diff --git a/compiler/rustc_error_codes/src/error_codes/E0404.md b/compiler/rustc_error_codes/src/error_codes/E0404.md
index 1360cc99afcc4..d6fa51e618c4c 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0404.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0404.md
@@ -8,14 +8,15 @@ struct Foo;
struct Bar;
impl Foo for Bar {} // error: `Foo` is not a trait
+fn baz<T: Foo>(t: T) {} // error: `Foo` is not a trait
```
Another erroneous code example:
```compile_fail,E0404
-struct Foo;
+type Foo = Iterator<Item=String>;
-fn bar<T: Foo>(t: T) {} // error: `Foo` is not a trait
+fn bar<T: Foo>(t: T) {} // error: `Foo` is a type alias
```
Please verify that the trait's name was not misspelled or that the right
@@ -30,14 +31,27 @@ struct Bar;
impl Foo for Bar { // ok!
// functions implementation
}
+
+fn baz<T: Foo>(t: T) {} // ok!
```
-or:
+Alternatively, you could introduce a new trait with your desired restrictions
+as a super trait:
```
-trait Foo {
- // some functions
-}
+# trait Foo {}
+# struct Bar;
+# impl Foo for Bar {}
+trait Qux: Foo {} // Anything that implements Qux also needs to implement Foo
+fn baz<T: Qux>(t: T) {} // also ok!
+```
+
+Finally, if you are on nightly and want to use a trait alias
+instead of a type alias, you should use `#![feature(trait_alias)]`:
+
+```
+#![feature(trait_alias)]
+trait Foo = Iterator<Item=String>;
fn bar<T: Foo>(t: T) {} // ok!
```
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index c63edf365a1aa..70b019e8468e7 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -3,6 +3,7 @@
// from live codes are live, and everything else is dead.
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_hir::def::{CtorOf, DefKind, Res};
use rustc_hir::def_id::{DefId, LOCAL_CRATE};
@@ -15,7 +16,7 @@ use rustc_middle::middle::privacy;
use rustc_middle::ty::{self, DefIdTree, TyCtxt};
use rustc_session::lint;
-use rustc_span::symbol::{sym, Symbol};
+use rustc_span::symbol::{sym, Ident, Symbol};
// Any local node that may call something in its body block should be
// explored. For example, if it's a live Node::Item that is a
@@ -505,6 +506,13 @@ fn find_live<'tcx>(
symbol_visitor.live_symbols
}
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+enum ExtraNote {
+ /// Use this to provide some examples in the diagnostic of potential other purposes for a value
+ /// or field that is dead code
+ OtherPurposeExamples,
+}
+
struct DeadVisitor<'tcx> {
tcx: TyCtxt<'tcx>,
live_symbols: FxHashSet<hir::HirId>,
@@ -570,14 +578,42 @@ impl DeadVisitor<'tcx> {
&mut self,
id: hir::HirId,
span: rustc_span::Span,
- name: Symbol,
+ name: Ident,
participle: &str,
+ extra_note: Option<ExtraNote>,
) {
if !name.as_str().starts_with('_') {
self.tcx.struct_span_lint_hir(lint::builtin::DEAD_CODE, id, span, |lint| {
let def_id = self.tcx.hir().local_def_id(id);
let descr = self.tcx.def_kind(def_id).descr(def_id.to_def_id());
- lint.build(&format!("{} is never {}: `{}`", descr, participle, name)).emit()
+
+ let prefixed = vec![(name.span, format!("_{}", name))];
+
+ let mut diag =
+ lint.build(&format!("{} is never {}: `{}`", descr, participle, name));
+
+ diag.multipart_suggestion(
+ "if this is intentional, prefix it with an underscore",
+ prefixed,
+ Applicability::MachineApplicable,
+ );
+
+ let mut note = format!(
+ "the leading underscore signals that this {} serves some other \
+ purpose even if it isn't used in a way that we can detect.",
+ descr,
+ );
+ if matches!(extra_note, Some(ExtraNote::OtherPurposeExamples)) {
+ note += " (e.g. for its effect when dropped or in foreign code)";
+ }
+
+ diag.note(¬e);
+
+ // Force the note we added to the front, before any other subdiagnostics
+ // added in lint.build(...)
+ diag.children.rotate_right(1);
+
+ diag.emit()
});
}
}
@@ -623,7 +659,7 @@ impl Visitor<'tcx> for DeadVisitor<'tcx> {
hir::ItemKind::Struct(..) => "constructed", // Issue #52325
_ => "used",
};
- self.warn_dead_code(item.hir_id(), span, item.ident.name, participle);
+ self.warn_dead_code(item.hir_id(), span, item.ident, participle, None);
} else {
// Only continue if we didn't warn
intravisit::walk_item(self, item);
@@ -637,7 +673,7 @@ impl Visitor<'tcx> for DeadVisitor<'tcx> {
id: hir::HirId,
) {
if self.should_warn_about_variant(&variant) {
- self.warn_dead_code(variant.id, variant.span, variant.ident.name, "constructed");
+ self.warn_dead_code(variant.id, variant.span, variant.ident, "constructed", None);
} else {
intravisit::walk_variant(self, variant, g, id);
}
@@ -645,14 +681,20 @@ impl Visitor<'tcx> for DeadVisitor<'tcx> {
fn visit_foreign_item(&mut self, fi: &'tcx hir::ForeignItem<'tcx>) {
if self.should_warn_about_foreign_item(fi) {
- self.warn_dead_code(fi.hir_id(), fi.span, fi.ident.name, "used");
+ self.warn_dead_code(fi.hir_id(), fi.span, fi.ident, "used", None);
}
intravisit::walk_foreign_item(self, fi);
}
fn visit_field_def(&mut self, field: &'tcx hir::FieldDef<'tcx>) {
if self.should_warn_about_field(&field) {
- self.warn_dead_code(field.hir_id, field.span, field.ident.name, "read");
+ self.warn_dead_code(
+ field.hir_id,
+ field.span,
+ field.ident,
+ "read",
+ Some(ExtraNote::OtherPurposeExamples),
+ );
}
intravisit::walk_field_def(self, field);
}
@@ -664,8 +706,9 @@ impl Visitor<'tcx> for DeadVisitor<'tcx> {
self.warn_dead_code(
impl_item.hir_id(),
impl_item.span,
- impl_item.ident.name,
+ impl_item.ident,
"used",
+ None,
);
}
self.visit_nested_body(body_id)
@@ -683,7 +726,7 @@ impl Visitor<'tcx> for DeadVisitor<'tcx> {
} else {
impl_item.ident.span
};
- self.warn_dead_code(impl_item.hir_id(), span, impl_item.ident.name, "used");
+ self.warn_dead_code(impl_item.hir_id(), span, impl_item.ident, "used", None);
}
self.visit_nested_body(body_id)
}
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 6fae6921fc9b2..e33c374f562e2 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -930,7 +930,14 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
let msg = "you might have meant to use `#![feature(trait_alias)]` instead of a \
`type` alias";
if let Some(span) = self.def_span(def_id) {
- err.span_help(span, msg);
+ if let Ok(snip) = self.r.session.source_map().span_to_snippet(span) {
+ // The span contains a type alias so we should be able to
+ // replace `type` with `trait`.
