rust-clippy/clippy_lints/src/dbg_macro.rs
2022-06-05 16:03:18 -04:00

101 lines
3.2 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};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_tool_lint, impl_lint_pass};
use rustc_span::sym;
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.
///
/// ### 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 suggestion = match expr.peel_drop_temps().kind {
// dbg!()
ExprKind::Block(_, _) => String::new(),
// dbg!(1)
ExprKind::Match(val, ..) => {
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,
);
format!("({snippet})")
},
_ => return,
};
span_lint_and_sugg(
cx,
DBG_MACRO,
macro_call.span,
"`dbg!` macro is intended as a debugging tool",
"ensure to avoid having uses of it in version control",
suggestion,
applicability,
);
}
}
}