Rollup of 6 pull requests

compiler/rustc_error_codes/src/error_codes.rs

@@ -618,7 +618,7 @@ E0791: include_str!("./error_codes/E0791.md"),
 //  E0487, // unsafe use of destructor: destructor might be called while...
 //  E0488, // lifetime of variable does not enclose its declaration
 //  E0489, // type/lifetime parameter not in scope here
-    E0490, // a value of type `..` is borrowed for too long
+//  E0490, // removed: unreachable
     E0523, // two dependencies have same (crate-name, disambiguator) but different SVH
 //  E0526, // shuffle indices are not constant
 //  E0540, // multiple rustc_deprecated attributes

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

@@ -101,7 +101,6 @@ infer_subtype_2 = ...so that {$requirement ->
 infer_reborrow = ...so that reference does not outlive borrowed content
 infer_reborrow_upvar = ...so that closure can access `{$name}`
 infer_relate_object_bound = ...so that it can be closed over into an object
-infer_data_borrowed = ...so that the type `{$name}` is not borrowed for too long
 infer_reference_outlives_referent = ...so that the reference type `{$name}` does not outlive the data it points at
 infer_relate_param_bound = ...so that the type `{$name}` will meet its required lifetime bounds{$continues ->
     [true] ...

compiler/rustc_infer/src/infer/error_reporting/note.rs

@@ -29,15 +29,6 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 RegionOriginNote::Plain { span, msg: fluent::infer_relate_object_bound }
                     .add_to_diagnostic(err);
             }
-            infer::DataBorrowed(ty, span) => {
-                RegionOriginNote::WithName {
-                    span,
-                    msg: fluent::infer_data_borrowed,
-                    name: &self.ty_to_string(ty),
-                    continues: false,
-                }
-                .add_to_diagnostic(err);
-            }
             infer::ReferenceOutlivesReferent(ty, span) => {
                 RegionOriginNote::WithName {
                     span,
@@ -227,32 +218,6 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 );
                 err
             }
-            infer::DataBorrowed(ty, span) => {
-                let mut err = struct_span_err!(
-                    self.tcx.sess,
-                    span,
-                    E0490,
-                    "a value of type `{}` is borrowed for too long",
-                    self.ty_to_string(ty)
-                );
-                note_and_explain_region(
-                    self.tcx,
-                    &mut err,
-                    "the type is valid for ",
-                    sub,
-                    "",
-                    None,
-                );
-                note_and_explain_region(
-                    self.tcx,
-                    &mut err,
-                    "but the borrow lasts for ",
-                    sup,
-                    "",
-                    None,
-                );
-                err
-            }
             infer::ReferenceOutlivesReferent(ty, span) => {
                 let mut err = struct_span_err!(
                     self.tcx.sess,

compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs

@@ -702,26 +702,8 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
                     // Obtain the spans for all the places that can
                     // influence the constraints on this value for
                     // richer diagnostics in `static_impl_trait`.
-                    let influences: Vec<Span> = self
-                        .data
-                        .constraints
-                        .iter()
-                        .filter_map(|(constraint, origin)| match (constraint, origin) {
-                            (
-                                Constraint::VarSubVar(_, sup),
-                                SubregionOrigin::DataBorrowed(_, sp),
-                            ) if sup == &node_vid => Some(*sp),
-                            _ => None,
-                        })
-                        .collect();
-
-                    self.collect_error_for_expanding_node(
-                        graph,
-                        &mut dup_vec,
-                        node_vid,
-                        errors,
-                        influences,
-                    );
+
+                    self.collect_error_for_expanding_node(graph, &mut dup_vec, node_vid, errors);
                 }
             }
         }
@@ -775,7 +757,6 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
         dup_vec: &mut IndexVec<RegionVid, Option<RegionVid>>,
         node_idx: RegionVid,
         errors: &mut Vec<RegionResolutionError<'tcx>>,
-        influences: Vec<Span>,
     ) {
         // Errors in expanding nodes result from a lower-bound that is
         // not contained by an upper-bound.
@@ -830,7 +811,7 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
                         lower_bound.region,
                         upper_bound.origin.clone(),
                         upper_bound.region,
-                        influences,
+                        vec![],
                     ));
                     return;
                 }

compiler/rustc_infer/src/infer/mod.rs

@@ -410,9 +410,6 @@ pub enum SubregionOrigin<'tcx> {
     /// Creating a pointer `b` to contents of another reference
     Reborrow(Span),
 
