diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs index 2790916891a15..ddb19f5e79158 100644 --- a/compiler/rustc_ast_passes/src/ast_validation.rs +++ b/compiler/rustc_ast_passes/src/ast_validation.rs @@ -33,7 +33,7 @@ use rustc_session::Session; use rustc_session::lint::BuiltinLintDiag; use rustc_session::lint::builtin::{ DEPRECATED_WHERE_CLAUSE_LOCATION, MISSING_ABI, MISSING_UNSAFE_ON_EXTERN, - PATTERNS_IN_FNS_WITHOUT_BODY, + PATTERNS_IN_FNS_WITHOUT_BODY, UNUSED_VISIBILITIES, }; use rustc_session::parse::feature_err; use rustc_span::{Ident, Span, kw, sym}; @@ -1339,7 +1339,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> { } }); } - ItemKind::Const(box ConstItem { defaultness, rhs, .. }) => { + ItemKind::Const(box ConstItem { defaultness, ident, rhs, .. }) => { self.check_defaultness(item.span, *defaultness); if rhs.is_none() { self.dcx().emit_err(errors::ConstWithoutBody { @@ -1347,6 +1347,18 @@ impl<'a> Visitor<'a> for AstValidator<'a> { replace_span: self.ending_semi_or_hi(item.span), }); } + if ident.name == kw::Underscore + && !matches!(item.vis.kind, VisibilityKind::Inherited) + && ident.span.eq_ctxt(item.vis.span) + { + self.lint_buffer.buffer_lint( + UNUSED_VISIBILITIES, + item.id, + item.vis.span, + BuiltinLintDiag::UnusedVisibility(item.vis.span), + ) + } + visit::walk_item(self, item); } ItemKind::Static(box StaticItem { expr, safety, .. }) => { diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl index 1bcdda96e13a2..bc1c246b8f03a 100644 --- a/compiler/rustc_lint/messages.ftl +++ b/compiler/rustc_lint/messages.ftl @@ -978,6 +978,10 @@ lint_unused_op = unused {$op} that must be used lint_unused_result = unused result of type `{$ty}` +lint_unused_visibilities = visibility qualifiers have no effect on `const _` declarations + .note = `const _` does not declare a name, so there is nothing for the qualifier to apply to + .suggestion = remove the qualifier + lint_use_let_underscore_ignore_suggestion = use `let _ = ...` to ignore the expression or result lint_useless_ptr_null_checks_fn_ptr = function pointers are not nullable, so checking them for null will always return false diff --git a/compiler/rustc_lint/src/early/diagnostics.rs b/compiler/rustc_lint/src/early/diagnostics.rs index b654bc848ecfc..ff364e5f814ab 100644 --- a/compiler/rustc_lint/src/early/diagnostics.rs +++ b/compiler/rustc_lint/src/early/diagnostics.rs @@ -302,6 +302,9 @@ pub fn decorate_builtin_lint( BuiltinLintDiag::UnusedCrateDependency { extern_crate, local_crate } => { lints::UnusedCrateDependency { extern_crate, local_crate }.decorate_lint(diag) } + BuiltinLintDiag::UnusedVisibility(span) => { + lints::UnusedVisibility { span }.decorate_lint(diag) + } BuiltinLintDiag::AttributeLint(kind) => decorate_attribute_lint(sess, tcx, &kind, diag), } } diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs index a5f9eabf89c4c..4e7a3e4051767 100644 --- a/compiler/rustc_lint/src/lib.rs +++ b/compiler/rustc_lint/src/lib.rs @@ -291,6 +291,7 @@ fn register_builtins(store: &mut LintStore) { "unused", UNUSED_IMPORTS, UNUSED_VARIABLES, + UNUSED_VISIBILITIES, UNUSED_ASSIGNMENTS, DEAD_CODE, UNUSED_MUT, diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs index 4f28d503af3c3..1bec316ce45a7 