//!
//! This lint is **warn** by default
-use crate::utils::{match_type, paths, span_lint};
-use rustc::declare_lint_pass;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::ty::{self, Ty};
+use crate::utils::{is_type_diagnostic_item, span_lint};
+use rustc_ast::ast;
use rustc_hir::Expr;
-use rustc_session::declare_tool_lint;
-use syntax::ast;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
/// **What it does:** Checks for usages of `Mutex<X>` where an atomic will do.
///
/// **Example:**
/// ```rust
+ /// # let y = true;
+ ///
+ /// // Bad
/// # use std::sync::Mutex;
- /// # let y = 1;
/// let x = Mutex::new(&y);
+ ///
+ /// // Good
+ /// # use std::sync::atomic::AtomicBool;
+ /// let x = AtomicBool::new(y);
/// ```
pub MUTEX_ATOMIC,
perf,
/// ```rust
/// # use std::sync::Mutex;
/// let x = Mutex::new(0usize);
+ ///
+ /// // Good
+ /// # use std::sync::atomic::AtomicUsize;
+ /// let x = AtomicUsize::new(0usize);
/// ```
pub MUTEX_INTEGER,
nursery,
declare_lint_pass!(Mutex => [MUTEX_ATOMIC, MUTEX_INTEGER]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Mutex {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
- let ty = cx.tables.expr_ty(expr);
- if let ty::Adt(_, subst) = ty.kind {
- if match_type(cx, ty, &paths::MUTEX) {
+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)) {
let mutex_param = subst.type_at(0);
if let Some(atomic_name) = get_atomic_name(mutex_param) {
let msg = format!(
- "Consider using an {} instead of a Mutex here. If you just want the locking \
- behaviour and not the internal type, consider using Mutex<()>.",
+ "consider using an `{}` instead of a `Mutex` here; if you just want the locking \
+ behavior and not the internal type, consider using `Mutex<()>`",
atomic_name
);
- match mutex_param.kind {
+ 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),
_ => 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"),