Auto merge of #102875 - Dylan-DPC:rollup-zwcq8h9, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #99696 (Uplift `clippy::for_loops_over_fallibles` lint into rustc)
 - #102055 (Move some tests to more reasonable directories)
 - #102786 (Remove tuple candidate, nothing special about it)
 - #102794 (Make tests capture the error printed by a Result return)
 - #102853 (Skip chained OpaqueCast when building captures.)
 - #102868 (Rename `AssocItemKind::TyAlias` to `AssocItemKind::Type`)

Failed merges:

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

compiler/rustc_ast/src/ast.rs

@@ -2953,7 +2953,7 @@ pub enum AssocItemKind {
     /// An associated function.
     Fn(Box<Fn>),
     /// An associated type.
-    TyAlias(Box<TyAlias>),
+    Type(Box<TyAlias>),
     /// A macro expanding to associated items.
     MacCall(P<MacCall>),
 }
@@ -2963,7 +2963,7 @@ impl AssocItemKind {
         match *self {
             Self::Const(defaultness, ..)
             | Self::Fn(box Fn { defaultness, .. })
-            | Self::TyAlias(box TyAlias { defaultness, .. }) => defaultness,
+            | Self::Type(box TyAlias { defaultness, .. }) => defaultness,
             Self::MacCall(..) => Defaultness::Final,
         }
     }
@@ -2974,7 +2974,7 @@ impl From<AssocItemKind> for ItemKind {
         match assoc_item_kind {
             AssocItemKind::Const(a, b, c) => ItemKind::Const(a, b, c),
             AssocItemKind::Fn(fn_kind) => ItemKind::Fn(fn_kind),
-            AssocItemKind::TyAlias(ty_alias_kind) => ItemKind::TyAlias(ty_alias_kind),
+            AssocItemKind::Type(ty_alias_kind) => ItemKind::TyAlias(ty_alias_kind),
             AssocItemKind::MacCall(a) => ItemKind::MacCall(a),
         }
     }
@@ -2987,7 +2987,7 @@ impl TryFrom<ItemKind> for AssocItemKind {
         Ok(match item_kind {
             ItemKind::Const(a, b, c) => AssocItemKind::Const(a, b, c),
             ItemKind::Fn(fn_kind) => AssocItemKind::Fn(fn_kind),
-            ItemKind::TyAlias(ty_alias_kind) => AssocItemKind::TyAlias(ty_alias_kind),
+            ItemKind::TyAlias(ty_kind) => AssocItemKind::Type(ty_kind),
             ItemKind::MacCall(a) => AssocItemKind::MacCall(a),
             _ => return Err(item_kind),
         })

compiler/rustc_ast/src/mut_visit.rs

@@ -1106,7 +1106,7 @@ pub fn noop_flat_map_assoc_item<T: MutVisitor>(
             visit_fn_sig(sig, visitor);
             visit_opt(body, |body| visitor.visit_block(body));
         }
-        AssocItemKind::TyAlias(box TyAlias {
+        AssocItemKind::Type(box TyAlias {
             defaultness,
             generics,
             where_clauses,

compiler/rustc_ast/src/visit.rs

@@ -244,14 +244,12 @@ pub trait Visitor<'ast>: Sized {
 
 #[macro_export]
 macro_rules! walk_list {
-    ($visitor: expr, $method: ident, $list: expr) => {
+    ($visitor: expr, $method: ident, $list: expr $(, $($extra_args: expr),* )?) => {
+        {
+            #[cfg_attr(not(bootstrap), allow(for_loops_over_fallibles))]
             for elem in $list {
-            $visitor.$method(elem)
+                $visitor.$method(elem $(, $($extra_args,)* )?)
             }
-    };
-    ($visitor: expr, $method: ident, $list: expr, $($extra_args: expr),*) => {
-        for elem in $list {
-            $visitor.$method(elem, $($extra_args,)*)
         }
     }
 }
@@ -685,7 +683,7 @@ pub fn walk_assoc_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a AssocItem,
             let kind = FnKind::Fn(FnCtxt::Assoc(ctxt), ident, sig, vis, generics, body.as_deref());
             visitor.visit_fn(kind, span, id);
         }
-        AssocItemKind::TyAlias(box TyAlias { generics, bounds, ty, .. }) => {
+        AssocItemKind::Type(box TyAlias { generics, bounds, ty, .. }) => {
             visitor.visit_generics(generics);
             walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
             walk_list!(visitor, visit_ty, ty);

compiler/rustc_ast_lowering/src/item.rs

@@ -804,7 +804,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 );
                 (generics, hir::TraitItemKind::Fn(sig, hir::TraitFn::Provided(body_id)), true)
             }
-            AssocItemKind::TyAlias(box TyAlias {
+            AssocItemKind::Type(box TyAlias {
                 ref generics,
                 where_clauses,
                 ref bounds,
@@ -850,7 +850,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     fn lower_trait_item_ref(&mut self, i: &AssocItem) -> hir::TraitItemRef {
         let kind = match &i.kind {
             AssocItemKind::Const(..) => hir::AssocItemKind::Const,
-            AssocItemKind::TyAlias(..) => hir::AssocItemKind::Type,
+            AssocItemKind::Type(..) => hir::AssocItemKind::Type,
             AssocItemKind::Fn(box Fn { sig, .. }) => {
                 hir::AssocItemKind::Fn { has_self: sig.decl.has_self() }
             }
@@ -898,7 +898,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
                 (generics, hir::ImplItemKind::Fn(sig, body_id))
             }
-            AssocItemKind::TyAlias(box TyAlias { generics, where_clauses, ty, .. }) => {
+            AssocItemKind::Type(box TyAlias { generics, where_clauses, ty, .. }) => {
                 let mut generics = generics.clone();
                 add_ty_alias_where_clause(&mut generics, *where_clauses, false);
                 self.lower_generics(
@@ -941,7 +941,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             span: self.lower_span(i.span),
             kind: match &i.kind {
                 AssocItemKind::Const(..) => hir::AssocItemKind::Const,
-                AssocItemKind::TyAlias(..) => hir::AssocItemKind::Type,
+                AssocItemKind::Type(..) => hir::AssocItemKind::Type,
                 AssocItemKind::Fn(box Fn { sig, .. }) => {
                     hir::AssocItemKind::Fn { has_self: sig.decl.has_self() }
                 }

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -1556,7 +1556,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                         });
                     }
                 }
-                AssocItemKind::TyAlias(box TyAlias {
+                AssocItemKind::Type(box TyAlias {
                     generics,
                     where_clauses,
                     where_predicates_split,
@@ -1595,7 +1595,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
         }
 
         match item.kind {
-            AssocItemKind::TyAlias(box TyAlias { ref generics, ref bounds, ref ty, .. })
+            AssocItemKind::Type(box TyAlias { ref generics, ref bounds, ref ty, .. })
                 if ctxt == AssocCtxt::Trait =>
             {
                 self.visit_vis(&item.vis);

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -517,7 +517,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
     fn visit_assoc_item(&mut self, i: &'a ast::AssocItem, ctxt: AssocCtxt) {
         let is_fn = match i.kind {
             ast::AssocItemKind::Fn(_) => true,
-            ast::AssocItemKind::TyAlias(box ast::TyAlias { ref ty, .. }) => {
+            ast::AssocItemKind::Type(box ast::TyAlias { ref ty, .. }) => {
                 if let (Some(_), AssocCtxt::Trait) = (ty, ctxt) {
                     gate_feature_post!(
                         &self,

compiler/rustc_ast_pretty/src/pprust/state/item.rs

@@ -516,7 +516,7 @@ impl<'a> State<'a> {
             ast::AssocItemKind::Const(def, ty, body) => {
                 self.print_item_const(ident, None, ty, body.as_deref(), vis, *def);
             }
-            ast::AssocItemKind::TyAlias(box ast::TyAlias {
+            ast::AssocItemKind::Type(box ast::TyAlias {
                 defaultness,
                 generics,
                 where_clauses,

compiler/rustc_builtin_macros/src/deriving/generic/mod.rs

@@ -566,7 +566,7 @@ impl<'a> TraitDef<'a> {
                     tokens: None,
                 },
                 attrs: ast::AttrVec::new(),
-                kind: ast::AssocItemKind::TyAlias(Box::new(ast::TyAlias {
+                kind: ast::AssocItemKind::Type(Box::new(ast::TyAlias {
                     defaultness: ast::Defaultness::Final,
                     generics: Generics::default(),
                     where_clauses: (