+ let snip = snip.replacen("type", "trait", 1);
+ err.span_suggestion(span, msg, snip, Applicability::MaybeIncorrect);
+ } else {
+ err.span_help(span, msg);
+ }
} else {
err.help(msg);
}
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index b6b349e4a803d..b683626bbd64d 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -75,19 +75,21 @@ impl_stable_hash_via_hash!(OptLevel);
/// This is what the `LtoCli` values get mapped to after resolving defaults and
/// and taking other command line options into account.
+///
+/// Note that linker plugin-based LTO is a different mechanism entirely.
#[derive(Clone, PartialEq)]
pub enum Lto {
- /// Don't do any LTO whatsoever
+ /// Don't do any LTO whatsoever.
No,
- /// Do a full crate graph LTO with ThinLTO
+ /// Do a full-crate-graph (inter-crate) LTO with ThinLTO.
Thin,
- /// Do a local graph LTO with ThinLTO (only relevant for multiple codegen
- /// units).
+ /// Do a local ThinLTO (intra-crate, over the CodeGen Units of the local crate only). This is
+ /// only relevant if multiple CGUs are used.
ThinLocal,
- /// Do a full crate graph LTO with "fat" LTO
+ /// Do a full-crate-graph (inter-crate) LTO with "fat" LTO.
Fat,
}
diff --git a/src/test/ui/associated-consts/associated-const-dead-code.stderr b/src/test/ui/associated-consts/associated-const-dead-code.stderr
index 9b6bbb68a71f7..e9915ba9e96a5 100644
--- a/src/test/ui/associated-consts/associated-const-dead-code.stderr
+++ b/src/test/ui/associated-consts/associated-const-dead-code.stderr
@@ -2,8 +2,11 @@ error: associated constant is never used: `BAR`
--> $DIR/associated-const-dead-code.rs:6:5
|
LL | const BAR: u32 = 1;
- | ^^^^^^^^^^^^^^^^^^^
+ | ^^^^^^---^^^^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_BAR`
|
+ = note: the leading underscore signals that this associated constant serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/associated-const-dead-code.rs:1:9
|
diff --git a/src/test/ui/codemap_tests/two_files.stderr b/src/test/ui/codemap_tests/two_files.stderr
index de2ffc2e5dc1d..aff51ee9e2f54 100644
--- a/src/test/ui/codemap_tests/two_files.stderr
+++ b/src/test/ui/codemap_tests/two_files.stderr
@@ -5,10 +5,9 @@ LL | impl Bar for Baz { }
| ^^^ type aliases cannot be used as traits
|
help: you might have meant to use `#![feature(trait_alias)]` instead of a `type` alias
- --> $DIR/two_files_data.rs:5:1
|
-LL | type Bar = dyn Foo;
- | ^^^^^^^^^^^^^^^^^^^
+LL | trait Bar = dyn Foo;
+ |
error: aborting due to previous error
diff --git a/src/test/ui/derive-uninhabited-enum-38885.stderr b/src/test/ui/derive-uninhabited-enum-38885.stderr
index 72607629d3c10..ff8fb9953fb53 100644
--- a/src/test/ui/derive-uninhabited-enum-38885.stderr
+++ b/src/test/ui/derive-uninhabited-enum-38885.stderr
@@ -2,8 +2,11 @@ warning: variant is never constructed: `Void`
--> $DIR/derive-uninhabited-enum-38885.rs:13:5
|
LL | Void(Void),
- | ^^^^^^^^^^
+ | ----^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_Void`
|
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
= note: `-W dead-code` implied by `-W unused`
warning: 1 warning emitted
diff --git a/src/test/ui/issues/issue-37515.stderr b/src/test/ui/issues/issue-37515.stderr
index 204a39bc8e8e9..3223554a5b778 100644
--- a/src/test/ui/issues/issue-37515.stderr
+++ b/src/test/ui/issues/issue-37515.stderr
@@ -2,8 +2,11 @@ warning: type alias is never used: `Z`
--> $DIR/issue-37515.rs:5:1
|
LL | type Z = dyn for<'x> Send;
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^-^^^^^^^^^^^^^^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_Z`
|
+ = note: the leading underscore signals that this type alias serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/issue-37515.rs:3:9
|
diff --git a/src/test/ui/lint/dead-code/basic.stderr b/src/test/ui/lint/dead-code/basic.stderr
index f7b9b9c613ae0..8264d0736e03e 100644
--- a/src/test/ui/lint/dead-code/basic.stderr
+++ b/src/test/ui/lint/dead-code/basic.stderr
@@ -2,8 +2,9 @@ error: function is never used: `foo`
--> $DIR/basic.rs:4:4
|
LL | fn foo() {
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_foo`
|
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/basic.rs:1:9
|
diff --git a/src/test/ui/lint/dead-code/const-and-self.stderr b/src/test/ui/lint/dead-code/const-and-self.stderr
index c0e406189e8ab..e7233f386cc68 100644
--- a/src/test/ui/lint/dead-code/const-and-self.stderr
+++ b/src/test/ui/lint/dead-code/const-and-self.stderr
@@ -2,8 +2,9 @@ warning: variant is never constructed: `B`
--> $DIR/const-and-self.rs:33:5
|
LL | B,
- | ^
+ | ^ help: if this is intentional, prefix it with an underscore: `_B`
|
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/const-and-self.rs:3:9
|
@@ -14,7 +15,9 @@ warning: variant is never constructed: `C`
--> $DIR/const-and-self.rs:34:5
|
LL | C,
- | ^
+ | ^ help: if this is intentional, prefix it with an underscore: `_C`
+ |
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
warning: 2 warnings emitted
diff --git a/src/test/ui/lint/dead-code/drop-only-field-issue-81658.rs b/src/test/ui/lint/dead-code/drop-only-field-issue-81658.rs
new file mode 100644
index 0000000000000..d28b6430bc587
--- /dev/null
+++ b/src/test/ui/lint/dead-code/drop-only-field-issue-81658.rs
@@ -0,0 +1,42 @@
+//! The field `guard` is never used directly, but it is still useful for its side effect when
+//! dropped. Since rustc doesn't consider a `Drop` impl as a use, we want to make sure we at least
+//! produce a helpful diagnostic that points the user to what they can do if they indeed intended to
+//! have a field that is only used for its `Drop` side effect.
