Rollup of 8 pull requests

compiler/rustc_builtin_macros/src/test.rs

@@ -112,7 +112,7 @@ pub fn expand_test_or_bench(
     };
 
     // Note: non-associated fn items are already handled by `expand_test_or_bench`
-    if !matches!(item.kind, ast::ItemKind::Fn(_)) {
+    let ast::ItemKind::Fn(fn_) = &item.kind else {
         let diag = &cx.sess.parse_sess.span_diagnostic;
         let msg = "the `#[test]` attribute may only be used on a non-associated function";
         let mut err = match item.kind {
@@ -130,7 +130,7 @@ pub fn expand_test_or_bench(
             .emit();
 
         return vec![Annotatable::Item(item)];
-    }
+    };
 
     // has_*_signature will report any errors in the type so compilation
     // will fail. We shouldn't try to expand in this case because the errors
@@ -141,12 +141,14 @@ pub fn expand_test_or_bench(
         return vec![Annotatable::Item(item)];
     }
 
-    let (sp, attr_sp) = (cx.with_def_site_ctxt(item.span), cx.with_def_site_ctxt(attr_sp));
+    let sp = cx.with_def_site_ctxt(item.span);
+    let ret_ty_sp = cx.with_def_site_ctxt(fn_.sig.decl.output.span());
+    let attr_sp = cx.with_def_site_ctxt(attr_sp);
 
     let test_id = Ident::new(sym::test, attr_sp);
 
     // creates test::$name
-    let test_path = |name| cx.path(sp, vec![test_id, Ident::from_str_and_span(name, sp)]);
+    let test_path = |name| cx.path(ret_ty_sp, vec![test_id, Ident::from_str_and_span(name, sp)]);
 
     // creates test::ShouldPanic::$name
     let should_panic_path = |name| {
@@ -192,7 +194,7 @@ pub fn expand_test_or_bench(
                         vec![
                             // super::$test_fn(b)
                             cx.expr_call(
-                                sp,
+                                ret_ty_sp,
                                 cx.expr_path(cx.path(sp, vec![item.ident])),
                                 vec![cx.expr_ident(sp, b)],
                             ),
@@ -216,7 +218,11 @@ pub fn expand_test_or_bench(
                         cx.expr_path(test_path("assert_test_result")),
                         vec![
                             // $test_fn()
-                            cx.expr_call(sp, cx.expr_path(cx.path(sp, vec![item.ident])), vec![]), // )
+                            cx.expr_call(
+                                ret_ty_sp,
+                                cx.expr_path(cx.path(sp, vec![item.ident])),
+                                vec![],
+                            ), // )
                         ],
                     ), // }
                 ), // )

compiler/rustc_error_codes/src/error_codes/E0706.md

@@ -56,4 +56,4 @@ You might be interested in visiting the [async book] for further information.
 [`async-trait` crate]: https://crates.io/crates/async-trait
 [async-is-hard]: https://smallcultfollowing.com/babysteps/blog/2019/10/26/async-fn-in-traits-are-hard/
 [Generic Associated Types]: https://github.com/rust-lang/rust/issues/44265
-[async book]: https://rust-lang.github.io/async-book/07_workarounds/06_async_in_traits.html
+[async book]: https://rust-lang.github.io/async-book/07_workarounds/05_async_in_traits.html

compiler/rustc_error_messages/locales/en-US/hir_analysis.ftl

@@ -150,3 +150,6 @@ hir_analysis_const_bound_for_non_const_trait =
 hir_analysis_self_in_impl_self =
     `Self` is not valid in the self type of an impl block
     .note = replace `Self` with a different type
+
+hir_analysis_op_trait_generic_params =
+    `{$method_name}` must not have any generic parameters

compiler/rustc_error_messages/src/lib.rs

@@ -30,7 +30,8 @@ use intl_memoizer::concurrent::IntlLangMemoizer;
 #[cfg(not(parallel_compiler))]
 use intl_memoizer::IntlLangMemoizer;
 
-pub use fluent_bundle::{FluentArgs, FluentError, FluentValue};
+pub use fluent_bundle::{self, FluentArgs, FluentError, FluentValue};
+
 pub use unic_langid::{langid, LanguageIdentifier};
 
 // Generates `DEFAULT_LOCALE_RESOURCES` static and `fluent_generated` module.

compiler/rustc_errors/src/translation.rs

@@ -1,7 +1,10 @@
 use crate::snippet::Style;
 use crate::{DiagnosticArg, DiagnosticMessage, FluentBundle};
 use rustc_data_structures::sync::Lrc;
-use rustc_error_messages::FluentArgs;
+use rustc_error_messages::{
+    fluent_bundle::resolver::errors::{ReferenceKind, ResolverError},
+    FluentArgs, FluentError,
+};
 use std::borrow::Cow;
 