compiler/rustc_lint/src/for_loops_over_fallibles.rs

@@ -0,0 +1,183 @@
+use crate::{LateContext, LateLintPass, LintContext};
+
+use hir::{Expr, Pat};
+use rustc_errors::{Applicability, DelayDm};
+use rustc_hir as hir;
+use rustc_infer::traits::TraitEngine;
+use rustc_infer::{infer::TyCtxtInferExt, traits::ObligationCause};
+use rustc_middle::ty::{self, List};
+use rustc_span::{sym, Span};
+use rustc_trait_selection::traits::TraitEngineExt;
+
+declare_lint! {
+    /// The `for_loops_over_fallibles` lint checks for `for` loops over `Option` or `Result` values.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// let opt = Some(1);
+    /// for x in opt { /* ... */}
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Both `Option` and `Result` implement `IntoIterator` trait, which allows using them in a `for` loop.
+    /// `for` loop over `Option` or `Result` will iterate either 0 (if the value is `None`/`Err(_)`)
+    /// or 1 time (if the value is `Some(_)`/`Ok(_)`). This is not very useful and is more clearly expressed
+    /// via `if let`.
+    ///
+    /// `for` loop can also be accidentally written with the intention to call a function multiple times,
+    /// while the function returns `Some(_)`, in these cases `while let` loop should be used instead.
+    ///
+    /// The "intended" use of `IntoIterator` implementations for `Option` and `Result` is passing them to
+    /// generic code that expects something implementing `IntoIterator`. For example using `.chain(option)`
+    /// to optionally add a value to an iterator.
+    pub FOR_LOOPS_OVER_FALLIBLES,
+    Warn,
+    "for-looping over an `Option` or a `Result`, which is more clearly expressed as an `if let`"
+}
+
+declare_lint_pass!(ForLoopsOverFallibles => [FOR_LOOPS_OVER_FALLIBLES]);
+
+impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+        let Some((pat, arg)) = extract_for_loop(expr) else { return };
+
+        let ty = cx.typeck_results().expr_ty(arg);
+
+        let &ty::Adt(adt, substs) = ty.kind() else { return };
+
+        let (article, ty, var) = match adt.did() {
+            did if cx.tcx.is_diagnostic_item(sym::Option, did) => ("an", "Option", "Some"),
+            did if cx.tcx.is_diagnostic_item(sym::Result, did) => ("a", "Result", "Ok"),
+            _ => return,
+        };
+
+        let msg = DelayDm(|| {
+            format!(
+                "for loop over {article} `{ty}`. This is more readably written as an `if let` statement",
+            )
+        });
+
+        cx.struct_span_lint(FOR_LOOPS_OVER_FALLIBLES, arg.span, msg, |lint| {
+            if let Some(recv) = extract_iterator_next_call(cx, arg)
+            && let Ok(recv_snip) = cx.sess().source_map().span_to_snippet(recv.span)
+            {
+                lint.span_suggestion(
+                    recv.span.between(arg.span.shrink_to_hi()),
+                    format!("to iterate over `{recv_snip}` remove the call to `next`"),
+                    ".by_ref()",
+                    Applicability::MaybeIncorrect
+                );
+            } else {
+                lint.multipart_suggestion_verbose(
+                    format!("to check pattern in a loop use `while let`"),
+                    vec![
+                        // NB can't use `until` here because `expr.span` and `pat.span` have different syntax contexts
+                        (expr.span.with_hi(pat.span.lo()), format!("while let {var}(")),
+                        (pat.span.between(arg.span), format!(") = ")),
+                    ],
+                    Applicability::MaybeIncorrect
+                );
+            }
+
+            if suggest_question_mark(cx, adt, substs, expr.span) {
+                lint.span_suggestion(
+                    arg.span.shrink_to_hi(),
+                    "consider unwrapping the `Result` with `?` to iterate over its contents",
+                    "?",
+                    Applicability::MaybeIncorrect,
+                );
+            }
+
+            lint.multipart_suggestion_verbose(
+                "consider using `if let` to clear intent",
+                vec![
+                    // NB can't use `until` here because `expr.span` and `pat.span` have different syntax contexts
+                    (expr.span.with_hi(pat.span.lo()), format!("if let {var}(")),
+                    (pat.span.between(arg.span), format!(") = ")),
+                ],
+                Applicability::MaybeIncorrect,
+            )
+        })
+    }
+}
+
+fn extract_for_loop<'tcx>(expr: &Expr<'tcx>) -> Option<(&'tcx Pat<'tcx>, &'tcx Expr<'tcx>)> {
+    if let hir::ExprKind::DropTemps(e) = expr.kind
+    && let hir::ExprKind::Match(iterexpr, [arm], hir::MatchSource::ForLoopDesugar) = e.kind
+    && let hir::ExprKind::Call(_, [arg]) = iterexpr.kind
+    && let hir::ExprKind::Loop(block, ..) = arm.body.kind
+    && let [stmt] = block.stmts
+    && let hir::StmtKind::Expr(e) = stmt.kind
+    && let hir::ExprKind::Match(_, [_, some_arm], _) = e.kind
+    && let hir::PatKind::Struct(_, [field], _) = some_arm.pat.kind
+    {
+        Some((field.pat, arg))
+    } else {
+        None
+    }
+}
+
+fn extract_iterator_next_call<'tcx>(
+    cx: &LateContext<'_>,
+    expr: &Expr<'tcx>,
+) -> Option<&'tcx Expr<'tcx>> {
+    // This won't work for `Iterator::next(iter)`, is this an issue?
+    if let hir::ExprKind::MethodCall(_, recv, _, _) = expr.kind
+    && cx.typeck_results().type_dependent_def_id(expr.hir_id) == cx.tcx.lang_items().next_fn()
+    {
+        Some(recv)
+    } else {
+        return None
+    }
+}
+
+fn suggest_question_mark<'tcx>(
+    cx: &LateContext<'tcx>,
+    adt: ty::AdtDef<'tcx>,
+    substs: &List<ty::GenericArg<'tcx>>,
+    span: Span,
+) -> bool {
+    let Some(body_id) = cx.enclosing_body else { return false };
+    let Some(into_iterator_did) = cx.tcx.get_diagnostic_item(sym::IntoIterator) else { return false };
+
+    if !cx.tcx.is_diagnostic_item(sym::Result, adt.did()) {
+        return false;
+    }
+
+    // Check that the function/closure/constant we are in has a `Result` type.
+    // Otherwise suggesting using `?` may not be a good idea.
+    {
+        let ty = cx.typeck_results().expr_ty(&cx.tcx.hir().body(body_id).value);
+        let ty::Adt(ret_adt, ..) = ty.kind() else { return false };
+        if !cx.tcx.is_diagnostic_item(sym::Result, ret_adt.did()) {
+            return false;
+        }
+    }
+
+    let ty = substs.type_at(0);
+    let infcx = cx.tcx.infer_ctxt().build();
+    let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
+
+    let cause = ObligationCause::new(
+        span,
+        body_id.hir_id,
+        rustc_infer::traits::ObligationCauseCode::MiscObligation,
+    );
+    fulfill_cx.register_bound(
+        &infcx,
+        ty::ParamEnv::empty(),
+        // Erase any region vids from the type, which may not be resolved
+        infcx.tcx.erase_regions(ty),
+        into_iterator_did,
+        cause,
+    );
+
+    // Select all, including ambiguous predicates
+    let errors = fulfill_cx.select_all_or_error(&infcx);
+
+    errors.is_empty()
+}

compiler/rustc_lint/src/lib.rs

@@ -52,6 +52,7 @@ mod early;
 mod enum_intrinsics_non_enums;
 mod errors;
 mod expect;
+mod for_loops_over_fallibles;
 pub mod hidden_unicode_codepoints;
 mod internal;
 mod late;
@@ -86,6 +87,7 @@ use rustc_span::Span;
 use array_into_iter::ArrayIntoIter;
 use builtin::*;
 use enum_intrinsics_non_enums::EnumIntrinsicsNonEnums;
+use for_loops_over_fallibles::*;
 use hidden_unicode_codepoints::*;
 use internal::*;
 use let_underscore::*;
@@ -188,6 +190,7 @@ macro_rules! late_lint_mod_passes {
         $macro!(
             $args,
             [
+                ForLoopsOverFallibles: ForLoopsOverFallibles,
                 HardwiredLints: HardwiredLints,
                 ImproperCTypesDeclarations: ImproperCTypesDeclarations,
                 ImproperCTypesDefinitions: ImproperCTypesDefinitions,

compiler/rustc_lint/src/nonstandard_style.rs

@@ -187,7 +187,7 @@ impl EarlyLintPass for NonCamelCaseTypes {
     }
 
     fn check_trait_item(&mut self, cx: &EarlyContext<'_>, it: &ast::AssocItem) {
-        if let ast::AssocItemKind::TyAlias(..) = it.kind {
+        if let ast::AssocItemKind::Type(..) = it.kind {
             self.check_case(cx, "associated type", &it.ident);
         }
     }

compiler/rustc_middle/src/traits/mod.rs

@@ -664,10 +664,6 @@ pub enum ImplSource<'tcx, N> {
 
     /// ImplSource for a `const Drop` implementation.
     ConstDestruct(ImplSourceConstDestructData<N>),
-
-    /// ImplSource for a `std::marker::Tuple` implementation.
-    /// This has no nested predicates ever, so no data.
-    Tuple,
 }
 
 impl<'tcx, N> ImplSource<'tcx, N> {
@@ -682,8 +678,7 @@ impl<'tcx, N> ImplSource<'tcx, N> {
             ImplSource::Object(d) => d.nested,
             ImplSource::FnPointer(d) => d.nested,
             ImplSource::DiscriminantKind(ImplSourceDiscriminantKindData)
-            | ImplSource::Pointee(ImplSourcePointeeData)
+            | ImplSource::Pointee(ImplSourcePointeeData) => vec![],
-            | ImplSource::Tuple => Vec::new(),
             ImplSource::TraitAlias(d) => d.nested,
             ImplSource::TraitUpcasting(d) => d.nested,
             ImplSource::ConstDestruct(i) => i.nested,
@@ -701,8 +696,7 @@ impl<'tcx, N> ImplSource<'tcx, N> {
             ImplSource::Object(d) => &d.nested,
             ImplSource::FnPointer(d) => &d.nested,
             ImplSource::DiscriminantKind(ImplSourceDiscriminantKindData)
-            | ImplSource::Pointee(ImplSourcePointeeData)
+            | ImplSource::Pointee(ImplSourcePointeeData) => &[],
-            | ImplSource::Tuple => &[],
             ImplSource::TraitAlias(d) => &d.nested,
             ImplSource::TraitUpcasting(d) => &d.nested,
             ImplSource::ConstDestruct(i) => &i.nested,
@@ -769,7 +763,6 @@ impl<'tcx, N> ImplSource<'tcx, N> {
                     nested: i.nested.into_iter().map(f).collect(),
                 })
             }
-            ImplSource::Tuple => ImplSource::Tuple,
         }
     }
 }

compiler/rustc_middle/src/traits/select.rs

@@ -161,9 +161,6 @@ pub enum SelectionCandidate<'tcx> {
 
     /// Implementation of `const Destruct`, optionally from a custom `impl const Drop`.
     ConstDestructCandidate(Option<DefId>),
-
-    /// Witnesses the fact that a type is a tuple.
-    TupleCandidate,
 }
 
