Drop uplifted clippy::drop_ref

9 files changed, 58 insertions, 318 deletions

diff --git a/src/tools/clippy/clippy_lints/src/declared_lints.rs b/src/tools/clippy/clippy_lints/src/declared_lints.rs
index 79d0f6f3607..07978d971db 100644
--- a/src/tools/clippy/clippy_lints/src/declared_lints.rs
+++ b/src/tools/clippy/clippy_lints/src/declared_lints.rs
@@ -134,7 +134,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::double_parens::DOUBLE_PARENS_INFO,
     crate::drop_forget_ref::DROP_COPY_INFO,
     crate::drop_forget_ref::DROP_NON_DROP_INFO,
-    crate::drop_forget_ref::DROP_REF_INFO,
     crate::drop_forget_ref::FORGET_COPY_INFO,
     crate::drop_forget_ref::FORGET_NON_DROP_INFO,
     crate::drop_forget_ref::FORGET_REF_INFO,
diff --git a/src/tools/clippy/clippy_lints/src/drop_forget_ref.rs b/src/tools/clippy/clippy_lints/src/drop_forget_ref.rs
index 11e1bcdf12d..55d7c3247cd 100644
--- a/src/tools/clippy/clippy_lints/src/drop_forget_ref.rs
+++ b/src/tools/clippy/clippy_lints/src/drop_forget_ref.rs
@@ -9,30 +9,6 @@ use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for calls to `std::mem::drop` with a reference
-    /// instead of an owned value.
-    ///
-    /// ### Why is this bad?
-    /// Calling `drop` on a reference will only drop the
-    /// reference itself, which is a no-op. It will not call the `drop` method (from
-    /// the `Drop` trait implementation) on the underlying referenced value, which
-    /// is likely what was intended.
-    ///
-    /// ### Example
-    /// ```ignore
-    /// let mut lock_guard = mutex.lock();
-    /// std::mem::drop(&lock_guard) // Should have been drop(lock_guard), mutex
-    /// // still locked
-    /// operation_that_requires_mutex_to_be_unlocked();
-    /// ```
-    #[clippy::version = "pre 1.29.0"]
-    pub DROP_REF,
-    correctness,
-    "calls to `std::mem::drop` with a reference instead of an owned value"
-}
-
-declare_clippy_lint! {
-    /// ### What it does
     /// Checks for calls to `std::mem::forget` with a reference
     /// instead of an owned value.
     ///
@@ -172,8 +148,6 @@ declare_clippy_lint! {
     "use of safe `std::mem::drop` function to drop a std::mem::ManuallyDrop, which will not drop the inner value"
 }
 
-const DROP_REF_SUMMARY: &str = "calls to `std::mem::drop` with a reference instead of an owned value. \
-                                Dropping a reference does nothing";
 const FORGET_REF_SUMMARY: &str = "calls to `std::mem::forget` with a reference instead of an owned value. \
                                   Forgetting a reference does nothing";
 const DROP_COPY_SUMMARY: &str = "calls to `std::mem::drop` with a value that implements `Copy`. \
@@ -186,7 +160,6 @@ const FORGET_NON_DROP_SUMMARY: &str = "call to `std::mem::forget` with a value t
                                    Forgetting such a type is the same as dropping it";
 
