review comments

Author: estebank

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -406,15 +406,15 @@ 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, scope, segment_name, .. } => {
-                        Err(VisResolutionError::FailedToResolve(
-                            span,
-                            segment_name,
-                            label,
-                            suggestion,
-                            scope,
-                        ))
-                    }
+                    PathResult::Failed {
+                        span, label, suggestion, message, segment_name, ..
+                    } => Err(VisResolutionError::FailedToResolve(
+                        span,
+                        segment_name,
+                        label,
+                        suggestion,
+                        message,
+                    )),
                     PathResult::Indeterminate => Err(VisResolutionError::Indeterminate(path.span)),
                 }
             }

compiler/rustc_resolve/src/diagnostics.rs

@@ -788,13 +788,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
                 self.dcx().create_err(errs::SelfImportOnlyInImportListWithNonEmptyPrefix { span })
             }
-            ResolutionError::FailedToResolve { segment, label, suggestion, module, scope } => {
-                let mut err = struct_span_code_err!(
-                    self.dcx(),
-                    span,
-                    E0433,
-                    "cannot find `{segment}` in {scope}"
-                );
+            ResolutionError::FailedToResolve { segment, label, suggestion, module, message } => {
+                let mut err = struct_span_code_err!(self.dcx(), span, E0433, "{message}");
                 err.span_label(span, label);
 
                 if let Some((suggestions, msg, applicability)) = suggestion {
@@ -1003,15 +998,15 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             VisResolutionError::AncestorOnly(span) => {
                 self.dcx().create_err(errs::AncestorOnly(span))
             }
-            VisResolutionError::FailedToResolve(span, segment, label, suggestion, scope) => self
+            VisResolutionError::FailedToResolve(span, segment, label, suggestion, message) => self
                 .into_struct_error(
                     span,
                     ResolutionError::FailedToResolve {
                         segment,
                         label,
                         suggestion,
                         module: None,
-                        scope,
+                        message,
                     },
                 ),
             VisResolutionError::ExpectedFound(span, path_str, res) => {
@@ -2292,13 +2287,25 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         module: Option<ModuleOrUniformRoot<'ra>>,
         failed_segment_idx: usize,
         ident: Ident,
-    ) -> (String, Option<Suggestion>) {
+    ) -> (String, String, Option<Suggestion>) {
         let is_last = failed_segment_idx == path.len() - 1;
         let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
         let module_res = match module {
             Some(ModuleOrUniformRoot::Module(module)) => module.res(),
             _ => None,
         };
+        let scope = match &path[..failed_segment_idx] {
+            [.., prev] => {
+                if prev.ident.name == kw::PathRoot {
+                    format!("the crate root")
+                } else {
+                    format!("`{}`", prev.ident)
+                }
+            }
+            _ => format!("this scope"),
+        };
+        let message = format!("cannot find `{ident}` in {scope}");
+
         if module_res == self.graph_root.res() {
             let is_mod = |res| matches!(res, Res::Def(DefKind::Mod, _));
             let mut candidates = self.lookup_import_candidates(ident, TypeNS, parent_scope, is_mod);
@@ -2316,6 +2323,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     Path { segments, span: Span::default(), tokens: None }
                 };
                 (
+                    message,
                     String::from("unresolved import"),
                     Some((
                         vec![(ident.span, pprust::path_to_string(&path))],
@@ -2325,6 +2333,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 )
             } else if ident.name == sym::core {
                 (
+                    message,
                     format!("you might be missing crate `{ident}`"),
                     Some((
                         vec![(ident.span, "std".to_string())],
@@ -2333,9 +2342,14 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     )),
                 )
             } else if ident.name == kw::Underscore {
-                (format!("`_` is not a valid crate or module name"), None)
+                (
+                    "invalid crate or module name `_`".to_string(),
+                    "`_` is not a valid crate or module name".to_string(),
+                    None,
+                )
             } else if self.tcx.sess.is_rust_2015() {
                 (
+                    format!("cannot find module or crate `{ident}` in {scope}"),
                     format!("use of unresolved module or unlinked crate `{ident}`"),
                     Some((
                         vec![(
@@ -2344,8 +2358,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         )],
                         if was_invoked_from_cargo() {
                             format!(
-                                "if you wanted to use a crate named `{ident}`, use `cargo add {ident}` \
-                             to add it to your `Cargo.toml` and import it in your code",
+                                "if you wanted to use a crate named `{ident}`, use `cargo add \
+                                 {ident}` to add it to your `Cargo.toml` and import it in your \
+                                 code",
                             )
                         } else {
                             format!(
@@ -2357,7 +2372,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     )),
                 )
             } else {
-                (format!("could not find `{ident}` in the crate root"), None)
+                (message, format!("could not find `{ident}` in the crate root"), None)
             }
         } else if failed_segment_idx > 0 {
             let parent = path[failed_segment_idx - 1].ident.name;
@@ -2423,15 +2438,16 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     );
                 };
             }
-            (msg, None)
+            (message, msg, None)
         } else if ident.name == kw::SelfUpper {
             // As mentioned above, `opt_ns` being `None` indicates a module path in import.
             // We can use this to improve a confusing error for, e.g. `use Self::Variant` in an
             // impl
             if opt_ns.is_none() {
-                ("`Self` cannot be used in imports".to_string(), None)
+                (message, "`Self` cannot be used in imports".to_string(), None)
             } else {
                 (
+                    message,
                     "`Self` is only available in impls, traits, and type definitions".to_string(),
                     None,
                 )
@@ -2485,7 +2501,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 )
             });
 
