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

Author: oli-obk

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
                 //    |
@@ -2234,8 +2234,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 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

@@ -661,8 +661,7 @@ LL | #[derive(Diagnostic)]
 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: 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)
 
 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 {}

src/test/ui/async-await/generator-desc.stderr

@@ -12,9 +12,6 @@ LL |     fun(async {}, async {});
               found `async` block `[async block@$DIR/generator-desc.rs:10:19: 10:27]`
 note: function defined here
   --> $SRC_DIR/core/src/future/mod.rs:LL:COL
-   |
-LL | pub const fn identity_future<O, Fut: Future<Output = O>>(f: Fut) -> Fut {
-   |              ^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/generator-desc.rs:12:16

src/test/ui/async-await/issue-72442.stderr

@@ -8,9 +8,6 @@ LL |             let mut f = File::open(path.to_str())?;
    |
 note: required by a bound in `File::open`
   --> $SRC_DIR/std/src/fs.rs:LL:COL
-   |
-LL |     pub fn open<P: AsRef<Path>>(path: P) -> io::Result<File> {
-   |                    ^^^^^^^^^^^ required by this bound in `File::open`
 
 error: aborting due to previous error