Fixed issues raised in first review.

Alexander Regueiro · Alexander Regueiro · commit a65b5d8bbca9 · 2018-12-11T00:15:20.000Z
diff --git a/src/librustc_typeck/astconv.rs b/src/librustc_typeck/astconv.rs
@@ -41,7 +41,7 @@ use std::collections::BTreeSet;
 use std::iter;
 use std::slice;
 
-use super::{allow_type_alias_enum_variants};
+use super::{check_type_alias_enum_variants_enabled};
 
 pub trait AstConv<'gcx, 'tcx> {
     fn tcx<'a>(&'a self) -> TyCtxt<'a, 'gcx, 'tcx>;
@@ -1263,7 +1263,6 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
                                      ref_id: ast::NodeId,
                                      span: Span,
                                      ty: Ty<'tcx>,
-                                     qself: &hir::Ty,
                                      ty_path_def: Def,
                                      item_segment: &hir::PathSegment)
                                      -> (Ty<'tcx>, Def)
@@ -1282,10 +1281,11 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
                     tcx.hygienic_eq(assoc_name, vd.ident, adt_def.did)
                 });
                 if let Some(variant_def) = variant_def {
-                    if allow_type_alias_enum_variants(tcx, qself, span) {
-                        let def = Def::Variant(variant_def.did);
-                        return (ty, def);
-                    }
+                    check_type_alias_enum_variants_enabled(tcx, span);
+
+                    let def = Def::Variant(variant_def.did);
+                    tcx.check_stability(def.def_id(), Some(ref_id), span);
+                    return (ty, def);
                 }
             }
         }
@@ -1362,8 +1362,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
         let item = tcx.associated_items(trait_did).find(|i| {
             Namespace::from(i.kind) == Namespace::Type &&
                 i.ident.modern() == assoc_ident
-        })
-        .expect("missing associated type");
+        }).expect("missing associated type");
 
         let ty = self.projected_ty_from_poly_trait_ref(span, item.def_id, bound);
         let ty = self.normalize_ty(span, ty);
@@ -1604,7 +1603,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> dyn AstConv<'gcx, 'tcx> + 'o {
                 } else {
                     Def::Err
                 };
-                self.associated_path_def_to_ty(ast_ty.id, ast_ty.span, ty, qself, def, segment).0
+                self.associated_path_def_to_ty(ast_ty.id, ast_ty.span, ty, def, segment).0
             }
             hir::TyKind::Array(ref ty, ref length) => {
                 let length_def_id = tcx.hir().local_def_id(length.id);
diff --git a/src/librustc_typeck/check/method/mod.rs b/src/librustc_typeck/check/method/mod.rs
@@ -35,7 +35,7 @@ use rustc::infer::{self, InferOk};
 use syntax::ast;
 use syntax_pos::Span;
 
-use crate::{allow_type_alias_enum_variants};
+use crate::{check_type_alias_enum_variants_enabled};
 use self::probe::{IsSuggestion, ProbeScope};
 
 pub fn provide(providers: &mut ty::query::Providers) {
@@ -370,7 +370,6 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                         span: Span,
                         method_name: ast::Ident,
                         self_ty: Ty<'tcx>,
-                        qself: &hir::Ty,
                         expr_id: ast::NodeId)
                         -> Result<Def, MethodError<'tcx>> {
         debug!("resolve_ufcs: method_name={:?} self_ty={:?} expr_id={:?}",
@@ -388,10 +387,11 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                     tcx.hygienic_eq(method_name, vd.ident, adt_def.did)
                 });
                 if let Some(variant_def) = variant_def {
-                    if allow_type_alias_enum_variants(tcx, qself, span) {
-                        let def = Def::VariantCtor(variant_def.did, variant_def.ctor_kind);
-                        return Ok(def);
-                    }
+                    check_type_alias_enum_variants_enabled(tcx, span);
+
+                    let def = Def::VariantCtor(variant_def.did, variant_def.ctor_kind);
+                    tcx.check_stability(def.def_id(), Some(expr_id), span);
+                    return Ok(def);
                 }
             }
         }
diff --git a/src/librustc_typeck/check/method/suggest.rs b/src/librustc_typeck/check/method/suggest.rs
@@ -653,7 +653,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
     fn type_derefs_to_local(&self,
                             span: Span,
                             rcvr_ty: Ty<'tcx>,
-                            rcvr_expr: Option<&hir::Expr>) -> bool {
+                            source: SelfSource) -> bool {
         fn is_local(ty: Ty) -> bool {
             match ty.sty {
                 ty::Adt(def, _) => def.did.is_local(),
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
@@ -4458,7 +4458,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                     Def::Err
                 };
                 let (ty, def) = AstConv::associated_path_def_to_ty(self, node_id, path_span,
-                                                                   ty, qself, def, segment);
+                                                                   ty, def, segment);
 
                 // Write back the new resolution.
                 let hir_id = self.tcx.hir().node_to_hir_id(node_id);
@@ -4494,7 +4494,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             return (*cached_def, Some(ty), slice::from_ref(&**item_segment))
         }
         let item_name = item_segment.ident;
-        let def = match self.resolve_ufcs(span, item_name, ty, qself, node_id) {
+        let def = match self.resolve_ufcs(span, item_name, ty, node_id) {
             Ok(def) => def,
             Err(error) => {
                 let def = match error {
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
@@ -114,7 +114,6 @@ mod outlives;
 mod variance;
 
 use hir::Node;
-use hir::def::Def;
 use rustc_target::spec::abi::Abi;
 use rustc::hir;
 use rustc::infer::InferOk;
@@ -140,28 +139,20 @@ pub struct TypeAndSubsts<'tcx> {
     ty: Ty<'tcx>,
 }
 
