-use crate::utils::{match_def_path, paths, span_lint, trait_ref_of_method, walk_ptrs_ty};
+use crate::utils::{match_def_path, paths, span_lint, trait_ref_of_method};
use rustc_hir as hir;
use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::TypeFoldable;
use rustc_middle::ty::{Adt, Array, RawPtr, Ref, Slice, Tuple, Ty, TypeAndMut};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::Span;
/// `BtreeSet` rely on either the hash or the order of keys be unchanging,
/// so having types with interior mutability is a bad idea.
///
- /// **Known problems:** We don't currently account for `Rc` or `Arc`, so
- /// this may yield false positives.
+ /// **Known problems:** It's correct to use a struct, that contains interior mutability
+ /// as a key, when its `Hash` implementation doesn't access any of the interior mutable types.
+ /// However, this lint is unable to recognize this, so it causes a false positive in theses cases.
+ /// The `bytes` crate is a great example of this.
///
/// **Example:**
/// ```rust
declare_lint_pass!(MutableKeyType => [ MUTABLE_KEY_TYPE ]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MutableKeyType {
- fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item<'tcx>) {
+impl<'tcx> LateLintPass<'tcx> for MutableKeyType {
+ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
if let hir::ItemKind::Fn(ref sig, ..) = item.kind {
check_sig(cx, item.hir_id, &sig.decl);
}
}
- fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::ImplItem<'tcx>) {
+ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::ImplItem<'tcx>) {
if let hir::ImplItemKind::Fn(ref sig, ..) = item.kind {
if trait_ref_of_method(cx, item.hir_id).is_none() {
check_sig(cx, item.hir_id, &sig.decl);
}
}
- fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::TraitItem<'tcx>) {
+ fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'tcx>) {
if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
check_sig(cx, item.hir_id, &sig.decl);
}
}
- fn check_local(&mut self, cx: &LateContext<'_, '_>, local: &hir::Local<'_>) {
+ fn check_local(&mut self, cx: &LateContext<'_>, local: &hir::Local<'_>) {
if let hir::PatKind::Wild = local.pat.kind {
return;
}
- check_ty(cx, local.span, cx.tables.pat_ty(&*local.pat));
+ check_ty(cx, local.span, cx.typeck_results().pat_ty(&*local.pat));
}
}
-fn check_sig<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, item_hir_id: hir::HirId, decl: &hir::FnDecl<'_>) {
+fn check_sig<'tcx>(cx: &LateContext<'tcx>, item_hir_id: hir::HirId, decl: &hir::FnDecl<'_>) {
let fn_def_id = cx.tcx.hir().local_def_id(item_hir_id);
let fn_sig = cx.tcx.fn_sig(fn_def_id);
for (hir_ty, ty) in decl.inputs.iter().zip(fn_sig.inputs().skip_binder().iter()) {
check_ty(cx, hir_ty.span, ty);
}
- check_ty(
- cx,
- decl.output.span(),
- cx.tcx.erase_late_bound_regions(&fn_sig.output()),
- );
+ check_ty(cx, decl.output.span(), cx.tcx.erase_late_bound_regions(fn_sig.output()));
}
// We want to lint 1. sets or maps with 2. not immutable key types and 3. no unerased
// generics (because the compiler cannot ensure immutability for unknown types).
-fn check_ty<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, span: Span, ty: Ty<'tcx>) {
- let ty = walk_ptrs_ty(ty);
- if let Adt(def, substs) = ty.kind {
+fn check_ty<'tcx>(cx: &LateContext<'tcx>, span: Span, ty: Ty<'tcx>) {
+ let ty = ty.peel_refs();
+ if let Adt(def, substs) = ty.kind() {
if [&paths::HASHMAP, &paths::BTREEMAP, &paths::HASHSET, &paths::BTREESET]
.iter()
.any(|path| match_def_path(cx, def.did, &**path))
}
}
-fn is_mutable_type<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>, span: Span) -> bool {
- match ty.kind {
+fn is_mutable_type<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, span: Span) -> bool {
+ match *ty.kind() {
RawPtr(TypeAndMut { ty: inner_ty, mutbl }) | Ref(_, inner_ty, mutbl) => {
mutbl == hir::Mutability::Mut || is_mutable_type(cx, inner_ty, span)
},
size.try_eval_usize(cx.tcx, cx.param_env).map_or(true, |u| u != 0) && is_mutable_type(cx, inner_ty, span)
},
Tuple(..) => ty.tuple_fields().any(|ty| is_mutable_type(cx, ty, span)),
- Adt(..) => cx.tcx.layout_of(cx.param_env.and(ty)).is_ok() && !ty.is_freeze(cx.tcx.at(span), cx.param_env),
+ Adt(..) => {
+ cx.tcx.layout_of(cx.param_env.and(ty)).is_ok()
+ && !ty.has_escaping_bound_vars()
+ && !ty.is_freeze(cx.tcx.at(span), cx.param_env)
+ },
_ => false,
}
}