73 lines
2.6 KiB
Rust
73 lines
2.6 KiB
Rust
|
use clippy_utils::diagnostics::span_lint_and_help;
|
||
|
|
use clippy_utils::last_path_segment;
|
||
|
|
use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
|
||
|
|
use if_chain::if_chain;
|
||
|
|
|
||
|
|
use rustc_hir::{Expr, ExprKind};
|
||
|
|
use rustc_lint::LateContext;
|
||
|
|
use rustc_lint::LateLintPass;
|
||
|
|
use rustc_middle::ty;
|
||
|
|
use rustc_session::{declare_lint_pass, declare_tool_lint};
|
||
|
|
use rustc_span::symbol::sym;
|
||
|
|
|
||
|
|
declare_clippy_lint! {
|
||
|
|
/// ### What it does.
|
||
|
|
/// This lint warns when you use `Arc` with a type that does not implement `Send` or `Sync`.
|
||
|
|
///
|
||
|
|
/// ### Why is this bad?
|
||
|
|
/// Wrapping a type in Arc doesn't add thread safety to the underlying data, so data races
|
||
|
|
/// could occur when touching the underlying data.
|
||
|
|
///
|
||
|
|
/// ### Example
|
||
|
|
/// ```rust
|
||
|
|
/// # use std::cell::RefCell;
|
||
|
|
/// # use std::sync::Arc;
|
||
|
|
///
|
||
|
|
/// fn main() {
|
||
|
|
/// // This is safe, as `i32` implements `Send` and `Sync`.
|
||
|
|
/// let a = Arc::new(42);
|
||
|
|
///
|
||
|
|
/// // This is not safe, as `RefCell` does not implement `Sync`.
|
||
|
|
/// let b = Arc::new(RefCell::new(42));
|
||
|
|
/// }
|
||
|
|
/// ```
|
||
|
|
#[clippy::version = "1.72.0"]
|
||
|
|
pub ARC_WITH_NON_SEND_SYNC,
|
||
|
|
correctness,
|
||
|
|
"using `Arc` with a type that does not implement `Send` or `Sync`"
|
||
|
|
}
|
||
|
|
declare_lint_pass!(ArcWithNonSendSync => [ARC_WITH_NON_SEND_SYNC]);
|
||
|
|
|
||
|
|
impl LateLintPass<'_> for ArcWithNonSendSync {
|
||
|
|
fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
|
||
|
|
let ty = cx.typeck_results().expr_ty(expr);
|
||
|
|
if_chain! {
|
||
|
|
if is_type_diagnostic_item(cx, ty, sym::Arc);
|
||
|
|
if let ExprKind::Call(func, [arg]) = expr.kind;
|
||
|
|
if let ExprKind::Path(func_path) = func.kind;
|
||
|
|
if last_path_segment(&func_path).ident.name == sym::new;
|
||
|
|
if let arg_ty = cx.typeck_results().expr_ty(arg);
|
||
|
|
if !matches!(arg_ty.kind(), ty::Param(_));
|
||
|
|
if !cx.tcx
|
||
|
|
.lang_items()
|
||
|
|
.sync_trait()
|
||
|
|
.map_or(false, |id| implements_trait(cx, arg_ty, id, &[])) ||
|
||
|
|
!cx.tcx
|
||
|
|
.get_diagnostic_item(sym::Send)
|
||
|
|
.map_or(false, |id| implements_trait(cx, arg_ty, id, &[]));
|
||
|
|
|
||
|
|
then {
|
||
|
|
span_lint_and_help(
|
||
|
|
cx,
|
||
|
|
ARC_WITH_NON_SEND_SYNC,
|
||
|
|
expr.span,
|
||
|
|
"usage of `Arc<T>` where `T` is not `Send` or `Sync`",
|
||
|
|
None,
|
||
|
|
"consider using `Rc<T>` instead or wrapping `T` in a std::sync type like \
|
||
|
|
`Mutex<T>`",
|
||
|
|
);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|