 declare_lint_pass!(DropForgetRef => [
-    DROP_REF,
     FORGET_REF,
     DROP_COPY,
     FORGET_COPY,
@@ -206,7 +179,8 @@ impl<'tcx> LateLintPass<'tcx> for DropForgetRef {
             let is_copy = is_copy(cx, arg_ty);
             let drop_is_single_call_in_arm = is_single_call_in_arm(cx, arg, expr);
             let (lint, msg) = match fn_name {
-                sym::mem_drop if arg_ty.is_ref() && !drop_is_single_call_in_arm => (DROP_REF, DROP_REF_SUMMARY),
+                // early return for uplifted lints: drop_ref
+                sym::mem_drop if arg_ty.is_ref() && !drop_is_single_call_in_arm => return,
                 sym::mem_forget if arg_ty.is_ref() => (FORGET_REF, FORGET_REF_SUMMARY),
                 sym::mem_drop if is_copy && !drop_is_single_call_in_arm => (DROP_COPY, DROP_COPY_SUMMARY),
                 sym::mem_forget if is_copy => (FORGET_COPY, FORGET_COPY_SUMMARY),
diff --git a/src/tools/clippy/clippy_lints/src/renamed_lints.rs b/src/tools/clippy/clippy_lints/src/renamed_lints.rs
index 5e81a01a461..c55eaa809cf 100644
--- a/src/tools/clippy/clippy_lints/src/renamed_lints.rs
+++ b/src/tools/clippy/clippy_lints/src/renamed_lints.rs
@@ -32,6 +32,7 @@ pub static RENAMED_LINTS: &[(&str, &str)] = &[
     ("clippy::zero_width_space", "clippy::invisible_characters"),
     ("clippy::clone_double_ref", "suspicious_double_ref_op"),
     ("clippy::drop_bounds", "drop_bounds"),
+    ("clippy::drop_ref", "drop_ref"),
     ("clippy::for_loop_over_option", "for_loops_over_fallibles"),
     ("clippy::for_loop_over_result", "for_loops_over_fallibles"),
     ("clippy::for_loops_over_fallibles", "for_loops_over_fallibles"),
diff --git a/src/tools/clippy/tests/ui/drop_forget_copy.rs b/src/tools/clippy/tests/ui/drop_forget_copy.rs
index a7276dd59f4..04293eb16bb 100644
--- a/src/tools/clippy/tests/ui/drop_forget_copy.rs
+++ b/src/tools/clippy/tests/ui/drop_forget_copy.rs
@@ -1,5 +1,5 @@
 #![warn(clippy::drop_copy, clippy::forget_copy)]
-#![allow(clippy::toplevel_ref_arg, clippy::drop_ref, clippy::forget_ref, unused_mut)]
+#![allow(clippy::toplevel_ref_arg, drop_ref, clippy::forget_ref, unused_mut)]
 
