Auto merge of #35476 - jonathandturner:rollup, r=jonathandturner

Rollup of 6 pull requests

- Successful merges: #35396, #35402, #35446, #35466, #35470, #35475
- Failed merges: #35395, #35415

Author: bors

src/doc/book/crates-and-modules.md

@@ -22,6 +22,7 @@ As an example, let’s make a *phrases* crate, which will give us various phrase
 in different languages. To keep things simple, we’ll stick to ‘greetings’ and
 ‘farewells’ as two kinds of phrases, and use English and Japanese (日本語) as
 two languages for those phrases to be in. We’ll use this module layout:
+
 ```text
                                     +-----------+
                                 +---| greetings |

src/librustc_typeck/astconv.rs

@@ -360,8 +360,11 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                 self.convert_angle_bracketed_parameters(rscope, span, decl_generics, data)
             }
             hir::ParenthesizedParameters(..) => {
-                span_err!(tcx.sess, span, E0214,
-                          "parenthesized parameters may only be used with a trait");
+                struct_span_err!(tcx.sess, span, E0214,
+                          "parenthesized parameters may only be used with a trait")
+                    .span_label(span, &format!("only traits may use parentheses"))
+                    .emit();
+
                 let ty_param_defs = decl_generics.types.get_slice(TypeSpace);
                 (Substs::empty(),
                  ty_param_defs.iter().map(|_| tcx.types.err).collect(),
@@ -1201,10 +1204,13 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
         }
 
         for (trait_def_id, name) in associated_types {
-            span_err!(tcx.sess, span, E0191,
+            struct_span_err!(tcx.sess, span, E0191,
                 "the value of the associated type `{}` (from the trait `{}`) must be specified",
                         name,
-                        tcx.item_path_str(trait_def_id));
+                        tcx.item_path_str(trait_def_id))
+                        .span_label(span, &format!(
+                            "missing associated type `{}` value", name))
+                        .emit();
         }
 
         tcx.mk_trait(object.principal, object.bounds)
@@ -1584,9 +1590,11 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                 return self.tcx().types.err;
             }
             _ => {
-                span_err!(tcx.sess, span, E0248,
-                          "found value `{}` used as a type",
-                          tcx.item_path_str(def.def_id()));
+                struct_span_err!(tcx.sess, span, E0248,
+                           "found value `{}` used as a type",
+                            tcx.item_path_str(def.def_id()))
+                           .span_label(span, &format!("value used as a type"))
+                           .emit();
                 return self.tcx().types.err;
             }
         }

src/librustc_typeck/check/_match.rs

@@ -633,10 +633,23 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 self.check_pat(&subpat, field_ty);
             }
         } else {
-            span_err!(tcx.sess, pat.span, E0023,
-                      "this pattern has {} field{s}, but the corresponding {} has {} field{s}",
-                      subpats.len(), def.kind_name(), variant.fields.len(),
-                      s = if variant.fields.len() == 1 {""} else {"s"});
+            let subpats_ending = if subpats.len() == 1 {
+                ""
+            } else {
+                "s"
+            };
+            let fields_ending = if variant.fields.len() == 1 {
+                ""
+            } else {
+                "s"
+            };
+            struct_span_err!(tcx.sess, pat.span, E0023,
+                             "this pattern has {} field{}, but the corresponding {} has {} field{}",
+                             subpats.len(), subpats_ending, def.kind_name(),
+                             variant.fields.len(),  fields_ending)
+                .span_label(pat.span, &format!("expected {} field{}, found {}",
+                                               variant.fields.len(), fields_ending, subpats.len()))
+                .emit();
             on_error();
         }
     }

src/librustc_typeck/coherence/mod.rs

@@ -330,10 +330,17 @@ impl<'a, 'gcx, 'tcx> CoherenceChecker<'a, 'gcx, 'tcx> {
                            .emit()
                 }
                 Err(CopyImplementationError::NotAnAdt) => {
-                       span_err!(tcx.sess, span, E0206,
-                                 "the trait `Copy` may not be implemented \
-                                  for this type; type is not a structure or \
-                                  enumeration")
+                    let item = tcx.map.expect_item(impl_node_id);
+                    let span = if let ItemImpl(_, _, _, _, ref ty, _) = item.node {
+                        ty.span
+                    } else {
+                        span
+                    };
+
+                    struct_span_err!(tcx.sess, span, E0206,
+                                     "the trait `Copy` may not be implemented for this type")
+                        .span_label(span, &format!("type is not a structure or enumeration"))
+                        .emit();
                 }
                 Err(CopyImplementationError::HasDestructor) => {
                     span_err!(tcx.sess, span, E0184,

src/test/compile-fail/E0023.rs

@@ -13,10 +13,15 @@ enum Fruit {
     Pear(u32),
 }
 
+
 fn main() {
     let x = Fruit::Apple(String::new(), String::new());
     match x {
         Fruit::Apple(a) => {}, //~ ERROR E0023
+                               //~| NOTE expected 2 fields, found 1
         Fruit::Apple(a, b, c) => {}, //~ ERROR E0023
+                                     //~| NOTE expected 2 fields, found 3
+        Fruit::Pear(1, 2) => {}, //~ ERROR E0023
+                                 //~| NOTE expected 1 field, found 2
     }
 }

src/test/compile-fail/E0191.rs

@@ -13,6 +13,7 @@ trait Trait {
 }
 
 type Foo = Trait; //~ ERROR E0191
+                  //~| NOTE missing associated type `Bar` value
 
 fn main() {
 }

src/test/compile-fail/E0206.rs

@@ -10,13 +10,17 @@
 
 type Foo = i32;
 
-impl Copy for Foo { } //~ ERROR E0206
-                      //~^ ERROR E0117
+impl Copy for Foo { }
+//~^ ERROR the trait `Copy` may not be implemented for this type
+//~| NOTE type is not a structure or enumeration
+//~| ERROR E0117
 
 #[derive(Copy, Clone)]
 struct Bar;
 
-impl Copy for &'static Bar { } //~ ERROR E0206
+impl Copy for &'static Bar { }
+//~^ ERROR the trait `Copy` may not be implemented for this type
+//~| NOTE type is not a structure or enumeration
 
 fn main() {
 }

src/test/compile-fail/E0214.rs

@@ -9,5 +9,7 @@
 // except according to those terms.
 
 fn main() {
-    let v: Vec(&str) = vec!["foo"]; //~ ERROR E0214
+    let v: Vec(&str) = vec!["foo"];
+    //~^ ERROR E0214
+    //~| NOTE only traits may use parentheses
 }

src/test/compile-fail/E0248.rs

@@ -13,6 +13,6 @@ enum Foo {
 }
 
 fn do_something(x: Foo::Bar) { } //~ ERROR E0248
-
+                //~| NOTE value used as a type
 fn main() {
 }

src/test/compile-fail/associated-type-projection-from-multiple-supertraits.rs

@@ -37,6 +37,7 @@ fn dent_object<COLOR>(c: BoxCar<Color=COLOR>) {
     //~| ERROR the value of the associated type `Color` (from the trait `Vehicle`) must be specified
     //~| NOTE could derive from `Vehicle`
     //~| NOTE could derive from `Box`
+    //~| NOTE missing associated type `Color` value
 }
 
 fn paint<C:BoxCar>(c: C, d: C::Color) {