Dont suggest converting /// to regular comment when it appears after missing , in list

Signed-off-by: xizheyin <[email protected]>

Author: xizheyin

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -686,23 +686,35 @@ impl<'a> Parser<'a> {
         }
 
         if let token::DocComment(kind, style, _) = self.token.kind {
-            // We have something like `expr //!val` where the user likely meant `expr // !val`
-            let pos = self.token.span.lo() + BytePos(2);
-            let span = self.token.span.with_lo(pos).with_hi(pos);
-            err.span_suggestion_verbose(
-                span,
-                format!(
-                    "add a space before {} to write a regular comment",
-                    match (kind, style) {
-                        (token::CommentKind::Line, ast::AttrStyle::Inner) => "`!`",
-                        (token::CommentKind::Block, ast::AttrStyle::Inner) => "`!`",
-                        (token::CommentKind::Line, ast::AttrStyle::Outer) => "the last `/`",
-                        (token::CommentKind::Block, ast::AttrStyle::Outer) => "the last `*`",
-                    },
-                ),
-                " ".to_string(),
-                Applicability::MachineApplicable,
-            );
+            // This is used to adding suggestions for doc comments in list.
+            // For example,
+            // `enum Foo {
+            //     Bar ///baz
+            //     Baz }`
+            // or `[
+            //     expr ///baz
+            //     expr2
+            // ]`
+            // should suggest to add a comma before `///baz`.
+            if !expected.contains(&TokenType::Comma) {
+                // We have something like `expr //!val` where the user likely meant `expr // !val`
+                let pos = self.token.span.lo() + BytePos(2);
+                let span = self.token.span.with_lo(pos).with_hi(pos);
+                err.span_suggestion_verbose(
+                    span,
+                    format!(
+                        "add a space before {} to write a regular comment",
+                        match (kind, style) {
+                            (token::CommentKind::Line, ast::AttrStyle::Inner) => "`!`",
+                            (token::CommentKind::Block, ast::AttrStyle::Inner) => "`!`",
+                            (token::CommentKind::Line, ast::AttrStyle::Outer) => "the last `/`",
+                            (token::CommentKind::Block, ast::AttrStyle::Outer) => "the last `*`",
+                        },
+                    ),
+                    " ".to_string(),
+                    Applicability::MaybeIncorrect,
+                );
+            }
         }
 
         let sp = if self.token == token::Eof {

tests/ui/parser/doc-comment-after-missing-comma-issue-142311.stderr

@@ -2,33 +2,21 @@ error: expected one of `(`, `,`, `=`, `{`, or `}`, found doc comment `/// Like w
   --> $DIR/doc-comment-after-missing-comma-issue-142311.rs:10:5
    |
 LL |     Bar
-   |        - expected one of `(`, `,`, `=`, `{`, or `}`
+   |        -
+   |        |
+   |        expected one of `(`, `,`, `=`, `{`, or `}`
+   |        help: missing `,`
 LL |     /// Like where people drink
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ unexpected token
-   |
-help: add a space before the last `/` to write a regular comment
-   |
-LL |     // / Like where people drink
-   |       +
-help: missing `,`
-   |
-LL |     Bar,
-   |        +
 
 error: expected one of `(`, `,`, `=`, `{`, or `}`, found doc comment `///xxxxxx`
   --> $DIR/doc-comment-after-missing-comma-issue-142311.rs:12:8
    |
 LL |     Baa///xxxxxx
-   |        ^^^^^^^^^ expected one of `(`, `,`, `=`, `{`, or `}`
-   |
-help: add a space before the last `/` to write a regular comment
-   |
-LL |     Baa// /xxxxxx
-   |          +
-help: missing `,`
-   |
-LL |     Baa,///xxxxxx
-   |        +
+   |        -^^^^^^^^
+   |        |
+   |        expected one of `(`, `,`, `=`, `{`, or `}`
+   |        help: missing `,`
 
 error: expected one of `(`, `,`, `=`, `{`, or `}`, found doc comment `///xxxxxx`
   --> $DIR/doc-comment-after-missing-comma-issue-142311.rs:14:8
@@ -38,32 +26,18 @@ LL |     Baz///xxxxxx
    |
    = help: doc comments must come before what they document, if a comment was intended use `//`
    = help: enum variants can be `Variant`, `Variant = <integer>`, `Variant(Type, ..., TypeN)` or `Variant { fields: Types }`
-help: add a space before the last `/` to write a regular comment
-   |
-LL |     Baz// /xxxxxx
-   |          +
 
 error: expected one of `,`, `.`, `;`, `?`, `]`, or an operator, found doc comment `///xxxxxx`
   --> $DIR/doc-comment-after-missing-comma-issue-142311.rs:20:10
    |
 LL |         1///xxxxxx
    |          ^^^^^^^^^ expected one of `,`, `.`, `;`, `?`, `]`, or an operator
-   |
-help: add a space before the last `/` to write a regular comment
-   |
-LL |         1// /xxxxxx
-   |            +
 
 error: expected one of `,`, `.`, `?`, `]`, or an operator, found doc comment `///xxxxxx`
   --> $DIR/doc-comment-after-missing-comma-issue-142311.rs:29:10
    |
 LL |         2///xxxxxx
    |          ^^^^^^^^^ expected one of `,`, `.`, `?`, `]`, or an operator
-   |
-help: add a space before the last `/` to write a regular comment
-   |
-LL |         2// /xxxxxx
-   |            +
 
 error: aborting due to 5 previous errors