-            (format!("use of undeclared type `{ident}`"), suggestion)
+            (message, format!("use of undeclared type `{ident}`"), suggestion)
         } else {
             let mut suggestion = None;
             if ident.name == sym::alloc {
@@ -2517,7 +2533,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 ignore_import,
             ) {
                 let descr = binding.res().descr();
-                (format!("{descr} `{ident}` is not a crate or module"), suggestion)
+                let message = format!("cannot find module or crate `{ident}` in {scope}");
+                (message, format!("{descr} `{ident}` is not a crate or module"), suggestion)
             } else {
                 let suggestion = if suggestion.is_some() {
                     suggestion
@@ -2539,7 +2556,12 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         Applicability::MaybeIncorrect,
                     ))
                 };
-                (format!("use of unresolved module or unlinked crate `{ident}`"), suggestion)
+                let message = format!("cannot find module or crate `{ident}` in {scope}");
+                (
+                    message,
+                    format!("use of unresolved module or unlinked crate `{ident}`"),
+                    suggestion,
+                )
             }
         }
     }

compiler/rustc_resolve/src/ident.rs

@@ -1513,16 +1513,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
             allow_super &= ns == TypeNS && (name == kw::SelfLower || name == kw::Super);
 
-            let scope = match &path[..segment_idx] {
-                [.., prev] => {
-                    if prev.ident.name == kw::PathRoot {
-                        format!("the crate root")
-                    } else {
-                        format!("`{}`", prev.ident)
-                    }
-                }
-                _ => format!("this scope"),
-            };
             if ns == TypeNS {
                 if allow_super && name == kw::Super {
                     let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
@@ -1546,8 +1536,13 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         finalize.is_some(),
                         module_had_parse_errors,
                         module,
-                        scope,
-                        || ("there are too many leading `super` keywords".to_string(), None),
+                        || {
+                            (
+                                "too many leading `super` keywords".to_string(),
+                                "there are too many leading `super` keywords".to_string(),
+                                None,
+                            )
+                        },
                     );
                 }
                 if segment_idx == 0 {
@@ -1593,7 +1588,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     finalize.is_some(),
                     module_had_parse_errors,
                     module,
-                    scope,
                     || {
                         let name_str = if name == kw::PathRoot {
                             "crate root".to_string()
@@ -1605,7 +1599,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         } else {
                             format!("{name_str} in paths can only be used in start position")
                         };
-                        (label, None)
+                        (label.clone(), label, None)
                     },
                 );
             }
@@ -1717,14 +1711,26 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                             finalize.is_some(),
                             module_had_parse_errors,
                             module,
-                            scope,
                             || {
                                 let label = format!(
                                     "`{ident}` is {} {}, not a module",
                                     res.article(),
                                     res.descr()
                                 );
-                                (label, None)
+                                let scope = match &path[..segment_idx] {
+                                    [.., prev] => {
