Rollup merge of #105500 - oli-obk:unhide_unknown_spans, r=estebank

Make some diagnostics not depend on the source of what they reference being available

r? `@estebank`

follow up to #104449

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -1059,17 +1059,12 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     );
                     if self.fn_self_span_reported.insert(fn_span) {
                         err.span_note(
-                            // Check whether the source is accessible
-                            if self.infcx.tcx.sess.source_map().is_span_accessible(self_arg.span) {
-                                self_arg.span
-                            } else {
-                                fn_call_span
-                            },
+                            self_arg.span,
                             "calling this operator moves the left-hand side",
                         );
                     }
                 }
-                CallKind::Normal { self_arg, desugaring, is_option_or_result } => {
+                CallKind::Normal { self_arg, desugaring, method_did } => {
                     let self_arg = self_arg.unwrap();
                     if let Some((CallDesugaringKind::ForLoopIntoIter, _)) = desugaring {
                         let ty = moved_place.ty(self.body, self.infcx.tcx).ty;
@@ -1139,14 +1134,27 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                             ),
                         );
                     }
+                    let tcx = self.infcx.tcx;
                     // Avoid pointing to the same function in multiple different
                     // error messages.
                     if span != DUMMY_SP && self.fn_self_span_reported.insert(self_arg.span) {
+                        let func = tcx.def_path_str(method_did);
                         err.span_note(
                             self_arg.span,
-                            &format!("this function takes ownership of the receiver `self`, which moves {}", place_name)
+                            &format!("`{func}` takes ownership of the receiver `self`, which moves {place_name}")
                         );
                     }
+                    let parent_did = tcx.parent(method_did);
+                    let parent_self_ty = (tcx.def_kind(parent_did)
+                        == rustc_hir::def::DefKind::Impl)
+                        .then_some(parent_did)
+                        .and_then(|did| match tcx.type_of(did).kind() {
+                            ty::Adt(def, ..) => Some(def.did()),
+                            _ => None,
+                        });
+                    let is_option_or_result = parent_self_ty.map_or(false, |def_id| {
+                        matches!(tcx.get_diagnostic_name(def_id), Some(sym::Option | sym::Result))
+                    });
                     if is_option_or_result && maybe_reinitialized_locations_is_empty {
                         err.span_label(
                             var_span,

compiler/rustc_const_eval/src/util/call_kind.rs

@@ -5,7 +5,7 @@
 use rustc_hir::def_id::DefId;
 use rustc_hir::{lang_items, LangItem};
 use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, AssocItemContainer, DefIdTree, Instance, ParamEnv, Ty, TyCtxt};
+use rustc_middle::ty::{AssocItemContainer, Instance, ParamEnv, Ty, TyCtxt};
 use rustc_span::symbol::Ident;
 use rustc_span::{sym, DesugaringKind, Span};
 
@@ -39,9 +39,7 @@ pub enum CallKind<'tcx> {
     Normal {
         self_arg: Option<Ident>,
         desugaring: Option<(CallDesugaringKind, Ty<'tcx>)>,
-        /// Whether the self type of the method call has an `.as_ref()` method.
-        /// Used for better diagnostics.
-        is_option_or_result: bool,
+        method_did: DefId,
     },
     /// A call to `Fn(..)::call(..)`, desugared from `my_closure(a, b, c)`
     FnCall { fn_trait_id: DefId, self_ty: Ty<'tcx> },
@@ -133,16 +131,6 @@ pub fn call_kind<'tcx>(
         } else {
             None
         };
-        let parent_did = tcx.parent(method_did);
-        let parent_self_ty = (tcx.def_kind(parent_did) == rustc_hir::def::DefKind::Impl)
-            .then_some(parent_did)
-            .and_then(|did| match tcx.type_of(did).kind() {
-                ty::Adt(def, ..) => Some(def.did()),
-                _ => None,
-            });
-        let is_option_or_result = parent_self_ty.map_or(false, |def_id| {
-            matches!(tcx.get_diagnostic_name(def_id), Some(sym::Option | sym::Result))
-        });
-        CallKind::Normal { self_arg, desugaring, is_option_or_result }
+        CallKind::Normal { self_arg, desugaring, method_did }
     })
 }

