[Jump to usage instructions](#usage)
##Lints
-There are 59 lints included in this crate:
+There are 60 lints included in this crate:
name | default | meaning
-------------------------------------------------------------------------------------------------------|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
[min_max](https://github.com/Manishearth/rust-clippy/wiki#min_max) | warn | `min(_, max(_, _))` (or vice versa) with bounds clamping the result to a constant
[modulo_one](https://github.com/Manishearth/rust-clippy/wiki#modulo_one) | warn | taking a number modulo 1, which always returns 0
[mut_mut](https://github.com/Manishearth/rust-clippy/wiki#mut_mut) | allow | usage of double-mut refs, e.g. `&mut &mut ...` (either copy'n'paste error, or shows a fundamental misunderstanding of references)
+[mutex_atomic](https://github.com/Manishearth/rust-clippy/wiki#mutex_atomic) | warn | using a Mutex where an atomic value could be used instead
[needless_bool](https://github.com/Manishearth/rust-clippy/wiki#needless_bool) | warn | if-statements with plain booleans in the then- and else-clause, e.g. `if p { true } else { false }`
[needless_lifetimes](https://github.com/Manishearth/rust-clippy/wiki#needless_lifetimes) | warn | using explicit lifetimes for references in function arguments when elision rules would allow omitting them
[needless_range_loop](https://github.com/Manishearth/rust-clippy/wiki#needless_range_loop) | warn | for-looping over a range of indices where an iterator over items would do
pub mod ranges;
pub mod matches;
pub mod precedence;
+pub mod mutex_atomic;
mod reexport {
pub use syntax::ast::{Name, Ident, NodeId};
reg.register_late_lint_pass(box matches::MatchPass);
reg.register_late_lint_pass(box misc::PatternPass);
reg.register_late_lint_pass(box minmax::MinMaxPass);
+ reg.register_late_lint_pass(box mutex_atomic::MutexAtomic);
reg.register_lint_group("clippy_pedantic", vec![
methods::OPTION_UNWRAP_USED,
misc::REDUNDANT_PATTERN,
misc::TOPLEVEL_REF_ARG,
mut_reference::UNNECESSARY_MUT_PASSED,
+ mutex_atomic::MUTEX_ATOMIC,
needless_bool::NEEDLESS_BOOL,
precedence::PRECEDENCE,
ranges::RANGE_STEP_BY_ZERO,
--- /dev/null
+//! Checks for uses of Mutex where an atomic value could be used
+//!
+//! This lint is **warn** by default
+
+use rustc::lint::{LintPass, LintArray, LateLintPass, LateContext};
+use rustc_front::hir::Expr;
+
+use syntax::ast;
+use rustc::middle::ty;
+use rustc::middle::subst::ParamSpace;
+
+use utils::{span_lint, MUTEX_PATH, match_type};
+
+declare_lint! {
+ pub MUTEX_ATOMIC,
+ Warn,
+ "using a Mutex where an atomic value could be used instead"
+}
+
+impl LintPass for MutexAtomic {
+ fn get_lints(&self) -> LintArray {
+ lint_array!(MUTEX_ATOMIC)
+ }
+}
+pub struct MutexAtomic;
+
+impl LateLintPass for MutexAtomic {
+ fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
+ let ty = cx.tcx.expr_ty(expr);
+ if let &ty::TyStruct(_, subst) = &ty.sty {
+ if match_type(cx, ty, &MUTEX_PATH) {
+ let mutex_param = &subst.types.get(ParamSpace::TypeSpace, 0).sty;
+ if let Some(atomic_name) = get_atomic_name(mutex_param) {
+ let msg = format!("Consider using an {} instead of a \
+ Mutex here.", atomic_name);
+ 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(ast::TyUs) => Some("AtomicUsize"),
+ ty::TyInt(ast::TyIs) => Some("AtomicIsize"),
+ ty::TyRawPtr(_) => Some("AtomicPtr"),
+ _ => None
+ }
+}
pub const STRING_PATH: [&'static str; 3] = ["collections", "string", "String"];
pub const VEC_PATH: [&'static str; 3] = ["collections", "vec", "Vec"];
pub const LL_PATH: [&'static str; 3] = ["collections", "linked_list", "LinkedList"];
+pub const MUTEX_PATH: [&'static str; 4] = ["std", "sync", "mutex", "Mutex"];
/// returns true this expn_info was expanded by any macro
pub fn in_macro(cx: &LateContext, span: Span) -> bool {
--- /dev/null
+#![feature(plugin)]
+
+#![plugin(clippy)]
+#![deny(clippy)]
+
+fn main() {
+ use std::sync::Mutex;
+ Mutex::new(true); //~ERROR Consider using an AtomicBool instead of a Mutex here.
+ Mutex::new(5usize); //~ERROR Consider using an AtomicUsize instead of a Mutex here.
+ Mutex::new(9isize); //~ERROR Consider using an AtomicIsize instead of a Mutex here.
+ let mut x = 4u32;
+ Mutex::new(&x as *const u32); //~ERROR Consider using an AtomicPtr instead of a Mutex here.
+ Mutex::new(&mut x as *mut u32); //~ERROR Consider using an AtomicPtr instead of a Mutex here.
+ Mutex::new(0f32); // there are no float atomics, so this should not lint
+}