Rely on regular "expected"/"found" parser error for fn

Author: estebank

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -1550,14 +1550,6 @@ impl<'a> Parser<'a> {
         }
     }
 
-    pub(super) fn expected_semi_or_open_brace<T>(&mut self) -> PResult<'a, T> {
-        let token_str = super::token_descr(&self.token);
-        let msg = &format!("expected `;` or `{{`, found {}", token_str);
-        let mut err = self.struct_span_err(self.token.span, msg);
-        err.span_label(self.token.span, "expected `;` or `{`");
-        Err(err)
-    }
-
     pub(super) fn eat_incorrect_doc_comment_for_param_type(&mut self) {
         if let token::DocComment(..) = self.token.kind {
             self.struct_span_err(

compiler/rustc_parse/src/parser/item.rs

@@ -1551,10 +1551,9 @@ impl<'a> Parser<'a> {
         attrs: &mut Vec<Attribute>,
         sig_hi: &mut Span,
     ) -> PResult<'a, Option<P<Block>>> {
-        let (inner_attrs, body) = if self.check(&token::Semi) {
+        let (inner_attrs, body) = if self.eat(&token::Semi) {
             // Include the trailing semicolon in the span of the signature
-            *sig_hi = self.token.span;
-            self.bump(); // `;`
+            *sig_hi = self.prev_token.span;
             (Vec::new(), None)
         } else if self.check(&token::OpenDelim(token::Brace)) || self.token.is_whole_block() {
             self.parse_inner_attrs_and_block().map(|(attrs, body)| (attrs, Some(body)))?
@@ -1574,7 +1573,9 @@ impl<'a> Parser<'a> {
                 .emit();
             (Vec::new(), Some(self.mk_block_err(span)))
         } else {
-            return self.expected_semi_or_open_brace();
+            return self
+                .expected_one_of_not_found(&[], &[token::Semi, token::OpenDelim(token::Brace)])
+                .map(|_| None);
         };
         attrs.extend(inner_attrs);
         Ok(body)

src/test/ui/issues/issue-39616.rs

@@ -1,4 +1,4 @@
 fn foo(a: [0; 1]) {} //~ ERROR expected type, found `0`
-//~| ERROR expected `;` or `{`, found `]`
+//~| ERROR expected one of `)`, `,`, `->`, `;`, `where`, or `{`, found `]`
 
 fn main() {}

src/test/ui/issues/issue-39616.stderr

@@ -4,11 +4,11 @@ error: expected type, found `0`
 LL | fn foo(a: [0; 1]) {}
    |            ^ expected type
 
-error: expected `;` or `{`, found `]`
+error: expected one of `)`, `,`, `->`, `;`, `where`, or `{`, found `]`
   --> $DIR/issue-39616.rs:1:16
    |
 LL | fn foo(a: [0; 1]) {}
-   |                ^ expected `;` or `{`
+   |                ^ expected one of `)`, `,`, `->`, `;`, `where`, or `{`
 
 error: aborting due to 2 previous errors
 

src/test/ui/issues/issue-58856-1.rs

@@ -2,7 +2,7 @@ impl A {
     //~^ ERROR cannot find type `A` in this scope
     fn b(self>
     //~^ ERROR expected one of `)`, `,`, or `:`, found `>`
-    //~| ERROR expected `;` or `{`, found `>`
+    //~| ERROR expected one of `->`, `;`, `where`, or `{`, found `>`
 }
 
 fn main() {}

src/test/ui/issues/issue-58856-1.stderr

@@ -6,14 +6,14 @@ LL |     fn b(self>
    |         |
    |         unclosed delimiter
 
-error: expected `;` or `{`, found `>`
+error: expected one of `->`, `;`, `where`, or `{`, found `>`
   --> $DIR/issue-58856-1.rs:3:14
    |
 LL | impl A {
    |        - while parsing this item list starting here
 LL |
 LL |     fn b(self>
-   |              ^ expected `;` or `{`
+   |              ^ expected one of `->`, `;`, `where`, or `{`
 ...
 LL | }
    | - the item list ends here

src/test/ui/parser/fn-colon-return-type.rs

@@ -0,0 +1,5 @@
+fn foo(x: i32): i32 { //~ ERROR expected one of `->`, `;`, `where`, or `{`, found `:`
+    x
+}
+
+fn main() {}

src/test/ui/parser/fn-colon-return-type.stderr

@@ -0,0 +1,8 @@
+error: expected one of `->`, `;`, `where`, or `{`, found `:`
+  --> $DIR/fn-colon-return-type.rs:1:15
+   |
+LL | fn foo(x: i32): i32 {
+   |               ^ expected one of `->`, `;`, `where`, or `{`
+
+error: aborting due to previous error
+

src/test/ui/parser/issue-24780.rs

@@ -3,6 +3,6 @@
 // expected one of ..., `>`, ... found `>`
 
 fn foo() -> Vec<usize>> {
-    //~^ ERROR expected `;` or `{`, found `>`
+    //~^ ERROR expected one of `!`, `+`, `::`, `;`, `where`, or `{`, found `>`
     Vec::new()
 }

src/test/ui/parser/issue-24780.stderr

@@ -1,8 +1,8 @@
-error: expected `;` or `{`, found `>`
+error: expected one of `!`, `+`, `::`, `;`, `where`, or `{`, found `>`
   --> $DIR/issue-24780.rs:5:23
    |
 LL | fn foo() -> Vec<usize>> {
-   |                       ^ expected `;` or `{`
+   |                       ^ expected one of `!`, `+`, `::`, `;`, `where`, or `{`
 
 error: aborting due to previous error