 use std::mem::{drop, forget};
 use std::vec::Vec;
diff --git a/src/tools/clippy/tests/ui/drop_ref.rs b/src/tools/clippy/tests/ui/drop_ref.rs
deleted file mode 100644
index 10044e65f11..00000000000
--- a/src/tools/clippy/tests/ui/drop_ref.rs
+++ /dev/null
@@ -1,97 +0,0 @@
-#![warn(clippy::drop_ref)]
-#![allow(clippy::toplevel_ref_arg)]
-#![allow(clippy::map_err_ignore)]
-#![allow(clippy::unnecessary_wraps, clippy::drop_non_drop)]
-
-use std::mem::drop;
-
-struct SomeStruct;
-
-fn main() {
-    drop(&SomeStruct);
-
-    let mut owned1 = SomeStruct;
-    drop(&owned1);
-    drop(&&owned1);
-    drop(&mut owned1);
-    drop(owned1); //OK
-
-    let reference1 = &SomeStruct;
-    drop(reference1);
-
-    let reference2 = &mut SomeStruct;
-    drop(reference2);
-
-    let ref reference3 = SomeStruct;
-    drop(reference3);
-}
-
-#[allow(dead_code)]
-fn test_generic_fn_drop<T>(val: T) {
-    drop(&val);
-    drop(val); //OK
-}
-
-#[allow(dead_code)]
-fn test_similarly_named_function() {
-    fn drop<T>(_val: T) {}
-    drop(&SomeStruct); //OK; call to unrelated function which happens to have the same name
-    std::mem::drop(&SomeStruct);
-}
-
-#[derive(Copy, Clone)]
-pub struct Error;
-fn produce_half_owl_error() -> Result<(), Error> {
-    Ok(())
-}
-
-fn produce_half_owl_ok() -> Result<bool, ()> {
-    Ok(true)
-}
-
-#[allow(dead_code)]
-fn test_owl_result() -> Result<(), ()> {
-    produce_half_owl_error().map_err(|_| ())?;
-    produce_half_owl_ok().map(|_| ())?;
-    // the following should not be linted,
-    // we should not force users to use toilet closures
-    // to produce owl results when drop is more convenient
-    produce_half_owl_error().map_err(drop)?;
-    produce_half_owl_ok().map_err(drop)?;
-    Ok(())
-}
-
-#[allow(dead_code)]
-fn test_owl_result_2() -> Result<u8, ()> {
-    produce_half_owl_error().map_err(|_| ())?;
-    produce_half_owl_ok().map(|_| ())?;
-    // the following should not be linted,
-    // we should not force users to use toilet closures
-    // to produce owl results when drop is more convenient
-    produce_half_owl_error().map_err(drop)?;
-    produce_half_owl_ok().map(drop)?;
-    Ok(1)
-}
-
-#[allow(unused)]
-#[allow(clippy::unit_cmp)]
-fn issue10122(x: u8) {
-    // This is a function which returns a reference and has a side-effect, which means
-    // that calling drop() on the function is considered an idiomatic way of achieving the side-effect
-    // in a match arm.
-    fn println_and<T>(t: &T) -> &T {
-        println!("foo");
-        t
-    }
-
-    match x {
-        0 => drop(println_and(&12)), // Don't lint (copy type), we only care about side-effects
-        1 => drop(println_and(&String::new())), // Don't lint (no copy type), we only care about side-effects
-        2 => {
-            drop(println_and(&13)); // Lint, even if we only care about the side-effect, it's already in a block
-        },
-        3 if drop(println_and(&14)) == () => (), // Lint, idiomatic use is only in body of `Arm`
-        4 => drop(&2),                           // Lint, not a fn/method call
-        _ => (),
-    }
-}
diff --git a/src/tools/clippy/tests/ui/drop_ref.stderr b/src/tools/clippy/tests/ui/drop_ref.stderr
deleted file mode 100644
index 293b9f6de83..00000000000
--- a/src/tools/clippy/tests/ui/drop_ref.stderr
+++ /dev/null
@@ -1,147 +0,0 @@
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:11:5
-   |
-LL |     drop(&SomeStruct);
-   |     ^^^^^^^^^^^^^^^^^
-   |
-note: argument has type `&SomeStruct`
-  --> $DIR/drop_ref.rs:11:10
-   |
-LL |     drop(&SomeStruct);
-   |          ^^^^^^^^^^^
-   = note: `-D clippy::drop-ref` implied by `-D warnings`
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:14:5
-   |
-LL |     drop(&owned1);
-   |     ^^^^^^^^^^^^^
-   |
-note: argument has type `&SomeStruct`
-  --> $DIR/drop_ref.rs:14:10
-   |
-LL |     drop(&owned1);
-   |          ^^^^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:15:5
-   |
-LL |     drop(&&owned1);
-   |     ^^^^^^^^^^^^^^
-   |
-note: argument has type `&&SomeStruct`
-  --> $DIR/drop_ref.rs:15:10
-   |
-LL |     drop(&&owned1);
-   |          ^^^^^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:16:5
-   |
-LL |     drop(&mut owned1);
-   |     ^^^^^^^^^^^^^^^^^
-   |
-note: argument has type `&mut SomeStruct`
-  --> $DIR/drop_ref.rs:16:10
-   |
-LL |     drop(&mut owned1);
-   |          ^^^^^^^^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:20:5
-   |
-LL |     drop(reference1);
-   |     ^^^^^^^^^^^^^^^^
-   |
-note: argument has type `&SomeStruct`
-  --> $DIR/drop_ref.rs:20:10