-fn allow_type_alias_enum_variants<'a, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
-                                                  qself: &hir::Ty,
-                                                  span: Span) -> bool {
-    let allow_feature = tcx.features().type_alias_enum_variants;
-    if !allow_feature {
-        // Only print error if we know the type is an alias.
-        if let hir::TyKind::Path(hir::QPath::Resolved(None, ref path)) = qself.node {
-            if let Def::TyAlias(_) = path.def {
-                let mut err = tcx.sess.struct_span_err(
-                    span,
-                    "enum variants on type aliases are experimental"
-                );
-                if nightly_options::is_nightly_build() {
-                    help!(&mut err,
-                        "add `#![feature(type_alias_enum_variants)]` to the \
-                        crate attributes to enable");
-                }
-                err.emit();
-            }
+fn check_type_alias_enum_variants_enabled<'a, 'gcx, 'tcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>,
+                                                          span: Span) {
+    if !tcx.features().type_alias_enum_variants {
+        let mut err = tcx.sess.struct_span_err(
+            span,
+            "enum variants on type aliases are experimental"
+        );
+        if nightly_options::is_nightly_build() {
+            help!(&mut err,
+                "add `#![feature(type_alias_enum_variants)]` to the \
+                crate attributes to enable");
         }
+        err.emit();
     }
-    allow_feature
 }
 
 fn require_c_abi_if_variadic(tcx: TyCtxt,
diff --git a/src/test/ui/feature-gates/feature-gate-type_alias_enum_variants.rs b/src/test/ui/feature-gates/feature-gate-type_alias_enum_variants.rs
@@ -18,16 +18,12 @@ type Alias = Foo;
 fn main() {
     let t = Alias::Bar(0);
     //~^ ERROR enum variants on type aliases are experimental
-    //~^^ ERROR no variant named `Bar` found for type `Foo` in the current scope
     let t = Alias::Baz { i: 0 };
     //~^ ERROR enum variants on type aliases are experimental
-    //~^^ ERROR ambiguous associated type
     match t {
         Alias::Bar(_i) => {}
         //~^ ERROR enum variants on type aliases are experimental
-        //~^^ ERROR no variant named `Bar` found for type `Foo` in the current scope
         Alias::Baz { i: _i } => {}
         //~^ ERROR enum variants on type aliases are experimental
-        //~^^ ERROR ambiguous associated type
     }
 }
diff --git a/src/test/ui/feature-gates/feature-gate-type_alias_enum_variants.stderr b/src/test/ui/feature-gates/feature-gate-type_alias_enum_variants.stderr
@@ -6,67 +6,29 @@ LL |     let t = Alias::Bar(0);
    |
    = help: add `#![feature(type_alias_enum_variants)]` to the crate attributes to enable
 
-error[E0599]: no variant named `Bar` found for type `Foo` in the current scope
-  --> $DIR/feature-gate-type_alias_enum_variants.rs:19:20
-   |
-LL | enum Foo {
-   | -------- variant `Bar` not found here
-...
-LL |     let t = Alias::Bar(0);
-   |             -------^^^
-   |             |
-   |             variant not found in `Foo`
-   |
-   = help: did you mean `Bar`?
-
 error: enum variants on type aliases are experimental
-  --> $DIR/feature-gate-type_alias_enum_variants.rs:22:13
+  --> $DIR/feature-gate-type_alias_enum_variants.rs:21:13
    |
 LL |     let t = Alias::Baz { i: 0 };
    |             ^^^^^^^^^^
    |
    = help: add `#![feature(type_alias_enum_variants)]` to the crate attributes to enable
 
-error[E0223]: ambiguous associated type
-  --> $DIR/feature-gate-type_alias_enum_variants.rs:22:13
-   |
-LL |     let t = Alias::Baz { i: 0 };
-   |             ^^^^^^^^^^ help: use fully-qualified syntax: `<Foo as Trait>::Baz`
-
 error: enum variants on type aliases are experimental
-  --> $DIR/feature-gate-type_alias_enum_variants.rs:26:9
+  --> $DIR/feature-gate-type_alias_enum_variants.rs:24:9
    |
 LL |         Alias::Bar(_i) => {}
    |         ^^^^^^^^^^^^^^
    |
    = help: add `#![feature(type_alias_enum_variants)]` to the crate attributes to enable
 
-error[E0599]: no variant named `Bar` found for type `Foo` in the current scope
-  --> $DIR/feature-gate-type_alias_enum_variants.rs:26:16
-   |
-LL | enum Foo {
-   | -------- variant `Bar` not found here
-...
-LL |         Alias::Bar(_i) => {}
-   |         -------^^^---- variant not found in `Foo`
-   |
-   = help: did you mean `Bar`?
-
 error: enum variants on type aliases are experimental
-  --> $DIR/feature-gate-type_alias_enum_variants.rs:29:9
+  --> $DIR/feature-gate-type_alias_enum_variants.rs:26:9
    |
 LL |         Alias::Baz { i: _i } => {}
    |         ^^^^^^^^^^
    |
    = help: add `#![feature(type_alias_enum_variants)]` to the crate attributes to enable
 
-error[E0223]: ambiguous associated type
-  --> $DIR/feature-gate-type_alias_enum_variants.rs:29:9
-   |
-LL |         Alias::Baz { i: _i } => {}
-   |         ^^^^^^^^^^ help: use fully-qualified syntax: `<Foo as Trait>::Baz`
-
-error: aborting due to 8 previous errors
+error: aborting due to 4 previous errors
 
-Some errors occurred: E0223, E0599.
-For more information about an error, try `rustc --explain E0223`.