+//!
+//! Issue: https://github.com/rust-lang/rust/issues/81658
+
+#![deny(dead_code)]
+
+use std::sync::{Mutex, MutexGuard};
+
+/// Holds a locked value until it is dropped
+pub struct Locked<'a, T> {
+ // Field is kept for its affect when dropped, but otherwise unused
+ guard: MutexGuard<'a, T>, //~ ERROR field is never read
+}
+
+impl<'a, T> Locked<'a, T> {
+ pub fn new(value: &'a Mutex<T>) -> Self {
+ Self {
+ guard: value.lock().unwrap(),
+ }
+ }
+}
+
+fn main() {
+ let items = Mutex::new(vec![1, 2, 3]);
+
+ // Hold a lock on items while doing something else
+ let result = {
+ // The lock will be released at the end of this scope
+ let _lock = Locked::new(&items);
+
+ do_something_else()
+ };
+
+ println!("{}", result);
+}
+
+fn do_something_else() -> i32 {
+ 1 + 1
+}
diff --git a/src/test/ui/lint/dead-code/drop-only-field-issue-81658.stderr b/src/test/ui/lint/dead-code/drop-only-field-issue-81658.stderr
new file mode 100644
index 0000000000000..f379a0941166f
--- /dev/null
+++ b/src/test/ui/lint/dead-code/drop-only-field-issue-81658.stderr
@@ -0,0 +1,17 @@
+error: field is never read: `guard`
+ --> $DIR/drop-only-field-issue-81658.rs:15:5
+ |
+LL | guard: MutexGuard<'a, T>,
+ | -----^^^^^^^^^^^^^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_guard`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
+note: the lint level is defined here
+ --> $DIR/drop-only-field-issue-81658.rs:8:9
+ |
+LL | #![deny(dead_code)]
+ | ^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/lint/dead-code/empty-unused-enum.stderr b/src/test/ui/lint/dead-code/empty-unused-enum.stderr
index ed9a7ccd14b21..5c06cd5a6a0b2 100644
--- a/src/test/ui/lint/dead-code/empty-unused-enum.stderr
+++ b/src/test/ui/lint/dead-code/empty-unused-enum.stderr
@@ -2,8 +2,9 @@ error: enum is never used: `E`
--> $DIR/empty-unused-enum.rs:3:6
|
LL | enum E {}
- | ^
+ | ^ help: if this is intentional, prefix it with an underscore: `_E`
|
+ = note: the leading underscore signals that this enum serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/empty-unused-enum.rs:1:9
|
diff --git a/src/test/ui/lint/dead-code/field-used-in-ffi-issue-81658.rs b/src/test/ui/lint/dead-code/field-used-in-ffi-issue-81658.rs
new file mode 100644
index 0000000000000..12eafe6ae4958
--- /dev/null
+++ b/src/test/ui/lint/dead-code/field-used-in-ffi-issue-81658.rs
@@ -0,0 +1,50 @@
+//! The field `items` is being "used" by FFI (implicitly through pointers). However, since rustc
+//! doesn't know how to detect that, we produce a message that says the field is unused. This can
+//! cause some confusion and we want to make sure our diagnostics help as much as they can.
+//!
+//! Issue: https://github.com/rust-lang/rust/issues/81658
+
+#![deny(dead_code)]
+
+/// A struct for holding on to data while it is being used in our FFI code
+pub struct FFIData<T> {
+ /// These values cannot be dropped while the pointers to each item
+ /// are still in use
+ items: Option<Vec<T>>, //~ ERROR field is never read
+}
+
+impl<T> FFIData<T> {
+ pub fn new() -> Self {
+ Self {items: None}
+ }
+
+ /// Load items into this type and return pointers to each item that can
+ /// be passed to FFI
+ pub fn load(&mut self, items: Vec<T>) -> Vec<*const T> {
+ let ptrs = items.iter().map(|item| item as *const _).collect();
+
+ self.items = Some(items);
+
+ ptrs
+ }
+}
+
+extern {
+ /// The FFI code that uses items
+ fn process_item(item: *const i32);
+}
+
+fn main() {
+ // Data cannot be dropped until the end of this scope or else the items
+ // will be dropped before they are processed
+ let mut data = FFIData::new();
+
+ let ptrs = data.load(vec![1, 2, 3, 4, 5]);
+
+ for ptr in ptrs {
+ // Safety: This pointer is valid as long as the arena is in scope
+ unsafe { process_item(ptr); }
+ }
+
+ // Items will be safely freed at the end of this scope
+}
diff --git a/src/test/ui/lint/dead-code/field-used-in-ffi-issue-81658.stderr b/src/test/ui/lint/dead-code/field-used-in-ffi-issue-81658.stderr
new file mode 100644
index 0000000000000..d6a247d98e292
--- /dev/null
+++ b/src/test/ui/lint/dead-code/field-used-in-ffi-issue-81658.stderr
@@ -0,0 +1,17 @@
+error: field is never read: `items`
+ --> $DIR/field-used-in-ffi-issue-81658.rs:13:5
+ |
+LL | items: Option<Vec<T>>,
+ | -----^^^^^^^^^^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_items`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
+note: the lint level is defined here
+ --> $DIR/field-used-in-ffi-issue-81658.rs:7:9
+ |
+LL | #![deny(dead_code)]
+ | ^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/lint/dead-code/impl-trait.stderr b/src/test/ui/lint/dead-code/impl-trait.stderr
index 09b6d08eb8fb8..fb18eb2819f76 100644
--- a/src/test/ui/lint/dead-code/impl-trait.stderr
+++ b/src/test/ui/lint/dead-code/impl-trait.stderr
@@ -2,8 +2,11 @@ error: type alias is never used: `Unused`
--> $DIR/impl-trait.rs:12:1
|
LL | type Unused = ();
- | ^^^^^^^^^^^^^^^^^
+ | ^^^^^------^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_Unused`
|
+ = note: the leading underscore signals that this type alias serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/impl-trait.rs:1:9
|