-    /// Data with type `Ty<'tcx>` was borrowed
-    DataBorrowed(Ty<'tcx>, Span),
-
     /// (&'a &'b T) where a >= b
     ReferenceOutlivesReferent(Ty<'tcx>, Span),
 
@@ -1978,7 +1975,6 @@ impl<'tcx> SubregionOrigin<'tcx> {
             RelateParamBound(a, ..) => a,
             RelateRegionParamBound(a) => a,
             Reborrow(a) => a,
-            DataBorrowed(_, a) => a,
             ReferenceOutlivesReferent(_, a) => a,
             CompareImplItemObligation { span, .. } => span,
             AscribeUserTypeProvePredicate(span) => span,

compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs

@@ -382,10 +382,26 @@ impl<'a> DiagnosticDeriveVariantBuilder<'a> {
                     return Ok(quote! { #diag.subdiagnostic(#binding); });
                 }
             }
-            (Meta::List(_), "subdiagnostic") => {
-                throw_invalid_attr!(attr, &meta, |diag| {
-                    diag.help("`subdiagnostic` does not support nested attributes")
-                })
+            (Meta::List(MetaList { ref nested, .. }), "subdiagnostic") => {
+                if nested.len() == 1
+                    && let Some(NestedMeta::Meta(Meta::Path(path))) = nested.first()
+                    && path.is_ident("eager") {
+                        let handler = match &self.parent.kind {
+                            DiagnosticDeriveKind::Diagnostic { handler } => handler,
+                            DiagnosticDeriveKind::LintDiagnostic => {
+                                throw_invalid_attr!(attr, &meta, |diag| {
+                                    diag.help("eager subdiagnostics are not supported on lints")
+                                })
+                            }
+                        };
+                        return Ok(quote! { #diag.eager_subdiagnostic(#handler, #binding); });
+                } else {
+                    throw_invalid_attr!(attr, &meta, |diag| {
+                        diag.help(
+                            "`eager` is the only supported nested attribute for `subdiagnostic`",
+                        )
+                    })
+                }
             }
             _ => (),
         }

compiler/rustc_macros/src/lib.rs

@@ -1,5 +1,6 @@
 #![feature(allow_internal_unstable)]
 #![feature(if_let_guard)]
+#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_span)]

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -334,6 +334,15 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         self.r.field_names.insert(def_id, field_names);
     }
 
+    fn insert_field_visibilities_local(&mut self, def_id: DefId, vdata: &ast::VariantData) {
+        let field_vis = vdata
+            .fields()
+            .iter()
+            .map(|field| field.vis.span.until(field.ident.map_or(field.ty.span, |i| i.span)))
+            .collect();
+        self.r.field_visibility_spans.insert(def_id, field_vis);
+    }
+
     fn insert_field_names_extern(&mut self, def_id: DefId) {
         let field_names =
             self.r.cstore().struct_field_names_untracked(def_id, self.r.session).collect();
@@ -737,6 +746,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
 
                 // Record field names for error reporting.
                 self.insert_field_names_local(def_id, vdata);
+                self.insert_field_visibilities_local(def_id, vdata);
 
                 // If this is a tuple or unit struct, define a name
                 // in the value namespace as well.
@@ -770,6 +780,8 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                         Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id.to_def_id());
                     self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, sp, expansion));
                     self.r.visibilities.insert(ctor_def_id, ctor_vis);
+                    // We need the field visibility spans also for the constructor for E0603.
+                    self.insert_field_visibilities_local(ctor_def_id.to_def_id(), vdata);
 
                     self.r
                         .struct_constructors
@@ -783,6 +795,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
 
                 // Record field names for error reporting.
                 self.insert_field_names_local(def_id, vdata);
+                self.insert_field_visibilities_local(def_id, vdata);
             }
 
             ItemKind::Trait(..) => {
@@ -1510,6 +1523,7 @@ impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
 
