Auto merge of #126891 - matthiaskrgr:rollup-p6dl1gk, r=matthiaskrgr

Rollup of 9 pull requests
Successful merges:
- #126177 (Add hard error and migration lint for unsafe attrs)
- #126298 (Promote loongarch64-unknown-linux-musl to Tier 2 with host tools)
- #126455 (For [E0308]: mismatched types, when expr is in an arm's body, not add semicolon ';' at the end of it.)
- #126754 (Implement `use<>` formatting in rustfmt)
- #126807 (std::unix::fs: copy simplification for apple.)
- #126845 (Weekly `cargo update`)
- #126849 (Fix 32-bit Arm reg classes by hierarchically sorting them)
- #126854 (std::unix::os::home_dir: fallback's optimisation.)
- #126888 (Remove stray println from rustfmt's `rewrite_static`)
r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Cargo.lock

@@ -899,7 +899,7 @@ fn validate_generic_param_order(dcx: DiagCtxtHandle<'_>, generics: &[GenericPara
 
 impl<'a>Visitor<'a>forAstValidator<'a>{
 fnvisit_attribute(&mutself,attr:&Attribute){
- validate_attr::check_attr(&self.session.psess, attr);
+ validate_attr::check_attr(&self.features,&self.session.psess, attr);
 }
 
 fnvisit_ty(&mutself,ty:&'aTy){

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -1883,7 +1883,7 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
 letmut span:Option<Span> = None;
 whileletSome(attr) = attrs.next(){
  rustc_ast_passes::feature_gate::check_attribute(attr,self.cx.sess, features);
- validate_attr::check_attr(&self.cx.sess.psess, attr);
+ validate_attr::check_attr(features,&self.cx.sess.psess, attr);
 
 let current_span = ifletSome(sp) = span { sp.to(attr.span)}else{ attr.span};
  span = Some(current_span);

compiler/rustc_expand/src/expand.rs

@@ -1145,10 +1145,6 @@ pub fn is_valid_for_get_attr(name: Symbol) -> bool {
 })
 }
 
-pubfnis_unsafe_attr(name:Symbol) -> bool{
-BUILTIN_ATTRIBUTE_MAP.get(&name).is_some_and(|attr| attr.safety == AttributeSafety::Unsafe)
-}
-
 pubstaticBUILTIN_ATTRIBUTE_MAP:LazyLock<FxHashMap<Symbol,&BuiltinAttribute>> =
 LazyLock::new(|| {
 letmut map = FxHashMap::default();

compiler/rustc_feature/src/builtin_attrs.rs

@@ -125,7 +125,7 @@ pub use accepted::ACCEPTED_FEATURES;
 pubuse builtin_attrs::AttributeDuplicates;
 pubuse builtin_attrs::{
  deprecated_attributes, encode_cross_crate, find_gated_cfg, is_builtin_attr_name,
-is_unsafe_attr,is_valid_for_get_attr,AttributeGate,AttributeTemplate,AttributeType,
+ is_valid_for_get_attr,AttributeGate,AttributeSafety,AttributeTemplate,AttributeType,
 BuiltinAttribute,GatedCfg,BUILTIN_ATTRIBUTES,BUILTIN_ATTRIBUTE_MAP,
 };
 pubuse removed::REMOVED_FEATURES;

compiler/rustc_feature/src/lib.rs

@@ -26,10 +26,8 @@ use rustc_middle::lint::in_external_macro;
 use rustc_middle::middle::stability::EvalResult;
 use rustc_middle::span_bug;
 use rustc_middle::ty::print::with_no_trimmed_paths;
-use rustc_middle::ty::{
-self, suggest_constraining_type_params,Article,Binder,IsSuggestable,Ty,TypeVisitableExt,
-Upcast,
-};
+use rustc_middle::ty::{self, suggest_constraining_type_params,Article,Binder};
+use rustc_middle::ty::{IsSuggestable,Ty,TyCtxt,TypeVisitableExt,Upcast};
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{sym,Ident};
@@ -1111,12 +1109,56 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 self.tcx.hir().span_with_body(self.tcx.local_def_id_to_hir_id(fn_id)),
 )
 {
- err.multipart_suggestion(
+// When the expr is in a match arm's body, we shouldn't add semicolon ';' at the end.
+// For example:
+// fn mismatch_types() -> i32 {
+// match 1 {
+// x => dbg!(x),
+// }
+// todo!()
+// }
+// -------------^^^^^^^-
+// Don't add semicolon `;` at the end of `dbg!(x)` expr
+fnis_in_arm<'tcx>(expr:&'tcx hir::Expr<'tcx>,tcx:TyCtxt<'tcx>) -> bool{
+for(_, node)in tcx.hir().parent_iter(expr.hir_id){
+match node {
+ hir::Node::Block(block) => {
+ifletSome(ret) = block.expr
+ && ret.hir_id == expr.hir_id
+{
+continue;
+}
+}
+ hir::Node::Arm(arm) => {
+iflet hir::ExprKind::Block(block, _) = arm.body.kind
+ && letSome(ret) = block.expr
+ && ret.hir_id == expr.hir_id
+{
+returntrue;
+}
+}
+ hir::Node::Expr(e)iflet hir::ExprKind::Block(block, _) = e.kind => {
+ifletSome(ret) = block.expr
+ && ret.hir_id == expr.hir_id
+{
+continue;
+}
+}
+ _ => {
+returnfalse;
+}
+}
+}
+
+false
+}
+letmut suggs = vec![(span.shrink_to_lo(),"return ".to_string())];
+if !is_in_arm(expr,self.tcx){
+ suggs.push((span.shrink_to_hi(),";".to_string()));
+}
+ err.multipart_suggestion_verbose(
 "you might have meant to return this value",
-vec![
-(span.shrink_to_lo(),"return ".to_string()),
-(span.shrink_to_hi(),";".to_string()),
-],
+ suggs,
 Applicability::MaybeIncorrect,
 );
 }

