rust/clippy_lints/src/functions/impl_trait_in_params.rs
2025-01-19 15:34:07 +01:00

85 lines
3.2 KiB
Rust

use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::is_in_test;
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_hir::intravisit::FnKind;
use rustc_hir::{Body, GenericParam, Generics, HirId, ImplItem, ImplItemKind, TraitItem, TraitItemKind};
use rustc_lint::LateContext;
use super::IMPL_TRAIT_IN_PARAMS;
fn report(cx: &LateContext<'_>, param: &GenericParam<'_>, generics: &Generics<'_>) {
// No generics with nested generics, and no generics like FnMut(x)
span_lint_and_then(
cx,
IMPL_TRAIT_IN_PARAMS,
param.span,
"`impl Trait` used as a function parameter",
|diag| {
if let Some(gen_span) = generics.span_for_param_suggestion() {
// If there's already a generic param with the same bound, do not lint **this** suggestion.
diag.span_suggestion_verbose(
gen_span,
"add a type parameter",
format!(", {{ /* Generic name */ }}: {}", &param.name.ident().as_str()[5..]),
Applicability::HasPlaceholders,
);
} else {
diag.span_suggestion_verbose(
generics.span,
"add a type parameter",
format!("<{{ /* Generic name */ }}: {}>", &param.name.ident().as_str()[5..]),
Applicability::HasPlaceholders,
);
}
},
);
}
pub(super) fn check_fn<'tcx>(cx: &LateContext<'_>, kind: &'tcx FnKind<'_>, body: &'tcx Body<'_>, hir_id: HirId) {
if let FnKind::ItemFn(_, generics, _) = kind
&& cx.tcx.visibility(cx.tcx.hir().body_owner_def_id(body.id())).is_public()
&& !is_in_test(cx.tcx, hir_id)
{
for param in generics.params {
if param.is_impl_trait() {
report(cx, param, generics);
}
}
}
}
pub(super) fn check_impl_item(cx: &LateContext<'_>, impl_item: &ImplItem<'_>) {
if let ImplItemKind::Fn(_, body_id) = impl_item.kind
&& let hir::Node::Item(item) = cx.tcx.parent_hir_node(impl_item.hir_id())
&& let hir::ItemKind::Impl(impl_) = item.kind
&& let hir::Impl { of_trait, .. } = *impl_
&& of_trait.is_none()
&& let body = cx.tcx.hir().body(body_id)
&& cx.tcx.visibility(cx.tcx.hir().body_owner_def_id(body.id())).is_public()
&& !is_in_test(cx.tcx, impl_item.hir_id())
{
for param in impl_item.generics.params {
if param.is_impl_trait() {
report(cx, param, impl_item.generics);
}
}
}
}
pub(super) fn check_trait_item(cx: &LateContext<'_>, trait_item: &TraitItem<'_>, avoid_breaking_exported_api: bool) {
if !avoid_breaking_exported_api
&& let TraitItemKind::Fn(_, _) = trait_item.kind
&& let hir::Node::Item(item) = cx.tcx.parent_hir_node(trait_item.hir_id())
// ^^ (Will always be a trait)
&& !item.vis_span.is_empty() // Is public
&& !is_in_test(cx.tcx, trait_item.hir_id())
{
for param in trait_item.generics.params {
if param.is_impl_trait() {
report(cx, param, trait_item.generics);
}
}
}
}