Parse ident with allowing recovery when trying to recover in diagnosing

(cherry picked from commit 3713512217)

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -2264,7 +2264,7 @@ impl<'a> Parser<'a> {
             && self.look_ahead(1, |t| *t == token::Comma || *t == token::CloseParen)
         {
             // `fn foo(String s) {}`
-            let ident = self.parse_ident().unwrap();
+            let ident = self.parse_ident_common(true).unwrap();
             let span = pat.span.with_hi(ident.span.hi());
 
             err.span_suggestion(

compiler/rustc_parse/src/parser/item.rs

@@ -408,12 +408,11 @@ impl<'a> Parser<'a> {
         let insert_span = ident_span.shrink_to_lo();
 
         let ident = if self.token.is_ident()
-            && self.token.is_non_reserved_ident()
             && (!is_const || self.look_ahead(1, |t| *t == token::OpenParen))
             && self.look_ahead(1, |t| {
                 matches!(t.kind, token::Lt | token::OpenBrace | token::OpenParen)
             }) {
-            self.parse_ident().unwrap()
+            self.parse_ident_common(true).unwrap()
         } else {
             return Ok(());
         };

compiler/rustc_parse/src/parser/mod.rs

@@ -469,7 +469,7 @@ impl<'a> Parser<'a> {
         self.parse_ident_common(self.may_recover())
     }
 
-    fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, Ident> {
+    pub(crate) fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, Ident> {
         let (ident, is_raw) = self.ident_or_err(recover)?;
 
         if is_raw == IdentIsRaw::No && ident.is_reserved() {

tests/ui/parser/macro/kw-in-const-item-pos-recovery-149692.rs

@@ -6,6 +6,7 @@ macro_rules! m {
 }
 
 m!(const Self());
-//~^ ERROR expected one of `!` or `::`, found `(`
+//~^ ERROR expected identifier, found keyword `Self`
+//~^^ ERROR missing `fn` or `struct` for function or struct definition
 
 fn main() {}

tests/ui/parser/macro/kw-in-const-item-pos-recovery-149692.stderr

@@ -1,11 +1,22 @@
-error: expected one of `!` or `::`, found `(`
+error: expected identifier, found keyword `Self`
-  --> $DIR/kw-in-const-item-pos-recovery-149692.rs:8:14
+  --> $DIR/kw-in-const-item-pos-recovery-149692.rs:8:10
+   |
+LL | m!(const Self());
+   |          ^^^^ expected identifier, found keyword
+
+error: missing `fn` or `struct` for function or struct definition
+  --> $DIR/kw-in-const-item-pos-recovery-149692.rs:8:10
    |
 LL |     (const $id:item()) => {}
    |            -------- while parsing argument for this `item` macro fragment
 ...
 LL | m!(const Self());
-   |              ^ expected one of `!` or `::`
+   |          ^^^^
+   |
+help: if you meant to call a macro, try
+   |
+LL | m!(const Self!());
+   |              +
 
-error: aborting due to 1 previous error
+error: aborting due to 2 previous errors
 

tests/ui/parser/macro/kw-in-item-pos-recovery-149692.rs

@@ -8,12 +8,15 @@ macro_rules! m {
 }
 
 m!(Self());
-//~^ ERROR expected one of `!` or `::`, found `(`
+//~^ ERROR expected identifier, found keyword `Self`
+//~^^ ERROR missing `fn` or `struct` for function or struct definition
 
 m!(Self{});
-//~^ ERROR expected one of `!` or `::`, found `{`
+//~^ ERROR expected identifier, found keyword `Self`
+//~^^ ERROR missing `enum` or `struct` for enum or struct definition
 
 m!(crate());
-//~^ ERROR expected one of `!` or `::`, found `(`
+//~^ ERROR expected identifier, found keyword `crate`
+//~^^ ERROR missing `fn` or `struct` for function or struct definition
 