diff --git a/src/test/ui/lint/dead-code/lint-dead-code-1.stderr b/src/test/ui/lint/dead-code/lint-dead-code-1.stderr
index af97ea98b2b6d..15448448e1169 100644
--- a/src/test/ui/lint/dead-code/lint-dead-code-1.stderr
+++ b/src/test/ui/lint/dead-code/lint-dead-code-1.stderr
@@ -2,8 +2,9 @@ error: struct is never constructed: `Bar`
--> $DIR/lint-dead-code-1.rs:12:16
|
LL | pub struct Bar;
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_Bar`
|
+ = note: the leading underscore signals that this struct serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/lint-dead-code-1.rs:5:9
|
@@ -14,55 +15,77 @@ error: static is never used: `priv_static`
--> $DIR/lint-dead-code-1.rs:20:1
|
LL | static priv_static: isize = 0;
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^^^-----------^^^^^^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_priv_static`
+ |
+ = note: the leading underscore signals that this static serves some other purpose even if it isn't used in a way that we can detect.
error: constant is never used: `priv_const`
--> $DIR/lint-dead-code-1.rs:27:1
|
LL | const priv_const: isize = 0;
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^^----------^^^^^^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_priv_const`
+ |
+ = note: the leading underscore signals that this constant serves some other purpose even if it isn't used in a way that we can detect.
error: struct is never constructed: `PrivStruct`
--> $DIR/lint-dead-code-1.rs:35:8
|
LL | struct PrivStruct;
- | ^^^^^^^^^^
+ | ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_PrivStruct`
+ |
+ = note: the leading underscore signals that this struct serves some other purpose even if it isn't used in a way that we can detect.
error: enum is never used: `priv_enum`
--> $DIR/lint-dead-code-1.rs:64:6
|
LL | enum priv_enum { foo2, bar2 }
- | ^^^^^^^^^
+ | ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_priv_enum`
+ |
+ = note: the leading underscore signals that this enum serves some other purpose even if it isn't used in a way that we can detect.
error: variant is never constructed: `bar3`
--> $DIR/lint-dead-code-1.rs:67:5
|
LL | bar3
- | ^^^^
+ | ^^^^ help: if this is intentional, prefix it with an underscore: `_bar3`
+ |
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
error: function is never used: `priv_fn`
--> $DIR/lint-dead-code-1.rs:88:4
|
LL | fn priv_fn() {
- | ^^^^^^^
+ | ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_priv_fn`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: function is never used: `foo`
--> $DIR/lint-dead-code-1.rs:93:4
|
LL | fn foo() {
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_foo`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: function is never used: `bar`
--> $DIR/lint-dead-code-1.rs:98:4
|
LL | fn bar() {
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_bar`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: function is never used: `baz`
--> $DIR/lint-dead-code-1.rs:102:4
|
LL | fn baz() -> impl Copy {
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_baz`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: aborting due to 10 previous errors
diff --git a/src/test/ui/lint/dead-code/lint-dead-code-2.stderr b/src/test/ui/lint/dead-code/lint-dead-code-2.stderr
index b01ba57f98580..5e19c7d02ffd3 100644
--- a/src/test/ui/lint/dead-code/lint-dead-code-2.stderr
+++ b/src/test/ui/lint/dead-code/lint-dead-code-2.stderr
@@ -2,8 +2,9 @@ error: function is never used: `dead_fn`
--> $DIR/lint-dead-code-2.rs:22:4
|
LL | fn dead_fn() {}
- | ^^^^^^^
+ | ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_dead_fn`
|
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/lint-dead-code-2.rs:2:9
|
@@ -14,13 +15,17 @@ error: function is never used: `dead_fn2`
--> $DIR/lint-dead-code-2.rs:25:4
|
LL | fn dead_fn2() {}
- | ^^^^^^^^
+ | ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_dead_fn2`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: function is never used: `main`
--> $DIR/lint-dead-code-2.rs:38:4
|
LL | fn main() {
- | ^^^^
+ | ^^^^ help: if this is intentional, prefix it with an underscore: `_main`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: aborting due to 3 previous errors
diff --git a/src/test/ui/lint/dead-code/lint-dead-code-3.stderr b/src/test/ui/lint/dead-code/lint-dead-code-3.stderr
index cf8f01ea19f0c..d32fde5872d99 100644
--- a/src/test/ui/lint/dead-code/lint-dead-code-3.stderr
+++ b/src/test/ui/lint/dead-code/lint-dead-code-3.stderr
@@ -2,8 +2,9 @@ error: struct is never constructed: `Foo`
--> $DIR/lint-dead-code-3.rs:14:8
|
LL | struct Foo;
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_Foo`
|
+ = note: the leading underscore signals that this struct serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/lint-dead-code-3.rs:4:9
|
@@ -14,25 +15,35 @@ error: associated function is never used: `foo`
--> $DIR/lint-dead-code-3.rs:16:8
|
LL | fn foo(&self) {
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_foo`
+ |
+ = note: the leading underscore signals that this associated function serves some other purpose even if it isn't used in a way that we can detect.