-   |
-LL |     drop(reference1);
-   |          ^^^^^^^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:23:5
-   |
-LL |     drop(reference2);
-   |     ^^^^^^^^^^^^^^^^
-   |
-note: argument has type `&mut SomeStruct`
-  --> $DIR/drop_ref.rs:23:10
-   |
-LL |     drop(reference2);
-   |          ^^^^^^^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:26:5
-   |
-LL |     drop(reference3);
-   |     ^^^^^^^^^^^^^^^^
-   |
-note: argument has type `&SomeStruct`
-  --> $DIR/drop_ref.rs:26:10
-   |
-LL |     drop(reference3);
-   |          ^^^^^^^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:31:5
-   |
-LL |     drop(&val);
-   |     ^^^^^^^^^^
-   |
-note: argument has type `&T`
-  --> $DIR/drop_ref.rs:31:10
-   |
-LL |     drop(&val);
-   |          ^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:39:5
-   |
-LL |     std::mem::drop(&SomeStruct);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: argument has type `&SomeStruct`
-  --> $DIR/drop_ref.rs:39:20
-   |
-LL |     std::mem::drop(&SomeStruct);
-   |                    ^^^^^^^^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:91:13
-   |
-LL |             drop(println_and(&13)); // Lint, even if we only care about the side-effect, it's already in a block
-   |             ^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: argument has type `&i32`
-  --> $DIR/drop_ref.rs:91:18
-   |
-LL |             drop(println_and(&13)); // Lint, even if we only care about the side-effect, it's already in a block
-   |                  ^^^^^^^^^^^^^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:93:14
-   |
-LL |         3 if drop(println_and(&14)) == () => (), // Lint, idiomatic use is only in body of `Arm`
-   |              ^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: argument has type `&i32`
-  --> $DIR/drop_ref.rs:93:19
-   |
-LL |         3 if drop(println_and(&14)) == () => (), // Lint, idiomatic use is only in body of `Arm`
-   |                   ^^^^^^^^^^^^^^^^
-
-error: calls to `std::mem::drop` with a reference instead of an owned value. Dropping a reference does nothing
-  --> $DIR/drop_ref.rs:94:14
-   |
-LL |         4 => drop(&2),                           // Lint, not a fn/method call
-   |              ^^^^^^^^
-   |
-note: argument has type `&i32`
-  --> $DIR/drop_ref.rs:94:19
-   |
-LL |         4 => drop(&2),                           // Lint, not a fn/method call
-   |                   ^^
-
-error: aborting due to 12 previous errors
-
diff --git a/src/tools/clippy/tests/ui/rename.fixed b/src/tools/clippy/tests/ui/rename.fixed
index 42a59f6d43d..1beb878fc75 100644
--- a/src/tools/clippy/tests/ui/rename.fixed
+++ b/src/tools/clippy/tests/ui/rename.fixed
@@ -29,6 +29,7 @@
 #![allow(clippy::invisible_characters)]
 #![allow(suspicious_double_ref_op)]
 #![allow(drop_bounds)]
+#![allow(drop_ref)]
 #![allow(for_loops_over_fallibles)]
 #![allow(array_into_iter)]
 #![allow(invalid_atomic_ordering)]
@@ -71,6 +72,7 @@
 #![warn(clippy::invisible_characters)]
 #![warn(suspicious_double_ref_op)]
 #![warn(drop_bounds)]
+#![warn(drop_ref)]
 #![warn(for_loops_over_fallibles)]
 #![warn(for_loops_over_fallibles)]
 #![warn(for_loops_over_fallibles)]
diff --git a/src/tools/clippy/tests/ui/rename.rs b/src/tools/clippy/tests/ui/rename.rs
index 4d173e8cbbf..7034daffdd6 100644
--- a/src/tools/clippy/tests/ui/rename.rs
+++ b/src/tools/clippy/tests/ui/rename.rs
@@ -29,6 +29,7 @@
 #![allow(clippy::invisible_characters)]
 #![allow(suspicious_double_ref_op)]
 #![allow(drop_bounds)]
+#![allow(drop_ref)]
 #![allow(for_loops_over_fallibles)]
 #![allow(array_into_iter)]
 #![allow(invalid_atomic_ordering)]
@@ -71,6 +72,7 @@
 #![warn(clippy::zero_width_space)]
 #![warn(clippy::clone_double_ref)]
 #![warn(clippy::drop_bounds)]
+#![warn(clippy::drop_ref)]
 #![warn(clippy::for_loop_over_option)]
 #![warn(clippy::for_loop_over_result)]
 #![warn(clippy::for_loops_over_fallibles)]
diff --git a/src/tools/clippy/tests/ui/rename.stderr b/src/tools/clippy/tests/ui/rename.stderr
index 0da4ed7520c..7cf5562a7e3 100644
--- a/src/tools/clippy/tests/ui/rename.stderr
+++ b/src/tools/clippy/tests/ui/rename.stderr
@@ -1,5 +1,5 @@
 error: lint `clippy::almost_complete_letter_range` has been renamed to `clippy::almost_complete_range`
-  --> $DIR/rename.rs:44:9
+  --> $DIR/rename.rs:45:9
    |
 LL | #![warn(clippy::almost_complete_letter_range)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::almost_complete_range`
@@ -7,256 +7,262 @@ LL | #![warn(clippy::almost_complete_letter_range)]
    = note: `-D renamed-and-removed-lints` implied by `-D warnings`
 