 /// The result of trait evaluation. The order is important

compiler/rustc_middle/src/traits/structural_impls.rs

@@ -34,8 +34,6 @@ impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSource<'tcx, N> {
             super::ImplSource::TraitUpcasting(ref d) => write!(f, "{:?}", d),
 
             super::ImplSource::ConstDestruct(ref d) => write!(f, "{:?}", d),
-
-            super::ImplSource::Tuple => write!(f, "ImplSource::Tuple"),
         }
     }
 }

compiler/rustc_mir_build/src/build/expr/as_place.rs

@@ -17,6 +17,7 @@ use rustc_target::abi::VariantIdx;
 
 use rustc_index::vec::Idx;
 
+use std::assert_matches::assert_matches;
 use std::iter;
 
 /// The "outermost" place that holds this value.
@@ -232,22 +233,20 @@ fn strip_prefix<'tcx>(
     projections: Vec<PlaceElem<'tcx>>,
     prefix_projections: &[HirProjection<'tcx>],
 ) -> impl Iterator<Item = PlaceElem<'tcx>> {
-    let mut iter = projections.into_iter();
+    let mut iter = projections
-    let mut next = || match iter.next()? {
+        .into_iter()
         // Filter out opaque casts, they are unnecessary in the prefix.
-        ProjectionElem::OpaqueCast(..) => iter.next(),
+        .filter(|elem| !matches!(elem, ProjectionElem::OpaqueCast(..)));
-        other => Some(other),
-    };
     for projection in prefix_projections {
         match projection.kind {
             HirProjectionKind::Deref => {
-                assert!(matches!(next(), Some(ProjectionElem::Deref)));
+                assert_matches!(iter.next(), Some(ProjectionElem::Deref));
             }
             HirProjectionKind::Field(..) => {
                 if base_ty.is_enum() {
-                    assert!(matches!(next(), Some(ProjectionElem::Downcast(..))));
+                    assert_matches!(iter.next(), Some(ProjectionElem::Downcast(..)));
                 }
-                assert!(matches!(next(), Some(ProjectionElem::Field(..))));
+                assert_matches!(iter.next(), Some(ProjectionElem::Field(..)));
             }
             HirProjectionKind::Index | HirProjectionKind::Subslice => {
                 bug!("unexpected projection kind: {:?}", projection);

compiler/rustc_mir_build/src/lib.rs

@@ -2,6 +2,7 @@
 //!
 //! This crate also contains the match exhaustiveness and usefulness checking.
 #![allow(rustc::potential_query_instability)]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
 #![feature(if_let_guard)]

compiler/rustc_passes/src/hir_stats.rs

@@ -620,7 +620,7 @@ impl<'v> ast_visit::Visitor<'v> for StatCollector<'v> {
     fn visit_assoc_item(&mut self, i: &'v ast::AssocItem, ctxt: ast_visit::AssocCtxt) {
         record_variants!(
             (self, i, i.kind, Id::None, ast, AssocItem, AssocItemKind),
-            [Const, Fn, TyAlias, MacCall]
+            [Const, Fn, Type, MacCall]
         );
         ast_visit::walk_assoc_item(self, i, ctxt);
     }

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -1425,7 +1425,7 @@ impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
                     }
                     (DefKind::AssocFn, ValueNS)
                 }
-                AssocItemKind::TyAlias(..) => (DefKind::AssocTy, TypeNS),
+                AssocItemKind::Type(..) => (DefKind::AssocTy, TypeNS),
                 AssocItemKind::MacCall(_) => bug!(), // handled above
             };
 

compiler/rustc_resolve/src/def_collector.rs

@@ -239,7 +239,7 @@ impl<'a, 'b> visit::Visitor<'a> for DefCollector<'a, 'b> {
     fn visit_assoc_item(&mut self, i: &'a AssocItem, ctxt: visit::AssocCtxt) {
         let def_data = match &i.kind {
             AssocItemKind::Fn(..) | AssocItemKind::Const(..) => DefPathData::ValueNs(i.ident.name),
-            AssocItemKind::TyAlias(..) => DefPathData::TypeNs(i.ident.name),
+            AssocItemKind::Type(..) => DefPathData::TypeNs(i.ident.name),
             AssocItemKind::MacCall(..) => return self.visit_macro_invoc(i.id),
         };
 

compiler/rustc_resolve/src/late.rs

@@ -2498,7 +2498,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                 AssocItemKind::Fn(box Fn { generics, .. }) => {
                     walk_assoc_item(self, generics, LifetimeBinderKind::Function, item);
                 }
-                AssocItemKind::TyAlias(box TyAlias { generics, .. }) => self
+                AssocItemKind::Type(box TyAlias { generics, .. }) => self
                     .with_lifetime_rib(LifetimeRibKind::AnonymousReportError, |this| {
                         walk_assoc_item(this, generics, LifetimeBinderKind::Item, item)
                     }),
@@ -2694,8 +2694,8 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                     },
                 );
             }
-            AssocItemKind::TyAlias(box TyAlias { generics, .. }) => {
+            AssocItemKind::Type(box TyAlias { generics, .. }) => {
-                debug!("resolve_implementation AssocItemKind::TyAlias");
+                debug!("resolve_implementation AssocItemKind::Type");
                 // We also need a new scope for the impl item type parameters.
                 self.with_generic_param_rib(
                     &generics.params,
@@ -2770,7 +2770,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         let res = binding.res();
         let Res::Def(def_kind, _) = res else { bug!() };
         match (def_kind, kind) {
-            (DefKind::AssocTy, AssocItemKind::TyAlias(..))
+            (DefKind::AssocTy, AssocItemKind::Type(..))
             | (DefKind::AssocFn, AssocItemKind::Fn(..))
             | (DefKind::AssocConst, AssocItemKind::Const(..)) => {
                 self.r.record_partial_res(id, PartialRes::new(res));
@@ -2784,7 +2784,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         let (code, kind) = match kind {
             AssocItemKind::Const(..) => (rustc_errors::error_code!(E0323), "const"),
             AssocItemKind::Fn(..) => (rustc_errors::error_code!(E0324), "method"),
-            AssocItemKind::TyAlias(..) => (rustc_errors::error_code!(E0325), "type"),
+            AssocItemKind::Type(..) => (rustc_errors::error_code!(E0325), "type"),
             AssocItemKind::MacCall(..) => span_bug!(span, "unexpanded macro"),
         };
         let trait_path = path_names_to_string(path);

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -1482,7 +1482,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
             .filter(|(_, res)| match (kind, res) {
                 (AssocItemKind::Const(..), Res::Def(DefKind::AssocConst, _)) => true,
                 (AssocItemKind::Fn(_), Res::Def(DefKind::AssocFn, _)) => true,
-                (AssocItemKind::TyAlias(..), Res::Def(DefKind::AssocTy, _)) => true,
+                (AssocItemKind::Type(..), Res::Def(DefKind::AssocTy, _)) => true,
                 _ => false,
             })
             .map(|(key, _)| key.ident.name)
@@ -1546,7 +1546,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                             AssocSuggestion::MethodWithSelf
                         }
                         ast::AssocItemKind::Fn(..) => AssocSuggestion::AssocFn,
-                        ast::AssocItemKind::TyAlias(..) => AssocSuggestion::AssocType,
+                        ast::AssocItemKind::Type(..) => AssocSuggestion::AssocType,
                         ast::AssocItemKind::MacCall(_) => continue,
                     });
                 }

compiler/rustc_trait_selection/src/traits/project.rs

@@ -1750,8 +1750,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
             super::ImplSource::AutoImpl(..)
             | super::ImplSource::Builtin(..)
             | super::ImplSource::TraitUpcasting(_)
-            | super::ImplSource::ConstDestruct(_)
+            | super::ImplSource::ConstDestruct(_) => {
-            | super::ImplSource::Tuple => {
                 // These traits have no associated types.
                 selcx.tcx().sess.delay_span_bug(
                     obligation.cause.span,
@@ -1829,8 +1828,7 @@ fn confirm_select_candidate<'cx, 'tcx>(
         | super::ImplSource::Builtin(..)
         | super::ImplSource::TraitUpcasting(_)
         | super::ImplSource::TraitAlias(..)
-        | super::ImplSource::ConstDestruct(_)
+        | super::ImplSource::ConstDestruct(_) => {
-        | super::ImplSource::Tuple => {
             // we don't create Select candidates with this kind of resolution
             span_bug!(
                 obligation.cause.span,

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -1021,7 +1021,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         let self_ty = self.infcx().shallow_resolve(obligation.self_ty().skip_binder());
         match self_ty.kind() {
             ty::Tuple(_) => {
-                candidates.vec.push(TupleCandidate);
+                candidates.vec.push(BuiltinCandidate { has_nested: false });
             }
             ty::Infer(ty::TyVar(_)) => {
                 candidates.ambiguous = true;

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -126,8 +126,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 let data = self.confirm_const_destruct_candidate(obligation, def_id)?;
                 ImplSource::ConstDestruct(data)
             }
-
-            TupleCandidate => ImplSource::Tuple,
         };
 
         if !obligation.predicate.is_const_if_const() {

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -1562,7 +1562,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         };
 
         // (*) Prefer `BuiltinCandidate { has_nested: false }`, `PointeeCandidate`,
-        // `DiscriminantKindCandidate`, `ConstDestructCandidate`, and `TupleCandidate`
+        // `DiscriminantKindCandidate`, `ConstDestructCandidate`
         // to anything else.
         //
         // This is a fix for #53123 and prevents winnowing from accidentally extending the
@@ -1583,8 +1583,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 BuiltinCandidate { has_nested: false }
                 | DiscriminantKindCandidate
                 | PointeeCandidate
-                | ConstDestructCandidate(_)
+                | ConstDestructCandidate(_),
-                | TupleCandidate,
                 _,
             ) => true,
             (
@@ -1592,8 +1591,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 BuiltinCandidate { has_nested: false }
                 | DiscriminantKindCandidate
                 | PointeeCandidate
-                | ConstDestructCandidate(_)
+                | ConstDestructCandidate(_),
-                | TupleCandidate,
             ) => false,
 