 /// Convert diagnostic arguments (a rustc internal type that exists to implement
@@ -102,14 +105,31 @@ pub trait Translate {
             .or_else(|| translate_with_bundle(self.fallback_fluent_bundle()))
             .map(|(translated, errs)| {
                 // Always bail out for errors with the fallback bundle.
-                assert!(
-                    errs.is_empty(),
-                    "identifier: {:?}, attr: {:?}, args: {:?}, errors: {:?}",
-                    identifier,
-                    attr,
-                    args,
-                    errs
-                );
+
+                let mut help_messages = vec![];
+
+                if !errs.is_empty() {
+                    for error in &errs {
+                        match error {
+                            FluentError::ResolverError(ResolverError::Reference(
+                                ReferenceKind::Message { id, .. },
+                            )) if args.iter().any(|(arg_id, _)| arg_id == id) => {
+                                help_messages.push(format!("Argument `{id}` exists but was not referenced correctly. Try using `{{${id}}}` instead"));
+                            }
+                            _ => {}
+                        }
+                    }
+
+                    panic!(
+                        "Encountered errors while formatting message for `{identifier}`\n\
+                        help: {}\n\
+                        attr: `{attr:?}`\n\
+                        args: `{args:?}`\n\
+                        errors: `{errs:?}`",
+                        help_messages.join("\nhelp: ")
+                    );
+                }
+
                 translated
             })
             .expect("failed to find message in primary or fallback fluent bundles")

compiler/rustc_hir_typeck/src/errors.rs

@@ -125,3 +125,11 @@ pub struct AddMissingParenthesesInRange {
     #[suggestion_part(code = ")")]
     pub right: Span,
 }
+
+#[derive(Diagnostic)]
+#[diag(hir_analysis_op_trait_generic_params)]
+pub struct OpMethodGenericParams {
+    #[primary_span]
+    pub span: Span,
+    pub method_name: String,
+}

compiler/rustc_hir_typeck/src/method/mod.rs

@@ -10,6 +10,7 @@ mod suggest;
 pub use self::suggest::SelfSource;
 pub use self::MethodError::*;
 
+use crate::errors::OpMethodGenericParams;
 use crate::{Expectation, FnCtxt};
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Applicability, Diagnostic};
@@ -443,7 +444,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
         let def_id = method_item.def_id;
         let generics = tcx.generics_of(def_id);
-        assert_eq!(generics.params.len(), 0);
+
+        if generics.params.len() != 0 {
+            tcx.sess.emit_fatal(OpMethodGenericParams {
+                span: tcx.def_span(method_item.def_id),
+                method_name: m_name.to_string(),
+            });
+        }
 
         debug!("lookup_in_trait_adjusted: method_item={:?}", method_item);
         let mut obligations = vec![];

compiler/rustc_lint/src/unused.rs

@@ -9,7 +9,7 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_infer::traits::util::elaborate_predicates_with_span;
 use rustc_middle::ty::adjustment;
-use rustc_middle::ty::{self, Ty};
+use rustc_middle::ty::{self, DefIdTree, Ty};
 use rustc_span::symbol::Symbol;
 use rustc_span::symbol::{kw, sym};
 use rustc_span::{BytePos, Span};
@@ -87,17 +87,33 @@ declare_lint_pass!(UnusedResults => [UNUSED_MUST_USE, UNUSED_RESULTS]);
 
 impl<'tcx> LateLintPass<'tcx> for UnusedResults {
     fn check_stmt(&mut self, cx: &LateContext<'_>, s: &hir::Stmt<'_>) {
-        let expr = match s.kind {
-            hir::StmtKind::Semi(ref expr) => &**expr,
-            _ => return,
-        };
+        let hir::StmtKind::Semi(expr) = s.kind else { return; };
 
         if let hir::ExprKind::Ret(..) = expr.kind {
             return;
         }
 
+        if let hir::ExprKind::Match(await_expr, _arms, hir::MatchSource::AwaitDesugar) = expr.kind
+            && let ty = cx.typeck_results().expr_ty(&await_expr)
+            && let ty::Opaque(future_def_id, _) = ty.kind()
+            && cx.tcx.ty_is_opaque_future(ty)
+            // FIXME: This also includes non-async fns that return `impl Future`.
+            && let async_fn_def_id = cx.tcx.parent(*future_def_id)
+            && check_must_use_def(
+                cx,
+                async_fn_def_id,
+                expr.span,
+                "output of future returned by ",
+                "",
+            )
+        {
+            // We have a bare `foo().await;` on an opaque type from an async function that was
+            // annotated with `#[must_use]`.
+            return;
+        }
+
         let ty = cx.typeck_results().expr_ty(&expr);
-        let type_permits_lack_of_use = check_must_use_ty(cx, ty, &expr, s.span, "", "", 1);
+        let type_permits_lack_of_use = check_must_use_ty(cx, ty, &expr, expr.span, "", "", 1);
 
