From 5c99175a9efcaa3d65712c119f361add22e3a859 Mon Sep 17 00:00:00 2001 From: Deadbeef Date: Fri, 28 Apr 2023 17:17:46 +0000 Subject: [PATCH] uplift `clippy::clone_double_ref` as `suspicious_double_ref_op` --- compiler/rustc_codegen_ssa/src/back/link.rs | 7 +- compiler/rustc_lint/messages.ftl | 3 + compiler/rustc_lint/src/lints.rs | 8 ++ compiler/rustc_lint/src/noop_method_call.rs | 81 ++++++++++++---- .../clippy/clippy_lints/src/declared_lints.rs | 1 - .../clippy_lints/src/methods/clone_on_copy.rs | 40 +------- .../clippy/clippy_lints/src/methods/mod.rs | 24 ----- .../clippy/clippy_lints/src/renamed_lints.rs | 1 + .../tests/ui/explicit_deref_methods.fixed | 2 +- .../clippy/tests/ui/explicit_deref_methods.rs | 2 +- src/tools/clippy/tests/ui/rename.fixed | 2 + src/tools/clippy/tests/ui/rename.rs | 2 + src/tools/clippy/tests/ui/rename.stderr | 92 ++++++++++--------- .../clippy/tests/ui/unnecessary_clone.rs | 13 --- .../clippy/tests/ui/unnecessary_clone.stderr | 52 +---------- tests/ui/lint/noop-method-call.rs | 8 +- tests/ui/lint/noop-method-call.stderr | 26 +++++- tests/ui/lint/suspicious-double-ref-op.rs | 30 ++++++ tests/ui/lint/suspicious-double-ref-op.stderr | 35 +++++++ 19 files changed, 230 insertions(+), 199 deletions(-) create mode 100644 tests/ui/lint/suspicious-double-ref-op.rs create mode 100644 tests/ui/lint/suspicious-double-ref-op.stderr diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs index 02e21e74fad..802e99a5e0e 100644 --- a/compiler/rustc_codegen_ssa/src/back/link.rs +++ b/compiler/rustc_codegen_ssa/src/back/link.rs @@ -40,7 +40,6 @@ use regex::Regex; use tempfile::Builder as TempFileBuilder; use itertools::Itertools; -use std::borrow::Borrow; use std::cell::OnceCell; use std::collections::BTreeSet; use std::ffi::OsString; @@ -573,17 +572,17 @@ fn link_dwarf_object<'a>( impl ThorinSession { fn alloc_mmap(&self, data: Mmap) -> &Mmap { - (*self.arena_mmap.alloc(data)).borrow() + &*self.arena_mmap.alloc(data) } } impl thorin::Session for ThorinSession { fn alloc_data(&self, data: Vec) -> &[u8] { - (*self.arena_data.alloc(data)).borrow() + &*self.arena_data.alloc(data) } fn alloc_relocation(&self, data: Relocations) -> &Relocations { - (*self.arena_relocations.alloc(data)).borrow() + &*self.arena_relocations.alloc(data) } fn read_input(&self, path: &Path) -> std::io::Result<&[u8]> { diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl index 3c6dbb466db..0cef6a44b07 100644 --- a/compiler/rustc_lint/messages.ftl +++ b/compiler/rustc_lint/messages.ftl @@ -50,6 +50,9 @@ lint_deprecated_lint_name = lint_renamed_or_removed_lint = {$msg} .suggestion = use the new name +lint_suspicious_double_ref_op = + using `.{$call}()` on a double reference, which returns `{$ty}` instead of {$op} the inner type + lint_unknown_lint = unknown lint: `{$name}` .suggestion = did you mean diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs index 848f6a9ecb5..d7bacc6485f 100644 --- a/compiler/rustc_lint/src/lints.rs +++ b/compiler/rustc_lint/src/lints.rs @@ -1150,6 +1150,14 @@ pub struct NoopMethodCallDiag<'a> { pub label: Span, } +#[derive(LintDiagnostic)] +#[diag(lint_suspicious_double_ref_op)] +pub struct SuspiciousDoubleRefDiag<'a> { + pub call: Symbol, + pub ty: Ty<'a>, + pub op: &'static str, +} + // pass_by_value.rs #[derive(LintDiagnostic)] #[diag(lint_pass_by_value)] diff --git a/compiler/rustc_lint/src/noop_method_call.rs b/compiler/rustc_lint/src/noop_method_call.rs index d67a00619dd..648c0c26404 100644 --- a/compiler/rustc_lint/src/noop_method_call.rs +++ b/compiler/rustc_lint/src/noop_method_call.rs @@ -1,10 +1,11 @@ use crate::context::LintContext; -use crate::lints::NoopMethodCallDiag; +use crate::lints::{NoopMethodCallDiag, SuspiciousDoubleRefDiag}; use crate::LateContext; use crate::LateLintPass; use rustc_hir::def::DefKind; use rustc_hir::{Expr, ExprKind}; use rustc_middle::ty; +use rustc_middle::ty::adjustment::Adjust; use rustc_span::symbol::sym; declare_lint! { @@ -35,14 +36,44 @@ declare_lint! { "detects the use of well-known noop methods" } -declare_lint_pass!