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -825,6 +825,10 @@ lint_unnameable_test_items = cannot test inner items
 lint_unnecessary_qualification = unnecessary qualification
 .suggestion = remove the unnecessary path segments
 
+lint_unsafe_attr_outside_unsafe = unsafe attribute used without unsafe
+.label = usage of unsafe attribute
+lint_unsafe_attr_outside_unsafe_suggestion = wrap the attribute in `unsafe(...)`
+
 lint_unsupported_group = `{$lint_group}` lint group is not supported with ´--force-warn´
 
 lint_untranslatable_diag = diagnostics should be created using translatable messages

compiler/rustc_lint/messages.ftl

@@ -319,6 +319,16 @@ pub(super) fn decorate_lint(sess: &Session, diagnostic: BuiltinLintDiag, diag: &
 BuiltinLintDiag::UnusedQualifications{ removal_span } => {
  lints::UnusedQualifications{ removal_span }.decorate_lint(diag);
 }
+BuiltinLintDiag::UnsafeAttrOutsideUnsafe{
+ attribute_name_span,
+sugg_spans:(left, right),
+} => {
+ lints::UnsafeAttrOutsideUnsafe{
+span: attribute_name_span,
+suggestion: lints::UnsafeAttrOutsideUnsafeSuggestion{ left, right },
+}
+.decorate_lint(diag);
+}
 BuiltinLintDiag::AssociatedConstElidedLifetime{
  elided,
 span: lt_span,

compiler/rustc_lint/src/context/diagnostics.rs

@@ -2890,3 +2890,24 @@ pub struct RedundantImportVisibility {
 pubimport_vis:String,
 pubmax_vis:String,
 }
+
+#[derive(LintDiagnostic)]
+#[diag(lint_unsafe_attr_outside_unsafe)]
+pubstructUnsafeAttrOutsideUnsafe{
+#[label]
+pubspan:Span,
+#[subdiagnostic]
+pubsuggestion:UnsafeAttrOutsideUnsafeSuggestion,
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(
+ lint_unsafe_attr_outside_unsafe_suggestion,
+ applicability = "machine-applicable"
+)]
+pubstructUnsafeAttrOutsideUnsafeSuggestion{
+#[suggestion_part(code = "unsafe(")]
+publeft:Span,
+#[suggestion_part(code = ")")]
+pubright:Span,
+}

compiler/rustc_lint/src/lints.rs

@@ -115,6 +115,7 @@ declare_lint_pass! {
 UNNAMEABLE_TYPES,
 UNREACHABLE_CODE,
 UNREACHABLE_PATTERNS,
+UNSAFE_ATTR_OUTSIDE_UNSAFE,
 UNSAFE_OP_IN_UNSAFE_FN,
 UNSTABLE_NAME_COLLISIONS,
 UNSTABLE_SYNTAX_PRE_EXPANSION,
@@ -4902,3 +4903,45 @@ declare_lint! {
  reference:"issue #123743 <https://github.com/rust-lang/rust/issues/123743>",
 };
 }
+
+declare_lint!{
+/// The `unsafe_attr_outside_unsafe` lint detects a missing unsafe keyword
+/// on attributes considered unsafe.
+///
+/// ### Example
+///
+/// ```rust
+/// #![feature(unsafe_attributes)]
+/// #![warn(unsafe_attr_outside_unsafe)]
+///
+/// #[no_mangle]
+/// extern "C" fn foo() {}
+///
+/// fn main() {}
+/// ```
+///
+/// {{produces}}
+///
+/// ### Explanation
+///
+/// Some attributes (e.g. `no_mangle`, `export_name`, `link_section` -- see
+/// [issue #82499] for a more complete list) are considered "unsafe" attributes.
+/// An unsafe attribute must only be used inside unsafe(...).
+///
+/// This lint can automatically wrap the attributes in `unsafe(...)` , but this
+/// obviously cannot verify that the preconditions of the `unsafe`
+/// attributes are fulfilled, so that is still up to the user.
+///
+/// The lint is currently "allow" by default, but that might change in the
+/// future.
+///
+/// [editions]: https://doc.rust-lang.org/edition-guide/
+/// [issue #82499]: https://github.com/rust-lang/rust/issues/82499
+pubUNSAFE_ATTR_OUTSIDE_UNSAFE,
+Allow,
+"detects unsafe attributes outside of unsafe",
+ @future_incompatible = FutureIncompatibleInfo{
+ reason:FutureIncompatibilityReason::EditionError(Edition::Edition2024),
+ reference:"issue #123757 <https://github.com/rust-lang/rust/issues/123757>",
+};
+}