add a label to struct/enum/union ident name

compiler/rustc_parse/src/parser/item.rs

@@ -1318,7 +1318,8 @@ impl<'a> Parser<'a> {
             (vec![], false)
         } else {
             self.parse_delim_comma_seq(Delimiter::Brace, |p| p.parse_enum_variant()).map_err(
-                |e| {
+                |mut e| {
+                    e.span_label(id.span, "while parsing this enum");
                     self.recover_stmt();
                     e
                 },
@@ -1345,7 +1346,8 @@ impl<'a> Parser<'a> {
 
                 let struct_def = if this.check(&token::OpenDelim(Delimiter::Brace)) {
                     // Parse a struct variant.
-                    let (fields, recovered) = this.parse_record_struct_body("struct", false)?;
+                    let (fields, recovered) =
+                        this.parse_record_struct_body("struct", ident.span, false)?;
                     VariantData::Struct(fields, recovered)
                 } else if this.check(&token::OpenDelim(Delimiter::Parenthesis)) {
                     VariantData::Tuple(this.parse_tuple_struct_body()?, DUMMY_NODE_ID)
@@ -1399,8 +1401,11 @@ impl<'a> Parser<'a> {
                 VariantData::Unit(DUMMY_NODE_ID)
             } else {
                 // If we see: `struct Foo<T> where T: Copy { ... }`
-                let (fields, recovered) =
+                let (fields, recovered) = self.parse_record_struct_body(
-                    self.parse_record_struct_body("struct", generics.where_clause.has_where_token)?;
+                    "struct",
+                    class_name.span,
+                    generics.where_clause.has_where_token,
+                )?;
                 VariantData::Struct(fields, recovered)
             }
         // No `where` so: `struct Foo<T>;`
@@ -1408,8 +1413,11 @@ impl<'a> Parser<'a> {
             VariantData::Unit(DUMMY_NODE_ID)
         // Record-style struct definition
         } else if self.token == token::OpenDelim(Delimiter::Brace) {
-            let (fields, recovered) =
+            let (fields, recovered) = self.parse_record_struct_body(
-                self.parse_record_struct_body("struct", generics.where_clause.has_where_token)?;
+                "struct",
+                class_name.span,
+                generics.where_clause.has_where_token,
+            )?;
             VariantData::Struct(fields, recovered)
         // Tuple-style struct definition with optional where-clause.
         } else if self.token == token::OpenDelim(Delimiter::Parenthesis) {
@@ -1438,12 +1446,18 @@ impl<'a> Parser<'a> {
 
         let vdata = if self.token.is_keyword(kw::Where) {
             generics.where_clause = self.parse_where_clause()?;
-            let (fields, recovered) =
+            let (fields, recovered) = self.parse_record_struct_body(
-                self.parse_record_struct_body("union", generics.where_clause.has_where_token)?;
+                "union",
+                class_name.span,
+                generics.where_clause.has_where_token,
+            )?;
             VariantData::Struct(fields, recovered)
         } else if self.token == token::OpenDelim(Delimiter::Brace) {
-            let (fields, recovered) =
+            let (fields, recovered) = self.parse_record_struct_body(
-                self.parse_record_struct_body("union", generics.where_clause.has_where_token)?;
+                "union",
+                class_name.span,
+                generics.where_clause.has_where_token,
+            )?;
             VariantData::Struct(fields, recovered)
         } else {
             let token_str = super::token_descr(&self.token);
@@ -1459,6 +1473,7 @@ impl<'a> Parser<'a> {
     fn parse_record_struct_body(
         &mut self,
         adt_ty: &str,
+        ident_span: Span,
         parsed_where: bool,
     ) -> PResult<'a, (Vec<FieldDef>, /* recovered */ bool)> {
         let mut fields = Vec::new();
@@ -1473,6 +1488,7 @@ impl<'a> Parser<'a> {
                 match field {
                     Ok(field) => fields.push(field),
                     Err(mut err) => {
+                        err.span_label(ident_span, format!("while parsing this {adt_ty}"));
                         err.emit();
                         break;
                     }

src/test/ui/async-await/await-keyword/2018-edition-error-in-non-macro-position.stderr