(NoopMethodCall => [NOOP_METHOD_CALL]); +declare_lint! { + /// The `suspicious_double_ref_op` lint checks for usage of `.clone()`/`.borrow()`/`.deref()` + /// on an `&&T` when `T: !Deref/Borrow/Clone`, which means the call will return the inner `&T`, + /// instead of performing the operation on the underlying `T` and can be confusing. + /// + /// ### Example + /// + /// ```rust + /// # #![allow(unused)] + /// struct Foo; + /// let foo = &&Foo; + /// let clone: &Foo = foo.clone(); + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// Since `Foo` doesn't implement `Clone`, running `.clone()` only dereferences the double + /// reference, instead of cloning the inner type which should be what was intended. + pub SUSPICIOUS_DOUBLE_REF_OP, + Warn, + "suspicious call of trait method on `&&T`" +} + +declare_lint_pass!(NoopMethodCall => [NOOP_METHOD_CALL, SUSPICIOUS_DOUBLE_REF_OP]); impl<'tcx> LateLintPass<'tcx> for NoopMethodCall { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { // We only care about method calls. - let ExprKind::MethodCall(call, receiver, ..) = &expr.kind else { - return + let ExprKind::MethodCall(call, receiver, _, call_span) = &expr.kind else { + return; }; + + if call_span.from_expansion() { + return; + } + // We only care about method calls corresponding to the `Clone`, `Deref` and `Borrow` // traits and ignore any other method call. let did = match cx.typeck_results().type_dependent_def(expr.hir_id) { @@ -70,25 +101,39 @@ impl<'tcx> LateLintPass<'tcx> for NoopMethodCall { }; // (Re)check that it implements the noop diagnostic. let Some(name) = cx.tcx.get_diagnostic_name(i.def_id()) else { return }; - if !matches!( - name, - sym::noop_method_borrow | sym::noop_method_clone | sym::noop_method_deref - ) { - return; - } + + let op = match name { + sym::noop_method_borrow => "borrowing", + sym::noop_method_clone => "cloning", + sym::noop_method_deref => "dereferencing", + _ => return, + }; + let receiver_ty = cx.typeck_results().expr_ty(receiver); let expr_ty = cx.typeck_results().expr_ty_adjusted(expr); - if receiver_ty != expr_ty { - // This lint will only trigger if the receiver type and resulting expression \ - // type are the same, implying that the method call is unnecessary. + let arg_adjustments = cx.typeck_results().expr_adjustments(receiver); + + // If there is any user defined auto-deref step, then we don't want to warn. + // https://github.com/rust-lang/rust-clippy/issues/9272 + if arg_adjustments.iter().any(|adj| matches!