 error: lint `clippy::blacklisted_name` has been renamed to `clippy::disallowed_names`
-  --> $DIR/rename.rs:45:9
+  --> $DIR/rename.rs:46:9
    |
 LL | #![warn(clippy::blacklisted_name)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::disallowed_names`
 
 error: lint `clippy::block_in_if_condition_expr` has been renamed to `clippy::blocks_in_if_conditions`
-  --> $DIR/rename.rs:46:9
+  --> $DIR/rename.rs:47:9
    |
 LL | #![warn(clippy::block_in_if_condition_expr)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::blocks_in_if_conditions`
 
 error: lint `clippy::block_in_if_condition_stmt` has been renamed to `clippy::blocks_in_if_conditions`
-  --> $DIR/rename.rs:47:9
+  --> $DIR/rename.rs:48:9
    |
 LL | #![warn(clippy::block_in_if_condition_stmt)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::blocks_in_if_conditions`
 
 error: lint `clippy::box_vec` has been renamed to `clippy::box_collection`
-  --> $DIR/rename.rs:48:9
+  --> $DIR/rename.rs:49:9
    |
 LL | #![warn(clippy::box_vec)]
    |         ^^^^^^^^^^^^^^^ help: use the new name: `clippy::box_collection`
 
 error: lint `clippy::const_static_lifetime` has been renamed to `clippy::redundant_static_lifetimes`
-  --> $DIR/rename.rs:49:9
+  --> $DIR/rename.rs:50:9
    |
 LL | #![warn(clippy::const_static_lifetime)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::redundant_static_lifetimes`
 
 error: lint `clippy::cyclomatic_complexity` has been renamed to `clippy::cognitive_complexity`
-  --> $DIR/rename.rs:50:9
+  --> $DIR/rename.rs:51:9
    |
 LL | #![warn(clippy::cyclomatic_complexity)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::cognitive_complexity`
 
 error: lint `clippy::derive_hash_xor_eq` has been renamed to `clippy::derived_hash_with_manual_eq`
-  --> $DIR/rename.rs:51:9
+  --> $DIR/rename.rs:52:9
    |
 LL | #![warn(clippy::derive_hash_xor_eq)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::derived_hash_with_manual_eq`
 
 error: lint `clippy::disallowed_method` has been renamed to `clippy::disallowed_methods`
-  --> $DIR/rename.rs:52:9
+  --> $DIR/rename.rs:53:9
    |
 LL | #![warn(clippy::disallowed_method)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::disallowed_methods`
 
 error: lint `clippy::disallowed_type` has been renamed to `clippy::disallowed_types`
-  --> $DIR/rename.rs:53:9
+  --> $DIR/rename.rs:54:9
    |
 LL | #![warn(clippy::disallowed_type)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::disallowed_types`
 
 error: lint `clippy::eval_order_dependence` has been renamed to `clippy::mixed_read_write_in_expression`
-  --> $DIR/rename.rs:54:9
+  --> $DIR/rename.rs:55:9
    |
 LL | #![warn(clippy::eval_order_dependence)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::mixed_read_write_in_expression`
 
 error: lint `clippy::identity_conversion` has been renamed to `clippy::useless_conversion`
-  --> $DIR/rename.rs:55:9
+  --> $DIR/rename.rs:56:9
    |
 LL | #![warn(clippy::identity_conversion)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::useless_conversion`
 
 error: lint `clippy::if_let_some_result` has been renamed to `clippy::match_result_ok`
-  --> $DIR/rename.rs:56:9
+  --> $DIR/rename.rs:57:9
    |
 LL | #![warn(clippy::if_let_some_result)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::match_result_ok`
 
 error: lint `clippy::logic_bug` has been renamed to `clippy::overly_complex_bool_expr`
-  --> $DIR/rename.rs:57:9
+  --> $DIR/rename.rs:58:9
    |
 LL | #![warn(clippy::logic_bug)]
    |         ^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::overly_complex_bool_expr`
 
 error: lint `clippy::new_without_default_derive` has been renamed to `clippy::new_without_default`
-  --> $DIR/rename.rs:58:9
+  --> $DIR/rename.rs:59:9
    |
 LL | #![warn(clippy::new_without_default_derive)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::new_without_default`
 