error: function is never used: `bar`
--> $DIR/lint-dead-code-3.rs:21:4
|
LL | fn bar() {
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_bar`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: enum is never used: `c_void`
--> $DIR/lint-dead-code-3.rs:60:6
|
LL | enum c_void {}
- | ^^^^^^
+ | ^^^^^^ help: if this is intentional, prefix it with an underscore: `_c_void`
+ |
+ = note: the leading underscore signals that this enum serves some other purpose even if it isn't used in a way that we can detect.
error: function is never used: `free`
--> $DIR/lint-dead-code-3.rs:62:5
|
LL | fn free(p: *const c_void);
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^----^^^^^^^^^^^^^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_free`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: aborting due to 5 previous errors
diff --git a/src/test/ui/lint/dead-code/lint-dead-code-4.stderr b/src/test/ui/lint/dead-code/lint-dead-code-4.stderr
index 3905d1a06bdfe..2785faa29f5d9 100644
--- a/src/test/ui/lint/dead-code/lint-dead-code-4.stderr
+++ b/src/test/ui/lint/dead-code/lint-dead-code-4.stderr
@@ -2,8 +2,11 @@ error: field is never read: `b`
--> $DIR/lint-dead-code-4.rs:7:5
|
LL | b: bool,
- | ^^^^^^^
+ | -^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_b`
|
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
note: the lint level is defined here
--> $DIR/lint-dead-code-4.rs:3:9
|
@@ -14,59 +17,88 @@ error: variant is never constructed: `X`
--> $DIR/lint-dead-code-4.rs:15:5
|
LL | X,
- | ^
+ | ^ help: if this is intentional, prefix it with an underscore: `_X`
+ |
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
error: variant is never constructed: `Y`
--> $DIR/lint-dead-code-4.rs:16:5
|
-LL | / Y {
+LL | Y {
+ | ^ help: if this is intentional, prefix it with an underscore: `_Y`
+ | _____|
+ | |
LL | | a: String,
LL | | b: i32,
LL | | c: i32,
LL | | },
| |_____^
+ |
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
error: enum is never used: `ABC`
--> $DIR/lint-dead-code-4.rs:24:6
|
LL | enum ABC {
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_ABC`
+ |
+ = note: the leading underscore signals that this enum serves some other purpose even if it isn't used in a way that we can detect.
error: variant is never constructed: `I`
--> $DIR/lint-dead-code-4.rs:36:5
|
LL | I,
- | ^
+ | ^ help: if this is intentional, prefix it with an underscore: `_I`
+ |
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
error: field is never read: `b`
--> $DIR/lint-dead-code-4.rs:39:9
|
LL | b: i32,
- | ^^^^^^
+ | -^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_b`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: field is never read: `c`
--> $DIR/lint-dead-code-4.rs:40:9
|
LL | c: i32,
- | ^^^^^^
+ | -^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_c`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: variant is never constructed: `K`
--> $DIR/lint-dead-code-4.rs:42:5
|
LL | K
- | ^
+ | ^ help: if this is intentional, prefix it with an underscore: `_K`
+ |
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
error: field is never read: `x`
--> $DIR/lint-dead-code-4.rs:61:5
|
LL | x: usize,
- | ^^^^^^^^
+ | -^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_x`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: field is never read: `c`
--> $DIR/lint-dead-code-4.rs:63:5
|
LL | c: bool,
- | ^^^^^^^
+ | -^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_c`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: aborting due to 10 previous errors
diff --git a/src/test/ui/lint/dead-code/lint-dead-code-5.stderr b/src/test/ui/lint/dead-code/lint-dead-code-5.stderr
index 519add826273f..6375d98d35cb2 100644
--- a/src/test/ui/lint/dead-code/lint-dead-code-5.stderr
+++ b/src/test/ui/lint/dead-code/lint-dead-code-5.stderr
@@ -2,8 +2,9 @@ error: variant is never constructed: `Variant2`
--> $DIR/lint-dead-code-5.rs:6:5
|
LL | Variant2
- | ^^^^^^^^
+ | ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_Variant2`
|
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/lint-dead-code-5.rs:2:9
|
@@ -14,19 +15,29 @@ error: variant is never constructed: `Variant5`
--> $DIR/lint-dead-code-5.rs:13:5
|
LL | Variant5 { _x: isize },
- | ^^^^^^^^^^^^^^^^^^^^^^
+ | --------^^^^^^^^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_Variant5`
+ |
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
error: variant is never constructed: `Variant6`
--> $DIR/lint-dead-code-5.rs:14:5
|
LL | Variant6(isize),
- | ^^^^^^^^^^^^^^^
+ | --------^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_Variant6`
+ |
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
error: enum is never used: `Enum3`
--> $DIR/lint-dead-code-5.rs:35:6
|
LL | enum Enum3 {
- | ^^^^^
+ | ^^^^^ help: if this is intentional, prefix it with an underscore: `_Enum3`
+ |
+ = note: the leading underscore signals that this enum serves some other purpose even if it isn't used in a way that we can detect.
error: aborting due to 4 previous errors
diff --git a/src/test/ui/lint/dead-code/lint-dead-code-6.stderr b/src/test/ui/lint/dead-code/lint-dead-code-6.stderr
index 7dc60730d6aad..ef26fe54ab589 100644
--- a/src/test/ui/lint/dead-code/lint-dead-code-6.stderr
+++ b/src/test/ui/lint/dead-code/lint-dead-code-6.stderr
@@ -2,8 +2,9 @@ error: struct is never constructed: `UnusedStruct`
--> $DIR/lint-dead-code-6.rs:3:8
|
LL | struct UnusedStruct;
- | ^^^^^^^^^^^^
+ | ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_UnusedStruct`
|
+ = note: the leading underscore signals that this struct serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/lint-dead-code-6.rs:1:9
|
@@ -14,19 +15,25 @@ error: associated function is never used: `unused_impl_fn_1`
--> $DIR/lint-dead-code-6.rs:5:8
|
LL | fn unused_impl_fn_1() {
- | ^^^^^^^^^^^^^^^^
+ | ^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused_impl_fn_1`
+ |
+ = note: the leading underscore signals that this associated function serves some other purpose even if it isn't used in a way that we can detect.
error: associated function is never used: `unused_impl_fn_2`
--> $DIR/lint-dead-code-6.rs:9:8
|
LL | fn unused_impl_fn_2(var: i32) {
- | ^^^^^^^^^^^^^^^^
+ | ^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused_impl_fn_2`
+ |
+ = note: the leading underscore signals that this associated function serves some other purpose even if it isn't used in a way that we can detect.