             (ParamCandidate(other), ParamCandidate(victim)) => {

compiler/rustc_ty_utils/src/instance.rs

@@ -267,8 +267,7 @@ fn resolve_associated_item<'tcx>(
         | traits::ImplSource::DiscriminantKind(..)
         | traits::ImplSource::Pointee(..)
         | traits::ImplSource::TraitUpcasting(_)
-        | traits::ImplSource::ConstDestruct(_)
+        | traits::ImplSource::ConstDestruct(_) => None,
-        | traits::ImplSource::Tuple => None,
     })
 }
 

library/core/tests/option.rs

@@ -57,6 +57,7 @@ fn test_get_resource() {
 }
 
 #[test]
+#[cfg_attr(not(bootstrap), allow(for_loops_over_fallibles))]
 fn test_option_dance() {
     let x = Some(());
     let mut y = Some(5);

library/std/src/io/mod.rs

@@ -262,6 +262,7 @@ use crate::sys_common::memchr;
 
 #[stable(feature = "bufwriter_into_parts", since = "1.56.0")]
 pub use self::buffered::WriterPanicked;
+pub(crate) use self::stdio::attempt_print_to_stderr;
 #[unstable(feature = "internal_output_capture", issue = "none")]
 #[doc(no_inline, hidden)]
 pub use self::stdio::set_output_capture;

library/std/src/io/stdio.rs

@@ -999,7 +999,18 @@ fn print_to<T>(args: fmt::Arguments<'_>, global_s: fn() -> T, label: &str)
 where
     T: Write,
 {
-    if OUTPUT_CAPTURE_USED.load(Ordering::Relaxed)
+    if print_to_buffer_if_capture_used(args) {
+        // Successfully wrote to capture buffer.
+        return;
+    }
+
+    if let Err(e) = global_s().write_fmt(args) {
+        panic!("failed printing to {label}: {e}");
+    }
+}
+
+fn print_to_buffer_if_capture_used(args: fmt::Arguments<'_>) -> bool {
+    OUTPUT_CAPTURE_USED.load(Ordering::Relaxed)
         && OUTPUT_CAPTURE.try_with(|s| {
             // Note that we completely remove a local sink to write to in case
             // our printing recursively panics/prints, so the recursive
@@ -1009,14 +1020,19 @@ where
                 s.set(Some(w));
             })
         }) == Ok(Some(()))
-    {
+}
-        // Successfully wrote to capture buffer.
+
+/// Used by impl Termination for Result to print error after `main` or a test
+/// has returned. Should avoid panicking, although we can't help it if one of
+/// the Display impls inside args decides to.
+pub(crate) fn attempt_print_to_stderr(args: fmt::Arguments<'_>) {
+    if print_to_buffer_if_capture_used(args) {
         return;
     }
 
-    if let Err(e) = global_s().write_fmt(args) {
+    // Ignore error if the write fails, for example because stderr is already
-        panic!("failed printing to {label}: {e}");
+    // closed. There is not much point panicking at this point.
-    }
+    let _ = stderr().write_fmt(args);
 }
 
 #[unstable(

library/std/src/process.rs

@@ -2200,9 +2200,7 @@ impl<T: Termination, E: fmt::Debug> Termination for Result<T, E> {
         match self {
             Ok(val) => val.report(),
             Err(err) => {
-                // Ignore error if the write fails, for example because stderr is
+                io::attempt_print_to_stderr(format_args_nl!("Error: {err:?}"));
-                // already closed. There is not much point panicking at this point.
-                let _ = writeln!(io::stderr(), "Error: {err:?}");
                 ExitCode::FAILURE
             }
         }

src/test/ui/closures/issue-102089-multiple-opaque-cast.rs

@@ -0,0 +1,17 @@
+// edition:2021
+// check-pass
+
+pub struct Example<'a, T> {
+  a: T,
+  b: &'a T,
+}
+
+impl<'a, T> Example<'a, T> {
+  pub fn error_trying_to_destructure_self_in_closure(self) {
+    let closure = || {
+      let Self { a, b } = self;
+    };
+  }
+}
+
+fn main() {}

src/test/ui/drop/dropck_legal_cycles.rs

@@ -1017,7 +1017,7 @@ impl<'a> Children<'a> for HM<'a> {
         where C: Context + PrePost<Self>, Self: Sized
     {
         if let Some(ref hm) = self.contents.get() {
-            for (k, v) in hm.iter().nth(index / 2) {
+            if let Some((k, v)) = hm.iter().nth(index / 2) {
                 [k, v][index % 2].descend_into_self(context);
             }
         }
@@ -1032,7 +1032,7 @@ impl<'a> Children<'a> for VD<'a> {
         where C: Context + PrePost<Self>, Self: Sized
     {
         if let Some(ref vd) = self.contents.get() {
-            for r in vd.iter().nth(index) {
+            if let Some(r) = vd.iter().nth(index) {
                 r.descend_into_self(context);
             }
         }
@@ -1047,7 +1047,7 @@ impl<'a> Children<'a> for VM<'a> {
         where C: Context + PrePost<VM<'a>>
     {
         if let Some(ref vd) = self.contents.get() {
-            for (_idx, r) in vd.iter().nth(index) {
+            if let Some((_idx, r)) = vd.iter().nth(index) {
                 r.descend_into_self(context);
             }
         }
@@ -1062,7 +1062,7 @@ impl<'a> Children<'a> for LL<'a> {
         where C: Context + PrePost<LL<'a>>
     {
         if let Some(ref ll) = self.contents.get() {
-            for r in ll.iter().nth(index) {
+            if let Some(r) = ll.iter().nth(index) {
                 r.descend_into_self(context);
             }
         }
@@ -1077,7 +1077,7 @@ impl<'a> Children<'a> for BH<'a> {
         where C: Context + PrePost<BH<'a>>
     {
         if let Some(ref bh) = self.contents.get() {
-            for r in bh.iter().nth(index) {
+            if let Some(r) = bh.iter().nth(index) {
                 r.descend_into_self(context);
             }
         }
@@ -1092,7 +1092,7 @@ impl<'a> Children<'a> for BTM<'a> {
         where C: Context + PrePost<BTM<'a>>
     {
         if let Some(ref bh) = self.contents.get() {
-            for (k, v) in bh.iter().nth(index / 2) {
+            if let Some((k, v)) = bh.iter().nth(index / 2) {
                 [k, v][index % 2].descend_into_self(context);
             }
         }
@@ -1107,7 +1107,7 @@ impl<'a> Children<'a> for BTS<'a> {
         where C: Context + PrePost<BTS<'a>>
     {
         if let Some(ref bh) = self.contents.get() {
-            for r in bh.iter().nth(index) {
+            if let Some(r) = bh.iter().nth(index) {
                 r.descend_into_self(context);
             }
         }

src/test/ui/issues/issue-30371.rs

@@ -1,5 +1,6 @@
 // run-pass
 #![allow(unreachable_code)]
+#![allow(for_loops_over_fallibles)]
 #![deny(unused_variables)]
 
 fn main() {

src/test/ui/issues/issue-3563-2.rs

@@ -1,14 +0,0 @@
-// check-pass
-// pretty-expanded FIXME #23616
-
-trait Canvas {
-    fn add_point(&self, point: &isize);
-    fn add_points(&self, shapes: &[isize]) {
-        for pt in shapes {
-            self.add_point(pt)
-        }
-    }
-
-}
-
-pub fn main() {}

src/test/ui/lint/for_loop_over_fallibles.rs

@@ -0,0 +1,43 @@
+// check-pass
+
+fn main() {
+    // Common
+    for _ in Some(1) {}
+    //~^ WARN for loop over an `Option`. This is more readably written as an `if let` statement
+    //~| HELP to check pattern in a loop use `while let`
+    //~| HELP consider using `if let` to clear intent
+    for _ in Ok::<_, ()>(1) {}
+    //~^ WARN for loop over a `Result`. This is more readably written as an `if let` statement
+    //~| HELP to check pattern in a loop use `while let`
+    //~| HELP consider using `if let` to clear intent
+
+    // `Iterator::next` specific
+    for _ in [0; 0].iter().next() {}
+    //~^ WARN for loop over an `Option`. This is more readably written as an `if let` statement
+    //~| HELP to iterate over `[0; 0].iter()` remove the call to `next`
+    //~| HELP consider using `if let` to clear intent
+
+    // `Result<impl Iterator, _>`, but function doesn't return `Result`
+    for _ in Ok::<_, ()>([0; 0].iter()) {}
+    //~^ WARN for loop over a `Result`. This is more readably written as an `if let` statement
+    //~| HELP to check pattern in a loop use `while let`
+    //~| HELP consider using `if let` to clear intent
+}
+
+fn _returns_result() -> Result<(), ()> {
+    // `Result<impl Iterator, _>`
+    for _ in Ok::<_, ()>([0; 0].iter()) {}
+    //~^ WARN for loop over a `Result`. This is more readably written as an `if let` statement
+    //~| HELP to check pattern in a loop use `while let`
+    //~| HELP consider unwrapping the `Result` with `?` to iterate over its contents
+    //~| HELP consider using `if let` to clear intent
+
+    // `Result<impl IntoIterator>`
+    for _ in Ok::<_, ()>([0; 0]) {}
+    //~^ WARN for loop over a `Result`. This is more readably written as an `if let` statement
+    //~| HELP to check pattern in a loop use `while let`
+    //~| HELP consider unwrapping the `Result` with `?` to iterate over its contents
+    //~| HELP consider using `if let` to clear intent
+
+    Ok(())
+}

