Unify wording of "failed to resolve" errors with "cannot find" resolution errors

* Use the same wording for all macro resolution errors
* specify the scope in which the resolution failure happened

Before

```
error[E0433]: failed to resolve: `crate` in paths can only be used in start position
  --> $DIR/crate-path-non-absolute.rs:5:22
   |
LL |         let s = ::m::crate::S;
   |                      ^^^^^ `crate` in paths can only be used in start position
```
after
```
error[E0433]: cannot find module `crate` in module `m`
  --> $DIR/crate-path-non-absolute.rs:5:22
   |
LL |         let s = ::m::crate::S;
   |                      ^^^^^ `crate` in paths can only be used in start position
```

Author: estebank

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -382,9 +382,15 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                     PathResult::NonModule(partial_res) => {
                         expected_found_error(partial_res.expect_full_res())
                     }
-                    PathResult::Failed { span, label, suggestion, .. } => {
-                        Err(VisResolutionError::FailedToResolve(span, label, suggestion))
-                    }
+                    PathResult::Failed {
+                        span, label, suggestion, segment_name, item_type, ..
+                    } => Err(VisResolutionError::FailedToResolve(
+                        span,
+                        segment_name,
+                        label,
+                        suggestion,
+                        item_type,
+                    )),
                     PathResult::Indeterminate => Err(VisResolutionError::Indeterminate(path.span)),
                 }
             }

compiler/rustc_resolve/src/diagnostics.rs

@@ -792,9 +792,32 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
                 self.dcx().create_err(errs::SelfImportOnlyInImportListWithNonEmptyPrefix { span })
             }
-            ResolutionError::FailedToResolve { segment, label, suggestion, module } => {
-                let mut err =
-                    struct_span_code_err!(self.dcx(), span, E0433, "failed to resolve: {label}");
+            ResolutionError::FailedToResolve { segment, label, suggestion, module, item_type } => {
+                let mut err = struct_span_code_err!(
+                    self.dcx(),
+                    span,
+                    E0433,
+                    "cannot find {item_type} `{segment}` in {}",
+                    match module {
+                        Some(ModuleOrUniformRoot::CurrentScope) | None => "this scope".to_string(),
+                        Some(ModuleOrUniformRoot::Module(module)) => {
+                            match module.kind {
+                                ModuleKind::Def(_, _, None) => {
+                                    "the crate root".to_string()
+                                }
+                                ModuleKind::Def(kind, def_id, Some(name)) => {
+                                    format!("{} `{name}`", kind.descr(def_id))
+                                }
+                                ModuleKind::Block => "this scope".to_string(),
+                            }
+                        }
+                        Some(ModuleOrUniformRoot::CrateRootAndExternPrelude) => {
+                            "the crate root or the list of imported crates".to_string()
+                        }
+                        Some(ModuleOrUniformRoot::ExternPrelude) =>
+                            "the list of imported crates".to_string(),
+                    },
+                );
                 err.span_label(span, label);
 
                 if let Some((suggestions, msg, applicability)) = suggestion {
@@ -806,7 +829,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 }
                 if let Some(ModuleOrUniformRoot::Module(module)) = module
                     && let Some(module) = module.opt_def_id()
-                    && let Some(segment) = segment
                 {
                     self.find_cfg_stripped(&mut err, &segment, module);
                 }
@@ -1003,10 +1025,18 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             VisResolutionError::AncestorOnly(span) => {
                 self.dcx().create_err(errs::AncestorOnly(span))
             }
-            VisResolutionError::FailedToResolve(span, label, suggestion) => self.into_struct_error(
-                span,
-                ResolutionError::FailedToResolve { segment: None, label, suggestion, module: None },
-            ),
+            VisResolutionError::FailedToResolve(span, segment, label, suggestion, item_type) => {
+                self.into_struct_error(
+                    span,
+                    ResolutionError::FailedToResolve {
+                        segment,
+                        label,
+                        suggestion,
+                        module: None,
+                        item_type,
+                    },
+                )
+            }
             VisResolutionError::ExpectedFound(span, path_str, res) => {
                 self.dcx().create_err(errs::ExpectedModuleFound { span, res, path_str })
             }