error: associated function is never used: `unused_impl_fn_3`
--> $DIR/lint-dead-code-6.rs:13:8
|
LL | fn unused_impl_fn_3(
- | ^^^^^^^^^^^^^^^^
+ | ^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused_impl_fn_3`
+ |
+ = note: the leading underscore signals that this associated function serves some other purpose even if it isn't used in a way that we can detect.
error: aborting due to 4 previous errors
diff --git a/src/test/ui/lint/dead-code/newline-span.stderr b/src/test/ui/lint/dead-code/newline-span.stderr
index fd74405f2b648..5bd566be35e01 100644
--- a/src/test/ui/lint/dead-code/newline-span.stderr
+++ b/src/test/ui/lint/dead-code/newline-span.stderr
@@ -2,8 +2,9 @@ error: function is never used: `unused`
--> $DIR/newline-span.rs:3:4
|
LL | fn unused() {
- | ^^^^^^
+ | ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
|
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/newline-span.rs:1:9
|
@@ -14,13 +15,17 @@ error: function is never used: `unused2`
--> $DIR/newline-span.rs:7:4
|
LL | fn unused2(var: i32) {
- | ^^^^^^^
+ | ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused2`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: function is never used: `unused3`
--> $DIR/newline-span.rs:11:4
|
LL | fn unused3(
- | ^^^^^^^
+ | ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused3`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
error: aborting due to 3 previous errors
diff --git a/src/test/ui/lint/dead-code/type-alias.stderr b/src/test/ui/lint/dead-code/type-alias.stderr
index b2acd5d4213b3..1e7a030de3aa7 100644
--- a/src/test/ui/lint/dead-code/type-alias.stderr
+++ b/src/test/ui/lint/dead-code/type-alias.stderr
@@ -2,8 +2,11 @@ error: type alias is never used: `Unused`
--> $DIR/type-alias.rs:4:1
|
LL | type Unused = u8;
- | ^^^^^^^^^^^^^^^^^
+ | ^^^^^------^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_Unused`
|
+ = note: the leading underscore signals that this type alias serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/type-alias.rs:1:9
|
diff --git a/src/test/ui/lint/dead-code/unused-enum.stderr b/src/test/ui/lint/dead-code/unused-enum.stderr
index 9f368fdd2f816..d536479c800ae 100644
--- a/src/test/ui/lint/dead-code/unused-enum.stderr
+++ b/src/test/ui/lint/dead-code/unused-enum.stderr
@@ -2,8 +2,9 @@ error: struct is never constructed: `F`
--> $DIR/unused-enum.rs:3:8
|
LL | struct F;
- | ^
+ | ^ help: if this is intentional, prefix it with an underscore: `_F`
|
+ = note: the leading underscore signals that this struct serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/unused-enum.rs:1:9
|
@@ -15,13 +16,17 @@ error: struct is never constructed: `B`
--> $DIR/unused-enum.rs:4:8
|
LL | struct B;
- | ^
+ | ^ help: if this is intentional, prefix it with an underscore: `_B`
+ |
+ = note: the leading underscore signals that this struct serves some other purpose even if it isn't used in a way that we can detect.
error: enum is never used: `E`
--> $DIR/unused-enum.rs:6:6
|
LL | enum E {
- | ^
+ | ^ help: if this is intentional, prefix it with an underscore: `_E`
+ |
+ = note: the leading underscore signals that this enum serves some other purpose even if it isn't used in a way that we can detect.
error: aborting due to 3 previous errors
diff --git a/src/test/ui/lint/dead-code/unused-struct-variant.stderr b/src/test/ui/lint/dead-code/unused-struct-variant.stderr
index b93d6d4ac1866..394ced3e81001 100644
--- a/src/test/ui/lint/dead-code/unused-struct-variant.stderr
+++ b/src/test/ui/lint/dead-code/unused-struct-variant.stderr
@@ -2,8 +2,11 @@ error: variant is never constructed: `Bar`
--> $DIR/unused-struct-variant.rs:8:5
|
LL | Bar(B),
- | ^^^^^^
+ | ---^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_Bar`
|
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/unused-struct-variant.rs:1:9
|
diff --git a/src/test/ui/lint/dead-code/unused-variant.stderr b/src/test/ui/lint/dead-code/unused-variant.stderr
index a547f5af4b082..7dcb79d0490c1 100644
--- a/src/test/ui/lint/dead-code/unused-variant.stderr
+++ b/src/test/ui/lint/dead-code/unused-variant.stderr
@@ -2,8 +2,9 @@ error: variant is never constructed: `Variant1`
--> $DIR/unused-variant.rs:5:5
|
LL | Variant1,
- | ^^^^^^^^
+ | ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_Variant1`
|
+ = note: the leading underscore signals that this variant serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/unused-variant.rs:1:9
|
diff --git a/src/test/ui/lint/dead-code/with-core-crate.stderr b/src/test/ui/lint/dead-code/with-core-crate.stderr
index 2c63e60d67609..1bde434069ee7 100644
--- a/src/test/ui/lint/dead-code/with-core-crate.stderr
+++ b/src/test/ui/lint/dead-code/with-core-crate.stderr
@@ -2,8 +2,9 @@ error: function is never used: `foo`
--> $DIR/with-core-crate.rs:7:4
|
LL | fn foo() {
- | ^^^
+ | ^^^ help: if this is intentional, prefix it with an underscore: `_foo`
|
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/with-core-crate.rs:1:9
|
diff --git a/src/test/ui/lint/dead-code/write-only-field.stderr b/src/test/ui/lint/dead-code/write-only-field.stderr
index a191d22c8b94c..13a21bb1193de 100644
--- a/src/test/ui/lint/dead-code/write-only-field.stderr
+++ b/src/test/ui/lint/dead-code/write-only-field.stderr
@@ -2,8 +2,11 @@ error: field is never read: `f`
--> $DIR/write-only-field.rs:4:5
|
LL | f: i32,
- | ^^^^^^
+ | -^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_f`
|
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
note: the lint level is defined here
--> $DIR/write-only-field.rs:1:9
|
@@ -14,31 +17,51 @@ error: field is never read: `sub`