src/test/ui/lint/for_loop_over_fallibles.stderr

@@ -0,0 +1,101 @@
+warning: for loop over an `Option`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:5:14
+   |
+LL |     for _ in Some(1) {}
+   |              ^^^^^^^
+   |
+   = note: `#[warn(for_loops_over_fallibles)]` on by default
+help: to check pattern in a loop use `while let`
+   |
+LL |     while let Some(_) = Some(1) {}
+   |     ~~~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+   |
+LL |     if let Some(_) = Some(1) {}
+   |     ~~~~~~~~~~~~ ~~~
+
+warning: for loop over a `Result`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:9:14
+   |
+LL |     for _ in Ok::<_, ()>(1) {}
+   |              ^^^^^^^^^^^^^^
+   |
+help: to check pattern in a loop use `while let`
+   |
+LL |     while let Ok(_) = Ok::<_, ()>(1) {}
+   |     ~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+   |
+LL |     if let Ok(_) = Ok::<_, ()>(1) {}
+   |     ~~~~~~~~~~ ~~~
+
+warning: for loop over an `Option`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:15:14
+   |
+LL |     for _ in [0; 0].iter().next() {}
+   |              ^^^^^^^^^^^^^^^^^^^^
+   |
+help: to iterate over `[0; 0].iter()` remove the call to `next`
+   |
+LL |     for _ in [0; 0].iter().by_ref() {}
+   |                           ~~~~~~~~~
+help: consider using `if let` to clear intent
+   |
+LL |     if let Some(_) = [0; 0].iter().next() {}
+   |     ~~~~~~~~~~~~ ~~~
+
+warning: for loop over a `Result`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:21:14
+   |
+LL |     for _ in Ok::<_, ()>([0; 0].iter()) {}
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: to check pattern in a loop use `while let`
+   |
+LL |     while let Ok(_) = Ok::<_, ()>([0; 0].iter()) {}
+   |     ~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+   |
+LL |     if let Ok(_) = Ok::<_, ()>([0; 0].iter()) {}
+   |     ~~~~~~~~~~ ~~~
+
+warning: for loop over a `Result`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:29:14
+   |
+LL |     for _ in Ok::<_, ()>([0; 0].iter()) {}
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: to check pattern in a loop use `while let`
+   |
+LL |     while let Ok(_) = Ok::<_, ()>([0; 0].iter()) {}
+   |     ~~~~~~~~~~~~~ ~~~
+help: consider unwrapping the `Result` with `?` to iterate over its contents
+   |
+LL |     for _ in Ok::<_, ()>([0; 0].iter())? {}
+   |                                        +
+help: consider using `if let` to clear intent
+   |
+LL |     if let Ok(_) = Ok::<_, ()>([0; 0].iter()) {}
+   |     ~~~~~~~~~~ ~~~
+
+warning: for loop over a `Result`. This is more readably written as an `if let` statement
+  --> $DIR/for_loop_over_fallibles.rs:36:14
+   |
+LL |     for _ in Ok::<_, ()>([0; 0]) {}
+   |              ^^^^^^^^^^^^^^^^^^^
+   |
+help: to check pattern in a loop use `while let`
+   |
+LL |     while let Ok(_) = Ok::<_, ()>([0; 0]) {}
+   |     ~~~~~~~~~~~~~ ~~~
+help: consider unwrapping the `Result` with `?` to iterate over its contents
+   |
+LL |     for _ in Ok::<_, ()>([0; 0])? {}
+   |                                 +
+help: consider using `if let` to clear intent
+   |
+LL |     if let Ok(_) = Ok::<_, ()>([0; 0]) {}
+   |     ~~~~~~~~~~ ~~~
+
+warning: 6 warnings emitted
+

src/test/ui/span/issue-7575.rs

@@ -1,75 +0,0 @@
-// Test the mechanism for warning about possible missing `self` declarations.
-trait CtxtFn {
-    fn f8(self, _: usize) -> usize;
-    fn f9(_: usize) -> usize;
-}
-
-trait OtherTrait {
-    fn f9(_: usize) -> usize;
-}
-
-// Note: this trait is not implemented, but we can't really tell
-// whether or not an impl would match anyhow without a self
-// declaration to match against, so we wind up prisizeing it as a
-// candidate. This seems not unreasonable -- perhaps the user meant to
-// implement it, after all.
-trait UnusedTrait {
-    fn f9(_: usize) -> usize;
-}
-
-impl CtxtFn for usize {
-    fn f8(self, i: usize) -> usize {
-        i * 4
-    }
-
-    fn f9(i: usize) -> usize {
-        i * 4
-    }
-}
-
-impl OtherTrait for usize {
-    fn f9(i: usize) -> usize {
-        i * 8
-    }
-}
-
-struct Myisize(isize);
-
-impl Myisize {
-    fn fff(i: isize) -> isize {
-        i
-    }
-}
-
-trait ManyImplTrait {
-    fn is_str() -> bool {
-        false
-    }
-}
-
-impl ManyImplTrait for String {
-    fn is_str() -> bool {
-        true
-    }
-}
-
-impl ManyImplTrait for usize {}
-impl ManyImplTrait for isize {}
-impl ManyImplTrait for char {}
-impl ManyImplTrait for Myisize {}
-
-fn no_param_bound(u: usize, m: Myisize) -> usize {
-    u.f8(42) + u.f9(342) + m.fff(42)
-            //~^ ERROR no method named `f9` found
-            //~| ERROR no method named `fff` found
-
-
-}
-
-fn param_bound<T: ManyImplTrait>(t: T) -> bool {
-    t.is_str()
-    //~^ ERROR no method named `is_str` found
-}
-
-fn main() {
-}

src/test/ui/span/issue-7575.stderr

@@ -1,82 +0,0 @@
-error[E0599]: no method named `f9` found for type `usize` in the current scope
-  --> $DIR/issue-7575.rs:62:18
-   |
-LL |     u.f8(42) + u.f9(342) + m.fff(42)
-   |                  ^^ this is an associated function, not a method
-   |
-   = note: found the following associated functions; to be used as methods, functions must have a `self` parameter
-note: candidate #1 is defined in the trait `CtxtFn`
-  --> $DIR/issue-7575.rs:4:5
-   |
-LL |     fn f9(_: usize) -> usize;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: candidate #2 is defined in the trait `OtherTrait`
-  --> $DIR/issue-7575.rs:8:5
-   |
-LL |     fn f9(_: usize) -> usize;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: candidate #3 is defined in the trait `UnusedTrait`
-  --> $DIR/issue-7575.rs:17:5
-   |
-LL |     fn f9(_: usize) -> usize;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
-   = help: items from traits can only be used if the trait is implemented and in scope
-   = note: the following traits define an item `f9`, perhaps you need to implement one of them:
-           candidate #1: `CtxtFn`
-           candidate #2: `OtherTrait`
-           candidate #3: `UnusedTrait`
-help: disambiguate the associated function for candidate #1
-   |
-LL |     u.f8(42) + <usize as CtxtFn>::f9(u, 342) + m.fff(42)
-   |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-help: disambiguate the associated function for candidate #2
-   |
-LL |     u.f8(42) + <usize as OtherTrait>::f9(u, 342) + m.fff(42)
-   |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-help: disambiguate the associated function for candidate #3
-   |
-LL |     u.f8(42) + <usize as UnusedTrait>::f9(u, 342) + m.fff(42)
-   |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-error[E0599]: no method named `fff` found for struct `Myisize` in the current scope
-  --> $DIR/issue-7575.rs:62:30
-   |
-LL | struct Myisize(isize);
-   | -------------- method `fff` not found for this struct
-...
-LL |     u.f8(42) + u.f9(342) + m.fff(42)
-   |                            --^^^
-   |                            | |
-   |                            | this is an associated function, not a method
-   |                            help: use associated function syntax instead: `Myisize::fff`
-   |
-   = note: found the following associated functions; to be used as methods, functions must have a `self` parameter
-note: the candidate is defined in an impl for the type `Myisize`
-  --> $DIR/issue-7575.rs:39:5
-   |
-LL |     fn fff(i: isize) -> isize {
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0599]: no method named `is_str` found for type parameter `T` in the current scope
-  --> $DIR/issue-7575.rs:70:7
-   |
-LL | fn param_bound<T: ManyImplTrait>(t: T) -> bool {
-   |                - method `is_str` not found for this type parameter
-LL |     t.is_str()
-   |       ^^^^^^ this is an associated function, not a method
-   |
-   = note: found the following associated functions; to be used as methods, functions must have a `self` parameter
-note: the candidate is defined in the trait `ManyImplTrait`
-  --> $DIR/issue-7575.rs:45:5
-   |
-LL |     fn is_str() -> bool {
-   |     ^^^^^^^^^^^^^^^^^^^
-   = help: items from traits can only be used if the type parameter is bounded by the trait
-help: disambiguate the associated function for the candidate
-   |
-LL |     <T as ManyImplTrait>::is_str(t)
-   |
-
-error: aborting due to 3 previous errors
-
-For more information about this error, try `rustc --explain E0599`.

