Auto merge of #119384 - matthiaskrgr:rollup-hhz9ws0, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - #119331 (rustdoc-search: count path edits with separate edit limit)
 - #119359 (Simplify Parser::ident_or_error)
 - #119376 (Add regression test for #106630)
 - #119379 (Update `parse_seq` doc)
 - #119380 (Don't suggest writing a bodyless arm if the pattern can never be a never pattern)

r? `@ghost`
`@rustbot` modify labels: rollup

2 files changed, 39 insertions, 23 deletions

diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 73bd19f34c1..bf6151b64d3 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -2937,7 +2937,13 @@ impl<'a> Parser<'a> {
             let is_almost_fat_arrow = TokenKind::FatArrow
                 .similar_tokens()
                 .is_some_and(|similar_tokens| similar_tokens.contains(&this.token.kind));
-            let mut result = if !is_fat_arrow && !is_almost_fat_arrow {
+
+            // this avoids the compiler saying that a `,` or `}` was expected even though
+            // the pattern isn't a never pattern (and thus an arm body is required)
+            let armless = (!is_fat_arrow && !is_almost_fat_arrow && pat.could_be_never_pattern())
+                || matches!(this.token.kind, token::Comma | token::CloseDelim(Delimiter::Brace));
+
+            let mut result = if armless {
                 // A pattern without a body, allowed for never patterns.
                 arm_body = None;
                 this.expect_one_of(&[token::Comma], &[token::CloseDelim(Delimiter::Brace)]).map(
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index 1598fd19f6d..19226f37abe 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -320,9 +320,15 @@ impl TokenType {
     }
 }
 
+/// Used by [`Parser::expect_any_with_type`].
 #[derive(Copy, Clone, Debug)]
 enum TokenExpectType {
+    /// Unencountered tokens are inserted into [`Parser::expected_tokens`].
+    /// See [`Parser::check`].
     Expect,
+
+    /// Unencountered tokens are not inserted into [`Parser::expected_tokens`].
+    /// See [`Parser::check_noexpect`].
     NoExpect,
 }
 
@@ -504,18 +510,10 @@ impl<'a> Parser<'a> {
     }
 
     fn ident_or_err(&mut self, recover: bool) -> PResult<'a, (Ident, /* is_raw */ bool)> {
-        let result = self.token.ident().ok_or_else(|| self.expected_ident_found(recover));
-
-        let (ident, is_raw) = match result {
-            Ok(ident) => ident,
-            Err(err) => match err {
-                // we recovered!
-                Ok(ident) => ident,
-                Err(err) => return Err(err),
-            },
-        };
-
-        Ok((ident, is_raw))
+        match self.token.ident() {
+            Some(ident) => Ok(ident),
+            None => self.expected_ident_found(recover),
+        }
     }
 
     /// Checks if the next token is `tok`, and returns `true` if so.
@@ -766,13 +764,17 @@ impl<'a> Parser<'a> {
         }
     }
 
+    /// Checks if the next token is contained within `kets`, and returns `true` if so.
     fn expect_any_with_type(&mut self, kets: &[&TokenKind], expect: TokenExpectType) -> bool {
         kets.iter().any(|k| match expect {
             TokenExpectType::Expect => self.check(k),
-            TokenExpectType::NoExpect => self.token == **k,
+            TokenExpectType::NoExpect => self.check_noexpect(k),
         })
     }
 
+    /// Parses a sequence until the specified delimiters. The function
+    /// `f` must consume tokens until reaching the next separator or
+    /// closing bracket.
     fn parse_seq_to_before_tokens<T>(
         &mut self,
         kets: &[&TokenKind],
@@ -791,13 +793,15 @@ impl<'a> Parser<'a> {
             }
             if let Some(t) = &sep.sep {
                 if first {
+                    // no separator for the first element
                     first = false;
                 } else {
+                    // check for separator
                     match self.expect(t) {
-                        Ok(false) => {
+                        Ok(false) /* not recovered */ => {
                             self.current_closure.take();
                         }
-                        Ok(true) => {
+                        Ok(true) /* recovered */ => {
                             self.current_closure.take();
                             recovered = true;
                             break;
@@ -965,7 +969,7 @@ impl<'a> Parser<'a> {
         Ok(())
     }
 
-    /// Parses a sequence, not including the closing delimiter. The function
+    /// Parses a sequence, not including the delimiters. The function
     /// `f` must consume tokens until reaching the next separator or
     /// closing bracket.
     fn parse_seq_to_before_end<T>(
@@ -973,11 +977,11 @@ impl<'a> Parser<'a> {
         ket: &TokenKind,
         sep: SeqSep,
         f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
-    ) -> PResult<'a, (ThinVec<T>, bool, bool)> {
+    ) -> PResult<'a, (ThinVec<T>, bool /* trailing */, bool /* recovered */)> {
         self.parse_seq_to_before_tokens(&[ket], sep, TokenExpectType::Expect, f)
     }
 
-    /// Parses a sequence, including the closing delimiter. The function
+    /// Parses a sequence, including only the closing delimiter. The function
     /// `f` must consume tokens until reaching the next separator or
     /// closing bracket.
     fn parse_seq_to_end<T>(
@@ -993,7 +997,7 @@ impl<'a> Parser<'a> {
         Ok((val, trailing))
     }
 
-    /// Parses a sequence, including the closing delimiter. The function
+    /// Parses a sequence, including both delimiters. The function
     /// `f` must consume tokens until reaching the next separator or
     /// closing bracket.
     fn parse_unspanned_seq<T>(
@@ -1002,16 +1006,19 @@ impl<'a> Parser<'a> {
         ket: &TokenKind,
         sep: SeqSep,
         f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
-    ) -> PResult<'a, (ThinVec<T>, bool)> {
+    ) -> PResult<'a, (ThinVec<T>, bool /* trailing */)> {
         self.expect(bra)?;
         self.parse_seq_to_end(ket, sep, f)
     }
 
+    /// Parses a comma-separated sequence, including both delimiters.
+    /// The function `f` must consume tokens until reaching the next separator or
+    /// closing bracket.
     fn parse_delim_comma_seq<T>(
         &mut self,
         delim: Delimiter,
         f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
-    ) -> PResult<'a, (ThinVec<T>, bool)> {
+    ) -> PResult<'a, (ThinVec<T>, bool /* trailing */)> {
         self.parse_unspanned_seq(
             &token::OpenDelim(delim),
             &token::CloseDelim(delim),
@@ -1020,10 +1027,13 @@ impl<'a> Parser<'a> {
         )
     }
 
+    /// Parses a comma-separated sequence delimited by parentheses (e.g. `(x, y)`).
+    /// The function `f` must consume tokens until reaching the next separator or
+    /// closing bracket.
     fn parse_paren_comma_seq<T>(
         &mut self,
         f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
-    ) -> PResult<'a, (ThinVec<T>, bool)> {
+    ) -> PResult<'a, (ThinVec<T>, bool /* trailing */)> {
         self.parse_delim_comma_seq(Delimiter::Parenthesis, f)
     }