Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

When encountering <&T as Clone>::clone(x) because T: Clone, suggest #[derive(Clone)] #121471

Merged
merged 1 commit into from
Feb 23, 2024
Merged

When encountering <&T as Clone>::clone(x) because T: Clone, suggest #[derive(Clone)] #121471

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions compiler/rustc_lint/messages.ftl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -429,6 +429,7 @@ lint_non_upper_case_global = {$sort} `{$name}` should have an upper case name
lint_noop_method_call = call to `.{$method}()` on a reference in this situation does nothing
.suggestion = remove this redundant call
.note = the type `{$orig_ty}` does not implement `{$trait_}`, so calling `{$method}` on `&{$orig_ty}` copies the reference, which does not do anything and can be removed
.derive_suggestion = if you meant to clone `{$orig_ty}`, implement `Clone` for it
lint_only_cast_u8_to_char = only `u8` can be cast into `char`
.suggestion = use a `char` literal instead
Expand Down
6 changes: 6 additions & 0 deletions compiler/rustc_lint/src/lints.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1314,6 +1314,12 @@ pub struct NoopMethodCallDiag<'a> {
pub trait_: Symbol,
#[suggestion(code = "", applicability = "machine-applicable")]
pub label: Span,
#[suggestion(
lint_derive_suggestion,
code = "#[derive(Clone)]\n",
applicability = "maybe-incorrect"
)]
pub suggest_derive: Option<Span>,
}

#[derive(LintDiagnostic)]
Expand Down
12 changes: 11 additions & 1 deletion compiler/rustc_lint/src/noop_method_call.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -121,10 +121,20 @@ impl<'tcx> LateLintPass<'tcx> for NoopMethodCall {
let orig_ty = expr_ty.peel_refs();

if receiver_ty == expr_ty {
let suggest_derive = match orig_ty.kind() {
ty::Adt(def, _) => Some(cx.tcx.def_span(def.did()).shrink_to_lo()),
_ => None,
};
cx.emit_span_lint(
NOOP_METHOD_CALL,
span,
NoopMethodCallDiag { method: call.ident.name, orig_ty, trait_, label: span },
NoopMethodCallDiag {
method: call.ident.name,
orig_ty,
trait_,
label: span,
suggest_derive,
},
);
} else {
match name {
Expand Down
64 changes: 0 additions & 64 deletions tests/ui/lint/noop-method-call.fixed
View file
Open in desktop

This file was deleted.

1 change: 0 additions & 1 deletion tests/ui/lint/noop-method-call.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,4 @@
//@ check-pass
//@ run-rustfix

#![feature(rustc_attrs)]
#![allow(unused)]
Expand Down
74 changes: 62 additions & 12 deletions tests/ui/lint/noop-method-call.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
warning: call to `.clone()` on a reference in this situation does nothing
--> $DIR/noop-method-call.rs:16:25
--> $DIR/noop-method-call.rs:15:25
|
LL | let _ = &mut encoded.clone();
| ^^^^^^^^ help: remove this redundant call
Expand All @@ -8,52 +8,102 @@ LL | let _ = &mut encoded.clone();
= note: `#[warn(noop_method_call)]` on by default

warning: call to `.clone()` on a reference in this situation does nothing
--> $DIR/noop-method-call.rs:18:21
--> $DIR/noop-method-call.rs:17:21
|
LL | let _ = &encoded.clone();
| ^^^^^^^^ help: remove this redundant call
|
= note: the type `[u8]` does not implement `Clone`, so calling `clone` on `&[u8]` copies the reference, which does not do anything and can be removed

warning: call to `.clone()` on a reference in this situation does nothing
--> $DIR/noop-method-call.rs:24:71
--> $DIR/noop-method-call.rs:23:71
|
LL | let non_clone_type_ref_clone: &PlainType<u32> = non_clone_type_ref.clone();
| ^^^^^^^^ help: remove this redundant call
| ^^^^^^^^
|
= note: the type `PlainType<u32>` does not implement `Clone`, so calling `clone` on `&PlainType<u32>` copies the reference, which does not do anything and can be removed
help: remove this redundant call
|
LL - let non_clone_type_ref_clone: &PlainType<u32> = non_clone_type_ref.clone();
LL + let non_clone_type_ref_clone: &PlainType<u32> = non_clone_type_ref;
|
help: if you meant to clone `PlainType<u32>`, implement `Clone` for it
|
LL + #[derive(Clone)]
LL | struct PlainType<T>(T);
|

warning: call to `.deref()` on a reference in this situation does nothing
--> $DIR/noop-method-call.rs:32:63
--> $DIR/noop-method-call.rs:31:63
|
LL | let non_deref_type_deref: &PlainType<u32> = non_deref_type.deref();
| ^^^^^^^^ help: remove this redundant call
| ^^^^^^^^
|
= note: the type `PlainType<u32>` does not implement `Deref`, so calling `deref` on `&PlainType<u32>` copies the reference, which does not do anything and can be removed
help: remove this redundant call
|
LL - let non_deref_type_deref: &PlainType<u32> = non_deref_type.deref();
LL + let non_deref_type_deref: &PlainType<u32> = non_deref_type;
|
help: if you meant to clone `PlainType<u32>`, implement `Clone` for it
|
LL + #[derive(Clone)]
LL | struct PlainType<T>(T);
|

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<u32> = non_borrow_type.borrow();
| ^^^^^^^^^ help: remove this redundant call
| ^^^^^^^^^
|
= note: the type `PlainType<u32>` does not implement `Borrow`, so calling `borrow` on `&PlainType<u32>` copies the reference, which does not do anything and can be removed
help: remove this redundant call
|
LL - let non_borrow_type_borrow: &PlainType<u32> = non_borrow_type.borrow();
LL + let non_borrow_type_borrow: &PlainType<u32> = non_borrow_type;
|
help: if you meant to clone `PlainType<u32>`, implement `Clone` for it
|
LL + #[derive(Clone)]
LL | struct PlainType<T>(T);
|

warning: call to `.clone()` on a reference in this situation does nothing
--> $DIR/noop-method-call.rs:45:19
--> $DIR/noop-method-call.rs:44:19
|
LL | non_clone_type.clone();
| ^^^^^^^^ help: remove this redundant call
| ^^^^^^^^
|
= note: the type `PlainType<T>` does not implement `Clone`, so calling `clone` on `&PlainType<T>` copies the reference, which does not do anything and can be removed
help: remove this redundant call
|
LL - non_clone_type.clone();
LL + non_clone_type;
|
help: if you meant to clone `PlainType<T>`, implement `Clone` for it
|
LL + #[derive(Clone)]
LL | struct PlainType<T>(T);
|

warning: call to `.clone()` on a reference in this situation does nothing
--> $DIR/noop-method-call.rs:50:19
--> $DIR/noop-method-call.rs:49:19
|
LL | non_clone_type.clone();
| ^^^^^^^^ help: remove this redundant call
| ^^^^^^^^
|
= note: the type `PlainType<u32>` does not implement `Clone`, so calling `clone` on `&PlainType<u32>` copies the reference, which does not do anything and can be removed
help: remove this redundant call
|
LL - non_clone_type.clone();
LL + non_clone_type;
|
help: if you meant to clone `PlainType<u32>`, implement `Clone` for it
|
LL + #[derive(Clone)]
LL | struct PlainType<T>(T);
|

warning: 7 warnings emitted

Loading