Auto merge of #100346 - matthiaskrgr:rollup-6rljn4p, r=matthiaskrgr

Rollup of 14 pull requests

Successful merges:

 - #98775 (rustdoc: improve scroll locking in the rustdoc mobile sidebars)
 - #99479 (rustdoc-json: Remove doc FIXME for Import::id and explain)
 - #100040 (Error on broken pipe but do not backtrace or ICE)
 - #100072 (linker-plugin-lto.md: Correct the name of example c file)
 - #100098 (Some "this expression has a field"-related fixes)
 - #100226 (Do not manually craft a span pointing inside a multibyte character.)
 - #100240 (Fail gracefully when const pattern is not structural match.)
 - #100256 (Add some high-level docs to `FnCtxt` and `ItemCtxt`)
 - #100261 (Set tainted errors bit before emitting coerce suggestions.)
 - #100275 (also update anyhow in codegen_cranelift)
 - #100281 (Remove more Clean trait implementations)
 - #100314 (Mention `unit-test` in MIR opt test README)
 - #100319 (Remove more Clean trait implementations)
 - #100323 ([rustdoc] Don't render impl blocks with doc comment if they only contain private items by default)

Failed merges:

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

9 files changed, 149 insertions, 83 deletions

diff --git a/compiler/rustc_codegen_cranelift/Cargo.lock b/compiler/rustc_codegen_cranelift/Cargo.lock
index 532049c858d..402fbb16f97 100644
--- a/compiler/rustc_codegen_cranelift/Cargo.lock
+++ b/compiler/rustc_codegen_cranelift/Cargo.lock
@@ -15,9 +15,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.56"
+version = "1.0.60"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4361135be9122e0870de935d7c439aef945b9f9ddd4199a553b5270b49c82a27"
+checksum = "c794e162a5eff65c72ef524dfe393eb923c354e350bb78b9c7383df13f3bc142"
 
 [[package]]
 name = "ar"
diff --git a/compiler/rustc_driver/src/lib.rs b/compiler/rustc_driver/src/lib.rs
index 53ae913f94f..94639bf8e1e 100644
--- a/compiler/rustc_driver/src/lib.rs
+++ b/compiler/rustc_driver/src/lib.rs
@@ -1148,6 +1148,17 @@ static DEFAULT_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send +
     LazyLock::new(|| {
         let hook = panic::take_hook();
         panic::set_hook(Box::new(|info| {
+            // If the error was caused by a broken pipe then this is not a bug.
+            // Write the error and return immediately. See #98700.
+            #[cfg(windows)]
+            if let Some(msg) = info.payload().downcast_ref::<String>() {
+                if msg.starts_with("failed printing to stdout: ") && msg.ends_with("(os error 232)")
+                {
+                    early_error_no_abort(ErrorOutputType::default(), &msg);
+                    return;
+                }
+            };
+
             // Invoke the default handler, which prints the actual panic message and optionally a backtrace
             (*DEFAULT_HOOK)(info);
 
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index b6cf182916c..4e7ba1c6ce4 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -11,7 +11,7 @@ use rustc_middle::ty::adjustment;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::symbol::Symbol;
 use rustc_span::symbol::{kw, sym};
-use rustc_span::{BytePos, Span, DUMMY_SP};
+use rustc_span::{BytePos, Span};
 
