//!
//! This lint is **warn** by default
-use crate::utils::{is_type_diagnostic_item, span_lint};
-use rustc_ast::ast;
+use clippy_utils::diagnostics::span_lint;
+use clippy_utils::ty::is_type_diagnostic_item;
use rustc_hir::Expr;
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty::{self, Ty};
use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
declare_clippy_lint! {
- /// **What it does:** Checks for usages of `Mutex<X>` where an atomic will do.
+ /// ### What it does
+ /// Checks for usages of `Mutex<X>` where an atomic will do.
///
- /// **Why is this bad?** Using a mutex just to make access to a plain bool or
+ /// ### Why is this bad?
+ /// Using a mutex just to make access to a plain bool or
/// reference sequential is shooting flies with cannons.
/// `std::sync::atomic::AtomicBool` and `std::sync::atomic::AtomicPtr` are leaner and
/// faster.
///
- /// **Known problems:** This lint cannot detect if the mutex is actually used
+ /// ### Known problems
+ /// This lint cannot detect if the mutex is actually used
/// for waiting before a critical section.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let y = true;
///
/// # use std::sync::atomic::AtomicBool;
/// let x = AtomicBool::new(y);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub MUTEX_ATOMIC,
- perf,
+ nursery,
"using a mutex where an atomic value could be used instead"
}
declare_clippy_lint! {
- /// **What it does:** Checks for usages of `Mutex<X>` where `X` is an integral
+ /// ### What it does
+ /// Checks for usages of `Mutex<X>` where `X` is an integral
/// type.
///
- /// **Why is this bad?** Using a mutex just to make access to a plain integer
+ /// ### Why is this bad?
+ /// Using a mutex just to make access to a plain integer
/// sequential is
/// shooting flies with cannons. `std::sync::atomic::AtomicUsize` is leaner and faster.
///
- /// **Known problems:** This lint cannot detect if the mutex is actually used
+ /// ### Known problems
+ /// This lint cannot detect if the mutex is actually used
/// for waiting before a critical section.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # use std::sync::Mutex;
/// let x = Mutex::new(0usize);
/// # use std::sync::atomic::AtomicUsize;
/// let x = AtomicUsize::new(0usize);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub MUTEX_INTEGER,
nursery,
"using a mutex for an integer type"
impl<'tcx> LateLintPass<'tcx> for Mutex {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
let ty = cx.typeck_results().expr_ty(expr);
- if let ty::Adt(_, subst) = ty.kind {
- if is_type_diagnostic_item(cx, ty, sym!(mutex_type)) {
+ if let ty::Adt(_, subst) = ty.kind() {
+ if is_type_diagnostic_item(cx, ty, sym::Mutex) {
let mutex_param = subst.type_at(0);
if let Some(atomic_name) = get_atomic_name(mutex_param) {
let msg = format!(
behavior and not the internal type, consider using `Mutex<()>`",
atomic_name
);
- match mutex_param.kind {
- ty::Uint(t) if t != ast::UintTy::Usize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
- ty::Int(t) if t != ast::IntTy::Isize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
+ match *mutex_param.kind() {
+ ty::Uint(t) if t != ty::UintTy::Usize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
+ ty::Int(t) if t != ty::IntTy::Isize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
_ => span_lint(cx, MUTEX_ATOMIC, expr.span, &msg),
};
}
}
fn get_atomic_name(ty: Ty<'_>) -> Option<&'static str> {
- match ty.kind {
+ match ty.kind() {
ty::Bool => Some("AtomicBool"),
ty::Uint(_) => Some("AtomicUsize"),
ty::Int(_) => Some("AtomicIsize"),