Auto merge of #2738 - RalfJung:rustup, r=RalfJung

Rustup

8 files changed, 107 insertions, 17 deletions

diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index 43862570e80..d6de6e70ead 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -25,6 +25,7 @@ use crate::{
     types::{transparent_newtype_field, CItemKind},
     EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext,
 };
+use hir::IsAsync;
 use rustc_ast::attr;
 use rustc_ast::tokenstream::{TokenStream, TokenTree};
 use rustc_ast::visit::{FnCtxt, FnKind};
@@ -40,7 +41,10 @@ use rustc_feature::{deprecated_attributes, AttributeGate, BuiltinAttribute, Gate
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
-use rustc_hir::{ForeignItemKind, GenericParamKind, HirId, Node, PatKind, PredicateOrigin};
+use rustc_hir::intravisit::FnKind as HirFnKind;
+use rustc_hir::{
+    Body, FnDecl, ForeignItemKind, GenericParamKind, HirId, Node, PatKind, PredicateOrigin,
+};
 use rustc_index::vec::Idx;
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::layout::{LayoutError, LayoutOf};
@@ -270,7 +274,7 @@ impl<'tcx> LateLintPass<'tcx> for NonShorthandFieldPatterns {
                             |lint| {
                                 let suggested_ident =
                                     format!("{}{}", binding_annot.prefix_str(), ident);
-                                lint.set_arg("ident", ident.clone()).span_suggestion(
+                                lint.set_arg("ident", ident).span_suggestion(
                                     fieldpat.span,
                                     fluent::suggestion,
                                     suggested_ident,
@@ -1371,6 +1375,72 @@ impl<'tcx> LateLintPass<'tcx> for UnstableFeatures {
 }
 