 declare_lint! {
     /// The `unused_must_use` lint detects unused result of a type flagged as
@@ -504,23 +504,23 @@ trait UnusedDelimLint {
             ast::ExprKind::Block(ref block, None) if block.stmts.len() > 0 => {
                 let start = block.stmts[0].span;
                 let end = block.stmts[block.stmts.len() - 1].span;
-                if value.span.from_expansion() || start.from_expansion() || end.from_expansion() {
-                    (
-                        value.span.with_hi(value.span.lo() + BytePos(1)),
-                        value.span.with_lo(value.span.hi() - BytePos(1)),
-                    )
+                if let Some(start) = start.find_ancestor_inside(value.span)
+                    && let Some(end) = end.find_ancestor_inside(value.span)
+                {
+                    Some((
+                        value.span.with_hi(start.lo()),
+                        value.span.with_lo(end.hi()),
+                    ))
                 } else {
-                    (value.span.with_hi(start.lo()), value.span.with_lo(end.hi()))
+                    None
                 }
             }
             ast::ExprKind::Paren(ref expr) => {
-                if value.span.from_expansion() || expr.span.from_expansion() {
-                    (
-                        value.span.with_hi(value.span.lo() + BytePos(1)),
-                        value.span.with_lo(value.span.hi() - BytePos(1)),
-                    )
+                let expr_span = expr.span.find_ancestor_inside(value.span);
+                if let Some(expr_span) = expr_span {
+                    Some((value.span.with_hi(expr_span.lo()), value.span.with_lo(expr_span.hi())))
                 } else {
-                    (value.span.with_hi(expr.span.lo()), value.span.with_lo(expr.span.hi()))
+                    None
                 }
             }
             _ => return,
@@ -529,36 +529,38 @@ trait UnusedDelimLint {
             left_pos.map_or(false, |s| s >= value.span.lo()),
             right_pos.map_or(false, |s| s <= value.span.hi()),
         );
-        self.emit_unused_delims(cx, spans, ctx.into(), keep_space);
+        self.emit_unused_delims(cx, value.span, spans, ctx.into(), keep_space);
     }
 
     fn emit_unused_delims(
         &self,
         cx: &EarlyContext<'_>,
-        spans: (Span, Span),
+        value_span: Span,
+        spans: Option<(Span, Span)>,
         msg: &str,
         keep_space: (bool, bool),
     ) {
-        // FIXME(flip1995): Quick and dirty fix for #70814. This should be fixed in rustdoc
-        // properly.
-        if spans.0 == DUMMY_SP || spans.1 == DUMMY_SP {
-            return;
-        }
-
-        cx.struct_span_lint(self.lint(), MultiSpan::from(vec![spans.0, spans.1]), |lint| {
-            let replacement = vec![
-                (spans.0, if keep_space.0 { " ".into() } else { "".into() }),
-                (spans.1, if keep_space.1 { " ".into() } else { "".into() }),
-            ];
-            lint.build(fluent::lint::unused_delim)
-                .set_arg("delim", Self::DELIM_STR)
-                .set_arg("item", msg)
-                .multipart_suggestion(
+        let primary_span = if let Some((lo, hi)) = spans {
+            MultiSpan::from(vec![lo, hi])
+        } else {
+            MultiSpan::from(value_span)
+        };
+        cx.struct_span_lint(self.lint(), primary_span, |lint| {
+            let mut db = lint.build(fluent::lint::unused_delim);
+            db.set_arg("delim", Self::DELIM_STR);
+            db.set_arg("item", msg);
+            if let Some((lo, hi)) = spans {
+                let replacement = vec![
+                    (lo, if keep_space.0 { " ".into() } else { "".into() }),
+                    (hi, if keep_space.1 { " ".into() } else { "".into() }),
+                ];
+                db.multipart_suggestion(
                     fluent::lint::suggestion,
                     replacement,
                     Applicability::MachineApplicable,
-                )
-                .emit();
+                );
+            }
+            db.emit();
         });
     }
 