100644 --- a/compiler/rustc_lint/src/lints.rs +++ b/compiler/rustc_lint/src/lints.rs @@ -3191,3 +3191,11 @@ pub(crate) struct UnsafeAttrOutsideUnsafeSuggestion { #[suggestion_part(code = ")")] pub right: Span, } + +#[derive(LintDiagnostic)] +#[diag(lint_unused_visibilities)] +#[note] +pub(crate) struct UnusedVisibility { + #[suggestion(style = "short", code = "", applicability = "machine-applicable")] + pub span: Span, +} diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index 2f0333160f52b..740530daf2bdb 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -143,6 +143,7 @@ declare_lint_pass! { UNUSED_QUALIFICATIONS, UNUSED_UNSAFE, UNUSED_VARIABLES, + UNUSED_VISIBILITIES, USELESS_DEPRECATED, VARARGS_WITHOUT_PATTERN, WARNINGS, @@ -693,6 +694,26 @@ declare_lint! { "detect variables which are not used in any way" } +declare_lint! { + /// The `unused_visibilities` lint detects visibility qualifiers (like `pub`) + /// on a `const _` item. + /// + /// ### Example + /// + /// ```rust + /// pub const _: () = {}; + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// These qualifiers have no effect, as `const _` items are unnameable. + pub UNUSED_VISIBILITIES, + Warn, + "detect visibility qualifiers on `const _` items" +} + declare_lint! { /// The `unused_assignments` lint detects assignments that will never be read. /// diff --git a/compiler/rustc_lint_defs/src/lib.rs b/compiler/rustc_lint_defs/src/lib.rs index 3c6e7d04a29dd..19ba27a27eafe 100644 --- a/compiler/rustc_lint_defs/src/lib.rs +++ b/compiler/rustc_lint_defs/src/lib.rs @@ -696,6 +696,7 @@ pub enum BuiltinLintDiag { extern_crate: Symbol, local_crate: Symbol, }, + UnusedVisibility(Span), AttributeLint(AttributeLintKind), } diff --git a/src/tools/clippy/tests/ui-toml/absolute_paths/absolute_paths.no_short.stderr b/src/tools/clippy/tests/ui-toml/absolute_paths/absolute_paths.no_short.stderr index 70d71f6c4ea16..c94b7777f3e9f 100644 --- a/src/tools/clippy/tests/ui-toml/absolute_paths/absolute_paths.no_short.stderr +++ b/src/tools/clippy/tests/ui-toml/absolute_paths/absolute_paths.no_short.stderr @@ -71,10 +71,10 @@ LL | impl core::fmt::Display for X | ^^^^^^^^^^^^^^^^^^ error: consider bringing this path into scope with the `use` keyword - --> tests/ui-toml/absolute_paths/absolute_paths.rs:113:14 + --> tests/ui-toml/absolute_paths/absolute_paths.rs:113:10 | -LL | pub const _: crate::S = { - | ^^^^^^^^ +LL | const _: crate::S = { + | ^^^^^^^^ error: consider bringing this path into scope with the `use` keyword --> tests/ui-toml/absolute_paths/absolute_paths.rs:114:9 diff --git a/src/tools/clippy/tests/ui-toml/absolute_paths/absolute_paths.rs b/src/tools/clippy/tests/ui-toml/absolute_paths/absolute_paths.rs index c024f2f513ced..a3982b8f6540d 100644 --- a/src/tools/clippy/tests/ui-toml/absolute_paths/absolute_paths.rs +++ b/src/tools/clippy/tests/ui-toml/absolute_paths/absolute_paths.rs @@ -110,7 +110,7 @@ mod m1 { } //~[no_short]v absolute_paths -pub const _: crate::S = { +const _: crate::S = { let crate::S = m1::S; //~[no_short] absolute_paths crate::m1::S diff --git a/tests/ui/consts/promoted_const_call3.rs b/tests/ui/consts/promoted_const_call3.rs index dc05a3b584424..82e9eac31d5cc 100644 --- a/tests/ui/consts/promoted_const_call3.rs +++ b/tests/ui/consts/promoted_const_call3.rs @@ -4,12 +4,12 @@ pub const C: () = { //~^ ERROR: destructor of `String` cannot be evaluated at compile-time }; -pub const _: () = { +const _: () = { let _: &'static _ = &id(&String::new()); //~^ ERROR: destructor of `String` cannot be evaluated at compile-time }; -pub const _: () = { +const _: () = { let _: &'static _ = &std::mem::ManuallyDrop::new(String::new()); //~^ ERROR: temporary value dropped while borrowed }; diff --git a/tests/ui/consts/ptr_is_null.rs b/tests/ui/consts/ptr_is_null.rs index 8b41f5718e8db..9f8a1697fd70e 100644 --- a/tests/ui/consts/ptr_is_null.rs +++ b/tests/ui/consts/ptr_is_null.rs @@ -5,12 +5,12 @@ const FOO: &usize = &42; -pub const _: () = assert!(!(FOO as *const usize).is_null()); +const _: () = assert!(!(FOO as *const usize).is_null()); -pub const _: () = assert!(!(42 as *const usize).is_null()); +const _: () = assert!(!(42 as *const usize).is_null()); -pub const _: () = assert!((0 as *const usize).is_null()); +const _: () = assert!((0 as *const usize).is_null()); -pub const _: () = assert!(std::ptr::null::().is_null()); +const _: () = assert!(std::ptr::null::().is_null()); -pub const _: () = assert!(!("foo" as *const str).is_null()); +const _: () = assert!(!("foo" as *const str).is_null()); diff --git a/tests/ui/lint/issue-70819-dont-override-forbid-in-same-scope.stderr b/tests/ui/lint/issue-70819-dont-override-forbid-in-same-scope.stderr index 77c8d1eab5845..506791fd17269 100644 --- a/tests/ui/lint/issue-70819-dont-override-forbid-in-same-scope.stderr +++ b/tests/ui/lint/issue-70819-dont-override-forbid-in-same-scope.stderr @@ -413,3 +413,21 @@ note: the lint level is defined here LL | #![forbid(forbidden_lint_groups)] | ^^^^^^^^^^^^^^^^^^^^^ +Future breakage diagnostic: +error: warn(unused) incompatible with previous forbid + --> $DIR/issue-70819-dont-override-forbid-in-same-scope.rs:22:13 + | +LL | #![forbid(unused)] + | ------ `forbid` level set here +LL | #![deny(unused)] +LL | #![warn(unused)] + | ^^^^^^ overruled by previous forbid + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #81670 +note: the lint level is defined here + --> $DIR/issue-70819-dont-override-forbid-in-same-scope.rs:17:11 + | +LL | #![forbid(forbidden_lint_groups)] + | ^^^^^^^^^^^^^^^^^^^^^ + diff --git a/tests/ui/lint/outer-forbid.stderr b/tests/ui/lint/outer-forbid.stderr index 64a1077462abe..7810ca223f8ad 100644 --- a/tests/ui/lint/outer-forbid.stderr +++ b/tests/ui/lint/outer-forbid.stderr @@ -453,3 +453,21 @@ note: the lint level is defined here LL | #![forbid(forbidden_lint_groups)] | ^^^^^^^^^^^^^^^^^^^^^ +Future breakage diagnostic: +error: allow(unused) incompatible with previous forbid + --> $DIR/outer-forbid.rs:25:9 + | +LL | #![forbid(unused, non_snake_case)] + | ------ `forbid` level set here +... +LL | #[allow(unused)] + | ^^^^^^ overruled by previous forbid + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #81670 +note: the lint level is defined here + --> $DIR/outer-forbid.rs:18:11 + | +LL | #![forbid(forbidden_lint_groups)] + | ^^^^^^^^^^^^^^^^^^^^^ + diff --git a/tests/ui/lint/unused-visibilities.fixed b/tests/ui/lint/unused-visibilities.fixed