Rollup merge of rust-lang#59821 - euclio:unknown-enum-variants, r=dav…

…idtwco

improve unknown enum variant errors

Fixes rust-lang#56517.

src/librustc_typeck/astconv.rs

@@ -1362,27 +1362,32 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
                     let msg = format!("expected type, found variant `{}`", assoc_ident);
                     tcx.sess.span_err(span, &msg);
                 } else if qself_ty.is_enum() {
-                    // Report as incorrect enum variant rather than ambiguous type.
                     let mut err = tcx.sess.struct_span_err(
-                        span,
-                        &format!("no variant `{}` on enum `{}`", &assoc_ident.as_str(), qself_ty),
+                        assoc_ident.span,
+                        &format!("no variant `{}` in enum `{}`", assoc_ident, qself_ty),
                     );
-                    // Check if it was a typo.
+
                     let adt_def = qself_ty.ty_adt_def().expect("enum is not an ADT");
                     if let Some(suggested_name) = find_best_match_for_name(
                         adt_def.variants.iter().map(|variant| &variant.ident.name),
                         &assoc_ident.as_str(),
                         None,
                     ) {
                         err.span_suggestion(
-                            span,
-                            "did you mean",
-                            format!("{}::{}", qself_ty, suggested_name),
+                            assoc_ident.span,
+                            "there is a variant with a similar name",
+                            suggested_name.to_string(),
                             Applicability::MaybeIncorrect,
                         );
                     } else {
-                        err.span_label(span, "unknown variant");
+                        err.span_label(span, format!("variant not found in `{}`", qself_ty));
                     }
+
+                    if let Some(sp) = tcx.hir().span_if_local(adt_def.did) {
+                        let sp = tcx.sess.source_map().def_span(sp);
+                        err.span_label(sp, format!("variant `{}` not found here", assoc_ident));
+                    }
+
                     err.emit();
                 } else if !qself_ty.references_error() {
                     // Don't print `TyErr` to the user.

src/librustc_typeck/check/method/suggest.rs

@@ -14,11 +14,11 @@ use rustc::hir::map as hir_map;
 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 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 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() => {
@@ -299,25 +292,15 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                         return;
                     } else {
                         span = item_name.span;
-                        let mut err = struct_span_err!(
+                        struct_span_err!(
                             tcx.sess,
                             span,
                             E0599,
                             "no {} named `{}` found for type `{}` in the current scope",
                             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 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                                                   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();
             }
 

src/test/ui/associated-item/associated-item-enum.rs

@@ -0,0 +1,20 @@
+enum Enum { Variant }
+
+impl Enum {
+    const MISSPELLABLE: i32 = 0;
+    fn misspellable() {}
+}
+
+trait Trait {
+    fn misspellable_trait() {}
+}
+
+impl Trait for Enum {
+    fn misspellable_trait() {}
+}
+
+fn main() {
+    Enum::mispellable(); //~ ERROR no variant or associated item
+    Enum::mispellable_trait(); //~ ERROR no variant or associated item
+    Enum::MISPELLABLE; //~ ERROR no variant or associated item
+}

src/test/ui/associated-item/associated-item-enum.stderr

@@ -0,0 +1,36 @@
+error[E0599]: no variant or associated item named `mispellable` found for type `Enum` in the current scope
+  --> $DIR/associated-item-enum.rs:17:11
+   |
+LL | enum Enum { Variant }
+   | --------- variant or associated item `mispellable` not found here
+...
+LL |     Enum::mispellable();
+   |           ^^^^^^^^^^^
+   |           |
+   |           variant or associated item not found in `Enum`
+   |           help: there is a method with a similar name: `misspellable`
+
+error[E0599]: no variant or associated item named `mispellable_trait` found for type `Enum` in the current scope
+  --> $DIR/associated-item-enum.rs:18:11
+   |
+LL | enum Enum { Variant }
+   | --------- variant or associated item `mispellable_trait` not found here
+...
+LL |     Enum::mispellable_trait();
+   |           ^^^^^^^^^^^^^^^^^ variant or associated item not found in `Enum`
+
+error[E0599]: no variant or associated item named `MISPELLABLE` found for type `Enum` in the current scope
+  --> $DIR/associated-item-enum.rs:19:11
+   |
+LL | enum Enum { Variant }
+   | --------- variant or associated item `MISPELLABLE` not found here
+...
+LL |     Enum::MISPELLABLE;
+   |           ^^^^^^^^^^^
+   |           |
+   |           variant or associated item not found in `Enum`
+   |           help: there is an associated constant with a similar name: `MISSPELLABLE`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0599`.