 error: lint `clippy::option_and_then_some` has been renamed to `clippy::bind_instead_of_map`
-  --> $DIR/rename.rs:59:9
+  --> $DIR/rename.rs:60:9
    |
 LL | #![warn(clippy::option_and_then_some)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::bind_instead_of_map`
 
 error: lint `clippy::option_expect_used` has been renamed to `clippy::expect_used`
-  --> $DIR/rename.rs:60:9
+  --> $DIR/rename.rs:61:9
    |
 LL | #![warn(clippy::option_expect_used)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::expect_used`
 
 error: lint `clippy::option_map_unwrap_or` has been renamed to `clippy::map_unwrap_or`
-  --> $DIR/rename.rs:61:9
+  --> $DIR/rename.rs:62:9
    |
 LL | #![warn(clippy::option_map_unwrap_or)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::map_unwrap_or`
 
 error: lint `clippy::option_map_unwrap_or_else` has been renamed to `clippy::map_unwrap_or`
-  --> $DIR/rename.rs:62:9
+  --> $DIR/rename.rs:63:9
    |
 LL | #![warn(clippy::option_map_unwrap_or_else)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::map_unwrap_or`
 
 error: lint `clippy::option_unwrap_used` has been renamed to `clippy::unwrap_used`
-  --> $DIR/rename.rs:63:9
+  --> $DIR/rename.rs:64:9
    |
 LL | #![warn(clippy::option_unwrap_used)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::unwrap_used`
 
 error: lint `clippy::ref_in_deref` has been renamed to `clippy::needless_borrow`
-  --> $DIR/rename.rs:64:9
+  --> $DIR/rename.rs:65:9
    |
 LL | #![warn(clippy::ref_in_deref)]
    |         ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::needless_borrow`
 
 error: lint `clippy::result_expect_used` has been renamed to `clippy::expect_used`
-  --> $DIR/rename.rs:65:9
+  --> $DIR/rename.rs:66:9
    |
 LL | #![warn(clippy::result_expect_used)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::expect_used`
 
 error: lint `clippy::result_map_unwrap_or_else` has been renamed to `clippy::map_unwrap_or`
-  --> $DIR/rename.rs:66:9
+  --> $DIR/rename.rs:67:9
    |
 LL | #![warn(clippy::result_map_unwrap_or_else)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::map_unwrap_or`
 
 error: lint `clippy::result_unwrap_used` has been renamed to `clippy::unwrap_used`
-  --> $DIR/rename.rs:67:9
+  --> $DIR/rename.rs:68:9
    |
 LL | #![warn(clippy::result_unwrap_used)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::unwrap_used`
 
 error: lint `clippy::single_char_push_str` has been renamed to `clippy::single_char_add_str`
-  --> $DIR/rename.rs:68:9
+  --> $DIR/rename.rs:69:9
    |
 LL | #![warn(clippy::single_char_push_str)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::single_char_add_str`
 
 error: lint `clippy::stutter` has been renamed to `clippy::module_name_repetitions`
-  --> $DIR/rename.rs:69:9
+  --> $DIR/rename.rs:70:9
    |
 LL | #![warn(clippy::stutter)]
    |         ^^^^^^^^^^^^^^^ help: use the new name: `clippy::module_name_repetitions`
 
 error: lint `clippy::to_string_in_display` has been renamed to `clippy::recursive_format_impl`
-  --> $DIR/rename.rs:70:9
+  --> $DIR/rename.rs:71:9
    |
 LL | #![warn(clippy::to_string_in_display)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::recursive_format_impl`
 
 error: lint `clippy::zero_width_space` has been renamed to `clippy::invisible_characters`
-  --> $DIR/rename.rs:71:9
+  --> $DIR/rename.rs:72:9
    |
 LL | #![warn(clippy::zero_width_space)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::invisible_characters`
 
 error: lint `clippy::clone_double_ref` has been renamed to `suspicious_double_ref_op`
-  --> $DIR/rename.rs:72:9
+  --> $DIR/rename.rs:73:9
    |
 LL | #![warn(clippy::clone_double_ref)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `suspicious_double_ref_op`
 
 error: lint `clippy::drop_bounds` has been renamed to `drop_bounds`
-  --> $DIR/rename.rs:73:9
+  --> $DIR/rename.rs:74:9
    |
 LL | #![warn(clippy::drop_bounds)]
    |         ^^^^^^^^^^^^^^^^^^^ help: use the new name: `drop_bounds`
 