--> $DIR/write-only-field.rs:5:5
|
LL | sub: Sub,
- | ^^^^^^^^
+ | ---^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_sub`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: field is never read: `f`
--> $DIR/write-only-field.rs:9:5
|
LL | f: i32,
- | ^^^^^^
+ | -^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_f`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: field is never read: `y`
--> $DIR/write-only-field.rs:28:9
|
LL | y: bool,
- | ^^^^^^^
+ | -^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_y`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: field is never read: `u`
--> $DIR/write-only-field.rs:58:9
|
LL | u: u32,
- | ^^^^^^
+ | -^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_u`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: field is never read: `v`
--> $DIR/write-only-field.rs:59:9
|
LL | v: u32,
- | ^^^^^^
+ | -^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_v`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: aborting due to 6 previous errors
diff --git a/src/test/ui/lint/issue-17718-const-naming.stderr b/src/test/ui/lint/issue-17718-const-naming.stderr
index ce4ebcb5e3ef6..e880006e114c1 100644
--- a/src/test/ui/lint/issue-17718-const-naming.stderr
+++ b/src/test/ui/lint/issue-17718-const-naming.stderr
@@ -2,8 +2,11 @@ error: constant is never used: `foo`
--> $DIR/issue-17718-const-naming.rs:4:1
|
LL | const foo: isize = 3;
- | ^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^^---^^^^^^^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_foo`
|
+ = note: the leading underscore signals that this constant serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/issue-17718-const-naming.rs:2:9
|
diff --git a/src/test/ui/resolve/issue-3907.stderr b/src/test/ui/resolve/issue-3907.stderr
index 4d0b0af58a320..6fc61cae84339 100644
--- a/src/test/ui/resolve/issue-3907.stderr
+++ b/src/test/ui/resolve/issue-3907.stderr
@@ -5,10 +5,9 @@ LL | impl Foo for S {
| ^^^ type aliases cannot be used as traits
|
help: you might have meant to use `#![feature(trait_alias)]` instead of a `type` alias
- --> $DIR/issue-3907.rs:5:1
|
-LL | type Foo = dyn issue_3907::Foo;
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | trait Foo = dyn issue_3907::Foo;
+ |
help: consider importing this trait instead
|
LL | use issue_3907::Foo;
diff --git a/src/test/ui/resolve/issue-5035.stderr b/src/test/ui/resolve/issue-5035.stderr
index 41dff2fe54205..a8aa50b7c3ab2 100644
--- a/src/test/ui/resolve/issue-5035.stderr
+++ b/src/test/ui/resolve/issue-5035.stderr
@@ -11,16 +11,16 @@ LL | trait I {}
| ------- similarly named trait `I` defined here
LL | type K = dyn I;
LL | impl K for isize {}
- | ^
- | |
- | type aliases cannot be used as traits
- | help: a trait with a similar name exists: `I`
+ | ^ type aliases cannot be used as traits
|
help: you might have meant to use `#![feature(trait_alias)]` instead of a `type` alias
- --> $DIR/issue-5035.rs:2:1
|
-LL | type K = dyn I;
- | ^^^^^^^^^^^^^^^
+LL | trait K = dyn I;
+ |
+help: a trait with a similar name exists
+ |
+LL | impl I for isize {}
+ | ^
error: aborting due to 2 previous errors
diff --git a/src/test/ui/resolve/unboxed-closure-sugar-nonexistent-trait.stderr b/src/test/ui/resolve/unboxed-closure-sugar-nonexistent-trait.stderr
index 2974d08eb23b1..8addc0303fb91 100644
--- a/src/test/ui/resolve/unboxed-closure-sugar-nonexistent-trait.stderr
+++ b/src/test/ui/resolve/unboxed-closure-sugar-nonexistent-trait.stderr
@@ -11,10 +11,9 @@ LL | fn g<F:Typedef(isize) -> isize>(x: F) {}
| ^^^^^^^^^^^^^^^^^^^^^^^ type aliases cannot be used as traits
|
help: you might have meant to use `#![feature(trait_alias)]` instead of a `type` alias
- --> $DIR/unboxed-closure-sugar-nonexistent-trait.rs:4:1
|
-LL | type Typedef = isize;
- | ^^^^^^^^^^^^^^^^^^^^^
+LL | trait Typedef = isize;
+ |
error: aborting due to 2 previous errors
diff --git a/src/test/ui/span/macro-span-replacement.stderr b/src/test/ui/span/macro-span-replacement.stderr
index 45cf5f8688cd1..f94a9e30a3dfa 100644
--- a/src/test/ui/span/macro-span-replacement.stderr
+++ b/src/test/ui/span/macro-span-replacement.stderr
@@ -2,11 +2,14 @@ warning: struct is never constructed: `S`
--> $DIR/macro-span-replacement.rs:7:14
|
LL | $b $a;
- | ^
+ | --^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_S`
...
LL | m!(S struct);
| ------------- in this macro invocation
|
+ = note: the leading underscore signals that this struct serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/macro-span-replacement.rs:3:9
|
diff --git a/src/test/ui/span/unused-warning-point-at-identifier.stderr b/src/test/ui/span/unused-warning-point-at-identifier.stderr
index 6ef877da122f5..3bf342f197252 100644
--- a/src/test/ui/span/unused-warning-point-at-identifier.stderr
+++ b/src/test/ui/span/unused-warning-point-at-identifier.stderr
@@ -2,8 +2,9 @@ warning: enum is never used: `Enum`
--> $DIR/unused-warning-point-at-identifier.rs:5:6
|
LL | enum Enum {
- | ^^^^
+ | ^^^^ help: if this is intentional, prefix it with an underscore: `_Enum`
|
+ = note: the leading underscore signals that this enum serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/unused-warning-point-at-identifier.rs:3:9
|
@@ -15,19 +16,25 @@ warning: struct is never constructed: `Struct`
--> $DIR/unused-warning-point-at-identifier.rs:12:8
|
LL | struct Struct {
- | ^^^^^^
+ | ^^^^^^ help: if this is intentional, prefix it with an underscore: `_Struct`
+ |
+ = note: the leading underscore signals that this struct serves some other purpose even if it isn't used in a way that we can detect.