+                                        if prev.ident.name == kw::PathRoot {
+                                            format!("the crate root")
+                                        } else {
+                                            format!("`{}`", prev.ident)
+                                        }
+                                    }
+                                    _ => format!("this scope"),
+                                };
+                                // FIXME: reword, as the reason we expected a module is because of
+                                // the following path segment.
+                                let message = format!("cannot find module `{ident}` in {scope}");
+                                (message, label, None)
                             },
                         );
                     }
@@ -1748,7 +1754,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                         finalize.is_some(),
                         module_had_parse_errors,
                         module,
-                        scope,
                         || {
                             this.get_mut().report_path_resolution_error(
                                 path,

compiler/rustc_resolve/src/imports.rs

@@ -993,7 +993,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 suggestion,
                 module,
                 error_implied_by_parse_error: _,
-                scope,
+                message,
             } => {
                 if no_ambiguity {
                     assert!(import.imported_module.get().is_none());
@@ -1004,7 +1004,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                             label,
                             suggestion,
                             module,
-                            scope,
+                            message,
                         },
                     );
                 }

compiler/rustc_resolve/src/late.rs

@@ -4599,7 +4599,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                 module,
                 segment_name,
                 error_implied_by_parse_error: _,
-                scope,
+                message,
             } => {
                 return Err(respan(
                     span,
@@ -4608,7 +4608,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                         label,
                         suggestion,
                         module,
-                        scope,
+                        message,
                     },
                 ));
             }

compiler/rustc_resolve/src/lib.rs

@@ -273,7 +273,7 @@ enum ResolutionError<'ra> {
         label: String,
         suggestion: Option<Suggestion>,
         module: Option<ModuleOrUniformRoot<'ra>>,
-        scope: String,
+        message: String,
     },
     /// Error E0434: can't capture dynamic environment in a fn item.
     CannotCaptureDynamicEnvironmentInFnItem,
@@ -477,7 +477,7 @@ enum PathResult<'ra> {
         /// The segment name of target
         segment_name: Symbol,
         error_implied_by_parse_error: bool,
-        scope: String,
+        message: String,
     },
 }
 
@@ -488,11 +488,14 @@ impl<'ra> PathResult<'ra> {
         finalize: bool,
         error_implied_by_parse_error: bool,
         module: Option<ModuleOrUniformRoot<'ra>>,
-        scope: String,
-        label_and_suggestion: impl FnOnce() -> (String, Option<Suggestion>),
+        label_and_suggestion: impl FnOnce() -> (String, String, Option<Suggestion>),
     ) -> PathResult<'ra> {
-        let (label, suggestion) =
-            if finalize { label_and_suggestion() } else { (String::new(), None) };
+        let (message, label, suggestion) = if finalize {
+            label_and_suggestion()
+        } else {
+            // FIXME: this output isn't actually present in the test suite.
+            (format!("cannot find `{ident}` in this scope"), String::new(), None)
+        };
         PathResult::Failed {
             span: ident.span,
             segment_name: ident.name,
@@ -501,7 +504,7 @@ impl<'ra> PathResult<'ra> {
             is_error_from_last_segment,
             module,
             error_implied_by_parse_error,
-            scope,
+            message,
         }
     }
 }