         let mut fn_warned = false;
         let mut op_warned = false;
@@ -119,7 +135,7 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults {
             _ => None,
         };
         if let Some(def_id) = maybe_def_id {
-            fn_warned = check_must_use_def(cx, def_id, s.span, "return value of ", "");
+            fn_warned = check_must_use_def(cx, def_id, expr.span, "return value of ", "");
         } else if type_permits_lack_of_use {
             // We don't warn about unused unit or uninhabited types.
             // (See https://github.com/rust-lang/rust/issues/43806 for details.)

compiler/rustc_middle/src/values.rs

@@ -185,7 +185,8 @@ fn find_item_ty_spans(
                 });
                 if check_params && let Some(args) = path.segments.last().unwrap().args {
                     let params_in_repr = tcx.params_in_repr(def_id);
-                    for (i, arg) in args.args.iter().enumerate() {
+                    // the domain size check is needed because the HIR may not be well-formed at this point
+                    for (i, arg) in args.args.iter().enumerate().take(params_in_repr.domain_size()) {
                         if let hir::GenericArg::Type(ty) = arg && params_in_repr.contains(i as u32) {
                             find_item_ty_spans(tcx, ty, needle, spans, seen_representable);
                         }

compiler/rustc_passes/src/check_attr.rs

@@ -139,7 +139,7 @@ impl CheckAttrVisitor<'_> {
                 sym::collapse_debuginfo => self.check_collapse_debuginfo(attr, span, target),
                 sym::const_trait => self.check_const_trait(attr, span, target),
                 sym::must_not_suspend => self.check_must_not_suspend(&attr, span, target),
-                sym::must_use => self.check_must_use(hir_id, &attr, span, target),
+                sym::must_use => self.check_must_use(hir_id, &attr, target),
                 sym::rustc_pass_by_value => self.check_pass_by_value(&attr, span, target),
                 sym::rustc_allow_incoherent_impl => {
                     self.check_allow_incoherent_impl(&attr, span, target)
@@ -1163,17 +1163,7 @@ impl CheckAttrVisitor<'_> {
     }
 
     /// Warns against some misuses of `#[must_use]`
-    fn check_must_use(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) -> bool {
-        let node = self.tcx.hir().get(hir_id);
-        if let Some(kind) = node.fn_kind() && let rustc_hir::IsAsync::Async = kind.asyncness() {
-            self.tcx.emit_spanned_lint(
-                UNUSED_ATTRIBUTES,
-                hir_id,
-                attr.span,
-                errors::MustUseAsync { span }
-            );
-        }
-
+    fn check_must_use(&self, hir_id: HirId, attr: &Attribute, target: Target) -> bool {
         if !matches!(
             target,
             Target::Fn

src/librustdoc/html/format.rs

@@ -107,10 +107,6 @@ impl Buffer {
         self.buffer
     }
 
-    pub(crate) fn insert_str(&mut self, idx: usize, s: &str) {
-        self.buffer.insert_str(idx, s);
-    }
-
     pub(crate) fn push_str(&mut self, s: &str) {
         self.buffer.push_str(s);
     }

src/librustdoc/html/render/context.rs

@@ -69,11 +69,13 @@ pub(crate) struct Context<'tcx> {
     /// the source files are present in the html rendering, then this will be
     /// `true`.
     pub(crate) include_sources: bool,
+    /// Collection of all types with notable traits referenced in the current module.
+    pub(crate) types_with_notable_traits: FxHashSet<clean::Type>,
 }
 
 // `Context` is cloned a lot, so we don't want the size to grow unexpectedly.
 #[cfg(all(not(windows), target_arch = "x86_64", target_pointer_width = "64"))]
-rustc_data_structures::static_assert_size!(Context<'_>, 128);
+rustc_data_structures::static_assert_size!(Context<'_>, 160);
 
 /// Shared mutable state used in [`Context`] and elsewhere.
 pub(crate) struct SharedContext<'tcx> {
@@ -532,6 +534,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             deref_id_map: FxHashMap::default(),
             shared: Rc::new(scx),
             include_sources,
+            types_with_notable_traits: FxHashSet::default(),
         };
 
         if emit_crate {
@@ -560,6 +563,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
             id_map: IdMap::new(),
             shared: Rc::clone(&self.shared),
             include_sources: self.include_sources,
+            types_with_notable_traits: FxHashSet::default(),
         }
     }
 
@@ -803,6 +807,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
                 }
             }
         }
+
         Ok(())
     }