@@ -766,15 +768,12 @@ impl UnusedParens {
                 // Otherwise proceed with linting.
                 _ => {}
             }
-            let spans = if value.span.from_expansion() || inner.span.from_expansion() {
-                (
-                    value.span.with_hi(value.span.lo() + BytePos(1)),
-                    value.span.with_lo(value.span.hi() - BytePos(1)),
-                )
+            let spans = if let Some(inner) = inner.span.find_ancestor_inside(value.span) {
+                Some((value.span.with_hi(inner.lo()), value.span.with_lo(inner.hi())))
             } else {
-                (value.span.with_hi(inner.span.lo()), value.span.with_lo(inner.span.hi()))
+                None
             };
-            self.emit_unused_delims(cx, spans, "pattern", (false, false));
+            self.emit_unused_delims(cx, value.span, spans, "pattern", (false, false));
         }
     }
 }
@@ -879,15 +878,12 @@ impl EarlyLintPass for UnusedParens {
                     );
                 }
                 _ => {
-                    let spans = if ty.span.from_expansion() || r.span.from_expansion() {
-                        (
-                            ty.span.with_hi(ty.span.lo() + BytePos(1)),
-                            ty.span.with_lo(ty.span.hi() - BytePos(1)),
-                        )
+                    let spans = if let Some(r) = r.span.find_ancestor_inside(ty.span) {
+                        Some((ty.span.with_hi(r.lo()), ty.span.with_lo(r.hi())))
                     } else {
-                        (ty.span.with_hi(r.span.lo()), ty.span.with_lo(r.span.hi()))
+                        None
                     };
-                    self.emit_unused_delims(cx, spans, "type", (false, false));
+                    self.emit_unused_delims(cx, ty.span, spans, "type", (false, false));
                 }
             }
         }
diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
index d6dd0f01794..f2045ac19ca 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
@@ -168,7 +168,12 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> {
         // once indirect_structural_match is a full fledged error, this
         // level of indirection can be eliminated
 
-        let inlined_const_as_pat = self.recur(cv, mir_structural_match_violation).unwrap();
+        let inlined_const_as_pat =
+            self.recur(cv, mir_structural_match_violation).unwrap_or_else(|_| Pat {
+                span: self.span,
+                ty: cv.ty(),
+                kind: Box::new(PatKind::Constant { value: cv }),
+            });
 
         if self.include_lint_checks && !self.saw_const_match_error.get() {
             // If we were able to successfully convert the const to some pat,
diff --git a/compiler/rustc_typeck/src/check/coercion.rs b/compiler/rustc_typeck/src/check/coercion.rs
index 540a8c3a83d..49dc5532abd 100644
--- a/compiler/rustc_typeck/src/check/coercion.rs
+++ b/compiler/rustc_typeck/src/check/coercion.rs
@@ -1479,6 +1479,10 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                 }
             }
             Err(coercion_error) => {
+                // Mark that we've failed to coerce the types here to suppress
+                // any superfluous errors we might encounter while trying to
+                // emit or provide suggestions on how to fix the initial error.
+                fcx.set_tainted_by_errors();
                 let (expected, found) = if label_expression_as_expected {
                     // In the case where this is a "forced unit", like
                     // `break`, we want to call the `()` "expected"
diff --git a/compiler/rustc_typeck/src/check/expr.rs b/compiler/rustc_typeck/src/check/expr.rs
index fb78632069e..a685add7f56 100644
--- a/compiler/rustc_typeck/src/check/expr.rs
+++ b/compiler/rustc_typeck/src/check/expr.rs
@@ -2526,15 +2526,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         );
 
         // try to add a suggestion in case the field is a nested field of a field of the Adt
-        if let Some((fields, substs)) = self.get_field_candidates(span, expr_t) {
-            for candidate_field in fields.iter() {
+        let mod_id = self.tcx.parent_module(id).to_def_id();
+        if let Some((fields, substs)) =
+            self.get_field_candidates_considering_privacy(span, expr_t, mod_id)
+        {
+            for candidate_field in fields {
                 if let Some(mut field_path) = self.check_for_nested_field_satisfying(
                     span,
                     &|candidate_field, _| candidate_field.ident(self.tcx()) == field,
                     candidate_field,
                     substs,
                     vec![],
-                    self.tcx.parent_module(id).to_def_id(),
+                    mod_id,
                 ) {
                     // field_path includes `field` that we're looking for, so pop it.
                     field_path.pop();
@@ -2558,22 +2561,33 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         err
     }
 