         // Record field names for error reporting.
         self.insert_field_names_local(def_id.to_def_id(), &variant.data);
+        self.insert_field_visibilities_local(def_id.to_def_id(), &variant.data);
 
         visit::walk_variant(self, variant);
     }

compiler/rustc_resolve/src/diagnostics.rs

@@ -6,7 +6,9 @@ use rustc_ast::{self as ast, Crate, ItemKind, ModKind, NodeId, Path, CRATE_NODE_
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::struct_span_err;
-use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, MultiSpan};
+use rustc_errors::{
+    pluralize, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, MultiSpan,
+};
 use rustc_feature::BUILTIN_ATTRIBUTES;
 use rustc_hir::def::Namespace::{self, *};
 use rustc_hir::def::{self, CtorKind, CtorOf, DefKind, NonMacroAttrKind, PerNS};
@@ -1604,6 +1606,16 @@ impl<'a> Resolver<'a> {
         err.span_label(ident.span, &format!("private {}", descr));
         if let Some(span) = ctor_fields_span {
             err.span_label(span, "a constructor is private if any of the fields is private");
+            if let Res::Def(_, d) = res && let Some(fields) = self.field_visibility_spans.get(&d) {
+                err.multipart_suggestion_verbose(
+                    &format!(
+                        "consider making the field{} publicly accessible",
+                        pluralize!(fields.len())
+                    ),
+                    fields.iter().map(|span| (*span, "pub ".to_string())).collect(),
+                    Applicability::MaybeIncorrect,
+                );
+            }
         }
 
         // Print the whole import chain to make it easier to see what happens.

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -1451,6 +1451,17 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                         .collect();
 
                     if non_visible_spans.len() > 0 {
+                        if let Some(fields) = self.r.field_visibility_spans.get(&def_id) {
+                            err.multipart_suggestion_verbose(
+                                &format!(
+                                    "consider making the field{} publicly accessible",
+                                    pluralize!(fields.len())
+                                ),
+                                fields.iter().map(|span| (*span, "pub ".to_string())).collect(),
+                                Applicability::MaybeIncorrect,
+                            );
+                        }
+
                         let mut m: MultiSpan = non_visible_spans.clone().into();
                         non_visible_spans
                             .into_iter()

compiler/rustc_resolve/src/lib.rs

@@ -881,6 +881,10 @@ pub struct Resolver<'a> {
     /// Used for hints during error reporting.
     field_names: FxHashMap<DefId, Vec<Spanned<Symbol>>>,
 
+    /// Span of the privacy modifier in fields of an item `DefId` accessible with dot syntax.
+    /// Used for hints during error reporting.
+    field_visibility_spans: FxHashMap<DefId, Vec<Span>>,
+
     /// All imports known to succeed or fail.
     determined_imports: Vec<&'a Import<'a>>,
 
@@ -1268,6 +1272,7 @@ impl<'a> Resolver<'a> {
 
             has_self: FxHashSet::default(),
             field_names: FxHashMap::default(),
+            field_visibility_spans: FxHashMap::default(),
 
             determined_imports: Vec::new(),
             indeterminate_imports: Vec::new(),

compiler/rustc_trait_selection/src/traits/error_reporting/method_chain.rs

@@ -55,7 +55,7 @@ impl<'a, 'tcx> TypeRelation<'tcx> for CollectAllMismatches<'a, 'tcx> {
 
     fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>> {
         self.infcx.probe(|_| {
-            if a.is_ty_infer() || b.is_ty_infer() {
+            if a.is_ty_var() || b.is_ty_var() {
                 Ok(a)
             } else {
                 self.infcx.super_combine_tys(self, a, b).or_else(|e| {
@@ -71,10 +71,13 @@ impl<'a, 'tcx> TypeRelation<'tcx> for CollectAllMismatches<'a, 'tcx> {
         a: ty::Const<'tcx>,
         b: ty::Const<'tcx>,
     ) -> RelateResult<'tcx, ty::Const<'tcx>> {
-        if a == b {
-            return Ok(a);
-        }
-        relate::super_relate_consts(self, a, b) // could do something similar here for constants!
+        self.infcx.probe(|_| {
+            if a.is_ct_infer() || b.is_ct_infer() {
+                Ok(a)
+            } else {
+                relate::super_relate_consts(self, a, b) // could do something similar here for constants!
+            }
+        })
     }
 
