1 files changed, 24 insertions, 4 deletions
diff --git a/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs b/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
index 3df40942e..4a845ca63 100644
--- a/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
+++ b/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
@@ -15,7 +15,8 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit::{walk_expr, Visitor};
 use rustc_hir::{def_id::DefId, Block, Expr, ExprKind, QPath, UnOp};
 use rustc_lint::LateContext;
-use rustc_middle::ty::{self, PredicateKind};
+use rustc_middle::ty;
+use rustc_middle::ty::adjustment::Adjust;
 use rustc_span::{sym, Symbol};
 use std::cmp;
 use std::ops;
@@ -73,7 +74,7 @@ fn fn_eagerness(cx: &LateContext<'_>, fn_id: DefId, name: Symbol, have_one_arg:
             .flat_map(|v| v.fields.iter())
             .any(|x| matches!(cx.tcx.type_of(x.did).subst_identity().peel_refs().kind(), ty::Param(_)))
             && all_predicates_of(cx.tcx, fn_id).all(|(pred, _)| match pred.kind().skip_binder() {
-                PredicateKind::Clause(ty::Clause::Trait(pred)) => cx.tcx.trait_def(pred.trait_ref.def_id).is_marker,
+                ty::ClauseKind::Trait(pred) => cx.tcx.trait_def(pred.trait_ref.def_id).is_marker,
                 _ => true,
             })
             && subs.types().all(|x| matches!(x.peel_refs().kind(), ty::Param(_)))
@@ -114,6 +115,20 @@ fn expr_eagerness<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> EagernessS
             if self.eagerness == ForceNoChange {
                 return;
             }
+
+            // Autoderef through a user-defined `Deref` impl can have side-effects,
+            // so don't suggest changing it.
+            if self
+                .cx
+                .typeck_results()
+                .expr_adjustments(e)
+                .iter()
+                .any(|adj| matches!(adj.kind, Adjust::Deref(Some(_))))
+            {
+                self.eagerness |= NoChange;
+                return;
+            }
+
             match e.kind {
                 ExprKind::Call(
                     &Expr {
@@ -173,11 +188,15 @@ fn expr_eagerness<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> EagernessS
                         self.eagerness = Lazy;
                     }
                 },
-
+                // Custom `Deref` impl might have side effects
+                ExprKind::Unary(UnOp::Deref, e)
+                    if self.cx.typeck_results().expr_ty(e).builtin_deref(true).is_none() =>
+                {
+                    self.eagerness |= NoChange;
+                },
                 // Dereferences should be cheap, but dereferencing a raw pointer earlier may not be safe.
                 ExprKind::Unary(UnOp::Deref, e) if !self.cx.typeck_results().expr_ty(e).is_unsafe_ptr() => (),
                 ExprKind::Unary(UnOp::Deref, _) => self.eagerness |= NoChange,
-
                 ExprKind::Unary(_, e)
                     if matches!(
                         self.cx.typeck_results().expr_ty(e).kind(),
@@ -191,6 +210,7 @@ fn expr_eagerness<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> EagernessS
                 ExprKind::Break(..)
                 | ExprKind::Continue(_)
                 | ExprKind::Ret(_)
+                | ExprKind::Become(_)
                 | ExprKind::InlineAsm(_)
                 | ExprKind::Yield(..)
                 | ExprKind::Err(_) => {