-    pub(crate) fn get_field_candidates(
+    pub(crate) fn get_field_candidates_considering_privacy(
         &self,
         span: Span,
-        base_t: Ty<'tcx>,
-    ) -> Option<(&[ty::FieldDef], SubstsRef<'tcx>)> {
-        debug!("get_field_candidates(span: {:?}, base_t: {:?}", span, base_t);
+        base_ty: Ty<'tcx>,
+        mod_id: DefId,
+    ) -> Option<(impl Iterator<Item = &'tcx ty::FieldDef> + 'tcx, SubstsRef<'tcx>)> {
+        debug!("get_field_candidates(span: {:?}, base_t: {:?}", span, base_ty);
 
-        for (base_t, _) in self.autoderef(span, base_t) {
+        for (base_t, _) in self.autoderef(span, base_ty) {
             match base_t.kind() {
                 ty::Adt(base_def, substs) if !base_def.is_enum() => {
+                    let tcx = self.tcx;
                     let fields = &base_def.non_enum_variant().fields;
-                    // For compile-time reasons put a limit on number of fields we search
-                    if fields.len() > 100 {
-                        return None;
+                    // Some struct, e.g. some that impl `Deref`, have all private fields
+                    // because you're expected to deref them to access the _real_ fields.
+                    // This, for example, will help us suggest accessing a field through a `Box<T>`.
+                    if fields.iter().all(|field| !field.vis.is_accessible_from(mod_id, tcx)) {
+                        continue;
                     }
-                    return Some((fields, substs));
+                    return Some((
+                        fields
+                            .iter()
+                            .filter(move |field| field.vis.is_accessible_from(mod_id, tcx))
+                            // For compile-time reasons put a limit on number of fields we search
+                            .take(100),
+                        substs,
+                    ));
                 }
                 _ => {}
             }
@@ -2590,7 +2604,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         candidate_field: &ty::FieldDef,
         subst: SubstsRef<'tcx>,
         mut field_path: Vec<Ident>,
-        id: DefId,
+        mod_id: DefId,
     ) -> Option<Vec<Ident>> {
         debug!(
             "check_for_nested_field_satisfying(span: {:?}, candidate_field: {:?}, field_path: {:?}",
@@ -2602,24 +2616,24 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // up to a depth of three
             None
         } else {
-            // recursively search fields of `candidate_field` if it's a ty::Adt
             field_path.push(candidate_field.ident(self.tcx).normalize_to_macros_2_0());
             let field_ty = candidate_field.ty(self.tcx, subst);
-            if let Some((nested_fields, subst)) = self.get_field_candidates(span, field_ty) {
-                for field in nested_fields.iter() {
-                    if field.vis.is_accessible_from(id, self.tcx) {
-                        if matches(candidate_field, field_ty) {
-                            return Some(field_path);
-                        } else if let Some(field_path) = self.check_for_nested_field_satisfying(
-                            span,
-                            matches,
-                            field,
-                            subst,
-                            field_path.clone(),
-                            id,
-                        ) {
-                            return Some(field_path);
-                        }
+            if matches(candidate_field, field_ty) {
+                return Some(field_path);
+            } else if let Some((nested_fields, subst)) =
+                self.get_field_candidates_considering_privacy(span, field_ty, mod_id)
+            {
+                // recursively search fields of `candidate_field` if it's a ty::Adt
+                for field in nested_fields {
+                    if let Some(field_path) = self.check_for_nested_field_satisfying(
+                        span,
+                        matches,
+                        field,
+                        subst,
+                        field_path.clone(),
+                        mod_id,
+                    ) {
+                        return Some(field_path);
                     }
                 }
             }
diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs b/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs
index 05bcc710e16..e008d50aa51 100644
--- a/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs
+++ b/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs
@@ -26,6 +26,17 @@ use rustc_trait_selection::traits::{ObligationCause, ObligationCauseCode};
 use std::cell::{Cell, RefCell};
 use std::ops::Deref;
 