src/test/ui/stats/hir-stats.stderr

@@ -26,7 +26,7 @@ ast-stats-1 Block                    288 ( 3.4%)             6            48
 ast-stats-1 GenericBound             352 ( 4.2%)             4            88
 ast-stats-1 - Trait                    352 ( 4.2%)             4
 ast-stats-1 AssocItem                416 ( 4.9%)             4           104
-ast-stats-1 - TyAlias                  208 ( 2.5%)             2
+ast-stats-1 - Type                     208 ( 2.5%)             2
 ast-stats-1 - Fn                       208 ( 2.5%)             2
 ast-stats-1 GenericParam             480 ( 5.7%)             5            96
 ast-stats-1 PathSegment              720 ( 8.6%)            30            24
@@ -84,7 +84,7 @@ ast-stats-2 Block                    288 ( 3.1%)             6            48
 ast-stats-2 GenericBound             352 ( 3.8%)             4            88
 ast-stats-2 - Trait                    352 ( 3.8%)             4
 ast-stats-2 AssocItem                416 ( 4.5%)             4           104
-ast-stats-2 - TyAlias                  208 ( 2.3%)             2
+ast-stats-2 - Type                     208 ( 2.3%)             2
 ast-stats-2 - Fn                       208 ( 2.3%)             2
 ast-stats-2 GenericParam             480 ( 5.2%)             5            96
 ast-stats-2 PathSegment              792 ( 8.7%)            33            24

src/tools/clippy/clippy_lints/src/lib.register_all.rs

@@ -109,7 +109,6 @@ store.register_group(true, "clippy::all", Some("clippy_all"), vec![
     LintId::of(loops::EMPTY_LOOP),
     LintId::of(loops::EXPLICIT_COUNTER_LOOP),
     LintId::of(loops::FOR_KV_MAP),
-    LintId::of(loops::FOR_LOOPS_OVER_FALLIBLES),
     LintId::of(loops::ITER_NEXT_LOOP),
     LintId::of(loops::MANUAL_FIND),
     LintId::of(loops::MANUAL_FLATTEN),

src/tools/clippy/clippy_lints/src/lib.register_lints.rs

@@ -227,7 +227,6 @@ store.register_lints(&[
     loops::EXPLICIT_INTO_ITER_LOOP,
     loops::EXPLICIT_ITER_LOOP,
     loops::FOR_KV_MAP,
-    loops::FOR_LOOPS_OVER_FALLIBLES,
     loops::ITER_NEXT_LOOP,
     loops::MANUAL_FIND,
     loops::MANUAL_FLATTEN,

src/tools/clippy/clippy_lints/src/lib.register_suspicious.rs

@@ -21,7 +21,6 @@ store.register_group(true, "clippy::suspicious", Some("clippy_suspicious"), vec!
     LintId::of(formatting::SUSPICIOUS_ELSE_FORMATTING),
     LintId::of(formatting::SUSPICIOUS_UNARY_OP_FORMATTING),
     LintId::of(loops::EMPTY_LOOP),
-    LintId::of(loops::FOR_LOOPS_OVER_FALLIBLES),
     LintId::of(loops::MUT_RANGE_BOUND),
     LintId::of(methods::NO_EFFECT_REPLACE),
     LintId::of(methods::SUSPICIOUS_MAP),

src/tools/clippy/clippy_lints/src/loops/for_loops_over_fallibles.rs

@@ -1,65 +0,0 @@
-use super::FOR_LOOPS_OVER_FALLIBLES;
-use clippy_utils::diagnostics::span_lint_and_help;
-use clippy_utils::source::snippet;
-use clippy_utils::ty::is_type_diagnostic_item;
-use rustc_hir::{Expr, Pat};
-use rustc_lint::LateContext;
-use rustc_span::symbol::sym;
-
-/// Checks for `for` loops over `Option`s and `Result`s.
-pub(super) fn check(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>, method_name: Option<&str>) {
-    let ty = cx.typeck_results().expr_ty(arg);
-    if is_type_diagnostic_item(cx, ty, sym::Option) {
-        let help_string = if let Some(method_name) = method_name {
-            format!(
-                "consider replacing `for {0} in {1}.{method_name}()` with `if let Some({0}) = {1}`",
-                snippet(cx, pat.span, "_"),
-                snippet(cx, arg.span, "_")
-            )
-        } else {
-            format!(
-                "consider replacing `for {0} in {1}` with `if let Some({0}) = {1}`",
-                snippet(cx, pat.span, "_"),
-                snippet(cx, arg.span, "_")
-            )
-        };
-        span_lint_and_help(
-            cx,
-            FOR_LOOPS_OVER_FALLIBLES,
-            arg.span,
-            &format!(
-                "for loop over `{0}`, which is an `Option`. This is more readably written as an \
-                `if let` statement",
-                snippet(cx, arg.span, "_")
-            ),
-            None,
-            &help_string,
-        );
-    } else if is_type_diagnostic_item(cx, ty, sym::Result) {
-        let help_string = if let Some(method_name) = method_name {
-            format!(
-                "consider replacing `for {0} in {1}.{method_name}()` with `if let Ok({0}) = {1}`",
-                snippet(cx, pat.span, "_"),
-                snippet(cx, arg.span, "_")
-            )
-        } else {
-            format!(
-                "consider replacing `for {0} in {1}` with `if let Ok({0}) = {1}`",
-                snippet(cx, pat.span, "_"),
-                snippet(cx, arg.span, "_")
-            )
-        };
-        span_lint_and_help(
-            cx,
-            FOR_LOOPS_OVER_FALLIBLES,
-            arg.span,
-            &format!(
-                "for loop over `{0}`, which is a `Result`. This is more readably written as an \
-                `if let` statement",
-                snippet(cx, arg.span, "_")
-            ),
-            None,
-            &help_string,
-        );
-    }
-}

src/tools/clippy/clippy_lints/src/loops/iter_next_loop.rs

@@ -5,7 +5,7 @@ use rustc_hir::Expr;
 use rustc_lint::LateContext;
 use rustc_span::sym;
 
-pub(super) fn check(cx: &LateContext<'_>, arg: &Expr<'_>) -> bool {
+pub(super) fn check(cx: &LateContext<'_>, arg: &Expr<'_>) {
     if is_trait_method(cx, arg, sym::Iterator) {
         span_lint(
             cx,
@@ -14,8 +14,5 @@ pub(super) fn check(cx: &LateContext<'_>, arg: &Expr<'_>) -> bool {
             "you are iterating over `Iterator::next()` which is an Option; this will compile but is \
             probably not what you want",
         );
-        true
-    } else {
-        false
     }
 }

src/tools/clippy/clippy_lints/src/loops/mod.rs

@@ -3,7 +3,6 @@ mod explicit_counter_loop;
 mod explicit_into_iter_loop;
 mod explicit_iter_loop;
 mod for_kv_map;
-mod for_loops_over_fallibles;
 mod iter_next_loop;
 mod manual_find;
 mod manual_flatten;
@@ -173,49 +172,6 @@ declare_clippy_lint! {
     "for-looping over `_.next()` which is probably not intended"
 }
 
-declare_clippy_lint! {
-    /// ### What it does
-    /// Checks for `for` loops over `Option` or `Result` values.
-    ///
-    /// ### Why is this bad?
-    /// Readability. This is more clearly expressed as an `if
-    /// let`.
-    ///
-    /// ### Example
-    /// ```rust
-    /// # let opt = Some(1);
-    /// # let res: Result<i32, std::io::Error> = Ok(1);
-    /// for x in opt {
-    ///     // ..
-    /// }
-    ///
-    /// for x in &res {
-    ///     // ..
-    /// }
-    ///
-    /// for x in res.iter() {
-    ///     // ..
-    /// }
-    /// ```
-    ///
-    /// Use instead:
-    /// ```rust
-    /// # let opt = Some(1);
-    /// # let res: Result<i32, std::io::Error> = Ok(1);
-    /// if let Some(x) = opt {
-    ///     // ..
-    /// }
-    ///
-    /// if let Ok(x) = res {
-    ///     // ..
-    /// }
-    /// ```
-    #[clippy::version = "1.45.0"]
-    pub FOR_LOOPS_OVER_FALLIBLES,
-    suspicious,
-    "for-looping over an `Option` or a `Result`, which is more clearly expressed as an `if let`"
-}
-
 declare_clippy_lint! {
     /// ### What it does
     /// Detects `loop + match` combinations that are easier
@@ -648,7 +604,6 @@ declare_lint_pass!(Loops => [
     EXPLICIT_ITER_LOOP,
     EXPLICIT_INTO_ITER_LOOP,
     ITER_NEXT_LOOP,
-    FOR_LOOPS_OVER_FALLIBLES,
     WHILE_LET_LOOP,
     NEEDLESS_COLLECT,
     EXPLICIT_COUNTER_LOOP,
@@ -739,30 +694,22 @@ fn check_for_loop<'tcx>(
     manual_find::check(cx, pat, arg, body, span, expr);
 }
 
-fn check_for_loop_arg(cx: &LateContext<'_>, pat: &Pat<'_>, arg: &Expr<'_>) {
+fn check_for_loop_arg(cx: &LateContext<'_>, _: &Pat<'_>, arg: &Expr<'_>) {
-    let mut next_loop_linted = false; // whether or not ITER_NEXT_LOOP lint was used
-
     if let ExprKind::MethodCall(method, self_arg, [], _) = arg.kind {
         let method_name = method.ident.as_str();
         // check for looping over x.iter() or x.iter_mut(), could use &x or &mut x
         match method_name {
             "iter" | "iter_mut" => {
                 explicit_iter_loop::check(cx, self_arg, arg, method_name);
-                for_loops_over_fallibles::check(cx, pat, self_arg, Some(method_name));
             },
             "into_iter" => {
                 explicit_iter_loop::check(cx, self_arg, arg, method_name);
                 explicit_into_iter_loop::check(cx, self_arg, arg);
-                for_loops_over_fallibles::check(cx, pat, self_arg, Some(method_name));
             },
             "next" => {
-                next_loop_linted = iter_next_loop::check(cx, arg);
+                iter_next_loop::check(cx, arg);
             },
             _ => {},
         }
     }
-
-    if !next_loop_linted {
-        for_loops_over_fallibles::check(cx, pat, arg, None);
-    }
 }

