Auto merge of #149729 - matthiaskrgr:rollup-25plwn0, r=matthiaskrgr

Rollup of 4 pull requests

Successful merges:

 - #147136 (Add warn-by-default lint for visibility on `const _` declarations)
 - #149498 (Tidying up `tests/ui/issues` tests [1/N])
 - #149721 (rustc book: fix `*-pc-windows-msvc` link label in sidebar)
 - #149724 (Fix off-by-one staging output when testing the library)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

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};
@@ -1339,14 +1339,26 @@ 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 {
                         span: item.span,
                         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, .. }) => {

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

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),
     }
 }

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,

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,
+}

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.
     ///

compiler/rustc_lint_defs/src/lib.rs

@@ -696,6 +696,7 @@ pub enum BuiltinLintDiag {
         extern_crate: Symbol,
         local_crate: Symbol,
     },
+    UnusedVisibility(Span),
     AttributeLint(AttributeLintKind),
 }
 

src/bootstrap/src/core/build_steps/test.rs

@@ -2818,10 +2818,15 @@ fn run_cargo_test<'a>(
     builder: &Builder<'_>,
 ) -> bool {
     let compiler = cargo.compiler();
+    let stage = match cargo.mode() {
+        Mode::Std => compiler.stage,
+        _ => compiler.stage + 1,
+    };
+
     let mut cargo = prepare_cargo_test(cargo, libtest_args, crates, target, builder);
     let _time = helpers::timeit(builder);
-    let _group =
-        description.into().and_then(|what| builder.msg_test(what, target, compiler.stage + 1));
+
+    let _group = description.into().and_then(|what| builder.msg_test(what, target, stage));
 
     #[cfg(feature = "build-metrics")]
     builder.metrics.begin_test_suite(

src/bootstrap/src/core/builder/cargo.rs

@@ -98,6 +98,7 @@ pub struct Cargo {
     command: BootstrapCommand,
     args: Vec<OsString>,
     compiler: Compiler,
+    mode: Mode,
     target: TargetSelection,
     rustflags: Rustflags,
     rustdocflags: Rustflags,
@@ -141,6 +142,10 @@ impl Cargo {
         self.compiler
     }
 
+    pub fn mode(&self) -> Mode {
+        self.mode
+    }
+
     pub fn into_cmd(self) -> BootstrapCommand {
         self.into()
     }
@@ -1404,6 +1409,7 @@ impl Builder<'_> {
             command: cargo,
             args: vec![],
             compiler,
+            mode,
             target,
             rustflags,
             rustdocflags,

src/doc/rustc/src/SUMMARY.md

@@ -130,7 +130,7 @@
     - [\*-unknown-openbsd](platform-support/openbsd.md)
     - [\*-unknown-redox](platform-support/redox.md)
     - [\*-unknown-uefi](platform-support/unknown-uefi.md)
-    - [\*-unknown-windows-msvc](platform-support/windows-msvc.md)
+    - [\*-pc-windows-msvc](platform-support/windows-msvc.md)
     - [\*-uwp-windows-msvc](platform-support/uwp-windows-msvc.md)
     - [\*-wrs-vxworks](platform-support/vxworks.md)
     - [wasm32-wasip1](platform-support/wasm32-wasip1.md)