 declare_lint! {
+    /// The `ungated_async_fn_track_caller` lint warns when the
+    /// `#[track_caller]` attribute is used on an async function, method, or
+    /// closure, without enabling the corresponding unstable feature flag.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// #[track_caller]
+    /// async fn foo() {}
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// The attribute must be used in conjunction with the
+    /// [`closure_track_caller` feature flag]. Otherwise, the `#[track_caller]`
+    /// annotation will function as as no-op.
+    ///
+    /// [`closure_track_caller` feature flag]: https://doc.rust-lang.org/beta/unstable-book/language-features/closure-track-caller.html
+    UNGATED_ASYNC_FN_TRACK_CALLER,
+    Warn,
+    "enabling track_caller on an async fn is a no-op unless the closure_track_caller feature is enabled"
+}
+
+declare_lint_pass!(
+    /// Explains corresponding feature flag must be enabled for the `#[track_caller] attribute to
+    /// do anything
+    UngatedAsyncFnTrackCaller => [UNGATED_ASYNC_FN_TRACK_CALLER]
+);
+
+impl<'tcx> LateLintPass<'tcx> for UngatedAsyncFnTrackCaller {
+    fn check_fn(
+        &mut self,
+        cx: &LateContext<'_>,
+        fn_kind: HirFnKind<'_>,
+        _: &'tcx FnDecl<'_>,
+        _: &'tcx Body<'_>,
+        span: Span,
+        hir_id: HirId,
+    ) {
+        if fn_kind.asyncness() == IsAsync::Async
+            && !cx.tcx.features().closure_track_caller
+            && let attrs = cx.tcx.hir().attrs(hir_id)
+            // Now, check if the function has the `#[track_caller]` attribute
+            && let Some(attr) = attrs.iter().find(|attr| attr.has_name(sym::track_caller))
+            {
+                cx.struct_span_lint(
+                    UNGATED_ASYNC_FN_TRACK_CALLER,
+                    attr.span,
+                    fluent::lint_ungated_async_fn_track_caller,
+                    |lint| {
+                        lint.span_label(span, fluent::label);
+                        rustc_session::parse::add_feature_diagnostics(
+                            lint,
+                            &cx.tcx.sess.parse_sess,
+                            sym::closure_track_caller,
+                        );
+                        lint
+                    },
+                );
+            }
+    }
+}
+
+declare_lint! {
     /// The `unreachable_pub` lint triggers for `pub` items not reachable from
     /// the crate root.
     ///
@@ -2052,7 +2122,7 @@ impl KeywordIdents {
             ident.span,
             fluent::lint_builtin_keyword_idents,
             |lint| {
-                lint.set_arg("kw", ident.clone()).set_arg("next", next_edition).span_suggestion(
+                lint.set_arg("kw", ident).set_arg("next", next_edition).span_suggestion(
                     ident.span,
                     fluent::suggestion,
                     format!("r#{}", ident),
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
index 40b2588388d..3c9ad410663 100644
--- a/compiler/rustc_lint/src/context.rs
+++ b/compiler/rustc_lint/src/context.rs
@@ -438,18 +438,18 @@ impl LintStore {
                         return CheckLintNameResult::Tool(Ok(&lint_ids));
                     }
                 },
-                Some(&Id(ref id)) => return CheckLintNameResult::Tool(Ok(slice::from_ref(id))),
+                Some(Id(id)) => return CheckLintNameResult::Tool(Ok(slice::from_ref(id))),
                 // If the lint was registered as removed or renamed by the lint tool, we don't need
                 // to treat tool_lints and rustc lints different and can use the code below.
                 _ => {}
             }
         }
         match self.by_name.get(&complete_name) {
-            Some(&Renamed(ref new_name, _)) => CheckLintNameResult::Warning(
+            Some(Renamed(new_name, _)) => CheckLintNameResult::Warning(
                 format!("lint `{}` has been renamed to `{}`", complete_name, new_name),
                 Some(new_name.to_owned()),
             ),
-            Some(&Removed(ref reason)) => CheckLintNameResult::Warning(
+            Some(Removed(reason)) => CheckLintNameResult::Warning(
                 format!("lint `{}` has been removed: {}", complete_name, reason),
                 None,
             ),
@@ -470,7 +470,7 @@ impl LintStore {
                     CheckLintNameResult::Ok(&lint_ids)
                 }
             },
-            Some(&Id(ref id)) => CheckLintNameResult::Ok(slice::from_ref(id)),
+            Some(Id(id)) => CheckLintNameResult::Ok(slice::from_ref(id)),
             Some(&Ignored) => CheckLintNameResult::Ok(&[]),
         }
     }
@@ -483,7 +483,16 @@ impl LintStore {
             return CheckLintNameResult::NoLint(Some(Symbol::intern(&name_lower)));
         }
         // ...if not, search for lints with a similar name
-        let groups = self.lint_groups.keys().copied().map(Symbol::intern);
+        // Note: find_best_match_for_name depends on the sort order of its input vector.
+        // To ensure deterministic output, sort elements of the lint_groups hash map.
+        // Also, never suggest deprecated lint groups.
+        let mut groups: Vec<_> = self
+            .lint_groups
+            .iter()
+            .filter_map(|(k, LintGroup { depr, .. })| if depr.is_none() { Some(k) } else { None })
+            .collect();
+        groups.sort();
+        let groups = groups.iter().map(|k| Symbol::intern(k));
         let lints = self.lints.iter().map(|l| Symbol::intern(&l.name_lower()));
         let names: Vec<Symbol> = groups.chain(lints).collect();
         let suggestion = find_best_match_for_name(&names, Symbol::intern(&name_lower), None);
@@ -513,7 +522,7 @@ impl LintStore {
                     CheckLintNameResult::Tool(Err((Some(&lint_ids), complete_name)))
                 }
             },
-            Some(&Id(ref id)) => {
+            Some(Id(id)) => {
                 CheckLintNameResult::Tool(Err((Some(slice::from_ref(id)), complete_name)))
             }
             Some(other) => {
diff --git a/compiler/rustc_lint/src/for_loops_over_fallibles.rs b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
index 4187850153c..182734fa9fc 100644
--- a/compiler/rustc_lint/src/for_loops_over_fallibles.rs
+++ b/compiler/rustc_lint/src/for_loops_over_fallibles.rs
@@ -71,11 +71,11 @@ impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles {
                 );
             } else {
                 lint.multipart_suggestion_verbose(
-                    format!("to check pattern in a loop use `while let`"),
+                    "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!(") = ")),
+                        (pat.span.between(arg.span), ") = ".to_string()),
                     ],
                     Applicability::MaybeIncorrect
                 );
@@ -95,7 +95,7 @@ impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles {
                 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!(") = ")),
+                    (pat.span.between(arg.span), ") = ".to_string()),
                 ],
                 Applicability::MaybeIncorrect,
             )
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 847c356b83c..e9d3d44a3f9 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -39,9 +39,9 @@ struct LintLevelSets {
 }
 
