rust/clippy_lints/src/dbg_macro.rs

76 lines
2.5 KiB
Rust

use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
use clippy_utils::source::snippet_opt;
use rustc_ast::ast;
use rustc_ast::tokenstream::TokenStream;
use rustc_errors::Applicability;
use rustc_lint::{EarlyContext, EarlyLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::Span;
declare_clippy_lint! {
/// ### What it does
/// Checks for usage of dbg!() macro.
///
/// ### Why is this bad?
/// `dbg!` macro is intended as a debugging tool. It
/// should not be in version control.
///
/// ### Known problems
/// * The lint level is unaffected by crate attributes. The level can still
/// be set for functions, modules and other items. To change the level for
/// the entire crate, please use command line flags. More information and a
/// configuration example can be found in [clippy#6610].
///
/// [clippy#6610]: https://github.com/rust-lang/rust-clippy/issues/6610#issuecomment-977120558
///
/// ### Example
/// ```rust,ignore
/// // Bad
/// dbg!(true)
///
/// // Good
/// true
/// ```
#[clippy::version = "1.34.0"]
pub DBG_MACRO,
restriction,
"`dbg!` macro is intended as a debugging tool"
}
declare_lint_pass!(DbgMacro => [DBG_MACRO]);
impl EarlyLintPass for DbgMacro {
fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &ast::MacCall) {
if mac.path == sym!(dbg) {
if let Some(sugg) = tts_span(mac.args.inner_tokens()).and_then(|span| snippet_opt(cx, span)) {
span_lint_and_sugg(
cx,
DBG_MACRO,
mac.span(),
"`dbg!` macro is intended as a debugging tool",
"ensure to avoid having uses of it in version control",
sugg,
Applicability::MaybeIncorrect,
);
} else {
span_lint_and_help(
cx,
DBG_MACRO,
mac.span(),
"`dbg!` macro is intended as a debugging tool",
None,
"ensure to avoid having uses of it in version control",
);
}
}
}
}
// Get span enclosing entire the token stream.
fn tts_span(tts: TokenStream) -> Option<Span> {
let mut cursor = tts.into_trees();
let first = cursor.next()?.span();
let span = cursor.last().map_or(first, |tree| first.to(tree.span()));
Some(span)
}