improve unknown enum variant errors

[rust.git] / src / librustc_typeck / check / method / suggest.rs

diff --git a/src/librustc_typeck/check/method/suggest.rs b/src/librustc_typeck/check/method/suggest.rs
index 7b530c69a88820aea6503e2dbf18d4b95e621b7a..31b7724d63816e0a4bc1e75e4182a4d5e895c22e 100644 (file)
--- a/src/librustc_typeck/check/method/suggest.rs
+++ b/src/librustc_typeck/check/method/suggest.rs
@@ -14,11 +14,11 @@
 use rustc::hir::print;
 use rustc::infer::type_variable::TypeVariableOrigin;
 use rustc::traits::Obligation;
-use rustc::ty::{self, Adt, Ty, TyCtxt, ToPolyTraitRef, ToPredicate, TypeFoldable};
+use rustc::ty::{self, Ty, TyCtxt, ToPolyTraitRef, ToPredicate, TypeFoldable};
 use rustc::ty::print::with_crate_prefix;
 use syntax_pos::{Span, FileName};
 use syntax::ast;
-use syntax::util::lev_distance::find_best_match_for_name;
+use syntax::util::lev_distance;
 
 use std::cmp::Ordering;
 
@@ -188,17 +188,10 @@ pub fn report_method_error<'b>(
                 let actual = self.resolve_type_vars_if_possible(&rcvr_ty);
                 let ty_str = self.ty_to_string(actual);
                 let is_method = mode == Mode::MethodCall;
-                let mut suggestion = None;
                 let item_kind = if is_method {
                     "method"
                 } else if actual.is_enum() {
-                    if let Adt(ref adt_def, _) = actual.sty {
-                        let names = adt_def.variants.iter().map(|s| &s.ident.name);
-                        suggestion = find_best_match_for_name(names,
-                                                              &item_name.as_str(),
-                                                              None);
-                    }
-                    "variant"
+                    "variant or associated item"
                 } else {
                     match (item_name.as_str().chars().next(), actual.is_fresh_ty()) {
                         (Some(name), false) if name.is_lowercase() => {
@@ -299,7 +292,7 @@ pub fn report_method_error<'b>(
                         return;
                     } else {
                         span = item_name.span;
-                        let mut err = struct_span_err!(
+                        struct_span_err!(
                             tcx.sess,
                             span,
                             E0599,
@@ -307,17 +300,7 @@ pub fn report_method_error<'b>(
                             item_kind,
                             item_name,
                             ty_str
-                        );
-                        if let Some(suggestion) = suggestion {
-                            // enum variant
-                            err.span_suggestion(
-                                span,
-                                "did you mean",
-                                suggestion.to_string(),
-                                Applicability::MaybeIncorrect,
-                            );
-                        }
-                        err
+                        )
                     }
                 } else {
                     tcx.sess.diagnostic().struct_dummy()
@@ -469,14 +452,36 @@ macro_rules! report_function {
                                                   out_of_scope_traits);
                 }
 
+                if actual.is_enum() {
+                    let adt_def = actual.ty_adt_def().expect("enum is not an ADT");
+                    if let Some(suggestion) = lev_distance::find_best_match_for_name(
+                        adt_def.variants.iter().map(|s| &s.ident.name),
+                        &item_name.as_str(),
+                        None,
+                    ) {
+                        err.span_suggestion(
+                            span,
+                            "there is a variant with a similar name",
+                            suggestion.to_string(),
+                            Applicability::MaybeIncorrect,
+                        );
+                    }
+                }
+
                 if let Some(lev_candidate) = lev_candidate {
+                    let def = lev_candidate.def();
                     err.span_suggestion(
                         span,
-                        "did you mean",
+                        &format!(
+                            "there is {} {} with a similar name",
+                            def.article(),
+                            def.kind_name(),
+                        ),
                         lev_candidate.ident.to_string(),
                         Applicability::MaybeIncorrect,
                     );
                 }
+
                 err.emit();
             }
 
@@ -757,9 +762,13 @@ struct Visitor<'a, 'tcx: 'a> {
 
     impl<'v, 'a, 'tcx> itemlikevisit::ItemLikeVisitor<'v> for Visitor<'a, 'tcx> {
         fn visit_item(&mut self, i: &'v hir::Item) {
-            if let hir::ItemKind::Trait(..) = i.node {
-                let def_id = self.map.local_def_id_from_hir_id(i.hir_id);
-                self.traits.push(def_id);
+            match i.node {
+                hir::ItemKind::Trait(..) |
+                hir::ItemKind::TraitAlias(..) => {
+                    let def_id = self.map.local_def_id_from_hir_id(i.hir_id);
+                    self.traits.push(def_id);
+                }
+                _ => ()
             }
         }
 
@@ -781,7 +790,8 @@ fn handle_external_def(tcx: TyCtxt<'_, '_, '_>,
                            external_mods: &mut FxHashSet<DefId>,
                            def: Def) {
         match def {
-            Def::Trait(def_id) => {
+            Def::Trait(def_id) |
+            Def::TraitAlias(def_id) => {
                 traits.push(def_id);
             }
             Def::Mod(def_id) => {
@@ -853,7 +863,7 @@ fn visit_mod(
         }
         // Find a `use` statement.
         for item_id in &module.item_ids {
-            let item = self.tcx.hir().expect_item(item_id.id);
+            let item = self.tcx.hir().expect_item_by_hir_id(item_id.id);
             match item.node {
                 hir::ItemKind::Use(..) => {
                     // Don't suggest placing a `use` before the prelude