@@ -46,7 +46,9 @@ error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error-in-non-macro-position.rs:13:14
    |
 LL | struct Foo { await: () }
-   |              ^^^^^ expected identifier, found keyword
+   |        ---   ^^^^^ expected identifier, found keyword
+   |        |
+   |        while parsing this struct
    |
 help: escape `await` to use it as an identifier
    |

src/test/ui/parser/doc-before-struct-rbrace-1.stderr

@@ -1,6 +1,9 @@
 error[E0585]: found a documentation comment that doesn't document anything
   --> $DIR/doc-before-struct-rbrace-1.rs:3:5
    |
+LL | struct X {
+   |        - while parsing this struct
+LL |     a: u8,
 LL |     /// document
    |     ^^^^^^^^^^^^
    |

src/test/ui/parser/fn-field-parse-error-ice.stderr

@@ -7,6 +7,8 @@ LL |     inner : dyn fn ()
 error: functions are not allowed in struct definitions
   --> $DIR/fn-field-parse-error-ice.rs:4:17
    |
+LL | struct Baz {
+   |        --- while parsing this struct
 LL |     inner : dyn fn ()
    |                 ^^
    |

src/test/ui/parser/issues/issue-48636.stderr

@@ -1,6 +1,8 @@
 error[E0585]: found a documentation comment that doesn't document anything
   --> $DIR/issue-48636.rs:7:5
    |
+LL | struct S {
+   |        - while parsing this struct
 LL |     x: u8
    |          - help: missing comma here: `,`
 LL |     /// The ID of the parent core

src/test/ui/parser/issues/issue-68000-unicode-ident-after-missing-comma.stderr

@@ -7,6 +7,8 @@ LL |     pub bar: Vec<i32>ö
 error: expected `:`, found `}`
   --> $DIR/issue-68000-unicode-ident-after-missing-comma.rs:4:1
    |
+LL | pub struct Foo {
+   |            --- while parsing this struct
 LL |     pub bar: Vec<i32>ö
    |                       - expected `:`
 LL |

src/test/ui/parser/macro/issue-37113.stderr

@@ -1,6 +1,8 @@
 error: expected identifier, found `String`
   --> $DIR/issue-37113.rs:4:16
    |
+LL |         enum SomeEnum {
+   |              -------- while parsing this enum
 LL |             $( $t, )*
    |                ^^ expected identifier
 ...

src/test/ui/parser/mismatched-braces/missing-close-brace-in-struct.stderr

@@ -10,6 +10,9 @@ LL | fn main() {}
 error: expected identifier, found keyword `trait`
   --> $DIR/missing-close-brace-in-struct.rs:4:1
    |
+LL | pub(crate) struct Bar<T> {
+   |                   --- while parsing this struct
+...
 LL | trait T {
    | ^^^^^ expected identifier, found keyword
 

src/test/ui/parser/missing-closing-angle-bracket-struct-field-ty.stderr

@@ -1,6 +1,9 @@
 error: expected one of `>`, a const expression, lifetime, or type, found `}`
   --> $DIR/missing-closing-angle-bracket-struct-field-ty.rs:9:1
    |
+LL | pub struct Foo {
+   |            --- while parsing this struct
+...
 LL |     c: Arc<Mutex<usize>>,
    |                          - expected one of `>`, a const expression, lifetime, or type
 LL | }

src/test/ui/parser/recover-enum2.stderr

@@ -1,6 +1,8 @@
 error: expected type, found `{`
   --> $DIR/recover-enum2.rs:6:18
    |
+LL |         Var3 {
+   |         ---- while parsing this struct
 LL |             abc: {},
    |                  ^ expected type
 

src/test/ui/parser/recover-field-semi.stderr

@@ -1,12 +1,16 @@
 error: struct fields are separated by `,`
   --> $DIR/recover-field-semi.rs:2:13
    |
+LL | struct Foo {
+   |        --- while parsing this struct
 LL |     foo: i32;
    |             ^ help: replace `;` with `,`
 
 error: union fields are separated by `,`
   --> $DIR/recover-field-semi.rs:7:13
    |
+LL | union Bar {
+   |       --- while parsing this union
 LL |     foo: i32;
    |             ^ help: replace `;` with `,`
 
@@ -14,7 +18,9 @@ error: struct fields are separated by `,`
   --> $DIR/recover-field-semi.rs:12:19
    |
 LL |     Qux { foo: i32; }
-   |                   ^ help: replace `;` with `,`
+   |     ---           ^ help: replace `;` with `,`
+   |     |
+   |     while parsing this struct
 
 error: unions cannot have zero fields
   --> $DIR/recover-field-semi.rs:6:1

src/test/ui/parser/recover-struct.stderr

@@ -1,6 +1,8 @@
 error: expected `:`, found `Bad`
   --> $DIR/recover-struct.rs:4:9
    |
+LL |     struct Test {
+   |            ---- while parsing this struct
 LL |         Very
    |             - expected `:`
 LL |         Bad

src/test/ui/parser/recovered-struct-variant.stderr

@@ -2,7 +2,9 @@ error: expected `:`, found `,`
   --> $DIR/recovered-struct-variant.rs:2:10
    |
 LL |     A { a, b: usize }
-   |          ^ expected `:`
+   |     -    ^ expected `:`
+   |     |
+   |     while parsing this struct
 