compiler/rustc_errors/src/emitter.rs

@@ -1408,49 +1408,58 @@ impl EmitterWriter {
             if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
                 if !self.short_message {
                     // We'll just print an unannotated message.
-                    for (annotation_id, line) in annotated_file.lines.into_iter().enumerate() {
+                    for (annotation_id, line) in annotated_file.lines.iter().enumerate() {
                         let mut annotations = line.annotations.clone();
                         annotations.sort_by_key(|a| Reverse(a.start_col));
                         let mut line_idx = buffer.num_lines();
-                        buffer.append(
-                            line_idx,
-                            &format!(
-                                "{}:{}:{}",
-                                sm.filename_for_diagnostics(&annotated_file.file.name),
-                                sm.doctest_offset_line(&annotated_file.file.name, line.line_index),
-                                annotations[0].start_col + 1,
-                            ),
-                            Style::LineAndColumn,
-                        );
-                        if annotation_id == 0 {
-                            buffer.prepend(line_idx, "--> ", Style::LineNumber);
+
+                        let labels: Vec<_> = annotations
+                            .iter()
+                            .filter_map(|a| Some((a.label.as_ref()?, a.is_primary)))
+                            .filter(|(l, _)| !l.is_empty())
+                            .collect();
+
+                        if annotation_id == 0 || !labels.is_empty() {
+                            buffer.append(
+                                line_idx,
+                                &format!(
+                                    "{}:{}:{}",
+                                    sm.filename_for_diagnostics(&annotated_file.file.name),
+                                    sm.doctest_offset_line(
+                                        &annotated_file.file.name,
+                                        line.line_index
+                                    ),
+                                    annotations[0].start_col + 1,
+                                ),
+                                Style::LineAndColumn,
+                            );
+                            if annotation_id == 0 {
+                                buffer.prepend(line_idx, "--> ", Style::LineNumber);
+                            } else {
+                                buffer.prepend(line_idx, "::: ", Style::LineNumber);
+                            }
                             for _ in 0..max_line_num_len {
                                 buffer.prepend(line_idx, " ", Style::NoStyle);
                             }
                             line_idx += 1;
-                        };
-                        for (i, annotation) in annotations.into_iter().enumerate() {
-                            if let Some(label) = &annotation.label {
-                                let style = if annotation.is_primary {
-                                    Style::LabelPrimary
-                                } else {
-                                    Style::LabelSecondary
-                                };
-                                if annotation_id == 0 {
-                                    buffer.prepend(line_idx, " |", Style::LineNumber);
-                                    for _ in 0..max_line_num_len {
-                                        buffer.prepend(line_idx, " ", Style::NoStyle);
-                                    }
-                                    line_idx += 1;
-                                    buffer.append(line_idx + i, " = note: ", style);
-                                    for _ in 0..max_line_num_len {
-                                        buffer.prepend(line_idx, " ", Style::NoStyle);
-                                    }
-                                } else {
-                                    buffer.append(line_idx + i, ": ", style);
-                                }
-                                buffer.append(line_idx + i, label, style);
+                        }
+                        for (label, is_primary) in labels.into_iter() {
+                            let style = if is_primary {
+                                Style::LabelPrimary
+                            } else {
+                                Style::LabelSecondary
+                            };
+                            buffer.prepend(line_idx, " |", Style::LineNumber);
+                            for _ in 0..max_line_num_len {
+                                buffer.prepend(line_idx, " ", Style::NoStyle);
+                            }
+                            line_idx += 1;
+                            buffer.append(line_idx, " = note: ", style);
+                            for _ in 0..max_line_num_len {
+                                buffer.prepend(line_idx, " ", Style::NoStyle);
                             }
+                            buffer.append(line_idx, label, style);
+                            line_idx += 1;
                         }
                     }
                 }