 rustc_index::newtype_index! {
+    #[custom_encodable] // we don't need encoding
     struct LintStackIndex {
-        ENCODABLE = custom, // we don't need encoding
-        const COMMAND_LINE = 0,
+        const COMMAND_LINE = 0;
     }
 }
 
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index 11022eb80ea..1275d6f223c 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -219,6 +219,7 @@ late_lint_methods!(
             // May Depend on constants elsewhere
             UnusedBrokenConst: UnusedBrokenConst,
             UnstableFeatures: UnstableFeatures,
+            UngatedAsyncFnTrackCaller: UngatedAsyncFnTrackCaller,
             ArrayIntoIter: ArrayIntoIter::default(),
             DropTraitConstraints: DropTraitConstraints,
             TemporaryCStringAsPtr: TemporaryCStringAsPtr,
diff --git a/compiler/rustc_lint/src/non_fmt_panic.rs b/compiler/rustc_lint/src/non_fmt_panic.rs
index c1820ac4d1e..8dccfe0046c 100644
--- a/compiler/rustc_lint/src/non_fmt_panic.rs
+++ b/compiler/rustc_lint/src/non_fmt_panic.rs
@@ -304,7 +304,7 @@ fn check_panic_str<'tcx>(
 
 /// Given the span of `some_macro!(args);`, gives the span of `(` and `)`,
 /// and the type of (opening) delimiter used.
-fn find_delimiters<'tcx>(cx: &LateContext<'tcx>, span: Span) -> Option<(Span, Span, char)> {
+fn find_delimiters(cx: &LateContext<'_>, span: Span) -> Option<(Span, Span, char)> {
     let snippet = cx.sess().parse_sess.source_map().span_to_snippet(span).ok()?;
     let (open, open_ch) = snippet.char_indices().find(|&(_, c)| "([{".contains(c))?;
     let close = snippet.rfind(|c| ")]}".contains(c))?;
diff --git a/compiler/rustc_lint/src/nonstandard_style.rs b/compiler/rustc_lint/src/nonstandard_style.rs
index 7e50801f80c..91fcd6d690e 100644
--- a/compiler/rustc_lint/src/nonstandard_style.rs
+++ b/compiler/rustc_lint/src/nonstandard_style.rs
@@ -175,13 +175,23 @@ impl EarlyLintPass for NonCamelCaseTypes {
             return;
         }
 
-        match it.kind {
+        match &it.kind {
             ast::ItemKind::TyAlias(..)
             | ast::ItemKind::Enum(..)
             | ast::ItemKind::Struct(..)
             | ast::ItemKind::Union(..) => self.check_case(cx, "type", &it.ident),
             ast::ItemKind::Trait(..) => self.check_case(cx, "trait", &it.ident),
             ast::ItemKind::TraitAlias(..) => self.check_case(cx, "trait alias", &it.ident),
+
+            // N.B. This check is only for inherent associated types, so that we don't lint against
+            // trait impls where we should have warned for the trait definition already.
+            ast::ItemKind::Impl(box ast::Impl { of_trait: None, items, .. }) => {
+                for it in items {
+                    if let ast::AssocItemKind::Type(..) = it.kind {
+                        self.check_case(cx, "associated type", &it.ident);
+                    }
+                }
+            }
             _ => (),
         }
     }
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index d628a18dd01..3b8df61a0ea 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -1279,7 +1279,7 @@ impl UnusedImportBraces {
     fn check_use_tree(&self, cx: &EarlyContext<'_>, use_tree: &ast::UseTree, item: &ast::Item) {
         if let ast::UseTreeKind::Nested(ref items) = use_tree.kind {
             // Recursively check nested UseTrees
-            for &(ref tree, _) in items {
+            for (tree, _) in items {
                 self.check_use_tree(cx, tree, item);
             }