1 //! checks for `#[inline]` on trait methods without bodies
3 use clippy_utils::diagnostics::span_lint_and_then;
4 use clippy_utils::sugg::DiagnosticExt;
5 use rustc_ast::ast::Attribute;
6 use rustc_errors::Applicability;
7 use rustc_hir::{TraitFn, TraitItem, TraitItemKind};
8 use rustc_lint::{LateContext, LateLintPass};
9 use rustc_session::{declare_lint_pass, declare_tool_lint};
10 use rustc_span::{sym, Symbol};
12 declare_clippy_lint! {
14 /// Checks for `#[inline]` on trait methods without bodies
16 /// ### Why is this bad?
17 /// Only implementations of trait methods may be inlined.
18 /// The inline attribute is ignored for trait methods without bodies.
24 /// fn name(&self) -> &'static str;
27 #[clippy::version = "pre 1.29.0"]
28 pub INLINE_FN_WITHOUT_BODY,
30 "use of `#[inline]` on trait methods without bodies"
33 declare_lint_pass!(InlineFnWithoutBody => [INLINE_FN_WITHOUT_BODY]);
35 impl<'tcx> LateLintPass<'tcx> for InlineFnWithoutBody {
36 fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'_>) {
37 if let TraitItemKind::Fn(_, TraitFn::Required(_)) = item.kind {
38 let attrs = cx.tcx.hir().attrs(item.hir_id());
39 check_attrs(cx, item.ident.name, attrs);
44 fn check_attrs(cx: &LateContext<'_>, name: Symbol, attrs: &[Attribute]) {
46 if !attr.has_name(sym::inline) {
52 INLINE_FN_WITHOUT_BODY,
54 &format!("use of `#[inline]` on trait method `{}` which has no body", name),
56 diag.suggest_remove_item(cx, attr.span, "remove", Applicability::MachineApplicable);