compiler/rustc_resolve/src/ident.rs

@@ -1,7 +1,7 @@
 use Determinacy::*;
 use Namespace::*;
 use rustc_ast::{self as ast, NodeId};
-use rustc_errors::ErrorGuaranteed;
+use rustc_errors::{Applicability, ErrorGuaranteed};
 use rustc_hir::def::{DefKind, Namespace, NonMacroAttrKind, PartialRes, PerNS};
 use rustc_middle::{bug, ty};
 use rustc_session::lint::BuiltinLintDiag;
@@ -1483,13 +1483,42 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                             Some(ModuleOrUniformRoot::Module(self.resolve_self(&mut ctxt, parent)));
                         continue;
                     }
+                    let mut item_type = "module";
+                    if path.len() == 1
+                        && let Some(ribs) = ribs
+                        && let RibKind::Normal = ribs[ValueNS][ribs[ValueNS].len() - 1].kind
+                    {
+                        item_type = "item";
+                    }
                     return PathResult::failed(
                         ident,
                         false,
                         finalize.is_some(),
                         module_had_parse_errors,
                         module,
-                        || ("there are too many leading `super` keywords".to_string(), None),
+                        || {
+                            let mut suggestion = None;
+                            let label = if path.len() == 1
+                                && let Some(ribs) = ribs
+                                && let RibKind::Normal = ribs[ValueNS][ribs[ValueNS].len() - 1].kind
+                            {
+                                suggestion = Some((
+                                    vec![(ident.span.shrink_to_lo(), "r#".to_string())],
+                                    "if you still want to call your identifier `super`, use the \
+                                     raw identifier format"
+                                        .to_string(),
+                                    Applicability::MachineApplicable,
+                                ));
+                                "can't use `super` as an identifier"
+                            } else if segment_idx == 0 {
+                                "can't use `super` on the crate root, there are no further modules \
+                                 to go \"up\" to"
+                            } else {
+                                "there are too many leading `super` keywords"
+                            };
+                            (label.to_string(), suggestion)
+                        },
+                        item_type,
                     );
                 }
                 if segment_idx == 0 {
@@ -1547,6 +1576,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         };
                         (label, None)
                     },
+                    "module",
                 );
             }
 
@@ -1651,6 +1681,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                                 );
                                 (label, None)
                             },
+                            "module",
                         );
                     }
                 }
@@ -1685,6 +1716,11 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                                 ident,
                             )
                         },
+                        match opt_ns {
+                            Some(ValueNS) if path.len() == 1 => "item or value",
+                            Some(ns) if path.len() - 1 == segment_idx => ns.descr(),
+                            Some(_) | None => "item",
+                        },
                     );
                 }
             }

compiler/rustc_resolve/src/imports.rs

@@ -920,16 +920,18 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 suggestion,
                 module,
                 error_implied_by_parse_error: _,
+                item_type,
             } => {
                 if no_ambiguity {
                     assert!(import.imported_module.get().is_none());
                     self.report_error(
                         span,
                         ResolutionError::FailedToResolve {
-                            segment: Some(segment_name),
+                            segment: segment_name,
                             label,
                             suggestion,
                             module,
+                            item_type,
                         },
                     );
                 }

compiler/rustc_resolve/src/late.rs

@@ -4696,14 +4696,16 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                 module,
                 segment_name,
                 error_implied_by_parse_error: _,
+                item_type,
             } => {
                 return Err(respan(
                     span,
                     ResolutionError::FailedToResolve {
-                        segment: Some(segment_name),
+                        segment: segment_name,
                         label,
                         suggestion,
                         module,
+                        item_type,
                     },
                 ));
             }