src/tools/clippy/clippy_lints/src/renamed_lints.rs

@@ -11,8 +11,8 @@ pub static RENAMED_LINTS: &[(&str, &str)] = &[
     ("clippy::disallowed_method", "clippy::disallowed_methods"),
     ("clippy::disallowed_type", "clippy::disallowed_types"),
     ("clippy::eval_order_dependence", "clippy::mixed_read_write_in_expression"),
-    ("clippy::for_loop_over_option", "clippy::for_loops_over_fallibles"),
+    ("clippy::for_loop_over_option", "for_loops_over_fallibles"),
-    ("clippy::for_loop_over_result", "clippy::for_loops_over_fallibles"),
+    ("clippy::for_loop_over_result", "for_loops_over_fallibles"),
     ("clippy::identity_conversion", "clippy::useless_conversion"),
     ("clippy::if_let_some_result", "clippy::match_result_ok"),
     ("clippy::logic_bug", "clippy::overly_complex_bool_expr"),
@@ -31,6 +31,7 @@ pub static RENAMED_LINTS: &[(&str, &str)] = &[
     ("clippy::to_string_in_display", "clippy::recursive_format_impl"),
     ("clippy::zero_width_space", "clippy::invisible_characters"),
     ("clippy::drop_bounds", "drop_bounds"),
+    ("clippy::for_loops_over_fallibles", "for_loops_over_fallibles"),
     ("clippy::into_iter_on_array", "array_into_iter"),
     ("clippy::invalid_atomic_ordering", "invalid_atomic_ordering"),
     ("clippy::invalid_ref", "invalid_value"),

src/tools/clippy/clippy_utils/src/ast_utils.rs

@@ -438,14 +438,14 @@ pub fn eq_assoc_item_kind(l: &AssocItemKind, r: &AssocItemKind) -> bool {
             eq_defaultness(*ld, *rd) && eq_fn_sig(lf, rf) && eq_generics(lg, rg) && both(lb, rb, |l, r| eq_block(l, r))
         },
         (
-            TyAlias(box ast::TyAlias {
+            Type(box ast::TyAlias {
                 defaultness: ld,
                 generics: lg,
                 bounds: lb,
                 ty: lt,
                 ..
             }),
-            TyAlias(box ast::TyAlias {
+            Type(box ast::TyAlias {
                 defaultness: rd,
                 generics: rg,
                 bounds: rb,

src/tools/clippy/src/docs.rs

@@ -170,7 +170,6 @@ docs! {
     "fn_to_numeric_cast_any",
     "fn_to_numeric_cast_with_truncation",
     "for_kv_map",
-    "for_loops_over_fallibles",
     "forget_copy",
     "forget_non_drop",
     "forget_ref",

src/tools/clippy/src/docs/for_loops_over_fallibles.txt

@@ -1,32 +0,0 @@
-### What it does
-Checks for `for` loops over `Option` or `Result` values.
-
-### Why is this bad?
-Readability. This is more clearly expressed as an `if
-let`.
-
-### Example
-```
-for x in opt {
-    // ..
-}
-
-for x in &res {
-    // ..
-}
-
-for x in res.iter() {
-    // ..
-}
-```
-
-Use instead:
-```
-if let Some(x) = opt {
-    // ..
-}
-
-if let Ok(x) = res {
-    // ..
-}
-```

src/tools/clippy/tests/ui/for_loop_unfixable.rs

@@ -8,6 +8,7 @@
     clippy::for_kv_map
 )]
 #[allow(clippy::linkedlist, clippy::unnecessary_mut_passed, clippy::similar_names)]
+#[allow(for_loops_over_fallibles)]
 fn main() {
     let vec = vec![1, 2, 3, 4];
 

src/tools/clippy/tests/ui/for_loop_unfixable.stderr

@@ -1,5 +1,5 @@
 error: you are iterating over `Iterator::next()` which is an Option; this will compile but is probably not what you want
-  --> $DIR/for_loop_unfixable.rs:14:15
+  --> $DIR/for_loop_unfixable.rs:15:15
    |
 LL |     for _v in vec.iter().next() {}
    |               ^^^^^^^^^^^^^^^^^

src/tools/clippy/tests/ui/for_loops_over_fallibles.rs

@@ -1,73 +0,0 @@
-#![warn(clippy::for_loops_over_fallibles)]
-#![allow(clippy::uninlined_format_args)]
-
-fn for_loops_over_fallibles() {
-    let option = Some(1);
-    let mut result = option.ok_or("x not found");
-    let v = vec![0, 1, 2];
-
-    // check over an `Option`
-    for x in option {
-        println!("{}", x);
-    }
-
-    // check over an `Option`
-    for x in option.iter() {
-        println!("{}", x);
-    }
-
-    // check over a `Result`
-    for x in result {
-        println!("{}", x);
-    }
-
-    // check over a `Result`
-    for x in result.iter_mut() {
-        println!("{}", x);
-    }
-
-    // check over a `Result`
-    for x in result.into_iter() {
-        println!("{}", x);
-    }
-
-    for x in option.ok_or("x not found") {
-        println!("{}", x);
-    }
-
-    // make sure LOOP_OVER_NEXT lint takes clippy::precedence when next() is the last call
-    // in the chain
-    for x in v.iter().next() {
-        println!("{}", x);
-    }
-
-    // make sure we lint when next() is not the last call in the chain
-    for x in v.iter().next().and(Some(0)) {
-        println!("{}", x);
-    }
-
-    for x in v.iter().next().ok_or("x not found") {
-        println!("{}", x);
-    }
-
-    // check for false positives
-
-    // for loop false positive
-    for x in v {
-        println!("{}", x);
-    }
-
-    // while let false positive for Option
-    while let Some(x) = option {
-        println!("{}", x);
-        break;
-    }
-
-    // while let false positive for Result
-    while let Ok(x) = result {
-        println!("{}", x);
-        break;
-    }
-}
-
-fn main() {}

src/tools/clippy/tests/ui/for_loops_over_fallibles.stderr

@@ -1,95 +0,0 @@
-error: for loop over `option`, which is an `Option`. This is more readably written as an `if let` statement
-  --> $DIR/for_loops_over_fallibles.rs:10:14
-   |
-LL |     for x in option {
-   |              ^^^^^^
-   |
-   = help: consider replacing `for x in option` with `if let Some(x) = option`
-   = note: `-D clippy::for-loops-over-fallibles` implied by `-D warnings`
-
-error: for loop over `option`, which is an `Option`. This is more readably written as an `if let` statement
-  --> $DIR/for_loops_over_fallibles.rs:15:14
-   |
-LL |     for x in option.iter() {
-   |              ^^^^^^
-   |
-   = help: consider replacing `for x in option.iter()` with `if let Some(x) = option`
-
-error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
-  --> $DIR/for_loops_over_fallibles.rs:20:14
-   |
-LL |     for x in result {
-   |              ^^^^^^
-   |
-   = help: consider replacing `for x in result` with `if let Ok(x) = result`
-
-error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
-  --> $DIR/for_loops_over_fallibles.rs:25:14
-   |
-LL |     for x in result.iter_mut() {
-   |              ^^^^^^
-   |
-   = help: consider replacing `for x in result.iter_mut()` with `if let Ok(x) = result`
-
-error: for loop over `result`, which is a `Result`. This is more readably written as an `if let` statement
-  --> $DIR/for_loops_over_fallibles.rs:30:14
-   |
-LL |     for x in result.into_iter() {
-   |              ^^^^^^
-   |
-   = help: consider replacing `for x in result.into_iter()` with `if let Ok(x) = result`
-
-error: for loop over `option.ok_or("x not found")`, which is a `Result`. This is more readably written as an `if let` statement
-  --> $DIR/for_loops_over_fallibles.rs:34:14
-   |
-LL |     for x in option.ok_or("x not found") {
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider replacing `for x in option.ok_or("x not found")` with `if let Ok(x) = option.ok_or("x not found")`
-
-error: you are iterating over `Iterator::next()` which is an Option; this will compile but is probably not what you want
-  --> $DIR/for_loops_over_fallibles.rs:40:14
-   |
-LL |     for x in v.iter().next() {
-   |              ^^^^^^^^^^^^^^^
-   |
-   = note: `#[deny(clippy::iter_next_loop)]` on by default
-
-error: for loop over `v.iter().next().and(Some(0))`, which is an `Option`. This is more readably written as an `if let` statement
-  --> $DIR/for_loops_over_fallibles.rs:45:14
-   |
-LL |     for x in v.iter().next().and(Some(0)) {
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider replacing `for x in v.iter().next().and(Some(0))` with `if let Some(x) = v.iter().next().and(Some(0))`
-
-error: for loop over `v.iter().next().ok_or("x not found")`, which is a `Result`. This is more readably written as an `if let` statement
-  --> $DIR/for_loops_over_fallibles.rs:49:14
-   |
-LL |     for x in v.iter().next().ok_or("x not found") {
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider replacing `for x in v.iter().next().ok_or("x not found")` with `if let Ok(x) = v.iter().next().ok_or("x not found")`
-
-error: this loop never actually loops
-  --> $DIR/for_loops_over_fallibles.rs:61:5
-   |
-LL | /     while let Some(x) = option {
-LL | |         println!("{}", x);
-LL | |         break;
-LL | |     }
-   | |_____^
-   |
-   = note: `#[deny(clippy::never_loop)]` on by default
-
-error: this loop never actually loops
-  --> $DIR/for_loops_over_fallibles.rs:67:5
-   |
-LL | /     while let Ok(x) = result {
-LL | |         println!("{}", x);
-LL | |         break;
-LL | |     }
-   | |_____^
-
-error: aborting due to 11 previous errors
-

src/tools/clippy/tests/ui/manual_map_option.fixed

@@ -7,7 +7,7 @@
     clippy::unit_arg,
     clippy::match_ref_pats,
     clippy::redundant_pattern_matching,
-    clippy::for_loops_over_fallibles,
+    for_loops_over_fallibles,
     dead_code
 )]
 

src/tools/clippy/tests/ui/manual_map_option.rs

@@ -7,7 +7,7 @@
     clippy::unit_arg,
     clippy::match_ref_pats,
     clippy::redundant_pattern_matching,
-    clippy::for_loops_over_fallibles,
+    for_loops_over_fallibles,
     dead_code
 )]
 