(adj.kind, Adjust::Deref(Some(_)))) { return; } + let expr_span = expr.span; let span = expr_span.with_lo(receiver.span.hi()); - cx.emit_spanned_lint( - NOOP_METHOD_CALL, - span, - NoopMethodCallDiag { method: call.ident.name, receiver_ty, label: span }, - ); + + if receiver_ty == expr_ty { + cx.emit_spanned_lint( + NOOP_METHOD_CALL, + span, + NoopMethodCallDiag { method: call.ident.name, receiver_ty, label: span }, + ); + } else { + cx.emit_spanned_lint( + SUSPICIOUS_DOUBLE_REF_OP, + span, + SuspiciousDoubleRefDiag { call: call.ident.name, ty: expr_ty, op }, + ) + } } } diff --git a/src/tools/clippy/clippy_lints/src/declared_lints.rs b/src/tools/clippy/clippy_lints/src/declared_lints.rs index 0c66d36a1d6..fa726a64937 100644 --- a/src/tools/clippy/clippy_lints/src/declared_lints.rs +++ b/src/tools/clippy/clippy_lints/src/declared_lints.rs @@ -313,7 +313,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::methods::CHARS_NEXT_CMP_INFO, crate::methods::CLEAR_WITH_DRAIN_INFO, crate::methods::CLONED_INSTEAD_OF_COPIED_INFO, - crate::methods::CLONE_DOUBLE_REF_INFO, crate::methods::CLONE_ON_COPY_INFO, crate::methods::CLONE_ON_REF_PTR_INFO, crate::methods::COLLAPSIBLE_STR_REPLACE_INFO, diff --git a/src/tools/clippy/clippy_lints/src/methods/clone_on_copy.rs b/src/tools/clippy/clippy_lints/src/methods/clone_on_copy.rs index 3795c0ec250..65fd50dff58 100644 --- a/src/tools/clippy/clippy_lints/src/methods/clone_on_copy.rs +++ b/src/tools/clippy/clippy_lints/src/methods/clone_on_copy.rs @@ -1,7 +1,6 @@ -use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then}; +use clippy_utils::diagnostics::span_lint_and_sugg; use clippy_utils::get_parent_node; use clippy_utils::source::snippet_with_context; -use clippy_utils::sugg; use clippy_utils::ty::is_copy; use rustc_errors::Applicability; use rustc_hir::{BindingAnnotation, ByRef, Expr, ExprKind, MatchSource, Node, PatKind, QPath}; @@ -9,7 +8,6 @@ use rustc_lint::LateContext; use rustc_middle::ty::{self, adjustment::Adjust, print::with_forced_trimmed_paths}; use rustc_span::symbol::{sym, Symbol}; -use super::CLONE_DOUBLE_REF; use super::CLONE_ON_COPY; /// Checks for the `CLONE_ON_COPY` lint. @@ -42,41 +40,7 @@ pub(super) fn check( let ty = cx.typeck_results().expr_ty(expr); if let ty::Ref(_, inner, _) = arg_ty.kind() { - if let ty::Ref(_, innermost, _) = inner.kind() { - span_lint_and_then( - cx, - CLONE_DOUBLE_REF, - expr.span, - &with_forced_trimmed_paths!(format!( - "using `clone` on a double-reference; \ - this will copy the reference of type `{ty}` instead of cloning the inner type" - )), - |diag| { - if let Some(snip) = sugg::Sugg::hir_opt(cx, arg) { - let mut ty = innermost; - let mut n = 0; - while let ty::Ref(_, inner, _) = ty.kind() { - ty = inner; - n += 1; - } - let refs = "&".repeat(n + 1); - let derefs = "*".repeat(n); - let explicit = with_forced_trimmed_paths!(format!("<{refs}{ty}>::clone({snip})")); - diag.span_suggestion( - expr.span, - "try dereferencing it", - with_forced_trimmed_paths!(format!("{refs}({derefs}{}).clone()", snip.deref())), - Applicability::MaybeIncorrect, - ); - diag.span_suggestion( - expr.span, - "or try being explicit if you are sure, that you want to clone a reference", - explicit, - Applicability::MaybeIncorrect, - ); - } - }, - ); + if let ty::Ref(..) = inner.kind() { return; // don't report clone_on_copy } } diff --git a/src/tools/clippy/clippy_lints/src/methods/mod.rs b/src/tools/clippy/clippy_lints/src/methods/mod.rs index 9cafbc2e5f5..e4a659d3ce7 100644 --- a/src/tools/clippy/clippy_lints/src/methods/mod.rs +++ b/src/tools/clippy/clippy_lints/src/methods/mod.rs @@ -984,29 +984,6 @@ declare_clippy_lint! { "using 'clone' on a ref-counted pointer" } -declare_clippy_lint! { - /// ### What it does - /// Checks for usage of `.clone()` on an `&&T`. - /// - /// ### Why is this bad? - /// Cloning an `&&T` copies the inner `&T`, instead of - /// cloning the underlying `T`. - /// - /// ### Example - /// ```rust - /// fn main() { - /// let x = vec![1]; - /// let y = &&x; - /// let z = y.clone(); - /// println!