rust/clippy_lints/src/dbg_macro.rs

116 lines
4.0 KiB
Rust

use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::macros::root_macro_call_first_node;
use clippy_utils::source::snippet_with_applicability;
use clippy_utils::{is_in_cfg_test, is_in_test_function};
use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind, Node};
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_session::impl_lint_pass;
use rustc_span::sym;
declare_clippy_lint! {
/// ### What it does
/// Checks for usage of the [`dbg!`](https://doc.rust-lang.org/std/macro.dbg.html) macro.
///
/// ### Why is this bad?
/// The `dbg!` macro is intended as a debugging tool. It should not be present in released
/// software or committed to a version control system.
///
/// ### Example
/// ```rust,ignore
/// dbg!(true)
/// ```
///
/// Use instead:
/// ```rust,ignore
/// true
/// ```
#[clippy::version = "1.34.0"]
pub DBG_MACRO,
restriction,
"`dbg!` macro is intended as a debugging tool"
}
#[derive(Copy, Clone)]
pub struct DbgMacro {
allow_dbg_in_tests: bool,
}
impl_lint_pass!(DbgMacro => [DBG_MACRO]);
impl DbgMacro {
pub fn new(allow_dbg_in_tests: bool) -> Self {
DbgMacro { allow_dbg_in_tests }
}
}
impl LateLintPass<'_> for DbgMacro {
fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
let Some(macro_call) = root_macro_call_first_node(cx, expr) else {
return;
};
if cx.tcx.is_diagnostic_item(sym::dbg_macro, macro_call.def_id) {
// allows `dbg!` in test code if allow-dbg-in-test is set to true in clippy.toml
if self.allow_dbg_in_tests
&& (is_in_test_function(cx.tcx, expr.hir_id) || is_in_cfg_test(cx.tcx, expr.hir_id))
{
return;
}
let mut applicability = Applicability::MachineApplicable;
let (sugg_span, suggestion) = match expr.peel_drop_temps().kind {
// dbg!()
ExprKind::Block(..) => {
// If the `dbg!` macro is a "free" statement and not contained within other expressions,
// remove the whole statement.
if let Some(Node::Stmt(_)) = cx.tcx.hir().find_parent(expr.hir_id)
&& let Some(semi_span) = cx.sess().source_map().mac_call_stmt_semi_span(macro_call.span)
{
(macro_call.span.to(semi_span), String::new())
} else {
(macro_call.span, String::from("()"))
}
},
// dbg!(1)
ExprKind::Match(val, ..) => (
macro_call.span,
snippet_with_applicability(cx, val.span.source_callsite(), "..", &mut applicability).to_string(),
),
// dbg!(2, 3)
ExprKind::Tup(
[
Expr {
kind: ExprKind::Match(first, ..),
..
},
..,
Expr {
kind: ExprKind::Match(last, ..),
..
},
],
) => {
let snippet = snippet_with_applicability(
cx,
first.span.source_callsite().to(last.span.source_callsite()),
"..",
&mut applicability,
);
(macro_call.span, format!("({snippet})"))
},
_ => return,
};
span_lint_and_sugg(
cx,
DBG_MACRO,
sugg_span,
"the `dbg!` macro is intended as a debugging tool",
"remove the invocation before committing it to a version control system",
suggestion,
applicability,
);
}
}
}