src/tools/clippy/tests/ui/rename.fixed

@@ -12,7 +12,7 @@
 #![allow(clippy::disallowed_methods)]
 #![allow(clippy::disallowed_types)]
 #![allow(clippy::mixed_read_write_in_expression)]
-#![allow(clippy::for_loops_over_fallibles)]
+#![allow(for_loops_over_fallibles)]
 #![allow(clippy::useless_conversion)]
 #![allow(clippy::match_result_ok)]
 #![allow(clippy::overly_complex_bool_expr)]
@@ -45,8 +45,8 @@
 #![warn(clippy::disallowed_methods)]
 #![warn(clippy::disallowed_types)]
 #![warn(clippy::mixed_read_write_in_expression)]
-#![warn(clippy::for_loops_over_fallibles)]
+#![warn(for_loops_over_fallibles)]
-#![warn(clippy::for_loops_over_fallibles)]
+#![warn(for_loops_over_fallibles)]
 #![warn(clippy::useless_conversion)]
 #![warn(clippy::match_result_ok)]
 #![warn(clippy::overly_complex_bool_expr)]
@@ -65,6 +65,7 @@
 #![warn(clippy::recursive_format_impl)]
 #![warn(clippy::invisible_characters)]
 #![warn(drop_bounds)]
+#![warn(for_loops_over_fallibles)]
 #![warn(array_into_iter)]
 #![warn(invalid_atomic_ordering)]
 #![warn(invalid_value)]

src/tools/clippy/tests/ui/rename.rs

@@ -12,7 +12,7 @@
 #![allow(clippy::disallowed_methods)]
 #![allow(clippy::disallowed_types)]
 #![allow(clippy::mixed_read_write_in_expression)]
-#![allow(clippy::for_loops_over_fallibles)]
+#![allow(for_loops_over_fallibles)]
 #![allow(clippy::useless_conversion)]
 #![allow(clippy::match_result_ok)]
 #![allow(clippy::overly_complex_bool_expr)]
@@ -65,6 +65,7 @@
 #![warn(clippy::to_string_in_display)]
 #![warn(clippy::zero_width_space)]
 #![warn(clippy::drop_bounds)]
+#![warn(clippy::for_loops_over_fallibles)]
 #![warn(clippy::into_iter_on_array)]
 #![warn(clippy::invalid_atomic_ordering)]
 #![warn(clippy::invalid_ref)]

src/tools/clippy/tests/ui/rename.stderr

@@ -54,17 +54,17 @@ error: lint `clippy::eval_order_dependence` has been renamed to `clippy::mixed_r
 LL | #![warn(clippy::eval_order_dependence)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::mixed_read_write_in_expression`
 
-error: lint `clippy::for_loop_over_option` has been renamed to `clippy::for_loops_over_fallibles`
+error: lint `clippy::for_loop_over_option` has been renamed to `for_loops_over_fallibles`
   --> $DIR/rename.rs:48:9
    |
 LL | #![warn(clippy::for_loop_over_option)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::for_loops_over_fallibles`
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles`
 
-error: lint `clippy::for_loop_over_result` has been renamed to `clippy::for_loops_over_fallibles`
+error: lint `clippy::for_loop_over_result` has been renamed to `for_loops_over_fallibles`
   --> $DIR/rename.rs:49:9
    |
 LL | #![warn(clippy::for_loop_over_result)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::for_loops_over_fallibles`
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles`
 
 error: lint `clippy::identity_conversion` has been renamed to `clippy::useless_conversion`
   --> $DIR/rename.rs:50:9
@@ -174,59 +174,65 @@ error: lint `clippy::drop_bounds` has been renamed to `drop_bounds`
 LL | #![warn(clippy::drop_bounds)]
    |         ^^^^^^^^^^^^^^^^^^^ help: use the new name: `drop_bounds`
 
-error: lint `clippy::into_iter_on_array` has been renamed to `array_into_iter`
+error: lint `clippy::for_loops_over_fallibles` has been renamed to `for_loops_over_fallibles`
   --> $DIR/rename.rs:68:9
    |
+LL | #![warn(clippy::for_loops_over_fallibles)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles`
+
+error: lint `clippy::into_iter_on_array` has been renamed to `array_into_iter`
+  --> $DIR/rename.rs:69:9
+   |
 LL | #![warn(clippy::into_iter_on_array)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `array_into_iter`
 
 error: lint `clippy::invalid_atomic_ordering` has been renamed to `invalid_atomic_ordering`
-  --> $DIR/rename.rs:69:9
+  --> $DIR/rename.rs:70:9
    |
 LL | #![warn(clippy::invalid_atomic_ordering)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_atomic_ordering`
 
 error: lint `clippy::invalid_ref` has been renamed to `invalid_value`
-  --> $DIR/rename.rs:70:9
+  --> $DIR/rename.rs:71:9
    |
 LL | #![warn(clippy::invalid_ref)]
    |         ^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_value`
 
 error: lint `clippy::mem_discriminant_non_enum` has been renamed to `enum_intrinsics_non_enums`
-  --> $DIR/rename.rs:71:9
+  --> $DIR/rename.rs:72:9
    |
 LL | #![warn(clippy::mem_discriminant_non_enum)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `enum_intrinsics_non_enums`
 
 error: lint `clippy::panic_params` has been renamed to `non_fmt_panics`
-  --> $DIR/rename.rs:72:9
+  --> $DIR/rename.rs:73:9
    |
 LL | #![warn(clippy::panic_params)]
    |         ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `non_fmt_panics`
 
 error: lint `clippy::positional_named_format_parameters` has been renamed to `named_arguments_used_positionally`
-  --> $DIR/rename.rs:73:9
+  --> $DIR/rename.rs:74:9
    |
 LL | #![warn(clippy::positional_named_format_parameters)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `named_arguments_used_positionally`
 
 error: lint `clippy::temporary_cstring_as_ptr` has been renamed to `temporary_cstring_as_ptr`
-  --> $DIR/rename.rs:74:9
+  --> $DIR/rename.rs:75:9
    |
 LL | #![warn(clippy::temporary_cstring_as_ptr)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `temporary_cstring_as_ptr`
 
 error: lint `clippy::unknown_clippy_lints` has been renamed to `unknown_lints`
-  --> $DIR/rename.rs:75:9
+  --> $DIR/rename.rs:76:9
    |
 LL | #![warn(clippy::unknown_clippy_lints)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unknown_lints`
 
 error: lint `clippy::unused_label` has been renamed to `unused_labels`
-  --> $DIR/rename.rs:76:9
+  --> $DIR/rename.rs:77:9
    |
 LL | #![warn(clippy::unused_label)]
    |         ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unused_labels`
 
-error: aborting due to 38 previous errors
+error: aborting due to 39 previous errors
 

src/tools/rustfmt/src/items.rs

@@ -594,7 +594,7 @@ impl<'a> FmtVisitor<'a> {
             let both_type = |l: &TyOpt, r: &TyOpt| is_type(l) && is_type(r);
             let both_opaque = |l: &TyOpt, r: &TyOpt| is_opaque(l) && is_opaque(r);
             let need_empty_line = |a: &ast::AssocItemKind, b: &ast::AssocItemKind| match (a, b) {
-                (TyAlias(lty), TyAlias(rty))
+                (Type(lty), Type(rty))
                     if both_type(&lty.ty, &rty.ty) || both_opaque(&lty.ty, &rty.ty) =>
                 {
                     false
@@ -612,7 +612,7 @@ impl<'a> FmtVisitor<'a> {
             }
 
             buffer.sort_by(|(_, a), (_, b)| match (&a.kind, &b.kind) {
-                (TyAlias(lty), TyAlias(rty))
+                (Type(lty), Type(rty))
                     if both_type(&lty.ty, &rty.ty) || both_opaque(&lty.ty, &rty.ty) =>
                 {
                     a.ident.as_str().cmp(b.ident.as_str())
@@ -621,10 +621,10 @@ impl<'a> FmtVisitor<'a> {
                     a.ident.as_str().cmp(b.ident.as_str())
                 }
                 (Fn(..), Fn(..)) => a.span.lo().cmp(&b.span.lo()),
-                (TyAlias(ty), _) if is_type(&ty.ty) => Ordering::Less,
+                (Type(ty), _) if is_type(&ty.ty) => Ordering::Less,
-                (_, TyAlias(ty)) if is_type(&ty.ty) => Ordering::Greater,
+                (_, Type(ty)) if is_type(&ty.ty) => Ordering::Greater,
-                (TyAlias(..), _) => Ordering::Less,
+                (Type(..), _) => Ordering::Less,
-                (_, TyAlias(..)) => Ordering::Greater,
+                (_, Type(..)) => Ordering::Greater,
                 (Const(..), _) => Ordering::Less,
                 (_, Const(..)) => Ordering::Greater,
                 (MacCall(..), _) => Ordering::Less,

src/tools/rustfmt/src/visitor.rs

@@ -660,7 +660,7 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
                     self.push_rewrite(ai.span, rewrite);
                 }
             }
-            (ast::AssocItemKind::TyAlias(ref ty_alias), _) => {
+            (ast::AssocItemKind::Type(ref ty_alias), _) => {
                 self.visit_ty_alias_kind(ty_alias, visitor_kind, ai.span);
             }
             (ast::AssocItemKind::MacCall(ref mac), _) => {

src/tools/tidy/src/ui_tests.rs

@@ -7,8 +7,8 @@ use std::path::Path;
 
 const ENTRY_LIMIT: usize = 1000;
 // FIXME: The following limits should be reduced eventually.
-const ROOT_ENTRY_LIMIT: usize = 968;
+const ROOT_ENTRY_LIMIT: usize = 950;
-const ISSUES_ENTRY_LIMIT: usize = 2147;
+const ISSUES_ENTRY_LIMIT: usize = 2141;
 
 fn check_entries(path: &Path, bad: &mut bool) {
     let dirs = walkdir::WalkDir::new(&path.join("test/ui"))