-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
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<'tcx>(cx: &LateContext<'tcx>, span: Span, ty: Ty<'tcx>) {
- let ty = walk_ptrs_ty(ty);
+ let ty = ty.peel_refs();
if let Adt(def, substs) = ty.kind() {
if [&paths::HASHMAP, &paths::BTREEMAP, &paths::HASHSET, &paths::BTREESET]
.iter()
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,
}
}