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -1853,7 +1853,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         )],
     ) {
         let mut derives = Vec::<(String, Span, Symbol)>::new();
-        let mut traits = Vec::<Span>::new();
+        let mut traits = Vec::new();
         for (pred, _, _) in unsatisfied_predicates {
             let ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred)) = pred.kind().skip_binder() else { continue };
             let adt = match trait_pred.self_ty().ty_adt_def() {
@@ -1892,10 +1892,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                     derives.push((self_name, self_span, diagnostic_name));
                 } else {
-                    traits.push(self.tcx.def_span(trait_pred.def_id()));
+                    traits.push(trait_pred.def_id());
                 }
             } else {
-                traits.push(self.tcx.def_span(trait_pred.def_id()));
+                traits.push(trait_pred.def_id());
             }
         }
         traits.sort();
@@ -1918,10 +1918,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let len = traits.len();
         if len > 0 {
-            let span: MultiSpan = traits.into();
+            let span =
+                MultiSpan::from_spans(traits.iter().map(|&did| self.tcx.def_span(did)).collect());
+            let mut names = format!("`{}`", self.tcx.def_path_str(traits[0]));
+            for (i, &did) in traits.iter().enumerate().skip(1) {
+                if len > 2 {
+                    names.push_str(", ");
+                }
+                if i == len - 1 {
+                    names.push_str(" and ");
+                }
+                names.push('`');
+                names.push_str(&self.tcx.def_path_str(did));
+                names.push('`');
+            }
             err.span_note(
                 span,
-                &format!("the following trait{} must be implemented", pluralize!(len),),
+                &format!("the trait{} {} must be implemented", pluralize!(len), names),
             );
         }
 

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -1527,13 +1527,15 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                 if let Some(virtual_dir) = &sess.opts.unstable_opts.simulate_remapped_rust_src_base
                 {
                     if let Some(real_dir) = &sess.opts.real_rust_source_base_dir {
-                        if let rustc_span::FileName::Real(ref mut old_name) = name {
-                            if let rustc_span::RealFileName::LocalPath(local) = old_name {
-                                if let Ok(rest) = local.strip_prefix(real_dir) {
-                                    *old_name = rustc_span::RealFileName::Remapped {
-                                        local_path: None,
-                                        virtual_name: virtual_dir.join(rest),
-                                    };
+                        for subdir in ["library", "compiler"] {
+                            if let rustc_span::FileName::Real(ref mut old_name) = name {
+                                if let rustc_span::RealFileName::LocalPath(local) = old_name {
+                                    if let Ok(rest) = local.strip_prefix(real_dir.join(subdir)) {
+                                        *old_name = rustc_span::RealFileName::Remapped {
+                                            local_path: None,
+                                            virtual_name: virtual_dir.join(subdir).join(rest),
+                                        };
+                                    }
                                 }
                             }
                         }

compiler/rustc_privacy/src/lib.rs

@@ -1308,15 +1308,15 @@ impl<'tcx> Visitor<'tcx> for TypePrivacyVisitor<'tcx> {
             let is_local_static =
                 if let DefKind::Static(_) = kind { def_id.is_local() } else { false };
             if !self.item_is_accessible(def_id) && !is_local_static {
-                let sess = self.tcx.sess;
-                let sm = sess.source_map();
-                let name = match qpath {
-                    hir::QPath::Resolved(..) | hir::QPath::LangItem(..) => {
-                        sm.span_to_snippet(qpath.span()).ok()
+                let name = match *qpath {
+                    hir::QPath::LangItem(it, ..) => {
+                        self.tcx.lang_items().get(it).map(|did| self.tcx.def_path_str(did))
                     }
+                    hir::QPath::Resolved(_, path) => Some(self.tcx.def_path_str(path.res.def_id())),
                     hir::QPath::TypeRelative(_, segment) => Some(segment.ident.to_string()),
                 };
                 let kind = kind.descr(def_id);
+                let sess = self.tcx.sess;
                 let _ = match name {
                     Some(name) => {
                         sess.emit_err(ItemIsPrivate { span, kind, descr: (&name).into() })

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

@@ -2179,15 +2179,15 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             format!("does not implement `{}`", trait_pred.print_modifiers_and_trait_path())
         };
 
-        let mut explain_yield = |interior_span: Span,
-                                 yield_span: Span,
-                                 scope_span: Option<Span>| {
-            let mut span = MultiSpan::from_span(yield_span);
-            if let Ok(snippet) = source_map.span_to_snippet(interior_span) {
-                // #70935: If snippet contains newlines, display "the value" instead
-                // so that we do not emit complex diagnostics.
-                let snippet = &format!("`{}`", snippet);
-                let snippet = if snippet.contains('\n') { "the value" } else { snippet };
+        let mut explain_yield =
+            |interior_span: Span, yield_span: Span, scope_span: Option<Span>| {
+                let mut span = MultiSpan::from_span(yield_span);
+                let snippet = match source_map.span_to_snippet(interior_span) {
+                    // #70935: If snippet contains newlines, display "the value" instead
+                    // so that we do not emit complex diagnostics.
+                    Ok(snippet) if !snippet.contains('\n') => format!("`{}`", snippet),
+                    _ => "the value".to_string(),
+                };
                 // note: future is not `Send` as this value is used across an await
                 //   --> $DIR/issue-70935-complex-spans.rs:13:9
                 //    |
@@ -2212,17 +2212,11 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     interior_span,
                     format!("has type `{}` which {}", target_ty, trait_explanation),
                 );
-                // If available, use the scope span to annotate the drop location.
-                let mut scope_note = None;
                 if let Some(scope_span) = scope_span {
                     let scope_span = source_map.end_point(scope_span);
 