src/test/ui/auto-ref-slice-plus-ref.stderr

@@ -2,7 +2,7 @@ error[E0599]: no method named `test_mut` found for type `std::vec::Vec<{integer}
   --> $DIR/auto-ref-slice-plus-ref.rs:7:7
    |
 LL |     a.test_mut();
-   |       ^^^^^^^^ help: did you mean: `get_mut`
+   |       ^^^^^^^^ help: there is a method with a similar name: `get_mut`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `test_mut`, perhaps you need to implement it:

src/test/ui/block-result/issue-3563.stderr

@@ -2,7 +2,7 @@ error[E0599]: no method named `b` found for type `&Self` in the current scope
   --> $DIR/issue-3563.rs:3:17
    |
 LL |         || self.b()
-   |                 ^ help: did you mean: `a`
+   |                 ^ help: there is a method with a similar name: `a`
 
 error: aborting due to previous error
 

src/test/ui/bogus-tag.stderr

@@ -1,11 +1,11 @@
-error[E0599]: no variant named `Hsl` found for type `Color` in the current scope
+error[E0599]: no variant or associated item named `Hsl` found for type `Color` in the current scope
   --> $DIR/bogus-tag.rs:7:16
    |
 LL | enum Color { Rgb(isize, isize, isize), Rgba(isize, isize, isize, isize), }
-   | ---------- variant `Hsl` not found here
+   | ---------- variant or associated item `Hsl` not found here
 ...
 LL |         Color::Hsl(h, s, l) => { println!("hsl"); }
-   |                ^^^ variant not found in `Color`
+   |                ^^^ variant or associated item not found in `Color`
 
 error: aborting due to previous error
 

src/test/ui/empty/empty-struct-braces-expr.rs

@@ -19,6 +19,8 @@ fn main() {
 
     let xe1 = XEmpty1; //~ ERROR expected value, found struct `XEmpty1`
     let xe1 = XEmpty1(); //~ ERROR expected function, found struct `XEmpty1`
-    let xe3 = XE::Empty3; //~ ERROR no variant named `Empty3` found for type
-    let xe3 = XE::Empty3(); //~ ERROR no variant named `Empty3` found for type
+    let xe3 = XE::Empty3; //~ ERROR no variant or associated item named `Empty3` found for type
+    let xe3 = XE::Empty3(); //~ ERROR no variant or associated item named `Empty3` found for type
+
+    XE::Empty1 {}; //~ ERROR no variant `Empty1` in enum `empty_struct::XE`
 }

src/test/ui/empty/empty-struct-braces-expr.stderr

@@ -46,25 +46,31 @@ LL |     let xe1 = XEmpty1();
    |               did you mean `XEmpty1 { /* fields */ }`?
    |               help: a unit struct with a similar name exists: `XEmpty2`
 
-error[E0599]: no variant named `Empty3` found for type `empty_struct::XE` in the current scope
+error[E0599]: no variant or associated item named `Empty3` found for type `empty_struct::XE` in the current scope
   --> $DIR/empty-struct-braces-expr.rs:22:19
    |
 LL |     let xe3 = XE::Empty3;
    |                   ^^^^^^
    |                   |
-   |                   variant not found in `empty_struct::XE`
-   |                   help: did you mean: `XEmpty3`
+   |                   variant or associated item not found in `empty_struct::XE`
+   |                   help: there is a variant with a similar name: `XEmpty3`
 
-error[E0599]: no variant named `Empty3` found for type `empty_struct::XE` in the current scope
+error[E0599]: no variant or associated item named `Empty3` found for type `empty_struct::XE` in the current scope
   --> $DIR/empty-struct-braces-expr.rs:23:19
    |
 LL |     let xe3 = XE::Empty3();
    |                   ^^^^^^
    |                   |
-   |                   variant not found in `empty_struct::XE`
-   |                   help: did you mean: `XEmpty3`
+   |                   variant or associated item not found in `empty_struct::XE`
+   |                   help: there is a variant with a similar name: `XEmpty3`
 
-error: aborting due to 8 previous errors
+error: no variant `Empty1` in enum `empty_struct::XE`
+  --> $DIR/empty-struct-braces-expr.rs:25:9
+   |
+LL |     XE::Empty1 {};
+   |         ^^^^^^ help: there is a variant with a similar name: `XEmpty3`
+
+error: aborting due to 9 previous errors
 
 Some errors occurred: E0423, E0599.
 For more information about an error, try `rustc --explain E0423`.