+/// The `FnCtxt` stores type-checking context needed to type-check bodies of
+/// functions, closures, and `const`s, including performing type inference
+/// with [`InferCtxt`].
+///
+/// This is in contrast to [`ItemCtxt`], which is used to type-check item *signatures*
+/// and thus does not perform type inference.
+///
+/// See [`ItemCtxt`]'s docs for more.
+///
+/// [`ItemCtxt`]: crate::collect::ItemCtxt
+/// [`InferCtxt`]: infer::InferCtxt
 pub struct FnCtxt<'a, 'tcx> {
     pub(super) body_id: hir::HirId,
 
diff --git a/compiler/rustc_typeck/src/check/method/suggest.rs b/compiler/rustc_typeck/src/check/method/suggest.rs
index c92b93cbc22..f73d0fbb277 100644
--- a/compiler/rustc_typeck/src/check/method/suggest.rs
+++ b/compiler/rustc_typeck/src/check/method/suggest.rs
@@ -1000,7 +1000,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     label_span_not_found(&mut err);
                 }
 
-                self.check_for_field_method(&mut err, source, span, actual, item_name);
+                // Don't suggest (for example) `expr.field.method()` if `expr.method()`
+                // doesn't exist due to unsatisfied predicates.
+                if unsatisfied_predicates.is_empty() {
+                    self.check_for_field_method(&mut err, source, span, actual, item_name);
+                }
 
                 self.check_for_unwrap_self(&mut err, source, span, actual, item_name);
 
@@ -1334,10 +1338,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         item_name: Ident,
     ) {
         if let SelfSource::MethodCall(expr) = source
-            && let Some((fields, substs)) = self.get_field_candidates(span, actual)
+            && let mod_id = self.tcx.parent_module(expr.hir_id).to_def_id()
+            && let Some((fields, substs)) = self.get_field_candidates_considering_privacy(span, actual, mod_id)
         {
             let call_expr = self.tcx.hir().expect_expr(self.tcx.hir().get_parent_node(expr.hir_id));
-            for candidate_field in fields.iter() {
+            for candidate_field in fields {
                 if let Some(field_path) = self.check_for_nested_field_satisfying(
                     span,
                     &|_, field_ty| {
@@ -1353,7 +1358,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     candidate_field,
                     substs,
                     vec![],
-                    self.tcx.parent_module(expr.hir_id).to_def_id(),
+                    mod_id,
                 ) {
                     let field_path_str = field_path
                         .iter()
diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index 99996e80c9c..e7c5ecc60ec 100644
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -94,7 +94,27 @@ pub fn provide(providers: &mut Providers) {
 ///////////////////////////////////////////////////////////////////////////
 
 /// Context specific to some particular item. This is what implements
-/// `AstConv`. It has information about the predicates that are defined
+/// [`AstConv`].
+///
+/// # `ItemCtxt` vs `FnCtxt`
+///
+/// `ItemCtxt` is primarily used to type-check item signatures and lower them
+/// from HIR to their [`ty::Ty`] representation, which is exposed using [`AstConv`].
+/// It's also used for the bodies of items like structs where the body (the fields)
+/// are just signatures.
+///
+/// This is in contrast to [`FnCtxt`], which is used to type-check bodies of
+/// functions, closures, and `const`s -- anywhere that expressions and statements show up.
+///
+/// An important thing to note is that `ItemCtxt` does no inference -- it has no [`InferCtxt`] --
+/// while `FnCtxt` does do inference.
+///
+/// [`FnCtxt`]: crate::check::FnCtxt
+/// [`InferCtxt`]: rustc_infer::infer::InferCtxt
+///
+/// # Trait predicates
+///
+/// `ItemCtxt` has information about the predicates that are defined
 /// on the trait. Unfortunately, this predicate information is
 /// available in various different forms at various points in the
 /// process. So we can't just store a pointer to e.g., the AST or the