                     let msg = format!("{} is later dropped here", snippet);
-                    if source_map.is_multiline(yield_span.between(scope_span)) {
-                        span.push_span_label(scope_span, msg);
-                    } else {
-                        scope_note = Some((scope_span, msg));
-                    }
+                    span.push_span_label(scope_span, msg);
                 }
                 err.span_note(
                     span,
@@ -2231,11 +2225,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                         future_or_generator, trait_explanation, an_await_or_yield
                     ),
                 );
-                if let Some((span, msg)) = scope_note {
-                    err.span_note(span, &msg);
-                }
-            }
-        };
+            };
         match interior_or_upvar_span {
             GeneratorInteriorOrUpvar::Interior(interior_span, interior_extra_info) => {
                 if let Some((scope_span, yield_span, expr, from_awaited_ty)) = interior_extra_info {

src/test/ui-fulldeps/session-diagnostic/diagnostic-derive.stderr

@@ -660,10 +660,7 @@ LL | #[derive(Diagnostic)]
    = help: normalized in stderr
 note: required by a bound in `DiagnosticBuilder::<'a, G>::set_arg`
   --> $COMPILER_DIR/rustc_errors/src/diagnostic_builder.rs:LL:CC
-   |
-LL |         arg: impl IntoDiagnosticArg,
-   |                   ^^^^^^^^^^^^^^^^^ required by this bound in `DiagnosticBuilder::<'a, G>::set_arg`
-   = note: this error originates in the derive macro `Diagnostic` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `Diagnostic` which comes from the expansion of the macro `forward` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 83 previous errors
 

src/test/ui/alloc-error/alloc-error-handler-bad-signature-2.stderr

@@ -17,9 +17,6 @@ LL | |  }
    = note: struct `core::alloc::Layout` and struct `Layout` have similar names, but are actually distinct types
 note: struct `core::alloc::Layout` is defined in crate `core`
   --> $SRC_DIR/core/src/alloc/layout.rs:LL:COL
-   |
-LL | pub struct Layout {
-   | ^^^^^^^^^^^^^^^^^
 note: struct `Layout` is defined in the current crate
   --> $DIR/alloc-error-handler-bad-signature-2.rs:7:1
    |

src/test/ui/associated-type-bounds/issue-99828.stderr

@@ -15,9 +15,6 @@ LL | fn get_iter(vec: &[i32]) -> impl Iterator<Item = {}> + '_ {
    |
 note: associated type defined here
   --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
-   |
-LL |     type Item;
-   |     ^^^^^^^^^
 
 error: aborting due to 2 previous errors
 

src/test/ui/associated-types/defaults-wf.stderr

@@ -7,9 +7,6 @@ LL |     type Ty = Vec<[u8]>;
    = help: the trait `Sized` is not implemented for `[u8]`
 note: required by a bound in `Vec`
   --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
-   |
-LL | pub struct Vec<T, #[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global> {
-   |                ^ required by this bound in `Vec`
 
 error: aborting due to previous error
 

src/test/ui/associated-types/trait-with-supertraits-needing-sized-self.stderr

@@ -6,9 +6,6 @@ LL | trait ArithmeticOps: Add<Output=Self> + Sub<Output=Self> + Mul<Output=Self>
    |
 note: required by a bound in `Add`
   --> $SRC_DIR/core/src/ops/arith.rs:LL:COL
-   |
-LL | pub trait Add<Rhs = Self> {
-   |               ^^^^^^^^^^ required by this bound in `Add`
 help: consider further restricting `Self`
    |
 LL | trait ArithmeticOps: Add<Output=Self> + Sub<Output=Self> + Mul<Output=Self> + Div<Output=Self> + Sized {}