//!
//! This lint is **warn** by default
-use rustc::lint::{LintPass, LintArray, LateLintPass, LateContext};
-use rustc::ty;
+use crate::utils::{match_type, paths, span_lint};
+use rustc::declare_lint_pass;
use rustc::hir::Expr;
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::ty::{self, Ty};
+use rustc_session::declare_tool_lint;
use syntax::ast;
-use utils::{match_type, paths, span_lint};
-/// **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
-/// reference sequential is shooting flies with cannons.
-/// `std::atomic::AtomicBool` and `std::atomic::AtomicPtr` are leaner and
-/// faster.
-///
-/// **Known problems:** This lint cannot detect if the mutex is actually used
-/// for waiting before a critical section.
-///
-/// **Example:**
-/// ```rust
-/// let x = Mutex::new(&y);
-/// ```
-declare_lint! {
+declare_clippy_lint! {
+ /// **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
+ /// 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
+ /// for waiting before a critical section.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # use std::sync::Mutex;
+ /// # let y = 1;
+ /// let x = Mutex::new(&y);
+ /// ```
pub MUTEX_ATOMIC,
- Warn,
+ perf,
"using a mutex where an atomic value could be used instead"
}
-/// **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 sequential is
-/// shooting flies with cannons. `std::atomic::usize` is leaner and faster.
-///
-/// **Known problems:** This lint cannot detect if the mutex is actually used
-/// for waiting before a critical section.
-///
-/// **Example:**
-/// ```rust
-/// let x = Mutex::new(0usize);
-/// ```
-declare_lint! {
+declare_clippy_lint! {
+ /// **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
+ /// 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
+ /// for waiting before a critical section.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # use std::sync::Mutex;
+ /// let x = Mutex::new(0usize);
+ /// ```
pub MUTEX_INTEGER,
- Allow,
+ nursery,
"using a mutex for an integer type"
}
-impl LintPass for MutexAtomic {
- fn get_lints(&self) -> LintArray {
- lint_array!(MUTEX_ATOMIC, MUTEX_INTEGER)
- }
-}
-
-pub struct MutexAtomic;
+declare_lint_pass!(Mutex => [MUTEX_ATOMIC, MUTEX_INTEGER]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MutexAtomic {
+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::TyAdt(_, subst) = ty.sty {
+ if let ty::Adt(_, subst) = ty.kind {
if match_type(cx, ty, &paths::MUTEX) {
- let mutex_param = &subst.type_at(0).sty;
+ 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<()>.",
- atomic_name);
- match *mutex_param {
- ty::TyUint(t) if t != ast::UintTy::Us => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
- ty::TyInt(t) if t != ast::IntTy::Is => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
+ 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<()>.",
+ 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),
_ => span_lint(cx, MUTEX_ATOMIC, expr.span, &msg),
};
}
}
}
-fn get_atomic_name(ty: &ty::TypeVariants) -> Option<(&'static str)> {
- match *ty {
- ty::TyBool => Some("AtomicBool"),
- ty::TyUint(_) => Some("AtomicUsize"),
- ty::TyInt(_) => Some("AtomicIsize"),
- ty::TyRawPtr(_) => Some("AtomicPtr"),
+fn get_atomic_name(ty: Ty<'_>) -> Option<&'static str> {
+ match ty.kind {
+ ty::Bool => Some("AtomicBool"),
+ ty::Uint(_) => Some("AtomicUsize"),
+ ty::Int(_) => Some("AtomicIsize"),
+ ty::RawPtr(_) => Some("AtomicPtr"),
_ => None,
}
}