new file mode 100644 index 0000000000000..97c1a5c732497 --- /dev/null +++ b/tests/ui/lint/unused-visibilities.fixed @@ -0,0 +1,29 @@ +//@ check-pass +//@ run-rustfix + +#![warn(unused_visibilities)] + + const _: () = {}; +//~^WARN visibility qualifiers have no effect on `const _` declarations + + const _: () = {}; +//~^WARN visibility qualifiers have no effect on `const _` declarations + +macro_rules! foo { + () => { + const _: () = {}; + //~^WARN visibility qualifiers have no effect on `const _` declarations + }; +} + +foo!(); + +macro_rules! bar { + ($tt:tt) => { + pub const $tt: () = {}; + }; +} + +bar!(_); + +fn main() {} diff --git a/tests/ui/lint/unused-visibilities.rs b/tests/ui/lint/unused-visibilities.rs new file mode 100644 index 0000000000000..4bcbd1201e4ac --- /dev/null +++ b/tests/ui/lint/unused-visibilities.rs @@ -0,0 +1,29 @@ +//@ check-pass +//@ run-rustfix + +#![warn(unused_visibilities)] + +pub const _: () = {}; +//~^WARN visibility qualifiers have no effect on `const _` declarations + +pub(self) const _: () = {}; +//~^WARN visibility qualifiers have no effect on `const _` declarations + +macro_rules! foo { + () => { + pub const _: () = {}; + //~^WARN visibility qualifiers have no effect on `const _` declarations + }; +} + +foo!(); + +macro_rules! bar { + ($tt:tt) => { + pub const $tt: () = {}; + }; +} + +bar!(_); + +fn main() {} diff --git a/tests/ui/lint/unused-visibilities.stderr b/tests/ui/lint/unused-visibilities.stderr new file mode 100644 index 0000000000000..e5ff2a7fcae8d --- /dev/null +++ b/tests/ui/lint/unused-visibilities.stderr @@ -0,0 +1,35 @@ +warning: visibility qualifiers have no effect on `const _` declarations + --> $DIR/unused-visibilities.rs:6:1 + | +LL | pub const _: () = {}; + | ^^^ help: remove the qualifier + | + = note: `const _` does not declare a name, so there is nothing for the qualifier to apply to +note: the lint level is defined here + --> $DIR/unused-visibilities.rs:4:9 + | +LL | #![warn(unused_visibilities)] + | ^^^^^^^^^^^^^^^^^^^ + +warning: visibility qualifiers have no effect on `const _` declarations + --> $DIR/unused-visibilities.rs:9:1 + | +LL | pub(self) const _: () = {}; + | ^^^^^^^^^ help: remove the qualifier + | + = note: `const _` does not declare a name, so there is nothing for the qualifier to apply to + +warning: visibility qualifiers have no effect on `const _` declarations + --> $DIR/unused-visibilities.rs:14:9 + | +LL | pub const _: () = {}; + | ^^^ help: remove the qualifier +... +LL | foo!(); + | ------ in this macro invocation + | + = note: `const _` does not declare a name, so there is nothing for the qualifier to apply to + = note: this warning originates in the macro `foo` (in Nightly builds, run with -Z macro-backtrace for more info) + +warning: 3 warnings emitted + diff --git a/tests/ui/traits/const-traits/call.rs b/tests/ui/traits/const-traits/call.rs index b1080fe78bb5f..360c08e1b7fe9 100644 --- a/tests/ui/traits/const-traits/call.rs +++ b/tests/ui/traits/const-traits/call.rs @@ -3,7 +3,7 @@ #![feature(const_closures, const_trait_impl)] #![allow(incomplete_features)] -pub const _: () = { +const _: () = { assert!((const || true)()); //~^ ERROR }: [const] Fn()` is not satisfied };