tracing/tracing-attributes
Eliza Weisman ac74ba0ca5 attributes: suppress clippy::suspicious_else without nop let (#1614)
Currently, `tracing-attributes` generates a `let _ = ();` in between the
`if tracing::level_enabled!(...) {}` and the function body. This is
intended to suppress the `clippy::suspicious_else_formatting` lint,
which is generated when an `if` is followed immediately by a block with
no whitespace in between. Since we can't add whitespace in the generated
code (as `quote` produces a stream of _rust tokens_, not text), we
can't suppress the lint without adding a no-op statement.

However, unfortunately, the no-op let triggers a _different_ lint
(`clippy::let_unit_value`), when `clippy::pedantic` is enabled. This is
kind of annoying for some users.

This branch changes the code to suppress the
`suspicious_else_formatting` lint using `#[allow(...)]` attributes,
instead. The warning is turned back on inside of user code, since users
probably want the warning.
2021-10-05 13:27:27 -07:00
..

Tracing — Structured, application-level diagnostics

tracing-attributes

Macro attributes for application-level tracing.

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Overview

tracing is a framework for instrumenting Rust programs to collect structured, event-based diagnostic information. This crate provides the #[instrument] attribute for automatically instrumenting functions using tracing.

Note that this macro is also re-exported by the main tracing crate.

Compiler support: requires rustc 1.42+

Usage

First, add this to your Cargo.toml:

[dependencies]
tracing-attributes = "0.1.17"

This crate provides the #[instrument] attribute for instrumenting a function with a tracing span. For example:

use tracing_attributes::instrument;

#[instrument]
pub fn my_function(my_arg: usize) {
    // ...
}

Supported Rust Versions

Tracing is built against the latest stable release. The minimum supported version is 1.42. The current Tracing version is not guaranteed to build on Rust versions earlier than the minimum supported version.

Tracing follows the same compiler support policies as the rest of the Tokio project. The current stable Rust compiler and the three most recent minor versions before it will always be supported. For example, if the current stable compiler version is 1.45, the minimum supported version will not be increased past 1.42, three minor versions prior. Increasing the minimum supported compiler version is not considered a semver breaking change as long as doing so complies with this policy.

License

This project is licensed under the MIT license.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Tokio by you, shall be licensed as MIT, without any additional terms or conditions.