-use crate::utils::paths;
-use crate::utils::{
- get_trait_def_id, is_allowed, is_automatically_derived, is_copy, match_def_path, match_path, span_lint_and_help,
- span_lint_and_note, span_lint_and_then,
-};
+use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_note, span_lint_and_then};
+use clippy_utils::paths;
+use clippy_utils::ty::{implements_trait, is_copy};
+use clippy_utils::{get_trait_def_id, is_allowed, is_automatically_derived, match_def_path};
use if_chain::if_chain;
use rustc_hir::def_id::DefId;
use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, NestedVisitorMap, Visitor};
use rustc_middle::hir::map::Map;
use rustc_middle::ty::{self, Ty};
use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::source_map::Span;
+use rustc_span::{def_id::LOCAL_CRATE, source_map::Span};
declare_clippy_lint! {
/// **What it does:** Checks for deriving `Hash` but implementing `PartialEq`
..
}) = item.kind
{
- let ty = cx.tcx.type_of(cx.tcx.hir().local_def_id(item.hir_id));
- let is_automatically_derived = is_automatically_derived(&*item.attrs);
+ let ty = cx.tcx.type_of(item.def_id);
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ let is_automatically_derived = is_automatically_derived(attrs);
check_hash_peq(cx, item.span, trait_ref, ty, is_automatically_derived);
check_ord_partial_ord(cx, item.span, trait_ref, ty, is_automatically_derived);
then {
// Look for the PartialEq implementations for `ty`
cx.tcx.for_each_relevant_impl(peq_trait_def_id, ty, |impl_id| {
- let peq_is_automatically_derived = is_automatically_derived(&cx.tcx.get_attrs(impl_id));
+ let peq_is_automatically_derived = is_automatically_derived(cx.tcx.get_attrs(impl_id));
if peq_is_automatically_derived == hash_is_automatically_derived {
return;
then {
// Look for the PartialOrd implementations for `ty`
cx.tcx.for_each_relevant_impl(partial_ord_trait_def_id, ty, |impl_id| {
- let partial_ord_is_automatically_derived = is_automatically_derived(&cx.tcx.get_attrs(impl_id));
+ let partial_ord_is_automatically_derived = is_automatically_derived(cx.tcx.get_attrs(impl_id));
if partial_ord_is_automatically_derived == ord_is_automatically_derived {
return;
/// Implementation of the `EXPL_IMPL_CLONE_ON_COPY` lint.
fn check_copy_clone<'tcx>(cx: &LateContext<'tcx>, item: &Item<'_>, trait_ref: &TraitRef<'_>, ty: Ty<'tcx>) {
- if match_path(&trait_ref.path, &paths::CLONE_TRAIT) {
- if !is_copy(cx, ty) {
+ let clone_id = match cx.tcx.lang_items().clone_trait() {
+ Some(id) if trait_ref.trait_def_id() == Some(id) => id,
+ _ => return,
+ };
+ let copy_id = match cx.tcx.lang_items().copy_trait() {
+ Some(id) => id,
+ None => return,
+ };
+ let (ty_adt, ty_subs) = match *ty.kind() {
+ // Unions can't derive clone.
+ ty::Adt(adt, subs) if !adt.is_union() => (adt, subs),
+ _ => return,
+ };
+ // If the current self type doesn't implement Copy (due to generic constraints), search to see if
+ // there's a Copy impl for any instance of the adt.
+ if !is_copy(cx, ty) {
+ if ty_subs.non_erasable_generics().next().is_some() {
+ let has_copy_impl = cx
+ .tcx
+ .all_local_trait_impls(LOCAL_CRATE)
+ .get(©_id)
+ .map_or(false, |impls| {
+ impls
+ .iter()
+ .any(|&id| matches!(cx.tcx.type_of(id).kind(), ty::Adt(adt, _) if ty_adt.did == adt.did))
+ });
+ if !has_copy_impl {
+ return;
+ }
+ } else {
return;
}
-
- match *ty.kind() {
- ty::Adt(def, _) if def.is_union() => return,
-
- // Some types are not Clone by default but could be cloned “by hand” if necessary
- ty::Adt(def, substs) => {
- for variant in &def.variants {
- for field in &variant.fields {
- if let ty::FnDef(..) = field.ty(cx.tcx, substs).kind() {
- return;
- }
- }
- for subst in substs {
- if let ty::subst::GenericArgKind::Type(subst) = subst.unpack() {
- if let ty::Param(_) = subst.kind() {
- return;
- }
- }
- }
- }
- },
- _ => (),
- }
-
- span_lint_and_note(
- cx,
- EXPL_IMPL_CLONE_ON_COPY,
- item.span,
- "you are implementing `Clone` explicitly on a `Copy` type",
- Some(item.span),
- "consider deriving `Clone` or removing `Copy`",
- );
}
+ // Derive constrains all generic types to requiring Clone. Check if any type is not constrained for
+ // this impl.
+ if ty_subs.types().any(|ty| !implements_trait(cx, ty, clone_id, &[])) {
+ return;
+ }
+
+ span_lint_and_note(
+ cx,
+ EXPL_IMPL_CLONE_ON_COPY,
+ item.span,
+ "you are implementing `Clone` explicitly on a `Copy` type",
+ Some(item.span),
+ "consider deriving `Clone` or removing `Copy`",
+ );
}
/// Implementation of the `UNSAFE_DERIVE_DESERIALIZE` lint.