     fn binders<T: Relate<'tcx>>(

src/librustdoc/clean/types.rs

@@ -676,15 +676,23 @@ impl Item {
         }
         let header = match *self.kind {
             ItemKind::ForeignFunctionItem(_) => {
-                let abi = tcx.fn_sig(self.item_id.as_def_id().unwrap()).abi();
+                let def_id = self.item_id.as_def_id().unwrap();
+                let abi = tcx.fn_sig(def_id).abi();
                 hir::FnHeader {
                     unsafety: if abi == Abi::RustIntrinsic {
                         intrinsic_operation_unsafety(tcx, self.item_id.as_def_id().unwrap())
                     } else {
                         hir::Unsafety::Unsafe
                     },
                     abi,
-                    constness: hir::Constness::NotConst,
+                    constness: if abi == Abi::RustIntrinsic
+                        && tcx.is_const_fn(def_id)
+                        && is_unstable_const_fn(tcx, def_id).is_none()
+                    {
+                        hir::Constness::Const
+                    } else {
+                        hir::Constness::NotConst
+                    },
                     asyncness: hir::IsAsync::NotAsync,
                 }
             }

src/tools/tidy/src/error_codes.rs

@@ -31,10 +31,8 @@ const IGNORE_DOCTEST_CHECK: &[&str] =
     &["E0208", "E0464", "E0570", "E0601", "E0602", "E0640", "E0717"];
 
 // Error codes that don't yet have a UI test. This list will eventually be removed.
-const IGNORE_UI_TEST_CHECK: &[&str] = &[
-    "E0461", "E0465", "E0476", "E0490", "E0514", "E0523", "E0554", "E0640", "E0717", "E0729",
-    "E0789",
-];
+const IGNORE_UI_TEST_CHECK: &[&str] =
+    &["E0461", "E0465", "E0476", "E0514", "E0523", "E0554", "E0640", "E0717", "E0729", "E0789"];
 
 macro_rules! verbose_print {
     ($verbose:expr, $($fmt:tt)*) => {

tests/rustdoc/const-intrinsic.rs

@@ -0,0 +1,25 @@
+#![feature(intrinsics)]
+#![feature(staged_api)]
+
+#![crate_name = "foo"]
+#![stable(since="1.0.0", feature="rust1")]
+
+extern "rust-intrinsic" {
+    // @has 'foo/fn.transmute.html'
+    // @has - '//pre[@class="rust fn"]' 'pub const unsafe extern "rust-intrinsic" fn transmute<T, U>(_: T) -> U'
+    #[stable(since="1.0.0", feature="rust1")]
+    #[rustc_const_stable(feature = "const_transmute", since = "1.56.0")]
+    pub fn transmute<T, U>(_: T) -> U;
+
+    // @has 'foo/fn.unreachable.html'
+    // @has - '//pre[@class="rust fn"]' 'pub unsafe extern "rust-intrinsic" fn unreachable() -> !'
+    #[stable(since="1.0.0", feature="rust1")]
+    pub fn unreachable() -> !;
+}
+
+extern "C" {
+    // @has 'foo/fn.needs_drop.html'
+    // @has - '//pre[@class="rust fn"]' 'pub unsafe extern "C" fn needs_drop() -> !'
+    #[stable(since="1.0.0", feature="rust1")]
+    pub fn needs_drop() -> !;
+}

tests/ui-fulldeps/session-diagnostic/diagnostic-derive.rs

@@ -723,7 +723,6 @@ struct SubdiagnosticEagerLint {
 #[diag(compiletest_example)]
 struct SubdiagnosticEagerCorrect {
     #[subdiagnostic(eager)]
-    //~^ ERROR `#[subdiagnostic(...)]` is not a valid attribute
     note: Note,
 }
 
@@ -744,7 +743,6 @@ pub(crate) struct SubdiagnosticWithSuggestion {
 #[diag(compiletest_example)]
 struct SubdiagnosticEagerSuggestion {
     #[subdiagnostic(eager)]
-    //~^ ERROR `#[subdiagnostic(...)]` is not a valid attribute
     sub: SubdiagnosticWithSuggestion,
 }