 fn main() {}

tests/ui/parser/macro/kw-in-item-pos-recovery-149692.stderr

@@ -1,29 +1,57 @@
-error: expected one of `!` or `::`, found `(`
+error: expected identifier, found keyword `Self`
-  --> $DIR/kw-in-item-pos-recovery-149692.rs:10:8
+  --> $DIR/kw-in-item-pos-recovery-149692.rs:10:4
+   |
+LL | m!(Self());
+   |    ^^^^ expected identifier, found keyword
+
+error: missing `fn` or `struct` for function or struct definition
+  --> $DIR/kw-in-item-pos-recovery-149692.rs:10:4
    |
 LL |     ($id:item()) => {}
    |      -------- while parsing argument for this `item` macro fragment
 ...
 LL | m!(Self());
-   |        ^ expected one of `!` or `::`
+   |    ^^^^
+   |
+help: if you meant to call a macro, try
+   |
+LL | m!(Self!());
+   |        +
 
-error: expected one of `!` or `::`, found `{`
+error: expected identifier, found keyword `Self`
-  --> $DIR/kw-in-item-pos-recovery-149692.rs:13:8
+  --> $DIR/kw-in-item-pos-recovery-149692.rs:14:4
+   |
+LL | m!(Self{});
+   |    ^^^^ expected identifier, found keyword
+
+error: missing `enum` or `struct` for enum or struct definition
+  --> $DIR/kw-in-item-pos-recovery-149692.rs:14:4
    |
 LL |     ($id:item()) => {}
    |      -------- while parsing argument for this `item` macro fragment
 ...
 LL | m!(Self{});
-   |        ^ expected one of `!` or `::`
+   |    ^^^^
 
-error: expected one of `!` or `::`, found `(`
+error: expected identifier, found keyword `crate`
-  --> $DIR/kw-in-item-pos-recovery-149692.rs:16:9
+  --> $DIR/kw-in-item-pos-recovery-149692.rs:18:4
+   |
+LL | m!(crate());
+   |    ^^^^^ expected identifier, found keyword
+
+error: missing `fn` or `struct` for function or struct definition
+  --> $DIR/kw-in-item-pos-recovery-149692.rs:18:4
    |
 LL |     ($id:item()) => {}
    |      -------- while parsing argument for this `item` macro fragment
 ...
 LL | m!(crate());
-   |         ^ expected one of `!` or `::`
+   |    ^^^^^
+   |
+help: if you meant to call a macro, try
+   |
+LL | m!(crate!());
+   |         +
 
-error: aborting due to 3 previous errors
+error: aborting due to 6 previous errors
 

tests/ui/parser/macro/kw-in-item-pos-recovery-151238.rs

@@ -0,0 +1,13 @@
+//@ edition: 2021
+
+macro_rules! x {
+    ($ty : item) => {};
+}
+x! {
+  trait MyTrait { fn bar(c self) }
+  //~^ ERROR expected identifier, found keyword `self`
+  //~^^ ERROR expected one of `:`, `@`, or `|`, found keyword `self`
+  //~^^^ ERROR expected one of `->`, `;`, `where`, or `{`, found `}`
+}
+
+fn main() {}

tests/ui/parser/macro/kw-in-item-pos-recovery-151238.stderr

@@ -0,0 +1,25 @@
+error: expected identifier, found keyword `self`
+  --> $DIR/kw-in-item-pos-recovery-151238.rs:7:28
+   |
+LL |   trait MyTrait { fn bar(c self) }
+   |                            ^^^^ expected identifier, found keyword
+
+error: expected one of `:`, `@`, or `|`, found keyword `self`
+  --> $DIR/kw-in-item-pos-recovery-151238.rs:7:28
+   |
+LL |   trait MyTrait { fn bar(c self) }
+   |                          --^^^^
+   |                          | |
+   |                          | expected one of `:`, `@`, or `|`
+   |                          help: declare the type after the parameter binding: `<identifier>: <type>`
+
+error: expected one of `->`, `;`, `where`, or `{`, found `}`
+  --> $DIR/kw-in-item-pos-recovery-151238.rs:7:34
+   |
+LL |   trait MyTrait { fn bar(c self) }
+   |                      ---         ^ expected one of `->`, `;`, `where`, or `{`
+   |                      |
+   |                      while parsing this `fn`
+
+error: aborting due to 3 previous errors
+