1 use clippy_utils::diagnostics::span_lint_and_sugg;
2 use clippy_utils::is_no_std_crate;
3 use clippy_utils::source::snippet_opt;
4 use clippy_utils::{meets_msrv, msrvs};
5 use if_chain::if_chain;
6 use rustc_errors::Applicability;
7 use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability, TyKind};
8 use rustc_lint::{LateContext, LateLintPass};
9 use rustc_semver::RustcVersion;
10 use rustc_session::{declare_tool_lint, impl_lint_pass};
12 declare_clippy_lint! {
14 /// Checks for the usage of `&expr as *const T` or
15 /// `&mut expr as *mut T`, and suggest using `ptr::addr_of` or
16 /// `ptr::addr_of_mut` instead.
18 /// ### Why is this bad?
19 /// This would improve readability and avoid creating a reference
20 /// that points to an uninitialized value or unaligned place.
21 /// Read the `ptr::addr_of` docs for more information.
26 /// let p = &val as *const i32;
28 /// let mut val_mut = 1;
29 /// let p_mut = &mut val_mut as *mut i32;
34 /// let p = std::ptr::addr_of!(val);
36 /// let mut val_mut = 1;
37 /// let p_mut = std::ptr::addr_of_mut!(val_mut);
39 #[clippy::version = "1.60.0"]
42 "borrowing just to cast to a raw pointer"
45 impl_lint_pass!(BorrowAsPtr => [BORROW_AS_PTR]);
47 pub struct BorrowAsPtr {
48 msrv: Option<RustcVersion>,
53 pub fn new(msrv: Option<RustcVersion>) -> Self {
58 impl<'tcx> LateLintPass<'tcx> for BorrowAsPtr {
59 fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
60 if !meets_msrv(self.msrv, msrvs::BORROW_AS_PTR) {
64 if expr.span.from_expansion() {
69 if let ExprKind::Cast(left_expr, ty) = &expr.kind;
70 if let TyKind::Ptr(_) = ty.kind;
71 if let ExprKind::AddrOf(BorrowKind::Ref, mutability, e) = &left_expr.kind;
74 let core_or_std = if is_no_std_crate(cx) { "core" } else { "std" };
75 let macro_name = match mutability {
76 Mutability::Not => "addr_of",
77 Mutability::Mut => "addr_of_mut",
84 "borrow as raw pointer",
90 snippet_opt(cx, e.span).unwrap()
92 Applicability::MachineApplicable,
98 extract_msrv_attr!(LateContext);