("{:p} {:p}", *y, z); // prints out the same pointer - /// } - /// ``` - #[clippy::version = "pre 1.29.0"] - pub CLONE_DOUBLE_REF, - correctness, - "using `clone` on `&&T`" -} - declare_clippy_lint! { /// ### What it does /// Checks for usage of `.to_string()` on an `&&T` where @@ -3258,7 +3235,6 @@ impl_lint_pass!(Methods => [ CHARS_LAST_CMP, CLONE_ON_COPY, CLONE_ON_REF_PTR, - CLONE_DOUBLE_REF, COLLAPSIBLE_STR_REPLACE, ITER_OVEREAGER_CLONED, CLONED_INSTEAD_OF_COPIED, diff --git a/src/tools/clippy/clippy_lints/src/renamed_lints.rs b/src/tools/clippy/clippy_lints/src/renamed_lints.rs index 9f487dedb8c..5e81a01a461 100644 --- a/src/tools/clippy/clippy_lints/src/renamed_lints.rs +++ b/src/tools/clippy/clippy_lints/src/renamed_lints.rs @@ -30,6 +30,7 @@ pub static RENAMED_LINTS: &[(&str, &str)] = &[ ("clippy::stutter", "clippy::module_name_repetitions"), ("clippy::to_string_in_display", "clippy::recursive_format_impl"), ("clippy::zero_width_space", "clippy::invisible_characters"), + ("clippy::clone_double_ref", "suspicious_double_ref_op"), ("clippy::drop_bounds", "drop_bounds"), ("clippy::for_loop_over_option", "for_loops_over_fallibles"), ("clippy::for_loop_over_result", "for_loops_over_fallibles"), diff --git a/src/tools/clippy/tests/ui/explicit_deref_methods.fixed b/src/tools/clippy/tests/ui/explicit_deref_methods.fixed index 77e9f5fc1fd..60482c66da7 100644 --- a/src/tools/clippy/tests/ui/explicit_deref_methods.fixed +++ b/src/tools/clippy/tests/ui/explicit_deref_methods.fixed @@ -3,7 +3,7 @@ #![allow(unused_variables)] #![allow( clippy::borrow_deref_ref, - clippy::clone_double_ref, + suspicious_double_ref_op, clippy::explicit_auto_deref, clippy::needless_borrow, clippy::uninlined_format_args diff --git a/src/tools/clippy/tests/ui/explicit_deref_methods.rs b/src/tools/clippy/tests/ui/explicit_deref_methods.rs index 0c2cc7c2c3a..e3613e216bb 100644 --- a/src/tools/clippy/tests/ui/explicit_deref_methods.rs +++ b/src/tools/clippy/tests/ui/explicit_deref_methods.rs @@ -3,7 +3,7 @@ #![allow(unused_variables)] #![allow( clippy::borrow_deref_ref, - clippy::clone_double_ref, + suspicious_double_ref_op, clippy::explicit_auto_deref, clippy::needless_borrow, clippy::uninlined_format_args diff --git a/src/tools/clippy/tests/ui/rename.fixed b/src/tools/clippy/tests/ui/rename.fixed index e8a00a9e7f7..ff19a042825 100644 --- a/src/tools/clippy/tests/ui/rename.fixed +++ b/src/tools/clippy/tests/ui/rename.fixed @@ -36,6 +36,7 @@ #![allow(enum_intrinsics_non_enums)] #![allow(non_fmt_panics)] #![allow(named_arguments_used_positionally)] +#![allow(suspicious_double_ref_op)] #![allow(temporary_cstring_as_ptr)] #![allow(unknown_lints)] #![allow(unused_labels)] @@ -67,6 +68,7 @@ #![warn(clippy::module_name_repetitions)] #![warn(clippy::recursive_format_impl)] #![warn(clippy::invisible_characters)] +#![warn(suspicious_double_ref_op)] #![warn(drop_bounds)] #![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 c8ea70c2bcb..38b1647c0cc 100644 --- a/src/tools/clippy/tests/ui/rename.rs +++ b/src/tools/clippy/tests/ui/rename.rs @@ -36,6 +36,7 @@ #![allow(enum_intrinsics_non_enums)] #![allow(non_fmt_panics)] #![allow(named_arguments_used_positionally)] +#![allow(suspicious_double_ref_op)] #![allow(temporary_cstring_as_ptr)] #![allow(unknown_lints)] #![allow(unused_labels)] @@ -67,6 +68,7 @@ #![warn(clippy::stutter)] #![warn(clippy::to_string_in_display)] #![warn(clippy::zero_width_space)] +#![warn(clippy::clone_double_ref)] #![warn(clippy::drop_bounds)] #![warn(clippy::for_loop_over_option)] #![warn(clippy::for_loop_over_result)] diff --git a/src/tools/clippy/tests/ui/rename.stderr b/src/tools/clippy/tests/ui/rename.stderr index 27a0263292e..70d15408b9f 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:42:9 + --> $DIR/rename.rs:43:9 | LL | #![warn(clippy::almost_complete_letter_range)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::almost_complete_range` @@ -7,250 +7,256 @@ 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:43:9 + --> $DIR/rename.rs:44:9 | 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:44:9 + --> $DIR/rename.rs:45:9 | 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:45:9 + --> $DIR/rename.rs:46:9 | 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:46:9 + --> $DIR/rename.rs:47:9 | 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:47:9 + --> $DIR/rename.rs:48:9 | 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:48:9 + --> $DIR/rename.rs:49:9 | 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:49:9 + --> $DIR/rename.rs:50:9 | 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:50:9 + --> $DIR/rename.rs:51:9 | 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:51:9 + --> $DIR/rename.rs:52:9 | 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:52:9 + --> $DIR/rename.rs:53:9 | 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:53:9 + --> $DIR/rename.rs:54:9 | 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:54:9 + --> $DIR/rename.rs:55:9 | 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:55:9 + --> $DIR/rename.rs:56:9 | 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:56:9 + --> $DIR/rename.rs:57:9 | 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:57:9 + --> $DIR/rename.rs:58:9 | 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:58:9 + --> $DIR/rename.rs:59:9 | 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:59:9 + --> $DIR/rename.rs:60:9 | 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:60:9 + --> $DIR/rename.rs:61:9 | 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:61:9 + --> $DIR/rename.rs:62:9 | 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:62:9 + --> $DIR/rename.rs:63:9 | 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:63:9 + --> $DIR/rename.rs:64:9 | 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:64:9 + --> $DIR/rename.rs:65:9 | 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:65:9 + --> $DIR/rename.rs:66:9 | 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:66:9 + --> $DIR/rename.rs:67:9 | 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:67:9 + --> $DIR/rename.rs:68:9 | 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:68:9 + --> $DIR/rename.rs:69:9 | 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:69:9 + --> $DIR/rename.rs:70:9 | 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:71:9 + | +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:70:9 + --> $DIR/rename.rs:72:9 | LL | #![warn(clippy::drop_bounds)] | ^^^^^^^^^^^^^^^^^^^ help: use the new name: `drop_bounds` error: lint `clippy::for_loop_over_option` has been renamed to `for_loops_over_fallibles` - --> $DIR/rename.rs:71:9 + --> $DIR/rename.rs:73:9 | 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:72:9 + --> $DIR/rename.rs:74:9 | 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:73:9 + --> $DIR/rename.rs:75:9 | 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:74:9 + --> $DIR/rename.rs:76:9 | 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:75:9 + --> $DIR/rename.rs:77:9 | 