compiler/rustc_resolve/src/lib.rs

@@ -253,10 +253,11 @@ enum ResolutionError<'ra> {
     SelfImportOnlyInImportListWithNonEmptyPrefix,
     /// Error E0433: failed to resolve.
     FailedToResolve {
-        segment: Option<Symbol>,
+        segment: Symbol,
         label: String,
         suggestion: Option<Suggestion>,
         module: Option<ModuleOrUniformRoot<'ra>>,
+        item_type: &'static str,
     },
     /// Error E0434: can't capture dynamic environment in a fn item.
     CannotCaptureDynamicEnvironmentInFnItem,
@@ -315,7 +316,7 @@ enum ResolutionError<'ra> {
 enum VisResolutionError<'a> {
     Relative2018(Span, &'a ast::Path),
     AncestorOnly(Span),
-    FailedToResolve(Span, String, Option<Suggestion>),
+    FailedToResolve(Span, Symbol, String, Option<Suggestion>, &'static str),
     ExpectedFound(Span, String, Res),
     Indeterminate(Span),
     ModuleOnly(Span),
@@ -458,6 +459,7 @@ enum PathResult<'ra> {
         /// The segment name of target
         segment_name: Symbol,
         error_implied_by_parse_error: bool,
+        item_type: &'static str,
     },
 }
 
@@ -469,6 +471,7 @@ impl<'ra> PathResult<'ra> {
         error_implied_by_parse_error: bool,
         module: Option<ModuleOrUniformRoot<'ra>>,
         label_and_suggestion: impl FnOnce() -> (String, Option<Suggestion>),
+        item_type: &'static str,
     ) -> PathResult<'ra> {
         let (label, suggestion) =
             if finalize { label_and_suggestion() } else { (String::new(), None) };
@@ -480,6 +483,7 @@ impl<'ra> PathResult<'ra> {
             is_error_from_last_segment,
             module,
             error_implied_by_parse_error,
+            item_type,
         }
     }
 }

compiler/rustc_resolve/src/macros.rs

@@ -856,8 +856,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 ),
                 path_res @ (PathResult::NonModule(..) | PathResult::Failed { .. }) => {
                     let mut suggestion = None;
-                    let (span, label, module, segment) =
-                        if let PathResult::Failed { span, label, module, segment_name, .. } =
+                    let (span, label, module, segment, item_type) =
+                        if let PathResult::Failed { span, label, module, segment_name, item_type, .. } =
                             path_res
                         {
                             // try to suggest if it's not a macro, maybe a function
@@ -877,26 +877,24 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                                     Applicability::MaybeIncorrect,
                                 ));
                             }
-                            (span, label, module, segment_name)
+                            (span, label, module, segment_name, item_type)
                         } else {
                             (
                                 path_span,
-                                format!(
-                                    "partially resolved path in {} {}",
-                                    kind.article(),
-                                    kind.descr()
-                                ),
+                                "partially resolved path in a macro".to_string(),
                                 None,
                                 path.last().map(|segment| segment.ident.name).unwrap(),
+                                "macro",
                             )
                         };
                     self.report_error(
                         span,
                         ResolutionError::FailedToResolve {
-                            segment: Some(segment),
+                            segment,
                             label,
                             suggestion,
                             module,
+                            item_type,
                         },
                     );
                 }

src/tools/clippy/tests/ui/crashes/unreachable-array-or-slice.stderr

@@ -1,4 +1,4 @@
-error[E0433]: failed to resolve: `Self` is only available in impls, traits, and type definitions
+error[E0433]: cannot find item `Self` in this scope
   --> tests/ui/crashes/unreachable-array-or-slice.rs:4:9
    |
 LL |     let Self::anything_here_kills_it(a, b, ..) = Foo(5, 5, 5, 5);

tests/rustdoc-ui/intra-doc/unresolved-import-recovery.rs

@@ -1,6 +1,6 @@
 // Regression test for issue #95879.
 
-use unresolved_crate::module::Name; //~ ERROR failed to resolve
+use unresolved_crate::module::Name; //~ ERROR cannot find item
 
 /// [Name]
 pub struct S;

tests/rustdoc-ui/intra-doc/unresolved-import-recovery.stderr

@@ -1,4 +1,4 @@
-error[E0433]: failed to resolve: use of unresolved module or unlinked crate `unresolved_crate`
+error[E0433]: cannot find item `unresolved_crate` in the crate root
   --> $DIR/unresolved-import-recovery.rs:3:5
    |
 LL | use unresolved_crate::module::Name;