examples
///
/// With a method call:
///
/// ```rust
/// # #[expect(clippy::disallowed_macros)]
/// fn foo(n: usize) {
///     if dbg!(n.checked_sub(4)).is_some() {
///         // ...
///     }
/// }
///
/// foo(3)
/// ```
///
/// This prints to the kernel log:
///
/// ```text,ignore
/// [src/main.rs:3:8] n.checked_sub(4) = None
/// ```
///
/// Naive factorial implementation:
///
/// ```rust
/// # #![expect(clippy::disallowed_macros)]
/// fn factorial(n: u32) -> u32 {
///     if dbg!(n <= 1) {
///         dbg!(1)
///     } else {
///         dbg!(n * factorial(n - 1))
///     }
/// }
///
/// dbg!(factorial(4));
/// ```
///
/// This prints to the kernel log:
///
/// ```text,ignore

Annotation

Implementation Notes