warning: function is never used: `func`
--> $DIR/unused-warning-point-at-identifier.rs:19:4
|
LL | fn func() -> usize {
- | ^^^^
+ | ^^^^ help: if this is intentional, prefix it with an underscore: `_func`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
warning: function is never used: `func_complete_span`
--> $DIR/unused-warning-point-at-identifier.rs:24:1
|
LL | func_complete_span()
- | ^^^^^^^^^^^^^^^^^^
+ | ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_func_complete_span`
+ |
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
warning: 4 warnings emitted
diff --git a/src/test/ui/test-attrs/test-warns-dead-code.stderr b/src/test/ui/test-attrs/test-warns-dead-code.stderr
index d3bcea2951364..e5a8dee6ccb68 100644
--- a/src/test/ui/test-attrs/test-warns-dead-code.stderr
+++ b/src/test/ui/test-attrs/test-warns-dead-code.stderr
@@ -2,8 +2,9 @@ error: function is never used: `dead`
--> $DIR/test-warns-dead-code.rs:5:4
|
LL | fn dead() {}
- | ^^^^
+ | ^^^^ help: if this is intentional, prefix it with an underscore: `_dead`
|
+ = note: the leading underscore signals that this function serves some other purpose even if it isn't used in a way that we can detect.
note: the lint level is defined here
--> $DIR/test-warns-dead-code.rs:3:9
|
diff --git a/src/test/ui/traits/alias/suggest-trait-alias-instead-of-type.fixed b/src/test/ui/traits/alias/suggest-trait-alias-instead-of-type.fixed
new file mode 100644
index 0000000000000..8a94abaeb0744
--- /dev/null
+++ b/src/test/ui/traits/alias/suggest-trait-alias-instead-of-type.fixed
@@ -0,0 +1,13 @@
+// Regression test of #43913.
+
+// run-rustfix
+
+#![feature(trait_alias)]
+#![allow(bare_trait_objects, dead_code)]
+
+trait Strings = Iterator<Item=String>;
+
+struct Struct<S: Strings>(S);
+//~^ ERROR: expected trait, found type alias `Strings`
+
+fn main() {}
diff --git a/src/test/ui/traits/alias/suggest-trait-alias-instead-of-type.rs b/src/test/ui/traits/alias/suggest-trait-alias-instead-of-type.rs
new file mode 100644
index 0000000000000..40c678c281f4c
--- /dev/null
+++ b/src/test/ui/traits/alias/suggest-trait-alias-instead-of-type.rs
@@ -0,0 +1,13 @@
+// Regression test of #43913.
+
+// run-rustfix
+
+#![feature(trait_alias)]
+#![allow(bare_trait_objects, dead_code)]
+
+type Strings = Iterator<Item=String>;
+
+struct Struct<S: Strings>(S);
+//~^ ERROR: expected trait, found type alias `Strings`
+
+fn main() {}
diff --git a/src/test/ui/traits/alias/suggest-trait-alias-instead-of-type.stderr b/src/test/ui/traits/alias/suggest-trait-alias-instead-of-type.stderr
new file mode 100644
index 0000000000000..6e03eeada499c
--- /dev/null
+++ b/src/test/ui/traits/alias/suggest-trait-alias-instead-of-type.stderr
@@ -0,0 +1,14 @@
+error[E0404]: expected trait, found type alias `Strings`
+ --> $DIR/suggest-trait-alias-instead-of-type.rs:10:18
+ |
+LL | struct Struct<S: Strings>(S);
+ | ^^^^^^^ type aliases cannot be used as traits
+ |
+help: you might have meant to use `#![feature(trait_alias)]` instead of a `type` alias
+ |
+LL | trait Strings = Iterator<Item=String>;
+ |
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0404`.
diff --git a/src/test/ui/union/union-fields-1.stderr b/src/test/ui/union/union-fields-1.stderr
index 87621cc01b1b9..3595bf6dce688 100644
--- a/src/test/ui/union/union-fields-1.stderr
+++ b/src/test/ui/union/union-fields-1.stderr
@@ -2,8 +2,11 @@ error: field is never read: `c`
--> $DIR/union-fields-1.rs:6:5
|
LL | c: u8,
- | ^^^^^
+ | -^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_c`
|
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
note: the lint level is defined here
--> $DIR/union-fields-1.rs:1:9
|
@@ -14,19 +17,31 @@ error: field is never read: `a`
--> $DIR/union-fields-1.rs:9:5
|
LL | a: u8,
- | ^^^^^
+ | -^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_a`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: field is never read: `a`
--> $DIR/union-fields-1.rs:13:20
|
LL | union NoDropLike { a: u8 }
- | ^^^^^
+ | -^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_a`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: field is never read: `c`
--> $DIR/union-fields-1.rs:18:5
|
LL | c: u8,
- | ^^^^^
+ | -^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_c`
+ |
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
error: aborting due to 4 previous errors
diff --git a/src/test/ui/union/union-lint-dead-code.stderr b/src/test/ui/union/union-lint-dead-code.stderr
index 7de70ec33801f..8ead9cde9b333 100644
--- a/src/test/ui/union/union-lint-dead-code.stderr
+++ b/src/test/ui/union/union-lint-dead-code.stderr
@@ -2,8 +2,11 @@ error: field is never read: `b`
--> $DIR/union-lint-dead-code.rs:5:5
|
LL | b: bool,
- | ^^^^^^^
+ | -^^^^^^
+ | |
+ | help: if this is intentional, prefix it with an underscore: `_b`
|
+ = note: the leading underscore signals that this field serves some other purpose even if it isn't used in a way that we can detect. (e.g. for its effect when dropped or in foreign code)
note: the lint level is defined here
--> $DIR/union-lint-dead-code.rs:1:9
|
diff --git a/src/tools/rust-analyzer b/src/tools/rust-analyzer
index 7be06139b632e..7570212a544b8 160000
--- a/src/tools/rust-analyzer
+++ b/src/tools/rust-analyzer
@@ -1 +1 @@
-Subproject commit 7be06139b632ee615fc18af04dd67947e2c794b2
+Subproject commit 7570212a544b8e973a7d57be3657aae6465028a7