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:76:9 + --> $DIR/rename.rs:78:9 | 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:77:9 + --> $DIR/rename.rs:79:9 | 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:78:9 + --> $DIR/rename.rs:80:9 | 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:79:9 + --> $DIR/rename.rs:81:9 | 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:80:9 + --> $DIR/rename.rs:82:9 | 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:81:9 + --> $DIR/rename.rs:83:9 | 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:82:9 + --> $DIR/rename.rs:84:9 | 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:83:9 + --> $DIR/rename.rs:85:9 | LL | #![warn(clippy::unused_label)] | ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unused_labels` -error: aborting due to 42 previous errors +error: aborting due to 43 previous errors diff --git a/src/tools/clippy/tests/ui/unnecessary_clone.rs b/src/tools/clippy/tests/ui/unnecessary_clone.rs index 8b1629b19a7..7ceed3c75fd 100644 --- a/src/tools/clippy/tests/ui/unnecessary_clone.rs +++ b/src/tools/clippy/tests/ui/unnecessary_clone.rs @@ -42,14 +42,6 @@ fn clone_on_copy_generic(t: T) { Some(t).clone(); } -fn clone_on_double_ref() { - let x = vec![1]; - let y = &&x; - let z: &Vec<_> = y.clone(); - - println!("{:p} {:p}", *y, z); -} - mod many_derefs { struct A; struct B; @@ -84,11 +76,6 @@ mod many_derefs { let _: E = a.clone(); let _: E = *****a; } - - fn check(mut encoded: &[u8]) { - let _ = &mut encoded.clone(); - let _ = &encoded.clone(); - } } mod issue2076 { diff --git a/src/tools/clippy/tests/ui/unnecessary_clone.stderr b/src/tools/clippy/tests/ui/unnecessary_clone.stderr index 6022d9fa4c5..5686ab6b453 100644 --- a/src/tools/clippy/tests/ui/unnecessary_clone.stderr +++ b/src/tools/clippy/tests/ui/unnecessary_clone.stderr @@ -44,63 +44,17 @@ error: using `clone` on type `Option` which implements the `Copy` trait LL | Some(t).clone(); | ^^^^^^^^^^^^^^^ help: try removing the `clone` call: `Some(t)` -error: using `clone` on a double-reference; this will copy the reference of type `&Vec` instead of cloning the inner type - --> $DIR/unnecessary_clone.rs:48:22 - | -LL | let z: &Vec<_> = y.clone(); - | ^^^^^^^^^ - | - = note: `#[deny(clippy::clone_double_ref)]` on by default -help: try dereferencing it - | -LL | let z: &Vec<_> = &(*y).clone(); - | ~~~~~~~~~~~~~ -help: or try being explicit if you are sure, that you want to clone a reference - | -LL | let z: &Vec<_> = <&Vec>::clone(y); - | ~~~~~~~~~~~~~~~~~~~~~ - error: using `clone` on type `E` which implements the `Copy` trait - --> $DIR/unnecessary_clone.rs:84:20 + --> $DIR/unnecessary_clone.rs:76:20 | LL | let _: E = a.clone(); | ^^^^^^^^^ help: try dereferencing it: `*****a` -error: using `clone` on a double-reference; this will copy the reference of type `&[u8]` instead of cloning the inner type - --> $DIR/unnecessary_clone.rs:89:22 - | -LL | let _ = &mut encoded.clone(); - | ^^^^^^^^^^^^^^^ - | -help: try dereferencing it - | -LL | let _ = &mut &(*encoded).clone(); - | ~~~~~~~~~~~~~~~~~~~ -help: or try being explicit if you are sure, that you want to clone a reference - | -LL | let _ = &mut <&[u8]>::clone(encoded); - | ~~~~~~~~~~~~~~~~~~~~~~~ - -error: using `clone` on a double-reference; this will copy the reference of type `&[u8]` instead of cloning the inner type - --> $DIR/unnecessary_clone.rs:90:18 - | -LL | let _ = &encoded.clone(); - | ^^^^^^^^^^^^^^^ - | -help: try dereferencing it - | -LL | let _ = &&(*encoded).clone(); - | ~~~~~~~~~~~~~~~~~~~ -help: or try being explicit if you are sure, that you want to clone a reference - | -LL | let _ = &<&[u8]>::clone(encoded); - | ~~~~~~~~~~~~~~~~~~~~~~~ - error: using `.clone()` on a ref-counted pointer - --> $DIR/unnecessary_clone.rs:108:14 + --> $DIR/unnecessary_clone.rs:95:14 | LL | Some(try_opt!