src/test/ui/issues/issue-22933-2.rs

@@ -2,7 +2,7 @@ enum Delicious {
     Pie      = 0x1,
     Apple    = 0x2,
     ApplePie = Delicious::Apple as isize | Delicious::PIE as isize,
-    //~^ ERROR no variant named `PIE` found for type `Delicious`
+    //~^ ERROR no variant or associated item named `PIE` found for type `Delicious`
 }
 
 fn main() {}

src/test/ui/issues/issue-22933-2.stderr

@@ -1,11 +1,11 @@
-error[E0599]: no variant named `PIE` found for type `Delicious` in the current scope
+error[E0599]: no variant or associated item named `PIE` found for type `Delicious` in the current scope
   --> $DIR/issue-22933-2.rs:4:55
    |
 LL | enum Delicious {
-   | -------------- variant `PIE` not found here
+   | -------------- variant or associated item `PIE` not found here
 ...
 LL |     ApplePie = Delicious::Apple as isize | Delicious::PIE as isize,
-   |                                                       ^^^ variant not found in `Delicious`
+   |                                                       ^^^ variant or associated item not found in `Delicious`
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-23173.rs

@@ -6,12 +6,8 @@ struct Struct {
 fn use_token(token: &Token) { unimplemented!() }
 
 fn main() {
-    use_token(&Token::Homura);
-    //~^ ERROR no variant named `Homura`
-    Struct::method();
-    //~^ ERROR no function or associated item named `method` found for type
-    Struct::method;
-    //~^ ERROR no function or associated item named `method` found for type
-    Struct::Assoc;
-    //~^ ERROR no associated item named `Assoc` found for type `Struct` in
+    use_token(&Token::Homura); //~ ERROR no variant or associated item named `Homura`
+    Struct::method(); //~ ERROR no function or associated item named `method` found for type
+    Struct::method; //~ ERROR no function or associated item named `method` found for type
+    Struct::Assoc; //~ ERROR no associated item named `Assoc` found for type `Struct` in
 }

src/test/ui/issues/issue-23173.stderr

@@ -1,14 +1,14 @@
-error[E0599]: no variant named `Homura` found for type `Token` in the current scope
+error[E0599]: no variant or associated item named `Homura` found for type `Token` in the current scope
   --> $DIR/issue-23173.rs:9:23
    |
 LL | enum Token { LeftParen, RightParen, Plus, Minus, /* etc */ }
-   | ---------- variant `Homura` not found here
+   | ---------- variant or associated item `Homura` not found here
 ...
 LL |     use_token(&Token::Homura);
-   |                       ^^^^^^ variant not found in `Token`
+   |                       ^^^^^^ variant or associated item not found in `Token`
 
 error[E0599]: no function or associated item named `method` found for type `Struct` in the current scope
-  --> $DIR/issue-23173.rs:11:13
+  --> $DIR/issue-23173.rs:10:13
    |
 LL | struct Struct {
    | ------------- function or associated item `method` not found for this
@@ -17,7 +17,7 @@ LL |     Struct::method();
    |             ^^^^^^ function or associated item not found in `Struct`
 
 error[E0599]: no function or associated item named `method` found for type `Struct` in the current scope
-  --> $DIR/issue-23173.rs:13:13
+  --> $DIR/issue-23173.rs:11:13
    |
 LL | struct Struct {
    | ------------- function or associated item `method` not found for this
@@ -26,7 +26,7 @@ LL |     Struct::method;
    |             ^^^^^^ function or associated item not found in `Struct`
 
 error[E0599]: no associated item named `Assoc` found for type `Struct` in the current scope
-  --> $DIR/issue-23173.rs:15:13
+  --> $DIR/issue-23173.rs:12:13
    |
 LL | struct Struct {
    | ------------- associated item `Assoc` not found for this

src/test/ui/issues/issue-23217.rs

@@ -1,6 +1,5 @@
 pub enum SomeEnum {
-    B = SomeEnum::A,
-    //~^ ERROR no variant named `A` found for type `SomeEnum`
+    B = SomeEnum::A, //~ ERROR no variant or associated item named `A` found for type `SomeEnum`
 }
 
 fn main() {}

src/test/ui/issues/issue-23217.stderr

@@ -1,13 +1,13 @@
-error[E0599]: no variant named `A` found for type `SomeEnum` in the current scope
+error[E0599]: no variant or associated item named `A` found for type `SomeEnum` in the current scope
   --> $DIR/issue-23217.rs:2:19
    |
 LL | pub enum SomeEnum {
-   | ----------------- variant `A` not found here
+   | ----------------- variant or associated item `A` not found here
 LL |     B = SomeEnum::A,
    |                   ^
    |                   |
-   |                   variant not found in `SomeEnum`
-   |                   help: did you mean: `B`
+   |                   variant or associated item not found in `SomeEnum`
+   |                   help: there is a variant with a similar name: `B`
 
 error: aborting due to previous error