 error: aborting due to previous error
 

src/test/ui/parser/removed-syntax-enum-newtype.stderr

@@ -2,7 +2,9 @@ error: expected one of `<`, `where`, or `{`, found `=`
   --> $DIR/removed-syntax-enum-newtype.rs:1:8
    |
 LL | enum e = isize;
-   |        ^ expected one of `<`, `where`, or `{`
+   |      - ^ expected one of `<`, `where`, or `{`
+   |      |
+   |      while parsing this enum
 
 error: aborting due to previous error
 

src/test/ui/parser/removed-syntax-field-let.stderr

@@ -1,6 +1,8 @@
 error: expected identifier, found keyword `let`
   --> $DIR/removed-syntax-field-let.rs:2:5
    |
+LL | struct S {
+   |        - while parsing this struct
 LL |     let foo: (),
    |     ^^^ expected identifier, found keyword
 

src/test/ui/parser/removed-syntax-field-semicolon.stderr

@@ -1,6 +1,8 @@
 error: struct fields are separated by `,`
   --> $DIR/removed-syntax-field-semicolon.rs:2:12
    |
+LL | struct S {
+   |        - while parsing this struct
 LL |     bar: ();
    |            ^ help: replace `;` with `,`
 

src/test/ui/pattern/issue-66270-pat-struct-parser-recovery.stderr

@@ -1,6 +1,8 @@
 error: expected type, found `0`
   --> $DIR/issue-66270-pat-struct-parser-recovery.rs:4:22
    |
+LL | struct Bug {
+   |        --- while parsing this struct
 LL |     incorrect_field: 0,
    |                      ^ expected type
 

src/test/ui/proc-macro/derive-bad.stderr

@@ -2,7 +2,10 @@ error: expected `:`, found `}`
   --> $DIR/derive-bad.rs:6:10
    |
 LL | #[derive(A)]
-   |          ^ expected `:`
+   |          ^
+   |          |
+   |          expected `:`
+   |          while parsing this struct
    |
    = note: this error originates in the derive macro `A` (in Nightly builds, run with -Z macro-backtrace for more info)
 

src/test/ui/pub/pub-restricted-error.stderr

@@ -1,6 +1,8 @@
 error: expected identifier, found `(`
   --> $DIR/pub-restricted-error.rs:4:16
    |
+LL | struct Foo {
+   |        --- while parsing this struct
 LL |     pub(crate) () foo: usize,
    |                ^ expected identifier
 

src/test/ui/structs/struct-fn-in-definition.stderr

@@ -1,6 +1,9 @@
 error: functions are not allowed in struct definitions
   --> $DIR/struct-fn-in-definition.rs:9:5
    |
+LL | struct S {
+   |        - while parsing this struct
+...
 LL |     fn foo() {}
    |     ^^^^^^^^^^^
    |
@@ -10,6 +13,9 @@ LL |     fn foo() {}
 error: functions are not allowed in union definitions
   --> $DIR/struct-fn-in-definition.rs:18:5
    |
+LL | union U {
+   |       - while parsing this union
+...
 LL |     fn foo() {}
    |     ^^^^^^^^^^^
    |
@@ -19,6 +25,9 @@ LL |     fn foo() {}
 error: functions are not allowed in enum definitions
   --> $DIR/struct-fn-in-definition.rs:27:5
    |
+LL | enum E {
+   |      - while parsing this enum
+...
 LL |     fn foo() {}
    |     ^^^^^^^^^^^
    |

src/test/ui/suggestions/struct-field-type-including-single-colon.stderr

@@ -12,6 +12,8 @@ LL |     a: foo::A,
 error: expected `,`, or `}`, found `:`
   --> $DIR/struct-field-type-including-single-colon.rs:9:11
    |
+LL | struct Foo {
+   |        --- while parsing this struct
 LL |     a: foo:A,
    |           ^
 
@@ -29,6 +31,8 @@ LL |     b: foo::bar::B,
 error: expected `,`, or `}`, found `:`
   --> $DIR/struct-field-type-including-single-colon.rs:15:16
    |
+LL | struct Bar {
+   |        --- while parsing this struct
 LL |     b: foo::bar:B,
    |                ^
 

src/test/ui/typeck/issue-69378-ice-on-invalid-type-node-after-recovery.stderr

@@ -2,7 +2,9 @@ error: expected identifier, found `0`
   --> $DIR/issue-69378-ice-on-invalid-type-node-after-recovery.rs:3:14
    |
 LL | struct Foo { 0: u8 }
-   |              ^ expected identifier
+   |        ---   ^ expected identifier
+   |        |
+   |        while parsing this struct
 
 error: aborting due to previous error