(Some(rc)).clone()) | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `Rc::::clone(&try_opt!(Some(rc)))` -error: aborting due to 12 previous errors +error: aborting due to 9 previous errors diff --git a/tests/ui/lint/noop-method-call.rs b/tests/ui/lint/noop-method-call.rs index 89b29663595..dbcf2a5131b 100644 --- a/tests/ui/lint/noop-method-call.rs +++ b/tests/ui/lint/noop-method-call.rs @@ -19,18 +19,17 @@ fn main() { let clone_type_ref = &CloneType(1u32); let clone_type_ref_clone: CloneType = clone_type_ref.clone(); - // Calling clone on a double reference doesn't warn since the method call itself - // peels the outer reference off let clone_type_ref = &&CloneType(1u32); let clone_type_ref_clone: &CloneType = clone_type_ref.clone(); + //~^ WARNING using `.clone()` on a double reference, which returns `&CloneType` let non_deref_type = &PlainType(1u32); let non_deref_type_deref: &PlainType = non_deref_type.deref(); //~^ WARNING call to `.deref()` on a reference in this situation does nothing - // Dereferencing a &&T does not warn since it has collapsed the double reference let non_deref_type = &&PlainType(1u32); let non_deref_type_deref: &PlainType = non_deref_type.deref(); + //~^ WARNING using `.deref()` on a double reference, which returns `&PlainType` let non_borrow_type = &PlainType(1u32); let non_borrow_type_borrow: &PlainType = non_borrow_type.borrow(); @@ -41,7 +40,8 @@ fn main() { let non_borrow_type_borrow: &PlainType = non_borrow_type.borrow(); let xs = ["a", "b", "c"]; - let _v: Vec<&str> = xs.iter().map(|x| x.clone()).collect(); // ok, but could use `*x` instead + let _v: Vec<&str> = xs.iter().map(|x| x.clone()).collect(); // could use `*x` instead + //~^ WARNING using `.clone()` on a double reference, which returns `&str` } fn generic(non_clone_type: &PlainType) { diff --git a/tests/ui/lint/noop-method-call.stderr b/tests/ui/lint/noop-method-call.stderr index 6a904d01abc..37cd1a0fc18 100644 --- a/tests/ui/lint/noop-method-call.stderr +++ b/tests/ui/lint/noop-method-call.stderr @@ -11,22 +11,42 @@ note: the lint level is defined here LL | #![warn(noop_method_call)] | ^^^^^^^^^^^^^^^^ +warning: using `.clone()` on a double reference, which returns `&CloneType` instead of cloning the inner type + --> $DIR/noop-method-call.rs:23:63 + | +LL | let clone_type_ref_clone: &CloneType = clone_type_ref.clone(); + | ^^^^^^^^ + | + = note: `#[warn(suspicious_double_ref_op)]` on by default + warning: call to `.deref()` on a reference in this situation does nothing - --> $DIR/noop-method-call.rs:28:63 + --> $DIR/noop-method-call.rs:27:63 | LL | let non_deref_type_deref: &PlainType = non_deref_type.deref(); | ^^^^^^^^ unnecessary method call | = note: the type `&PlainType` which `deref` is being called on is the same as the type returned from `deref`, so the method call does not do anything and can be removed +warning: using `.deref()` on a double reference, which returns `&PlainType` instead of dereferencing the inner type + --> $DIR/noop-method-call.rs:31:63 + | +LL | let non_deref_type_deref: &PlainType = non_deref_type.deref(); + | ^^^^^^^^ + warning: call to `.borrow()` on a reference in this situation does nothing - --> $DIR/noop-method-call.rs:36:66 + --> $DIR/noop-method-call.rs:35:66 | LL | let non_borrow_type_borrow: &PlainType = non_borrow_type.borrow(); | ^^^^^^^^^ unnecessary method call | = note: the type `&PlainType` which `borrow` is being called on is the same as the type returned from `borrow`, so the method call does not do anything and can be removed +warning: using `.clone()` on a double reference, which returns `&str` instead of cloning the inner type + --> $DIR/noop-method-call.rs:43:44 + | +LL | let _v: Vec<&str> = xs.iter().map(|x| x.clone()).collect(); // could use `*x` instead + | ^^^^^^^^ + warning: call to `.clone()` on a reference in this situation does nothing --> $DIR/noop-method-call.rs:48:19 | @@ -43,5 +63,5 @@ LL | non_clone_type.clone(); | = note: the type `&PlainType` which `clone` is being called on is the same as the type returned from `clone`, so the method call does not do anything and can be removed -warning: 5 warnings emitted +warning: 8 warnings emitted diff --git a/tests/ui/lint/suspicious-double-ref-op.rs b/tests/ui/lint/suspicious-double-ref-op.rs new file mode 100644 index 00000000000..b9bcd31c2a8 --- /dev/null +++ b/tests/ui/lint/suspicious-double-ref-op.rs @@ -0,0 +1,30 @@ +#![feature(lazy_cell)] +#![deny(suspicious_double_ref_op, noop_method_call)] + +pub fn clone_on_double_ref() { + let x = vec![1]; + let y = &&x; + let z: &Vec<_> = y.clone(); + //~^ ERROR using `.clone()` on a double reference, which returns `&Vec` + + println!("{:p} {:p}", *y, z); +} + +use std::sync::LazyLock; + +pub static STRS: LazyLock<&str> = LazyLock::new(|| "First"); + +// https://github.com/rust-lang/rust-clippy/issues/9272 +fn rust_clippy_issue_9272() { + let str = STRS.clone(); + println!("{str}") +} + +fn check(mut encoded: &[u8]) { + let _ = &mut encoded.clone(); + //~^ ERROR call to `.clone()` on a reference in this situation does nothing + let _ = &encoded.clone(); + //~^ ERROR call to `.clone()` on a reference in this situation does nothing +} + +fn main() {} diff --git a/tests/ui/lint/suspicious-double-ref-op.stderr b/tests/ui/lint/suspicious-double-ref-op.stderr new file mode 100644 index 00000000000..d15487ca238 --- /dev/null +++ b/tests/ui/lint/suspicious-double-ref-op.stderr @@ -0,0 +1,35 @@ +error: using `.clone()` on a double reference, which returns `&Vec` instead of cloning the inner type + --> $DIR/suspicious-double-ref-op.rs:7:23 + | +LL | let z: &Vec<_> = y.clone(); + | ^^^^^^^^ + | +note: the lint level is defined here + --> $DIR/suspicious-double-ref-op.rs:2:9 + | +LL | #![deny(suspicious_double_ref_op, noop_method_call)] + | ^^^^^^^^^^^^^^^^^^^^^^^^ + +error: call to `.clone()` on a reference in this situation does nothing + --> $DIR/suspicious-double-ref-op.rs:24:25 + | +LL | let _ = &mut encoded.clone(); + | ^^^^^^^^ unnecessary method call + | + = note: the type `&[u8]` which `clone` is being called on is the same as the type returned from `clone`, so the method call does not do anything and can be removed +note: the lint level is defined here + --> $DIR/suspicious-double-ref-op.rs:2:35 + | +LL | #![deny(suspicious_double_ref_op, noop_method_call)] + | ^^^^^^^^^^^^^^^^ + +error: call to `.clone()` on a reference in this situation does nothing + --> $DIR/suspicious-double-ref-op.rs:26:21 + | +LL | let _ = &encoded.clone(); + | ^^^^^^^^ unnecessary method call + | + = note: the type `&[u8]` which `clone` is being called on is the same as the type returned from `clone`, so the method call does not do anything and can be removed + +error: aborting due to 3 previous errors +