+error: lint `clippy::drop_ref` has been renamed to `drop_ref`
+  --> $DIR/rename.rs:75:9
+   |
+LL | #![warn(clippy::drop_ref)]
+   |         ^^^^^^^^^^^^^^^^ help: use the new name: `drop_ref`
+
 error: lint `clippy::for_loop_over_option` has been renamed to `for_loops_over_fallibles`
-  --> $DIR/rename.rs:74:9
+  --> $DIR/rename.rs:76:9
    |
 LL | #![warn(clippy::for_loop_over_option)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles`
 
 error: lint `clippy::for_loop_over_result` has been renamed to `for_loops_over_fallibles`
-  --> $DIR/rename.rs:75:9
+  --> $DIR/rename.rs:77:9
    |
 LL | #![warn(clippy::for_loop_over_result)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles`
 
 error: lint `clippy::for_loops_over_fallibles` has been renamed to `for_loops_over_fallibles`
-  --> $DIR/rename.rs:76:9
+  --> $DIR/rename.rs:78:9
    |
 LL | #![warn(clippy::for_loops_over_fallibles)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles`
 
 error: lint `clippy::into_iter_on_array` has been renamed to `array_into_iter`
-  --> $DIR/rename.rs:77:9
+  --> $DIR/rename.rs:79:9
    |
 LL | #![warn(clippy::into_iter_on_array)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `array_into_iter`
 
 error: lint `clippy::invalid_atomic_ordering` has been renamed to `invalid_atomic_ordering`
-  --> $DIR/rename.rs:78:9
+  --> $DIR/rename.rs:80:9
    |
 LL | #![warn(clippy::invalid_atomic_ordering)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_atomic_ordering`
 
 error: lint `clippy::invalid_ref` has been renamed to `invalid_value`
-  --> $DIR/rename.rs:79:9
+  --> $DIR/rename.rs:81:9
    |
 LL | #![warn(clippy::invalid_ref)]
    |         ^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_value`
 
 error: lint `clippy::let_underscore_drop` has been renamed to `let_underscore_drop`
-  --> $DIR/rename.rs:80:9
+  --> $DIR/rename.rs:82:9
    |
 LL | #![warn(clippy::let_underscore_drop)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `let_underscore_drop`
 
 error: lint `clippy::mem_discriminant_non_enum` has been renamed to `enum_intrinsics_non_enums`
-  --> $DIR/rename.rs:81:9
+  --> $DIR/rename.rs:83:9
    |
 LL | #![warn(clippy::mem_discriminant_non_enum)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `enum_intrinsics_non_enums`
 
 error: lint `clippy::panic_params` has been renamed to `non_fmt_panics`
-  --> $DIR/rename.rs:82:9
+  --> $DIR/rename.rs:84:9
    |
 LL | #![warn(clippy::panic_params)]
    |         ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `non_fmt_panics`
 
 error: lint `clippy::positional_named_format_parameters` has been renamed to `named_arguments_used_positionally`
-  --> $DIR/rename.rs:83:9
+  --> $DIR/rename.rs:85:9
    |
 LL | #![warn(clippy::positional_named_format_parameters)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `named_arguments_used_positionally`
 
 error: lint `clippy::temporary_cstring_as_ptr` has been renamed to `temporary_cstring_as_ptr`
-  --> $DIR/rename.rs:84:9
+  --> $DIR/rename.rs:86:9
    |
 LL | #![warn(clippy::temporary_cstring_as_ptr)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `temporary_cstring_as_ptr`
 
 error: lint `clippy::unknown_clippy_lints` has been renamed to `unknown_lints`
-  --> $DIR/rename.rs:85:9
+  --> $DIR/rename.rs:87:9
    |
 LL | #![warn(clippy::unknown_clippy_lints)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unknown_lints`
 
 error: lint `clippy::unused_label` has been renamed to `unused_labels`
-  --> $DIR/rename.rs:86:9
+  --> $DIR/rename.rs:88:9
    |
 LL | #![warn(clippy::unused_label)]
    |         ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unused_labels`
 
-error: aborting due to 43 previous errors
+error: aborting due to 44 previous errors